Academic literature on the topic 'Various pressure and temperature conditions'
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Journal articles on the topic "Various pressure and temperature conditions":
1
Phan, Thanh-Hoang, Ebrahim Kadivar, Van-Tu Nguyen, Ould el Moctar, and Warn-Gyu Park. "Thermodynamic effects on single cavitation bubble dynamics under various ambient temperature conditions." Physics of Fluids 34, no. 2 (February 2022): 023318. http://dx.doi.org/10.1063/5.0076913.
Abstract:
Thermodynamic characteristics and their effects on single cavitation bubble dynamics are important to elucidate the physical behaviors of cavitation phenomena. In this study, experimental and numerical methods were utilized to explore the thermodynamic effects on single cavitation bubble dynamics under various ambient temperature conditions. A series of experiments was performed to generate a single cavitation bubble at ambient temperatures between 20 and 80 °C using a laser-induced method and a high-speed camera to observe the dynamic behaviors of bubbles. By increasing the ambient temperature, a nonspherical bubble shape with a jet flow at the bubble rebound stage was observed. Next, the numerical simulation results in terms of the bubble radius and bubble shape were validated with the corresponding experimental data. Generally, the results exhibited reasonable agreement, particularly at the later collapse and rebound stages. Critical hydrodynamic and thermodynamic mechanisms over multiple oscillation stages at different ambient temperatures were analyzed. The bubble behaviors and their intensities were numerically quantified with respect to the bubble radius, collapsing time, internal pressure, internal temperature, and phase transition rate parameters. The results showed that the maximum bubble radius, first minimum bubble radius, and collapsing time increased with an increase in the ambient temperature. Nevertheless, the peak values of the internal pressure and internal temperature decreased with an increase in the ambient temperature. Generally, the bubble collapsed less violently at high temperatures than at low temperatures.
2
Walter, M. J., Y. Thibault, K. Wei, and R. W. Luth. "Characterizing experimental pressure and temperature conditions in multi-anvil apparatus." Canadian Journal of Physics 73, no. 5-6 (May 1, 1995): 273–86. http://dx.doi.org/10.1139/p95-039.
Abstract:
Octahedral media made of MgO–5%Cr2O3, with edge lengths of 18, 14, and 10 mm are used as pressure cells in experiments in a multi-anvil solid media apparatus at pressures of 4 to 27 GPa and temperatures to > 2700 °C. Calibrations of press-load versus sample pressure are based on room-temperature and high-temperature phase transitions, and are accurate to within ± 0.5 GPa. Calibrations of the temperature distribution were made in the central portion of the furnaces (graphite or LaCrO3) in the various sample assemblies used routinely in this laboratory. The following gradients away from the furnace midlines were observed: 18 mm: high-T straight graphite (−100 °C mm−1), high-T stepped graphite (+ 25 °C mm−1), low-T stepped graphite (−20 °C mm−1), high-T stepped LaCrO3 (−50 °C mm−1); 14 mm: high-T stepped LaCrO3 (−70 °C mm−1); 10 mm: straight LaCrO3 (−200 °C mm−1). The effect of increasing the wall thickness of the central segment of the furnace ("stepping") is to reduce the temperature gradient relative to a straight design. The relative effect of pressure on W3Re–W25Re and Pt–Pt13Rh thermocouples was measured by comparison of apparent temperatures recorded by each type in a given experiment. Corrections for the effect of pressure on thermocouple emf depend on the temperature distribution in the gasket regions surrounding the pressure cell, where pressure is reduced to ambient conditions. The temperature of this pressure seal controls the magnitude of the effect of pressure on thermocouple emf. Because this temperature will vary depending on the assembly, no universal pressure correction can be derived.
3
Lei, Fan, Yan Xue, and Donglin Liu. "Simulation of millimeter-sized microwave plasma discharge generator under various conditions." AIP Advances 12, no. 8 (August 1, 2022): 085015. http://dx.doi.org/10.1063/5.0105035.
