OXYGEN TRANSPORT CERAMIC MEMBRANES

Energy Technology Data Exchange (ETDEWEB)

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2000-10-01

This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

Reclaimed wastewater quality enhancement by oxygen injection during transportation.

Science.gov (United States)

Rodríguez-Gómez, L E; Alvarez, M; Rodríguez-Sevilla, J; Marrero, M C; Hernández, A

2011-01-01

In-sewer treatments have been studied in sewer systems, but few have been carried out on reclaimed wastewater systems. A study of oxygen injection has been performed in a completely filled gravity pipe, 0.6 m in diameter and 62 km long, in cast iron with concrete inside coating, which is part of the reclaimed wastewater reuse scheme of Tenerife (Spain). A high pressure oxygen injection system was installed at 16.0 km from pipe inlet and a constant dosage of 30 mg/L O(2) has been injected during six months, under three different operational modes (low COD, 63 mg/L; high COD, 91 mg/L; and partially nitrified water). Oxygen has been consumed in nitrification and organic matter reduction. Generally, nitrification is clearly favored instead of the organic matter oxidation. Nitrification occurs, in general, with nitrite accumulation due to the presence of free ammonia above 1 mg/L. Denitrification is in all cases incomplete due to a limitation of easily biodegradable organic matter content, inhibiting the appearance of anaerobic conditions and sulfide generation. A notable reduction of organic matter parameters is achieved (TSS below 10 mg/L), which is significantly higher than that observed under the ordinary transport conditions without oxygen. This leads to a final cost reduction, and the oxygen injection system helps water reuse managers to maintain a final good water quality in the case of a treatment plant malfunction.

Oxygen Transport: A Simple Model for Study and Examination.

Science.gov (United States)

Gaar, Kermit A., Jr.

1985-01-01

Describes an oxygen transport model computer program (written in Applesoft BASIC) which uses such variables as amount of time lapse from beginning of the simulation, arterial blood oxygen concentration, alveolar oxygen pressure, and venous blood oxygen concentration and pressure. Includes information on obtaining the program and its documentation.…

Oxygen Transport Membranes

Energy Technology Data Exchange (ETDEWEB)

S. Bandopadhyay

2008-08-30

The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

Enhancing oxygen transport through Mixed-Ionic-and-Electronic-Conducting ceramic membranes

Science.gov (United States)

Yu, Anthony S.

Ceramic membranes based on Mixed-Ionic-and-Electronic-Conducting (MIEC) oxides are capable of separating oxygen from air in the presence of an oxygen partial-pressure gradient. These MIEC membranes show great promise for oxygen consuming industrial processes, such as the production of syngas from steam reforming of natural gas (SRM), as well as for electricity generation in Solid Oxide Fuel Cells (SOFC). For both applications, the overall performance is dictated by the rate of oxygen transport across the membrane. Oxygen transport across MIEC membranes is composed of a bulk oxygen-ion diffusion process and surface processes, such as surface reactions and adsorption/desorption of gaseous reactants/products. The main goal of this thesis was to determine which process is rate-limiting in order to significantly enhance the overall rate of oxygen transport in MIEC membrane systems. The rate-limiting step was determined by evaluating the total resistance to oxygen transfer, Rtot. Rtot is the sum of a bulk diffusion resistance in the membrane itself, Rb, and interfacial loss components, Rs. Rb is a function of the membrane's ionic conductivity and thickness, while Rs arises primarily from slow surface-exchange kinetics that cause the P(O2) at the surfaces of the membrane to differ from the P(O 2) in the adjacent gas phases. Rtot can be calculated from the Nernst potential across the membrane and the measured oxygen flux. The rate-limiting process can be determined by evaluating the relative contributions of the various losses, Rs and Rb, to Rtot. Using this method, this thesis demonstrates that for most membrane systems, Rs is the dominating factor. In the development of membrane systems with high oxygen transport rates, thin membranes with high ionic conductivities are required to achieve fast bulk oxygen-ion diffusion. However, as membrane thickness is decreased, surface reaction kinetics become more important in determining the overall transport rate. The two

Spin transport in oxygen adsorbed graphene nanoribbon

Science.gov (United States)

Kumar, Vipin

2018-04-01

The spin transport properties of pristine graphene nanoribbons (GNRs) have been most widely studied using theoretical and experimental tools. The possibilities of oxidation of fabricated graphene based nano electronic devices may change the device characteristics, which motivates to further explore the properties of graphene oxide nanoribbons (GONRs). Therefore, we present a systematic computational study on the spin polarized transport in surface oxidized GNR in antiferromagnetic (AFM) spin configuration using density functional theory combined with non-equilibrium Green's function (NEGF) method. It is found that the conductance in oxidized GNRs is significantly suppressed in the valance band and the conduction band. A further reduction in the conductance profile is seen in presence of two oxygen atoms on the ribbon plane. This change in the conductance may be attributed to change in the surface topology of the ribbon basal plane due to presence of the oxygen adatoms, where the charge transfer take place between the ribbon basal plane and the oxygen atoms.

Hollow Nanospheres with Fluorous Interiors for Transport of Molecular Oxygen in Water

KAUST Repository

Vu, Khanh B.

2016-08-11

A dispersion system for saturated fluorocarbon (SFC) liquids based on permeable hollow nanospheres with fluorous interiors is described. The nanospheres are well dispersible in water and are capable of immediate uptake of SFCs. The nanosphere shells are gas-permeable and feature reactive functional groups for easy modification of the exterior. These features make the SFC-filled nanospheres promising vehicles for respiratory oxygen storage and transport. Uptake of molecular oxygen into nanosphere-stabilized SFC dispersions is demonstrated.

Effects of whole-body gamma irradiation on oxygen transport by rat erythrocytes

International Nuclear Information System (INIS)

Thiriot, Christian; Kergonou, J.F.; Rocquet, Guy; Allary, Michel; Saint-Blancard, Jacques

1982-01-01

In this work, we studied the influence of whole-body gamma irradiation (8 Gy) upon oxygen transport by erythrocytes, through the erythrocyte count and related parameters, and through the factors affecting the oxygen affinity of hemoglobin. The oxygen affinity of hemoglobin is increased from day D + 5 after irradiation, and a severe erythropenia develops from day D + 8. These modifications probably result in tissue hypoxia via diminished oxygen transport from lungs to tissues, and decreased oxygen release from oxyhemoglobin in tissues

Intramyocardial oxygen transport by quantitative diffuse reflectance spectroscopy in calves

Science.gov (United States)

Lindbergh, Tobias; Larsson, Marcus; Szabó, Zoltán; Casimir-Ahn, Henrik; Strömberg, Tomas

2010-03-01

Intramyocardial oxygen transport was assessed during open-chest surgery in calves by diffuse reflectance spectroscopy using a small intramuscular fiber-optic probe. The sum of hemo- and myoglobin tissue fraction and oxygen saturation, the tissue fraction and oxidation of cytochrome aa3, and the tissue fraction of methemoglobin were estimated using a calibrated empirical light transport model. Increasing the oxygen content in the inhaled gas, 21%-50%-100%, in five calves (group A) gave an increasing oxygen saturation of 19+/-4%, 24+/-5%, and 28+/-8% (panimals increased with LVAD pump speed (p<0.001, ANOVA) and with oxygen content in inhaled gas (p<0.001, ANOVA). The cytochrome aa3 oxidation level was above 96% in both group A and group B calves, including the two cases involving cardiac arrest. In conclusion, the estimated tissue fractions and oxygenation/oxidation levels of the myocardial chromophores during respiratory and hemodynamic provocations were in agreement with previously presented results, demonstrating the potential of the method.

Carbogen inhalation increases oxygen transport to hypoperfused brain tissue in patients with occlusive carotid artery disease: increased oxygen transport to hypoperfused brain

DEFF Research Database (Denmark)

Ashkanian, Mahmoud; Gjedde, Albert; Mouridsen, Kim

2009-01-01

to inhaled oxygen (the mixture known as carbogen). In the present study, we measured CBF by positron emission tomography (PET) during inhalation of test gases (O(2), carbogen, and atmospheric air) in healthy volunteers (n = 10) and in patients with occlusive carotid artery disease (n = 6). Statistical...... and Sa(O2) are readily obtained with carbogen, while oxygen increases only Sa(O2). Thus, carbogen improves oxygen transport to brain tissue more efficiently than oxygen alone. Further studies with more subjects are, however, needed to investigate the applicability of carbogen for long-term inhalation...

Efficiency increase of complex production and transport systems management

Directory of Open Access Journals (Sweden)

Kornilov S.

2017-01-01

Full Text Available This article deals with the problem of the reduced efficiency of management in complex production - transport systems due to the lack of co-ordination in the operation of industrial enterprises and transport carrying out their maintenance. The existing transport service schedules for auxiliary departments do not take into account possible changes in operating conditions, the probability of malfunctions and the amount of reserves, which leads to an increase in general production costs. To solve this problem, we propose to use the interval regulation of production and transport processes in all departments of the complex production and transport systems. Also, such regulation involves the determination of traffic service priority. This will allow passing on from the regulated control of production and transport processes to the situational one, adapted to specific conditions, and reducing losses from untimely transport servicing, which will lead to a stores reduction and efficiency increase of the enterprise circulating facilities use. Testing the effectiveness of interval regulation was performed on the system and dynamics simulation model of liquid iron transportation in the oxygen converter shop of the metallurgical enterprise. It was established that the use of interval regulation processes in iron production and its transportation will allow decreasing non-productive downtime by 21% and the amount of the liquid iron in anticipation of recasting in the oxygen converter shop – by 33%. Economical effect of reducing the liquid iron downtime during transportation to the oxygen converter shop will be about 30 million rubles per year.

Effect of oxygenated perfluorocarbon on isolated islets during transportation.

Science.gov (United States)

Terai, Sachio; Tsujimura, Toshiaki; Li, Shiri; Hori, Yuichi; Toyama, Hirochika; Shinzeki, Makoto; Matsumoto, Ippei; Kuroda, Yoshikazu; Ku, Yonson

2010-08-01

Previous studies demonstrated the efficacy of the two-layer method (TLM) using oxygenated perfluorochemicals (PFC) for pancreas preservation. The current study investigated the effect of oxygenated PFC on isolated islets during transportation. Purified rat islets were stored in an airtight conical tube for 24h in RPMI culture medium at 22 degrees C or University of Wisconsin solution (UW) at 4 degrees C, either with or without oxygenated PFC. After storage, the islets were assessed for in vitro viability by static incubation (SI), FDA/PI staining, and energy status (ATP, energy charge, and ADP/ATP ratio) and for in vivo viability by a transplantation study. UW at 4 degrees C and RPMI medium at 22 degrees C maintained islet quality almost equally in both in vitro and in vivo assessments. The ATP levels and energy status in the groups with PFC were significantly lower than those without PFC. The groups with PFC showed a significantly higher ADP/ATP ratio than those without PFC. In the transplantation study, blood glucose levels and AUC in the UW+PFC group were significantly higher than those in UW group. UW at 4 degrees C and RPMI medium at 22 degrees C maintained islet quality equally under the conditions for islet transportation. The addition of oxygenated PFC, while advantageous for pancreas preservation, is not useful for islet transportation. Copyright 2010 Elsevier Inc. All rights reserved.

Catalyst containing oxygen transport membrane

Science.gov (United States)

Christie, Gervase Maxwell; Wilson, Jamie Robyn; van Hassel, Bart Antonie

2012-12-04

A composite oxygen transport membrane having a dense layer, a porous support layer and an intermediate porous layer located between the dense layer and the porous support layer. Both the dense layer and the intermediate porous layer are formed from an ionic conductive material to conduct oxygen ions and an electrically conductive material to conduct electrons. The porous support layer has a high permeability, high porosity, and a high average pore diameter and the intermediate porous layer has a lower permeability and lower pore diameter than the porous support layer. Catalyst particles selected to promote oxidation of a combustible substance are located in the intermediate porous layer and in the porous support adjacent to the intermediate porous layer. The catalyst particles can be formed by wicking a solution of catalyst precursors through the porous support toward the intermediate porous layer.

Surface oxygen vacancy and oxygen permeation flux limits of perovskite ion transport membranes

KAUST Repository

Hunt, Anton; Dimitrakopoulos, Georgios; Ghoniem, Ahmed F.

2015-01-01

© 2015 Elsevier B.V. The mechanisms and quantitative models for how oxygen is separated from air using ion transport membranes (ITMs) are not well understood, largely due to the experimental complexity for determining surface exchange reactions

Effect of hemodialysis on factors influencing oxygen transport.

Science.gov (United States)

Hirszel, P; Maher, J F; Tempel, G E; Mengel, C E

1975-06-01

Ten patients underwent 4 study hemodialyses, one with standard dialysis conditions, one with an isophosphate dialysate, one with simultaneous ammonium chloride loading, and other, after pretreatment, with sodium bicarbonate. Measurement of hemoglobin oxygen affinity (P-50), erythrocyte 2,3-DPG, blood-gasses, and serum chemistries revealed biochemically effective hemodialyses and slight changes in oxygen transport parameters. The P-50 (in vivo) values decreased slightly but significantly (p greater than 0.05) with dialysis. When corrected to pH 7.4, eliminating the Bohr effect, P-50 increased (p greater than 0.05). With unmodified dialysis elevated values of 2,3-DPG (in comparison to normal) decreased, a change that did not correlate with delta-p-50, delta-serum phosphate, or delta-serum creatinine. With standard and isophosphate dialyses Po-2 decreased significantly. The decrease correlated with delta-hydrogen ion concentration and did not occur with dialyses designed to maintain pH constant. Thus, hemodialysis influences many factors that affect oxygen transport in different and counterbalancing directions. These changes are not totally explained by alterations in 2,3-DPG, pH or serum phosphate. Maintenance of acidosis or hyperphosphatemia during dialysis is not recommended.

Oxygen transport in La1-xSrxFe1-yMnyO3-δ perovskites

DEFF Research Database (Denmark)

Mikkelsen, L.; Andersen, I.G.K.; Skou, E.M.

2002-01-01

The oxygen transport in La1-xSrxFe1-yMnyO3-delta (LSFM) with 0 less than or equal to x less than or equal to 0.5 and y = 0.2 and 03 has been examined with a thermogravimetric method. As long as x less than or equal to y, the oxygen transport was found to be very slow while the oxygen transport in...

The Pathway for Oxygen: Tutorial Modelling on Oxygen Transport from Air to Mitochondrion: The Pathway for Oxygen.

Science.gov (United States)

Bassingthwaighte, James B; Raymond, Gary M; Dash, Ranjan K; Beard, Daniel A; Nolan, Margaret

2016-01-01

The 'Pathway for Oxygen' is captured in a set of models describing quantitative relationships between fluxes and driving forces for the flux of oxygen from the external air source to the mitochondrial sink at cytochrome oxidase. The intervening processes involve convection, membrane permeation, diffusion of free and heme-bound O2 and enzymatic reactions. While this system's basic elements are simple: ventilation, alveolar gas exchange with blood, circulation of the blood, perfusion of an organ, uptake by tissue, and consumption by chemical reaction, integration of these pieces quickly becomes complex. This complexity led us to construct a tutorial on the ideas and principles; these first PathwayO2 models are simple but quantitative and cover: (1) a 'one-alveolus lung' with airway resistance, lung volume compliance, (2) bidirectional transport of solute gasses like O2 and CO2, (3) gas exchange between alveolar air and lung capillary blood, (4) gas solubility in blood, and circulation of blood through the capillary syncytium and back to the lung, and (5) blood-tissue gas exchange in capillaries. These open-source models are at Physiome.org and provide background for the many respiratory models there.

Computational Modeling of Oxygen Transport in the Microcirculation: From an Experiment-Based Model to Theoretical Analyses

OpenAIRE

Lücker, Adrien

2017-01-01

Oxygen supply to cells by the cardiovascular system involves multiple physical and chemical processes that aim to satisfy fluctuating metabolic demand. Regulation mechanisms range from increased heart rate to minute adaptations in the microvasculature. The challenges and limitations of experimental studies in vivo make computational models an invaluable complement. In this thesis, oxygen transport from capillaries to tissue is investigated using a new numerical model that is tailored for vali...

Optimisation of oxygen ion transport in materials for ceramic membrane devices.

Science.gov (United States)

Kilner, J A

2007-01-01

Oxygen transport in ceramic oxide materials has received much attention over the past few decades. Much of this interest has stemmed from the desire to construct high temperature electrochemical devices for energy conversion, an example being the solid oxide fuel cell. In order to achieve high performance for these devices, insights are needed in how to achieve optimum performance from the functional components such as the electrolytes and electrodes. This includes the optimisation of oxygen transport through the crystal lattice of electrode and electrolyte materials and across the homogeneous (grain boundary) and heterogeneous interfaces that exist in real devices. Strategies are discussed for the optimisation of these quantities and current problems in the characterisation of interfacial transport are explored.

A computational study of the effect of capillary network anastomoses and tortuosity on oxygen transport.

Science.gov (United States)

Goldman, D; Popel, A S

2000-09-21

The objective of this study was to investigate the effects of capillary network anastomoses and tortuosity on oxygen transport in skeletal muscle, as well as the importance of muscle fibers in determining the arrangement of parallel capillaries. Countercurrent flow and random capillary blockage (e.g. by white blood cells) were also studied. A general computational model was constructed to simulate oxygen transport from a network of blood vessels within a rectangular volume of tissue. A geometric model of the capillary network structure, based on hexagonally packed muscle fibers, was constructed to produce networks of straight unbranched capillaries, capillaries with anastomoses, and capillaries with tortuosity, in order to examine the effects of these geometric properties. Quantities examined included the tissue oxygen tension and the capillary oxyhemoglobin saturation. The computational model included a two-phase simulation of blood flow. Appropriate parameters were chosen for working hamster cheek-pouch retractor muscle. Our calculations showed that the muscle-fiber geometry was important in reducing oxygen transport heterogeneity, as was countercurrent flow. Tortuosity was found to increase tissue oxygenation, especially when combined with anastomoses. In the absence of tortuosity, anastomoses had little effect on oxygen transport under normal conditions, but significantly improved transport when vessel blockages were present. Copyright 2000 Academic Press.

pH-Sensitive Amphiphilic Block-Copolymers for Transport and Controlled Release of Oxygen

KAUST Repository

Patil, Yogesh Raghunath

2017-05-31

Saturated fluorocarbons, their derivatives and emulsions are capable of dissolving anomalously high amounts of oxygen and other gases. The mechanistic aspects of this remarkable effect remain to be explored experimentally. Here, the synthesis of a library of amphiphilic fluorous block-copolymers incorporating different fluorinated monomers is described, and the capacity of these copolymers for oxygen transport in water is systematically investigated. The structure of the fluorous monomer employed was found to have a profound effect on both the oxygen-carrying capacity and the gas release kinetics of the polymer emulsions. Furthermore, the release of O2 from the polymer dispersions could be triggered by changing the pH of the solution. This is the first example of a polymer-based system for controlled release of a non-polar, non-covalently entrapped respiratory gas.

pH-Sensitive Amphiphilic Block-Copolymers for Transport and Controlled Release of Oxygen

KAUST Repository

Patil, Yogesh Raghunath; Almahdali, Sarah; Vu, Khanh B.; Zapsas, Georgios; Hadjichristidis, Nikolaos; Rodionov, Valentin

2017-01-01

Saturated fluorocarbons, their derivatives and emulsions are capable of dissolving anomalously high amounts of oxygen and other gases. The mechanistic aspects of this remarkable effect remain to be explored experimentally. Here, the synthesis of a library of amphiphilic fluorous block-copolymers incorporating different fluorinated monomers is described, and the capacity of these copolymers for oxygen transport in water is systematically investigated. The structure of the fluorous monomer employed was found to have a profound effect on both the oxygen-carrying capacity and the gas release kinetics of the polymer emulsions. Furthermore, the release of O2 from the polymer dispersions could be triggered by changing the pH of the solution. This is the first example of a polymer-based system for controlled release of a non-polar, non-covalently entrapped respiratory gas.

Hollow Nanospheres with Fluorous Interiors for Transport of Molecular Oxygen in Water

KAUST Repository

Vu, Khanh B.; Chen, Tianyou; Almahdali, Sarah; Bukhriakov, Konstantin; Rodionov, Valentin

2016-01-01

are gas-permeable and feature reactive functional groups for easy modification of the exterior. These features make the SFC-filled nanospheres promising vehicles for respiratory oxygen storage and transport. Uptake of molecular oxygen into nanosphere

Oxygen dynamics and transport in the Mediterranean sponge Aplysina aerophoba

DEFF Research Database (Denmark)

Hoffmann, F.; Røy, Hans; Bayer, K.

2008-01-01

The Mediterranean sponge Aplysina aerophoba kept in aquaria or cultivation tanks can stop pumping for several hours or even days. To investigate changes in the chemical microenvironments, we measured oxygen profiles over the surface and into the tissue of pumping and non-pumping A. aerophoba...... specimens with Clark-type oxygen microelectrodes (tip diameters 18-30 μm). Total oxygen consumption rates of whole sponges were measured in closed chambers. These rates were used to back-calculate the oxygen distribution in a finite-element model. Combining direct measurements with calculations of diffusive...... flux and modeling revealed that the tissue of non-pumping sponges turns anoxic within 15 min, with the exception of a 1 mm surface layer where oxygen intrudes due to molecular diffusion over the sponge surface. Molecular diffusion is the only transport mechanism for oxygen into non-pumping sponges...

Oxygen transport properties estimation by DSMC-CT simulations

Energy Technology Data Exchange (ETDEWEB)

Bruno, Domenico [Istituto di Metodologie Inorganiche e dei Plasmi, Consiglio Nazionale delle Ricerche - Via G. Amendola, 122 - 70125 Bari (Italy); Frezzotti, Aldo; Ghiroldi, Gian Pietro [Dipartimento di Scienze e Tecnologie Aerospaziali, Politecnico di Milano - Via La Masa, 34 - 20156 Milano (Italy)

2014-12-09

Coupling DSMC simulations with classical trajectories calculations is emerging as a powerful tool to improve predictive capabilities of computational rarefied gas dynamics. The considerable increase of computational effort outlined in the early application of the method (Koura,1997) can be compensated by running simulations on massively parallel computers. In particular, GPU acceleration has been found quite effective in reducing computing time (Ferrigni,2012; Norman et al.,2013) of DSMC-CT simulations. The aim of the present work is to study rarefied Oxygen flows by modeling binary collisions through an accurate potential energy surface, obtained by molecular beams scattering (Aquilanti, et al.,1999). The accuracy of the method is assessed by calculating molecular Oxygen shear viscosity and heat conductivity following three different DSMC-CT simulation methods. In the first one, transport properties are obtained from DSMC-CT simulations of spontaneous fluctuation of an equilibrium state (Bruno et al, Phys. Fluids, 23, 093104, 2011). In the second method, the collision trajectory calculation is incorporated in a Monte Carlo integration procedure to evaluate the Taxman’s expressions for the transport properties of polyatomic gases (Taxman,1959). In the third, non-equilibrium zero and one-dimensional rarefied gas dynamic simulations are adopted and the transport properties are computed from the non-equilibrium fluxes of momentum and energy. The three methods provide close values of the transport properties, their estimated statistical error not exceeding 3%. The experimental values are slightly underestimated, the percentage deviation being, again, few percent.

Oxygen transport in waterlogged soils, Part I. Approaches to modelling soil and crop response to oxygen deficiency

International Nuclear Information System (INIS)

Obando Moncayo, F.H.

2004-01-01

This lecture outlines in a simple way the mathematics of various cases of diffusion which have been widely used in modelling soil aeration. Simplifications of the general equation of diffusion (Fick's law) giving two possible forms of the problem: planar or one-dimensional diffusion and radial diffusion are given. Furthermore, the solution of diffusion equation is obtained by the analogy to the problem of electrical flow (Ohm's law). Taking into consideration the soil respiration process, the continuity equation which accounts for the law of conservation of mass is solved. The purpose of this paper has been to review the interrelation soil structure-air movement in waterlogged clay soils, and its consequences on plant growth and crop production. Thus, the mathematics of diffusion is presented, and then its application to specific cases of soil aeration such as diffusion in the soil profile, soil aggregates and roots is given. The following assumptions are taken into consideration. Gas flow in soils is basically diffusion-dependent. Gas-phase diffusion is the major mechanism for vertical or longitudinal transport (long distance transport); this means, with depth Z in the soil profile (macro diffusion). For horizontal transport (short distance transport or micro diffusion) which is assumed to be in X direction; in this case, the geometry of aggregates and the liquid phase are the major components of resistance for diffusion. Soil aggregates and roots are considered to be spherical and cylindrical in shape respectively. Soil oxygen consumption, Sr, is taken to be independent of the oxygen concentration and considered to proceed at the same rate until oxygen supply drops to critical levels. Thus, aeration problems are assumed to begin when at any time, in the root zone, the oxygen diffusion rate, ODR, becomes less than 30x10 -8 g.cm -2 .sec -1 , or the value of redox potential Eh is less than +525 mv

Radial transport of high-energy oxygen ions into the deep inner magnetosphere observed by Van Allen Probes

Science.gov (United States)

Mitani, K.; Seki, K.; Keika, K.; Gkioulidou, M.; Lanzerotti, L. J.; Mitchell, D. G.; Kletzing, C.

2017-12-01

It is known that proton is main contributor of the ring current and oxygen ions can make significant contribution during major magnetic storms. Ions are supplied to the ring current by radial transport from the plasma sheet. Convective transport of lower-energy protons and diffusive transport of higher-energy protons were reported to contribute to the storm-time and quiet-time ring current respectively [e.g., Gkioulidou et al., 2016]. However, supply mechanisms of the oxygen ions are not clear. To characterize the supply of oxygen ions to the ring current during magnetic storms, we studied the properties of energetic proton and oxygen ion phase space densities (PSDs) for specific magnetic moment (μ) during the April 23-25, 2013, geomagnetic storm observed by the Van Allen Probes mission. We here report on radial transport of high-energy (μ ≥ 0.5 keV/nT) oxygen ions into the deep inner magnetosphere during the late main phase of the magnetic storm. Since protons show little change during this period, this oxygen radial transport is inferred to cause the development of the late main phase. Enhancement of poloidal magnetic fluctuations is simultaneously observed. We estimated azimuthal mode number ≤5 by using cross wavelet analysis with ground-based observation of IMAGE ground magnetometers. The fluctuations can resonate with drift and bounce motions of the oxygen ions. The results suggest that combination of the drift and drift-bounce resonances is responsible for the radial transport of high-energy oxygen ions into the deep inner magnetosphere. We also report on the radial transport of the high-energy oxygen ions into the deep inner magnetosphere during other magnetic storms.

Modeling of Cerebral Oxygen Transport Based on In vivo Microscopic Imaging of Microvascular Network Structure, Blood Flow, and Oxygenation.

Science.gov (United States)

Gagnon, Louis; Smith, Amy F; Boas, David A; Devor, Anna; Secomb, Timothy W; Sakadžić, Sava

2016-01-01

Oxygen is delivered to brain tissue by a dense network of microvessels, which actively control cerebral blood flow (CBF) through vasodilation and contraction in response to changing levels of neural activity. Understanding these network-level processes is immediately relevant for (1) interpretation of functional Magnetic Resonance Imaging (fMRI) signals, and (2) investigation of neurological diseases in which a deterioration of neurovascular and neuro-metabolic physiology contributes to motor and cognitive decline. Experimental data on the structure, flow and oxygen levels of microvascular networks are needed, together with theoretical methods to integrate this information and predict physiologically relevant properties that are not directly measurable. Recent progress in optical imaging technologies for high-resolution in vivo measurement of the cerebral microvascular architecture, blood flow, and oxygenation enables construction of detailed computational models of cerebral hemodynamics and oxygen transport based on realistic three-dimensional microvascular networks. In this article, we review state-of-the-art optical microscopy technologies for quantitative in vivo imaging of cerebral microvascular structure, blood flow and oxygenation, and theoretical methods that utilize such data to generate spatially resolved models for blood flow and oxygen transport. These "bottom-up" models are essential for the understanding of the processes governing brain oxygenation in normal and disease states and for eventual translation of the lessons learned from animal studies to humans.

Central Hemodynamics and Oxygen Transport in Various Activation of Patients Operated On Under Extracorporeal Circulation

Directory of Open Access Journals (Sweden)

Ye. V. Dzybinskaya

2009-01-01

Full Text Available Objective: to study central hemodynamics, the determinants of myocardial oxygen balance, and the parameters of oxygen transport in various activation of patients after surgery under extracorporeal circulation. Subjects and methods. Thirty-four patients aged 57.8±2.5 years who had coronary heart disease were divided into 2 groups: 1 those with late activation (artificial ventilation time 157±9 min and 2 those with immediate activation (artificial ventilation time 33±6 min. Group 2 patients were, if required, given fentanyl, midazolam, or myorelaxants. Results. During activation, there were no intergroup differences in the mean levels of the major parameters of cardiac pump function, in the determinants of coronary blood flow (coronary perfusion gradients and myocardial oxygen demand (the product of heart rate by systolic blood pressure, and in the parameters of oxygen transport, including arterial lactatemia. After tracheal extubation, the left ventricular pump coefficient was increased considerably (up to 3.8±0.2 and 4.4±0.2 gm/mm Hg/m2 in Groups 1 and 2, respectively; p<0.05 with minimum inotropic support (dopamine and/or dobutamine being used at 2.7±0.3 and 2.4±0.3 mg/kg/min, respectively. In both groups, there were no close correlations between the indices of oxygen delivery and consumption at all stages of the study, which was indicative of no transport-dependent oxygen uptake. Conclusion. When the early activation protocol was followed up, the maximum acceleration of early activation, including that using specific antagonists of anesthetics, has no negative impact on central hemodynamics, the determinants of myocardial oxygen balance and transport in patients operated on under extracorporeal circulation. Key words: early activation, surgery under extracorporeal circulation, tracheal extubation in the operating-room, central hemodynamics, oxygen transport.

Correction of Oxygen Transport and Metabolic Disturbances in Acute Poisoning by Neurotropic Substances

Directory of Open Access Journals (Sweden)

G. A. Livanov

2007-01-01

Full Text Available Objective: to examine the capacities of pharmacological correction of impairments in oxygen-transporting systems and metabolic processes with perfluorane and cytoflavin in critically ill patients with acute intoxication with neurotropic poisons.Subjects and methods. Metabolic sequels of severe hypoxia, free radical processes, and endogenous intoxications were studied in 62 patients with the severest acute intoxication with neurotropic poisons.Results. The studies have established that hypoxia and metabolic changes lead to the development of endotoxicosis. Intensifying endotoxicosis in turn enhances hypoxic lesion. Thus, the major task of intensive care is to restore oxygen delivery and to diminish metabolic disturbances and endotoxicosis. Ways of correcting hypoxia and metabolic disturbances are considered in the severe forms of acute poisoning. 

Oxygen nonstoichiometry and transport properties of strontium substituted lanthanum cobaltite

DEFF Research Database (Denmark)

Søgaard, Martin; Hendriksen, Peter Vang; Mogensen, Mogens Bjerg

2006-01-01

Oxygen nonstoichiometry, structure and transport properties of the two compositions (La-0.6 Sr-0.4)(0.99)CoO3-delta (LSC40) and La0.85Sr0.15CoO3-delta (LSC15) were measured. It was found that the oxygen nonstoichiometry as a function of the temperature and oxygen partial pressure could be described...... using the itinerant electron model. The electrical conductivity, sigma, of the materials is high (sigma > 500 S cm(-1)) in the measured temperature range (650 - 1000 degrees C) and oxygen partial pressure range (0.209-10(-4) atm). At 900 degrees C the electrical conductivity is 1365 and 1491 S cm(-1......) in air for LSC40 and LSC15, respectively. A linear correlation between the electrical conductivity and the oxygen vacancy concentration was found for both samples. The mobility of the electron-holes was inversely proportional with the absolute temperature indicating a metallic type conductivity for LSC40...

Advanced Oxygen Systems for Aircraft (Systemes d’Oxygene Avances)

Science.gov (United States)

1996-04-01

Oxygen Generating System (NAOGS), SAM-TR-80-12, Brooks AFB TX 78235, 1980. 11. Horch TC, Miller RL, Bomar JB, Tedor JB, Holden RD, Ikels KG, and...sieve oxygen generation sys- tem. Data from Horch et al (15). cabin altitude. The minimum and maximum oxygen concen- tration lines depict the...an AV-8A Aircraft; Naval Air Test Center Report No. SY-136R-81, 1981. 15. Horch TC, Miller RL, Bomar JB Jr, Tedor JB, Holden RD, Ikels KG, and

Micromechanism of oxygen transport during initial stage oxidation in Si(100) surface: A ReaxFF molecular dynamics simulation study

International Nuclear Information System (INIS)

Sun, Yu; Liu, Yilun; Chen, Xuefeng; Zhai, Zhi; Xu, Fei; Liu, Yijun

2017-01-01

Highlights: • A competition mechanism between thermal actuation and compressive stress blocking was found for the oxygen transport. • At low temperature, a compressive stress was generated in the oxide layer which blocked oxygen transport into the deeper region. • O atoms gained larger possibility to go deeper inward as temperature increase. • The related film quality was well explained by the competition mechanism. - Abstract: The early stage oxidation in Si(100) surface has been investigated in this work by a reactive force field molecular dynamics (ReaxFF MD) simulation, manifesting that the oxygen transport acted as a dominant issue for initial oxidation process. Due to the oxidation, a compressive stress was generated in the oxide layer which blocked the oxygen transport perpendicular to the Si(100) surface and further prevented oxidation in the deeper layer. In contrast, thermal actuation was beneficial to the oxygen transport into deeper layer as temperature increases. Therefore, a competition mechanism was found for the oxygen transport during early stage oxidation in Si(100) surface. At room temperature, the oxygen transport was governed by the blocking effect of compressive stress, so a better quality oxide film with more uniform interface and more stoichiometric oxide structure was obtained. Indeed, the mechanism presented in this work is also applicable for other self-limiting oxidation (e.g. metal oxidation) and is helpful for the design of high-performance electronic devices.

Micromechanism of oxygen transport during initial stage oxidation in Si(100) surface: A ReaxFF molecular dynamics simulation study

Energy Technology Data Exchange (ETDEWEB)

Sun, Yu, E-mail: yu.sun@xjtu.edu.cn [State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Institute for Computational Mechanics and Its Applications, Northwestern Polytechnical University, Xi’an 710072 (China); Liu, Yilun [State Key Laboratory for Strength and Vibration of Mechanical Structures, School of Aerospace Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Chen, Xuefeng; Zhai, Zhi [State Key Laboratory for Manufacturing Systems Engineering, School of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Xu, Fei [Institute for Computational Mechanics and Its Applications, Northwestern Polytechnical University, Xi’an 710072 (China); Liu, Yijun [Institute for Computational Mechanics and Its Applications, Northwestern Polytechnical University, Xi’an 710072 (China); Mechanical Engineering, University of Cincinnati, Cincinnati, OH 45221-0072 (United States)

2017-06-01

Highlights: • A competition mechanism between thermal actuation and compressive stress blocking was found for the oxygen transport. • At low temperature, a compressive stress was generated in the oxide layer which blocked oxygen transport into the deeper region. • O atoms gained larger possibility to go deeper inward as temperature increase. • The related film quality was well explained by the competition mechanism. - Abstract: The early stage oxidation in Si(100) surface has been investigated in this work by a reactive force field molecular dynamics (ReaxFF MD) simulation, manifesting that the oxygen transport acted as a dominant issue for initial oxidation process. Due to the oxidation, a compressive stress was generated in the oxide layer which blocked the oxygen transport perpendicular to the Si(100) surface and further prevented oxidation in the deeper layer. In contrast, thermal actuation was beneficial to the oxygen transport into deeper layer as temperature increases. Therefore, a competition mechanism was found for the oxygen transport during early stage oxidation in Si(100) surface. At room temperature, the oxygen transport was governed by the blocking effect of compressive stress, so a better quality oxide film with more uniform interface and more stoichiometric oxide structure was obtained. Indeed, the mechanism presented in this work is also applicable for other self-limiting oxidation (e.g. metal oxidation) and is helpful for the design of high-performance electronic devices.

Dual phase oxygen transport membrane for efficient oxyfuel combustion

International Nuclear Information System (INIS)

Ramasamy, Madhumidha

2016-01-01

Oxygen transport membranes (OTMs) are attracting great interest for the separation of oxygen from air in an energy efficient way. A variety of solid oxide ceramic materials that possess mixed ionic and electronic conductivity (MIEC) are being investigated for efficient oxygen separation (Betz '10, Skinner '03). Unfortunately these materials do not exhibit high degradation stability under harsh ambient conditions such as flue gas containing CO_2, SO_x, H_2O and dust, pressure gradients and high temperatures that are typical in fossil fuel power plants. For this reason, dual phase composite membranes are developed to combine the best characteristics of different compounds to achieve high oxygen permeability and sufficient chemical and mechanical stability at elevated temperatures. In this thesis, the dual phase membrane Ce_0_._8Gd_0_._2O_2_-_δ - FeCo_2O_4 (CGO-FCO) was developed after systematic investigation of various combinations of ionic and electronic conductors. The phase distribution of the composite was investigated in detail using electron microscopes and this analysis revealed the phase interaction leading to grain boundary rock salt phase and formation of perovskite secondary phase. A systematic study explored the onset of phase interactions to form perovskite phase and the role of this unintended phase as pure electronic conductor was identified. Additionally optimization of conventional sintering process to eliminate spinel phase decomposition into rock salt was identified. An elaborate study on the absolute minimum electronic conductor requirement for efficient percolation network was carried out and its influence on oxygen flux value was measured. Oxygen permeation measurements in the temperature range of 600 C - 1000 C under partial pressure gradient provided by air and argon as feed and sweep gases are used to identify limiting transport processes. The dual phase membranes are much more prone to surface exchange limitations because of the limited

Enhanced safety margins during wet transport of irradiated fuel by catalytic recombination of radiolysis hydrogen and oxygen

International Nuclear Information System (INIS)

Spencer, J.T.; Bankhead, M.; Hodge, N.A.

2004-01-01

BNFL has developed and tested a new method for use in wet transport of irradiated fuel. The method uses a catalyst to recombine the hydrogen and oxygen produced from radiolysis. The catalyst is installed in the nitrogen ullage gas region. It has twin benefits as it eliminates a gas mixture that could, in principle, exceed the safe target levels set to ensure safety during Transport, and it also reduces overall gas pressure. Pure water radiolysis predictions, from experiment and theory, indicate very low levels of hydrogen and oxygen generation. BNFL's historic experience is that in some transport packages it is possible to produce higher levels of hydrogen and oxygen. This drives the need to improve on our existing ullage gas remediation technology. Our studies of the radiolysis science and our flask data suggest it is the interaction of the liquors and material surfaces that is giving rise to the enhanced levels of hydrogen and/or oxygen. This technical paper demonstrates the performance of the recombiner catalyst under normal and extreme conditions of transport. The paper will present experimental data that shows the recombiner catalyst working to manage the hydrogen and oxygen levels

Effects of Reactive Oxygen Species on Tubular Transport along the Nephron.

Science.gov (United States)

Gonzalez-Vicente, Agustin; Garvin, Jeffrey L

2017-03-23

Reactive oxygen species (ROS) are oxygen-containing molecules naturally occurring in both inorganic and biological chemical systems. Due to their high reactivity and potentially damaging effects to biomolecules, cells express a battery of enzymes to rapidly metabolize them to innocuous intermediaries. Initially, ROS were considered by biologists as dangerous byproducts of respiration capable of causing oxidative stress, a condition in which overproduction of ROS leads to a reduction in protective molecules and enzymes and consequent damage to lipids, proteins, and DNA. In fact, ROS are used by immune systems to kill virus and bacteria, causing inflammation and local tissue damage. Today, we know that the functions of ROS are not so limited, and that they also act as signaling molecules mediating processes as diverse as gene expression, mechanosensation, and epithelial transport. In the kidney, ROS such as nitric oxide (NO), superoxide (O₂ - ), and their derivative molecules hydrogen peroxide (H₂O₂) and peroxynitrite (ONO₂ - ) regulate solute and water reabsorption, which is vital to maintain electrolyte homeostasis and extracellular fluid volume. This article reviews the effects of NO, O₂ - , ONO₂ - , and H₂O₂ on water and electrolyte reabsorption in proximal tubules, thick ascending limbs, and collecting ducts, and the effects of NO and O₂ - in the macula densa on tubuloglomerular feedback.

Thermophysical properties and oxygen transport in (Thx,Pu1-x)O2.

Science.gov (United States)

Galvin, C O T; Cooper, M W D; Rushton, M J D; Grimes, R W

2016-10-31

Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Th x ,Pu 1-x )O 2 (0 ≤ x ≤ 1) between 300-3500 K. In particular, the superionic transition is investigated and viewed via the thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain compositions of (Th x ,Pu 1-x )O 2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen diffusivity for (Th x ,Pu 1-x )O 2 is explained in terms of lower oxygen defect formation enthalpies for (Th x ,Pu 1-x )O 2 than PuO 2 and ThO 2 , while links are drawn between the superionic transition temperature and oxygen Frenkel disorder.

OXYGEN TRANSPORT CERAMIC MEMBRANES

International Nuclear Information System (INIS)

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2001-01-01

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals. This project has the following 6 main tasks: Task 1--Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. Task 2--Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. Task 3--Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. Task 4--Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. Task 5--Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. Task 6--Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques

Dual phase oxygen transport membrane for efficient oxyfuel combustion

Energy Technology Data Exchange (ETDEWEB)

Ramasamy, Madhumidha

2016-07-01

Oxygen transport membranes (OTMs) are attracting great interest for the separation of oxygen from air in an energy efficient way. A variety of solid oxide ceramic materials that possess mixed ionic and electronic conductivity (MIEC) are being investigated for efficient oxygen separation (Betz '10, Skinner '03). Unfortunately these materials do not exhibit high degradation stability under harsh ambient conditions such as flue gas containing CO{sub 2}, SO{sub x}, H{sub 2}O and dust, pressure gradients and high temperatures that are typical in fossil fuel power plants. For this reason, dual phase composite membranes are developed to combine the best characteristics of different compounds to achieve high oxygen permeability and sufficient chemical and mechanical stability at elevated temperatures. In this thesis, the dual phase membrane Ce{sub 0.8}Gd{sub 0.2}O{sub 2-δ} - FeCo{sub 2}O{sub 4} (CGO-FCO) was developed after systematic investigation of various combinations of ionic and electronic conductors. The phase distribution of the composite was investigated in detail using electron microscopes and this analysis revealed the phase interaction leading to grain boundary rock salt phase and formation of perovskite secondary phase. A systematic study explored the onset of phase interactions to form perovskite phase and the role of this unintended phase as pure electronic conductor was identified. Additionally optimization of conventional sintering process to eliminate spinel phase decomposition into rock salt was identified. An elaborate study on the absolute minimum electronic conductor requirement for efficient percolation network was carried out and its influence on oxygen flux value was measured. Oxygen permeation measurements in the temperature range of 600 C - 1000 C under partial pressure gradient provided by air and argon as feed and sweep gases are used to identify limiting transport processes. The dual phase membranes are much more prone to surface

The obtaining and properties of asymmetric ion transport membrane for separating of oxygen from air

Science.gov (United States)

Solovieva, A. A.; Kulbakin, I. V.

2018-04-01

The bilayer oxygen-permeable membrane, consisting of a thin-film dense composite based on Co3O4 - 36 wt. % Bi2O3, and of a porous ceramic substrate of Co2SiO4, was synthesized and characterized. The way for obtaining of porous ceramic based on cobalt silicate was found, while the microstructure and the mechanical properties of porous ceramic were studied. Layered casting with post-pressing was used to cover the surface of porous support of Co2SiO4 by the Co3O4 - 36 wt. % Bi2O3 - based film. Transport properties of the asymmetric membrane have been studied, the kinetic features of oxygen transport have been established, and the characteristic thickness of the membrane has been estimated. The methods to prevent the high-temperature creep of ion transport membranes based on solid/molten oxides, which are the promising ones for obtaining of pure oxygen from air, are proposed and discussed.

Oxygen transport enhancement by functionalized magnetic nanoparticles (FMP) in bioprocesses

Science.gov (United States)

Ataide, Filipe Andre Prata

The enhancement of fluid properties, namely thermal conductivity and mass diffusivity for a wide range of applications, through the use of nanosized particles' suspensions has been gathering increasing interest in the scientific community. In previous studies, Olle et al. (2006) showed an enhancement in oxygen absorption to aqueous solutions of up to 6-fold through the use of functionalized nanosized magnetic particles with oleic acid coating. Krishnamurthy et al. (2006) showed a remarkable 26-fold enhancement in dye diffusion in water. These two publications are landmarks in mass transfer enhancement in chemical systems through the use of nanoparticles. The central goal of this Ph.D. thesis was to develop functionalized magnetic nanoparticles to enhance oxygen transport in bioprocesses. The experimental protocol for magnetic nanoparticles synthesis and purification adopted in this thesis is a modification of that reported by Olle et al. (2006). This is facilitated by employing twice the quantity of ammonia, added at a slower rate, and by filtering the final nanoparticle solution in a cross-flow filtration modulus against 55 volumes of distilled water. This modification in the protocol resulted in improved magnetic nanoparticles with measurably higher mass transfer enhancement. Magnetic nanoparticles with oleic acid and Hitenol-BC coating were screened for oxygen transfer enhancement, since these particles are relatively inexpensive and easy to synthesize. A glass 0.5-liter reactor was custom manufactured specifically for oxygen transport studies in magnetic nanoparticles suspensions. The reactor geometry, baffles and Rushton impeller are of standard dimensions. Mass transfer tests were conducted through the use of the sulphite oxidation method, applying iodometric back-titration. A 3-factor central composite circumscribed design (CCD) was adopted for design of experiments in order to generate sufficiently informative data to model the effect of magnetic

Oxygen transport and GeO2 stability during thermal oxidation of Ge

Science.gov (United States)

da Silva, S. R. M.; Rolim, G. K.; Soares, G. V.; Baumvol, I. J. R.; Krug, C.; Miotti, L.; Freire, F. L.; da Costa, M. E. H. M.; Radtke, C.

2012-05-01

Oxygen transport during thermal oxidation of Ge and desorption of the formed Ge oxide are investigated. Higher oxidation temperatures and lower oxygen pressures promote GeO desorption. An appreciable fraction of oxidized Ge desorbs during the growth of a GeO2 layer. The interplay between oxygen desorption and incorporation results in the exchange of O originally present in GeO2 by O from the gas phase throughout the oxide layer. This process is mediated by O vacancies generated at the GeO2/Ge interface. The formation of a substoichiometric oxide is shown to have direct relation with the GeO desorption.