Abstract:
A microwave plasma generator (MPG) of a sub-millimeter scale might be suitable for biomedical applications. However, there are still many unknowns regarding the MPG discharge behavior at this scale and specific conditions. A two-dimensional MPG model at the millimeter scale and its simulation and relative calculation in the COMSOL Multiphysics software are presented. A MPG filled with argon and helium is simulated, respectively. The frequency of a microwave source of about 5 GHz is considered. The number density and temperature of electrons as well as chemical composition are obtained at different power and pressure conditions. The electron density peaks slightly downstream of the crossing point, and the electron density is slightly asymmetrically in the y-plane due to the fact that the electromagnetic waves are absorbed asymmetrically. The electron temperature is relatively low everywhere, in part, due to the high operating pressure. The electron temperature peaks directly underneath the wave guide where the wave is absorbed. The electron density increases with the increase in the internal pressure and the input power of the MPG, the electron temperature decreases with the increase in the internal pressure of the MPG, but the electron temperature cannot be affected by the input power change of MPG. The amount of excited Ar+ and Ars (metastable atom) increases with the increase in the input power and pressure of MPG, but the amount of excited Ar almost remained unchanged. In addition, the amount of excited He almost remained unchanged, while the amount of excited He+, Hes (metastable atom), and He2+ increased with the increase in the input power and pressure of MPG. The simulation results of this model are thus informative for understanding the physical characteristics of millimeter-sized MPG, and it will provide a solid basis for the future development of such hardware in small plasma capsules for cancer therapy.
4
Mohammed, Suad Abdulmuttaleb, Areej Dalaf Abbas, and Laith Salem Sabry. "Effect of Operating Conditions on Reverse Osmosis (RO) Membrane Performance." Journal of Engineering 20, no. 12 (July 9, 2023): 61–70. http://dx.doi.org/10.31026/j.eng.2014.12.04.
Abstract:
The aim of this research is to study the effect of high concentrations of salts, pressure and temperature on the performance of the RO membrane with time. Four different (Na2CO3) concentrations (5000, 15000, 25000 and 35000) ppm and various pressures such as (1, 3 and 5) bars at different temperatures of the feed solution (i.e., 25, 35 and 45) ◦C were used in this work. It was found that, as the concentration of salt and feed temperatures increase, the rejection of the salt decrease. While the salt rejection of the membranes increases with increase of transmembrane pressure.
5
Zhao, Yanlin, Qiang Liu, Liming Tang, Jian Liao, Le Chang, Xiaguang Wang, Yang Li, and Sheng Ren. "Test Study of Seepage Characteristics of Coal Rock under Various Thermal, Hydraulic, and Mechanical Conditions." Machines 10, no. 11 (November 2, 2022): 1012. http://dx.doi.org/10.3390/machines10111012.
Abstract:
The seepage characteristics of rocks under conditions of multi-field activity have always been important in the field of rock mechanics. This study used the MTS815 multi-functional electro-hydraulic servo rock testing machine to conduct seepage tests on long-flame coal specimens under different confining pressures, water pressures, and temperatures. This paper presents and discusses the seepage characteristics of coal specimens under the action of thermal hydraulic mechanical multi-field combinations. Considering parameters such as volumetric strain, temperature, thermal expansion coefficient, and initial porosity, the relationships of each parameter with porosity were obtained. The test results revealed that the volumetric strain of coal specimens increased gradually with the increase of temperature. The dynamic viscosity of water decreased with the increase of temperature, which accelerated the movement and circulation of water molecules. The increase in temperature caused the volume of the coal specimen to expand, the pores in the coal specimen squeezed against each other, the pore volume decreased, and the size of the seepage channel slowly decreased, which inhibited the seepage process. Furthermore, permeability gradually decreased with the increase of temperature. This inhibited the occurrence of seepage, and the higher the confining pressure, the lower was the permeability. The porosity of coal specimens decreased with the increase in temperature, which had an inhibitory effect on the seepage behavior. The results of this study provide experimental and theoretical support for the safe mining of coal and rock in underground mines.
6
Rashid, Waleed Turki, Israa Aziz Alkadira, and Moayyed Gased Jalhoom. "Effect of Operating Conditions on Removal Heavy and Radioactive Elements by Reverse Osmosis Membrane." Al-Qadisiyah Journal for Engineering Sciences 13, no. 3 (September 30, 2020): 240–45. http://dx.doi.org/10.30772/qjes.v13i3.665.
Abstract:
The major goal of the presented study has been studying the reverse osmosis (RO) characteristics for (Ni, Fe, Pb, Ca, Cu, K, U, and Th) removal from aqueous solution. This was done by examining the impact related to temperature and pressure on the performance regarding the RO membrane in the removal of elements with time. Three temperatures (25,35 and 45 oC) and various pressures such as (2,4 and 6) bars were used in this work. It was found that, as the pressure increase, the flux permitted and rejection of elements are increased. The temperature increases the flux permitted while the rejection of elements was steady-state almost with the increase in temperature for all heavy and radioactive elements. It also shows that these a steady-state has stopped after 35 ºC and rejection start to decrease.
7
Wang, Jie, Jie Wang, and Christine Ehlig-Economides. "Effect of Predisolved Natural Gas on CO2 Solubility in Water With Various Salinities at Reservoir Conditions." Petrophysics – The SPWLA Journal of Formation Evaluation and Reservoir Description 64, no. 6 (December 1, 2023): 970–77. http://dx.doi.org/10.30632/pjv64n6-2023a11.
Abstract:
Dissolution of CO2 in saline waters is considered one of three main CO2 trapping mechanisms, along with structural/stratigraphic trapping and mineralization. CO2 can dissolve in fresh/saline water under typical reservoir pressure and temperatures. Its solubility is dependent on pressure, temperature, and salinity. CO2 solubility studies typically consider saline water or fresh water as a liquid without any predissolved gases. The reality is formation water may contain appreciable dissolved gases for all pressure and temperature conditions. An example of gas-water ratio (GWR) can be ~1 scf/stb for formation water in an oil reservoir and ~5 to 6 scf/stb for a deep saline aquifer. Therefore, it is essential to quantify the effect of brine salinity on CO2 solubility in “live” saline waters. Just as “live” oil denotes reservoir oil that contains solution gas, we define “live” brine as saline water that includes dissolved gases. Conversely, “dead” brine refers to saline water devoid of any dissolved gas content. Two sets of experiments were conducted under typical reservoir conditions. The first set of experiments evaluated the CO2 solubility in live formation water. The second set of experiments evaluated how variation in the live brine salinity affected CO2 solubility. These experiments involved 1) synthesis of the brine, 2) synthesis of natural gas mixture, 3) recombination of live formation water with a natural gas mixture and transfer into a high-pressure and high-temperature pressure-volume-temperature (PVT) visual cell, 4) CO2 addition to the PVT cell, and 5) bubblepoint pressure determination within the PVT cell. The results showed that CO2 solubility in live formation water is significantly less than that in “dead” water under reservoir conditions. In addition, the brine salinity affects CO2 solubility in live formation water by further reducing CO2 solubility with increasing live brine salinity. As the brine salinity increases, very little CO2 can be dissolved in the live brine once it reaches a certain solubility. An understanding of CO2 dissolution in live saline water is essential for future CCUS evaluation and execution.
8
Wang, Jianqiang, Yu Song, Shuaishuai Dong, Song Ding, Yukun Geng, and Xiaotong Gao. "Triaxial Experimental Study of Zinc Contaminated Red Clay under Different Temperature Conditions." Applied Sciences 12, no. 21 (October 23, 2022): 10742. http://dx.doi.org/10.3390/app122110742.