Effect of selective blockade of oxygen consumption, glucose transport, and Ca2+ influx on thyroxine action in human mononuclear cells

DEFF Research Database (Denmark)

Kvetny, J; Matzen, L E

1990-01-01

The effect of selective blockade of cellular glucose transporters, Ca2+ influx, and mitochondrial oxygen consumption on thyroxine (T4)-stimulated oxygen consumption and glucose uptake was examined in human mononuclear blood cells. Blockade of glucose transporters by cytochalasin B (1 x 10(-5) mol....../L) and of Ca2+ influx by alprenolol (1 x 10(-5) mol/L) and verapamil (4 x 10(-4) mol/L) inhibited T4-activated glucose uptaken and reduced T4-stimulated oxygen consumption by 20%. Uncoupling of mitochondrial oxygen consumption by azide (1 x 10(-3) mol/L) inhibited T4-stimulated oxygen consumption, but had...... no effect on glucose uptake. We conclude that T4-stimulated glucose uptake in human mononuclear blood cells is dependent on intact glucose transporters and Ca2+ influx, but not on mitochondrial oxygen consumption. However, oxygen consumption is, in part, dependent on intact glucose uptake....

Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

KAUST Repository

Hong, Jongsup; Kirchen, Patrick; Ghoniem, Ahmed F.

2013-01-01

concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases

Oxygen transport properties estimation by classical trajectory–direct simulation Monte Carlo

Energy Technology Data Exchange (ETDEWEB)

Bruno, Domenico, E-mail: domenico.bruno@cnr.it [Istituto di Metodologie Inorganiche e dei Plasmi, Consiglio Nazionale delle Ricerche– Via G. Amendola 122, 70125 Bari (Italy); Frezzotti, Aldo, E-mail: aldo.frezzotti@polimi.it; Ghiroldi, Gian Pietro, E-mail: gpghiro@gmail.com [Dipartimento di Scienze e Tecnologie Aerospaziali, Politecnico di Milano–Via La Masa 34, 20156 Milano (Italy)

2015-05-15

Coupling direct simulation Monte Carlo (DSMC) simulations with classical trajectory calculations is a powerful tool to improve predictive capabilities of computational dilute gas dynamics. The considerable increase in computational effort outlined in early applications of the method can be compensated by running simulations on massively parallel computers. In particular, Graphics Processing Unit acceleration has been found quite effective in reducing computing time of classical trajectory (CT)-DSMC simulations. The aim of the present work is to study dilute molecular oxygen flows by modeling binary collisions, in the rigid rotor approximation, through an accurate Potential Energy Surface (PES), obtained by molecular beams scattering. The PES accuracy is assessed by calculating molecular oxygen transport properties by different equilibrium and non-equilibrium CT-DSMC based simulations that provide close values of the transport properties. Comparisons with available experimental data are presented and discussed in the temperature range 300–900 K, where vibrational degrees of freedom are expected to play a limited (but not always negligible) role.

A Low-Pressure Oxygen Storage System for Oxygen Supply in Low-Resource Settings.

Science.gov (United States)

Rassool, Roger P; Sobott, Bryn A; Peake, David J; Mutetire, Bagayana S; Moschovis, Peter P; Black, Jim Fp

2017-12-01

Widespread access to medical oxygen would reduce global pneumonia mortality. Oxygen concentrators are one proposed solution, but they have limitations, in particular vulnerability to electricity fluctuations and failure during blackouts. The low-pressure oxygen storage system addresses these limitations in low-resource settings. This study reports testing of the system in Melbourne, Australia, and nonclinical field testing in Mbarara, Uganda. The system included a power-conditioning unit, a standard oxygen concentrator, and an oxygen store. In Melbourne, pressure and flows were monitored during cycles of filling/emptying, with forced voltage fluctuations. The bladders were tested by increasing pressure until they ruptured. In Mbarara, the system was tested by accelerated cycles of filling/emptying and then run on grid power for 30 d. The low-pressure oxygen storage system performed well, including sustaining a pressure approximately twice the standard working pressure before rupture of the outer bag. Flow of 1.2 L/min was continuously maintained to a simulated patient during 30 d on grid power, despite power failures totaling 2.9% of the total time, with durations of 1-176 min (mean 36.2, median 18.5). The low-pressure oxygen storage system was robust and durable, with accelerated testing equivalent to at least 2 y of operation revealing no visible signs of imminent failure. Despite power cuts, the system continuously provided oxygen, equivalent to the treatment of one child, for 30 d under typical power conditions for sub-Saharan Africa. The low-pressure oxygen storage system is ready for clinical field trials. Copyright © 2017 by Daedalus Enterprises.

High temperature microcalorimetry. Study of metal-oxygen systems

International Nuclear Information System (INIS)

Tetot, R.; Picard, C.; Boureau, G.; Gerdanian, P.

1981-01-01

Determination of partial molar enthalpy in metal-oxygen systems at 1050 0 C. Three representative systems are studied: the solution of oxygen in titanium, the titanium-oxygen system and the uranium-oxygen system from UOsub(2.00) to UOsub(2.60) [fr

One-dimensional model of oxygen transport impedance accounting for convection perpendicular to the electrode

Energy Technology Data Exchange (ETDEWEB)

Mainka, J. [Laboratorio Nacional de Computacao Cientifica (LNCC), CMC 6097, Av. Getulio Vargas 333, 25651-075 Petropolis, RJ, Caixa Postal 95113 (Brazil); Maranzana, G.; Thomas, A.; Dillet, J.; Didierjean, S.; Lottin, O. [Laboratoire d' Energetique et de Mecanique Theorique et Appliquee (LEMTA), Universite de Lorraine, 2, avenue de la Foret de Haye, 54504 Vandoeuvre-les-Nancy (France); LEMTA, CNRS, 2, avenue de la Foret de Haye, 54504 Vandoeuvre-les-Nancy (France)

2012-10-15

A one-dimensional (1D) model of oxygen transport in the diffusion media of proton exchange membrane fuel cells (PEMFC) is presented, which considers convection perpendicular to the electrode in addition to diffusion. The resulting analytical expression of the convecto-diffusive impedance is obtained using a convection-diffusion equation instead of a diffusion equation in the case of classical Warburg impedance. The main hypothesis of the model is that the convective flux is generated by the evacuation of water produced at the cathode which flows through the porous media in vapor phase. This allows the expression of the convective flux velocity as a function of the current density and of the water transport coefficient {alpha} (the fraction of water being evacuated at the cathode outlet). The resulting 1D oxygen transport impedance neglects processes occurring in the direction parallel to the electrode that could have a significant impact on the cell impedance, like gas consumption or concentration oscillations induced by the measuring signal. However, it enables us to estimate the impact of convection perpendicular to the electrode on PEMFC impedance spectra and to determine in which conditions the approximation of a purely diffusive oxygen transport is valid. Experimental observations confirm the numerical results. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Thermophysical properties and oxygen transport in (Thx,Pu1−x)O2

Science.gov (United States)

Galvin, C. O. T.; Cooper, M. W. D.; Rushton, M. J. D.; Grimes, R. W.

2016-01-01

Using Molecular Dynamics, this paper investigates the thermophysical properties and oxygen transport of (Thx,Pu1−x)O2 (0 ≤ x ≤ 1) between 300–3500 K. In particular, the superionic transition is investigated and viewed via the thermal dependence of lattice parameter, linear thermal expansion coefficient, enthalpy and specific heat at constant pressure. Oxygen diffusivity and activation enthalpy are also investigated. Below the superionic temperature an increase of oxygen diffusivity for certain compositions of (Thx,Pu1−x)O2 compared to the pure end members is predicted. Oxygen defect formation enthalpies are also examined, as they underpin the superionic transition temperature and the increase in oxygen diffusivity. The increase in oxygen diffusivity for (Thx,Pu1−x)O2 is explained in terms of lower oxygen defect formation enthalpies for (Thx,Pu1−x)O2 than PuO2 and ThO2, while links are drawn between the superionic transition temperature and oxygen Frenkel disorder. PMID:27796314

Interactions between oxygen permeation and homogeneous-phase fuel conversion on the sweep side of an ion transport membrane

KAUST Repository

Hong, Jongsup

2013-02-01

The interactions between oxygen permeation and homogeneous fuel oxidation reactions on the sweep side of an ion transport membrane (ITM) are examined using a comprehensive model, which couples the dependency of the oxygen permeation rate on the membrane surface conditions and detailed chemistry and transport in the vicinity of the membrane. We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. Results show that increasing the sweep gas inlet temperature and fuel concentration enhances oxygen permeation substantially. This is accomplished through promoting oxidation reactions (oxygen consumption) and the transport of the products and reaction heat towards the membrane, which lowers the oxygen concentration and increases the gas temperature near the membrane. Faster reactions at higher fuel concentration and higher inlet gas temperature support substantial fuel conversion and lead to a higher oxygen permeation flux without the contribution of surface catalytic activity. Beyond a certain maximum in the fuel concentration, extensive heat loss to the membrane (and feed side) reduces the oxidation kinetic rates and limits oxygen permeation as the reaction front reaches the membrane. The sweep gas flow rate and channel height have moderate impacts on oxygen permeation and fuel conversion due to the residence time requirements for the chemical reactions and the location of the reaction zone relative to the membrane surface. © 2012 Elsevier B.V.

Two decades' experience with interfacility transport on extracorporeal membrane oxygenation.

Science.gov (United States)

Bryner, Benjamin; Cooley, Elaine; Copenhaver, William; Brierley, Kristin; Teman, Nicholas; Landis, Denise; Rycus, Peter; Hemmila, Mark; Napolitano, Lena M; Haft, Jonathan; Park, Pauline K; Bartlett, Robert H

2014-10-01

Interfacility transport of patients on extracorporeal membrane oxygenation (ECMO) has been performed in large numbers at only a few programs. Limited data are available on outcomes after ECMO transport to justify expanding or discontinuing these programs. This was a retrospective review of a 20-year, single-institution experience with interhospital ECMO transport as well as a systematic review of reports of transfers of patients on ECMO. Results of both were compared with historical data from the international registry of the Extracorporeal Life Support Organization (ELSO). Between 1990 and 2012, ECMO was used to facilitate transport of 221 patients to our institution, and 135 (62%) survived to discharge. Review of an additional 27 case series describing ECMO transport of 643 patients showed an overall survival of 61%. After stratifying by age and primary indication for ECMO, survival of transported patients was not significantly different compared with all ECMO patients in the ELSO registry, with the exception of pediatric patients treated for respiratory failure (transported patients in this category had higher survival than those in the ELSO registry). Interfacility transport on ECMO is feasible and can be accomplished safely in the critically ill. Survival of transported patients is comparable to age-matched and treatment-matched ECMO patients at large. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Solar Energy Systems for Lunar Oxygen Generation

Science.gov (United States)

Colozza, Anthony J.; Heller, Richard S.; Wong, Wayne A.; Hepp, Aloysius F.

2010-01-01

An evaluation of several solar concentrator-based systems for producing oxygen from lunar regolith was performed. The systems utilize a solar concentrator mirror to provide thermal energy for the oxygen production process. Thermal energy to power a Stirling heat engine and photovoltaics are compared for the production of electricity. The electricity produced is utilized to operate the equipment needed in the oxygen production process. The initial oxygen production method utilized in the analysis is hydrogen reduction of ilmenite. Utilizing this method of oxygen production a baseline system design was produced. This baseline system had an oxygen production rate of 0.6 kg/hr with a concentrator mirror size of 5 m. Variations were performed on the baseline design to show how changes in the system size and process (rate) affected the oxygen production rate. An evaluation of the power requirements for a carbothermal lunar regolith reduction reactor has also been conducted. The reactor had a total power requirement between 8,320 to 9,961 W when producing 1000 kg/year of oxygen. The solar concentrator used to provide the thermal power (over 82 percent of the total energy requirement) would have a diameter of less than 4 m.

Impacts of nitric oxide and superoxide on renal medullary oxygen transport and urine concentration

Science.gov (United States)

Edwards, Aurélie; Layton, Anita T.

2015-01-01

The goal of this study was to investigate the reciprocal interactions among oxygen (O2), nitric oxide (NO), and superoxide (O2−) and their effects on medullary oxygenation and urinary output. To accomplish that goal, we developed a detailed mathematical model of solute transport in the renal medulla of the rat kidney. The model represents the radial organization of the renal tubules and vessels, which centers around the vascular bundles in the outer medulla and around clusters of collecting ducts in the inner medulla. Model simulations yield significant radial gradients in interstitial fluid oxygen tension (Po2) and NO and O2− concentration in the OM and upper IM. In the deep inner medulla, interstitial fluid concentrations become much more homogeneous, as the radial organization of tubules and vessels is not distinguishable. The model further predicts that due to the nonlinear interactions among O2, NO, and O2−, the effects of NO and O2− on sodium transport, osmolality, and medullary oxygenation cannot be gleaned by considering each solute's effect in isolation. An additional simulation suggests that a sufficiently large reduction in tubular transport efficiency may be the key contributing factor, more so than oxidative stress alone, to hypertension-induced medullary hypoxia. Moreover, model predictions suggest that urine Po2 could serve as a biomarker for medullary hypoxia and a predictor of the risk for hospital-acquired acute kidney injury. PMID:25651567

Basic regulatory principles of Escherichia coli's electron transport chain for varying oxygen conditions.

Science.gov (United States)

Henkel, Sebastian G; Ter Beek, Alexander; Steinsiek, Sonja; Stagge, Stefan; Bettenbrock, Katja; de Mattos, M Joost Teixeira; Sauter, Thomas; Sawodny, Oliver; Ederer, Michael

2014-01-01

For adaptation between anaerobic, micro-aerobic and aerobic conditions Escherichia coli's metabolism and in particular its electron transport chain (ETC) is highly regulated. Although it is known that the global transcriptional regulators FNR and ArcA are involved in oxygen response it is unclear how they interplay in the regulation of ETC enzymes under micro-aerobic chemostat conditions. Also, there are diverse results which and how quinones (oxidised/reduced, ubiquinone/other quinones) are controlling the ArcBA two-component system. In the following a mathematical model of the E. coli ETC linked to basic modules for substrate uptake, fermentation product excretion and biomass formation is introduced. The kinetic modelling focusses on regulatory principles of the ETC for varying oxygen conditions in glucose-limited continuous cultures. The model is based on the balance of electron donation (glucose) and acceptance (oxygen or other acceptors). Also, it is able to account for different chemostat conditions due to changed substrate concentrations and dilution rates. The parameter identification process is divided into an estimation and a validation step based on previously published and new experimental data. The model shows that experimentally observed, qualitatively different behaviour of the ubiquinone redox state and the ArcA activity profile in the micro-aerobic range for different experimental conditions can emerge from a single network structure. The network structure features a strong feed-forward effect from the FNR regulatory system to the ArcBA regulatory system via a common control of the dehydrogenases of the ETC. The model supports the hypothesis that ubiquinone but not ubiquinol plays a key role in determining the activity of ArcBA in a glucose-limited chemostat at micro-aerobic conditions.

A cislunar transportation system fuelled by lunar resources

Science.gov (United States)

Sowers, G. F.

2016-11-01

A transportation system for a self sustaining economy in cislunar space is discussed. The system is based on liquid oxygen (LO2), liquid hydrogen (LH2) propulsion whose fuels are derived from ice mined at the polar regions of the Moon. The elements of the transportation system consist of the Advanced Cryogenic Evolved Stage (ACES) and the XEUS lander, both being developed by United Launch Alliance (ULA). The main propulsion elements and structures are common between ACES and XEUS. Both stages are fully reusable with refueling of their LO2/LH2 propellants. Utilization of lunar sourced propellants has the potential to dramatically lower the cost of transportation within the cislunar environs. These lower costs dramatically lower the barriers to entry of a number of promising cislunar based activities including space solar power. One early application of the architecture is providing lunar sourced propellant to refuel ACES for traditional spacecraft deployment missions. The business case for this application provides an economic framework for a potential lunar water mining operation.

Investigation of oxygen impurity transport using the O4+ visible spectral line in the Aditya tokamak

International Nuclear Information System (INIS)

Chowdhuri, M.B.; Ghosh, J.; Banerjee, S.; Dey, Ritu; Manchanda, R.; Kumar, Vinay; Vasu, P.; Patel, K.M.; Atrey, P.K.; Shankara Joisa, Y.; Rao, C.V.S.; Tanna, R.L.; Raju, D.; Chattopadhyay, P.K.; Jha, R.; Gupta, C.N.; Bhatt, S.B.; Saxena, Y.C.

2013-01-01

Intense visible lines from Be-like oxygen impurity are routinely observed in the Aditya tokamak. The spatial profile of brightness of a Be-like oxygen spectral line (2p3p 3 D 3 –2p3d 3 F 4 ) at 650.024 nm is used to investigate oxygen impurity transport in typical discharges of the Aditya tokamak. A 1.0 m multi-track spectrometer (Czerny–Turner) capable of simultaneous measurements from eight lines of sight is used to obtain the radial profile of brightness of O 4+ spectral emission. The emissivity profile of O 4+ spectral emission is obtained from the spatial profile of brightness using an Abel-like matrix inversion. The oxygen transport coefficients are determined by reproducing the experimentally measured emissivity profiles of O 4+ , using a one-dimensional empirical impurity transport code, STRAHL. Much higher values of the diffusion coefficient compared with the neo-classical values are observed in both the high magnetic field edge region (D inboard max ∼30 m 2 s -1 ) and the low magnetic field edge region (D outboard max ∼45 m 2 s -1 ) of typical Aditya ohmic plasmas, which seems to be due to fluctuation-induced transport. The diffusion coefficient at the limiter radius in the low-field (outboard) region is typically ∼ twice as high as that at the limiter radius in the high-field (inboard) region. (paper)

[Recent technical advances in portable oxygen delivery systems].

Science.gov (United States)

Machida, K; Kawabe, Y; Mori, M; Haga, T

1992-08-01

According to a Japanese national survey (June 30, 1990), the number of patients receiving home oxygen therapy (HOT) has been greater than 18,000 since March 1985, when HOT was first covered by health insurance. The oxygen concentrator, especially the molecular sieve type, is the most common method of delivery (more than 90%). In April 1988, the portable oxygen cylinder was acknowledged by health insurance, and the liquid oxygen supply system in April 1990. Three types of portable oxygen delivery systems are available; oxygen cyclinder, liquid oxygen system, and oxygen concentrator (membrane type), of which the oxygen cylinder is most commonly used. In our hospital, portable oxygen supply systems were used in 80% of 168 HOT cases in 1990, and the use of 400 L aluminum oxygen cylinders at a flow rate of 1-2 L/min has been most popular. There is an strong desire from patients for lighter portable oxygen supply system of longer duration. In 19 patients with chronic respiratory failure, we evaluated a newly designed demand oxygen delivery system (DODS), which weighs 2.4 kg including the DOD device (TER-20 Teijin), 1.1 L oxygen cylinder made of ultressor, nasal cannula, and carrier. Arterial blood gases at rest (room air) were PaO2 61.9 +/- 6.3 torr, PaCO2 63.8 +/- 9.4 torr and pH 7.40 +/- 0.04. A crossover trial was performed under three conditions; breathing room air with no weight, and pulse oxygen flow and continuous oxygen flow each carrying 2.4 kg of weight. Both 6 minute walking (E1) and walking on a slow speed treadmill (E2) were studied.(ABSTRACT TRUNCATED AT 250 WORDS)

A high-resolution non-invasive approach to quantify oxygen transport across the capillary fringe and within the underlying groundwater.

Science.gov (United States)

Haberer, Christina M; Rolle, Massimo; Liu, Sanheng; Cirpka, Olaf A; Grathwohl, Peter

2011-03-25

Oxygen transport across the capillary fringe is relevant for many biogeochemical processes. We present a non-invasive technique, based on optode technology, to measure high-resolution concentration profiles of oxygen across the unsaturated/saturated interface. By conducting a series of quasi two-dimensional flow-through laboratory experiments, we show that vertical hydrodynamic dispersion in the water-saturated part of the capillary fringe is the process limiting the mass transfer of oxygen. A number of experimental conditions were tested in order to investigate the influence of grain size and horizontal flow velocity on transverse vertical dispersion in the capillary fringe. In the same setup, analogous experiments were simultaneously carried out in the fully water-saturated zone, therefore allowing a direct comparison with oxygen transfer across the capillary fringe. The outcomes of the experiments under various conditions show that oxygen transport in the two zones of interest (i.e., the unsaturated/saturated interface and the saturated zone) is characterized by very similar transverse dispersion coefficients. An influence of the capillary fringe morphology on oxygen transport has not been observed. These results may be explained by the narrow grain size distribution used in the experiments, leading to a steep decline in water saturation at the unsaturated/saturated interface and to the absence of trapped gas in this transition zone. We also modeled flow (applying the van Genuchten and the Brooks-Corey relationships) and two-dimensional transport across the capillary fringe, obtaining simulated profiles of equivalent aqueous oxygen concentration that were in good agreement with the observations. Copyright © 2010 Elsevier B.V. All rights reserved.

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads.

Science.gov (United States)

Wang, Lin; Acosta, Miguel A; Leach, Jennie B; Carrier, Rebecca L

2013-04-21

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and oxygen insensitive Nile blue reference dye, and a poly-dimethylsiloxane (PDMS) shell rendering biocompatibility. Human intestinal epithelial Caco-2 cells were cultivated on a series of PDMS and type I collagen based substrates patterned with micro-well arrays for 3 or 7 days, and then brought into contact with oxygen sensing beads. Using an image analysis algorithm to convert florescence intensity of beads to partial oxygen pressure in the culture system, tens of microns-size oxygen sensing beads enabled the spatial measurement of local oxygen concentration in the microfabricated system. Results generally indicated lower oxygen level inside wells than on top of wells, and local oxygen level dependence on structural features of cell culture surfaces. Interestingly, chemical composition of cell culture substrates also appeared to affect oxygen level, with type-I collagen based cell culture systems having lower oxygen concentration compared to PDMS based cell culture systems. In general, results suggest that oxygen sensing beads can be utilized to achieve real-time and local monitoring of micro-environment oxygen level in 3D microfabricated cell culture systems.

Silicon Micropore-Based Parallel Plate Membrane Oxygenator.

Science.gov (United States)

Dharia, Ajay; Abada, Emily; Feinberg, Benjamin; Yeager, Torin; Moses, Willieford; Park, Jaehyun; Blaha, Charles; Wright, Nathan; Padilla, Benjamin; Roy, Shuvo

2018-02-01

Extracorporeal membrane oxygenation (ECMO) is a life support system that circulates the blood through an oxygenating system to temporarily (days to months) support heart or lung function during cardiopulmonary failure until organ recovery or replacement. Currently, the need for high levels of systemic anticoagulation and the risk for bleeding are main drawbacks of ECMO that can be addressed with a redesigned ECMO system. Our lab has developed an approach using microelectromechanical systems (MEMS) fabrication techniques to create novel gas exchange membranes consisting of a rigid silicon micropore membrane (SμM) support structure bonded to a thin film of gas-permeable polydimethylsiloxane (PDMS). This study details the fabrication process to create silicon membranes with highly uniform micropores that have a high level of pattern fidelity. The oxygen transport across these membranes was tested in a simple water-based bench-top set-up as well in a porcine in vivo model. It was determined that the mass transfer coefficient for the system using SµM-PDMS membranes was 3.03 ± 0.42 mL O 2 min -1 m -2 cm Hg -1 with pure water and 1.71 ± 1.03 mL O 2 min -1 m -2 cm Hg -1 with blood. An analytic model to predict gas transport was developed using data from the bench-top experiments and validated with in vivo testing. This was a proof of concept study showing adequate oxygen transport across a parallel plate SµM-PDMS membrane when used as a membrane oxygenator. This work establishes the tools and the equipoise to develop future generations of silicon micropore membrane oxygenators. © 2017 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Modeling of oxygen transport and cellular energetics explains observations on in vivo cardiac energy metabolism.

Directory of Open Access Journals (Sweden)

Daniel A Beard

2006-09-01

Full Text Available Observations on the relationship between cardiac work rate and the levels of energy metabolites adenosine triphosphate (ATP, adenosine diphosphate (ADP, and phosphocreatine (CrP have not been satisfactorily explained by theoretical models of cardiac energy metabolism. Specifically, the in vivo stability of ATP, ADP, and CrP levels in response to changes in work and respiratory rate has eluded explanation. Here a previously developed model of mitochondrial oxidative phosphorylation, which was developed based on data obtained from isolated cardiac mitochondria, is integrated with a spatially distributed model of oxygen transport in the myocardium to analyze data obtained from several laboratories over the past two decades. The model includes the components of the respiratory chain, the F0F1-ATPase, adenine nucleotide translocase, and the mitochondrial phosphate transporter at the mitochondrial level; adenylate kinase, creatine kinase, and ATP consumption in the cytoplasm; and oxygen transport between capillaries, interstitial fluid, and cardiomyocytes. The integrated model is able to reproduce experimental observations on ATP, ADP, CrP, and inorganic phosphate levels in canine hearts over a range of workload and during coronary hypoperfusion and predicts that cytoplasmic inorganic phosphate level is a key regulator of the rate of mitochondrial respiration at workloads for which the rate of cardiac oxygen consumption is less than or equal to approximately 12 mumol per minute per gram of tissue. At work rates corresponding to oxygen consumption higher than 12 mumol min(-1 g(-1, model predictions deviate from the experimental data, indicating that at high work rates, additional regulatory mechanisms that are not currently incorporated into the model may be important. Nevertheless, the integrated model explains metabolite levels observed at low to moderate workloads and the changes in metabolite levels and tissue oxygenation observed during graded

Determining the Source of Water Vapor in a Cerium Oxide Electrochemical Oxygen Separator to Achieve Aviator Grade Oxygen

Science.gov (United States)

Graf, John; Taylor, Dale; Martinez, James

2014-01-01

More than a metric ton of water is transported to the International Space Station (ISS) each year to provide breathing oxygen for the astronauts. Water is a safe and compact form of stored oxygen. The water is electrolyzed on ISS and ambient pressure oxygen is delivered to the cabin. A much smaller amount of oxygen is used each year in spacesuits to conduct Extra Vehicular Activities (EVAs). Space suits need high pressure (>1000 psia) high purity oxygen (must meet Aviator Breathing Oxygen "ABO" specifications, >99.5% O2). The water / water electrolysis system cannot directly provide high pressure, high purity oxygen, so oxygen for EVAs is transported to ISS in high pressure gas tanks. The tanks are relatively large and heavy, and the majority of the system launch weight is for the tanks and not the oxygen. Extracting high purity oxygen from cabin air and mechanically compressing the oxygen might enable on-board production of EVA grade oxygen using the existing water / water electrolysis system. This capability might also benefit human spaceflight missions, where oxygen for EVAs could be stored in the form of water, and converted into high pressure oxygen on-demand. Cerium oxide solid electrolyte-based ion transport membranes have been shown to separate oxygen from air, and a supported monolithic wafer form of the CeO2 electrolyte membrane has been shown to deliver oxygen at pressures greater than 300 psia. These supported monolithic wafers can withstand high pressure differentials even though the membrane is very thin, because the ion transport membrane is supported on both sides (Fig 1). The monolithic supported wafers have six distinct layers, each with matched coefficients of thermal expansion. The wafers are assembled into a cell stack which allows easy air flow across the wafers, uniform current distribution, and uniform current density (Fig 2). The oxygen separation is reported to be "infinitely selective" to oxygen [1] with reported purity of 99.99% [2

Evaluation of Losses Of Cold Energy of Cryogen Products in The Transport Systems

Science.gov (United States)

Uglanov, Dmitry; Sarmin, Dmitry; Tsapkova, Alexandra; Burdina, Yana

2017-12-01

At present, there are problems of energy saving in various areas of human life and in power complexes of industrial plants. One possible solution to the problem of increasing energy efficiency is the use of liquefied natural gas and its cold energy. Pipelines for fuel or gas supply in cryogen supply systems have different length depending on the mutual position of storage and cryogen consumption devices relatively to a start construction. Cryogen supply and transport systems include a lot of fittings of different assortment. Reservoirs can be installed on different elevation points. To reduce heat inleak and decrease cold energy of cryogen product different kinds of thermal insulation are used. Cryogen pipelines provide required operation conditions of storage and gasifying systems. The aim of the thermal calculation of cryogen transport and supply systems is to define the value of cryogen heat. In this paper it is shown values of cryogen temperature rise due to heat inleaks at cryogen’s transfer along transport systems for ethane, methane, oxygen and nitrogen were calculated. Heat inleaks also due to hydraulic losses were calculated. Specific losses of cold energy of cryogen product for laminar and turbulent flow were calculated. Correspondences of temperature rise, critical pipeline’s length and Reynolds number were defined for nitrogen, argon, methane and oxygen.

Oxygen transport in waterlogged soils, Part II. Diffusion coefficients

International Nuclear Information System (INIS)

Obando Moncayo, F.H.

2004-01-01

Several equations are available for Oxygen Transport in Waterlogged Soils and have been used for soils and plants. All of them are some form of first Fick's law as given by dQ = - DA(dc/dx)/dt. This equation illustrates some important aspects of aeration in waterlogged soils; first, D is a property of the medium and the gas, and is affected by temperature T. Likewise, the amount of diffusing substance dQ in dt is a direct function of the cross sectional area A and inversely proportional to the distance x. In fact, increasing the water content of air-dry soil, drastically decreases A and creates a further resistance for the flow of oxygen through water films around root plants, soil micro organisms and soil aggregates. The solid phase is also limiting the cross-section of surface of the free gaseous diffusion and the length and tortuosity of diffusion path in soil. In most of cases, soil gas porosity and tortuosity of soil voids are expressed in the equations of diffusion as a broad 'diffusion coefficient' (apparent coefficient diffusion). The process of soil respiration is complicated, involves many parameters, and is difficult to realistically quantify. With regard to the oxygen supply, it is convenient to distinguish macro and micro models, and hence, the flux of oxygen is assumed to have two steps. The first step is related to oxygen diffusion from the atmosphere and the air-filled porosity. The second step is related to the oxygen diffusion through water-films in and around plant roots, soil micro organisms and aggregates. Because of these models we obtain coefficients of macro or micro diffusion, rates of macro or micro diffusion, etc. In the macro diffusion process oxygen is transferred in the soil profile, mainly from the soil surface to a certain depth of the root zone, while micro diffusion deals with the flux over very short distances. Both processes, macro and micro diffusion are highly influenced by soil water content. Of course, if water is added to

Research and Development on Oxygen Transport Membranes at the Technical University of Denmark from Materials to Modules

DEFF Research Database (Denmark)

Kiebach, Wolff-Ragnar; Pirou, Stéven; Ovtar, Simona

2016-01-01

Oxygen transport membranes (OTMs) are inorganic, high temperature devices that have the potential to efficiently supply oxygen to combustion processes, for example for oxy-fired (biomass) gasification or in the cement and steel industry. This work reviews aspects of material selection, design...

Basic regulatory principles of Escherichia coli's electron transport chain for varying oxygen conditions

NARCIS (Netherlands)

Henkel, S.G.; Ter Beek, A.S.; Steinsiek, S.; Stagge, S.; Bettenbrock, K.; Teixeira De Mattos, M.J.; Sauter, T.; Sawodny, O.; Ederer, M.

2014-01-01

For adaptation between anaerobic, micro-aerobic and aerobic conditions Escherichia coli's metabolism and in particular its electron transport chain (ETC) is highly regulated. Although it is known that the global transcriptional regulators FNR and ArcA are involved in oxygen response it is unclear

Linking Arenicola marina irrigation behavior to oxygen transport and dynamics in sandy sediments

DEFF Research Database (Denmark)

Timmermann, Karen; Banta, Gary T.; Glud, Ronnie Nøhr

2007-01-01

In this study we examine how the irrigation behavior of the common lugworm Arenicola marina affects the distribution, transport and dynamics of oxygen in sediments using microelectrodes, planar optodes and diagenetic modeling. The irrigation pattern was characterized by a regular recurring period...... and only in rare situations with very high pumping rates (>200 ml h-1) and/or a narrow feeding funnel (water....... concentration in the burrow was high (80% air saturation) and oxygen was detected at distances up to 0.7 mm from the burrow wall. Volume specific oxygen consumption rates calculated from measured oxygen profiles were up to 4 times higher for sediments surrounding worm burrows as compared to surface sediments....... Model results indicated that oxygen consumption also was higher in the feeding pocket/funnel compared to the activity in surface sediments. An oxygen budget revealed that 49% of the oxygen pumped into the burrow during lugworm irrigation was consumed by the worm itself while 23% supported the diffusive...

Maternal and Fetal Recovery After Severe Respiratory Failure: A Case Report of Air Transportation of a Pregnant Woman on ECMO Using the CentriMag Transporter System.

Science.gov (United States)

Kaliyev, Rymbay; Kapyshev, Timur; Goncharov, Alex; Lesbekov, Timur; Pya, Yuri

2015-01-01

Use of extracorporeal membrane oxygenation (ECMO) for severe cardiopulmonary failure has increased because of improved outcomes. A specially designed ECMO transport system allows for safe transport of patients over long distances. We report a 28-year-old pregnant woman (26 weeks gestation) with acute respiratory distress syndrome in whom ECMO support was necessary for survival, and she was transported to another facility 1,155 km away with the aid of the portable ECMO system. Transport was uneventful, and the patient's condition remained stable. Acute respiratory distress syndrome improved gradually until the patient was discharged from the hospital with excellent maternal and fetal outcome.

[TRANSPORT OF OXYGEN DURING GEOMETRICAL RECONSTRUCTION OF THE LEFT VENTRICLE IN CONJUNCTION WITH CORONARY ARTERY BYPASS GRAFTING AND USING OF HIGH THORACIC EPIDURAL ANESTHESIA AS A MAJOR COMPONENT OF GENERAL ANAESTHESIA].

Science.gov (United States)

Zatevahina, M V; Farzutdinov, A F; Rahimov, A A; Makrushin, I M; Kvachantiradze, G Y

2015-01-01

The purpose of the study is to examine the perioperative dynamics of strategic blood oxygen transport indicators: delivery (DO2), consumption (VO2), the coefficient of oxygen uptake (CUO2) and their composition, as well as the dynamics of blood lactate indicators in patients with ischaemic heart disease (IHD) who underwent surgery under cardiopulmonary bypass with high thoracic epidural anaesthesia (HTEA) as the main component of anesthesia. Research was conducted in 30 patients with a critical degree of operational risk, during the correction of post-infarction heart aneurysmn using the V. Dor method in combination with coronary artery bypass grafting. The strategic blood oxygen transport indicators (delivery, consumption and the oxygen uptake coefficient) showed a statistically significant decrease compared to the physiological norm and to the initial data at two points of the research: the intubation of the trachea and during cardiopulmonary bypass. The system components of oxygen were influenced at problematic stages by the dynamics of SvO2 (increase), AVD (decrease), hemodilution withe fall of the HIb- in the process of JR in the persence of superficial hypothermia. The maintenance of optimal CA in the context of HTEA, combined with a balanced volemic load and a minimized cardiotonic support ensured the stabilisation of strategic blood oxygen transport indicators aithe postperfusion stage and during the immediate postoperative period The article is dedicated to the study of strategic blood oxygen transport indicators and their components during the operation of geometric reconstruc-tion of the left ventricle combined with coronary artery-bypass using cardiopulmonary bypass and with high thoracic epidural anesthesia as the main component of general anaesthesia. The analysis has covered the stagewise delivery dynamics, consumption and the oxygen uptake coefficient at II stages of the operation and of the immediate postoperative period. The study has ident (fled

Mars oxygen production system design

Science.gov (United States)

Cotton, Charles E.; Pillow, Linda K.; Perkinson, Robert C.; Brownlie, R. P.; Chwalowski, P.; Carmona, M. F.; Coopersmith, J. P.; Goff, J. C.; Harvey, L. L.; Kovacs, L. A.

1989-01-01

The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing.

The influence of lunar propellant production on the cost-effectiveness of cislunar transportation systems

Science.gov (United States)

Koelle, H. H.

1992-01-01

It is well known that propellants produced at the points of destination such as the Moon or Mars will help the economy of space transportation, particularly if round trips with a crew are involved. The construction and operation of a lunar base shortly after the turn of the century is one of the space programs under serious consideration at the present time. Space transportation is one of the major cost drivers. With present technology, if expendable launchers were employed, the specific transportation costs of one-way cargo flights would be approximately 10,000 dollars/kg (1985) at life-cycle cumulative 100,000 ton payload to the lunar surface. A fully reusable space transportation system using lunar oxygen and Earth-produced liquid hydrogen (LH2) would reduce the specific transportation costs by one order of magnitude to less than 1000 dollars/kg at the same payload volume. Another case of primary interest is the delivery of construction material and consumables from the lunar surface to the assembly site of space solar power plants in geostationary orbit (GEO). If such a system were technically and economically feasible, a cumulative payload of about 1 million tons or more would be required. At this level a space freighter system could deliver this material from Earth for about 300 dollars/kg (1985) to GEO. A lunar space transportation system using lunar oxygen and a fuel mixture of 50 percent Al and 50 percent LH2 (that has to come from Earth) could reduce the specific transportation costs to less than half, approximately 150 dollars/kg. If only lunar oxygen were available, these costs would come down to 200 dollars/kg. This analysis indicates a sizable reduction of the transportation burden on this type of mission. It should not be overlooked, however, that there are several uncertainties in such calculations. It is quite difficult at this point to calculate the cost of lunar-produced O and/or Al. This will be a function of production rate and life

Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems.

Science.gov (United States)

Blok, Chris; Jackson, Brian E; Guo, Xianfeng; de Visser, Pieter H B; Marcelis, Leo F M

2017-01-01

Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of water and nutrients in water surpass those in substrate, even though the transport of oxygen may be more complex. Transport rates can only limit growth when they are below a rate corresponding to maximum plant uptake. Our first objective was to compare Chrysanthemum growth performance for three water-based growing systems with different irrigation. We compared; multi-point irrigation into a pond (DeepFlow); one-point irrigation resulting in a thin film of running water (NutrientFlow) and multi-point irrigation as droplets through air (Aeroponic). Second objective was to compare press pots as propagation medium with nutrient solution as propagation medium. The comparison included DeepFlow water-rooted cuttings with either the stem 1 cm into the nutrient solution or with the stem 1 cm above the nutrient solution. Measurements included fresh weight, dry weight, length, water supply, nutrient supply, and oxygen levels. To account for differences in radiation sum received, crop performance was evaluated with Radiation Use Efficiency (RUE) expressed as dry weight over sum of Photosynthetically Active Radiation. The reference, DeepFlow with substrate-based propagation, showed the highest RUE, even while the oxygen supply provided by irrigation was potentially growth limiting. DeepFlow with water-based propagation showed 15-17% lower RUEs than the reference. NutrientFlow showed 8% lower RUE than the reference, in combination with potentially limiting irrigation supply of nutrients and oxygen. Aeroponic showed RUE levels similar to the reference and Aeroponic had non-limiting irrigation supply of water, nutrients, and oxygen. Water-based propagation affected the subsequent

Characterization of transport properties in uranium dioxide: the case of the oxygen auto-diffusion

International Nuclear Information System (INIS)

Fraczkiewicz, M.; Baldinozzi, G.

2008-01-01

Point defects in uranium dioxide which control the transport phenomena are still badly known. The aim of this work is to show how in carrying out several experimental techniques, it is possible to demonstrate both the existence and to determine the nature (charge and localization) of predominant defects responsible of the transport phenomena in a fluorite-type structure oxide. The oxygen diffusion in the uranium dioxide illustrates this. In the first part of this work, the accent is put on the electric properties of uranium dioxide and more particularly on the variation laws of the electric conductivity in terms of temperature, of oxygen potential and of the impurities amounts present in the material. These evolutions are connected to point and charged complex defects models and the pertinence of these models is discussed. Besides, it is shown how the electric conductivity measurements can allow to define oxygen potential domains in which the concentrations in electronic carriers are controlled. This characterization being made, it is shown that the determination of the oxygen intrinsic diffusion coefficient and particularly its dependence to the oxygen potential and to the amount of impurity, allows to determine the main defect responsible to the atomic diffusion as well as its nature and its charge. In the second part, the experimental techniques to determine the oxygen diffusion coefficient are presented: there are the isotopic exchange technique for introducing the tracer in the material, and two techniques to characterize the diffusion profiles (SIMS and NRA). Examples of preliminary results are given for mono and polycrystalline samples. At last, from this methodology on uranium dioxide, studies considered to quantify the thermal and physicochemical effects are presented. Experiments considered with the aim to characterize the radiation diffusion in uranium dioxide are presented too. (O.M.)

Modelling Ecosystem Dynamics of the Oxygen Minimum Zones in the Angola Gyre and the Northern Benguela Upwelling System.

Science.gov (United States)

Schmidt, M.; Eggert, A.

2016-02-01

The Angola Gyre and the Northern Benguela Upwelling System are two major oxygen minimum zones (OMZ) of different kind connected by the system of African Eastern Boundary Currents. We discuss results from a 3-dimensional coupled biogeochemical model covering both oxygen-deficient systems. The biogeochemical model component comprises trophic levels up to zooplankton. Physiological properties of organisms are parameterized from field data gained mainly in the course of the project "Geochemistry and Ecology of the Namibian Upwelling System" (GENUS). The challenge of the modelling effort is the different nature of both systems. The Angola Gyre, located in a "shadow zone" of the tropical Atlantic, has a low productivity and little ventilation, hence a long residence time of water masses. In the northern Benguela Upwelling System, trade winds drive an intermittent, but permanent nutrient supply into the euphotic zone which fuels a high coastal productivity, large particle export and high oxygen consumption from dissimilatory processes. In addition to the local processes, oxygen-deficient water formed in the Angola Gyre is one of the source water masses of the poleward undercurrent, which feeds oxygen depleted water into the Benguela system. In order to simulate the oxygen distribution in the Benguela system, both physical transport as well as local biological processes need to be carefully adjusted in the model. The focus of the analysis is on the time scale and the relative contribution of the different oxygen related processes to the oxygen budgets in both the oxygen minimum zones. Although these are very different in both the OMZ, the model is found as suitable to produce oxygen minimum zones comparable with observations in the Benguela and the Angola Gyre as well. Variability of the oxygen concentration in the Angola Gyre depends strongly on organismic oxygen consumption, whereas the variability of the oxygen concentration on the Namibian shelf is governed mostly by

Significance of myoglobin as an oxygen store and oxygen transporter in the intermittently perfused human heart: a model study.

Science.gov (United States)

Endeward, Volker; Gros, Gerolf; Jürgens, Klaus D

2010-07-01

The mechanisms by which the left ventricular wall escapes anoxia during the systolic phase of low blood perfusion are investigated, especially the role of myoglobin (Mb), which can (i) store oxygen and (ii) facilitate intracellular oxygen transport. The quantitative role of these two Mb functions is studied in the maximally working human heart. Because discrimination between Mb functions has not been achieved experimentally, we use a Krogh cylinder model here. At a heart rate of 200 beats/min and a 1:1 ratio of diastole/systole, the systole lasts for 150 ms. The basic model assumption is that, with mobile Mb, the oxygen stored in the end-diastolic left ventricle wall exactly meets the demand during the 150 ms of systolic cessation of blood flow. The coronary blood flow necessary to achieve this agrees with literature data. By considering Mb immobile or setting its concentration to zero, respectively, we find that, depending on Mb concentration, Mb-facilitated O(2) transport maintains O(2) supply to the left ventricle wall during 22-34 of the 150 ms, while Mb storage function accounts for a further 12-17 ms. When Mb is completely absent, anoxia begins to develop after 116-99 ms. While Mb plays no significant role during diastole, it supplies O(2) to the left ventricular wall for < or = 50 ms of the 150 ms systole, whereas capillary haemoglobin is responsible for approximately 80 ms. Slight increases in haemoglobin concentration, blood flow, or capillary density can compensate the absence of Mb, a finding which agrees well with the observations using Mb knockout mice.

Does recombinant human Epo increase exercise capacity by means other than augmenting oxygen transport?

DEFF Research Database (Denmark)

Lundby, C; Robach, P; Boushel, R

2008-01-01

This study was performed to test the hypothesis that administration of recombinant human erythropoietin (rHuEpo) in humans increases maximal oxygen consumption by augmenting the maximal oxygen carrying capacity of blood. Systemic and leg oxygen delivery and oxygen uptake were studied during...... before rHuEpo treatment). Blood buffer capacity remained unaffected by rHuEpo treatment and hemodilution. The augmented hematocrit did not compromise peak cardiac output. In summary, in healthy humans, rHuEpo increases maximal oxygen consumption due to augmented systemic and muscular peak oxygen delivery....

A high reliability oxygen deficiency monitoring system

International Nuclear Information System (INIS)

Parry, R.; Claborn, G.; Haas, A.; Landis, R.; Page, W.; Smith, J.

1993-05-01

The escalating use of cryogens at national laboratories in general and accelerators in particular, along with the increased emphasis placed on personnel safety, mandates the development and installation of oxygen monitoring systems to insure personnel safety in the event of a cryogenic leak. Numerous vendors offer oxygen deficiency monitoring systems but fail to provide important features and/or flexibility. This paper describes a unique oxygen monitoring system developed for the Magnet Test Laboratory (MTL) at the Superconducting Super Collider Laboratory (SSCL). Features include: high reliability, oxygen cell redundancy, sensor longevity, simple calibration, multiple trip points, offending sensor audio and visual indication, global alarms for building evacuation, local and remote analog readout, event and analog data logging, EMAIL event notification, phone line voice status system, and multi-drop communications network capability for reduced cable runs. Of particular importance is the distributed topology of the system which allows it to operate in a stand-alone configuration or to communicate with a host computer. This flexibility makes it ideal for small applications such as a small room containing a cryogenic dewar, as well as larger systems which monitor many offices and labs in several buildings

A high reliability oxygen deficiency monitoring system

International Nuclear Information System (INIS)

Parry, R.; Claborn, G.; Haas, A.; Landis, R.; Page, W.; Smith, J.

1993-01-01

The escalating use of cryogens at national laboratories in general and accelerators in particular, along with the increased emphasis placed on personnel safety, mandates the development and installation of oxygen monitoring systems to insure personnel safety in the event of a cryogenic leak. Numerous vendors offer oxygen deficiency monitoring systems but fail to provide important features and/or flexibility. This paper describes a unique oxygen monitoring system developed for the Magnet Test Laboratory (MTL) at the Superconducting Super Collider Laboratory (SSCL). Features include: high reliability, oxygen cell redundancy, sensor longevity, simple calibration, multiple trip points, offending sensor audio and visual indication, global alarms for building evacuation, local and remote analog readout, event and analog data logging, EMAIL event notification, phone line voice status system, and multi-drop communications network capability for reduced cable runs. Of particular importance is the distributed topology of the system which allows it to operate in a stand-alone configuration or to communicate with a host computer. This flexibility makes it ideal for small applications such as a small room containing a cryogenic dewar, as well as larger systems which monitor many offices and labs in several buildings

Influence of gemfibrozil on sulfate transport in human erythrocytes during the oxygenation-deoxygenation cycle

Czech Academy of Sciences Publication Activity Database

Tellone, E.; Ficarra, S.; Scatena, R.; Giardina, B.; Kotyk, Arnošt; Russo, A.; Colucci, D.; Bellocco, E.; Lagana, G.; Galtieri, A.