Abstract:
Temperature is one of the important factors affecting the mechanical properties of geotechnical soils, and its role in engineering construction in China cannot be underestimated. In order to study the effects of temperature and zinc contamination concentration on the mechanical properties of Guilin local red clay, a temperature-controlled triaxial shear test was conducted on Guilin red clay under three variables of temperature, zinc contamination concentration and surrounding pressure. The test findings revealed that there are significant differences in the effects of temperature, zinc contamination concentration and surrounding pressure on the mechanical properties of Guilin red clay. The stress–strain curves of the red clay at various temperatures, contamination concentrations and envelope pressures are of the strain-hardening type, and the deformation modulus showed a tendency to increase rapidly with increasing strain, then decrease rapidly, and finally, decrease slowly. With the increase of temperature, the cohesion of Zn-contaminated red clay increases, while the angle of internal friction increases and then decreases, both of which increase the shear strength of red clay. As the concentration of Zn contamination grows, the shear strength of the red clay increases, while the internal friction angle increases and then decreases, and the shear strength of the soil increases and then decreases. The shear strength of the Zn-contaminated red clay improved as the surrounding pressure increased.
9
Harfoush, M., S. A. Mirbagheri, M. Ehteshami, and S. Nejati. "Arsenic removal from drinking water using low-pressure nanofiltration under various operating conditions." Water Practice and Technology 13, no. 2 (June 1, 2018): 295–302. http://dx.doi.org/10.2166/wpt.2018.042.
Abstract:
Abstract Currently, one of the main environmental concerns is the toxicity caused by arsenic. Arsenic-polluted water can cause many human health problems including various cancerous diseases. In natural water, inorganic arsenic can be found in the forms of arsenite and arsenate, which have been found in several Iranian provinces – e.g., East Azerbaijan, Kurdistan, and the city of Bijar – in high concentrations. Modern nanofiltration (NF) technology enables a wide range of water resource pollutants to be controlled efficiently. In this study, in an attempt to enhance arsenic removal (both arsenite and arsenate) from drinking water using low pressure NF, operating conditions like arsenic concentration, the trans-membrane pressure applied, and a range of different temperatures have all been considered. The highest arsenate removal achieved was 94% with an initial concentration of 500 μg/L, at 7 bar pressure, and 28 °C. The highest arsenite removal was 90%, with an initial concentration of 100 μg/L, at 5 bar pressure, and also at 28 °C. Increasing the pressure had a positive effect on the removal of both species, however, increasing the temperature had negative impacts. It was always found that arsenate removal was better than arsenite removal.
10
Allen, Eric E., Daniel Facciotti, and Douglas H. Bartlett. "Monounsaturated but Not Polyunsaturated Fatty Acids Are Required for Growth of the Deep-Sea BacteriumPhotobacterium profundum SS9 at High Pressure and Low Temperature." Applied and Environmental Microbiology 65, no. 4 (April 1, 1999): 1710–20. http://dx.doi.org/10.1128/aem.65.4.1710-1720.1999.
Abstract:
ABSTRACT There is considerable evidence correlating the production of increased proportions of membrane unsaturated fatty acids (UFAs) with bacterial growth at low temperatures or high pressures. In order to assess the importance of UFAs to microbial growth under these conditions, the effects of conditions altering UFA levels in the psychrotolerant piezophilic deep-sea bacterium Photobacterium profundum SS9 were investigated. The fatty acids produced byP. profundum SS9 grown at various temperatures and pressures were characterized, and differences in fatty acid composition as a function of phase growth, and between inner and outer membranes, were noted. P. profundum SS9 was found to exhibit enhanced proportions of both monounsaturated (MUFAs) and polyunsaturated (PUFAs) fatty acids when grown at a decreased temperature or elevated pressure. Treatment of cells with cerulenin inhibited MUFA but not PUFA synthesis and led to a decreased growth rate and yield at low temperature and high pressure. In addition, oleic acid-auxotrophic mutants were isolated. One of these mutants, strain EA3, was deficient in the production of MUFAs and was both low-temperature sensitive and high-pressure sensitive in the absence of exogenous 18:1 fatty acid. Another mutant, strain EA2, produced little MUFA but elevated levels of the PUFA species eicosapentaenoic acid (EPA; 20:5n-3). This mutant grew slowly but was not low-temperature sensitive or high-pressure sensitive. Finally, reverse genetics was employed to construct a mutant unable to produce EPA. This mutant, strain EA10, was also not low-temperature sensitive or high-pressure sensitive. The significance of these results to the understanding of the role of UFAs in growth under low-temperature or high-pressure conditions is discussed.
Dissertations / Theses on the topic "Various pressure and temperature conditions":
1
Song, Chenlu. "Long-term observation of rock fracture permeability and structure under various pressure and temperature conditions." Doctoral thesis, Kyoto University, 2020. http://hdl.handle.net/2433/253256.
Abstract:
京都大学0048
新制・課程博士
博士(工学)
甲第22420号
工博第4681号
新制||工||1731(附属図書館)
京都大学大学院工学研究科都市社会工学専攻
(主査)教授 岸田 潔, 教授 三村 衛, 准教授 肥後 陽介
学位規則第4条第1項該当
Doctor of Philosophy (Engineering)
Kyoto University
DFAM
2
Szilágyi, Robert. "Study of partial discharge and gas breakdown phenomena at a triple junction under various pressure and temperature conditions." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPAST007.
Abstract:
Les points triples (jonction entre un gaz, un isolant solide et un conducteur), présents dans de nombreuses applications industrielles, constituent, en raison du renforcement local du champ électrique, une zone critique pour le déclenchement des décharges électriques. De plus, ces points triples peuvent être exposés à des conditions environnementales parfois sévères. Ainsi, l'objectif de cette étude était de parvenir à une meilleure compréhension des phénomènes de décharges partielles (DP) et de claquage du gaz à partir d'un point triple sous différentes conditions de pression et de température. En particulier, ont été examinées les tensions-seuil d'amorçage/d'extinction des DP (Partial Discharge Inception Voltage, PDIV/Partial Discharge Extinction Voltage, PDEV) et la tension de claquage du gaz en surface de l'isolant solide (Flashover Voltage, FOV).Dans ce contexte, un dispositif expérimental a été conçu et exploité dans une atmosphère d'azote dont la pression était comprise entre 50 mbar et pression atmosphérique pour des températures imposées variant de l'ambiante à 400 °C. Une attention particulière a été accordée à l'alumine, matériau isolant solide qui peut être utilisé dans cette plage de température. L'influence de la température sur la PDIV (et PDEV) d'une part, et la FOV d'autre part, a été caractérisée, analysée et interprétée au moyen de mesures diélectriques, d'imagerie rapide et de simulations numériques. Enfin, dans les conditions de température élevée et malgré les précautions prises, une oxydation de l'électrode haute tension a été observée dont l'influence sur la PDIV a été analyséeTriple junctions (between a gas, a solid insulator, and a conductor), which are present in numerous industrial applications, constitute a critical zone for the triggering of electrical discharges due to local reinforcement of the electric field. In addition, these triple points can be exposed to harsh environmental conditions. The aim of this study was therefore to come to a better understanding of the phenomena of partial discharge (PD) and gas breakdown from a triple junction under different pressure and temperature conditions. In particular, the Partial Discharge Inception Voltage (PDIV), the Partial Discharge Extinction Voltage (PDEV), and the Flashover Voltage (FOV) of surface breakdown of the solid insulator were examined.In this context, an experimental set-up was designed and operated in a nitrogen atmosphere ranging from 50 mbar to atmospheric pressure, for imposed temperatures varying from ambient to 400 °C. Particular attention was paid to aluminium oxide, a solid insulator material that can be used in this temperature range. The influence of temperature on PDIV (and PDEV) on the one hand, and FOV on the other, was characterised, analysed and interpreted by means of dielectric measurements, high-speed imagery and numerical simulations. Finally, under high temperature conditions and despite the precautions taken, an oxidation of the high voltage electrode was observed whose influence on the PDIV was analysed
3
Larsen, Håvard. "Behaviour of polymer muds under high pressure – high temperature conditions." Thesis, Norwegian University of Science and Technology, Department of Petroleum Engineering and Applied Geophysics, 2007. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-1534.