2008-01-01

Roč. 57, č. 4 (2008), s. 621-629 ISSN 0862-8408 R&D Projects: GA AV ČR(CZ) 1ET400110403 Institutional research plan: CEZ:AV0Z50110509 Keywords : gemfibrozil * sulfate transport * oxygenation-deoxygenation Subject RIV: CE - Biochemistry Impact factor: 1.653, year: 2008

Laminar oxy-fuel diffusion flame supported by an oxygen-permeable-ion-transport membrane

KAUST Repository

Hong, Jongsup

2013-03-01

A numerical model with detailed gas-phase chemistry and transport was used to predict homogeneous fuel conversion processes and to capture the important features (e.g., the location, temperature, thickness and structure of a flame) of laminar oxy-fuel diffusion flames stabilized on the sweep side of an oxygen permeable ion transport membrane (ITM). We assume that the membrane surface is not catalytic to hydrocarbon or syngas oxidation. It has been demonstrated that an ITM can be used for hydrocarbon conversion with enhanced reaction selectivity such as oxy-fuel combustion for carbon capture technologies and syngas production. Within an ITM unit, the oxidizer flow rate, i.e., the oxygen permeation flux, is not a pre-determined quantity, since it depends on the oxygen partial pressures on the feed and sweep sides and the membrane temperature. Instead, it is influenced by the oxidation reactions that are also dependent on the oxygen permeation rate, the initial conditions of the sweep gas, i.e., the fuel concentration, flow rate and temperature, and the diluent. In oxy-fuel combustion applications, the sweep side is fuel-diluted with CO2, and the entire unit is preheated to achieve a high oxygen permeation flux. This study focuses on the flame structure under these conditions and specifically on the chemical effect of CO2 dilution. Results show that, when the fuel diluent is CO2, a diffusion flame with a lower temperature and a larger thickness is established in the vicinity of the membrane, in comparison with the case in which N2 is used as a diluent. Enhanced OH-driven reactions and suppressed H radical chemistry result in the formation of products with larger CO and H2O and smaller H2 concentrations. Moreover, radical concentrations are reduced due to the high CO2 fraction in the sweep gas. CO2 dilution reduces CH3 formation and slows down the formation of soot precursors, C2H2 and C2H4. The flame location impacts the species diffusion and heat transfer from the

Reactive oxygen species and nitric oxide in plant mitochondria: origin and redundant regulatory systems.

Science.gov (United States)

Blokhina, Olga; Fagerstedt, Kurt V

2010-04-01

Plant mitochondria differ from their mammalian counterparts in many respects, which are due to the unique and variable surroundings of plant mitochondria. In green leaves, plant mitochondria are surrounded by ample respiratory substrates and abundant molecular oxygen, both resulting from active photosynthesis, while in roots and bulky rhizomes and fruit carbohydrates may be plenty, whereas oxygen levels are falling. Several enzymatic complexes in mitochondrial electron transport chain (ETC) are capable of reactive oxygen species (ROS) formation under physiological and pathological conditions. Inherently connected parameters such as the redox state of electron carriers in the ETC, ATP synthase activity and inner mitochondrial membrane potential, when affected by external stimuli, can give rise to ROS formation via complexes I and III, and by reverse electron transport (RET) from complex II. Superoxide radicals produced are quickly scavenged by superoxide dismutase (MnSOD), and the resulting H(2)O(2) is detoxified by peroxiredoxin-thioredoxin system or by the enzymes of ascorbate-glutathione cycle, found in the mitochondrial matrix. Arginine-dependent nitric oxide (NO)-releasing activity of enzymatic origin has been detected in plant mitochondria. The molecular identity of the enzyme is not clear but the involvement of mitochondria-localized enzymes responsible for arginine catabolism, arginase and ornithine aminotransferase has been shown in the regulation of NO efflux. Besides direct control by antioxidants, mitochondrial ROS production is tightly controlled by multiple redundant systems affecting inner membrane potential: NAD(P)H-dependent dehydrogenases, alternative oxidase (AOX), uncoupling proteins, ATP-sensitive K(+) channel and a number of matrix and intermembrane enzymes capable of direct electron donation to ETC. NO removal, on the other hand, takes place either by reactions with molecular oxygen or superoxide resulting in peroxynitrite, nitrite or nitrate

Nitric Oxide is Required for Homeostasis of Oxygen and Reactive Oxygen Species in Barley Roots under Aerobic Conditions

DEFF Research Database (Denmark)

Gupta, Kapuganti J; Hebelstrup, Kim; Kruger, Nicholas J

2014-01-01

Oxygen, the terminal electron acceptor for mitochondrial electron transport, is vital for plants because of its role in the production of ATP by oxidative phosphorylation. While photosynthetic oxygen production contributes to the oxygen supply in leaves, reducing the risk of oxygen limitation of ...... electron transport chain (Gupta et al., 2011). Thus, NO could influence oxygen consumption under normal aerobic conditions in roots, and it is this specific function that is assessed here.......Oxygen, the terminal electron acceptor for mitochondrial electron transport, is vital for plants because of its role in the production of ATP by oxidative phosphorylation. While photosynthetic oxygen production contributes to the oxygen supply in leaves, reducing the risk of oxygen limitation...

The Experimental Measurement of Local and Bulk Oxygen Transport Resistances in the Catalyst Layer of Proton Exchange Membrane Fuel Cells.

Science.gov (United States)

Wang, Chao; Cheng, Xiaojing; Lu, Jiabin; Shen, Shuiyun; Yan, Xiaohui; Yin, Jiewei; Wei, Guanghua; Zhang, Junliang

2017-12-07

Remarkable progress has been made in reducing the cathodic Pt loading of PEMFCs; however, a huge performance loss appears at high current densities, indicating the existence of a large oxygen transport resistance associated with the ultralow Pt loading catalyst layer. To reduce the Pt loading without sacrificing cell performance, it is essential to illuminate the oxygen transport mechanism in the catalyst layer. Toward this goal, an experimental approach to measure the oxygen transport resistance in catalyst layers is proposed and realized for the first time in this study. The measuring approach involves a dual-layer catalyst layer design, which consists of a dummy catalyst layer and a practical catalyst layer, followed by changing the thickness of dummy layer to respectively quantify the local and bulk resistances via limiting current measurements combined with linear extrapolation. The experimental results clearly reveal that the local resistance dominates the total resistance in the catalyst layer.

ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY

Directory of Open Access Journals (Sweden)

Ali Payıdar AKGÜNGÖR

2004-03-01

Full Text Available Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properties. Every transportation system has advantages and disadvantages over each other. Therefore, comprehensive plans for future periods have to be prepared and how the sources of the country should be reasonably distributed among transportation systems must be investigated. Also, transportation plans have to be prepared to get coordinated operations among transportation systems while great investments are instituted in the entire country. There is no doubt that it is possible with combined transportation instead of concentration on one transportation system. Transportation policies in Turkey should be questioned since the level of highway transportation usage reaches to 95 % and level of sea transportation usage drops to less than 1 % in spite of being surrounded with sea in three sides of our land. In this paper, transportation systems and transportation policies in Turkey are evaluated in general and problems are analysed. Proposals are presented for the solutions of these problems.

Surface oxygen vacancy and oxygen permeation flux limits of perovskite ion transport membranes

KAUST Repository

Hunt, Anton

2015-09-01

© 2015 Elsevier B.V. The mechanisms and quantitative models for how oxygen is separated from air using ion transport membranes (ITMs) are not well understood, largely due to the experimental complexity for determining surface exchange reactions at extreme temperatures (>800°C). This is especially true when fuels are present at the permeate surface. For both inert and reactive (fuels) operations, solid-state oxygen surface vacancies (δ) are ultimately responsible for driving the oxygen flux, JO2. In the inert case, the value of δ at either surface is a function of the local PO2 and temperature, whilst the magnitude of δ dictates both the JO2 and the inherent stability of the material. In this study values of δ are presented based on experimental measurements under inert (CO2) sweep: using a permeation flux model and local PO2 measurements, collected by means of a local gas-sampling probe in our large-scale reactor, we can determine δ directly. The ITM assessed was La0.9Ca0.1FeO3-δ (LCF); the relative resistances to JO2 were quantified using the pre-defined permeation flux model and local PO2 values. Across a temperature range from 825°C to 1056°C, δ was found to vary from 0.007 to 0.029 (<1%), safely within material stability limits, whilst the permeate surface exchange resistance dominates. An inert JO2 limit was identified owing to a maximum sweep surface δ, δmaxinert. The physical presence of δmaxinert is attributed to a rate limiting step shift from desorption to associative electron transfer steps on the sweep surface as PO2 is reduced. Permeate surface exchange limitations under non-reactive conditions suggest that reactive (fuel) operation is necessary to accelerate surface chemistry for future work, to reduce flux resistance and push δpast δmaxinert in a stable manner.

Oxygen Compatibility of Brass-Filled PTFE Compared to Commonly Used Fluorinated Polymers for Oxygen Systems

Science.gov (United States)

Herald, Stephen D.; Frisby, Paul M.; Davis, Samuel Eddie

2009-01-01

Safe and reliable seal materials for high-pressure oxygen systems sometimes appear to be extinct species when sought out by oxygen systems designers. Materials that seal well are easy to find, but these materials are typically incompatible with oxygen, especially in cryogenic liquid form. This incompatibility can result in seals that leak, or much worse, seals that easily ignite and burn during use. Materials that are compatible with oxygen are easy to find, such as the long list of compatible metals, but these metallic materials are limiting as seal materials. A material that seals well and is oxygen compatible has been the big game in the designer's safari. Scientists at the Materials Combustion Research Facility (MCRF), part of NASA/Marshall Space Flight Center (MSFC), are constantly searching for better materials and processes to improve the safety of oxygen systems. One focus of this effort is improving the characteristics of polymers used in the presence of an oxygen enriched environment. Very few systems can be built which contain no polymeric materials; therefore, materials which have good impact resistance, low heat of combustion, high auto-ignition temperature and that maintain good mechanical properties are essential. The scientists and engineers at the Materials Combustion Research Facility, in cooperation with seal suppliers, are currently testing a new formulation of polytetrafluoroethylene (PTFE) with Brass filler. This Brass-filled PTFE is showing great promise as a seal and seat material for high pressure oxygen systems. Early research has demonstrated very encouraging results, which could rank this material as one of the best fluorinated polymers ever tested. This paper will compare the data obtained for Brass-filled PTFE with other fluorinated polymers, such as TFE-Teflon (PTFE) , Kel-F 81, Viton A, Viton A-500, Fluorel , and Algoflon . A similar metal filled fluorinated polymer, Salox-M , was tested in comparison to Brass-filled PTFE to

Acclimatory responses of the Daphnia pulex proteome to environmental changes. I. Chronic exposure to hypoxia affects the oxygen transport system and carbohydrate metabolism

Directory of Open Access Journals (Sweden)

Madlung Johannes

2009-04-01

Full Text Available Abstract Background Freshwater planktonic crustaceans of the genus Daphnia show a remarkable plasticity to cope with environmental changes in oxygen concentration and temperature. One of the key proteins of adaptive gene control in Daphnia pulex under hypoxia is hemoglobin (Hb, which increases in hemolymph concentration by an order of magnitude and shows an enhanced oxygen affinity due to changes in subunit composition. To explore the full spectrum of adaptive protein expression in response to low-oxygen conditions, two-dimensional gel electrophoresis and mass spectrometry were used to analyze the proteome composition of animals acclimated to normoxia (oxygen partial pressure [Po2]: 20 kPa and hypoxia (Po2: 3 kPa, respectively. Results The comparative proteome analysis showed an up-regulation of more than 50 protein spots under hypoxia. Identification of a major share of these spots revealed acclimatory changes for Hb, glycolytic enzymes (enolase, and enzymes involved in the degradation of storage and structural carbohydrates (e.g. cellubiohydrolase. Proteolytic enzymes remained constitutively expressed on a high level. Conclusion Acclimatory adjustments of the D. pulex proteome to hypoxia included a strong induction of Hb and carbohydrate-degrading enzymes. The scenario of adaptive protein expression under environmental hypoxia can be interpreted as a process to improve oxygen transport and carbohydrate provision for the maintenance of ATP production, even during short episodes of tissue hypoxia requiring support from anaerobic metabolism.

Transportation System Requirements Document

International Nuclear Information System (INIS)

1993-09-01

This Transportation System Requirements Document (Trans-SRD) describes the functions to be performed by and the technical requirements for the Transportation System to transport spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from Purchaser and Producer sites to a Civilian Radioactive Waste Management System (CRWMS) site, and between CRWMS sites. The purpose of this document is to define the system-level requirements for Transportation consistent with the CRWMS Requirement Document (CRD). These requirements include design and operations requirements to the extent they impact on the development of the physical segments of Transportation. The document also presents an overall description of Transportation, its functions, its segments, and the requirements allocated to the segments and the system-level interfaces with Transportation. The interface identification and description are published in the CRWMS Interface Specification

A compartment model of alveolar-capillary oxygen diffusion with ventilation-perfusion gradient and dynamics of air transport through the respiratory tract.

Science.gov (United States)

Jaworski, Jacek; Redlarski, Grzegorz

2014-08-01

This paper presents a model of alveolar-capillary oxygen diffusion with dynamics of air transport through the respiratory tract. For this purpose electrical model representing the respiratory tract mechanics and differential equations representing oxygen membrane diffusion are combined. Relevant thermodynamic relations describing the mass of oxygen transported into the human body are proposed as the connection between these models, as well as the influence of ventilation-perfusion mismatch on the oxygen diffusion. The model is verified based on simulation results of varying exercise intensities and statistical calculations of the results obtained during various clinical trials. The benefit of the approach proposed is its application in simulation-based research aimed to generate quantitative data of normal and pathological conditions. Based on the model presented, taking into account many essential physiological processes and air transport dynamics, comprehensive and combined studies of the respiratory efficiency can be performed. The impact of physical exercise, precise changes in respiratory tract mechanics and alterations in breathing pattern can be analyzed together with the impact of various changes in alveolar-capillary oxygen diffusion. This may be useful in simulation of effects of many severe medical conditions and increased activity level. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of advanced propulsion options for the next manned transportation system: Propulsion evolution study

Science.gov (United States)

Spears, L. T.; Kramer, R. D.

1990-01-01

The objectives were to examine launch vehicle applications and propulsion requirements for potential future manned space transportation systems and to support planning toward the evolution of Space Shuttle Main Engine (SSME) and Space Transportation Main Engine (STME) engines beyond their current or initial launch vehicle applications. As a basis for examinations of potential future manned launch vehicle applications, we used three classes of manned space transportation concepts currently under study: Space Transportation System Evolution, Personal Launch System (PLS), and Advanced Manned Launch System (AMLS). Tasks included studies of launch vehicle applications and requirements for hydrogen-oxygen rocket engines; the development of suggestions for STME engine evolution beyond the mid-1990's; the development of suggestions for STME evolution beyond the Advanced Launch System (ALS) application; the study of booster propulsion options, including LOX-Hydrocarbon options; the analysis of the prospects and requirements for utilization of a single engine configuration over the full range of vehicle applications, including manned vehicles plus ALS and Shuttle C; and a brief review of on-going and planned LOX-Hydrogen propulsion technology activities.

Sorbent-based Oxygen Production for Energy Systems

Energy Technology Data Exchange (ETDEWEB)

Sethi, Vijay [Western Research Inst. (WRI), Laramie, WY (United States)

2017-01-31

Project DE-FE0024075 deals with the development of a moderate-temperature sorbent-based oxygen production technology. Sorbent-based oxygen production process utilizes oxygen-storage properties of Perovskites to (1) adsorb oxygen from air in a solid sorbent, and (2) release the adsorbed oxygen into a sweep gas such as CO₂ and/or steam for gasification systems or recycled flue gas for oxy-combustion systems. Pure oxygen can be produced by the use of vacuum instead of a sweep gas to affect the pressure swing. By developing more efficient and stable, higher sorption capacity, newer class of materials operating at moderate temperatures this process represents a major advancement in air separation technology. Newly developed perovskite ceramic sorbent materials with order-disorder transition have a higher O₂ adsorption capacity, potentially 200 °C lower operating temperatures, and up to two orders of magnitude faster desorption rates than those used in earlier development efforts. The performance advancements afforded by the new materials lead to substantial savings in capital investment and operational costs. Cost of producing oxygen using sorbents could be as much as 26% lower than VPSA and about 13% lower than a large cryogenic air separation unit. Cost advantage against large cryogenic separation is limited because sorbent-based separation numbers up sorbent modules for achieving the larger capacity.

Analysis of the clinical backgrounds of patients who developed respiratory acidosis under high-flow oxygen therapy during emergency transport.

Science.gov (United States)

Ogino, Hirokazu; Nishimura, Naoki; Yamano, Yasuhiko; Ishikawa, Genta; Tomishima, Yutaka; Jinta, Torahiko; Takahashi, Osamu; Chohnabayashi, Naohiko

2016-01-01

High-flow oxygen is often administered to patients during emergency transport and can sometimes cause respiratory acidosis with disturbed consciousness, thereby necessitating mechanical ventilation. Although oxygen titration in chronic obstructive pulmonary disease patients during emergency transport reduces mortality rates, the clinical risk factors for respiratory acidosis in emergency settings are not fully understood. Therefore, we analyzed the clinical backgrounds of patients who developed respiratory acidosis during pre-hospital transport. This was a retrospective study of patients who arrived at our hospital by emergency transport in 2010 who received high-flow oxygen while in transit. Respiratory acidosis was defined by the following arterial blood gas readings: pH, ≤7.35; PaCO 2 , ≥45 mmHg; and HCO 3 - , ≥24 mmol/L. The risk factors were identified using multivariable logistic regression analysis. In 765 study patients, 66 patients showed respiratory acidosis. The following risk factors for respiratory acidosis were identified: age, ≥65 years (odds ratio [OR] 1.4; 95% confidence interval [CI], 0.7-2.8); transportation time, ≥10 min (OR 2.0; 95% CI, 1.1-3.7); three digits on the Japan Coma Scale (OR 3.1; 95% CI, 1.7-5.8); percutaneous oxygen saturation, ≤90% (OR 1.6; 95% CI, 0.8-3.0); tuberculosis (OR 4.5; 95% CI, 1.4-15.1); asthma (OR 1.8; 95% CI, 0.6-5.3); pneumonia (OR 1.5; 95% CI, 0.7-3.1); and lung cancer (OR 3.9; 95% CI, 1.5-10.1). These underlying diseases as risk factors included both comorbid diseases and past medical conditions. The factors identified may contribute to the development of respiratory acidosis. Further studies on preventing respiratory acidosis will improve the quality of emergency medical care.

A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs.

Directory of Open Access Journals (Sweden)

Folco eGiomi

2013-05-01

Full Text Available Heat tolerance in aquatic ectotherms is constrained by a mismatch, occurring at high temperatures, between oxygen delivery and demand which compromises the maintenance of aerobic scope. The present study analyses how the wide thermal tolerance range of an eurythermal model species, the green crab Carcinus maenas is supported and limited by its ability to sustain efficient oxygen transport to tissues. Similar to other eurytherms, C. maenas sustains naturally occurring acute warming events through the integrated response of circulatory and respiratory systems. The response of C. maenas to warming is characterized by two phases. During initial warming, oxygen consumption and heart rate increase while stroke volume and haemolymph oxygen partial pressures decrease. During further warming, dissolved oxygen levels in the venous compartment decrease below the threshold of full haemocyanin oxygen saturation. The progressive release of haemocyanin bound oxygen with further warming follows an exponential pattern, thereby saving energy in oxygen transport and causing an associated leveling off of metabolic rate. According to the concept of oxygen and capacity limited thermal tolerance, this indicates that the thermal tolerance window is widened by the increasing contribution of haemocyanin oxygen transport and associated energy savings in cardiocirculation. Haemocyanin bound oxygen sustains cardiac performance to cover the temperature range experienced by C. maenas in the field. To our knowledge this is the first study providing evidence of a relationship between thermal tolerance and blood (haemolymph oxygen transport in eurythermal invertebrates.

A role for haemolymph oxygen capacity in heat tolerance of eurythermal crabs.

Science.gov (United States)

Giomi, Folco; Pörtner, Hans-Otto

2013-01-01

Heat tolerance in aquatic ectotherms is constrained by a mismatch, occurring at high temperatures, between oxygen delivery and demand which compromises the maintenance of aerobic scope. The present study analyses how the wide thermal tolerance range of an eurythermal model species, the green crab Carcinus maenas is supported and limited by its ability to sustain efficient oxygen transport to tissues. Similar to other eurytherms, C. maenas sustains naturally occurring acute warming events through the integrated response of circulatory and respiratory systems. The response of C. maenas to warming can be characterized by two phases. During initial warming, oxygen consumption and heart rate increase, while stroke volume and haemolymph oxygen partial pressure decrease. During further warming, dissolved oxygen levels in the venous compartment decrease below the threshold of full haemocyanin oxygen saturation. The progressive release of haemocyanin bound oxygen with further warming follows an exponential pattern, thereby saving energy in oxygen transport and causing an associated leveling off of metabolic rate. According to the concept of oxygen and capacity limited thermal tolerance (OCLTT), this indicates that the thermal tolerance window is widened by the increasing contribution of haemocyanin oxygen transport and associated energy savings in cardiocirculation. Haemocyanin bound oxygen sustains cardiac performance to cover the temperature range experienced by C. maenas in the field. To our knowledge this is the first study providing evidence of a relationship between thermal tolerance and blood (haemolymph) oxygen transport in a eurythermal invertebrate.

The vanadium/oxygen system in the analysis of sodium for oxygen

International Nuclear Information System (INIS)

Walker, J.A.J.; Price, W.B.

1981-05-01

An investigation of the V-O-Na system at 1023 K is described for oxygen in sodium contents of 5 to 25 ppm. Electron spectroscopy combined with depth profiling is used to determine the vanadium/oxygen ratios inwards from the surface of vanadium foil and these ratios are compared with theoretical predictions. The validity of the vanadium wire technique as an analytical method is examined and a model for the vanadium oxidation is suggested. (author)

Relations between oxygen and hydrogen generated by radiolysis in the systems of a CANDU 600

International Nuclear Information System (INIS)

Romano, Christian; Chocron, Mauricio; Urrutia, Guillermo

1999-01-01

The water that constitutes the coolant of the primary heat transport system, the moderator and the liquid control zones, decomposed under radiation producing as stable products oxygen, hydrogen and hydrogen peroxide throughout a complex mechanisms of radiolysis that involves ions and free radicals. These compound formed in different proportions alters the chemical control established for each system which purpose is to minimize the corrosion of the structural materials. In the present paper have been presented results of the modelling of the mentioned processes and it has been found that in the absence of a vapor phase, a relatively low concentration of hydrogen added to the water would be sufficient to control the formation of oxygen and hydrogen peroxide. The last species however, would remain in relatively high values inside a coolant fuel channel in the reactor core. (author)

Kinetic of the Oxygen Control System (OCS) for stagnant lead-bismuth systems

International Nuclear Information System (INIS)

Lefhalm, C.H.; Knebel, J.U.; Mack, K.J.

2001-09-01

Within the framework of the HGF strategy fund project 99/16 ''Thermalhydraulic and Material Specific Investigations into the Realization of an accelerator driven system (ADS) to Transmute Minor Actinides'' at the institute for nuclear and energy technology (IKET) investigations on the cooling of thermally high-loaded surfaces with liquid lead bismuth (Pb-Bi) are carried out. To operate a Pb-Bi loop safety, for example in order to cool a spallation target or a blanket of an accelerator driven system (ADS), the control of the oxygen concentration within the liquid metal is an inalienable prerequisite to prevent or minimize corrosion at the structure material. In this report the kinetic behaviour of the oxygen control system (OCS), which was developed at Forschungszentrum Karlsruhe, is examined. The OCS controls the chemical potential of oxygen in the liquid metal by regulating the oxygen content in the gas phase which flows over the free surface of the liquid metal. In this work the experimental facility KOCOS (kinetics of oxygen control system) in the karlsruhe lead laboratory (KALLA) was built. A physical diffusion model was utilised and extended to describe the exchange of oxygen between the gas and the liquid metal. The theoretical calculations are in very good agreement to the experimental findings. The OCS allows to control reversibly the oxygen concentration in the liquid metal. According to the observed kinetics of the process one can extrapolate that the control of large volumes, as they are necessary to operate an ADS demonstrator, is possible. Therefore, further experiments in liquid metal loop systems are suggested. (orig.)

Production of an accelerated oxygen-14 beam

CERN Document Server

Powell, J; Cerny, J

2003-01-01

BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was carbon-11 and beams of intensity more than 10 sup 8 ions/s have been utilized for experiments. Development of oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 s and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has bee...

Hydrogenation and hydrodeoxygenation of biomass-derived oxygenates to liquid alkanes for transportation fuels.

Science.gov (United States)

Sun, Shaohui; Yang, Ruishu; Wang, Xin; Yan, Shaokang

2018-04-01

An attractive approach for the production of transportation fuels from renewable biomass resources is to convert oxygenates into alkanes. In this paper, C 5 -C 20 alkanes formed via the hydrogenation and hydrodeoxygenation of the oligomers of furfuryl alcohol(FA) can be used as gasoline, diesel and jet fuel fraction. The first step of the process is the oligomers of FA convert into hydrogenated products over Raney Ni catalyst in a batch reactor. The second step of the process converts hydrogenated products to alkanes via hydrodeoxygenation over different bi-functional catalysts include hydrogenation and acidic deoxidization active sites. After this process, the oxygen content decreased from 22.1 wt% in the oligomers of FA to 0.58 wt% in the hydrodeoxygenation products.

Production of an accelerated oxygen-14 beam

International Nuclear Information System (INIS)

Powell, J.; O'Neil, J.P.; Cerny, Joseph

2003-01-01

BEARS is an ongoing project to provide a light-ion radioactive-beam capability at the 88-Inch Cyclotron at LBNL. Light radioactive isotopes are produced at a 10 MeV proton medical cyclotron, transported 350 m via a high-speed gas transport capillary, cryogenically separated, and injected into the 88-Inch Cyclotron's ion source. The first radioactive beam successfully accelerated was carbon-11 and beams of intensity more than 10 8 ions/s have been utilized for experiments. Development of oxygen-14 as the second BEARS beam presented considerable technical challenges, both due to its short half-life of 71 s and the radiation chemistry of oxygen in the target. The usual techniques developed for medical uses of oxygen-15 involve the addition of significant amounts of carrier oxygen, something that would overload the ion source. As a solution, oxygen-14 is produced as water in a carrier-free form, and is chemically converted in two steps to carbon dioxide, a form readily usable by the BEARS. This system has been built and is operational, and initial tests of accelerating an oxygen-14 beam have been performed

Membrane transporters mediating root signalling and adaptive responses to oxygen deprivation and soil flooding.

Science.gov (United States)

Shabala, Sergey; Shabala, Lana; Barcelo, Juan; Poschenrieder, Charlotte

2014-10-01

This review provides a comprehensive assessment of a previously unexplored topic: elucidating the role that plasma- and organelle-based membrane transporters play in plant-adaptive responses to flooding. We show that energy availability and metabolic shifts under hypoxia and anoxia are critical in regulating membrane-transport activity. We illustrate the high tissue and time dependence of this regulation, reveal the molecular identity of transporters involved and discuss the modes of their regulation. We show that both reduced oxygen availability and accumulation of transition metals in flooded roots result in a reduction in the cytosolic K(+) pool, ultimately determining the cell's fate and transition to programmed cell death (PCD). This process can be strongly affected by hypoxia-induced changes in the amino acid pool profile and, specifically, ϒ-amino butyric acid (GABA) accumulation. It is suggested that GABA plays an important regulatory role, allowing plants to proceed with H2 O2 signalling to activate a cascade of genes that mediate plant adaptation to flooding while at the same time, preventing the cell from entering a 'suicide program'. We conclude that progress in crop breeding for flooding tolerance can only be achieved by pyramiding the numerous physiological traits that confer efficient energy maintenance, cytosolic ion homeostasis, and reactive oxygen species (ROS) control and detoxification. © 2014 John Wiley & Sons Ltd.

Intelligent Transport Systems in the Management of Road Transportation

Science.gov (United States)

Kalupová, Blanka; Hlavoň, Ivan

2016-11-01

Extension of European Union causes increase of free transfer of people and goods. At the same time they raised the problems associated with the transport, e.g. congestion and related accidents on roads, air traffic delays and more. To increase the efficiency and safety of transport, the European Commission supports the introduction of intelligent transport systems and services in all transport sectors. Implementation of intelligent transport systems and services in the road transport reduces accident frequency, increases the capacity of existing infrastructure and reduces congestions. Use of toll systems provides resources needed for the construction and operation of a new road network, improves public transport, cycling transport and walking transport, and also their multimodal integration with individual car transport.

Transportation System Concept of Operations

Energy Technology Data Exchange (ETDEWEB)

N. Slater-Thompson

2006-08-16

The Nuclear Waste Policy Act of 1982 (NWPA), as amended, authorized the DOE to develop and manage a Federal system for the disposal of SNF and HLW. OCRWM was created to manage acceptance and disposal of SNF and HLW in a manner that protects public health, safety, and the environment; enhances national and energy security; and merits public confidence. This responsibility includes managing the transportation of SNF and HLW from origin sites to the Repository for disposal. The Transportation System Concept of Operations is the core high-level OCRWM document written to describe the Transportation System integrated design and present the vision, mission, and goals for Transportation System operations. By defining the functions, processes, and critical interfaces of this system early in the system development phase, programmatic risks are minimized, system costs are contained, and system operations are better managed, safer, and more secure. This document also facilitates discussions and understanding among parties responsible for the design, development, and operation of the Transportation System. Such understanding is important for the timely development of system requirements and identification of system interfaces. Information provided in the Transportation System Concept of Operations includes: the functions and key components of the Transportation System; system component interactions; flows of information within the system; the general operating sequences; and the internal and external factors affecting transportation operations. The Transportation System Concept of Operations reflects OCRWM's overall waste management system policies and mission objectives, and as such provides a description of the preferred state of system operation. The description of general Transportation System operating functions in the Transportation System Concept of Operations is the first step in the OCRWM systems engineering process, establishing the starting point for the lower

Hybrid membrane--PSA system for separating oxygen from air

Science.gov (United States)

Staiger, Chad L [Albuquerque, NM; Vaughn, Mark R [Albuquerque, NM; Miller, A Keith [Albuquerque, NM; Cornelius, Christopher J [Blackburg, VA

2011-01-25

A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc . . . ) and represents a significant advance compared to current technologies.

Oxygen-hydrogen recombination system

International Nuclear Information System (INIS)

Sato, Shuichiro; Takejima, Masaki.

1981-01-01

Purpose: To avoid reduction in the performance of catalyst used for an oxygen-hydrogen recombiner in the off gas processing system of a nuclear reactor. Constitution: A thermometer is provided for the detection of temperature in an oxygen-hydrogen recombiner. A cooling pipe is provided in the recombiner and cooling medium is introduced externally. The cooling medium may be water or air. In accordance with the detection value from the thermometer, ON-OFF control is carried out for a valve to control the flow rate of the cooling medium thereby rendering the temperature in the recombiner to a predetermined value. This can prevent the catalyst from being exposed to high temperature and avoid the reduction in the performance of the catalyst. (Ikeda, J.)

Evaluation of the participation of ferredoxin in oxygen reduction in the photosynthetic electron transport chain of isolated pea thylakoids.

Science.gov (United States)

Kozuleva, Marina A; Ivanov, Boris N

2010-07-01

The contribution to reduction of oxygen by ferredoxin (Fd) to the overall reduction of oxygen in isolated pea thylakoids was studied in the presence of Fd versus Fd + NADP(+). The overall rate of electron transport was measured using a determination of Photosystem II quantum yield from chlorophyll fluorescence parameters, and the rate of oxidation of Fd was measured from the light-induced redox changes of Fd. At low light intensity, increasing Fd concentration from 5 to 30 microM in the absence of NADP(+) increased the proportion of oxygen reduction by Fd from 25-35 to 40-60% in different experiments. This proportion decreased with increasing light intensity. When NADP(+) was added in the presence of 15 microM Fd, which was optimal for the NADP(+) reduction rate, the participation of Fd in the reduction of oxygen was low, no more than 10%, and it also decreased with increasing light intensity. At high light intensity, the overall oxygen reduction rates in the presence of Fd + NADP(+) and in the presence of Fd alone were comparable. The significance of reduction of dioxygen either by water-soluble Fd or by the membrane-bound carriers of the photosynthetic electron transport chain for redox signaling under different light intensities is discussed.

Experimental and thermodynamic study of the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems

International Nuclear Information System (INIS)

Jourdan, J.

2009-11-01

This work is a contribution to the development of innovative concepts for fuel cladding in pressurized water nuclear reactors. This concept implies the insertion of rare earth (erbium and gadolinium) in the zirconium fuel cladding. The determination of phase equilibria in the systems is essential prior to the implementation of such a promising solution. This study consisted in an experimental determination of the erbium-zirconium phase diagram. For this, we used many different techniques in order to obtain diagram data such as solubility limits, solidus, liquidus or invariant temperatures. These data allowed us to present a new diagram, very different from the previous one available in the literature. We also assessed the diagram using the CALPHAD approach. In the gadolinium-zirconium system, we determined experimentally the solubility limits. Those limits had never been determined before, and the values we obtained showed a very good agreement with the experimental and assessed versions of the diagram. Because these alloys are subjected to oxygen diffusion throughout their life, we focused our attention on the erbium-oxygen-zirconium and gadolinium-oxygen-zirconium systems. The first system has been investigated experimentally. The alloys fabrication has been performed using powder metallurgy. In order to obtain pure raw materials, we fabricated powder from erbium and zirconium bulk metals using hydrogen absorption/desorption. The characterisation of the ternary pellets allowed the determination of two ternary isothermal sections at 800 and 1100 C. For the gadolinium-oxygen-zirconium system, we calculated the phase equilibria at temperatures ranging from 800 to 1100 C, using a homemade database compiled from literature assessments of the oxygen-zirconium, gadolinium-zirconium and gadolinia-zirconia systems. Finally, we determined the mechanical properties, in connexion with the microstructure, of industrial quality alloys in order to identify the influence of

Blood Sample Transportation by Pneumatic Transportation Systems

DEFF Research Database (Denmark)

Nybo, Mads; Lund, Merete E; Titlestad, Kjell

2018-01-01

BACKGROUND: Pneumatic transportation systems (PTSs) are increasingly used for transportation of blood samples to the core laboratory. Many studies have investigated the impact of these systems on different types of analyses, but to elucidate whether PTSs in general are safe for transportation...... analysis, and the hemolysis index). CONCLUSIONS: Owing to their high degree of heterogeneity, the retrieved studies were unable to supply evidence for the safety of using PTSs for blood sample transportation. In consequence, laboratories need to measure and document the actual acceleration forces...

Hydrogenation and hydrodeoxygenation of biomass-derived oxygenates to liquid alkanes for transportation fuels

Directory of Open Access Journals (Sweden)

Shaohui Sun

2018-04-01

Full Text Available An attractive approach for the production of transportation fuels from renewable biomass resources is to convert oxygenates into alkanes. In this paper, C5–C20 alkanes formed via the hydrogenation and hydrodeoxygenation of the oligomers of furfuryl alcohol(FA can be used as gasoline, diesel and jet fuel fraction. The first step of the process is the oligomers of FA convert into hydrogenated products over Raney Ni catalyst in a batch reactor. The second step of the process converts hydrogenated products to alkanes via hydrodeoxygenation over different bi-functional catalysts include hydrogenation and acidic deoxidization active sites. After this process, the oxygen content decreased from 22.1 wt% in the oligomers of FA to 0.58 wt% in the hydrodeoxygenation products.

ANALYISIS OF TRANSPORTATION SYSTEMS AND TRANSPORTATION POLICIES IN TURKEY

OpenAIRE

Ali Payıdar AKGÜNGÖR; Abdulmuttalip DEMİREL

2004-01-01

Transportation systems have to be considered and analysed as a whole while transportation demand, becoming as a natural outcome of socioeconomic and socio-cultural structure, is being evaluated. It is desired that transportation system, which will be selected for both passenger and freight transport, should be rapid, economic, safe, causing least harm to environment and appropriate for the conditions of a country. However, it is difficult for a transportation system to have all these properti...

How many oxygen cylinders do you need to take on transport? A nomogram for cylinder size and duration.

Science.gov (United States)

Lutman, D; Petros, A J

2006-09-01

When undertaking patient retrieval, it is important to take adequate supplies of oxygen to ensure patient safety. Oxygen can be delivered via a flowmeter into a facemask or used to drive pneumatic ventilators. Given the lack of space in the back of an ambulance or helicopter, the numbers of cylinders that can be taken is limited, hence the number needed to complete the journey must be carefully calculated prior to embarking. We have produced nomograms to predict how many oxygen cylinders will be consumed during a given journey when using either a flowmeter or a commonly used transport ventilator.

Oxygen limitation modulates pH regulation of catabolism and hydrogenases, multidrug transporters, and envelope composition in Escherichia coli K-12

Directory of Open Access Journals (Sweden)

Radmacher Michael D

2006-10-01

Full Text Available Abstract Background In Escherichia coli, pH regulates genes for amino-acid and sugar catabolism, electron transport, oxidative stress, periplasmic and envelope proteins. Many pH-dependent genes are co-regulated by anaerobiosis, but the overall intersection of pH stress and oxygen limitation has not been investigated. Results The pH dependence of gene expression was analyzed in oxygen-limited cultures of E. coli K-12 strain W3110. E. coli K-12 strain W3110 was cultured in closed tubes containing LBK broth buffered at pH 5.7, pH 7.0, and pH 8.5. Affymetrix array hybridization revealed pH-dependent expression of 1,384 genes and 610 intergenic regions. A core group of 251 genes showed pH responses similar to those in a previous study of cultures grown with aeration. The highly acid-induced gene yagU was shown to be required for extreme-acid resistance (survival at pH 2. Acid also up-regulated fimbriae (fimAC, periplasmic chaperones (hdeAB, cyclopropane fatty acid synthase (cfa, and the "constitutive" Na+/H+ antiporter (nhaB. Base up-regulated core genes for maltodextrin transport (lamB, mal, ATP synthase (atp, and DNA repair (recA, mutL. Other genes showed opposite pH responses with or without aeration, for example ETS components (cyo,nuo, sdh and hydrogenases (hya, hyb, hyc, hyf, hyp. A hypF strain lacking all hydrogenase activity showed loss of extreme-acid resistance. Under oxygen limitation only, acid down-regulated ribosome synthesis (rpl,rpm, rps. Acid up-regulated the catabolism of sugar derivatives whose fermentation minimized acid production (gnd, gnt, srl, and also a cluster of 13 genes in the gadA region. Acid up-regulated drug transporters (mdtEF, mdtL, but down-regulated penicillin-binding proteins (dacACD, mreBC. Intergenic regions containing regulatory sRNAs were up-regulated by acid (ryeA, csrB, gadY, rybC. Conclusion pH regulates a core set of genes independently of oxygen, including yagU, fimbriae, periplasmic chaperones, and nha

Oxygen Transport Membrane Reactors for Oxy-Fuel Combustion and Carbon Capture Purposes

Science.gov (United States)

Falkenstein-Smith, Ryan L.

This thesis investigates oxygen transport membrane reactors (OTMs) for the application of oxy-fuel combustion. This is done by evaluating the material properties and oxygen permeability of different OTM compositions subjected to a variety of operating conditions. The scope of this work consists of three components: (1) evaluate the oxygen permeation capabilities of perovskite-type materials for the application of oxy-fuel combustion; (2) determine the effects of dual-phase membrane compositions on the oxygen permeation performance and membrane characteristics; and (3) develop a new method for estimating the oxygen permeation performance of OTMs utilized for the application of oxy-fuel combustion. SrSc0.1Co0.9O3-delta (SSC) is selected as the primary perovskite-type material used in this research due to its reported high ionic and electronic conductive properties and chemical stability. SSC's oxygen ion diffusivity is investigated using a conductivity relaxation technique and thermogravimetric analysis. Material properties such as chemical structure, morphology, and ionic and electronic conductivity are examined by X-ray diffraction (XRD), Scanning Electron Microscope (SEM), and conductivity testing using a four-probe method, respectively. Oxygen permeation tests study the oxygen permeability OTMs under modified membrane temperatures, sweeping gas flow rates, sweeping gas compositions, membrane configurations, and membrane compositions. When utilizing a pure CO2 sweeping gas, the membrane composition was modified with the addition of Sm0.2Ce0.8O1.9-delta (SDC) at varying wt.% to improve the membranes mechanical stability. A newly developed method to evaluate the oxygen permeation performance of OTMs is also presented by fitting OTM's oxygen permeability to the methane fraction in the sweeping gas composition. The fitted data is used to estimate the overall performance and size of OTMs utilized for the application of oxy-fuel combustion. The findings from this

Spatially monitoring oxygen level in 3D microfabricated cell culture systems using optical oxygen sensing beads

OpenAIRE

Wang, Lin; Acosta, Miguel A.; Leach, Jennie B.; Carrier, Rebecca L.

2013-01-01

Capability of measuring and monitoring local oxygen concentration at the single cell level (tens of microns scale) is often desirable but difficult to achieve in cell culture. In this study, biocompatible oxygen sensing beads were prepared and tested for their potential for real-time monitoring and mapping of local oxygen concentration in 3D micro-patterned cell culture systems. Each oxygen sensing bead is composed of a silica core loaded with both an oxygen sensitive Ru(Ph2phen3)Cl2 dye and ...

Analysis of the clinical backgrounds of patients who developed respiratory acidosis under high‐flow oxygen therapy during emergency transport

Science.gov (United States)

Ogino, Hirokazu; Yamano, Yasuhiko; Ishikawa, Genta; Tomishima, Yutaka; Jinta, Torahiko; Takahashi, Osamu; Chohnabayashi, Naohiko

2015-01-01

Aim High‐flow oxygen is often administered to patients during emergency transport and can sometimes cause respiratory acidosis with disturbed consciousness, thereby necessitating mechanical ventilation. Although oxygen titration in chronic obstructive pulmonary disease patients during emergency transport reduces mortality rates, the clinical risk factors for respiratory acidosis in emergency settings are not fully understood. Therefore, we analyzed the clinical backgrounds of patients who developed respiratory acidosis during pre‐hospital transport. Methods This was a retrospective study of patients who arrived at our hospital by emergency transport in 2010 who received high‐flow oxygen while in transit. Respiratory acidosis was defined by the following arterial blood gas readings: pH, ≤7.35; PaCO 2, ≥45 mmHg; and HCO 3 −, ≥24 mmol/L. The risk factors were identified using multivariable logistic regression analysis. Results In 765 study patients, 66 patients showed respiratory acidosis. The following risk factors for respiratory acidosis were identified: age, ≥65 years (odds ratio [OR] 1.4; 95% confidence interval [CI], 0.7–2.8); transportation time, ≥10 min (OR 2.0; 95% CI, 1.1–3.7); three digits on the Japan Coma Scale (OR 3.1; 95% CI, 1.7–5.8); percutaneous oxygen saturation, ≤90% (OR 1.6; 95% CI, 0.8–3.0); tuberculosis (OR 4.5; 95% CI, 1.4–15.1); asthma (OR 1.8; 95% CI, 0.6–5.3); pneumonia (OR 1.5; 95% CI, 0.7–3.1); and lung cancer (OR 3.9; 95% CI, 1.5–10.1). These underlying diseases as risk factors included both comorbid diseases and past medical conditions. Conclusions The factors identified may contribute to the development of respiratory acidosis. Further studies on preventing respiratory acidosis will improve the quality of emergency medical care. PMID:29123744

VASCULAR PLANTS AS ENGINEERS OF OXYGEN IN AQUATIC SYSTEMS

Science.gov (United States)

The impact of organisms on oxygen is one of the most dramatic examples of ecosystem engineering on Earth. In aquatic systems, which have much lower oxygen concentrations than the atmosphere, vascular aquatic plants can affect oxygen concentrations significantly not only on long t...

Mathematical modeling of oxygen transport in solid oxide fuel cells

Energy Technology Data Exchange (ETDEWEB)

Svensson, Ann Mari

1997-12-31

This thesis develops mathematical models to describe the electrochemical performance of a solid oxide fuel cell cathode based on electrochemical kinetics and mass transfer. The individual effects of various coupled processes are investigated. A one-dimensional model is developed based on porous electrode theory. Two different mechanisms are investigated for the charge transfer reaction. One of these assumes that intermediately adsorbed oxygen atoms are reduced at the electrode/electrolyte interface, similar to the models proposed for metal electrodes. Simulated polarization curves exhibit limited currents due to depletion of oxygen adsorbates at high cathodic overvoltages. An empirical correlation is confirmed to exist between the limiting current an the oxygen partial pressure, however, a similar correlation often assumed to exist between the measured polarization resistance and the oxygen partial pressure could not be justified. For the other model, oxygen vacancies are assumed to be exchanged directly at the electrode/electrolyte interface. The electrochemical behaviour is improved by reducing the oxygen partial pressure, due to increased vacancy concentration of the electrode material. Simulated polarization curves exhibit Tafel-like slopes in the cathodic direction, which are due to polarization concentration, and not activation polarization in the conventional sense. Anodic limiting currents are predicted due to lack of available free sites for vacancy exchange at the cathode side. The thesis also presents a theoretical treatment of current and potential distributions in simple two-dimensional cell geometries, and a two-dimensional model for a porous electrode-electrolyte system for investigation of the effect of interfacial diffusion of adsorbates along the electrode/electrolyte interface. 172 refs., 60 figs., 11 tabs.

Intelligent Freigth Transport Systems

DEFF Research Database (Denmark)

Overø, Helene Martine; Larsen, Allan; Røpke, Stefan

2009-01-01

is to enhance the efficiency and lower the environmental impact in freight transport. In this paper, a pilot project involving real-time waste collection at a Danish waste collection company is described, and a solution approach is proposed. The problem corresponds to the dynamic version of the waste collection......The Danish innovation project entitled “Intelligent Freight Transport Systems” aims at developing prototype systems integrating public intelligent transport systems (ITS) with the technology in vehicles and equipment as well as the IT-systems at various transport companies. The objective...

Life Support Systems: Oxygen Generation and Recovery

Data.gov (United States)

National Aeronautics and Space Administration — The Advanced Exploration Systems (AES) Life Support Systems project Oxygen Generation and Recovery technology development area encompasses several sub-tasks in an...