Abstract:
A well is classified as a HPHT (High Pressure High Temperature) well if the static bottomhole temperatures are greater than 350 °C and when the formation pressures exceed 1800 kg/m3 ECD. Mud weights as high as 2400 kg/m3 may be required to maintain a proper well control. The temperature of the drilling fluid when circulating in the well may range from 0 °C to 150 °C and it is important that the drilling fluid maintain acceptable rheological properties within the whole range. The rheological properties of the mud will strongly depend on the temperature and the pressure variations. The problems regarding HPHT wells are mostly due to ECD and cuttings transport.
In order to control and measure the viscosity for deep HPHT wells we have conducted laboratory experiments that deal with aging at different temperatures on a polymer mud, as well as pressure and temperature effects on a field mud. We have also calculated the annular pressure using Landmark Wellplan software. To calibrate the instruments, i.e. the Physica HPHT viscometer and a Fann viscometer, we used ubelohde, known to give an exact value of the viscosity of a fluid. The calibration liquid was a 2-stroke motor oil with different amounts of Exxsol-D60 added.
The aging experiments were conducted in a mixture of water and HEC that were put in three different incubators at 20 °C, 60 °C and 90 °C for 1, 3, 8, 11, 15 and 20 days. The results showed that the viscosity decreased rapidly in the solutions that were aged at the highest temperatures and that most of the decrease took place during the first day of aging.
In the experiments on real (field) mud exposed to high pressures and temperatures the Physica viscometer was used. The results showed that the pressure effects were negligible compared to the temperature effects. During the measurements we experienced that the viscosity decreased as the temperature increased and that the decrease in the viscosity was more significant from 20 to 60 °C than from 60 to 90 °C.
Based on the results obtained in the laboratory and an evaluation of fluid implication on well pressure, we were able to draw the following main conclusions:
• Laboratory experiments are very educational. To learn that reality is not straight forward to measure was enlightening.
• The viscosity is very dependant on the temperature.
• The combined effect of pressure on the viscosity of a field mud is negligible.
• The annular pressure differences calculated in Landmark Wellplan did not show any significant differences for the different well temperatures.
4
Bagdanavicius, Audrius. "Premixed combustion of alternative fuels under varying conditions of temperature and pressure." Thesis, Cardiff University, 2010. http://orca.cf.ac.uk/54231/.
Abstract:
Temperature, pressure and CO2 and H2 addition to CH4 effects on turbulent and laminar burning velocity have been found and discussed. Novel turbulent burning velocity determination methods are presented and uncertainties have been discussed. Turbulent burning velocity correlation with nondimensional numbers have been found and flames structures have been analysed.
5
Poloni, Roberta. "Heavy alkali metal-intercalated fullerenes under high pressure and high temperature conditions." Lyon 1, 2007. http://tel.archives-ouvertes.fr/docs/00/19/46/10/PDF/THESIS.pdf.
Abstract:
Dans cette thèse nous explorons le diagramme de phase des fullerènes intercalées avec des métaux alcalins lourds, Rb6C60 et Cs6C60, à très haute pression (<50 GPa) et à très haute température (de l’ambiante à 1500 K). Ce travail inclue des expériences d’absorption de rayons X, de diffraction de rayons X, de spectroscopie Raman, ainsi que des calculs DFT ab initio à haute pression. Le couplage entre expériences et calculs permet d’observer que la présence de la forte interaction ionique entre chaque molécule et les ions alcalins, empêche la polymérisation des fullerènes sous pression. Dans le cas de Cs6C60, ceci a permis d’étendre le domaine de stabilité en pression des molécules de C60 d’au moins un facteur deux par rapport aux cristaux de C60 non-intercalés. Dans le cas de Rb6C60 une transition réversible est observée à 35 GPa. Nous avons mis en évidence la déformation progressive de la molécule de fullerène sous pression dans les systèmes étudiés. La compressibilité des deux cristaux a été mesurée et calculéeIn this thesis, we explore the phase diagram of the heavy alkali metal intercalated fullerenes, Rb6C60 and Cs6C60, under high pressure (<50 GPa) and high temperature conditions (from ambient to 1500 K). The work includes a series of X-ray absorption spectroscopy, X-ray diffraction and Raman spectroscopy measurements as well as ab initio DFT calculations under pressure. By coupling both experiments and calculations, we observed that the presence of strong ionic interactions between each molecule and the alkali metal ions, prevents fullerene polymerization under pressure. In the case of Cs6C60, this allows to extend the pressure stability of the C60 molecules more than twice with respect to pristine solid C60. In the case of Rb6C60 a phase transition, is observed at 35 GPa. A pressure induced enhanced deformation of the fullerene molecule in the studied systems has been evidenced. The compressibility of the both crystals has been measured and calculated
6
Schaffer, Joseph F. "Verification and Adaptation of an Infiltration Model for Water at Various Isothermal Temperature Conditions." Digital WPI, 1999. https://digitalcommons.wpi.edu/etd-theses/1061.