Lunar and Planetary Science XXXV: Special Session: Oxygen in the Solar System, I

Science.gov (United States)

2004-01-01

The Special Session: Oxygen in the Solar System, I, included the following reports:Oxygen in the Solar System: Origins of Isotopic and Redox Complexity; The Origin of Oxygen Isotope Variations in the Early Solar System; Solar and Solar-Wind Oxygen Isotopes and the Genesis Mission; Solar 18O/17O and the Setting for Solar Birth; Oxygen Isotopes in Early Solar System Materials: A Perspective Based on Microbeam Analyses of Chondrules from CV Carbonaceous Chondrites; Insight into Primordial Solar System Oxygen Reservoirs from Returned Cometary Samples; Tracing Meteorites to Their Sources Through Asteroid Spectroscopy; Redox Conditions Among the Terrestrial Planets; Redox Complexity in Martian Meteorites: Implications for Oxygen in the Terrestrial Planets; Implications of Sulfur Isotopes for the Evolution of Atmospheric Oxygen; Oxygen in the Outer Solar System; and On the Oxidation States of the Galilean Satellites: Implications for Internal Structures.

Properties and performance of BaxSr1-xCo0.8Fe0.2O3-d materials for oxygen transport membranes

NARCIS (Netherlands)

Vente, Jaap F.; McIntosh, S.; McIntosh, Steven; Haije, Wim G.; Bouwmeester, Henricus J.M.

2006-01-01

The present paper discusses the oxygen transport properties, oxygen stoichiometry, phase stability, and chemical and mechanical stability of the perovskites $${\\text{Ba}}_{{0.5}} {\\text{Sr}}_{{0.5}} {\\text{Co}}_{{0.8}} {\\text{Fe}}_{{0.2}} {\\text{O}}_{{3 - \\delta }} $$ (BSCF) and

Aerobic scope and cardiovascular oxygen transport is not compromised at high temperatures in the toad Rhinella marina.

Science.gov (United States)

Overgaard, Johannes; Andersen, Jonas L; Findsen, Anders; Pedersen, Pil B M; Hansen, Kasper; Ozolina, Karlina; Wang, Tobias

2012-10-15

Numerous recent studies convincingly correlate the upper thermal tolerance limit of aquatic ectothermic animals to reduced aerobic scope, and ascribe the decline in aerobic scope to failure of the cardiovascular system at high temperatures. In the present study we investigate whether this 'aerobic scope model' applies to an air-breathing and semi-terrestrial vertebrate Rhinella marina (formerly Bufo marinus). To quantify aerobic scope, we measured resting and maximal rate of oxygen consumption at temperatures ranging from 10 to 40°C. To include potential effects of acclimation, three groups of toads were acclimated chronically at 20, 25 and 30°C, respectively. The absolute difference between resting and maximal rate of oxygen consumption increased progressively with temperature and there was no significant decrease in aerobic scope, even at temperature immediately below the lethal limit (41-42°C). Haematological and cardiorespiratory variables were measured at rest and immediately after maximal activity at benign (30°C) and critically high (40°C) temperatures. Within this temperature interval, both resting and active heart rate increased, and there was no indication of respiratory failure, judged from high arterial oxygen saturation, P(O2) and [Hb(O2)]. With the exception of elevated resting metabolic rate for cold-acclimated toads, we found few differences in the thermal responses between acclimation groups with regard to the cardiometabolic parameters. In conclusion, we found no evidence for temperature-induced cardiorespiratory failure in R. marina, indicating that maintenance of aerobic scope and oxygen transport is unrelated to the upper thermal limit of this air-breathing semi-terrestrial vertebrate.

Oxygen transport and cardiovascular function at extreme altitude: lessons from Operation Everest II

Science.gov (United States)

Sutton, J. R.; Reeves, J. T.; Groves, B. M.; Wagner, P. D.; Alexander, J. K.; Hultgren, H. N.; Cymerman, A.; Houston, C. S.

1992-01-01

Operation Everest II was designed to examine the physiological responses to gradual decompression simulating an ascent of Mt Everest (8,848 m) to an inspired PO2 of 43 mmHg. The principal studies conducted were cardiovascular, respiratory, muscular-skeletal and metabolic responses to exercise. Eight healthy males aged 21-31 years began the "ascent" and six successfully reached the "summit", where their resting arterial blood gases were PO2 = 30 mmHg and PCO2 = 11 mmHg, pH = 7.56. Their maximal oxygen uptake decreased from 3.98 +/- 0.2 L/min at sea level to 1.17 +/- 0.08 L/min at PIO2 43 mmHg. The principal factors responsible for oxygen transport from the atmosphere to tissues were (1) Alveolar ventilation--a four fold increase. (2) Diffusion from the alveolus to end capillary blood--unchanged. (3) Cardiac function (assessed by hemodynamics, echocardiography and electrocardiography)--normal--although maximum cardiac output and heart rate were reduced. (4) Oxygen extraction--maximal with PvO2 14.8 +/- 1 mmHg. With increasing altitude maximal blood and muscle lactate progressively declined although at any submaximal intensity blood and muscle lactate was higher at higher altitudes.

TRANSPORTATION SYSTEM REQUIREMENTS DOCUMENT

International Nuclear Information System (INIS)

2004-01-01

This document establishes the Transportation system requirements for the U.S. Department of Energy's (DOE's) Civilian Radioactive Waste Management System (CRWMS). These requirements are derived from the Civilian Radioactive Waste Management System Requirements Document (CRD). The Transportation System Requirements Document (TSRD) was developed in accordance with LP-3.1Q-OCRWM, Preparation, Review, and Approval of Office of National Transportation Level-2 Baseline Requirements. As illustrated in Figure 1, the TSRD forms a part of the DOE Office of Civilian Radioactive Waste Management (OCRWM) Technical Baseline

Diffusive flux in a model of stochastically gated oxygen transport in insect respiration

Energy Technology Data Exchange (ETDEWEB)

Berezhkovskii, Alexander M. [Mathematical and Statistical Computing Laboratory, Division of Computational Bioscience, Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892 (United States); Shvartsman, Stanislav Y. [Department of Chemical and Biological Engineering and Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey 08544 (United States)

2016-05-28

Oxygen delivery to insect tissues is controlled by transport through a branched tubular network that is connected to the atmosphere by valve-like gates, known as spiracles. In certain physiological regimes, the spiracles appear to be randomly switching between open and closed states. Quantitative analysis of this regime leads a reaction-diffusion problem with stochastically switching boundary condition. We derive an expression for the diffusive flux at long times in this problem. Our approach starts with the derivation of the passage probability for a single particle that diffuses between a stochastically gated boundary, which models the opening and closing spiracle, and the perfectly absorbing boundary, which models oxygen absorption by the tissue. This passage probability is then used to derive an expression giving the diffusive flux as a function of the geometric parameters of the tube and characteristic time scales of diffusion and gate dynamics.

77 FR 11385 - Security Considerations for Lavatory Oxygen Systems

Science.gov (United States)

2012-02-27

... considerations for lavatory oxygen systems (77 FR 12550). The interim final rule addresses a security... and taken to restore the oxygen system with a design that would consider the security risk. Boeing... [Docket No. FAA-2011-0186; Amdt. Nos. 21-94, 25-133, 121-354, 129-50; SFAR 111] RIN 2120-AJ92 Security...

A theoretical model for the effects of reduced hemoglobin-oxygen affinity on tumor oxygenation

International Nuclear Information System (INIS)

Kavanagh, Brian D.; Secomb, Timothy W.; Hsu, Richard; Lin, P.-S.; Venitz, Jurgen; Dewhirst, Mark W.

2002-01-01

Purpose: To develop a theoretical model for oxygen delivery to tumors, and to use the model to simulate the effects of changing the affinity of hemoglobin for oxygen on tumor oxygenation. Methods and Materials: Hemoglobin affinity is expressed in terms of P 50 , the partial pressure of oxygen (Po 2 ) at half saturation. Effects of changing P 50 on arterial Po 2 are predicted using an effective vessel approach to describe diffusive oxygen transport in the lungs, assuming fixed systemic oxygen demand and fixed blood flow rate. The decline in oxygen content of blood as it flows through normal tissue before entering the tumor region is assumed fixed. The hypoxic fraction of the tumor region is predicted using a three-dimensional simulation of diffusion from a network of vessels whose geometry is derived from observations of tumor microvasculature in the rat. Results: In air-breathing rats, predicted hypoxic fraction decreases with moderate increases in P 50 , but increases with further increases of P 50 , in agreement with previous experimental results. In rats breathing hyperoxic gases, and in humans breathing either normoxic or hyperoxic gases, increased P 50 is predicted to improve tumor oxygenation. Conclusions: The results support the administration of synthetic agents to increase P 50 during radiation treatment of tumors

Oxygen discharge and post-discharge kinetics experiments and modeling for the electric oxygen-iodine laser system.

Science.gov (United States)

Palla, A D; Zimmerman, J W; Woodard, B S; Carroll, D L; Verdeyen, J T; Lim, T C; Solomon, W C

2007-07-26

Laser oscillation at 1315 nm on the I(2P1/2)-->I(2P3/2) transition of atomic iodine has been obtained by a near resonant energy transfer from O2(a1Delta) produced using a low-pressure oxygen/helium/nitric oxide discharge. In the electric discharge oxygen-iodine laser (ElectricOIL) the discharge production of atomic oxygen, ozone, and other excited species adds levels of complexity to the singlet oxygen generator (SOG) kinetics which are not encountered in a classic purely chemical O2(a1Delta) generation system. The advanced model BLAZE-IV has been introduced to study the energy-transfer laser system dynamics and kinetics. Levels of singlet oxygen, oxygen atoms, and ozone are measured experimentally and compared with calculations. The new BLAZE-IV model is in reasonable agreement with O3, O atom, and gas temperature measurements but is under-predicting the increase in O2(a1Delta) concentration resulting from the presence of NO in the discharge and under-predicting the O2(b1Sigma) concentrations. A key conclusion is that the removal of oxygen atoms by NOX species leads to a significant increase in O2(a1Delta) concentrations downstream of the discharge in part via a recycling process; however, there are still some important processes related to the NOX discharge kinetics that are missing from the present modeling. Further, the removal of oxygen atoms dramatically inhibits the production of ozone in the downstream kinetics.

Lunar transportation system

Science.gov (United States)

1993-07-01

The University Space Research Association (USRA) requested the University of Minnesota Spacecraft Design Team to design a lunar transportation infrastructure. This task was a year long design effort culminating in a complete conceptual design and presentation at Johnson Space Center. The mission objective of the design group was to design a system of vehicles to bring a habitation module, cargo, and crew to the lunar surface from LEO and return either or both crew and cargo safely to LEO while emphasizing component commonality, reusability, and cost effectiveness. During the course of the design, the lunar transportation system (LTS) has taken on many forms. The final design of the system is composed of two vehicles, a lunar transfer vehicle (LTV) and a lunar excursion vehicle (LEV). The LTV serves as an efficient orbital transfer vehicle between the earth and the moon while the LEV carries crew and cargo to the lunar surface. Presented in the report are the mission analysis, systems layout, orbital mechanics, propulsion systems, structural and thermal analysis, and crew systems, avionics, and power systems for this lunar transportation concept.

Implementing oxygen control in chip-based cell and tissue culture systems.

Science.gov (United States)

Oomen, Pieter E; Skolimowski, Maciej D; Verpoorte, Elisabeth

2016-09-21

Oxygen is essential in the energy metabolism of cells, as well as being an important regulatory parameter influencing cell differentiation and function. Interest in precise oxygen control for in vitro cultures of tissues and cells continues to grow, especially with the emergence of the organ-on-a-chip and the desire to emulate in vivo conditions. This was recently discussed in this journal in a Critical Review by Brennan et al. (Lab Chip (2014). DOI: ). Microfluidics can be used to introduce flow to facilitate nutrient supply to and waste removal from in vitro culture systems. Well-defined oxygen gradients can also be established. However, cells can quickly alter the oxygen balance in their vicinity. In this Tutorial Review, we expand on the Brennan paper to focus on the implementation of oxygen analysis in these systems to achieve continuous monitoring. Both electrochemical and optical approaches for the integration of oxygen monitoring in microfluidic tissue and cell culture systems will be discussed. Differences in oxygen requirements from one organ to the next are a challenging problem, as oxygen delivery is limited by its uptake into medium. Hence, we discuss the factors determining oxygen concentrations in solutions and consider the possible use of artificial oxygen carriers to increase dissolved oxygen concentrations. The selection of device material for applications requiring precise oxygen control is discussed in detail, focusing on oxygen permeability. Lastly, a variety of devices is presented, showing the diversity of approaches that can be employed to control and monitor oxygen concentrations in in vitro experiments.

Dynamic Factors Affecting Gaseous Ligand Binding in an Artificial Oxygen Transport Protein‡

Science.gov (United States)

Zhang, Lei; Andersen, Eskil M.E.; Khajo, Abdelahad; Magliozzo, Richard S.; Koder, Ronald L.

2013-01-01

We report the functional analysis of an artificial hexacoordinate oxygen transport protein, HP7, which operates via a mechanism similar to that of human neuroglobin and cytoglobin: the destabilization of one of two heme-ligating histidine residues. In the case of HP7 this is the result of the coupling of histidine side chain ligation with the burial of three charged glutamate residues on the same helix. Here we compare gaseous ligand binding, including rates, affinities and oxyferrous state lifetimes, of both heme binding sites in HP7. We find that despite the identical sequence of helices in both binding sites, there are differences in oxygen affinity and oxyferrous state lifetime which may be the result of differences in the freedom of motion imposed by the candelabra fold on the two sites of the protein. We further examine the effect of mutational removal of the buried glutamates on function. Heme iron in the ferrous state of this mutant is rapidly oxidized when when exposed to oxygen. Compared to HP7, distal histidine affinity is increased by a 22-fold decrease in the histidine ligand off-rate. EPR comparison of these ferric hemoproteins demonstrates that the mutation increases disorder at the heme binding site. NMR-detected deuterium exchange demonstrates that the mutation greatly increases water penetration into the protein core. The inability of the mutant protein to bind oxygen may be due to increased water penetration, the large decrease in binding rate caused by the increase in distal histidine affinity, or a combination of the two factors. Together these data underline the importance of the control of protein dynamics in the design of functional artificial proteins. PMID:23249163

Oxygen transport through soft contact lens and cornea: Lens characterization and metabolic modeling

Science.gov (United States)

Chhabra, Mahendra

The human cornea requires oxygen to sustain metabolic processes critical for its normal functioning. Any restriction to corneal oxygen supply from the external environment (e.g., by wearing a low oxygen-permeability contact lens) can lead to hypoxia, which may cause corneal edema (swelling), limbal hyperemia, neovascularization, and corneal acidosis. The need for adequate oxygen to the cornea is a major driving force for research and development of hypertransmissible soft contact lenses (SCLs). Currently, there is no standard technique for measuring oxygen permeability (Dk) of hypertransmissible silicone-hydrogel SCLs. In this work, an electrochemistry-based polarographic apparatus was designed, built, and operated to measure oxygen permeability in hypertransmissible SCLs. Unlike conventional methods where a range of lens thickness is needed for determining oxygen permeabilities of SCLs, this apparatus requires only a single lens thickness. The single-lens permeameter provides a reliable, efficient, and economic tool for measuring oxygen permeabilities of commercial hypertransmissible SCLs. The single-lens permeameter measures not only the product Dk, but, following modification, it measures separately diffusivity, D, and solubility, k, of oxygen in hypertransmissible SCLs. These properties are critical for designing better lens materials that ensure sufficient oxygen supply to the cornea. Metabolism of oxygen in the cornea is influenced by contact-lens-induced hypoxia, diseases such as diabetes, surgery, and drug treatment, Thus, estimation of the in-vivo corneal oxygen consumption rate is essential for gauging adequate oxygen supply to the cornea. Therefore, we have developed an unsteady-state reactive-diffusion model for the cornea-contact-lens system to determine in-vivo human corneal oxygen-consumption rate. Finally, a metabolic model was developed to determine the relation between contact-lens oxygen transmissibility (Dk/L) and corneal oxygen deficiency. A

Metabolic changers in oxygen transport in patients with diabetes mellitus type 2. Possibilities for correction

Directory of Open Access Journals (Sweden)

I Z Bondarenko

2009-06-01

Full Text Available Diabetes mellitus type 2 (DM2 - is an independent predictor of development of heart failure (HF. Spiroergometry - is a method for studying blood gas exchange parameters, commonly used for specification of HF. The purpose: 1. To study features of gas exchange at patients with DM2 without cardiovascular diseases in comparison with healthy control. 2. To estimate efficiency of metoprolol for correction of metabolic disturbances in patients with DM2. Materials and methods: 12 patients with DM2, aged 48,4±8, without history of cardiovascular diseases and 15 control subjects, aged 43,6±8 underwent cardio-pulmonary exercise test on treadmill, according to Bruce protocol. Exercise energy, VO2 peak, MET, VE max, VCO2 production were observed. Results: Patients with DM2 had a reduced exercise duration (p<0,001, lower peak oxygen consumption (p<0,001, VCO2 production and MET (p<0,005, than controls, representing the same state of hypoxia as in patients with ischemic heart disease (IHD of functional class 2. The introduction of metoprolol to patients with DM2 significantly increased exercise duration time and VCO2 production (p<0,005. Conclusions: 1. VO2 consumption in patients with DM2 is decreased to the same levels as in persons without DM2, who have IHD and HF. 2. Changes in oxygen-transport in persons with DM2 may serve as a marker of negative influence of the disease on cardiovascular system status. 3. Metoprolol improves parameters of cardio-respiratory system in patients with DM2.

Canadian hydrocarbon transportation system : transportation assessment

International Nuclear Information System (INIS)

2006-06-01

This document provided an assessment of the Canadian hydrocarbon transportation system. In addition to regulating the construction and operation of Canada's 45,000 km of pipeline that cross international and provincial borders, Canada's National Energy Board (NEB) regulates the trade of natural gas, oil and natural gas liquids. The ability of pipelines to delivery this energy is critical to the country's economic prosperity. The pipeline system includes large-diameter, cross-country, high-pressure natural gas pipelines, low-pressure crude oil and oil products pipelines and small-diameter pipelines. In order to assess the hydrocarbon transportation system, staff at the NEB collected data from pipeline companies and a range of publicly available sources. The Board also held discussions with members of the investment community regarding capital markets and emerging issues. The assessment focused largely on evaluating whether Canadians benefit from an efficient energy infrastructure and markets. The safety and environmental integrity of the pipeline system was also evaluated. The current adequacy of pipeline capacity was assessed based on price differentials compared with firm service tolls for major transportation paths; capacity utilization on pipelines; and, the degree of apportionment on major oil pipelines. The NEB concluded that the Canadian hydrocarbon transportation system is working effectively, with an adequate capacity in place on existing natural gas pipelines, but with a tight capacity on oil pipelines. It was noted that shippers continue to indicate that they are reasonably satisfied with the services provided by pipeline companies and that the NEB-regulated pipeline companies are financially stable. 14 refs, 11 tabs., 28 figs., 4 appendices

The indium-oxygen system, ch. 5

International Nuclear Information System (INIS)

Dillen, A.J. van

1977-01-01

This chapter is divided into three sections: 1) a survey of the literature concerning the indiumoxygen system, 2) the adsorption of oxygen at pure and partially oxidized indium surfaces in the temperature range 20-180degC, and 3) the oxidation of indium at temperatures above 180degC. The oxygen uptake is determined volumetrically and gravimetrically. The influence of the melting point is considered and the results are compared with data from the literature. The oxide layer is amorphous at lower temperatures but above 350degC, crystallisation of In 2 O 3 takes place

Optimizing oxygenation and intubation conditions during awake fibre-optic intubation using a high-flow nasal oxygen-delivery system.

Science.gov (United States)

Badiger, S; John, M; Fearnley, R A; Ahmad, I

2015-10-01

Awake fibre-optic intubation is a widely practised technique for anticipated difficult airway management. Despite the administration of supplemental oxygen during the procedure, patients are still at risk of hypoxia because of the effects of sedation, local anaesthesia, procedural complications, and the presence of co-morbidities. Traditionally used oxygen-delivery devices are low flow, and most do not have a sufficient reservoir or allow adequate fresh gas flow to meet the patient's peak inspiratory flow rate, nor provide an adequate fractional inspired oxygen concentration to prevent desaturation should complications arise. A prospective observational study was conducted using a high-flow humidified transnasal oxygen-delivery system during awake fibre-optic intubation in 50 patients with anticipated difficult airways. There were no episodes of desaturation or hypercapnia using the high-flow system, and in all patients the oxygen saturation improved above baseline values, despite one instance of apnoea resulting from over-sedation. All patients reported a comfortable experience using the device. The high-flow nasal oxygen-delivery system improves oxygenation saturation, decreases the risk of desaturation during the procedure, and potentially, optimizes conditions for awake fibre-optic intubation. The soft nasal cannulae uniquely allow continuous oxygenation and simultaneous passage of the fibrescope and tracheal tube. The safety of the procedure may be increased, because any obstruction, hypoventilation, or periods of apnoea that may arise may be tolerated for longer, allowing more time to achieve ventilation in an optimally oxygenated patient. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Osmotic phenomena in application for hyperbaric oxygen treatment.

Science.gov (United States)

Babchin, A; Levich, E; Melamed M D, Y; Sivashinsky, G

2011-03-01

Hyperbaric oxygen (HBO) treatment defines the medical procedure when the patient inhales pure oxygen at elevated pressure conditions. Many diseases and all injuries are associated with a lack of oxygen in tissues, known as hypoxia. HBO provides an effective method for fast oxygen delivery in medical practice. The exact mechanism of the oxygen transport under HBO conditions is not fully identified. The objective of this article is to extend the colloid and surface science basis for the oxygen transport in HBO conditions beyond the molecular diffusion transport mechanism. At a pressure in the hyperbaric chamber of two atmospheres, the partial pressure of oxygen in the blood plasma increases 10 times. The sharp increase of oxygen concentration in the blood plasma creates a considerable concentration gradient between the oxygen dissolved in the plasma and in the tissue. The concentration gradient of oxygen as a non-electrolyte solute causes an osmotic flow of blood plasma with dissolved oxygen. In other words, the molecular diffusion transport of oxygen is supplemented by the convective diffusion raised due to the osmotic flow, accelerating the oxygen delivery from blood to tissue. A non steady state equation for non-electrolyte osmosis is solved asymptotically. The solution clearly demonstrates two modes of osmotic flow: normal osmosis, directed from lower to higher solute concentrations, and anomalous osmosis, directed from higher to lower solute concentrations. The fast delivery of oxygen from blood to tissue is explained on the basis of the strong molecular interaction between the oxygen and the tissue, causing an influx of oxygen into the tissue by convective diffusion in the anomalous osmosis process. The transport of the second gas, nitrogen, dissolved in the blood plasma, is also taken into the consideration. As the patient does not inhale nitrogen during HBO treatment, but exhales it along with oxygen and carbon dioxide, the concentration of nitrogen in blood

Dynamic factors affecting gaseous ligand binding in an artificial oxygen transport protein.

Science.gov (United States)

Zhang, Lei; Andersen, Eskil M E; Khajo, Abdelahad; Magliozzo, Richard S; Koder, Ronald L

2013-01-22

We report the functional analysis of an artificial hexacoordinate oxygen transport protein, HP7, which operates via a mechanism similar to that of human neuroglobin and cytoglobin: the destabilization of one of two heme-ligating histidine residues. In the case of HP7, this is the result of the coupling of histidine side chain ligation with the burial of three charged glutamate residues on the same helix. Here we compare gaseous ligand binding, including rates, affinities, and oxyferrous state lifetimes, of both heme binding sites in HP7. We find that despite the identical sequence of helices in both binding sites, there are differences in oxygen affinity and oxyferrous state lifetime that may be the result of differences in the freedom of motion imposed by the candelabra fold on the two sites of the protein. We further examine the effect of mutational removal of the buried glutamates on function. Heme iron in the ferrous state of this mutant is rapidly oxidized when exposed to oxygen. Compared to that of HP7, the distal histidine affinity is increased by a 22-fold decrease in the histidine ligand off rate. Electron paramagnetic resonance comparison of these ferric hemoproteins demonstrates that the mutation increases the level of disorder at the heme binding site. Nuclear magnetic resonance-detected deuterium exchange demonstrates that the mutation greatly increases the degree of penetration of water into the protein core. The inability of the mutant protein to bind oxygen may be due to an increased level of water penetration, the large decrease in binding rate caused by the increase in distal histidine affinity, or a combination of the two factors. Together, these data underline the importance of the control of protein dynamics in the design of functional artificial proteins.

A novel outer-membrane anion channel (porin) as part of a putatively two-component transport system for 4-toluenesulphonate in Comamonas testosteroni T-2

OpenAIRE

Mampel, Jörg; Maier, Elke; Tralau, Tewes; Ruff, Jürgen; Benz, Roland; Cook, Alasdair M.

2004-01-01

Inducible mineralization of TSA (4-toluenesulphonate) by Comamonas testosteroni T-2 is initiated by a secondary transport system, followed by oxygenation and oxidation by TsaMBCD to 4-sulphobenzoate under the regulation of TsaR and TsaQ. Evidence is presented for a novel, presumably two-component transport system (TsaST). It is proposed that TsaT, an outer-membrane porin, formed an anion-selective channel that works in co-operation with the putative secondary transporter, TsaS, located in the...

Evaluation of Additively Manufactured Metals for Use in Oxygen Systems Project

Science.gov (United States)

Tylka, Jonathan; Cooper, Ken; Peralta, Stephen; Wilcutt, Terrence; Hughitt, Brian; Generazio, Edward

2016-01-01

Space Launch System, Commercial Resupply, and Commercial Crew programs have published intent to use additively manufactured (AM) components in propulsion systems and are likely to include various life support systems in the future. Parts produced by these types of additive manufacturing techniques have not been fully evaluated for use in oxygen systems and the inherent risks have not been fully identified. Some areas of primary concern in the SLS process with respect to oxygen compatibility may be the porosity of the printed parts, fundamental differences in microstructure of an AM part as compared to traditional materials, or increased risk of shed metal particulate into an oxygen system. If an ignition were to occur the printed material could be more flammable than components manufactured from a traditional billet of raw material and/or present a significant hazards if not identified and rigorously studied in advance of implementation into an oxygen system.

Investigation on the oxygen transport mechanisms in the Sarcheshmeh waste rock dumps

Directory of Open Access Journals (Sweden)

Saeed Yousefi

2015-04-01

Full Text Available Introduction Pyrite oxidation and acid mine drainage (AMD are the serious environmental problems associated with the mining activities in sulphide ores. The rate of pyrite oxidation is governed by the availability of oxygen (Borden, 2003. Therefore, the identifying oxygen supplying mechanism is one of the most important issues related to the environmental assessment of waste rock dumps (Cathles and Apps, 1975; Jaynes et al., 1984; Davis and Ritchie, 1986. Although comprehensive researches were performed on the mathematical description of oxygen transport processes using the numerical modeling (Morin et al., 1988; Blowes et al., 1991; Wunderly et al., 1986; Elberling et al., 1994; Jannesar Malakooti et al., 2014, so far, the interactions between these processes and geochemical and mineralogical characteristics has not been studied especially in waste rock dumps. Therefore the main objective of this study is to identify the evidences for knowing the oxygen transport mechanisms in the waste dumps and also, its role in intensity of pyrite oxidation. It is expected that such these structural studies could be useful for better understanding of dominant processes in numerical modeling and also providing environmental management strategies in the study area and other sites by similar characteristics. Materials and Methods In this study, thirty solid samples were collected from six excavated trenches in the waste rock dumps No. 19 and 31 of the Sarcheshmeh porphyry copper mine. Collected samples were studied using several methods such as XRD, ASTM-D2492, paste pH and grain size distribution. The results obtained from these methods were used with the field observations in order to characterize some detail information about oxygen supplying mechanisms for oxidation reactions in the waste rock dumps. Result The main minerals found by the XRD analysis were quartz and muscovite which were present in all samples. Pyrite, orthose, albite, and chlorite were also

Canadian pipeline transportation system : transportation assessment

International Nuclear Information System (INIS)

2009-07-01

In addition to regulating the construction and operation of 70,000 km of oil and natural gas pipelines in Canada, the National Energy Board (NEB) regulates the trade of natural gas, oil and natural gas liquids. This report provided an assessment of the Canadian hydrocarbon transportation system in relation to its ability to provide a robust energy infrastructure. Data was collected from NEB-regulated pipeline companies and a range of publicly available sources to determine if adequate pipeline capacity is in place to transport products to consumers. The NEB also used throughput and capacity information received from pipeline operators as well as members of the investment community. The study examined price differentials compared with firm service tolls for transportation paths, as well as capacity utilization on pipelines and the degree of apportionment on major oil pipelines. This review indicated that in general, the Canadian pipeline transportation system continues to work effectively, with adequate pipeline capacity in place to move products to consumers who need them. 9 tabs., 30 figs., 3 appendices.

Blood oxygen and carbon dioxide transport in man

OpenAIRE

McElderry, Linda A.

1981-01-01

The effect of long term domiciliary oxygen therapy on the position and shape of the oxygen dissociation curve, together with other haematologic variables such as 2,3- diphosphoglycerate (2,3-DPG), haemoglobin concentration, packed cell volume, mean corpuscular haemoglobin concentration, and arterial blood gas and pH values, has been studied in patients with chronic bronchitis. Twenty-six patients were randomly allocated to receive either no oxygen therapy or 15 hours p...

The Place of Railway Transport in Romania’s Transport System

OpenAIRE

Dãneci-Pãtrãu Daniel; Coca Carmen Elena

2012-01-01

The transport activity in all its forms represents one of the most complex sections of an economy, but also an important factor of influence over the quality of life, that is why current preoccupations of international organisms are oriented towards measures meant to develop performing transport systems and compatible with the environment. In the article the main activities and resources of Romania’s railway transport system are presented , the place of the railway transport in the transport ...

Sustained in situ measurements of dissolved oxygen, methane and water transport processes in the benthic boundary layer at MC118, northern Gulf of Mexico

Science.gov (United States)

Martens, Christopher S.; Mendlovitz, Howard P.; Seim, Harvey; Lapham, Laura; D'Emidio, Marco

2016-07-01

Within months of the BP Macondo Wellhead blowout, elevated methane concentrations within the water column revealed a significant retention of light hydrocarbons in deep waters plus corresponding dissolved oxygen (DO) deficits. However, chemical plume tracking efforts were hindered by a lack of in situ monitoring capabilities. Here, we describe results from in situ time-series, lander-based investigations of physical and biogeochemical processes controlling dissolved oxygen, and methane at Mississippi Canyon lease block 118 ( 18 km from the oil spill) conducted shortly after the blowout through April 2012. Multiple sensor arrays plus open-cylinder flux chambers (;chimneys;) deployed from a benthic lander collected oxygen, methane, pressure, and current speed and direction data within one meter of the seafloor. The ROVARD lander system was deployed for an initial 21-day test experiment (9/13/2010-10/04/2010) at 882 m depth before a longer 160-day deployment (10/24/2011-4/01/2012) at 884 m depth. Temporal variability in current directions and velocities and water temperatures revealed strong influences of bathymetrically steered currents and overlying along-shelf flows on local and regional water transport processes. DO concentrations and temperature were inversely correlated as a result of water mass mixing processes. Flux chamber measurements during the 160-day deployment revealed total oxygen utilization (TOU) averaging 11.6 mmol/m2 day. Chimney DO concentrations measured during the 21-day deployment exhibited quasi-daily variations apparently resulting from an interaction between near inertial waves and the steep topography of an elevated scarp immediately adjacent to the 21-day deployment site that modulated currents at the top of the chimney. Variability in dissolved methane concentrations suggested significant temporal variability in gas release from nearby hydrocarbon seeps and/or delivery by local water transport processes. Free-vehicle (lander) monitoring

Oxygen transport and myocardial function after the administration of albumin 5%, hydroxyethylstarch 6% and succinylated gelatine 4% to rabbits

NARCIS (Netherlands)

Himpe, D. G.; de Hert, S. G.; Vermeyen, K. M.; Adriaensen, H. F.

2002-01-01

BACKGROUND AND OBJECTIVE: The effects of administering albumin 5%, hydroxyethylstarch 6% and succinylated gelatine 4% on oxygen transport and left ventricular function were prospectively investigated in different experimental conditions: baseline, fluid load, after 10 min of myocardial ischaemia and

Electrical railway transportation systems

CERN Document Server

Brenna, Morris; Zaninelli, Dario

2018-01-01

Allows the reader to deepen their understanding of various technologies for both fixed power supply installations of railway systems and for railway rolling stock. This book explores the electric railway systems that play a crucial role in the mitigation of congestion and pollution caused by road traffic. It is divided into two parts: the first covering fixed power supply systems, and the second concerning the systems for railway rolling stock. In particular, after a historical introduction to the framework of technological solutions in current use, the authors investigate electrification systems for the power supply of rail vehicles, trams, and subways. Electrical Railway Transportation Systems explores the direct current systems used throughout the world for urban and suburban transport, which are also used in various countries for regional transport. It provides a study of alternating current systems, whether for power supply frequency or for special railway frequency, that are used around the world for ...

14 CFR 25.1445 - Equipment standards for the oxygen distributing system.

Science.gov (United States)

2010-01-01

... distributing system. 25.1445 Section 25.1445 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT... Miscellaneous Equipment § 25.1445 Equipment standards for the oxygen distributing system. (a) When oxygen is supplied to both crew and passengers, the distribution system must be designed for either— (1) A source of...

The Mechanisms of Oxygen Reduction in the Terminal Reducing Segment of the Chloroplast Photosynthetic Electron Transport Chain.

Science.gov (United States)

Kozuleva, Marina A; Ivanov, Boris N

2016-07-01

The review is dedicated to ascertainment of the roles of the electron transfer cofactors of the pigment-protein complex of PSI, ferredoxin (Fd) and ferredoxin-NADP reductase in oxygen reduction in the photosynthetic electron transport chain (PETC) in the light. The data regarding oxygen reduction in other segments of the PETC are briefly analyzed, and it is concluded that their participation in the overall process in the PETC under unstressful conditions should be insignificant. Data concerning the contribution of Fd to the oxygen reduction in the PETC are examined. A set of collateral evidence as well as results of direct measurements of the involvement of Fd in this process in the presence of isolated thylakoids led to the inference that this contribution in vivo is negligible. The increase in oxygen reduction rate in the isolated thylakoids in the presence of either Fd or Fd plus NADP + under increasing light intensity was attributed to the increase in oxygen reduction executed by the membrane-bound oxygen reductants. Data are presented which imply that a main reductant of the O 2 molecule in the terminal reducing segment of the PETC is the electron transfer cofactor of PSI, phylloquinone. The physiological significance of characteristic properties of oxygen reductants in this segment of the PETC is discussed. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Single-cell measurement of red blood cell oxygen affinity.

Science.gov (United States)

Di Caprio, Giuseppe; Stokes, Chris; Higgins, John M; Schonbrun, Ethan

2015-08-11

Oxygen is transported throughout the body by hemoglobin (Hb) in red blood cells (RBCs). Although the oxygen affinity of blood is well-understood and routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of RBC volume and Hb concentration are taken millions of times per day by clinical hematology analyzers, and they are important factors in determining the health of the hematologic system. To better understand the variability and determinants of oxygen affinity on a cellular level, we have developed a system that quantifies the oxygen saturation, cell volume, and Hb concentration for individual RBCs in high throughput. We find that the variability in single-cell saturation peaks at an oxygen partial pressure of 2.9%, which corresponds to the maximum slope of the oxygen-Hb dissociation curve. In addition, single-cell oxygen affinity is positively correlated with Hb concentration but independent of osmolarity, which suggests variation in the Hb to 2,3-diphosphoglycerate (2-3 DPG) ratio on a cellular level. By quantifying the functional behavior of a cellular population, our system adds a dimension to blood cell analysis and other measurements of single-cell variability.

ADVANCES IN ZERO ENERGY TRANSPORTATION SYSTEMS

OpenAIRE

Ahmad, Othman

2017-01-01

Hyperloop mass transportation systems are activelydeveloped at the moment. They represent the forefront development of the ZeroEnergy Transportation systems where air drag is minimized by travelling in avacuum and friction is reduced by non-contact bearings. Hyperloop supportersare confident that the cost of their transportation systems would be lowcompared to existing transportation systems because of the low loss andtherefore low energy consumption as well as other cost-saving techniquesdoc...

High-Energy Beam Transport system

International Nuclear Information System (INIS)

Melson, K.E.; Farrell, J.A.; Liska, D.J.

1979-01-01

The High-Energy Beam Transport (HEBT) system for the Fusion Materials Irradiation Test (FMIT) Facility is to be installed at the Hanford Engineering Development Laboratory (HEDL) at Richland, Washington. The linear accelerator must transport a large emittance, high-current, high-power, continuous-duty deuteron beam with a large energy spread either to a lithium target or a beam stop. A periodic quadrupole and bending-magnet system provides the beam transport and focusing on target with small beam aberrations. A special rf cavity distributes the energy in the beam so that the Bragg Peak is distributed within the lithium target. Operation of the rf control system, the Energy Dispersion Cavity (EDC), and the beam transport magnets is tested on the beam stop during accelerator turn-on. Characterizing the beam will require extensions of beam diagnostic techniques and noninterceptive sensors. Provisions are being made in the facility for suspending the transport system from overhead supports using a cluster system to simplify maintenance and alignment techniques

Feasibility of electrokinetic oxygen supply for soil bioremediation purposes.

Science.gov (United States)

Mena Ramírez, E; Villaseñor Camacho, J; Rodrigo Rodrigo, M A; Cañizares Cañizares, P

2014-12-01

This paper studies the possibility of providing oxygen to a soil by an electrokinetic technique, so that the method could be used in future aerobic polluted soil bioremediation treatments. The oxygen was generated from the anodic reaction of water electrolysis and transported to the soil in a laboratory-scale electrokinetic cell. Two variables were tested: the soil texture and the voltage gradient. The technique was tested in two artificial soils (clay and sand) and later in a real silty soil, and three voltage gradients were used: 0.0 (control), 0.5, and 1.0 V cm(-1). It was observed that these two variables strongly influenced the results. Oxygen transport into the soil was only available in the silty and sandy soils by oxygen diffusion, obtaining high dissolved oxygen concentrations, between 4 and 9 mg L(-1), useful for possible aerobic biodegradation processes, while transport was not possible in fine-grained soils such as clay. Electro-osmotic flow did not contribute to the transport of oxygen, and an increase in voltage gradients produced higher oxygen transfer rates. However, only a minimum fraction of the electrolytically generated oxygen was efficiently used, and the maximum oxygen transport rate observed, approximately 1.4 mgO2 L(-1)d(-1), was rather low, so this technique could be only tested in slow in-situ biostimulation processes for organics removal from polluted soils. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inactive trials of transport systems

International Nuclear Information System (INIS)

Haberlin, M.M.; Hardy, A.R.

1985-06-01

The design and manufacture of a mock-up of a crate handling and size reduction (CHSR) facility, an experimental programme on the evaluation of a commercial air-transporter, and the selection, manufacture and commissioning trials of an integrated conveyor system for transporting crated waste into and within the mock-up facility, are considered. The mock-up facility was used for the test programme on the air-transporter and conveyor system. The air-transporter was considered suitable for transporting waste on the metal floor in the main dismantling area of the CHSR facility because it can tolerate asymmetric loading, the exhaust air flow liberated from the air-pads is low and it has excellent manoeuvrability. Commissioning trials were carried out on a commercial conveyor system consisting of unpowered rollers in the reception area, a powered slatted conveyor in the air-lock and an unpowered roller table placed on the air-transporter in the working area. It was demonstrated that a large asymmetrically loaded wooden crate can be transported into and within the facility by this method. Further design and experimental work necessary before the system can be used for remote operation is discussed. (author)

Single-cell measurement of red blood cell oxygen affinity

OpenAIRE

Caprio, Di; Stokes, Chris; Higgins, John M.; Schonbrun, Ethan

2015-01-01

Oxygen is transported throughout the body by hemoglobin in red blood cells. While the oxygen affinity of blood is well understood and is routinely assessed in patients by pulse oximetry, variability at the single-cell level has not been previously measured. In contrast, single-cell measurements of red blood cell volume and hemoglobin concentration are taken millions of times per day by clinical hematology analyzers and are important factors in determining the health of the hematologic system....

Intelligent transportation systems problems and perspectives

CERN Document Server

Pamuła, Wiesław

2016-01-01

This book presents a discussion of problems encountered in the deployment of Intelligent Transport Systems (ITS). It puts emphasis on the early tasks of designing and proofing the concept of integration of technologies in Intelligent Transport Systems. In its first part the book concentrates on the design problems of urban ITS. The second part of the book features case studies representative for the different modes of transport. These are freight transport, rail transport and aerospace transport encompassing also space stations. The book provides ideas for deployment which may be developed by scientists and engineers engaged in the design of Intelligent Transport Systems. It can also be used in the training of specialists, students and post-graduate students in universities and transport high schools.    .

49 CFR 37.33 - Airport transportation systems.

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Airport transportation systems. 37.33 Section 37.33 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.33 Airport transportation systems. (a) Transportation...

An evaluation of oxygen systems for treatment of childhood pneumonia

Directory of Open Access Journals (Sweden)

Rudan Igor

2011-04-01

Full Text Available Abstract Background Oxygen therapy is recommended for all of the 1.5 – 2.7 million young children who consult health services with hypoxemic pneumonia each year, and the many more with other serious conditions. However, oxygen supplies are intermittent throughout the developing world. Although oxygen is well established as a treatment for hypoxemic pneumonia, quantitative evidence for its effect is lacking. This review aims to assess the utility of oxygen systems as a method for reducing childhood mortality from pneumonia. Methods Aiming to improve priority setting methods, The Child Health and Nutrition Research Initiative (CHNRI has developed a common framework to score competing interventions into child health. That framework involves the assessment of 12 different criteria upon which interventions can be compared. This report follows the proposed framework, using a semi-systematic literature review and the results of a structured exercise gathering opinion from experts (leading basic scientists, international public health researchers, international policy makers and representatives of pharmaceutical companies, to assess and score each criterion as their “collective optimism” towards each, on a scale from 0 to 100%. Results A rough estimate from an analysis of the literature suggests that global strengthening of oxygen systems could save lives of up to 122,000 children from pneumonia annually. Following 12 CHNRI criteria, the experts expressed very high levels of optimism (over 80% for answerability, low development cost and low product cost; high levels of optimism (60-80% for low implementation cost, likelihood of efficacy, deliverability, acceptance to end users and health workers; and moderate levels of optimism (40-60% for impact on equity, affordability and sustainability. The median estimate of potential effectiveness of oxygen systems to reduce the overall childhood pneumonia mortality was ~20% (interquartile range: 10-35%, min

Effect of oxygen defects on transport properties and Tc of YBa2Cu3O6+x: Displacement energy for plane and chain oxygen and implications for irradiation-induced resistivity and Tc suppression

International Nuclear Information System (INIS)

Tolpygo, S.K.; Lin, J.; Gurvitch, M.; Hou, S.Y.; Phillips, J.M.

1996-01-01

The effect of electron irradiation with energy from 20 to 120 keV on the resistivity, Hall coefficient, and superconducting critical temperature T c of YBa 2 Cu 3 O 6+x thin films has been studied. The threshold energy of incident electrons for T c suppression has been found, and the displacement energy for oxygen in CuO 2 planes has been evaluated as 8.4 eV for irradiation along the c axis. The kinetics of production of the in-plane oxygen vacancies has been studied and found to be governed by athermal recombination of vacancy-interstitial pairs. The evaluated recombination volume constitutes about 21 unit cells. The increase in the T-linear resistivity slope and Hall coefficient at unchanged T c was observed in irradiations with subthreshold incident energies and was ascribed to the effect of chain oxygen displacements. The upper limit on the displacement energy for chain oxygen has been estimated as 2.8 eV. In x=0.9 samples the T c suppression by in-plane oxygen defects and increase in residual resistivity have been found to be, respectively, -280 K and 1.5 mΩcm per defect in the unit cell. It is shown that T c suppression by in-plane oxygen defects is a universal function of the transport impurity scattering rate and can be described qualitatively by pair-breaking theory for d-wave superconductors with nonmagnetic potential scatterers. Evaluation of scattering and pair-breaking rates as well as the scattering cross section and potential is given. A comparison of the influence of in-plane oxygen defects on transport properties with that of other in-plane defects, such as Zn and Ni substitutions for Cu, is also made. copyright 1996 The American Physical Society

Microcomputer-based system for registration of oxygen tension in peripheral muscle.

Science.gov (United States)

Odman, S; Bratt, H; Erlandsson, I; Sjögren, L

1986-01-01

For registration of oxygen tension fields in peripheral muscle a microcomputer based system was designed on the M6800 microprocessor. The system was designed to record the signals from a multiwire oxygen electrode, MDO, which is a multiwire electrode for measuring oxygen on the surface of an organ. The system contained patient safety isolation unit built on optocopplers and the upper frequency limit was 0.64 Hz. Collected data were corrected for drift and temperature changes during the measurement by using pre- and after calibrations and a linear compensation technique. Measure drift of the electrodes were proved to be linear and thus the drift could be compensated for. The system was tested in an experiment on pig. To study the distribution of oxygen statistically mean, standard deviation, skewness and curtosis were calculated. To see changes or differences between histograms a Kolmogorv-Smirnov test was used.

Evaluation of intelligent transport systems impact on school transport safety

Directory of Open Access Journals (Sweden)

Jankowska-Karpa Dagmara

2017-01-01

Full Text Available The integrated system of safe transport of children to school using Intelligent Transport Systems was developed and implemented in four locations across Europe under the Safeway2School (SW2S project, funded by the EU. The SW2S system evaluation included speed measurements and an eye-tracking experiment carried out among drivers who used the school bus route, where selected elements of the system were tested. The subject of the evaluation were the following system elements: pedestrian safety system at the bus stop (Intelligent Bus Stop and tags for children, Driver Support System, applications for parents’ and students’ mobile phones, bus stop inventory tool and data server. A new sign designed for buses and bus stops to inform about child transportation/children waiting at the bus stop was added to the system. Training schemes for system users were also provided. The article presents evaluation results of the impact of selected elements of the SW2S system on school transport safety in Poland.

Transportable criticality alarm system

International Nuclear Information System (INIS)

Clem, W.E.