Abstract:
"A series of one dimensional horizontal infiltration experiments were performed to investigate the predictive capabilities of the Kao and Hunt model. By modifying pristine laboratory apparatus, a reasonable range of soil temperatures was achieved. Experiments were run at approximately 5°C, 20°C, and 35°C. Distilled water was used as an infiltrating liquid and silica powder was used as soil. The infiltrating liquid was dispensed into the column at zero pressure head. The results of the experiments show that the model is adaptable to a range of temperature conditions by modifying terms for the liquid effects of the model, viscosity and surface tension. Experimental data and model predictions differed by 30 percent at most. Although the change in the rate of infiltration across the range of temperatures is perceivable, it is small in comparison to the effects caused by heterogeneity encountered in nature. "
7
Seto, Kelsey C. "Hydrogen production from aluminum-water reactions subject to high pressure and temperature conditions." Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/111936.
Abstract:
Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2017.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 75-77).
Aluminum fuel has become an attractive form of energy storage in recent years as it is both a highly abundant and extremely energy dense material. Research has discovered methods of treating aluminum with liquid metal, enabling the aluminum to produce large amounts of hydrogen when oxidized by liquid water. When this fuel reacts with water, it produces hydrogen, heat, and aluminum hydroxide (Al(OH) 3 ). Although this aluminum fuel has already been integrated into an effective mobile hydrogen production source for hydrogen fuel cells, the system size and weight is restricted by the amount of water that is required to react the aluminum. The less water that needs to be carried on board, the better, and the only way to decrease the amount of water that is required to produce hydrogen through aluminum-water reactions is to alter the chemistry of the reaction. This thesis investigates the possibility of manipulating the chemistry of these reactions at high pressures and temperatures to produce aluminum oxyhydroxide (AlOOH) or aluminum oxide (Al203 ), both of which are byproducts of aluminum-water reactions which consume less water than the Al(OH) 3 reaction for the amount of hydrogen produced. A MATLAB simulation was constructed to predict the favorability of each byproduct by analyzing the Gibbs free energy of the reactions as a function of pressure and temperature. This simulation revealed that A100H becomes favorable over Al(OH) 3 at 142.38°C and 387kPa and A120 3 becomes favorable over A100H at 174.21°C and 889kPa in a system with a 200ml volume in which 5g of fuel is reacted. Pressurized tests were also carried out and the experiment results showed that A1OOH was produced from these aluminum-water reactions at 181°C and 1035kPa, proving that it is possible to manipulate these reactions to improve the performance of aluminum fuel as a hydrogen source.
by Kelsey Carolyn Seto.
S.M.
8
Holmberg, Johanna. "Pressure Temperature Conditions of the Otrøy Opmhacite-Garnet Gneiss, Western Gneiss Region, Skandinavian Caledonides." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-256283.