1988-09-01

The Transportable Criticality Alarm System was developed at the Hanford Site in 1982 to comply with the requirements of US Department of Energy Order DOE 5480.1, 12/18/80, and ANSI/ANS-8.3- 1979. The portable unit that it replaced failed to comply with the new requirements in that it did not provide the necessary warning of malfunctions, nor did it provide the Hanford Site standard criticality alarm signal. Modern technology allowed the Transportable Criticality Alarm System to comply with the criticality requirements cited and to incorporate other features that make it more usable, maintainable, and reliable. The Transportable Criticality Alarm System (TCAS) provides temporary criticality coverage in manned areas where the facility criticality alarm system is not operable. This gamma radiation-sensitive system has been in use for the past 6 yr at the Hanford Site. 2 refs., 4 figs., 1 tab

Interfacial microstructure and shear strength of reactive air brazed oxygen transport membrane ceramic-metal alloy joints

Science.gov (United States)

FR, Wahid Muhamad; Yoon, Dang-Hyok; Raju, Kati; Kim, Seyoung; Song, Kwang-sup; Yu, Ji Haeng

2018-01-01

To fabricate a multi-layered structure for maximizing oxygen production, oxygen transport membrane (OTM) ceramics need to be joined or sealed hermetically metal supports for interfacing with the peripheral components of the system. Therefore, in this study, Ag-10 wt% CuO was evaluated as an effective filler material for the reactive air brazing of dense Ce0.9Gd0.1O2-δ-La0.7Sr0.3MnO3±δ (GDC-LSM) OTM ceramics. Thermal decomposition in air and wetting behavior of the braze filler was performed. Reactive air brazing was performed at 1050 °C for 30 min in air to join GDC-LSM with four different commercially available high temperature-resistant metal alloys, such as Crofer 22 APU, Inconel 600, Fecralloy, and AISI 310S. The microstructure and elemental distribution of the ceramic-ceramic and ceramic-metal interfaces were examined from polished cross-sections. The mechanical shear strength at room temperature for the as-brazed and isothermally aged (800 °C for 24 h) joints of all the samples was compared. The results showed that the strength of the ceramic-ceramic joints was decreased marginally by aging; however, in the case of metal-ceramic joints, different decreases in strengths were observed according to the metal alloy used, which was explained based on the formation of different oxide layers at the interfaces.

The effect of topological defects and oxygen adsorption on the electronic transport properties of single-walled carbon-nanotubes

International Nuclear Information System (INIS)

Grujicic, M.; Cao, G.; Singh, R.

2003-01-01

Ab initio density functional theory (DFT) calculations of the interactions between isolated infinitely-long semiconducting zig-zag (10, 0) or isolated infinitely-long metallic arm-chair (5, 5) single-walled carbon-nanotubes (SWCNTs) and single oxygen-molecules are carried out in order to determine the character of molecular-oxygen adsorption and its effect on electronic transport properties of these SWCNTs. A Green's function method combined with a nearest-neighbor tight-binding Hamiltonian in a non-orthogonal basis is used to compute the electrical conductance of SWCNTs and its dependence on the presence of topological defects in SWCNTs and of molecular-oxygen adsorbates. The computational results obtained show that in both semiconducting and metallic SWCNTs, oxygen-molecules are physisorbed to the defect-free nanotube walls, but when such walls contain topological defects, oxygen-molecules become strongly chemisorbed. In semiconducting (10, 0) SWCNTs, physisorbed O 2 -molecules are found to significantly increase electrical conductance while the effect of 7-5-5-7 defects is practically annulled by chemisorbed O 2 -molecules. In metallic (5, 5) SWCNTs, both O 2 adsorbates and 7-5-5-7 defects are found to have a relatively small effect on electrical conductance of these nanotubes

Evaluation of alternative public transportation systems in Izmit urban transportation via axiomatic design method

Directory of Open Access Journals (Sweden)

Gülşen AKMAN

2016-02-01

Full Text Available In the world and in our country, most of urban transportation is performed by public transportation. Public transportation is a system which provides transportation easiness and opportunity to people, not to vehicles. Therefore, giving priority to public transportation system is necessary in organizing urban transportation. In this study, in order to reduce traffic intensity and to facilitate passenger transportation in Izmit urban transportation, It is tried to determine appropriate public transportation system. For this, firstly, alternatives which could be used for public transportation were determined. These alternatives are metro, metrobus, tram, light rail system and monorail. Afterwards, the variables affecting decision making about public transportation were determined. These variables are cost, transportation line features, vehicle characteristics, sensitivity to environment and customer satisfaction. Lastly, most appropriate public transportation system is proposed by using the axiomatic design method. As a result, light trail system and metrobus are determined as the most appropriate alternatives for Izmit public transportation system.Keywords: Urban transportation, Multi criteria decision making, Axiomatic design

49 CFR 37.25 - University transportation systems.

Science.gov (United States)

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false University transportation systems. 37.25 Section 37.25 Transportation Office of the Secretary of Transportation TRANSPORTATION SERVICES FOR INDIVIDUALS WITH DISABILITIES (ADA) Applicability § 37.25 University transportation systems. (a...

Effect of hydrophobic additive on oxygen transport in catalyst layer of proton exchange membrane fuel cells

Science.gov (United States)

Wang, Shunzhong; Li, Xiaohui; Wan, Zhaohui; Chen, Yanan; Tan, Jinting; Pan, Mu

2018-03-01

Oxygen transport resistance (OTR) is a critical factor influencing the performance of proton exchange membrane fuel cells (PEMFCs). In this paper, an effective method to reduce the OTR of catalyst layers (CLs) by introducing a hydrophobic additive into traditional CLs is proposed. A low-molecular-weight polytetrafluoroethylene (PTFE) is selected for its feasibility to prepare an emulsion, which is mixed with a traditional catalyst ink to successfully fabricate the CL with PTFE of 10 wt%. The PTFE film exists in the mesopores between the carbon particles. The limiting current of the hydrophobic CL was almost 4000 mA/cm2, which is 500 mA/cm2 higher than that of the traditional CL. PTFE reduces the OTR of the CL in the dry region by as much as 24 s/m compared to the traditional CL and expands the dry region from 2000 mA/cm2 in the traditional CL to 2500 mA/cm2. Furthermore, the CL with the hydrophobic agent can improve the oxygen transport in the wet region (>2000 mA/cm2) more effectively than that in the dry region. All these results indicate that the CL with the hydrophobic agent shows a superior performance in terms of optimizing water management and effectively reduces the OTR in PEMFCs.

The WIPP transportation system: Demonstrated readiness

International Nuclear Information System (INIS)

Ward, T.R.; Spooner, R.

1991-01-01

The Department of Energy (DOE) has developed an integrated transportation system to transport transuranic (TRU) waste from ten widely-dispersed generator sites to the Waste Isolation Pilot Plant (WIPP). The system consists of a Type B container, a specially- designed trailer, a lightweight tractor, the DOE ''TRANSCOM'' vehicle tracking system, and uniquely qualified and highly-trained drivers. In June of 1989, the National Academy of Sciences reviewed the transportation system and concluded that: ''The system proposed for transportation of TRU waste to WIPP is safer than that employed for any other hazardous material in the United States today and will reduce risk to very low levels'' (emphasis added). The next challenge facing the DOE was demonstrating that this system was ready to transport the TRU waste to the WIPP site efficiently and in the safest manner possible. Not only did the DOE feel that is was necessary to convince itself that the system was safe, but also representatives of the 20 states through which it would travel

The WIPP transportation system: Demonstrated readiness

International Nuclear Information System (INIS)

Ward, T.R.; Spooner, R.

1991-01-01

The Department of Energy (DOE) has developed an integrated transportation system to transport transuranic (TRU) waste from ten widely-dispersed generator sites to the Waste Isolation Pilot Plant (WIPP). The system consists of a Type B container, a specially-designed trailer, a lightweight tractor, the DOE ''TRANSCOM'' vehicle tracing system, and uniquely qualified and highly-trained drivers. In June of 1989, the National Academy of Sciences reviewed the transportation system and concluded that: ''The system proposed for transportation of TRU waste to WIPP is safer than that employed for any other hazardous material in the United States today and will reduce risk to very low levels.'' The next challenge facing the DOE was demonstrating that this system was ready to transport the TRU waste to the WIPP site in the safest manner possible. Not only did the DOE feel that it was necessary to convince itself that the system was safe, but also representatives of the 23 states through which it traveled

Phenotypic plasticity in blood–oxygen transport in highland and lowland deer mice

Science.gov (United States)

Tufts, Danielle M.; Revsbech, Inge G.; Cheviron, Zachary A.; Weber, Roy E.; Fago, Angela; Storz, Jay F.

2013-01-01

SUMMARY In vertebrates living at high altitude, arterial hypoxemia may be ameliorated by reversible changes in the oxygen-carrying capacity of the blood (regulated by erythropoiesis) and/or changes in blood–oxygen affinity (regulated by allosteric effectors of hemoglobin function). These hematological traits often differ between taxa that are native to different elevational zones, but it is often unknown whether the observed physiological differences reflect fixed, genetically based differences or environmentally induced acclimatization responses (phenotypic plasticity). Here, we report measurements of hematological traits related to blood–O2 transport in populations of deer mice (Peromyscus maniculatus) that are native to high- and low-altitude environments. We conducted a common-garden breeding experiment to assess whether altitude-related physiological differences were attributable to developmental plasticity and/or physiological plasticity during adulthood. Under conditions prevailing in their native habitats, high-altitude deer mice from the Rocky Mountains exhibited a number of pronounced hematological differences relative to low-altitude conspecifics from the Great Plains: higher hemoglobin concentrations, higher hematocrits, higher erythrocytic concentrations of 2,3-diphosphoglycerate (an allosteric regulator of hemoglobin–oxygen affinity), lower mean corpuscular hemoglobin concentrations and smaller red blood cells. However, these differences disappeared after 6 weeks of acclimation to normoxia at low altitude. The measured traits were also indistinguishable between the F1 progeny of highland and lowland mice, indicating that there were no persistent differences in phenotype that could be attributed to developmental plasticity. These results indicate that the naturally occurring hematological differences between highland and lowland mice are environmentally induced and are largely attributable to physiological plasticity during adulthood. PMID

Oxygen Transport Ceramic Membranes

Energy Technology Data Exchange (ETDEWEB)

S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

2004-05-01

the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

A National MagLev Transportation System

Science.gov (United States)

Wright, Michael R.

2003-01-01

The case for a national high-speed magnetic-levitation (MagLev) transportation system is presented. Focus is on current issues facing the country, such as national security, the economy, transportation, technology, and the environment. NASA s research into MagLev technology for launch assist is also highlighted. Further, current socio-cultural norms regarding motor-vehicle-based transportation systems are questioned in light of the problems currently facing the U.S. The multidisciplinary benefits of a long-distance MagLev system support the idea that such a system would be an important element of a truly multimodal U.S. transportation infrastructure.

The Profile of Student Misconceptions on The Human and Plant Transport Systems

Science.gov (United States)

Ainiyah, M.; Ibrahim, M.; Hidayat, M. T.

2018-01-01

This research aims to identify misconceptions on the humans and plants transportation systems. The research was done in the 8th grade in Indonesia. Data were collected to use a three-tier test. This type of research was used survey design. Content analysis was used to analyze the misconception data. The results of this research were the location of misconception of each student is different. The highest misconceptions identified in this research, namely: a) arteries that drain blood to the heart (73.3%); b) veins that drain blood from the heart (70.0%); c) place of oxygen and carbon dioxide exchange occurs in the veins (66.7%); d) blood pressure in veins greater than in capillaries (63.3%); e) absorption of water occurs diffusion and absorption of minerals occurs osmosis (76.7%); f) transport of photosynthesis process occurs by diffusion (66.7%); g) photosynthesis process occurs during the day (63.3%); and h) process of evaporation of water through the leaves are guttation (56.7%). The results of this research show that the level of students misconceptions on the of human and plant transport systems is still high so that it can serve as a reference to improve the learning process and the reduction of student misconceptions.

Textile Inspired Lithium-Oxygen Battery Cathode with Decoupled Oxygen and Electrolyte Pathways.

Science.gov (United States)

Xu, Shaomao; Yao, Yonggang; Guo, Yuanyuan; Zeng, Xiaoqiao; Lacey, Steven D; Song, Huiyu; Chen, Chaoji; Li, Yiju; Dai, Jiaqi; Wang, Yanbin; Chen, Yanan; Liu, Boyang; Fu, Kun; Amine, Khalil; Lu, Jun; Hu, Liangbing

2018-01-01

The lithium-air (Li-O 2 ) battery has been deemed one of the most promising next-generation energy-storage devices due to its ultrahigh energy density. However, in conventional porous carbon-air cathodes, the oxygen gas and electrolyte often compete for transport pathways, which limit battery performance. Here, a novel textile-based air cathode is developed with a triple-phase structure to improve overall battery performance. The hierarchical structure of the conductive textile network leads to decoupled pathways for oxygen gas and electrolyte: oxygen flows through the woven mesh while the electrolyte diffuses along the textile fibers. Due to noncompetitive transport, the textile-based Li-O 2 cathode exhibits a high discharge capacity of 8.6 mAh cm -2 , a low overpotential of 1.15 V, and stable operation exceeding 50 cycles. The textile-based structure can be applied to a range of applications (fuel cells, water splitting, and redox flow batteries) that involve multiple phase reactions. The reported decoupled transport pathway design also spurs potential toward flexible/wearable Li-O 2 batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of an oxygen saturation measuring system by using near-infrared spectroscopy

Science.gov (United States)

Kono, K.; Nakamachi, E.; Morita, Y.

2017-08-01

Recently, the hypoxia imaging has been recognized as the advanced technique to detect cancers because of a strong relationship with the biological characterization of cancer. In previous studies, hypoxia imaging systems for endoscopic diagnosis have been developed. However, these imaging technologies using the visible light can observe only blood vessels in gastric mucous membrane. Therefore, they could not detect scirrhous gastric cancer which accounts for 10% of all gastric cancers and spreads rapidly into submucous membrane. To overcome this problem, we developed a measuring system of blood oxygen saturation in submucous membrane by using near-infrared (NIR) spectroscopy. NIR, which has high permeability for bio-tissues and high absorbency for hemoglobin, can image and observe blood vessels in submucous membrane. NIR system with LED lights and a CCD camera module was developed to image blood vessels. We measured blood oxygen saturation using the optical density ratio (ODR) of two wavelengths, based on Lambert-Beer law. To image blood vessel clearly and measure blood oxygen saturation accurately, we searched two optimum wavelengths by using a multilayer human gastric-like phantom which has same optical properties as human gastric one. By using Monte Carlo simulation of light propagation, we derived the relationship between the ODR and blood oxygen saturation and elucidated the influence of blood vessel depth on measuring blood oxygen saturation. The oxygen saturation measuring methodology was validated with experiments using our NIR system. Finally, it was confirmed that our system can detect oxygen saturation in various depth blood vessels accurately.

Oxygen doping of the high T/sub c/ superconducting perovskites

International Nuclear Information System (INIS)

Tarascon, J.M.; McKinnon, W.R.; Greene, L.H.; Hull, G.W.; Bagley, B.G.; Vogel, E.M.; Le Page, Y.

1987-01-01

Oxygen defect perovskites are studied because of their ability to reversibly intercalate oxygen atoms. Our previous studies of the La/sub 2-y/Sr/sub y/CuO/sub 4-x/ system shows that T/sub c/ is dramatically affected by subtle changes in oxygen content. However since this study did not achieve large values of x, a systematic study was not undertaken. The authors have found by thermogravimetric analysis (TGA) that a wide range of oxygen non-stoichiometry in the 90K superconductor YBa/sub 2/Cu/sub 3/O/sub 7-x/ is obtainable. This study of the effect of oxygen doping on the transport properties of the 40K material, and a systematic analysis of this over a broader range in the 90K superconductor is presented

METHODS OF INTEGRATED OPTIMIZATION MAGLEV TRANSPORT SYSTEMS

Directory of Open Access Journals (Sweden)

A. Lasher

2013-09-01

Full Text Available Purpose. To demonstrate feasibility of the proposed integrated optimization of various MTS parameters to reduce capital investments as well as decrease any operational and maintenance expense. This will make use of MTS reasonable. At present, the Maglev Transport Systems (MTS for High-Speed Ground Transportation (HSGT almost do not apply. Significant capital investments, high operational and maintenance costs are the main reasons why Maglev Transport Systems (MTS are hardly currently used for the High-Speed Ground Transportation (HSGT. Therefore, this article justifies use of Theory of Complex Optimization of Transport (TCOT, developed by one of the co-authors, to reduce MTS costs. Methodology. According to TCOT, authors developed an abstract model of the generalized transport system (AMSTG. This model mathematically determines the optimal balance between all components of the system and thus provides the ultimate adaptation of any transport systems to the conditions of its application. To identify areas for effective use of MTS, by TCOT, the authors developed a dynamic model of distribution and expansion of spheres of effective use of transport systems (DMRRSEPTS. Based on this model, the most efficient transport system was selected for each individual track. The main estimated criterion at determination of efficiency of application of MTS is the size of the specific transportation tariff received from calculation of payback of total given expenses to a standard payback period or term of granting the credit. Findings. The completed multiple calculations of four types of MTS: TRANSRAPID, MLX01, TRANSMAG and TRANSPROGRESS demonstrated efficiency of the integrated optimization of the parameters of such systems. This research made possible expending the scope of effective usage of MTS in about 2 times. The achieved results were presented at many international conferences in Germany, Switzerland, United States, China, Ukraine, etc. Using MTS as an

Impact of thermal conductivity models on the coupling of heat transport, oxygen diffusion, and deformation in (U, Pu)O nuclear fuel elements

Science.gov (United States)

Mihaila, Bogdan; Stan, Marius; Crapps, Justin; Yun, Di

2013-02-01

We study the coupled thermal transport, oxygen diffusion, and thermal expansion in a generic nuclear fuel rod consisting of a (U) fuel pellet separated by a helium gap from zircaloy cladding. Steady-state and time-dependent finite-element simulations with a variety of initial- and boundary-value conditions are used to study the effect of the Pu content, y, and deviation from stoichiometry, x, on the temperature and deformation profiles in this fuel element. We find that the equilibrium radial temperature and deformation profiles are most sensitive to x at small values of y. For larger values of y, the effects of oxygen and Pu content are equally important. Following a change in the heat-generation rate, the centerline temperature, the radial deformation of the fuel pellet, and the centerline deviation from stoichiometry track each other closely in (U,Pu)O, as the characteristic time scales of the heat transport and oxygen diffusion are similar. This result is different from the situation observed in the case of UO fuels.

A computational model for simulating solute transport and oxygen consumption along the nephrons

Science.gov (United States)

Vallon, Volker; Edwards, Aurélie

2016-01-01

The goal of this study was to investigate water and solute transport, with a focus on sodium transport (TNa) and metabolism along individual nephron segments under differing physiological and pathophysiological conditions. To accomplish this goal, we developed a computational model of solute transport and oxygen consumption (QO2) along different nephron populations of a rat kidney. The model represents detailed epithelial and paracellular transport processes along both the superficial and juxtamedullary nephrons, with the loop of Henle of each model nephron extending to differing depths of the inner medulla. We used the model to assess how changes in TNa may alter QO2 in different nephron segments and how shifting the TNa sites alters overall kidney QO2. Under baseline conditions, the model predicted a whole kidney TNa/QO2, which denotes the number of moles of Na+ reabsorbed per moles of O2 consumed, of ∼15, with TNa efficiency predicted to be significantly greater in cortical nephron segments than in medullary segments. The TNa/QO2 ratio was generally similar among the superficial and juxtamedullary nephron segments, except for the proximal tubule, where TNa/QO2 was ∼20% higher in superficial nephrons, due to the larger luminal flow along the juxtamedullary proximal tubules and the resulting higher, flow-induced transcellular transport. Moreover, the model predicted that an increase in single-nephron glomerular filtration rate does not significantly affect TNa/QO2 in the proximal tubules but generally increases TNa/QO2 along downstream segments. The latter result can be attributed to the generally higher luminal [Na+], which raises paracellular TNa. Consequently, vulnerable medullary segments, such as the S3 segment and medullary thick ascending limb, may be relatively protected from flow-induced increases in QO2 under pathophysiological conditions. PMID:27707705

Control of oxygen tension recapitulates zone-specific functions in human liver microphysiology systems.

Science.gov (United States)

Lee-Montiel, Felipe T; George, Subin M; Gough, Albert H; Sharma, Anup D; Wu, Juanfang; DeBiasio, Richard; Vernetti, Lawrence A; Taylor, D Lansing

2017-10-01

This article describes our next generation human Liver Acinus MicroPhysiology System (LAMPS). The key demonstration of this study was that Zone 1 and Zone 3 microenvironments can be established by controlling the oxygen tension in individual devices over the range of ca. 3 to 13%. The oxygen tension was computationally modeled using input on the microfluidic device dimensions, numbers of cells, oxygen consumption rates of hepatocytes, the diffusion coefficients of oxygen in different materials and the flow rate of media in the MicroPhysiology System (MPS). In addition, the oxygen tension was measured using a ratiometric imaging method with the oxygen sensitive dye, Tris(2,2'-bipyridyl) dichlororuthenium(II) hexahydrate (RTDP) and the oxygen insensitive dye, Alexa 488. The Zone 1 biased functions of oxidative phosphorylation, albumin and urea secretion and Zone 3 biased functions of glycolysis, α1AT secretion, Cyp2E1 expression and acetaminophen toxicity were demonstrated in the respective Zone 1 and Zone 3 MicroPhysiology System. Further improvements in the Liver Acinus MicroPhysiology System included improved performance of selected nonparenchymal cells, the inclusion of a porcine liver extracellular matrix to model the Space of Disse, as well as an improved media to support both hepatocytes and non-parenchymal cells. In its current form, the Liver Acinus MicroPhysiology System is most amenable to low to medium throughput, acute through chronic studies, including liver disease models, prioritizing compounds for preclinical studies, optimizing chemistry in structure activity relationship (SAR) projects, as well as in rising dose studies for initial dose ranging. Impact statement Oxygen zonation is a critical aspect of liver functions. A human microphysiology system is needed to investigate the impact of zonation on a wide range of liver functions that can be experimentally manipulated. Because oxygen zonation has such diverse physiological effects in the liver, we

Ketosis After Cardiopulmonary Bypass in Children Is Associated With an Inadequate Balance Between Oxygen Transport and Consumption.

Science.gov (United States)

Klee, Philippe; Arni, Delphine; Saudan, Sonja; Schwitzgebel, Valérie M; Sharma, Ruchika; Karam, Oliver; Rimensberger, Peter C

2016-09-01

Hyperglycemia after cardiac surgery and cardiopulmonary bypass in children has been associated with worse outcome; however, causality has never been proven. Furthermore, the benefit of tight glycemic control is inconsistent. The purpose of this study was to describe the metabolic constellation of children before, during, and after cardiopulmonary bypass, in order to identify a subset of patients that might benefit from insulin treatment. Prospective observational study, in which insulin treatment was initiated when postoperative blood glucose levels were more than 12 mmol/L (216 mg/dL). Tertiary PICU. Ninety-six patients 6 months to 16 years old undergoing cardiac surgery with cardiopulmonary bypass. None. Metabolic tests were performed before anesthesia, at the end of cardiopulmonary bypass, at PICU admission, and 4 and 12 hours after PICU admission, as well as 4 hours after initiation of insulin treatment. Ketosis was present in 17.9% patients at the end of cardiopulmonary bypass and in 31.2% at PICU admission. Young age was an independent risk factor for this condition. Ketosis at PICU admission was an independent risk factor for an increased difference between arterial and venous oxygen saturation. Four hours after admission (p = 0.05). Insulin corrected ketosis within 4 hours. In this study, we found a high prevalence of ketosis at PICU admission, especially in young children. This was independently associated with an imbalance between oxygen transport and consumption and was corrected by insulin. These results set the basis for future randomized controlled trials, to test whether this subgroup of patients might benefit from increased glucose intake and insulin during surgery to avoid ketosis, as improving oxygen transport and consumption might improve patient outcome.

Integrated transport and renewable energy systems

DEFF Research Database (Denmark)

Mathiesen, Brian Vad; Lund, Henrik; Nørgaard, P.

2008-01-01

No single technology can solve the problem of ever increasing CO2 emissions from transport. Here, a coherent effort to integrate transport into energyplanning is proposed, using multiple means promoting sustainable transport. It is concluded that a 100 per cent renewable energy transport system...... is possible but is connected to significant challenges in the path towards it. Biomass is a limited resource and it is important to avoid effecting the production of food. The integration of the transport with the energy system is crucial as is a multi-pronged strategy. Short term solutions have to consider...

Sensor Technologies for Intelligent Transportation Systems.

Science.gov (United States)

Guerrero-Ibáñez, Juan; Zeadally, Sherali; Contreras-Castillo, Juan

2018-04-16

Modern society faces serious problems with transportation systems, including but not limited to traffic congestion, safety, and pollution. Information communication technologies have gained increasing attention and importance in modern transportation systems. Automotive manufacturers are developing in-vehicle sensors and their applications in different areas including safety, traffic management, and infotainment. Government institutions are implementing roadside infrastructures such as cameras and sensors to collect data about environmental and traffic conditions. By seamlessly integrating vehicles and sensing devices, their sensing and communication capabilities can be leveraged to achieve smart and intelligent transportation systems. We discuss how sensor technology can be integrated with the transportation infrastructure to achieve a sustainable Intelligent Transportation System (ITS) and how safety, traffic control and infotainment applications can benefit from multiple sensors deployed in different elements of an ITS. Finally, we discuss some of the challenges that need to be addressed to enable a fully operational and cooperative ITS environment.

Sensor Technologies for Intelligent Transportation Systems

Science.gov (United States)

Guerrero-Ibáñez, Juan; Zeadally, Sherali

2018-01-01

Modern society faces serious problems with transportation systems, including but not limited to traffic congestion, safety, and pollution. Information communication technologies have gained increasing attention and importance in modern transportation systems. Automotive manufacturers are developing in-vehicle sensors and their applications in different areas including safety, traffic management, and infotainment. Government institutions are implementing roadside infrastructures such as cameras and sensors to collect data about environmental and traffic conditions. By seamlessly integrating vehicles and sensing devices, their sensing and communication capabilities can be leveraged to achieve smart and intelligent transportation systems. We discuss how sensor technology can be integrated with the transportation infrastructure to achieve a sustainable Intelligent Transportation System (ITS) and how safety, traffic control and infotainment applications can benefit from multiple sensors deployed in different elements of an ITS. Finally, we discuss some of the challenges that need to be addressed to enable a fully operational and cooperative ITS environment. PMID:29659524

Sensor Technologies for Intelligent Transportation Systems

Directory of Open Access Journals (Sweden)

Juan Guerrero-Ibáñez

2018-04-01

Full Text Available Modern society faces serious problems with transportation systems, including but not limited to traffic congestion, safety, and pollution. Information communication technologies have gained increasing attention and importance in modern transportation systems. Automotive manufacturers are developing in-vehicle sensors and their applications in different areas including safety, traffic management, and infotainment. Government institutions are implementing roadside infrastructures such as cameras and sensors to collect data about environmental and traffic conditions. By seamlessly integrating vehicles and sensing devices, their sensing and communication capabilities can be leveraged to achieve smart and intelligent transportation systems. We discuss how sensor technology can be integrated with the transportation infrastructure to achieve a sustainable Intelligent Transportation System (ITS and how safety, traffic control and infotainment applications can benefit from multiple sensors deployed in different elements of an ITS. Finally, we discuss some of the challenges that need to be addressed to enable a fully operational and cooperative ITS environment.

Replacement of HCFC-225 Solvent for Cleaning NASA Propulsion Oxygen Systems

Science.gov (United States)

Mitchell, Mark A.; Lowrey, Nikki M.

2015-01-01

Since the 1990's, when the Class I Ozone Depleting Substance (ODS) chlorofluorocarbon-113 (CFC-113) was banned, NASA's rocket propulsion test facilities at Marshall Space Flight Center (MSFC) and Stennis Space Center (SSC) have relied upon hydrochlorofluorocarbon-225 (HCFC-225) to safely clean and verify the cleanliness of large scale propulsion oxygen systems. Effective January 1, 2015, the production, import, export, and new use of HCFC-225, a Class II ODS, was prohibited by the Clean Air Act. In 2012 through 2014, leveraging resources from both the NASA Rocket Propulsion Test Program and the Defense Logistics Agency - Aviation Hazardous Minimization and Green Products Branch, test labs at MSFC, SSC, and Johnson Space Center's White Sands Test Facility (WSTF) collaborated to seek out, test, and qualify a replacement for HCFC-225 that is both an effective cleaner and safe for use with oxygen systems. Candidate solvents were selected and a test plan was developed following the guidelines of ASTM G127, Standard Guide for the Selection of Cleaning Agents for Oxygen Systems. Solvents were evaluated for materials compatibility, oxygen compatibility, cleaning effectiveness, and suitability for use in cleanliness verification and field cleaning operations. Two solvents were determined to be acceptable for cleaning oxygen systems and one was chosen for implementation at NASA's rocket propulsion test facilities. The test program and results are summarized. This project also demonstrated the benefits of cross-agency collaboration in a time of limited resources.

Design and optimization of porous ceramic supports for asymmetric ceria-based oxygen transport membranes

DEFF Research Database (Denmark)

Kaiser, Andreas; Foghmoes, Søren Preben Vagn; Pećanac, G.

2016-01-01

The microstructure, mechanical properties and gas permeability of porous supports of Ce0.9Gd0.1O1.95−δ (CGO) were investigated as a function of sintering temperature and volume fraction of pore former for use in planar asymmetric oxygen transport membranes (OTMs). With increasing the pore former...... content from 11 vol% to 16 vol%, the gas permeabilities increased by a factor of 5 when support tapes were sintered to comparable densities. The improved permeabilities were due to a more favourable microstructure with larger interconnected pores at a porosity of 45% and a fracture strength of 47±2 MPa (m...

Transport properties of water and oxygen in yttria-stabilized zirconia; Transporteigenschaften von Wasser und Sauerstoff in Yttrium-stabilisiertem Zirkoniumdioxid

Energy Technology Data Exchange (ETDEWEB)

Pietrowski, Martha Joanna

2012-12-21

Oxide materials that adopt the fluorite structure, such as yttria-stabilized zirconia (YSZ), play a central role in electrochemical devices, such as fuel cells and sensors, because of their high ionic conductivity. By virtue of the technological importance of such devices there exists a broad interest in understanding and enhancing mass transport processes in YSZ. In such oxides, not only does transport through the bulk play a critical role; interfaces (internal and external) have an influence, too. The effect of interfaces on the transport properties, however, is not investigated in detail, and remains in many places unclear. In this work two open questions concerning the effect of interfaces on mass transport processes in YSZ are addressed: The first issue is the phenomenon of protonic conductivity observed at low temperatures for nanocrystalline YSZ in wet atmospheres. This protonic conductivity was attributed to the high density of interfaces (grain boundaries) caused by the nanostructure, in which protonic species can be mobile. Through isotope exchange experiments with subsequent Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) the presence of hydrogen in nano-YSZ was confirmed. Questions as to which hydrogen-containing species are present and which transport path is taken in nanocrystalline YSZ were examined by means of in-situ of near-infrared (NIR) spectroscopy. The results indicate that water is adsorbed on internal surfaces, such as pores and micro-cracks. Microscopic analysis of nanocrystalline YSZ showed first indications of nanopores. The second issue concerned transport across the solidgas interface, that is the surface. To this end, oxygen isotope exchange experiments were performed on single crystal samples of yttria-stabilised zirconia under wet and dry conditions as function of oxygen partial pressure pO{sub 2} and water partial pressure pH{sub 2}O with subsequent determination of the oxygen isotope profiles by ToF-SIMS. As expected, the

Factors Determining the Oxygen Permeability of Biological Membranes: Oxygen Transport Across Eye Lens Fiber-Cell Plasma Membranes.

Science.gov (United States)

Subczynski, Witold Karol; Widomska, Justyna; Mainali, Laxman

2017-01-01

Electron paramagnetic resonance (EPR) spin-label oximetry allows the oxygen permeability coefficient to be evaluated across homogeneous lipid bilayer membranes and, in some cases, across coexisting membrane domains without their physical separation. The most pronounced effect on oxygen permeability is observed for cholesterol, which additionally induces the formation of membrane domains. In intact biological membranes, integral proteins induce the formation of boundary and trapped lipid domains with a low oxygen permeability. The effective oxygen permeability coefficient across the intact biological membrane is affected not only by the oxygen permeability coefficients evaluated for each lipid domain but also by the surface area occupied by these domains in the membrane. All these factors observed in fiber cell plasma membranes of clear human eye lenses are reviewed here.

The transportation operations system: A description

International Nuclear Information System (INIS)

Best, R.E.; Danese, F.L.; Dixon, L.D.; Peterson, R.W.; Pope, R.B.

1990-01-01

This paper presents a description of the system for transporting radioactive waste that may be deployed to accomplish the assigned system mission, which includes accepting spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from waste generator sites and transporting them to the FWMS destination facilities. The system description presented here contains, in part, irradiated fuel and waste casks, ancillary equipments, truck, rail, and barge transporters, cask and vehicle traffic management organizations, maintenance facilities, and other operations elements. The description is for a fully implemented system, which is not expected to be achieved, however, until several years after initial operations. 6 figs

Radioisotope Thermoelectric Generator Transport Trailer System

International Nuclear Information System (INIS)

Ard, K.E.; King, D.A.; Leigh, H.; Satoh, J.A.

1994-01-01

The Radioisotope Thermoelectric Generator (RTG) Transportation System, designated as System 100, comprises four major systems. The four major systems are designated as the Packaging System (System 120), Trailer System (System 140), Operations and Ancillary Equipment System system 160), and Shipping and Receiving Facility Transport System (System 180). Packaging System (System 120), including the RTG packaging is licensed (regulatory) hardware; it is certified by the US Department of Energy to be in accordance with Title 10, Code of federal Regulations, Part 71 (10 CFR 71). System 140, System 160, and System 180 are nonlicensed (nonregulatory) hardware

Comparative genomic analyses of copper transporters and cuproproteomes reveal evolutionary dynamics of copper utilization and its link to oxygen.

Directory of Open Access Journals (Sweden)

Perry G Ridge

2008-01-01

Full Text Available Copper is an essential trace element in many organisms and is utilized in all domains of life. It is often used as a cofactor of redox proteins, but is also a toxic metal ion. Intracellular copper must be carefully handled to prevent the formation of reactive oxygen species which pose a threat to DNA, lipids, and proteins. In this work, we examined patterns of copper utilization in prokaryotes by analyzing the occurrence of copper transporters and copper-containing proteins. Many organisms, including those that lack copper-dependent proteins, had copper exporters, likely to protect against copper ions that inadvertently enter the cell. We found that copper use is widespread among prokaryotes, but also identified several phyla that lack cuproproteins. This is in contrast to the use of other trace elements, such as selenium, which shows more scattered and reduced usage, yet larger selenoproteomes. Copper transporters had different patterns of occurrence than cuproproteins, suggesting that the pathways of copper utilization and copper detoxification are independent of each other. We present evidence that organisms living in oxygen-rich environments utilize copper, whereas the majority of anaerobic organisms do not. In addition, among copper users, cuproproteomes of aerobic organisms were larger than those of anaerobic organisms. Prokaryotic cuproproteomes were small and dominated by a single protein, cytochrome c oxidase. The data are consistent with the idea that proteins evolved to utilize copper following the oxygenation of the Earth.

Californium oxygen system for 1.50 < O/Cf < 1.72

International Nuclear Information System (INIS)

Turcotte, R.P.; Haire, R.G.

1975-01-01

The californium-oxygen system was studied as a function of temperature, oxygen pressure, and stoichiometry by manometric and x-ray diffraction methods. The results establish rhombohedral Cf 7 O 12 as the stable compound obtained by heating Cf 2 O 3 in air. The isobaric oxidation-reduction cycles Cf 2 O 3 → Cf 7 O 12 → Cf 2 O 3 , observed in constant rate of heating (cooling) experiments, occur with large hysteresis. A close parallel to other fluorite related lanthanide and actinide oxide systems is established. (auth)

Integrated design for space transportation system

CERN Document Server

Suresh, B N

2015-01-01

The book addresses the overall integrated design aspects of a space transportation system involving several disciplines like propulsion, vehicle structures, aerodynamics, flight mechanics, navigation, guidance and control systems, stage auxiliary systems, thermal systems etc. and discusses the system approach for design, trade off analysis, system life cycle considerations, important aspects in mission management, the risk assessment, etc. There are several books authored to describe the design aspects of various areas, viz., propulsion, aerodynamics, structures, control, etc., but there is no book which presents space transportation system (STS) design in an integrated manner. This book attempts to fill this gap by addressing systems approach for STS design, highlighting the integrated design aspects, interactions between various subsystems and interdependencies. The main focus is towards the complex integrated design to arrive at an optimum, robust and cost effective space transportation system. The orbit...

First-in-human pilot study of a spatial frequency domain oxygenation imaging system

Science.gov (United States)

Gioux, Sylvain; Mazhar, Amaan; Lee, Bernard T.; Lin, Samuel J.; Tobias, Adam M.; Cuccia, David J.; Stockdale, Alan; Oketokoun, Rafiou; Ashitate, Yoshitomo; Kelly, Edward; Weinmann, Maxwell; Durr, Nicholas J.; Moffitt, Lorissa A.; Durkin, Anthony J.; Tromberg, Bruce J.; Frangioni, John V.

2011-08-01

Oxygenation measurements are widely used in patient care. However, most clinically available instruments currently consist of contact probes that only provide global monitoring of the patient (e.g., pulse oximetry probes) or local monitoring of small areas (e.g., spectroscopy-based probes). Visualization of oxygenation over large areas of tissue, without a priori knowledge of the location of defects, has the potential to improve patient management in many surgical and critical care applications. In this study, we present a clinically compatible multispectral spatial frequency domain imaging (SFDI) system optimized for surgical oxygenation imaging. This system was used to image tissue oxygenation over a large area (16×12 cm) and was validated during preclinical studies by comparing results obtained with an FDA-approved clinical oxygenation probe. Skin flap, bowel, and liver vascular occlusion experiments were performed on Yorkshire pigs and demonstrated that over the course of the experiment, relative changes in oxygen saturation measured using SFDI had an accuracy within 10% of those made using the FDA-approved device. Finally, the new SFDI system was translated to the clinic in a first-in-human pilot study that imaged skin flap oxygenation during reconstructive breast surgery. Overall, this study lays the foundation for clinical translation of endogenous contrast imaging using SFDI.

Determination of the Minimal Fresh Gas Flow to Maintain a Therapeutic Inspired Oxygen Concentration in a Semi-Closed Anesthesia Circle System Using an Oxygen Concentrator as the Oxygen Source

National Research Council Canada - National Science Library

Grano, Joan

2001-01-01

The purpose of this study was to determine the rate of oxygen dilution, resulting from argon accumulation, using 3 low fresh gas flow rates using an oxygen concentrator in a semi-closed anesthesia circle system...

Design and control of the oxygen partial pressure of UO2 in TGA using the humidification system

International Nuclear Information System (INIS)

Lee, S.; Knight, T.W.; Roberts, E.

2015-01-01

Highlights: • We focus on measurement of oxygen partial pressure and change of O/M ratio under specific conditions produced by the humidification system. • This shows that the humidification system is stable, accurate, and reliable enough to be used for experiments of the oxygen partial pressure measurement for the oxide fuels. • The humidification system has benefits of easy control and flexibility for producing various oxygen partial pressures with fixed hydrogen gas flow rate. - Abstract: The oxygen to uranium (O/U) ratio of UO 2±x is determined by the oxygen content of the sample and is affected by oxygen partial pressure (pO 2 ) of the surrounding gas. Oxygen partial pressure is controllable by several methods. A common method to produce different oxygen partial pressures is the use of equilibria of different reaction gases. There are two common methods: H 2 O/H 2 reaction and CO 2 /CO reaction. In this work, H 2 O/H 2 reaction using a humidifier was employed and investigated to ensure that this humidification system for oxygen partial pressure is stable and accurate for use in Thermogravimetric Analyzer (TGA) experiments with UO 2 . This approach has the further advantage of flexibility to make a wide range of oxygen partial pressure with fixed hydrogen gas flow rate only by varying temperature of water in the humidifier. The whole system for experiments was constructed and includes the humidification system, TGA, oxygen analyzer, and gas flow controller. Uranium dioxide (UO 2 ) samples were used for experiments and oxygen partial pressure was measured at the equilibrium state of stoichiometric UO 2.0 . Oxygen partial pressures produced by humidification (wet gas) system were compared to the approach using mixed dry gases (without humidification system) to demonstrate that the humidification system provides for more stable and accurate oxygen partial pressure control. This work provides the design, method, and analysis of a humidification system for

Performances of the HL (Hyperloop) transport system

NARCIS (Netherlands)

van Goeverden, C.D.; Milakis, D.; Janic, M.; Konings, J.W.; Cools, M.; Limbourg, S.

2017-01-01

This paper deals with an analysis of performances of the HL (Hyperloop) transport system considered as an advanced transport alternative to the existing APT (Air Passenger Transport) and HSR (High Speed Rail) systems. The considered performances are operational, financial, social and environmental.

A multidimensonal Examination of Prefomences of the Future advanced Transport Systems: The ETT (Evacuated Tube Transport) TRM (Transrapid MAGLEV) System

NARCIS (Netherlands)

Janic, M.

2016-01-01

Multidimensional examination of performances of the future advanced ETT Evacuated Tube Transport) system operated by TRM (TransRapidMaglev); assessment of the ETT TRM system contribution to sustainability of the future transport sector through its completion with APT (Air Passenger Transport) system

Transport system

NARCIS (Netherlands)

Drenth, K.F.

1999-01-01

The transport system comprises at least one road surface (2) and at least one vehicle (4) on wheels (6). The road surface (2) has a substantially bowl-shaped cross section and the vehicle (4) is designed so that the wheels (6) run directly on the road surface (2) while the road surface (2) acts as a

Uso de sal durante o transporte de juvenis (1kg de pirarucu (Arapaima gigas Use of salt during the transportation of pirarucu juveniles (1kg (Arapaima gigas

Directory of Open Access Journals (Sweden)

Franmir Rodrigues Brandão

2008-12-01

Full Text Available O pirarucu é um peixe nativo da bacia Amazônica cuja criaçãovem sendo estudada em algumas partes do Brasil. O objetivo desse trabalho foi testar o sal de cozinha como mitigador de estresse durante o transporte de juvenis de pirarucu (1 kg. Para isso, os peixes foram transportados em dois diferentes sistemas: caixas sem adição de oxigênio (transporte aberto e sacos plásticos com injeção de oxigênio e lacrado (transporte fechado. Nos dois sistemas os peixes foram transportados em três diferentes tratamentos: controle e duas concentrações de sal na água (3 e 6 g.L-1. Após o transporte os peixes foram colocados em viveiros para avaliação da recuperação. Foram analisados parâmetros do metabolismo energético (cortisol, glicose e lactato e de hematologia (hematócrito. O sal de cozinha não foi eficiente em mitigar as respostas de estresse no transporte em nenhum dos dois sistemas de transporte estudados.Pirarucu is a native fish of the Amazon basin, widely used in culture systems in some parts of Brazil. The objective of this work was to test table salt as a stress mitigator during transportation of pirarucu juveniles (1kg. Fish were transported by two different systems: boxes without addition of oxygen (open system and closed oxygen filled plastic bags (closed system. To both systems fish were transported at three different treatments: control and two table salt concentration (3 and 6 gL-1. After transportation, fish were stocked in ponds to monitor recovery. Metabolic (cortisol, glucose and lactate and hematological (hematocrit parameters were analyzed. The table salt was not efficient in mitigating stress response during the both tested transport system.

Magnetic levitation -The future transport system

International Nuclear Information System (INIS)

Rairan, Danilo

2000-01-01

The paper made a recount of the main advantages and disadvantages of the traditional systems of transport with base in electric power and it shows as the systems that use the magnetic levitation they are the future of the transport. Additionally it presents the physical principle of operation of the two main systems developed at the present time

Hemodynamic and oxygen transport patterns for outcome prediction, therapeutic goals, and clinical algorithms to improve outcome. Feasibility of artificial intelligence to customize algorithms.

Science.gov (United States)

Shoemaker, W C; Patil, R; Appel, P L; Kram, H B

1992-11-01

A generalized decision tree or clinical algorithm for treatment of high-risk elective surgical patients was developed from a physiologic model based on empirical data. First, a large data bank was used to do the following: (1) describe temporal hemodynamic and oxygen transport patterns that interrelate cardiac, pulmonary, and tissue perfusion functions in survivors and nonsurvivors; (2) define optimal therapeutic goals based on the supranormal oxygen transport values of high-risk postoperative survivors; (3) compare the relative effectiveness of alternative therapies in a wide variety of clinical and physiologic conditions; and (4) to develop criteria for titration of therapy to the endpoints of the supranormal optimal goals using cardiac index (CI), oxygen delivery (DO2), and oxygen consumption (VO2) as proxy outcome measures. Second, a general purpose algorithm was generated from these data and tested in preoperatively randomized clinical trials of high-risk surgical patients. Improved outcome was demonstrated with this generalized algorithm. The concept that the supranormal values represent compensations that have survival value has been corroborated by several other groups. We now propose a unique approach to refine the generalized algorithm to develop customized algorithms and individualized decision analysis for each patient's unique problems. The present article describes a preliminary evaluation of the feasibility of artificial intelligence techniques to accomplish individualized algorithms that may further improve patient care and outcome.

Ultramicroelectrode studies of oxygen reduction in polyelectrolyte membranes

Energy Technology Data Exchange (ETDEWEB)

Holdcroft, S.; Abdou, M.S.; Beattie, P.; Basura, V. [Simon Fraser Univ., Burnaby, BC (Canada). Dept. of Chemistry

1997-12-31

A study on the oxygen reduction reaction in a solid state electrochemical cell was presented. The oxygen reduction reaction is a rate limiting reaction in the operation of solid polymer electrolyte fuel cells which use H{sub 2} and O{sub 2}. Interest in the oxygen reduction reaction of platinum electrodes in contact with Nafion electrolytes stems from its role in fuel cell technology. The kinetics of the oxygen reduction reaction in different polyelectrolyte membranes, such as Nafion and non-Nafion membranes, were compared. The electrode kinetics and mass transport parameters of the oxygen reduction reaction in polyelectrolyte membranes were measured by ultramicroelectrode techniques. The major difference found between these two classes of membrane was the percentage of water, which is suggestive of superior electrochemical mass transport properties of the non-Nafion membranes. 2 refs. 1 fig.

Mitochondrial Respiration and Oxygen Tension.

Science.gov (United States)

Shaw, Daniel S; Meitha, Karlia; Considine, Michael J; Foyer, Christine H

2017-01-01

Measurements of respiration and oxygen tension in plant organs allow a precise understanding of mitochondrial capacity and function within the context of cellular oxygen metabolism. Here we describe methods that can be routinely used for the isolation of intact mitochondria, and the determination of respiratory electron transport, together with techniques for in vivo determination of oxygen tension and measurement of respiration by both CO 2 production and O 2 consumption that enables calculation of the respiratory quotient [CO 2 ]/[O 2 ].

Ambulatory oxygen: why do COPD patients not use their portable systems as prescribed? A qualitative study

Directory of Open Access Journals (Sweden)

Fenwick Angela

2011-02-01

Full Text Available Abstract Background Patients with COPD on long term oxygen therapy frequently do not adhere to their prescription, and they frequently do not use their ambulatory oxygen systems as intended. Reasons for this lack of adherence are not known. The aim of this study was to obtain in-depth information about perceptions and use of prescribed ambulatory oxygen systems from patients with COPD to inform ambulatory oxygen design, prescription and management. Methods A qualitative design was used, involving semi-structured face-to-face interviews informed by a grounded theory approach. Twenty-seven UK community-dwelling COPD patients using NHS prescribed ambulatory systems were recruited. Ambulatory oxygen systems comprised cylinders weighing 3.4 kg, a shoulder bag and nasal cannulae. Results Participants reported that they: received no instruction on how to use ambulatory oxygen; were uncertain of the benefits; were afraid the system would run out while they were using it (due to lack of confidence in the cylinder gauge; were embarrassed at being seen with the system in public; and were unable to carry the system because of the cylinder weight. The essential role of carers was also highlighted, as participants with no immediate carers did not use ambulatory oxygen outside the house. Conclusions These participants highlighted previously unreported problems that prevented them from using ambulatory oxygen as prescribed. Our novel findings point to: concerns with the lack of specific information provision; the perceived unreliability of the oxygen system; important carer issues surrounding managing and using ambulatory oxygen equipment. All of these issues, as well as previously reported problems with system weight and patient embarrassment, should be addressed to improve adherence to ambulatory oxygen prescription and enhance the physical and social benefits of maintaining mobility in this patient group. Increased user involvement in both system development

A system for oxygen-15 labeled blood for medical applications

International Nuclear Information System (INIS)

Subramanyam, R.; Bucelewicz, W.M.; Hoop, B. Jr.; Jones, S.C.

1977-01-01

Oxygen-15 labeled compounds in blood have been used successfully for cerebral circulation and cerebral oxygen metabolism measurements. The present paper describes a system for the rapid sequential production of 15 O-HgB, C 15 O-Hgb and H 2 15 O in blood under sterile and pyrogen-free conditions. A tonometer has been adopted for labeling blood without hemolysis and foam production. (author)

The beneficial role of rubble mound coastal structures on seawater oxygenation

Directory of Open Access Journals (Sweden)

E. I. Daniil

2000-10-01

Full Text Available The beneficial role of rubble mound coastal structures on oxygenation under the effect of waves is discussed, based on analytical considerations and experimental data from laboratory experiments with permeable and impermeable structures. Significant oxygenation of the wave-protected area was observed as a result of horizontal transport through the permeable structure. A two-cell model describing the transport of dissolved oxygen (DO near a rubble mound breakwater structure was developed and used for the determination of the oxygen transfer coefficients from the experimental data. Oxygen transfer through the air–water interface is considered a source term in the transport equation and the oxygen flux through the structure is taken into account. The mass transport equations for both sides of the structure are solved analytically in terms of time evolution of DO concentration. The behaviour of the solution is illustrated for three different characteristic cases of initial conditions. The oxygen transfer through the air-water interface in the wave-influenced area increases the DO content in the area; the resulting oxygen flux through the structure is discussed. The analytical results depend on the initial conditions, the oxygen transfer coefficient and the exchange flow rate through the structure. Experiments with impermeable structures show that air water oxygen transfer in the harbour area is negligible in the absence of waves. In addition the ratio of the horizontal DO flux to the vertical flux into the seaward side tends towards a constant value, independent of the initial conditions.Key words: Oceanography: physical (air-sea interactions; surface waves and tides

Oxygen diffusion in nanocrystalline yttria-stabilized zirconia: the effect of grain boundaries.

Science.gov (United States)

De Souza, Roger A; Pietrowski, Martha J; Anselmi-Tamburini, Umberto; Kim, Sangtae; Munir, Zuhair A; Martin, Manfred

2008-04-21

The transport of oxygen in dense samples of yttria-stabilized zirconia (YSZ), of average grain size d approximately 50 nm, has been studied by means of 18O/16O exchange annealing and secondary ion mass spectrometry (SIMS). Oxygen diffusion coefficients (D*) and oxygen surface exchange coefficients (k*) were measured for temperatures 673oxygen partial pressure of 900 mbar. No evidence is found for fast diffusion along grain boundaries. Rather, the analysis indicates that grain boundaries hinder oxygen transport.

Oxygen transport and degradation properties of high-temperature membranes for CO{sub 2}-free power plants; Sauerstofftransport und Degradationsverhalten von Hochtemperaturmembranen fuer CO{sub 2}-freie Kraftwerke

Energy Technology Data Exchange (ETDEWEB)

Schlehuber, Dominic

2010-07-01

This thesis deals with membranes for oxygen separation from air for high temperature application in fossil power plants within the scope of the oxyfuel-process. Different perovskite membrane materials (ABO3-ae) were investigated concerning the oxygen transport and their chemical stability under operation condition. The association between oxygen transport properties and both the thermodynamic boundary conditions as well as the material properties (membrane thickness and surface properties) was studied. One possibility to achieve higher oxygen fluxes through the membrane is to reduce the thickness. In this case the influence of surface processes on the overall permeation becomes noteworthy. The effect of different membrane surface modifications on the permeation rate was investigated. For example it could be confirmed, that a porous layer on the membrane surface significantly increases the permeation flux due to the compensation of surface exchange limitations. Beyond that, degradation processes during the operation under power plant condition were investigated. Special attention was attached to the influence of degradation on the permeation flux during long term operation. Thereby kinetic demixing of the membrane material was observed. (orig.)

LCLS-II CRYOMODULE TRANSPORT SYSTEM TESTING

Energy Technology Data Exchange (ETDEWEB)

Huque, Naeem [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Daly, Edward F. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); McGee, Michael W. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2018-04-01

The Cryomodules (CM) for the Linear Coherent Light Source II (LCLS-II) will be shipped to SLAC (Menlo Park, California) from JLab (Newport News, Virginia) and FNAL (Batavia, Illinois). A transportation system has been designed and built to safely transport the CMs over the road. It uses an array of helical isolator springs to attenuate shocks on the CM to below 1.5g in all directions. The system rides on trailers equipped with Air-Ride suspension, which attenuates vibration loads. The prototype LCLS-II CM (pCM) was driven 750 miles to test the transport system; shock loggers recorded the shock attenuation on the pCM and vacuum gauges were used to detect any compromises in beamline vacuum. Alignment measurements were taken before and after the trip to check whether cavity positions had shifted beyond the ± 0.2mm spec. Passband frequencies and cavity gradients were measured at 2K at the Cryomodule Test Facility (CMTF) at JLab to identify any degradation of CM performance after transportation. The transport system was found to have safely carried the CM and is cleared to begin shipments from JLab and FNAL to SLAC.

OXYGEN TRANSPORT CERAMIC MEMBRANES

International Nuclear Information System (INIS)

Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

2002-01-01

Conversion of natural gas to liquid fuels and chemicals is a major goal for the Nation as it enters the 21st Century. Technically robust and economically viable processes are needed to capture the value of the vast reserves of natural gas on Alaska's North Slope, and wean the Nation from dependence on foreign petroleum sources. Technologies that are emerging to fulfill this need are all based syngas as an intermediate. Syngas (a mixture of hydrogen and carbon monoxide) is a fundamental building block from which chemicals and fuels can be derived. Lower cost syngas translates directly into more cost-competitive fuels and chemicals. The currently practiced commercial technology for making syngas is either steam methane reforming (SMR) or a two-step process involving cryogenic oxygen separation followed by natural gas partial oxidation (POX). These high-energy, capital-intensive processes do not always produce syngas at a cost that makes its derivatives competitive with current petroleum-based fuels and chemicals

Graphite and PMMA as pore formers for thermoplastic extrusion of porous 3Y-TZP oxygen transport membrane supports

DEFF Research Database (Denmark)

Bjørnetun Haugen, Astri; Gurauskis, Jonas; Kaiser, Andreas

2016-01-01

A gas permeable porous support is a crucial part of an asymmetric oxygen transport membrane (OTM). Here, we develop feedstocks for thermoplastic extrusion of tubular, porous 3Y-TZP (partially stabilized zirconia polycrystals, (Y2O3)0.03(ZrO2)0.97)) ceramics, using graphite and/or polymethyl....... This demonstrates the suitability of thermoplastic extrusion for fabrication of porous 3Y-TZP OTM supports, or for other technologies requiring porous ceramics....

Not planning a sustainable transport system

International Nuclear Information System (INIS)

Finnveden, Göran; Åkerman, Jonas

2014-01-01

The overall objective of the Swedish transport policy is to ensure the economically efficient and sustainable provision of transport services for people and business throughout the country. More specifically, the transport sector shall, among other things, contribute to the achievement of environmental quality objectives in which the development of the transport system plays an important role in the achievement of the objectives. The aim of this study is to analyse if current transport planning supports this policy. This is done by analysing two recent cases: the National Infrastructure Plan 2010–2021, and the planning of Bypass Stockholm, a major road investment. Our results show that the plans are in conflict with several of the environmental quality objectives. Another interesting aspect of the planning processes is that the long-term climate goals are not included in the planning processes, neither as a clear goal nor as factor that will influence future transport systems. In this way, the long-term sustainability aspects are not present in the planning. We conclude that the two cases do not contribute to a sustainable transport system. Thus, several changes must be made in the processes, including putting up clear targets for emissions. Also, the methodology for the environmental assessments needs to be further developed and discussed. - Highlights: • Two cases are studied to analyse if current planning supports a sustainable transport system. • Results show that the plans are in conflict with several of the environmental quality objectives. • Long-term climate goals are not included in the planning processes. • Current practices do not contribute to a sustainable planning processes. • Methodology and process for environmental assessments must be further developed and discussed

Not planning a sustainable transport system

Energy Technology Data Exchange (ETDEWEB)

Finnveden, Göran, E-mail: goran.finnveden@abe.kth.se; Åkerman, Jonas

2014-04-01

The overall objective of the Swedish transport policy is to ensure the economically efficient and sustainable provision of transport services for people and business throughout the country. More specifically, the transport sector shall, among other things, contribute to the achievement of environmental quality objectives in which the development of the transport system plays an important role in the achievement of the objectives. The aim of this study is to analyse if current transport planning supports this policy. This is done by analysing two recent cases: the National Infrastructure Plan 2010–2021, and the planning of Bypass Stockholm, a major road investment. Our results show that the plans are in conflict with several of the environmental quality objectives. Another interesting aspect of the planning processes is that the long-term climate goals are not included in the planning processes, neither as a clear goal nor as factor that will influence future transport systems. In this way, the long-term sustainability aspects are not present in the planning. We conclude that the two cases do not contribute to a sustainable transport system. Thus, several changes must be made in the processes, including putting up clear targets for emissions. Also, the methodology for the environmental assessments needs to be further developed and discussed. - Highlights: • Two cases are studied to analyse if current planning supports a sustainable transport system. • Results show that the plans are in conflict with several of the environmental quality objectives. • Long-term climate goals are not included in the planning processes. • Current practices do not contribute to a sustainable planning processes. • Methodology and process for environmental assessments must be further developed and discussed.

Material Usage in High Pressure Oxygen Systems for the International Space Station

Science.gov (United States)

Kravchenko, Michael; Sievers, D. Elliott

2014-01-01

The Nitrogen/Oxygen Recharge System (NORS) for the International Space Station (ISS) Program was required as part of the Space Shuttle retirement efforts to sustain the ISS life support systems. The system is designed around a 7000 psia Oxygen or Nitrogen Recharge Tank Assembly which is able to be utilized both internally and externally to the ISS. Material selection and usage were critical to ensure oxygen compatibility for the design, while taking into consideration toxicity, weldability, brazability and general fabrication and assembly techniques. The system uses unique hardware items such a composite overwrap pressure vessel (COPV), high pressure mechanical gauges, compact regulators and valves, quick disconnects, metal tubing and flexhoses. Numerous challenges and anomalies were encountered due to the exotic nature of this project which will be discussed in detail. The knowledge gained from these anomalies and failure resolutions can be applied to more than space applications, but can also be applicable to industry pressurized systems.

High-Energy-Density Metal-Oxygen Batteries: Lithium-Oxygen Batteries vs Sodium-Oxygen Batteries.

Science.gov (United States)

Song, Kyeongse; Agyeman, Daniel Adjei; Park, Mihui; Yang, Junghoon; Kang, Yong-Mook

2017-12-01

The development of next-generation energy-storage devices with high power, high energy density, and safety is critical for the success of large-scale energy-storage systems (ESSs), such as electric vehicles. Rechargeable sodium-oxygen (Na-O 2 ) batteries offer a new and promising opportunity for low-cost, high-energy-density, and relatively efficient electrochemical systems. Although the specific energy density of the Na-O 2 battery is lower than that of the lithium-oxygen (Li-O 2 ) battery, the abundance and low cost of sodium resources offer major advantages for its practical application in the near future. However, little has so far been reported regarding the cell chemistry, to explain the rate-limiting parameters and the corresponding low round-trip efficiency and cycle degradation. Consequently, an elucidation of the reaction mechanism is needed for both lithium-oxygen and sodium-oxygen cells. An in-depth understanding of the differences and similarities between Li-O 2 and Na-O 2 battery systems, in terms of thermodynamics and a structural viewpoint, will be meaningful to promote the development of advanced metal-oxygen batteries. State-of-the-art battery design principles for high-energy-density lithium-oxygen and sodium-oxygen batteries are thus reviewed in depth here. Major drawbacks, reaction mechanisms, and recent strategies to improve performance are also summarized. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Advanced Transport Operating Systems Program

Science.gov (United States)

White, John J.

1990-01-01

NASA-Langley's Advanced Transport Operating Systems Program employs a heavily instrumented, B 737-100 as its Transport Systems Research Vehicle (TRSV). The TRSV has been used during the demonstration trials of the Time Reference Scanning Beam Microwave Landing System (TRSB MLS), the '4D flight-management' concept, ATC data links, and airborne windshear sensors. The credibility obtainable from successful flight test experiments is often a critical factor in the granting of substantial commitments for commercial implementation by the FAA and industry. In the case of the TRSB MLS, flight test demonstrations were decisive to its selection as the standard landing system by the ICAO.

Isotope anomalies in oxygen isotope exchange equilibrium systems

International Nuclear Information System (INIS)

Kotaka, M.

1997-01-01

The purpose of the present work is to elucidate the isotope anomalies in oxygen isotope exchange equilibrium systems, according to the calculations of the equilibrium constants for oxygen isotopic exchange reactions, and the calculations of the oxygen isotope separation factors between two phases. The equilibrium constants (K65, K67, K68 and K69) of 16 O- 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O exchange reactions between diatomic oxides were calculated in a wide temperature range on the basis of quantum statistical mechanics. Many equilibrium constants showed the anomalous mass effects, and then had the crossover temperatures and the mass independent fractionation (MIF) temperatures which held K67 = K65, K67 = K68, or K67 = K69, etc. For example, the equilibrium constants for the reactions between OH and the other diatomic oxides (MO) showed the anomalous mass effects, when M was Li, Na, Mg, K, Fe, Al, Ge, Zr, Pt, etc. The 16 O 15 O, 16 O 17 O, 16 O- 18 O, and 16 O- 19 O oxygen isotope separation factors (S65, S67, S68 and S69) between two phases were calculated, when OH and CO were in the first phase, and SiO was in the second phase. Although the oxygen isotopic exchange equilibria in the two phases had no MIF and crossover temperatures, the separation factors showed the anomalous mass effects and had the temperatures. According to what is called the normal mass effects for the equilibrium constant of isotopic exchange reaction, the value of InK68/InK67 is 1.885. Therefore, the value of InS68/InS67 should be 1.885 too. The value calculated, however, widely changed. It can be concluded from the results obtained in the present work that some oxygen isotopic exchange equilibria cause the anomalous mass effects, the anomalous oxygen isotope separation factors, and then isotope anomalies

Oxygen diffusion in bilayer polymer films

DEFF Research Database (Denmark)

Poulsen, Lars; Zebger, Ingo; Tofte, Jannik Pentti

2004-01-01

Experiments to quantify oxygen diffusion have been performed on polymer samples in which a film of poly(ethylene-co-norbornene) was cast onto a film of polystyrene which, in turn, was cast onto an oxygen-impermeable substrate. In the technique employed, the time evolution of oxygen transport...... through the film of poly(ethylene-co-norbornene) and into the polystyrene film was monitored using the phosphorescence of singlet oxygen as a spectroscopic probe. To analyze the data, it was necessary to solve Fick's second law of diffusion for both polymer films. Tractable analytical and numerical...

Surveillance systems for intermodal transportation

Science.gov (United States)

Jakovlev, Sergej; Voznak, Miroslav; Andziulis, Arunas

2015-05-01

Intermodal container monitoring is considered a major security issue in many major logistic companies and countries worldwide. Current representation of the problem, we face today, originated in 2002, right after the 9/11 attacks. Then, a new worldwide Container Security Initiative (CSI, 2002) was considered that shaped the perception of the transportation operations. Now more than 80 larger ports all over the world contribute to its further development and integration into everyday transportation operations and improve the regulations for the developing regions. Although, these new improvements allow us to feel safer and secure, constant management of transportation operations has become a very difficult problem for conventional data analysis methods and information systems. The paper deals with a proposal of a whole new concept for the improvement of the Containers Security Initiative (CSI) by virtually connecting safety, security processes and systems. A conceptual middleware approach with deployable intelligent agent modules is proposed to be used with possible scenarios and a testbed is used to test the solution. Middleware examples are visually programmed using National Instruments LabView software packages and Wireless sensor network hardware modules. An experimental software is used to evaluate he solution. This research is a contribution to the intermodal transportation and is intended to be used as a means or the development of intelligent transport systems.

The Exchange Value Embedded in a Transport System

International Nuclear Information System (INIS)

Xia Qinglan; Xu Shaofeng

2010-01-01

This paper shows that a well designed transport system has an embedded exchange value by serving as a market for potential exchange between consumers. Under suitable conditions, one can improve the welfare of consumers in the system simply by allowing some exchange of goods between consumers during transportation without incurring additional transportation cost. We propose an explicit valuation formula to measure this exchange value for a given compatible transport system. This value is always nonnegative and bounded from above. Criteria based on transport structures, preferences and prices are provided to determine the existence of a positive exchange value. Finally, we study a new optimal transport problem with an objective taking into account of both transportation cost and exchange value.

Power Systems Development Facility Gasification Test Run TC09

Energy Technology Data Exchange (ETDEWEB)

Southern Company Services

2002-09-30

This report discusses Test Campaign TC09 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed gasifier designed to operate as either a combustor or a gasifier in air- or oxygen-blown mode of operation using a particulate control device (PCD). The Transport Gasifier was operated as a pressurized gasifier during TC09 in air- and oxygen-blown modes. Test Run TC09 was started on September 3, 2002, and completed on September 26, 2002. Both gasifier and PCD operations were stable during the test run, with a stable baseline pressure drop. The oxygen feed supply system worked well and the transition from air to oxygen was smooth. The gasifier temperature varied between 1,725 and 1,825 F at pressures from 125 to 270 psig. The gasifier operates at lower pressure during oxygen-blown mode due to the supply pressure of the oxygen system. In TC09, 414 hours of solid circulation and over 300 hours of coal feed were attained with almost 80 hours of pure oxygen feed.

78 FR 1765 - Requirements for Chemical Oxygen Generators Installed on Transport Category Airplanes

Science.gov (United States)

2013-01-09

... appropriate; and (6) Consider the pros and cons of different implementation options and recommend a schedule(s... recommendations. D. New Technology Irrespective of the method chosen to provide supplemental oxygen, there may be... developments in system technology have made a more direct approach feasible for meeting the physiological...

Organelle-localized potassium transport systems in plants.

Science.gov (United States)

Hamamoto, Shin; Uozumi, Nobuyuki

2014-05-15

Some intracellular organelles found in eukaryotes such as plants have arisen through the endocytotic engulfment of prokaryotic cells. This accounts for the presence of plant membrane intrinsic proteins that have homologs in prokaryotic cells. Other organelles, such as those of the endomembrane system, are thought to have evolved through infolding of the plasma membrane. Acquisition of intracellular components (organelles) in the cells supplied additional functions for survival in various natural environments. The organelles are surrounded by biological membranes, which contain membrane-embedded K(+) transport systems allowing K(+) to move across the membrane. K(+) transport systems in plant organelles act coordinately with the plasma membrane intrinsic K(+) transport systems to maintain cytosolic K(+) concentrations. Since it is sometimes difficult to perform direct studies of organellar membrane proteins in plant cells, heterologous expression in yeast and Escherichia coli has been used to elucidate the function of plant vacuole K(+) channels and other membrane transporters. The vacuole is the largest organelle in plant cells; it has an important task in the K(+) homeostasis of the cytoplasm. The initial electrophysiological measurements of K(+) transport have categorized three classes of plant vacuolar cation channels, and since then molecular cloning approaches have led to the isolation of genes for a number of K(+) transport systems. Plants contain chloroplasts, derived from photoautotrophic cyanobacteria. A novel K(+) transport system has been isolated from cyanobacteria, which may add to our understanding of K(+) flux across the thylakoid membrane and the inner membrane of the chloroplast. This chapter will provide an overview of recent findings regarding plant organellar K(+) transport proteins. Copyright © 2014 Elsevier GmbH. All rights reserved.

Development of thin film oxygen transport membranes on metallic supports

Energy Technology Data Exchange (ETDEWEB)

Xing, Ye

2012-04-25

interlayer, though it comprised some cracks. The second interlayer had a crack-free and porous structure. The top membrane layer was deposited by physical vapor deposition (magnetron sputtering) with a thickness of 3.8 {mu}m improving the gastightness considerably but showing still reasonable air-leakage. Summarizing, the successful development of a metal-perovskite-composite could be shown, which acts as a basis for a further development of a gas-tight metal supported oxygen transport asymmetric membrane structure. (orig.)

High energy lithium-oxygen batteries - Transport barriers and thermodynamics

KAUST Repository

Das, Shyamal K.

2012-01-01

We show that it is possible to achieve higher energy density lithium-oxygen batteries by simultaneously lowering the discharge overpotential and increasing the discharge capacity via thermodynamic variables alone. By assessing the relative effects of temperature and pressure on the cell discharge profiles, we characterize and diagnose the critical roles played by multiple dynamic processes that have hindered implementation of the lithium-oxygen battery. © 2012 The Royal Society of Chemistry.

Urban Transportation Planning Short Course: Evaluation of Alternative Transportation Systems.

Science.gov (United States)

Federal Highway Administration (DOT), Washington, DC.

This urban transportation pamphlet delves into the roles of policy groups and technical staffs in evaluating alternative transportation plans, evaluation criteria, systems to evaluate, and evaluation procedures. The introduction admits the importance of subjective, but informed, judgment as an effective tool in weighing alternative transportation…

PHOTOINDUCED TRANSFER OF OXYGEN FROM WATER: AN ARTIFICAL PHOTOSYNTHETIC SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Willner, Itamar; Otvos, John W.; Ford, William E.; Mettee, Howard; Calvin, Melvin

1979-11-01

The photoinduced splitting of water into hydrogen and oxygen has evoked great interest in recent years as a means for energy storag eand fuel production. Photoinduced reduction of water to hydrogen, using visible light, has been described using heterogeneous or homogeneous catalysts. However, the complementary part involving the oxidation of water to oxygen is required in order to create a cyclic artificial 'photosynthetic' fuel system. The major difficulty assocaited with the photooxidation of water involves the requirement for a four electron transfer to produce oxygen. A stepwise one-electron oxidation of water is unfavorable due to the implied formation of active hydroxyl radicals. Very recently, it has been reported that RuO{sub 2} can serve as a heterogeneous charge storage catalyst for oxygen production. On the basis of the limited knowledge about natural photosynthesis, in which manganese ions play an important role in oxygen evolution, synthetic manganese complexes, and in particular dimeric complexes, have been proposed as potential catalysts for oxygen production. So far, efforts directed toward this goal have been unsuccessful. Consequently, using a manganese complex, they attempted to perform a photoinduced oxidation of water whereby the active oxygen is transferred to a trapping substrate. In such a way, the requirement for a dimerization process to evolve molecular oxygen is avoided. They wish to report a photoinduced redox cycle sensitized by a manganese porphyrin, 5-(4{prime}-hexadecylpyridium)-10, 15, 20-tri (4{prime}-pyridyl)-porphinatomanganese(III) (abbreciated to Pn-Mn{sup III}) in which the resultant reaction is the oxidation of water and trapping of the single oxygen atom by a substrate (triphenylphosphine).

Evaluation of a Gentex (registered trademark) ORO-NASAL Oxygen Mask for Integration with the Aqualung (registered trademark) Personal Helicopter Oxygen Delivery System (PHODS)

National Research Council Canada - National Science Library

Roller, Richard A; Curry, Ian P

2008-01-01

.... The United States Army Aeromedical Research Laboratory (USAARL) was tasked by the Product Manager Air Warrior to evaluate an oxygen mask for use with the Personal Helicopter Oxygen Delivery System (PHODS...

Comparison of airline passenger oxygen systems.

Science.gov (United States)

Byrne, N J

1995-08-01

The principal sources of oxygen for inflight passenger use, scheduled and unscheduled, are examined. Present practices of assessment of the passenger's "fitness to fly" are described. Three partner airlines, British Airways, U.S. Air, and Qantas, catering for more than 8000 oxygen requests annually, are compared. Analysis of customer use suggests that medical oxygen requests are frequently not clinically justified. The growth in demand, for both scheduled and unscheduled use of an expensive resource, supports the need for a "recommended best practice" among carriers. Passengers with respiratory disorders who will most benefit from inflight oxygen are vulnerable either to hypoxia or asthma.

Sustainable Transport in Romania vs. European Union. Analysis of Road Transport System from the Sustainable Transport Perspective

Directory of Open Access Journals (Sweden)

Clitan Andrei - Florin

2014-12-01

Full Text Available Sustainability is a term used more often lately, based on three factors: social, economic, and environmental. Sustainable transport systems increase social cohesion, reduce environmental problems and help create a more efficient economy. Sustainable transport consists in a complex system that is designed to ensure mobility needs of present generations without damaging the environment and health factors. By improving energy and material consumption, it must be capable to satisfy in optimum conditions the need for mobility for future generations. The current transportation system has not a character of sustainability.

The WIPP transportation system -- ''Safer than any other''

International Nuclear Information System (INIS)

Ward, T.R.; Spooner, R.

1991-01-01

The Department of Energy (DOE) has developed an integrated transportation system to transport transuranic (TRU) waste from ten widely dispersed generator sites to the Waste Isolation Pilot Plant (WIPP). The system consists of a Type B container, a specially designed trailer, a lightweight tractor, the DOE TRANSCOM satellite-based vehicle tracking system, and uniquely qualified and highly trained drivers. The DOE has demonstrated that this system is ready to transport the TRU waste to the WIPP site efficiently and safely. Since the system was put in place in November 1988, it has been repeatedly upgraded and enhanced to incorporate additional safety measures. In June of 1989, the National Academy of Sciences (NAS) reviewed the transportation system and concluded that ''the system proposed for transportation of TRU waste to WIPP is safer than that employed for any other hazardous material in the United States today and will reduce risk to very low levels'' (emphasis added). The NAS conclusion was made before the DOE implemented the Enhanced Driver Training Course for carrier drivers. The challenge facing the DOE was to examine the transportation system objectively and determine what additional improvements could be made to further enhance safety

Systemic Analysis Approaches for Air Transportation

Science.gov (United States)

Conway, Sheila

2005-01-01

Air transportation system designers have had only limited success using traditional operations research and parametric modeling approaches in their analyses of innovations. They need a systemic methodology for modeling of safety-critical infrastructure that is comprehensive, objective, and sufficiently concrete, yet simple enough to be used with reasonable investment. The methodology must also be amenable to quantitative analysis so issues of system safety and stability can be rigorously addressed. However, air transportation has proven itself an extensive, complex system whose behavior is difficult to describe, no less predict. There is a wide range of system analysis techniques available, but some are more appropriate for certain applications than others. Specifically in the area of complex system analysis, the literature suggests that both agent-based models and network analysis techniques may be useful. This paper discusses the theoretical basis for each approach in these applications, and explores their historic and potential further use for air transportation analysis.

Diffusion of oxygen through cork stopper: is it a Knudsen or a Fickian mechanism?

Science.gov (United States)

Lagorce-Tachon, Aurélie; Karbowiak, Thomas; Simon, Jean-Marc; Gougeon, Régis; Bellat, Jean-Pierre

2014-09-17

The aim of this work is to identify which law governs oxygen transfer through cork: Knudsen or Fickian mechanism. This is important to better understand wine oxidation during post-bottling aging. Oxygen transfer through cork wafers is measured at 298 K using a manometric permeation technique. Depending on the mechanism, we can extract the transport coefficients. Increasing the initial pressure of oxygen from 50 to 800 hPa leads to a change in the values of the transport coefficients. This implies that oxygen transport through cork does not obey the Knudsen law. From these results, we conclude that the limiting step of oxygen transport through cork occurs in the cell wall following Fickian law. From the diffusion dependence's coefficients with pressure, we also extract by applying transition state theory an apparent activation volume of 45 ± 4 nm(3). This high value indicates that oxygen molecules also diffuse from one site to another by passing through a gas phase.

Advanced transport systems analysis, modeling, and evaluation of performances

CERN Document Server

Janić, Milan

2014-01-01

This book provides a systematic analysis, modeling and evaluation of the performance of advanced transport systems. It offers an innovative approach by presenting a multidimensional examination of the performance of advanced transport systems and transport modes, useful for both theoretical and practical purposes. Advanced transport systems for the twenty-first century are characterized by the superiority of one or several of their infrastructural, technical/technological, operational, economic, environmental, social, and policy performances as compared to their conventional counterparts. The advanced transport systems considered include: Bus Rapid Transit (BRT) and Personal Rapid Transit (PRT) systems in urban area(s), electric and fuel cell passenger cars, high speed tilting trains, High Speed Rail (HSR), Trans Rapid Maglev (TRM), Evacuated Tube Transport system (ETT), advanced commercial subsonic and Supersonic Transport Aircraft (STA), conventionally- and Liquid Hydrogen (LH2)-fuelled commercial air trans...

Electrical Power Systems for NASA's Space Transportation Program

Science.gov (United States)

Lollar, Louis F.; Maus, Louis C.

1998-01-01

Marshall Space Flight Center (MSFC) is the National Aeronautics and Space Administration's (NASA) lead center for space transportation systems development. These systems include earth to orbit launch vehicles, as well as vehicles for orbital transfer and deep space missions. The tasks for these systems include research, technology maturation, design, development, and integration of space transportation and propulsion systems. One of the key elements in any transportation system is the electrical power system (EPS). Every transportation system has to have some form of electrical power and the EPS for each of these systems tends to be as varied and unique as the missions they are supporting. The Preliminary Design Office (PD) at MSFC is tasked to perform feasibility analyses and preliminary design studies for new projects, particularly in the space transportation systems area. All major subsystems, including electrical power, are included in each of these studies. Three example systems being evaluated in PD at this time are the Liquid Fly Back Booster (LFBB) system, the Human Mission to Mars (HMM) study, and a tether based flight experiment called the Propulsive Small Expendable Deployer System (ProSEDS). These three systems are in various stages of definition in the study phase.

Estimated routine radiation doses to transportation workers in alternative spent-fuel transportation systems

International Nuclear Information System (INIS)

Schneider, K.J.; Smith, R.I.; Daling, P.M.; Ross, W.A.; McNair, G.W.

1988-01-01

The federal system for the management of spent fuel and high-level radioactive waste includes the acceptance by the US Department of Energy (DOE) of the spent fuel or waste loaded in casks at the reactor or other waste generators, its transportation to a repository, and its handling and final emplacement in the repository. The DOE plans to implement a transportation system that is safe, secure, efficient, and cost-effective and will meet applicable regulatory safety and security requirements. The DOE commissioned the Pacific Northwest Laboratory (PNL) to develop estimates of the routine radiation doses that would result from the operation of a system postulated using current designs and practices. From that evaluation, PNL identified activities/operations that result in the higher fraction of doses, proposed conceptual alternatives that would effectively reduce such exposures, and evaluated the cost-effectiveness of such alternatives. The study is one of a series used in making overall system design and operational decisions in the development of the DOE's spent-fuel/high-level waste transportation system. This paper contains the highlights from the PNL study of the estimated radiation doses to the transportation workers in a postulated reference transportation system and potential alternatives to that system

Improvement of urban passenger transport ticketing systems by deploying intelligent transport systems

Directory of Open Access Journals (Sweden)

G. Jakubauskas

2006-12-01

Full Text Available The main advantages and disadvantages of conventional and intelligent ticketing systems and possible positive outcomes when introducing intelligent transport solutions – namely smart cards or e‑ticketing instead of conventional ones (paper tickets and magnetic cards are analysed in the paper. Two ideas of creating an intelligent ticketing system in an urban public transport are scrutinized. The first is electronic ticket and related equipment, the second – e-ticket and functional areas of it. In the article analysis has also been made on practical outcomes related with introduction of smart cards and e-ticketing. Practical tests and trials as well as a subsequent implementation of electronic tickets have proved unchallenged advantages of contactless smart cards against the contact ones. Nevertheless, a new age of modern technologies calls even for more effective solutions – namely virtual-ticketing systems that might be achieved through introduction of mobile technologies. Therefore, the main focus in the paper is made on the analysis of e-ticket.

Common catabolic enzyme patterns in a microplankton community of the Humboldt Current System off northern and central-south Chile: Malate dehydrogenase activity as an index of water-column metabolism in an oxygen minimum zone

Science.gov (United States)

González, R. R.; Quiñones, R. A.

2009-07-01

An extensive subsurface oxygen minimum zone off northern and central-south Chile, associated with the Peru-Chile undercurrent, has important effects on the metabolism of the organisms inhabiting therein. Planktonic species deal with the hypoxic and anoxic environments by relying on biochemical as well as physiological processes related to their anaerobic metabolisms. Here we characterize, for the first time, the potential enzymatic activities involved in the aerobic and anaerobic energy production pathways of microplanktonic organisms (oxygen concentration and microplanktonic biomass in the oxygen minimum zone and adjacent areas of the Humboldt Current System water column. Our results demonstrate significant potential enzymatic activity of catabolic pathways in the oxygen minimum zone. Malate dehydrogenase had the highest oxidizing activity of nicotinamide adenine dinucleotide (reduced form) in the batch of catabolic enzymatic activities assayed, including potential pyruvate oxidoreductases activity, the electron transport system, and dissimilatory nitrate reductase. Malate dehydrogenase correlated significantly with almost all the enzymes analyzed within and above the oxygen minimum zone, and also with the oxygen concentration and microplankton biomass in the water column of the Humboldt Current System, especially in the oxygen minimum zone off Iquique. These results suggest a possible specific pattern for the catabolic activity of the microplanktonic realm associated with the oxygen minimum zone spread along the Humboldt Current System off Chile. We hypothesize that malate dehydrogenase activity could be an appropriate indicator of microplankton catabolism in the oxygen minimum zone and adjacent areas.

Lightweight Monorail Transport System

Science.gov (United States)

Weir, Harold F.; Wood, Kenneth E.; Strecker, Myron T.

1987-01-01

Report proposes monorail transportation system for zero-gravity environment. System carries materials and parts between locations on space station. Includes tubular rails instead of open channels usually found in overhead conveyor systems. Since resistance to torque of closed tube greater than that of open channel for same amount of material, tubular monorail designed for higher loads or for greater spacing between support points.

Hydrogen Purification and Recycling for an Integrated Oxygen Recovery System Architecture

Science.gov (United States)

Abney, Morgan B.; Greenwood, Zachary; Wall, Terry; Miller, Lee; Wheeler, Ray

2016-01-01

The United States Atmosphere Revitalization life support system on the International Space Station (ISS) performs several services for the crew including oxygen generation, trace contaminant control, carbon dioxide (CO2) removal, and oxygen recovery. Oxygen recovery is performed using a Sabatier reactor developed by Hamilton Sundstrand, wherein CO2 is reduced with hydrogen in a catalytic reactor to produce methane and water. The water product is purified in the Water Purification Assembly and recycled to the Oxygen Generation Assembly (OGA) to provide O2 to the crew. This architecture results in a theoretical maximum oxygen recovery from CO2 of approximately 54% due to the loss of reactant hydrogen in Sabatier-produced methane that is currently vented outside of ISS. Plasma Methane Pyrolysis technology (PPA), developed by Umpqua Research Company, provides the capability to further close the Atmosphere Revitalization oxygen loop by recovering hydrogen from Sabatier-produced methane. A key aspect of this technology approach is to purify the hydrogen from the PPA product stream which includes acetylene, unreacted methane and byproduct water and carbon monoxide. In 2015, four sub-scale hydrogen separation systems were delivered to NASA for evaluation. These included two electrolysis single-cell hydrogen purification cell stacks developed by Sustainable Innovations, LLC, a sorbent-based hydrogen purification unit using microwave power for sorbent regeneration developed by Umpqua Research Company, and a LaNi4.6Sn0.4 metal hydride produced by Hydrogen Consultants, Inc. Here we report the results of these evaluations, discuss potential architecture options, and propose future work.

Heat transport system

International Nuclear Information System (INIS)

Pierce, B.L.

1978-01-01

A heat transport system of small size which can be operated in any orientation consists of a coolant loop containing a vaporizable liquid as working fluid and includes in series a vaporizer, a condenser and two one-way valves and a pressurizer connected to the loop between the two valves. The pressurizer may be divided into two chambers by a flexible diaphragm, an inert gas in one chamber acts as a pneumatic spring for the system. This system is suitable for use in a nuclear-powered artificial heart

Solutions to Improve Person Transport System in the Pitesti City by Analyzing Public Transport vs. Private Transport

Science.gov (United States)

Mihaela, Istrate; Alexandru, Boroiu; Viorel, Nicolae; Ionel, Vieru

2017-10-01

One of the major problems facing the Pitesti city is the road congestion that occurs in the central area of the city during the peak hours. With all the measures taken in recent years - the widening of road arteries, increasing the number of parking spaces, the creation of overground road passages - it is obvious that the problem can only be solved by a new philosophy regarding urban mobility: it is no longer possible to continue through solutions to increase the accessibility of the central area of the city, but it is necessary, on the contrary, to promote a policy of discouraging the penetration of vehicles in the city center, coupled with a policy of improving the connection between urban public transport and county public transport. This new approach is also proposed in the new Urban Mobility Plan of Pitesti city, under development. The most convincing argument for the necessity of this new orientation in the Pitesti city mobility plan is based on the analysis of the current situation of passenger transport on the territory of Pitesti city: the analysis of “public transport versus private transport” reveals a very low occupancy rate for cars and the fact that the road surface required for a passenger (the dynamic area) is much higher in the case of private transport than in the case of public transport. Measurements of passenger flows and vehicle flows on the 6 penetration ways in the city have been made and the calculations clearly demonstrate the benefits of an urban public transport system connected by “transshipment buses” to be made at the edge of the city, to the county public transport system. In terms of inter-county transport, it will continue to be connected to the urban public transport system by existing bus Station, within the city: South Bus Station and North Bus Station. The usefulness of the paper is that it identifies the solutions for sustainable mobility in Pitesti city and proposes concrete solutions for the development of the

Oxygen-Dependent Transcriptional Regulator Hap1p Limits Glucose Uptake by Repressing the Expression of the Major Glucose Transporter Gene RAG1 in Kluyveromyces lactis▿

Science.gov (United States)

Bao, Wei-Guo; Guiard, Bernard; Fang, Zi-An; Donnini, Claudia; Gervais, Michel; Passos, Flavia M. Lopes; Ferrero, Iliana; Fukuhara, Hiroshi; Bolotin-Fukuhara, Monique

2008-01-01

The HAP1 (CYP1) gene product of Saccharomyces cerevisiae is known to regulate the transcription of many genes in response to oxygen availability. This response varies according to yeast species, probably reflecting the specific nature of their oxidative metabolism. It is suspected that a difference in the interaction of Hap1p with its target genes may explain some of the species-related variation in oxygen responses. As opposed to the fermentative S. cerevisiae, Kluyveromyces lactis is an aerobic yeast species which shows different oxygen responses. We examined the role of the HAP1-equivalent gene (KlHAP1) in K. lactis. KlHap1p showed a number of sequence features and some gene targets (such as KlCYC1) in common with its S. cerevisiae counterpart, and KlHAP1 was capable of complementing the hap1 mutation. However, the KlHAP1 disruptant showed temperature-sensitive growth on glucose, especially at low glucose concentrations. At normal temperature, 28°C, the mutant grew well, the colony size being even greater than that of the wild type. The most striking observation was that KlHap1p repressed the expression of the major glucose transporter gene RAG1 and reduced the glucose uptake rate. This suggested an involvement of KlHap1p in the regulation of glycolytic flux through the glucose transport system. The ΔKlhap1 mutant showed an increased ability to produce ethanol during aerobic growth, indicating a possible transformation of its physiological property to Crabtree positivity or partial Crabtree positivity. Dual roles of KlHap1p in activating respiration and repressing fermentation may be seen as a basis of the Crabtree-negative physiology of K. lactis. PMID:18806211

Integrated Intermodal Passenger Transportation System

Science.gov (United States)

Klock, Ryan; Owens, David; Schwartz, Henry; Plencner, Robert

2012-01-01

Modern transportation consists of many unique modes of travel. Each of these modes and their respective industries has evolved independently over time, forming a largely incoherent and inefficient overall transportation system. Travelers today are forced to spend unnecessary time and efforts planning a trip through varying modes of travel each with their own scheduling, pricing, and services; causing many travelers to simply rely on their relatively inefficient and expensive personal automobile. This paper presents a demonstration program system to not only collect and format many different sources of trip planning information, but also combine these independent modes of travel in order to form optimal routes and itineraries of travel. The results of this system show a mean decrease in inter-city travel time of 10 percent and a 25 percent reduction in carbon dioxide emissions over personal automobiles. Additionally, a 55 percent reduction in carbon dioxide emissions is observed for intra-city travel. A conclusion is that current resources are available, if somewhat hidden, to drastically improve point to point transportation in terms of time spent traveling, the cost of travel, and the ecological impact of a trip. Finally, future concepts are considered which could dramatically improve the interoperability and efficiency of the transportation infrastructure.

Effectiveness of work zone intelligent transportation systems.

Science.gov (United States)

2013-12-01

In the last decade, Intelligent Transportation Systems (ITS) have increasingly been deployed in work zones by state departments of transportation. Also known as smart work zone systems they improve traffic operations and safety by providing real-time...

Cardiovascular oxygen transport limitations to thermal niche expansion and the role of environmental Po2 in Antarctic notothenioid fishes.

Science.gov (United States)

Buckley, Bradley A; Hedrick, Michael S; Hillman, Stanley S

2014-01-01

The notothenioid fishes of the Southern Ocean possess some of the lowest upper thermal thresholds of any species and display a range of cardiovascular features that distinguish them from other fishes. Some species lack hemoglobin, and it has been posited that the inability to deliver sufficient oxygen at elevated temperature may in part determine upper thermal thresholds. Here, we provide an analysis of systemic O2 transport based on circulatory resistance, cardiac outputs, and cardiac power for three species of Antarctic fishes, including species that possess hemoglobin (Trematomus bernacchii, Pagothenia borchgrevinki) and a species lacking hemoglobin (Chaenocephalus aceratus) and that differ in their cardiovascular characteristics. This analysis supports the hypothesis that the mutation resulting in the lack of hemoglobin would be metabolically prohibitive at elevated temperatures. The analysis also suggests that such a mutation would be least detrimental to species with greater cardiac power outputs and lower total peripheral resistance. Decreased environmental Po2 has the greatest detrimental effect on the metabolic capacity in the species without hemoglobin. These data indicate that differences in cardiovascular characteristics of the notothenioid fishes place varying limits on thermal niche expansion in these species, but any significant increase in environmental temperature or decrease in environmental Po2 will prohibit maintenance of cardiovascular systemic O2 transport in all species. These data also suggest an evolutionary sequence of events such that a reduction in hematocrit, to reduce blood viscosity and resistance, was a first step in the invasion of low-temperature habitats and loss of hemoglobin was followed by increased cardiac power output to achieve sustainable metabolic rates.

Nonlinear transport of dynamic system phase space

International Nuclear Information System (INIS)

Xie Xi; Xia Jiawen

1993-01-01

The inverse transform of any order solution of the differential equation of general nonlinear dynamic systems is derived, realizing theoretically the nonlinear transport for the phase space of nonlinear dynamic systems. The result is applicable to general nonlinear dynamic systems, with the transport of accelerator beam phase space as a typical example

Calculations of oscillation spectra of disordered interstitial solid solutions of vanadium-oxygen system

International Nuclear Information System (INIS)

Danilkin, S.A.

1978-01-01

The frequency spectra calculation of disordered solid interstitial solutions of a vanadium-oxygen system for oxygen concentration of 5.9% and 15.8% (V 16 O and V 16 O 3 ) is carried out. The axially-symmetric model of crystal lattice dinamics with consideration of vanadium-oxygen and vanadium-vanadium interactions up to the second coordination sphere is used. On the whole, the obtained spectra are in qualitative agreement with experiment and reflect correctly all the changes in frequency spectra of pure vanadium on doping with oxygen

Rail transport systems approach

CERN Document Server

2017-01-01

This book shows how the systems approach is employed by scientists in various countries to solve specific problems concerning railway transport. In particular, the book describes the experiences of scientists from Romania, Germany, the Czech Republic, the UK, Russia, Ukraine, Lithuania and Poland. For many of these countries there is a problem with the historical differences between the railways. In particular, there are railways with different rail gauges, with different signaling and communication systems, with different energy supplies and, finally, with different political systems, which are reflected in the different approaches to the management of railway economies. The book’s content is divided into two main parts, the first of which provides a systematic analysis of individual means of providing and maintaining rail transport. In turn, the second part addresses infrastructure and management development, with particular attention to security issues. Though primarily written for professionals involved...

Indirect Liquefaction of Biomass to Transportation Fuels Via Mixed Oxygenated Intermediates

Energy Technology Data Exchange (ETDEWEB)

Tan, Eric C.D.

2016-11-14

This paper presents a comparative techno-economic analysis of four emerging conversion pathways from biomass to gasoline-, jet-, and diesel-range hydrocarbons via indirect liquefaction with specific focus on pathways utilizing oxygenated intermediates. The processing steps include: biomass-to-syngas via indirect gasification, gas cleanup, conversion of syngas to alcohols/oxygenates followed by conversion of alcohols/oxygenates to hydrocarbon blendstocks via dehydration, oligomerization, and hydrogenation.

Transportation system requirements document. Revision 1 DCN01. Supplement

International Nuclear Information System (INIS)

1995-05-01

The original Transportation System Requirements Document described the functions to be performed by and the technical requirements for the Transportation System to transport spent nuclear fuel (SNF) and high-level radioactive waste (HLW) from Purchaser and Producer sites to a Civilian Radioactive Waste Management System (CRWMS) site, and between CRWMS sites. The purpose of that document was to define the system-level requirements. These requirements include design and operations requirements to the extent they impact on the development of the physical segments of Transportation. The document also presented an overall description of Transportation, its functions, its segments, and the requirements allocated to the segments and the system-level interfaces with Transportation. This revision of the document contains only the pages that have been modified

The transport system approval concept

International Nuclear Information System (INIS)

Pettersson, B.G.

1991-01-01

The needs for, and merits of, a new concept for the safety assessment and approval of shipments of radioactive materials is introduced and discussed. The purpose of the new concept is to enable and encourage integration of analysis and review of transport safety with similar safety analysis and review of the handling operations involving the radioactive material at the despatching and receiving ends of a shipment. Safety contributing elements or functions of the means of transport (the Transport System) can thus readily be taken into account in the assessment. The objective is to avoid constraints -experienced or potential - introduced by the package functional provisions contained in the transport regulations, whilst maintaining safety during transport, as well as during facility handling operations, at least at the level at the level currently established. (author)

The WIPP transportation system: Dedicated to safety

International Nuclear Information System (INIS)

Ward, T.; McFadden, M.

1993-01-01

When developing a transportation system to transport transuranic (TRU) waste from ten widely-dispersed generator sites, the Department of Energy (DOE) recognized and addressed many challenges. Shipments of waste to the Waste Isolation Pilot Plant (WIPP) were to cover a twenty-five year period and utilize routes covering over twelve thousand miles in twenty-three states. Enhancing public safety by maximizing the payload, thus reducing the number of shipments, was the primary objective. To preclude the requirement for overweight permits, the DOE started with a total shipment weight limit of 80,000 pounds and developed an integrated transportation system consisting of a Type ''B'' package to transport the material, a lightweight tractor and trailer, stringent driver requirements, and a shipment tracking system referred to as ''TRANSCOM''

Pilot-scale incineration testing of an oxygen-enhanced combustion system

International Nuclear Information System (INIS)

Waterland, L.R.; Lee, J.W.; Staley, L.J.

1989-01-01

This paper discusses a series of demonstration tests of the American Combustion, Inc., Thermal Destruction System performed under the Superfund innovative technology evaluation (SITE) program. This oxygen-enhanced combustion system was retrofit to the pilot-scale rotary kiln incinerator at EPA's Combustion Research Facility. This system's performance was tested firing contaminated soil from the Stringfellow Superfund Site, both alone and mixed with a hazardous coal tar waste (decanter tank tar sludge form coking operations - K087). Comparative performance with conventional incinerator operation was tested. Test results show that compliance with the hazardous waste incinerator performance standards of 99.99 percent principal organic hazardous constituent (POHC) destruction and removal efficiency (DRE) and particulate emissions of less than 180 mg/dscm at 7 percent O 2 was achieved for all tests. The Pyretron oxygen-enhanced combustion system allowed in-compliance operation at double the mixed waste feedrate possible with conventional incineration, and with a 60 percent increase in charge weight than possible with conventional incineration

Numerical Modelling Approaches for Sediment Transport in Sewer Systems

DEFF Research Database (Denmark)

Mark, Ole

A study of the sediment transport processes in sewers has been carried out. Based on this study a mathematical modelling system has been developed to describe the transport processes of sediments and dissolved matter in sewer systems. The modelling system consists of three sub-models which...... constitute the basic modelling system necessary to give a discription of the most dominant physical transport processes concerning particles and dissolved matter in sewer systems: A surface model. An advection-dispersion model. A sediment transport model....

Third-order TRANSPORT: A computer program for designing charged particle beam transport systems

International Nuclear Information System (INIS)

Carey, D.C.; Brown, K.L.; Rothacker, F.

1995-05-01

TRANSPORT has been in existence in various evolutionary versions since 1963. The present version of TRANSPORT is a first-, second-, and third-order matrix multiplication computer program intended for the design of static-magnetic beam transport systems. This report discusses the following topics on TRANSPORT: Mathematical formulation of TRANSPORT; input format for TRANSPORT; summaries of TRANSPORT elements; preliminary specifications; description of the beam; physical elements; other transformations; assembling beam lines; operations; variation of parameters for fitting; and available constraints -- the FIT command

Intelligent Transportation Systems : critical standards

Science.gov (United States)

1999-06-01

Intelligent Transportation Systems (ITS) standards are industry-consensus standards that provide the details about how different systems interconnect and communicate information to deliver the ITS user services described in the National ITS Architect...

A theoretical evaluation of the oxygen concentration in a corrosion-fatigue crack

International Nuclear Information System (INIS)

Turnbull, A.

1981-01-01

The oxygen concentration in a corrosion-fatigue crack has been evaluated theoretically by assuming that oxygen was consumed by cathodic reduction on the walls of the crack and mass transport occurred by diffusion and advection (forced convection), with the latter resulting from the sinusoidal variation of the displacement of the crack walls. By using parameters relevant to a compact tension specimen, the time-dependent distribution of the oxygen concentration in the crack was calculated as a function of ΔK (the range of the stress intensity factor), R-value (minimum load/maximum load), frequency, crack length, and electrode potential. The influence of advection was to significantly enhance the mass transport of oxygen in the crack compared with ''diffusion-only'' even at low frequencies and low ΔK. Regions in the crack were identified in which advection dominance or diffusion dominance of the mass transport of oxygen occurred

Aircraft Oxygen Generation

Science.gov (United States)

2012-02-01

An Oxygen Enriched Air System for the AV-8A Harrier (NADC-81198-60).” 70 Horch , T., et. al. “The F-16 Onboard Oxygen Generating System: Performance...Only and Safety Privileged). Horch , T., Miller, R., Bomar, J., Tedor, J., Holden, R., Ikels, K., & Lozano, P. (1983). The F-16 Onboard Oxygen

Innovative oxide materials for electrochemical energy conversion and oxygen separation

Science.gov (United States)

Belousov, V. V.

2017-10-01

Ion-conducting solid metal oxides are widely used in high-temperature electrochemical devices for energy conversion and oxygen separation. However, liquid metal oxides possessing unique electrochemical properties still remain of limited use. The review demonstrates the potential for practical applications of molten oxides. The transport properties of molten oxide materials are discussed. The emphasis is placed on the chemical diffusion of oxygen in the molten oxide membrane materials for electrochemical energy conversion and oxygen separation. The thermodynamics of these materials is considered. The dynamic polymer chain model developed to describe the oxygen ion transport in molten oxides is discussed. Prospects for further research into molten oxide materials are outlined. The bibliography includes 145 references.

Performances of the HL (Hyperloop) transport system

OpenAIRE

van Goeverden, C.D.; Milakis, D.; Janic, M.; Konings, J.W.; Cools, M.; Limbourg, S.

2017-01-01

This paper deals with an analysis of performances of the HL (Hyperloop) transport system considered as an advanced transport alternative to the existing APT (Air Passenger Transport) and HSR (High Speed Rail) systems. The considered performances are operational, financial, social and environmental. The operational performance include capacity and quality of service provided to the system’s users-passengers with attributes such as door-to-door travel time consisting of the access and egress ti...

Development and Integration of the Janus Robotic Lander: A Liquid Oxygen-Liquid Methane Propulsion System Testbed

Science.gov (United States)

Ponce, Raul

Initiatives have emerged with the goal of sending humans to other places in our solar system. New technologies are being developed that will allow for more efficient space systems to transport future astronauts. One of those technologies is the implementation of propulsion systems that use liquid oxygen and liquid methane (LO2-LCH4) as propellants. The benefits of a LO2-LCH4 propulsion system are plenty. One of the main advantages is the possibility of manufacturing the propellants at the destination body. A space vehicle which relies solely on liquid oxygen and liquid methane for its main propulsion and reaction control engines is necessary to exploit this advantage. At the University of Texas at El Paso (UTEP) MIRO Center for Space Exploration Technology Research (cSETR) such a vehicle is being developed. Janus is a robotic lander vehicle with the capability of vertical take-off and landing (VTOL) which integrates several LO2-LCH 4 systems that are being devised in-house. The vehicle will serve as a testbed for the parallel operation of these propulsion systems while being fed from common propellant tanks. The following work describes the efforts done at the cSETR to develop the first prototype of the vehicle as well as the plan to move forward in the design of the subsequent prototypes that will lead to a flight vehicle. In order to ensure an eventual smooth integration of the different subsystems that will form part of Janus, requirements were defined for each individual subsystem as well as the vehicle as a whole. Preliminary testing procedures and layouts have also been developed and will be discussed to detail in this text. Furthermore, the current endeavors in the design of each subsystem and the way that they interact with one another within the lander will be explained.

Advanced public transportation systems benefits

Science.gov (United States)

1996-03-01

Benefits and cost savings for various Advanced Public Transportation Systems are outlined here. Operational efficiencies are given for Transit Management Systems in different locales, as well as compliant resolution and safety. Electronic Fare Paymen...

Optimal concentrations in transport systems

Science.gov (United States)

Jensen, Kaare H.; Kim, Wonjung; Holbrook, N. Michele; Bush, John W. M.

2013-01-01

Many biological and man-made systems rely on transport systems for the distribution of material, for example matter and energy. Material transfer in these systems is determined by the flow rate and the concentration of material. While the most concentrated solutions offer the greatest potential in terms of material transfer, impedance typically increases with concentration, thus making them the most difficult to transport. We develop a general framework for describing systems for which impedance increases with concentration, and consider material flow in four different natural systems: blood flow in vertebrates, sugar transport in vascular plants and two modes of nectar drinking in birds and insects. The model provides a simple method for determining the optimum concentration copt in these systems. The model further suggests that the impedance at the optimum concentration μopt may be expressed in terms of the impedance of the pure (c = 0) carrier medium μ0 as μopt∼2αμ0, where the power α is prescribed by the specific flow constraints, for example constant pressure for blood flow (α = 1) or constant work rate for certain nectar-drinking insects (α = 6). Comparing the model predictions with experimental data from more than 100 animal and plant species, we find that the simple model rationalizes the observed concentrations and impedances. The model provides a universal framework for studying flows impeded by concentration, and yields insight into optimization in engineered systems, such as traffic flow. PMID:23594815

The Integrated Air Transportation System Evaluation Tool

Science.gov (United States)

Wingrove, Earl R., III; Hees, Jing; Villani, James A.; Yackovetsky, Robert E. (Technical Monitor)

2002-01-01

Throughout U.S. history, our nation has generally enjoyed exceptional economic growth, driven in part by transportation advancements. Looking forward 25 years, when the national highway and skyway systems are saturated, the nation faces new challenges in creating transportation-driven economic growth and wealth. To meet the national requirement for an improved air traffic management system, NASA developed the goal of tripling throughput over the next 20 years, in all weather conditions while maintaining safety. Analysis of the throughput goal has primarily focused on major airline operations, primarily through the hub and spoke system.However, many suggested concepts to increase throughput may operate outside the hub and spoke system. Examples of such concepts include the Small Aircraft Transportation System, civil tiltrotor, and improved rotorcraft. Proper assessment of the potential contribution of these technologies to the domestic air transportation system requires a modeling capability that includes the country's numerous smaller airports, acting as a fundamental component of the National Air space System, and the demand for such concepts and technologies. Under this task for NASA, the Logistics Management Institute developed higher fidelity demand models that capture the interdependence of short-haul air travel with other transportation modes and explicitly consider the costs of commercial air and other transport modes. To accomplish this work, we generated forecasts of the distribution of general aviation based aircraft and GA itinerant operations at each of nearly 3.000 airport based on changes in economic conditions and demographic trends. We also built modules that estimate the demand for travel by different modes, particularly auto, commercial air, and GA. We examined GA demand from two perspectives: top-down and bottom-up, described in detail.

Oxygen Consumption of Tilapia and Preliminary Mass Flows through a Prototype Closed Aquaculture System

Science.gov (United States)

Muller, Matthew S.; Bauer, Clarence F.

1994-01-01

Performance of NASA's prototype CELSS Breadboard Project Closed Aquaculture System was evaluated by estimating gas exchange quantification and preliminary carbon and nitrogen balances. The total system oxygen consumption rate was 535 mg/hr kg/fish (cv = 30%) when stocked with Tilapia aurea populations (fresh weights of 97 +/- 19 to 147 +/- 36 g/fish for various trials). Oxygen consumption by T. aurea (260 mg/hr kg/fish) contributed to approximately one-half of total system demand. Continuous carbon dioxide quantification methods were analyzed using the,relation of carbon dioxide to oxygen consumption. Overall food conversion rates averaged 18.2 +/- 3.2%. Major pathways for nitrogen and carbon in the system were described with preliminary mass closure of 60-80% and 60% for nitrogen and carbon.

System analysis of dry black liquor gasification based synthetic gas production comparing oxygen and air blown gasification systems

International Nuclear Information System (INIS)

Naqvi, Muhammad; Yan, Jinyue; Dahlquist, Erik

2013-01-01

Highlights: ► Circulating fluidized bed system for black liquor gasification with direct causticization. ► Effects of gasifying medium i.e. oxygen or air, on gasification are studied. ► Direct causticization eliminates energy intensive limekiln reducing biomass use. ► Results show 10% higher SNG production from O 2 blown system than air blown system. ► SNG production is higher in O 2 blown system than air blown system. - Abstract: The black liquor gasification based bio-fuel production at chemical pulp mill is an attractive option to replace conventional recovery boilers increasing system energy efficiency. The present paper studies circulating fluidized bed system with direct causticization using TiO 2 for the gasification of the black liquor to the synthesis gas. The advantage of using direct causticization is the elimination of energy-intensive lime kiln which is an integral part of the conventional black liquor recovery system. The study evaluates the effects of gasifying medium i.e. oxygen or air, on the fluidized bed gasification system, the synthesis gas composition, and the downstream processes for the synthesis gas conversion to the synthetic natural gas (SNG). The results showed higher synthetic natural gas production potential with about 10% higher energy efficiency using oxygen blown gasification system than the air blown system. From the pulp mill integration perspective, the material and energy balance results in better integration of air blown system than the oxygen blown system, e.g. less steam required to be generated in the power boiler, less electricity import, and less additional biomass requirement. However, the air blown system still requires a significant amount of energy in terms of the synthesis gas handling and gas upgrading using the nitrogen rejection system

The SIMPSONS project: An integrated Mars transportation system

Science.gov (United States)

Kaplan, Matthew; Carlson, Eric; Bradfute, Sherie; Allen, Kent; Duvergne, Francois; Hernandez, Bert; Le, David; Nguyen, Quan; Thornhill, Brett

In response to the Request for Proposal (RFP) for an integrated transportation system network for an advanced Martian base, Frontier Transportation Systems (FTS) presents the results of the SIMPSONS project (Systems Integration for Mars Planetary Surface Operations Networks). The following topics are included: the project background, vehicle design, future work, conclusions, management status, and cost breakdown. The project focuses solely on the surface-to-surface transportation at an advanced Martian base.

Integrated transport and renewable energy systems

DEFF Research Database (Denmark)

Mathiesen, B.V.; Lund, H.; Nørgård, Per Bromand

2007-01-01

Governments worldwide aim at reducing CO2 emissions and expanding renewable energy. A key element in achieving such a goal is to use renewable energy in transport such as biofuels. However, efforts to promote single transport technologies and single fuels only represent a partial solution...... transport. It is concluded that a 100 per cent renewable energy transport system is possible but is connected to significant challenges in the path towards it. Biomass is a limited resource and it is important to avoid effecting the production. The integration of the transport with the remaining energy....... No single technology can solve the problem of ever increasing CO2 emissions from transport. Transport must be integrated into energy planning, as electricity and heating. In this paper, a coherent effort to integrate transport into energy planning is proposed, using multiple means promoting sustainable...

Behavior of oxygen impurities in tokamak. Vol. 2

Energy Technology Data Exchange (ETDEWEB)

El-Sharif, R N; Beket, A H [Plasma and Nuclear Fusion Department, Nuclear Research Center, Atomic Energy Aurhority, Cairo (Egypt)

1996-03-01

Impurity transport in tokamak plasma is a subject of great importance in present day tokamak experiments. The transport of oxygen as an impurity element in small tokamak was studied theoretically. The viscosity coefficient of oxygen has been calculated in different approximation 13 and 21 moment approximation, taking into consideration {chi}>>1,{chi}{omega}{sub c} {tau}. It was found that in 21 moment approximation additional terms added to the perturbation from equilibrium leads to increase in viscosity coefficients than in 13 moments approximation. 9 figs.

Transport Coefficients for dense hard-disk systems

NARCIS (Netherlands)

Garcia-Rojo, R.; Luding, Stefan; Brey, J. Javier; Ooms, G.; Hoogendoorn, C.J.

2007-01-01

A study of the transport coefficients of a system of elastic hard disks, based on the use of Helfand-Einstein expressions is reported. The pressure, the viscosity, and the heat conductivity are examined for different density and system-size. While most transport coefficients agree with Enskog theory

A revolutionary lunar space transportation system architecture using extraterrestrial LOX-augmented NTR propulsion

Science.gov (United States)

Borowski, Stanley K.; Corban, Robert R.; Culver, Donald W.; Bulman, Melvin J.; McIlwain, Mel C.

1994-08-01

The concept of a liquid oxygen (LOX)-augmented nuclear thermal rocket (NTR) engine is introduced, and its potential for revolutionizing lunar space transportation system (LTS) performance using extraterrestrial 'lunar-derived' liquid oxygen (LUNOX) is outlined. The LOX-augmented NTR (LANTR) represents the marriage of conventional liquid hydrogen (LH2)-cooled NTR and airbreathing engine technologies. The large divergent section of the NTR nozzle functions as an 'afterburner' into which oxygen is injected and supersonically combusted with nuclear preheated hydrogen emerging from the NTR's choked sonic throat: 'scramjet propulsion in reverse.' By varying the oxygen-to-fuel mixture ratio (MR), the LANTR concept can provide variable thrust and specific impulse (Isp) capability with a LH2-cooled NTR operating at relatively constant power output. For example, at a MR = 3, the thrust per engine can be increased by a factor of 2.75 while the Isp decreases by only 30 percent. With this thrust augmentation option, smaller, 'easier to develop' NTR's become more acceptable from a mission performance standpoint (e.g., earth escape gravity losses are reduced and perigee propulsion requirements are eliminated). Hydrogen mass and volume is also reduced resulting in smaller space vehicles. An evolutionary NTR-based lunar architecture requiring only Shuttle C and/or 'in-line' shuttle-derived launch vehicles (SDV's) would operate initially in an 'expandable mode' with NTR lunar transfer vehicles (LTV's) delivering 80 percent more payload on piloted missions than their LOX/LH2 chemical propulsion counterparts. With the establishment of LUNOX production facilities on the lunar surface and 'fuel/oxidizer' depot in low lunar orbit (LLO), monopropellant NTR's would be outfitted with an oxygen propellant module, feed system, and afterburner nozzle for 'bipropellant' operation. The LANTR cislunar LTV now transitions to a reusable mode with smaller vehicle and payload doubling benefits on

Solute carrier transporters: potential targets for digestive system neoplasms.

Science.gov (United States)

Xie, Jing; Zhu, Xiao Yan; Liu, Lu Ming; Meng, Zhi Qiang

2018-01-01

Digestive system neoplasms are the leading causes of cancer-related death all over the world. Solute carrier (SLC) superfamily is composed of a series of transporters that are ubiquitously expressed in organs and tissues of digestive systems and mediate specific uptake of small molecule substrates in facilitative manner. Given the important role of SLC proteins in maintaining normal functions of digestive system, dysregulation of these protein in digestive system neoplasms may deliver biological and clinical significance that deserves systemic studies. In this review, we critically summarized the recent advances in understanding the role of SLC proteins in digestive system neoplasms. We highlighted that several SLC subfamilies, including metal ion transporters, transporters of glucose and other sugars, transporters of urea, neurotransmitters and biogenic amines, ammonium and choline, inorganic cation/anion transporters, transporters of nucleotide, amino acid and oligopeptide organic anion transporters, transporters of vitamins and cofactors and mitochondrial carrier, may play important roles in mediating the initiation, progression, metastasis, and chemoresistance of digestive system neoplasms. Proteins in these SLC subfamilies may also have diagnostic and prognostic values to particular cancer types. Differential expression of SLC proteins in tumors of digestive system was analyzed by extracting data from human cancer database, which revealed that the roles of SLC proteins may either be dependent on the substrates they transport or be tissue specific. In addition, small molecule modulators that pharmacologically regulate the functions of SLC proteins were discussed for their possible application in the treatment of digestive system neoplasms. This review highlighted the potential of SLC family proteins as drug target for the treatment of digestive system neoplasms.

Propagating fronts in reaction-transport systems with memory

Energy Technology Data Exchange (ETDEWEB)

Yadav, A. [Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314 (United States)], E-mail: ayadav1@lsu.edu; Fedotov, Sergei [School of Mathematics, University of Manchester, Manchester M60 1DQ (United Kingdom)], E-mail: sergei.fedotov@manchester.ac.uk; Mendez, Vicenc [Grup de Fisica Estadistica, Departament de Fisica, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)], E-mail: vicenc.mendez@uab.es; Horsthemke, Werner [Department of Chemistry, Southern Methodist University, Dallas, TX 75275-0314 (United States)], E-mail: whorsthe@smu.edu

2007-11-26

In reaction-transport systems with non-standard diffusion, the memory of the transport causes a coupling of reactions and transport. We investigate the effect of this coupling for systems with Fisher-type kinetics and obtain a general analytical expression for the front speed. We apply our results to the specific case of subdiffusion.

A lithium–oxygen battery with a long cycle life in an air-like atmosphere

Science.gov (United States)

Asadi, Mohammad; Sayahpour, Baharak; Abbasi, Pedram; Ngo, Anh T.; Karis, Klas; Jokisaari, Jacob R.; Liu, Cong; Narayanan, Badri; Gerard, Marc; Yasaei, Poya; Hu, Xuan; Mukherjee, Arijita; Lau, Kah Chun; Assary, Rajeev S.; Khalili-Araghi, Fatemeh; Klie, Robert F.; Curtiss, Larry A.; Salehi-Khojin, Amin

2018-03-01

Lithium–air batteries are considered to be a potential alternative to lithium-ion batteries for transportation applications, owing to their high theoretical specific energy. So far, however, such systems have been largely restricted to pure oxygen environments (lithium–oxygen batteries) and have a limited cycle life owing to side reactions involving the cathode, anode and electrolyte. In the presence of nitrogen, carbon dioxide and water vapour, these side reactions can become even more complex. Moreover, because of the need to store oxygen, the volumetric energy densities of lithium–oxygen systems may be too small for practical applications. Here we report a system comprising a lithium carbonate-based protected anode, a molybdenum disulfide cathode and an ionic liquid/dimethyl sulfoxide electrolyte that operates as a lithium–air battery in a simulated air atmosphere with a long cycle life of up to 700 cycles. We perform computational studies to provide insight into the operation of the system in this environment. This demonstration of a lithium–oxygen battery with a long cycle life in an air-like atmosphere is an important step towards the development of this field beyond lithium-ion technology, with a possibility to obtain much higher specific energy densities than for conventional lithium-ion batteries.

A lithium-oxygen battery with a long cycle life in an air-like atmosphere.

Science.gov (United States)

Asadi, Mohammad; Sayahpour, Baharak; Abbasi, Pedram; Ngo, Anh T; Karis, Klas; Jokisaari, Jacob R; Liu, Cong; Narayanan, Badri; Gerard, Marc; Yasaei, Poya; Hu, Xuan; Mukherjee, Arijita; Lau, Kah Chun; Assary, Rajeev S; Khalili-Araghi, Fatemeh; Klie, Robert F; Curtiss, Larry A; Salehi-Khojin, Amin

2018-03-21

Lithium-air batteries are considered to be a potential alternative to lithium-ion batteries for transportation applications, owing to their high theoretical specific energy. So far, however, such systems have been largely restricted to pure oxygen environments (lithium-oxygen batteries) and have a limited cycle life owing to side reactions involving the cathode, anode and electrolyte. In the presence of nitrogen, carbon dioxide and water vapour, these side reactions can become even more complex. Moreover, because of the need to store oxygen, the volumetric energy densities of lithium-oxygen systems may be too small for practical applications. Here we report a system comprising a lithium carbonate-based protected anode, a molybdenum disulfide cathode and an ionic liquid/dimethyl sulfoxide electrolyte that operates as a lithium-air battery in a simulated air atmosphere with a long cycle life of up to 700 cycles. We perform computational studies to provide insight into the operation of the system in this environment. This demonstration of a lithium-oxygen battery with a long cycle life in an air-like atmosphere is an important step towards the development of this field beyond lithium-ion technology, with a possibility to obtain much higher specific energy densities than for conventional lithium-ion batteries.

Characterization of water quality and simulation of temperature, nutrients, biochemical oxygen demand, and dissolved oxygen in the Wateree River, South Carolina, 1996-98

Science.gov (United States)

Feaster, Toby D.; Conrads, Paul

2000-01-01

In May 1996, the U.S. Geological Survey entered into a cooperative agreement with the Kershaw County Water and Sewer Authority to characterize and simulate the water quality in the Wateree River, South Carolina. Longitudinal profiling of dissolved-oxygen concentrations during the spring and summer of 1996 revealed dissolved-oxygen minimums occurring upstream from the point-source discharges. The mean dissolved-oxygen decrease upstream from the effluent discharges was 2.0 milligrams per liter, and the decrease downstream from the effluent discharges was 0.2 milligram per liter. Several theories were investigated to obtain an improved understanding of the dissolved-oxygen dynamics in the upper Wateree River. Data suggest that the dissolved-oxygen concentration decrease is associated with elevated levels of oxygen-consuming nutrients and metals that are flowing into the Wateree River from Lake Wateree. Analysis of long-term streamflow and water-quality data collected at two U.S. Geological Survey gaging stations suggests that no strong correlation exists between streamflow and dissolved-oxygen concentrations in the Wateree River. However, a strong negative correlation does exist between dissolved-oxygen concentrations and water temperature. Analysis of data from six South Carolina Department of Health and Environmental Control monitoring stations for 1980.95 revealed decreasing trends in ammonia nitrogen at all stations where data were available and decreasing trends in 5-day biochemical oxygen demand at three river stations. The influence of various hydrologic and point-source loading conditions on dissolved-oxygen concentrations in the Wateree River were determined by using results from water-quality simulations by the Branched Lagrangian Transport Model. The effects of five tributaries and four point-source discharges were included in the model. Data collected during two synoptic water-quality samplings on June 23.25 and August 11.13, 1997, were used to calibrate

Thermochemical conversion of biomass in smouldering combustion across scales: The roles of heterogeneous kinetics, oxygen and transport phenomena.

Science.gov (United States)

Huang, Xinyan; Rein, Guillermo

2016-05-01

The thermochemical conversion of biomass in smouldering combustion is investigated here by combining experiments and modeling at two scales: matter (1mg) and bench (100g) scales. Emphasis is put on the effect of oxygen (0-33vol.%) and oxidation reactions because these are poorly studied in the literature in comparison to pyrolysis. The results are obtained for peat as a representative biomass for which there is high-quality experimental data published previously. Three kinetic schemes are explored, including various steps of drying, pyrolysis and oxidation. The kinetic parameters are found using the Kissinger-Genetic Algorithm method, and then implemented in a one-dimensional model of heat and mass transfer. The predictions are validated with thermogravimetric and bench-scale experiments and then analyzed to unravel the role of heterogeneous reaction. This is the first time that the influence of oxygen on biomass smouldering is explained in terms of both chemistry and transport phenomena across scales. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Analysis and comparison of transportation security systems

International Nuclear Information System (INIS)

Rinne, R.L.

1976-05-01

The role of modeling in the analysis of transportation security systems is described. Various modeling approaches are outlined. The conflict model developed in Sandia Laboratories' Transportation Mode Analysis for the NRC Special Safeguards Study is used to demonstrate the capability of models to determine system sensitivities and compare alternatives

A radioactive waste transportation package monitoring system for normal transport and accident emergency response conditions

International Nuclear Information System (INIS)

Brown, G.S.; Cashwell, J.W.; Apple, M.L.

1993-01-01

This paper addresses spent fuel and high level waste transportation history and prospects, discusses accident histories of radioactive material transport, discusses emergency responder needs and provides a general description of the Transportation Intelligent Monitoring System (TRANSIMS) design. The key objectives of the monitoring system are twofold: (1) to facilitate effective emergency response to accidents involving a radioactive waste transportation package, while minimizing risk to the public and emergency first-response personnel, and (2) to allow remote monitoring of transportation vehicle and payload conditions to enable research into radioactive material transportation for normal and accident conditions. (J.P.N.)

Power Systems Development Facility Gasification Test Run TC08

Energy Technology Data Exchange (ETDEWEB)

Southern Company Services

2002-06-30

This report discusses Test Campaign TC08 of the Kellogg Brown & Root, Inc. (KBR) Transport Gasifier train with a Siemens Westinghouse Power Corporation (Siemens Westinghouse) particle filter system at the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama. The Transport Gasifier is an advanced circulating fluidized-bed gasifier designed to operate as either a combustor or a gasifier in air- or oxygen-blown mode using a particulate control device (PCD). The Transport Gasifier was operated as a pressurized gasifier in air- and oxygen-blown modes during TC08. Test Run TC08 was started on June 9, 2002 and completed on June 29. Both gasifier and PCD operations were stable during the test run with a stable baseline pressure drop. The oxygen feed supply system worked well and the transition from air to oxygen blown was smooth. The gasifier temperature was varied between 1,710 and 1,770 F at pressures from 125 to 240 psig. The gasifier operates at lower pressure during oxygen-blown mode due to the supply pressure of the oxygen system. In TC08, 476 hours of solid circulation and 364 hours of coal feed were attained with 153 hours of pure oxygen feed. The gasifier and PCD operations were stable in both enriched air and 100 percent oxygen blown modes. The oxygen concentration was slowly increased during the first transition to full oxygen-blown operations. Subsequent transitions from air to oxygen blown could be completed in less than 15 minutes. Oxygen-blown operations produced the highest synthesis gas heating value to date, with a projected synthesis gas heating value averaging 175 Btu/scf. Carbon conversions averaged 93 percent, slightly lower than carbon conversions achieved during air-blown gasification.

Development of metal catalyst impregnation technology for membrane-based oxygen removal system

International Nuclear Information System (INIS)

Kim, Mun Soo; Lee, Doo Ho; Kang, Duk Won

2005-01-01

Dissolved oxygen(DO) is a primary cause of PWSCC and its content in reactor coolant system in NPPs has been strictly controlled by various DO removal methods. There are several removal methods of DO, such as vacuum degasification, thermal deaeration, and reductive removal by oxygen scavengers. Although the operation principles of vacuum degasification and thermal deaeration are simple, these methods require a lot of energy for operation and show lower efficiency. And these methods have a few handicaps such as temperature, pH, toxicity, high cost of installation and so on. For the purpose of developing the best method for DO removal from make-up water storage tank, it is necessary to overcome the disadvantages of hydrazine treatment. From this point of view, membrane-based oxygen removal system (MORS) has many advantages than other methods for example, friendly environmental process, versatility of operation conditions with high temperature and low pressure, small space, low cost, etc. Recently de-gassing membrane is widely used in power plant's feed water system for DO removal. De-gassing membrane has some advantages; it removes other dissolved gases such as CO2, N2, as well as O2, and is more economical than Catalytic resin-based Oxygen Removal System. In this study, to obtain better efficiency of MORS, we modified the polypropylene (PP) hollow fiber membrane by plasma treatment and ion beam irradiation supported platinum(Pt), palladium(Pd) as metal catalyst on the surface of the membrane

TRANSFUSION RESTORES BLOOD VISCOSITY AND REINSTATES MICROVASCULAR CONDITIONS FROM HEMORRHAGIC SHOCK INDEPENDENT OF OXYGEN CARRYING CAPACITY

OpenAIRE

Cabrales, Pedro; Intaglietta, Marcos; Tsai, Amy G.

2007-01-01

Systemic and microvascular hemodynamic responses to transfusion of oxygen using functional and non-functional packed fresh red blood cells (RBCs) from hemorrhagic shock were studied in the hamster window chamber model to determine the significance of RBCs on rheological and oxygen transport properties. Moderate hemorrhagic shock was induced by arterial controlled bleeding of 50% of the blood volume, and a hypovolemic state was maintained for one hour. Volume restitution was performed by infus...

Maximum Plant Uptakes for Water, Nutrients, and Oxygen Are Not Always Met by Irrigation Rate and Distribution in Water-based Cultivation Systems

NARCIS (Netherlands)

Blok, Chris; Jackson, Brian E.; Guo, Xianfeng; Visser, De Pieter H.B.; Marcelis, Leo F.M.

2017-01-01

Growing on rooting media other than soils in situ -i.e., substrate-based growing- allows for higher yields than soil-based growing as transport rates of water, nutrients, and oxygen in substrate surpass those in soil. Possibly water-based growing allows for even higher yields as transport rates of

Aspects of transport system management within mining complex using information and telecommunication systems

Science.gov (United States)

Semykina, A. S.; Zagorodniy, N. A.; Konev, A. A.; Duganova, E. V.

2018-05-01

The paper considers aspects of transport system management within the mining complex. It indicates information and telecommunication systems that are used to increase transportation efficiency. It also describes key advantages and disadvantages. It is found that software products of the Modular Company used in pits allow increasing transport performance, minimizing losses and ensuring efficient transportation of minerals.

The role of sacrificial fugitives in thermoplastic extrusion feedstocks onproperties of MgO supports for oxygen transport membranes

DEFF Research Database (Denmark)

Kothanda Ramachandran, Dhavanesan; Kwok, Kawai; Søgaard, Martin

2015-01-01

2014AbstractThree different compositions of MgO compounds were investigated for use in oxygen transport membranes. Porous MgO supports were extruded using different kind (size, morphology and chemistry) of pore formers: A flaky graphite, a spherical graphite and ideal spheres of PMMA. The influence...... of the pore former on microstructure, gas permeation and the mechanical properties for various sintering temperatures were investigated.The gas permeation behavior of the MgO supports was highly dependent on pore neck size and total open porosity. MgO substrate, with 20% spherical graphite as a pore former...

Study on tracking system for radioactive material transport

Energy Technology Data Exchange (ETDEWEB)

Watanabe, F.; Igarashi, M.; Nomura, T. [Nuclear Emergency Assistance and Training Center, Japan Nuclear Cycle Development Inst., Ibaraki (Japan); Nakagome, Y. [Research Reactor Inst., Kyoto Univ., Osaka (Japan)

2004-07-01

When a transportation accident occurs, all entities including the shipper, the transportation organization, local governments, and emergency response organizations must have organized and planned for civil safety, property, and environmental protection. When a transportation accident occurs, many related organizations will be involved, and their cooperation determines the success or failure of the response. The point where the accident happens cannot be pinpointed in advance. Nuclear fuel transportation also requires a quick response from a viewpoint of security. A tracking system for radioactive material transport is being developed for use in Japan. The objective of this system is, in the rare event of an accident, for communication capabilities to share specific information among relevant organizations, the transporter, and so on.

Study on tracking system for radioactive material transport

International Nuclear Information System (INIS)

Watanabe, F.; Igarashi, M.; Nomura, T.; Nakagome, Y.

2004-01-01

When a transportation accident occurs, all entities including the shipper, the transportation organization, local governments, and emergency response organizations must have organized and planned for civil safety, property, and environmental protection. When a transportation accident occurs, many related organizations will be involved, and their cooperation determines the success or failure of the response. The point where the accident happens cannot be pinpointed in advance. Nuclear fuel transportation also requires a quick response from a viewpoint of security. A tracking system for radioactive material transport is being developed for use in Japan. The objective of this system is, in the rare event of an accident, for communication capabilities to share specific information among relevant organizations, the transporter, and so on

Application of the transport system concept to the transport of LSA waste

International Nuclear Information System (INIS)

Lombard, J.; Appleton, P.; Libon, H.; Sannen, H.

1994-01-01

The aim of this presentation is to illustrate using two examples how a particular special arrangement can be envisaged for the transport of a well defined category of waste according to the ''Transport System Concept''. (authors)

Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay Coastal System

Science.gov (United States)

McGann, Mary; Erikson, Li H.; Wan, Elmira; Powell, Charles; Maddocks, Rosalie F.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

Although conventional sediment parameters (mean grain size, sorting, and skewness) and provenance have typically been used to infer sediment transport pathways, most freshwater, brackish, and marine environments are also characterized by abundant sediment constituents of biological, and possibly anthropogenic and volcanic, origin that can provide additional insight into local sedimentary processes. The biota will be spatially distributed according to its response to environmental parameters such as water temperature, salinity, dissolved oxygen, organic carbon content, grain size, and intensity of currents and tidal flow, whereas the presence of anthropogenic and volcanic constituents will reflect proximity to source areas and whether they are fluvially- or aerially-transported. Because each of these constituents have a unique environmental signature, they are a more precise proxy for that source area than the conventional sedimentary process indicators. This San Francisco Bay Coastal System study demonstrates that by applying a multi-proxy approach, the primary sites of sediment transport can be identified. Many of these sites are far from where the constituents originated, showing that sediment transport is widespread in the region. Although not often used, identifying and interpreting the distribution of naturally-occurring and allochthonous biologic, anthropogenic, and volcanic sediment constituents is a powerful tool to aid in the investigation of sediment transport pathways in other coastal systems.

Engineering Development of Ceramic Membrane Reactor System for Converting Natural Gas to Hydrogen and Synthesis Gas for Liquid Transportation Fuels

Energy Technology Data Exchange (ETDEWEB)

Air Products and Chemicals

2008-09-30

An Air Products-led team successfully developed ITM Syngas technology from the concept stage to a stage where a small-scale engineering prototype was about to be built. This technology produces syngas, a gas containing carbon monoxide and hydrogen, by reacting feed gas, primarily methane and steam, with oxygen that is supplied through an ion transport membrane. An ion transport membrane operates at high temperature and oxygen ions are transported through the dense membrane's crystal lattice when an oxygen partial pressure driving force is applied. This development effort solved many significant technical challenges and successfully scaled-up key aspects of the technology to prototype scale. Throughout the project life, the technology showed significant economic benefits over conventional technologies. While there are still on-going technical challenges to overcome, the progress made under the DOE-funded development project proved that the technology was viable and continued development post the DOE agreement would be warranted.

Biking and Walking: The Position of Non-Motorised Transport Modes in Transport Systems

NARCIS (Netherlands)

Rietveld, Piet

2001-01-01

Long run developments such as income growth and urban sprawl lead one to expect a continuous decline of thecontribution of non-motorised transport modes to the performance of transport systems. In terms of the total number of trips, non-motorised transport modes have retained high shares, however.

Tailoring the microstructure of porous MgO supports for asymmetric oxygen separation membranes: Optimization of thermoplastic feedstock systems

DEFF Research Database (Denmark)

Kothanda Ramachandran, Dhavanesan; Clemens, F.; Glasscock, Julie

2014-01-01

Porous magnesium oxide (MgO) structures were prepared by thermoplastic processing for use as supports in asymmetric thin film oxygen transport membranes (OTMs). The open porosity, pore size distribution, and resulting gas permeability of the MgO structures were measured for different feedstock...

A Bovine Hemoglobin-Based Oxygen Carrier as Pump Prime for Cardiopulmonary Bypass: Reduced Systemic Lactic Acidosis and Improved Cerebral Oxygen Metabolism During Low-flow in a Porcine Model

Science.gov (United States)

2010-11-10

1 A bovine hemoglobin-based oxygen carrier as pump prime for cardiopulmonary bypass: reduced systemic lactic acidosis and improved cerebral...2010 2. REPORT TYPE Final Report 3. DATES COVERED (From - To) June 2007 - November 2010 4. TITLE AND SUBTITLE A bovine hemoglobin-based oxygen...carrier as pump prime for cardiopulmonary bypass: reduced systemic lactic acidosis and improved cerebral oxygen metabolism during low-flow in a

The transnational territorial transport system of the Baltic Region

Directory of Open Access Journals (Sweden)

Gumenyuk Ivan

2012-03-01

Full Text Available In this paper we focus on the structure and territorial borders of the Baltic Sea region, and examine the key structural elements of the transnational territorial transport system. In this respect, we clarify some terms used in transport geography. For the first time the transport system gets territorially localized, which allows for a broad range of new studies of transnational transportation in the Baltic Sea area. We also identify the main principles of development and operation of international territorial transport systems and present them taking the Baltic Sea region as an example. Our findings, we hope, will have a great practical application for researchers of transport geography, especially those studying international logistics.

Traffic Route Modelling and Assignment with Intelligent Transport System

Directory of Open Access Journals (Sweden)

Kunicina Nadezhda

2014-12-01

Full Text Available The development of signal transmitting environment for multimodal traffic control will enhance the integration of emergency and specialized transport routing tools in usual traffic control paradigms - it is one of the opportunities offered by modern intelligent traffic control systems. The improvement of effective electric power use in public transport system is an advantage of Intelligent Transport System (ITS. The research is connected with the improvement of on-line traffic control and adaptation of special traffic lighting alternatives by ITS. The assignment of the nearest appropriate transport will be done by passenger request, but unlike information system, the transport planning is done on demand. The task can be solved with the help of modern technical methods and equipment, as well as by applying control paradigms of the distributed systems. The problem is solved with the help of calculations hyper-graph and scheduling theory. The goal of the research is to develop methods, which support scheduling of the emergency transport, using high performance computing.

Self-Organized Transport System

Science.gov (United States)

2009-09-28

This report presents the findings of the simulation model for a self-organized transport system where traffic lights communicate with neighboring traffic lights and make decisions locally to adapt to traffic conditions in real time. The model is insp...

Non-rocket Earth-Moon transport system

Science.gov (United States)

Bolonkin, Alexander

2003-06-01

This paper proposes a new transportation system for travel between Earth and Moon. This transportation system uses mechanical energy transfer and requires only minimal energy, using an engine located on Earth. A cable directly connects a pole of the Earth through a drive station to the lunar surface_ The equation for an optimal equal stress cable for complex gravitational field of Earth-Moon has been derived that allows significantly lower cable masses. The required strength could be provided by cables constructed of carbon nanotubes or carbon whiskers. Some of the constraints on such a system are discussed.

An Agent-Based Approach for a Smart Transport System

Directory of Open Access Journals (Sweden)

Cristian PEÑARANDA

2016-11-01

Full Text Available This paper presents a proposal for a Smart Transport System which is an application that facilitates the interconnection between people (citizens, tourists and transport providers (Bus, metro, trains, trams, defining the services that everyone can request or offer. The system has been defined as a virtual organization where agents (representing actors of the transport system can enter or leave into the system consuming or offering services. Due to the fact that modern urban public transport is increasingly an important service used by citizens in current cities, the proposed system will improve the use of resources while also ensuring time flexible mobility solutions for citizens.

Oxygen dynamics around buried lesser sandeels Ammodytes tobianus (Linnaeus 1785): mode of ventilation and oxygen requirements

DEFF Research Database (Denmark)

Behrens, Jane W; Stahl, Henrik J; Steffensen, John F

2007-01-01

The oxygen environment around buried sandeels (Ammodytes tobianus) was monitored by planar optodes. The oxygen penetration depth at the sediment interface was only a few mm. Thus fish, typically buried at 1-4 cm depth, were generally in anoxic sediment. However, they induced an advective transport...... down along the body, referred to as ;plume ventilation'. Yet, within approximately 30 min the oxic plume was replenished by oxygen-depleted water from the gills. The potential for cutaneous respiration by the buried fish was thus of no quantitative importance. Calculations derived by three independent...... methods (each with N=3) revealed that the oxygen uptake of sandeel buried for 6-7 h was 40-50% of previous estimates on resting respirometry of non-buried fish, indicating lower O(2) requirements during burial on a diurnal timescale. Buried fish exposed to decreasing oxygen tensions gradually approached...

Intermodal transport as an integral part of logistics system

Directory of Open Access Journals (Sweden)

Agnieszka Bitkowska

2016-06-01

Full Text Available The experience of companies that are successful in the carriage of goods prove that intermodal transport is now a major factor in determining the success of logistics system. A modern approach to the transport is based on intermodal transport. The article is based on the method of external observation. It presents the essence of intermodal transport and its benefits. It specifies transportation as an integral part of logistics system.

A novel ion transport membrane reactor for fundamental investigations of oxygen permeation and oxy-combustion under reactive flow conditions

KAUST Repository

Kirchen, Patrick

2013-01-01

Ion transport membrane (ITM) reactors present an attractive technology for combined air separation and fuel conversion in applications such as syngas production, oxidative coupling or oxy-combustion, with the promise of lower capital and operating costs, as well higher product selectivities than traditional technologies. The oxygen permeation rate through a given ITM is defined by the membrane temperature and oxygen chemical potential difference across it. Both of these parameters can be strongly influenced by thermochemical reactions occurring in the vicinity of the membrane, though in the literature they are often characterized in terms of the well mixed product stream at the reactor exit. This work presents the development of a novel ITM reactor for the fundamental investigation of the coupling between fuel conversion and oxygen permeation under well defined fluid dynamic and thermodynamic conditions, including provisions for spatially resolved, in-situ investigations. A planar, finite gap stagnation flow reactor with optical and probe access to the reaction zone is used to facilitate in-situ measurements and cross-validation with detailed numerical simulations. Using this novel reactor, baseline measurements are presented to elucidate the impact of the sweep gas fuel (CH4) fraction on the oxygen permeation and fuel conversion. In addition, the difference between well-mixed gas compositions measured at the reactor outlet and those measured in the vicinity of the membrane surface are discussed, demonstrating the unique utility of the reactor. © 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Liquid-core nanocellulose-shell capsules with tunable oxygen permeability.

Science.gov (United States)

Svagan, A J; Bender Koch, C; Hedenqvist, M S; Nilsson, F; Glasser, G; Baluschev, S; Andersen, M L

2016-01-20

Encapsulation of oxygen sensitive components is important in several areas, including those in the food and pharmaceutical sectors, in order to improve shelf-life (oxidation resistance). Neat nanocellulose films demonstrate outstanding oxygen barrier properties, and thus nanocellulose-based capsules are interesting from the perspective of enhanced protection from oxygen. Herein, two types of nanocellulose-based capsules with liquid hexadecane cores were successfully prepared; a primary nanocellulose polyurea-urethane capsule (diameter: 1.66 μm) and a bigger aggregate capsule (diameter: 8.3 μm) containing several primary capsules in a nanocellulose matrix. To quantify oxygen permeation through the capsule walls, an oxygen-sensitive spin probe was dissolved within the liquid hexadecane core, allowing non-invasive measurements (spin-probe oximetry, electron spin resonance, ESR) of the oxygen concentration within the core. It was observed that the oxygen uptake rate was significantly reduced for both capsule types compared to a neat hexadecane solution containing the spin-probe, i.e. the slope of the non-steady state part of the ESR-curve was approximately one-third and one-ninth for the primary nanocellulose capsule and aggregated capsule, respectively, compared to that for the hexadecane sample. The transport of oxygen was modeled mathematically and by fitting to the experimental data, the oxygen diffusion coefficients of the capsule wall was determined. These values were, however, lower than expected and one plausible reason for this was that the ESR-technique underestimate the true oxygen uptake rate in the present systems at non-steady conditions, when the overall diffusion of oxygen was very slow. Copyright © 2015 Elsevier Ltd. All rights reserved.

Transport phenomena in particulate systems

CERN Document Server

Freire, José Teixeira; Ferreira, Maria do Carmo

2012-01-01

This volume spans 10 chapters covering different aspects of transport phenomena including fixed and fluidized systems, spouted beds, electrochemical and wastewater treatment reactors. This e-book will be valuable for students, engineers and researchers aiming to keep updated on the latest developments on particulate systems.

Guide to federal intelligent transportation system (ITS) research.

Science.gov (United States)

2013-01-01

The U.S. Department of Transportations (USDOT) Intelligent Transportation System (ITS) Program aims to bring connectivity to transportation through the use of advanced wireless technologies powerful technologies that enable transformative chan...

Decarbonizing Sweden’s energy and transportation system by 2050

DEFF Research Database (Denmark)

Bramstoft, Rasmus; Skytte, Klaus

2017-01-01

Decarbonizing Sweden’s transportation sector is necessary to realize its long-term vision of eliminating net greenhouse gas (GHG) emissions from the energy system by 2050. Within this context, this study develops two scenarios for the transportation sector: one with high electrification (EVS......) and the other with high biofuel and biomethane utilization (BIOS). The energy system model STREAM is utilized to compute the socioeconomic system cost and simulate an integrated transportation, electricity, gas, fuel refinery, and heat system. The results show that electrifying a high share of Sweden’s road...... transportation yields the least systems cost. However, in the least-cost scenario (EVS), bioenergy resources account for 57% of the final energy use in the transportation sector. Further, a sensitivity analysis shows that the costs of different types of cars are the most sensitive parameters in the comparative...

Localized increase of tissue oxygen tension by magnetic targeted drug delivery

Science.gov (United States)

Liong, Celine; Ortiz, Daniel; Ao-ieong, Eilleen; Navati, Mahantesh S.; Friedman, Joel M.; Cabrales, Pedro

2014-07-01

Hypoxia is the major hindrance to successful radiation therapy of tumors. Attempts to increase the oxygen (O2) tension (PO2) of tissue by delivering more O2 have been clinically disappointing, largely due to the way O2 is transported and released by the hemoglobin (Hb) within the red blood cells (RBCs). Systemic manipulation of O2 transport increases vascular resistance due to metabolic autoregulation of blood flow to prevent over oxygenation. This study investigates a new technology to increase O2 delivery to a target tissue by decreasing the Hb-O2 affinity of the blood circulating within the targeted tissue. As the Hb-O2 affinity decreases, the tissue PO2 to satisfy tissue O2 metabolic needs increases without increasing O2 delivery or extraction. Paramagnetic nanoparticles (PMNPs), synthetized using gadolinium oxide, were coated with the cell permeable Hb allosteric effector L35 (3,5-trichlorophenylureido-phenoxy-methylpropionic acid). L35 decreases Hb affinity for O2 and favors the release of O2. The L35-coated PMNPs (L35-PMNPs) were intravenously infused (10 mg kg-1) to hamsters instrumented with the dorsal window chamber model. A magnetic field of 3 mT was applied to localize the effects of the L35-PMNPs to the window chamber. Systemic O2 transport characteristics and microvascular tissue oxygenation were measured after administration of L35-PMNPs with and without magnetic field. The tissue PO2 in untreated control animals was 25.2 mmHg. L35-PMNPs without magnetic field decreased tissue PO2 to 23.4 mmHg, increased blood pressure, and reduced blood flow, largely due to systemic modification of Hb-O2 affinity. L35-PMNPs with magnetic field increased tissue PO2 to 27.9 mmHg, without systemic or microhemodynamic changes. These results indicate that localized modification of Hb-O2 affinity can increase PO2 of target tissue without affecting systemic O2 delivery or triggering O2 autoregulation mechanisms. This technology can be used to treat local hypoxia and to

DISSOLVED OXYGEN REDUCTION IN THE DIII-D NEUTRAL BEAM ION SOURCE COOLING SYSTEM

International Nuclear Information System (INIS)

YIP, H.; BUSATH, J.; HARRISON, S.

2004-03-01

OAK-B135 Neutral beam ion sources (NBIS) are critical components for the neutral beam injection system supporting the DIII-D tokamak. The NBIS must be cooled with 3028 (ell)/m (800 gpm) of de-ionized and de-oxygenated water to protect the sources from overheating and failure. These ions sources are currently irreplaceable. Since the water cooled molybdenum components will oxidize in water almost instantaneously in the presence of dissolved oxygen (DO), de-oxygenation is extremely important in the NBIS water system. Under normal beam operation the DO level is kept below 5 ppb. However, during weeknights and weekends when neutral beam is not in operation, the average DO level is maintained below 10 ppb by periodic circulation with a 74.6 kW (100 hp) pump, which consumes significant power. Experimental data indicated evidence of continuous oxygen diffusion through non-metallic hoses in the proximity of the NBIS. Because of the intermittent flow of the cooling water, the DO concentration at the ion source(s) could be even higher than measured downstream, and hence the concern of significant localized oxidation/corrosion. A new 3.73 kW (5 hp) auxiliary system, installed in the summer of 2003, is designed to significantly reduce the peak and the time-average DO levels in the water system and to consume only a fraction of the power

Analysis of the energy efficiency of the transport system in Algeria; Analyse de l'efficacite energetique du systeme de transport en Algerie

Energy Technology Data Exchange (ETDEWEB)

Hamdani, Sid Ahmed

2010-09-15

The objective of this communication is analyze the energy efficiency of the transport system in Algeria and to show the areas of possible rationalization in this sector. Our approach is to analyze the existing configuration of the sector and its impact on energy consumption, by developing a sectional model Bottom Up, where the transport park has been modified by the means used. We have shown that the potential to improve the transport system energy efficiency is important and have recommended some options aimed at the sector organisation and aimed at increasing the relative part of transport systems to make it more energy efficient. [French] L'objectif de cette communication est d'analyser l'efficacite energetique du systeme de transport algerien et de montrer les gisements de rationalisation possibles dans ce secteur. Notre approche consiste a analyser la configuration existante du secteur et son impact sur la consommation d'energie, en elaborant un modele sectoriel Bottom Up, ou le parc de transport a ete desagrege par moyen utilise. Nous avons montre que le potentiel d'amelioration de la performance energetique du systeme de transport est important et avons recommande quelques options ciblant l'organisation du secteur et visant a augmenter la part relative de moyens de transport plus efficace energetiquement.

Natural hazard impacts on transport systems: analyzing the data base of transport accidents in Russia

Science.gov (United States)

Petrova, Elena

2015-04-01

We consider a transport accident as any accident that occurs during transportation of people and goods. It comprises of accidents involving air, road, rail, water, and pipeline transport. With over 1.2 million people killed each year, road accidents are one of the world's leading causes of death; another 20-50 million people are injured each year on the world's roads while walking, cycling, or driving. Transport accidents of other types including air, rail, and water transport accidents are not as numerous as road crashes, but the relative risk of each accident is much higher because of the higher number of people killed and injured per accident. Pipeline ruptures cause large damages to the environment. That is why safety and security are of primary concern for any transport system. The transport system of the Russian Federation (RF) is one of the most extensive in the world. It includes 1,283,000 km of public roads, more than 600,000 km of airlines, more than 200,000 km of gas, oil, and product pipelines, 115,000 km of inland waterways, and 87,000 km of railways. The transport system, especially the transport infrastructure of the country is exposed to impacts of various natural hazards and weather extremes such as heavy rains, snowfalls, snowdrifts, floods, earthquakes, volcanic eruptions, landslides, snow avalanches, debris flows, rock falls, fog or icing roads, and other natural factors that additionally trigger many accidents. In June 2014, the Ministry of Transport of the RF has compiled a new version of the Transport Strategy of the RF up to 2030. Among of the key pillars of the Strategy are to increase the safety of the transport system and to reduce negative environmental impacts. Using the data base of technological accidents that was created by the author, the study investigates temporal variations and regional differences of the transport accidents' risk within the Russian federal regions and a contribution of natural factors to occurrences of different

Shenzhen Comprehensive Transport System Planning:An Exploration of Sustainable Urban Transport Development on Condition of Limited Resources

Institute of Scientific and Technical Information of China (English)

2010-01-01

With "integration" as the direction,Shenzhen Comprehensive Transport Planning integrates the plan,construction and management of all kinds of transport mode in the transport system,and integrates the transport with the social,economic and environment development.The planning specifies the strategic targets,key indicators,development strategies as well as major policies of the comprehensive transport system,which explores an alternative way for the sustainable urban transport development under the condition of limited resources in Shenzhen.

Wireless Communications in Smart Rail Transportation Systems

Directory of Open Access Journals (Sweden)

César Briso-Rodríguez

2017-01-01

Full Text Available Railway, subway, airplane, and other transportation systems have drawn an increasing interest on the use of wireless communications for critical and noncritical services to improve performance, reliability, and passengers experience. Smart transportation systems require the use of critical communications for operation and control, and wideband services can be provided using noncritical communications. High speed train (HST is one of the best test cases for the analysis of communication links and specification of the general requirements for train control and supervision, passenger communications, and onboard and infrastructure wireless sensors. In this paper, we analyze in detail critical and noncritical networks mainly using the HST as a test case. First, the different types of links for smart rail transportation are described, specifying the main requirements of the transportation systems, communications, and their applications for different services. Then, we propose a network architecture and requirements of the communication technologies for critical and noncritical data. Finally, an analysis is made for the future technologies, including the fifth-generation (5G communications, millimeter wave (mmWave, terahertz (THz, and satellites for critical and high-capacity communications in transportation.

Oxygen control systems and impurity purification in LBE: Learning from DEMETRA project

Energy Technology Data Exchange (ETDEWEB)

Brissonneau, L., E-mail: laurent.brissonneau@cea.fr [CEA/DEN, Cadarache, DTN/STPA/LIPC, F-13108 Saint-Paul-lez-Durance (France); Beauchamp, F.; Morier, O. [CEA/DEN, Cadarache, DTN/STPA/LIPC, F-13108 Saint-Paul-lez-Durance (France); Schroer, C.; Konys, J. [Karlsruher Institut fuer Technologie (KIT), Institut fuer Materialforschung III, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Kobzova, A.; Di Gabriele, F. [NRI, UJV Husinec-Rez 130, Rez 25068 (Czech Republic); Courouau, J.-L. [CEA/DEN, Saclay, DPC/SCCME/LECNA, F-919191 Gif-sur-Yvette (France)

2011-08-31

Operating a system using Lead-Bismuth Eutectic (LBE) requires a control of the dissolved oxygen concentration to avoid corrosion of structural materials and oxide build-up in the coolant. Reliable devices are therefore needed to monitor and adjust the oxygen concentration and to remove impurities during operation. In this article, we describe the learning gained from experiments run in the framework of the DEMETRA project (IP-EUROTRANS 6th FP contract) on the oxygen supply in LBE and on impurity filtration and management in different European facilities. An oxygen control device should supply oxygen in LBE at sufficient rate to compensate loss by surface oxidation, otherwise local dissolution of oxide layers might lead to the loss of steel protection against dissolution. Oxygen can be supplied by gas phase H{sub 2}O or O{sub 2}, or by solid phase, PbO dissolution. Each of these systems has substantial advantages and drawbacks. Considerations are given on devices for large scale facilities. The management of impurities (lead oxides and corrosion products) is also a crucial issue as their presence in the liquid phase or in the aerosols is likely to impair the facility, instrumentation and mechanical devices. To avoid impurity build-up on the long-term, purification of LBE is required to keep the impurity inventory low by trapping oxide and metallic impurities in specific filter units. On the basis of impurities characterisation and experimental results gained through filtration tests in different loops, this paper gives a description of the state-of-art knowledge of LBE purification with different filter media. It is now understood that the nature and behaviour of impurities formed in LBE will change according to the operating modes as well as the method to propose to remove impurities. This experience can be used to validate the basis filtration process, define the operating procedures and evaluate perspectives for the design of purification units for long

Transport of oxygen ions in Er doped La2Mo2O9 oxide ion conductors: Correlation with microscopic length scales

Science.gov (United States)

Paul, T.; Ghosh, A.

2018-01-01

We report oxygen ion transport in La2-xErxMo2O9 (0.05 ≤ x ≤ 0.25) oxide ion conductors. We have measured conductivity and dielectric spectra at different temperatures in a wide frequency range. The mean square displacement and spatial extent of non-random sub-diffusive regions are estimated from the conductivity spectra and dielectric spectra, respectively, using linear response theory. The composition dependence of the conductivity is observed to be similar to that of the spatial extent of non-random sub-diffusive regions. The behavior of the composition dependence of the mean square displacement of oxygen ions is opposite to that of the conductivity. The attempt frequency estimated from the analysis of the electric modulus agrees well with that obtained from the Raman spectra analysis. The full Rietveld refinement of X-ray diffraction data of the samples is performed to estimate the distance between different oxygen lattice sites. The results obtained from such analysis confirm the ion hopping within the spatial extent of non-random sub-diffusive regions.

Temperature effects on hemocyanin oxygen binding in an antarctic cephalopod.

Science.gov (United States)

Zielinski, S; Sartoris, F J; Pörtner, H O

2001-02-01

The functional relevance of oxygen transport by hemocyanin of the Antarctic octopod Megaleledone senoi and of the eurythermal cuttlefish Sepia officinalis was analyzed by continuous and simultaneous recordings of changes in pH and hemocyanin oxygen saturation in whole blood at various temperatures. These data were compared to literature data on other temperate and cold-water cephalopods (octopods and giant squid). In S. officinalis, the oxygen affinity of hemocyanin changed at deltaP50/degrees C = 0.12 kPa (pH 7.4) with increasing temperatures; this is similar to observations in temperate octopods. In M. senoi, thermal sensitivity was much smaller (delta log P50/delta pH) increased with increasing temperature in both the cuttlefish and the Antarctic octopod. At low PO2 (1.0 kPa) and pH (7.2), the presence of a large venous oxygen reserve (43% saturation) insensitive to pH reflects reduced pH sensitivity and high oxygen affinity in M. senoi hemocyanin at 0 degrees C. In S. officinalis, this reserve was 19% at pH 7.4, 20 degrees C, and 1.7 kPa O2, a level still higher than in squid. These findings suggest that the lower metabolic rate of octopods and cuttlefish compared to squid is reflected in less pH-dependent oxygen transport. Results of the hemocyanin analysis for the Antarctic octopod were similar to those reported for Vampyroteuthis--an extremely high oxygen affinity supporting a very low metabolic rate. In contrast to findings in cold-adapted giant squid, the minimized thermal sensitivity of oxygen transport in Antarctic octopods will reduce metabolic scope and thereby contribute to their stenothermality.

Sintering boat transport system for the SAF line

International Nuclear Information System (INIS)

Egli, W.; Bogart, R.L.

1983-10-01

The Secure Automated Fabrication (SAF) line will be a remotely operated process for the manufacture of breeder reactor fuel pins. The sintering boat transport system will service the pellet operations. Since the Boat Transport System will be the major link between several subsystem operations, reliability and ease of maintenance are prime requirements for the design. A prototypic version of the Boat Transport System was designed, built and tested to verify the operability of the selected approach. Extensive testing provided valuable input to the final design and substantiated the soundness of the concept

A demonstration of expert systems applications in transportation engineering : volume I, transportation engineers and expert systems.

Science.gov (United States)

1987-01-01

Expert systems, a branch of artificial-intelligence studies, is introduced with a view to its relevance in transportation engineering. Knowledge engineering, the process of building expert systems or transferring knowledge from human experts to compu...

Oxygen reduction kinetics and transport properties of (Ba,Sr)(Co,Fe)O3-δ solid oxide fuel cell cathode materials

International Nuclear Information System (INIS)

Wang, Lei; Merkle, Rotraut; Baumann, Frank S.; Maier, Joachim; Fleig, Juergen

2007-01-01

Full text: The oxygen reduction at the surface of cathode materials is crucial for the performance of solid oxide fuel cells (SOFC), but a detailed understanding of the mechanism is not available yet. (Ba x Sr 1-x )(Co 1-y Fe y )O 3-δ shows strongly improved oxygen reduction rates compared to previously applied perovskite cathode materials. In this work, surface rate constants as well as bulk transport properties are studied. (Ba x Sr 1-x )(Co 1-y Fe y )O 3-δ with 0≤x≤0.5, 0.2≤y≤1 was synthesized by the Pechini method. Oxygen stoichoimetry was obtained from thermo-gravimetric analysis, confirming that Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ has an exceptionally low oxygen content which is generally smaller than 2.5. Dense thin films were grown by pulsed laser deposition (PLD) and patterned into circular microelectrodes by photolithography. The surface resistance R s , which dominate the overall electrode resistance, were measured by impedance spectroscopy on individual microelectrodes at different T, pO 2 and applied electrical bias. PLD technique greatly helps to study the oxygen reduction kinetics since only measurements on dense thin films allow to record absolute R s values without interference from morphology effects. These R s values were found to be much lower than those for (La,Sr)(Co,Fe)O 3-δ . The variation of the surface reaction rates with A-site and B-site composition was studied and correlations with bulk materials properties such as oxygen nonstoichiometry, ionic mobility or oxidation enthalpy were examined. Plausible reaction mechanisms as well as possible reasons for the high absolute surface reaction rates will be discussed

Driverless operation for public passenger transport systems

Energy Technology Data Exchange (ETDEWEB)

Kehl, R. [Siemens AG, Erlangen (Germany). Bereich Verkehrstechnik

2001-07-01

The author presents the automation of new and existing lines as a possible solution to the twin problems of the growing need for public transport and the threat of collapse facing many public transport systems in the big conurbations as they wrestle against overloading. It emerges that automatic, driverless operation is a suitable approach to making systems more flexible and more attractive. Automation can increase the capacities of existing systems significantly and thus help them gain more passengers. (orig.)

Operating control techniques for maglev transport systems

Energy Technology Data Exchange (ETDEWEB)

Kraft, K H; Schnieder, E

1984-06-01

The technical and operational possibilities of magnetic levitation transport systems can only be fully exploited by introducing 'intelligent' control systems which ensure automatic and trouble-free train running. The solution of exacting requirements in the fields of traction dynamics, security and control as well as information gathering transmission and processing is an important prior condition in that respect. The authors report here on the present state of research and development in operating control techniques applicable to maglev transport systems.

Control systems for the dissolved oxygen concentration in condensate- and feed-water systems in nuclear power plants

International Nuclear Information System (INIS)

Mikajiri, Motohiko; Hosaka, Seiichi.

1981-01-01

Purpose: To surely prevent the generation of corrosion products and contaminations in the systems thereby decreasing the exposure dose to operators in BWR type nuclear power plants. Constitution: Dissolved oxygen concentration in condensates is measured by a dissolved oxygen concentration meter disposed to the pipeway down stream of the condensator and the measured value is sent to an injection amount control mechanism for heater drain water. The control mechanism controls the injection amount from the injection mechanism that injection heater drain water from a feed-water heater to the liquid phase in the hot wall of the condensator. Thus, heater drawin water at high dissolved oxygen is injected to the condensates in the condensator which is de-airated and reduced with dissolved oxygen concentration, to maintain the dissolved oxygen concentration at a predetermined level, whereby stable oxide films are formed to the inner surface of the pipeways to prevent the generation of corrosion products such as rusts. (Furukawa, Y.)

Decarbonizing Sweden’s energy and transportation system by 2050

Directory of Open Access Journals (Sweden)

Rasmus Bramstoft

2017-01-01

Full Text Available Decarbonizing Sweden’s transportation sector is necessary to realize its long-term vision of eliminating net greenhouse gas (GHG emissions from the energy system by 2050. Within this context, this study develops two scenarios for the transportation sector: one with high electrification (EVS and the other with high biofuel and biomethane utilization (BIOS. The energy system model STREAM is utilized to compute the socioeconomic system cost and simulate an integrated transportation, electricity, gas, fuel refinery, and heat system. The results show that electrifying a high share of Sweden’s road transportation yields the least systems cost. However, in the least-cost scenario (EVS, bioenergy resources account for 57% of the final energy use in the transportation sector. Further, a sensitivity analysis shows that the costs of different types of cars are the most sensitive parameters in the comparative analysis of the scenarios.

Controlling Oxygen Mobility in Ruddlesden–Popper Oxides

Directory of Open Access Journals (Sweden)

Dongkyu Lee

2017-03-01

Full Text Available Discovering new energy materials is a key step toward satisfying the needs for next-generation energy conversion and storage devices. Among the various types of oxides, Ruddlesden–Popper (RP oxides (A2BO4 are promising candidates for electrochemical energy devices, such as solid oxide fuel cells, owing to their attractive physicochemical properties, including the anisotropic nature of oxygen migration and controllable stoichiometry from oxygen excess to oxygen deficiency. Thus, understanding and controlling the kinetics of oxygen transport are essential for designing optimized materials to use in electrochemical energy devices. In this review, we first discuss the basic mechanisms of oxygen migration in RP oxides depending on oxygen nonstoichiometry. We then focus on the effect of changes in the defect concentration, crystallographic orientation, and strain on the oxygen migration in RP oxides. We also briefly review their thermal and chemical stability. Finally, we conclude with a perspective on potential research directions for future investigation to facilitate controlling oxygen ion migration in RP oxides.

[Design of Oxygen Saturation, Heart Rate, Respiration Rate Detection System Based on Smartphone of Android Operating System].

Science.gov (United States)

Zhu, Mingshan; Zeng, Bixin

2015-03-01

In this paper, we designed an oxygen saturation, heart rate, respiration rate monitoring system based on smartphone of android operating system, physiological signal acquired by MSP430 microcontroller and transmitted by Bluetooth module.

TRANSPORT: a computer program for designing charged particle beam transport systems

International Nuclear Information System (INIS)

Brown, K.L.; Rothacker, F.; Carey, D.C.; Iselin, C.

1977-05-01

TRANSPORT is a first- and second-order matrix multiplication computer program intended for the design of static-magnetic beam transport systems. It has been in existence in various evolutionary versions since 1963. The present version, described in the manual given, includes both first- and second-order fitting capabilities. TRANSPORT will step through the beam line, element by element, calculating the properties of the beam or other quantities, described below, where requested. Therefore one of the first elements is a specification of the phase space region occupied by the beam entering the system. Magnets and intervening spaces and other elements then follow in the sequence in which they occur in the beam line. Specifications of calculations to be done or of configurations other than normal are placed in the same sequence, at the point where their effect is to be made

Assateague Island National Seashore alternative transportation systems planning study and business plan for alternative transportation

Science.gov (United States)

2012-08-31

The purpose of this study was to (1) study the potential expansion of existing alternative transportation systems (bicycle facilities) and development of new alternative transportation systems in and around the Maryland District of Assateague Island ...

The characterisation of vapour-phase alkali metal-tellurium-oxygen species

International Nuclear Information System (INIS)

Gomme, R.A.; Ogden, J.S.; Bowsher, B.R.

1986-10-01

Detailed assessments of hypothetical severe accidents in light water reactors require the identification of the chemical forms of the radionuclides in order to determine their transport characteristics. Caesium and tellurium are important volatile fission products in accident scenarios. This report describes detailed studies to characterise the chemical species that vaporise from heated mixtures of various alkali metal-tellurium-oxygen systems. The molecular species were characterised by a combination of quadrupole mass spectrometry and matrix isolation-infrared spectroscopy undertaken in conjunction with experiments involving oxygen-18 substitution. The resulting spectra were interpreted in terms of a vapour-phase molecule with the stoichiometry M 2 TeO 3 (M = K,Rb,Cs) for M/Te molecular ratios of ∼ 2, and polymeric species for ratios < 2. This work has demonstrated the stability of caesium tellurite. The formation of this relatively low-volatility, water-soluble species could significantly modify the transport and release of caesium and tellurium. The data presented in this report should allow more comprehensive thermodynamic calculations to be undertaken that assist in the quantification of fission product behaviour during severe reactor accidents. (author)

U.S. Army Oxygen Generation System Development

Science.gov (United States)

2010-04-01

cathode. This method is used to produce breathing oxygen onboard nuclear submarines. The other electrochemical method uses a hot ceramic membrane that...This program uses a ceramic membrane supported by a nickel superalloy matrix, making the oxygen generator cells much less prone to cracking. The...challenge of this process is the same as those of fuel cells. The environment in electrochemical oxygen generators is extremely aggressive; the ceramic

Radioactive waste transportation systems analysis and program plan

International Nuclear Information System (INIS)

Shappert, L.B.; Joy, D.S.; Heiskell, M.M.

1978-03-01

The objective of the Transportation/Logistics Study is to ensure the availability of a viable system for transporting the wastes to a federal repository in 1985. In order to accomplish this objective, a systems analysis of waste transportation has been directed by ORNL to determine the problems that must be solved and to develop a program plan that identifies which problems must first be pursued. To facilitate this overall approach and to provide for short- and long-range waste management, logistics models have been developed to determine the transportation fleet requirements and costs. Results of the study are described in this report

SDDOT transportation systems management & operations program plan.

Science.gov (United States)

2016-06-01

The objective of this project is the development of a comprehensive Transportation Systems Management and : Operations (TSM&O) Program Plan for the South Dakota Department of Transportation. This plan guides : business planning and strategic decision...

Public transport traffic management systems simulation in Craiova city

Energy Technology Data Exchange (ETDEWEB)

Racila, L.

2016-07-01

Urban transport is a comprehensive and dynamic mechanism. Therefore, all the problems for improving and reorganization of the system can be examined only in the light of a systemic approach. Currently, public passenger transport is one of the most important branches of the urban development in cities and metropolis. Public passenger transport activity and all the steps taken to improve that activity are considered to be of great social importance. In the current stage of city development, one of the main tasks is to create a public passenger transportation system that is safe, affordable, economical, reliable and environmentally friendly. The important role of passenger transport in the city's economy and achieving important social services to the population, dictates the need to introduce measures in the system that are harmonious, balanced and effective. This can only be done, in the context of current development, only after the system as a whole is tested extensively through special traffic and management software. (Author)

US Department of Energy Automated Transportation Management System

International Nuclear Information System (INIS)

Portsmouth, J.H.

1994-01-01

The U.S. Department of Energy (DOE) Transportation Management Division (TMD) is responsible for managing its various programs via a diverse combination of Government-Owned/Contractor-Operated facilities. TMD is seeking to update it automation capabilities in capturing and processing DOE transportation information. TMD's Transportation Information Network (TIN) is an attempt to bring together transportation management, shipment tracking, research activities and software products in various stages of development. The TMD's Automated Transportation Management System (ATMS) proposes to assist the DOE and its contractors in performing their daily transportation management activities and to assist the DOE Environmental Management Division in its waste management responsibilities throughout the DOE complex. The ATMS system will center about the storage, handling and documentation involved in the environmental clean-up of DOE sites. Waste shipments will be moved to approved Treatment, Storage and Disposal (TSD) facilities and/or nuclear material repositories. An additional investment in shipping samples to analytical laboratories also involves packaging and documentation according to all applicable U.S. Department of Transportation (DOT) or International Air Transport Association (IATA) regulations. The most immediate goal of effectively managing DOE transportation management functions during the 1990's is an increase in automation capabilities of the DOE and its contractors. Subject-matter experts from various DOE site locations will be brought together to develop and refine these capabilities through the maximum use of computer applications. A major part of this effort will be the identification of the most economical modes of transportation and enhanced management reporting capabilities for transportation analysis. The ATMS system will also provide for increased strategic and shipment analysis during the 1990's and beyond in support of the DOE environmental mission

Influence of oxygen treatment on transport properties of PbTe:In polycrystalline films

International Nuclear Information System (INIS)

Dashevsky, Z.; Shufer, E.; Kasiyan, V.; Flitsiyan, E.; Chernyak, L.

2010-01-01

In this work, the oxygen treatment of 1 μm thick n-type PbTe:In films was studied. Two main processes induced during the thermal treatment in oxygen atmosphere were identified. The inversion of the type of electrical conductivity in PbTe:In films from n- to p-type was observed after the thermal treatment in oxygen (T a =400 deg. C). This effect is related to indium segregation at the film surface. The photoconductivity demonstrated in PbTe:In films after oxygen treatment is due to oxygen diffusion along the grain boundaries and the creation of potential relief, which separates electron-hole pairs at the boundaries under light illumination.

Metallic substrate materials for thin film oxygen transport membranes for application in a fossil power plant

Energy Technology Data Exchange (ETDEWEB)

Xing, Y.; Baumann, S.; Sebold, D.; Meulenberg, W.A.; Stoever, D. [Forschungszentrum Juelich GmbH (DE). Inst. fuer Energieforschung (IEF) - IEF-1 Materials Synthesis and Processing

2010-07-01

La{sub 0.58}Sr{sub 0.4}CO{sub 0.2}Fe{sub 0.8}O{sub 3-{delta}} (LSCF58428) and Ba{sub 0.5}Sr{sub 0.5}CO{sub 0.8}Fe{sub 3-{delta}} (BSCF5582) exhibit high oxygen permeability due to their high ionic and electronic conductivity. For this reason they are under discussion for application in oxygen transport membranes (OTMs) in zero-emission power plants using oxyfuel technology. A thin film membrane which can increase the oxygen flux is beneficial and a structural substrate is required. Two types of Ni-base alloys were studied as substrate material candidates with a number of advantages, such as high strength, high temperature stability, easy joining and similar thermal expansion coefficient to the selected perovskite materials. Chemical compositions and thermal expansion coefficients of Ni-base alloys were measured in this study. LSCF58428 and BSCF5582 layers were screen printed on Ni-based alloys and co-fired at high temperature in air. The microstructure and element analysis of samples were characterized by scanning electron microscopy (SEM and EDX). A Ni-base alloy, MCrAlY, with a high Al content was the most suitable substrate material, and showed better chemical compatibility with perovskite materials at high temperature than Hastelloy X, which is a chromia-forming Ni-base alloy. A reaction occurred between Sr in the perovskite and the alumina surface layers on MCr-AlY. However, the reaction zone did not increase in thickness during medium-term annealing at 800 C in air. Hence, it is expected that this reaction will not prevent the application of MCr-AlY as a substrate material. (orig.)

Expert systems for automated maintenance of a Mars oxygen production system

Science.gov (United States)

Huang, Jen-Kuang; Ho, Ming-Tsang; Ash, Robert L.

1992-08-01

Application of expert system concepts to a breadboard Mars oxygen processor unit have been studied and tested. The research was directed toward developing the methodology required to enable autonomous operation and control of these simple chemical processors at Mars. Failure detection and isolation was the key area of concern, and schemes using forward chaining, backward chaining, knowledge-based expert systems, and rule-based expert systems were examined. Tests and simulations were conducted that investigated self-health checkout, emergency shutdown, and fault detection, in addition to normal control activities. A dynamic system model was developed using the Bond-Graph technique. The dynamic model agreed well with tests involving sudden reductions in throughput. However, nonlinear effects were observed during tests that incorporated step function increases in flow variables. Computer simulations and experiments have demonstrated the feasibility of expert systems utilizing rule-based diagnosis and decision-making algorithms.

Thermodinamic study the uranium-oxygen system within the composition range 2,61 < O/U < 2,67

International Nuclear Information System (INIS)

Caneiro, Alberto.

1983-01-01

Oxygen partial pressures (Psub(O2)) as a function of composition and temperature were studied in order to determine the thermodynamic properties of the Uranium-Oxygen (U-O) system. To measure and control Psub(O2), an electrochemical system was used, consisting of an oxygen electrochemical pump and a zirconia gauge which allowed a very accurate determination of the CO + 1/2O 2 = CO 2 reaction. In order to determine oxygen composition, a symmetrical thermogravimetric system a Cahn 1000 electrobalance was constructed and coupled to the system for controlling and measuring Psub(O2) so as to constitute an experimental set-up, which is unique in its type at the present. This facility allowed to determine the thermodynamic properties of the (U-O) system within the composition-temperature range 2,61 3 O 8 ) and of a non-stoichiometric phase (U 8 Osub(21+x)), both being separated by a narrow region of coexistence. Analytical expressions were established for the oxygen chemical potential as a function of composition and temperature, for the stable equilibrium states of the U 8 Osub(21+x) phase and for the metastable ones obtained by oxidation of U 8 Osub(21+x). (M.E.L.) [es

Investments and Operation in an Integrated Power and Transport System

DEFF Research Database (Denmark)

Juul, Nina; Boomsma, Trine Krogh

2013-01-01

This chapter analyses an integrated power and road transport system. For analysing the influences of including passenger road transport in the energy system, a road transport model is developed. Based on this model, the benefits of integration of the two systems and using electric-drive vehicles ...

Single Cell Oxygen Mapping (SCOM) by Scanning Electrochemical Microscopy Uncovers Heterogeneous Intracellular Oxygen Consumption

OpenAIRE

Santos, Carla Santana; Kowaltowski, Alicia J.; Bertotti, Mauro

2017-01-01

We developed a highly sensitive oxygen consumption scanning microscopy system using platinized platinum disc microelectrodes. The system is capable of reliably detecting single-cell respiration, responding to classical regulators of mitochondrial oxygen consumption activity as expected. Comparisons with commercial multi-cell oxygen detection systems show that the system has comparable errors (if not smaller), with the advantage of being able to monitor inter and intra-cell heterogeneity in ox...

Geographic Information Systems-Transportation ISTEA management systems server-net prototype pooled fund study: Phase B summary

Energy Technology Data Exchange (ETDEWEB)

Espinoza, J. Jr.; Dean, C.D.; Armstrong, H.M. [and others

1997-06-01

The Geographic Information System-Transportation (GIS-T) ISTEA Management Systems Server Net Prototype Pooled Fund Study represents the first national cooperative effort in the transportation industry to address the management and monitoring systems as well as the statewide and metropolitan transportation planning requirements of the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA). The Study was initiated in November 1993 through the Alliance for Transportation Research and under the leadership of the New Mexico State Highway and Transportation Department. Sandia National Laboratories, an Alliance partner, and Geographic Paradigm Computing. Inc. provided technical leadership for the project. In 1992, the Alliance for Transportation Research, the New Mexico State Highway and Transportation Department, Sandia National Laboratories, and Geographic Paradigm Computing, Inc., proposed a comprehensive research agenda for GIS-T. That program outlined a national effort to synthesize new transportation policy initiatives (e.g., management systems and Intelligent Transportation Systems) with the GIS-T server net ideas contained in the NCHRP project {open_quotes}Adaptation of GIS to Transportation{close_quotes}. After much consultation with state, federal, and private interests, a project proposal based on this agenda was prepared and resulted in this Study. The general objective of the Study was to develop GIS-T server net prototypes supporting the ISTEA requirements for transportation planning and management and monitoring systems. This objective can be further qualified to: (1) Create integrated information system architectures and design requirements encompassing transportation planning activities and data. (2) Encourage the development of functional GIS-T server net prototypes. (3) Demonstrate multiple information systems implemented in a server net environment.

Neoclassical transport in toroidal systems

International Nuclear Information System (INIS)

Wobig, H.

1992-01-01

The neoclassical theory of general toroidal equilibria is reformulated. The toroidal equilibrium of tokamaks and stellarators are described in Hamada coordinates. The relevant geometrical parameters are identified and it is shown how the reduction of Pfirsch-Schluter currents affects neoclassical transport and bootstrap effects. General flux-friction relations between thermodynamic forces and fluxes are derived. In drift-kinetic approximation the neoclassical transport coefficients are Onsager symmetric. Since a toroidal loop voltage is included, the theory is valid for all toroidal systems. (Author)

Capacity analysis of an automated kit transportation system

NARCIS (Netherlands)

Zijm, W.H.M.; Adan, I.J.B.F.; Buitenhek, R.; Houtum, van G.J.J.A.N.

2000-01-01

In this paper, we present a capacity analysis of an automated transportation system in a flexible assembly factory. The transportation system, together with the workstations, is modeled as a network of queues with multiple job classes. Due to its complex nature, the steadystate behavior of this

Control of intracellular heme levels: Heme transporters and Heme oxygenases

Science.gov (United States)

Khan, Anwar A.; Quigley, John G.

2011-01-01

Heme serves as a co-factor in proteins involved in fundamental biological processes including oxidative metabolism, oxygen storage and transport, signal transduction and drug metabolism. In addition, heme is important for systemic iron homeostasis in mammals. Heme has important regulatory roles in cell biology, yet excessive levels of intracellular heme are toxic; thus, mechanisms have evolved to control the acquisition, synthesis, catabolism and expulsion of cellular heme. Recently, a number of transporters of heme and heme synthesis intermediates have been described. Here we review aspects of heme metabolism and discuss our current understanding of heme transporters, with emphasis on the function of the cell-surface heme exporter, FLVCR. Knockdown of Flvcr in mice leads to both defective erythropoiesis and disturbed systemic iron homeostasis, underscoring the critical role of heme transporters in mammalian physiology. PMID:21238504

Nonlinear transport properties of non-ideal systems

International Nuclear Information System (INIS)

Pavlov, G A

2009-01-01

The theory of nonlinear transport is elaborated to determine the Burnett transport properties of non-ideal multi-element plasma and neutral systems. The procedure for the comparison of the phenomenological conservation equations of a continuous dense medium and the microscopic equations for dynamical variable operators is used for the definition of these properties. The Mori algorithm is developed to derive the equations of motion of dynamical value operators of a non-ideal system in the form of the generalized nonlinear Langevin equations. In consequence, the microscopic expressions of transport coefficients corresponding to second-order thermal disturbances (temperature, mass velocity, etc) have been found in the long wavelength and low frequency limits

Transportation ALARA analysis for a nuclear waste management system

International Nuclear Information System (INIS)

McNair, G. W.; Schneider, K.; Smith, R.I.; Ross, W.; Faletti, D.

1988-01-01

In planning for implementation of a safe and cost-effective transportation system, the Department of Energy (DOE) commissioned the Pacific Northwest Laboratory (PNL) to develop estimates of the radiation doses, both public and occupational, that would result from operation of a system postulated using current designs and practices. From that evaluation, PNL identified activities/operations that result in relatively high doses, proposed conceptual alternatives that would effectively reduce such exposures, and evaluated the cost-effectiveness of such alternatives. This study contains an analysis of routine operations and estimates of the public and worker radiation doses that would occur in a postulated generic reference spent fuel transportation system using both truck and rail modes. Total risks are not estimated (i.e., consideration of nonradiological or accident risks that will be the subject of future studies in the transportation systems study plan 9TSSP) are not included). The system encompasses spent fuel loading at the reactor, transportation of the fuel to and from a receiving and handling facility and unloading of the fuel at a repository. The analysis provides cost/dose trade-offs of the postulated reference system as well as selected potential alternatives to the transportation system

Simulating the reactive transport of nitrogen species in a regional irrigated agricultural groundwater system

Science.gov (United States)

Bailey, R. T.; Gates, T. K.

2011-12-01

The fate and transport of nitrogen (N) species in irrigated agricultural groundwater systems is governed by irrigation patterns, cultivation practices, aquifer-surface water exchanges, and chemical reactions such as oxidation-reduction, volatilization, and sorption, as well as the presence of dissolved oxygen (O2). We present results of applying the newly-developed numerical model RT3D-AG to a 50,400-ha regional study site within the Lower Arkansas River Valley in southeastern Colorado, where elevated concentrations of NO3 have been observed in both groundwater and surface water during the recent decade. Furthermore, NO3 has a strong influence on the fate and transport of other contaminants in the aquifer system such as selenium (Se) through inhibition of reduction of dissolved Se as well as oxidation of precipitate Se from outcropped and bedrock shale. RT3D-AG, developed by appending the multi-species reactive transport finite-difference model RT3D with modular packages that account for variably-saturated transport, the cycling of carbon (C) and N, and the fate and transport of O2 within the soil and aquifer system, simulates organic C and organic N decomposition and mineralization, oxidation-reduction reactions, and sorption. System sources/sinks consist of applied fertilizer and manure; crop uptake of ammonium (NH4) and NO3 during the growing season; mass of O2, NO3, and NH4 associated with irrigation water and canal seepage; mass of O2, NO3, and NH4 transferred to canals and the Arkansas River from the aquifer; and dead root mass and after-harvest stover mass incorporated into the soil organic matter at the end of the growing season. Chemical reactions are simulated using first-order Monod kinetics, wherein the rate of reaction is dependent on the concentration of the reactants as well as temperature and water content of the soil. Fertilizer and manure application timing and loading, mass of seasonal crop uptake, and end-of-season root mass and stover mass are

Sustainable Transportation Systems Research Group: Ongoing and Past Activities

OpenAIRE

Gkritza, Konstantina "Nadia"; Hurtado, Davis Chacon; Gkartzonikas, Christos; Ke, Yue; Losada, Lisa L

2017-01-01

This presentation describes the ongoing and past activities of the Sustainable Transportation Systems Research (STSR) group at Purdue University (https://engineering.purdue.edu/STSRG). The STSR group aims to achieve green, safe, efficient, and equitable transportation systems by studying and modeling transportation externalities, using state of the art statistical, econometric, and economic analysis tools.

LUMOS - A Sensitive and Reliable Optode System for Measuring Dissolved Oxygen in the Nanomolar Range

DEFF Research Database (Denmark)

Lehner, Philipp; Larndorfer, Christoph; Garcia-Robledo, Emilio

2015-01-01

Most commercially available optical oxygen sensors target the measuring range of 300 to 2 mu mol L-1. However these are not suitable for investigating the nanomolar range which is relevant for many important environmental situations. We therefore developed a miniaturized phase fluorimeter based...... for read out of less sensitive optical oxygen sensors based on the same or similar indicator dyes, for example for monitoring oxygen at physiological conditions. The presented sensor system exhibits lower noise, higher resolution and higher sensitivity than the electrochemical STOX sensor previously used...... measurement system called the LUMOS (Luminescence Measuring Oxygen Sensor). It consists of a readout device and specialized "sensing chemistry" that relies on commercially available components. The sensor material is based on palladium(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin embedded...

77 FR 20872 - Intelligent Transportation Systems Program Advisory Committee; Notice of Meeting

Science.gov (United States)

2012-04-06

... DEPARTMENT OF TRANSPORTATION Intelligent Transportation Systems Program Advisory Committee; Notice.... Department of Transportation. ACTION: Notice. The Intelligent Transportation Systems (ITS) Program Advisory..., development, and implementation of intelligent transportation systems. Through its sponsor, the ITS Joint...

77 FR 51845 - Intelligent Transportation Systems Program Advisory Committee; Notice of Meeting

Science.gov (United States)

2012-08-27

... DEPARTMENT OF TRANSPORTATION Intelligent Transportation Systems Program Advisory Committee; Notice.... Department of Transportation. ACTION: Notice. The Intelligent Transportation Systems (ITS) Program Advisory..., development, and implementation of intelligent transportation systems. Through its sponsor, the ITS Joint...

MRS [monitored retrievable storage] to transportation system interfaces

International Nuclear Information System (INIS)

Row, T.H.; Croff, A.G.

1987-01-01

In March 1987, the US Department of Energy presented to Congress the proposal to construct and operate a facility for the monitored retrievable storage (MRS) of spent fuel at a site on the Clinch River in the Roane County portions of Oak Ridge. In discussing the MRS to Transportation System Interfaces, the authors provide a blending of the technical and institutional issues, for they do not believe the solutions to success of this enterprise lie wholly in one area. The authors cover: early chronology of the MRS; comparison of total-system life cycle cost estimates of the authorized system and improved-performance system (i.e., the system that includes a facility for MRS); transportation costs resulting from shipping, security and cask; assumptions for dedicated rail transport from MRS to repository; and significant results from the Total System Life Cycle Cost (TSLCC) analysis of the improved performance system. (AT)

A study on an object transport system using ultrasonic wave excitation

International Nuclear Information System (INIS)

Jeong, Sang Hwa; Kim, Gwang Ho; Choi, Suk Bong; Park, Jun Ho; Cha, Kyoung Rae

2007-01-01

The development of information and telecommunication industries leads to the development of semiconductor and optical industries. In recent years, the demand of optical components is growing due to the demand of faster network. On the other hand, conventional transport systems are not adequate for transporting precision optical components and semiconductors. Because the conveyor belt can damage precision optical components with contact force and a magnetic system would destroy the inner structure of semiconductor with magnetic field, a new system for transporting optical components and semiconductors is required. One of the alternatives to the existing systems is a transport system using ultrasonic wave excitation since it can transport precision components such as semiconductors and optical components without damage. In this paper, a transport system using 2-mode ultrasonic wave excitation was developed for transporting optical components and semiconductor, and its performance was evaluated. The relationship between transporting characteristics and flexural beam shapes were evaluated

78 FR 64048 - Intelligent Transportation Systems Program Advisory Committee; Notice of Meeting

Science.gov (United States)

2013-10-25

... DEPARTMENT OF TRANSPORTATION Intelligent Transportation Systems Program Advisory Committee; Notice.... Department of Transportation. ACTION: Notice. The Intelligent Transportation Systems (ITS) Program Advisory... implementation of intelligent transportation systems. Through its sponsor, the ITS Joint Program Office (JPO...

Physical System Requirements: Transport Waste

International Nuclear Information System (INIS)

1992-04-01

The Nuclear Waste Policy Act (NWPA) of 1982 assigned to the Department of Energy (DOE) the responsibility for managing the disposal of spent nuclear fuel and high-level radioactive waste and established the Office of Civilian Radioactive Waste Management (OCRWM) for that purpose. The Secretary of Energy, in his November 1989 report to Congress (DOE/RW-0247), announced three new initiatives for the conduct of the Civilian Radioactive Waste Management (CRWM) program. One of these initiatives was to establish improved management structure and procedures. In response, OCRWM performed a management study and the Director subsequently issued the Management Systems Improvement Strategy (MSIS) on August 10, 1990, calling for a rigorous implementation of systems engineering principles with a special emphasis on functional analysis. The functional analysis approach establishes a framework for integrating the program management efforts with the technical requirements analysis into a single, unified, and consistent program. This approach recognizes that just as the facilities and equipment comprising the physical waste management system must perform certain functions, so must certain programmatic and management functions be performed within the program in order to successfully bring the physical system into being. The objective of this document is to establish the essential functions, requirements, interfaces, and system architecture for the Transport Waste mission. Based upon the Nuclear Waste Policy Act, the mission of the Waste Transportation System is to transport SNF and/or HLW from the purchaser's/producer's facilities to, and between, NWMS facilities in a manner that protects the health and safety of the public and of workers and the quality of the environment makes effective use of financial and other resources, and to the fullest extent possible uses the private sector

Urban Transportation Systems in Bogotá and Copenhagen

DEFF Research Database (Denmark)

Pineda, Andres Felipe Valderrama; Jørgensen, Ulrik

2008-01-01

In this paper we explore the socio-technical dynamics of developing new urban transport systems. Based on the analysis of empirical material from the study of the Transmilenio in Bogotá and the Metro in Copenhagen, we propose that the design, construction and operation of urban transport systems...