Abstract:
Garnet-omphacite gneisses from the island of Otrøy situated in Western Gneiss Region (WGR), Norway, Scandinavian Caledonides, were examined within this study. The WGR is one of the planets most studied ultrahigh-pressure (UHP) terranes. The studied gneisses are hosts for UHP garnet peridotites and eclogites. The presence of the high pressure mineral assemblage including e.g. omphacite and phengite together with assumed remnants of pseudomorphic transition of formerly stable coesite present in omphacite and garnet, suggest formation of the Otrøy gneisses during ultrahigh pressure metamorphism (UHPM). However, geothermobarometry based on the mineral assemblage composed of garnet + clinopyroxene + phengite yielded pressure-temperature conditions of c. 880˚C and 2.2 GPa, characteristic for just high pressure metamorphism. Nevertheless, it can be concluded that the Otrøy gneisses were formed due to the deep burial of continental crust during the continent-continent collision. This study provides insights into the understanding of the deep subduction of continental crust and expands our knowledge about the complex metamorphic and tectonic evolution of the WGR and the Scandinavian Caledonides.Granat-omphacitförande gnejser från ön Otrøy i Western Gneiss Region (WGR), Norge, Skandinaviska Kaledoniderna, har undersöks i den här studien. WGR är ett av världens mest studerade område för ultrahögtryckmetamorfa bergarter. I den här typen av gnejser förekommer linser av ultrahögtrycksbergarter så som granat-peridotiter och eklogiter. I den studerade Otrøygnejsen förekommer bland annat phengit och omphacit med inneslutningar av sannolika pseudomorfer efter coesit. Detta visar på att Otrøygnejsen troligen har bildats under metamorfos vid ultrahöga tryck. Geotermobarometriundersökningen, baserat på granat + clinopyroxen + phengitsystemet, visar att tryck- och temperaturförhållandena var ca.880 ˚C och 2.2 GPa. Det innebär att gnejsen metamorfoserats inom intervallet karaktäristiskt för högtrycksmetamorfos. Likväl, kan det fastställas att Otrøygnejsen bildats till följd av en djup subduktion under kontinent-kontinentkollision. Den här studien bidrar till en ökad förståelse av processerna som påverkar den kontinentala skorpan vid djup subduktion och vidgar våra kunskaper om den komplexa metamorfa och tektoniska utvecklingen i WGR och de Skandinaviska Kaledoniderna.
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Barboza, Felipe Moreira. "STUDY OF VIBRATIONAL PROPERTIES OF THYMIDINE CRYSTAL IN EXTREME CONDITIONS OF PRESSURE AND TEMPERATURE." Universidade Federal do CearÃ, 2017. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=18956.
Abstract:
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel SuperiorThe unit of sugar and base connected by a N-β-glycosyl linkage is named a nucleoside. In the present work the nucleoside thymidine, whose molecular formula is C10N2O5H14, was studied by Raman spectroscopy, subjecting it extreme conditions of pressure and temperature, as well as X ray diffraction measurements. An auxiliary analysis of normal crystal vibration modes was performed using first principles calculations using the B3LYP functional together with the Gaussian bases 6-31G+(d) and potential energy distribution analysis (PED). These results, together with literature data and Raman spectroscopy measurements in several thymidine scattering geometries, allowed the identification of the various normal modes of crystal vibration. X-ray diffraction experiments were performed in the temperature range between 83 and 413 K. Experiments of Raman spectroscopy under extreme temperature conditions (20 to 380 K) were performed in the spectral range of 20 to 3400 cm-1. From the analysis of the results, it is possible to draw some conclusions. (i) The thymidine crystal remained stable throughout the investigated temperature range, indicating that the temperature effect is not sufficient to modify the hydrogen bonds present between the molecules in such a way as to modify the symmetry of the crystal. (ii) The material studied showed some slight changes in the vibrational spectra in the experiment performed at low temperatures, suggesting, if not a structural phase transition, at least some conformational modification of the thymidine molecules. Raman spectra of thymidine crystal were obtained for pressures up to 5.0 GPa in a diamond anvil cell. The results show the presence of anomaly in the Raman spectrum at pressures close to 3.0 GPa. This anomaly is characterized by disappearance of lattice modes, appearance of some internal modes, splitting of high wavenumbers modes, downshift of modes associated with hydrogen bonds, changes in the intensity of internal modes and discontinuities of the slopes of the wavenumbers versus pressure for several Raman modes. This set of modifications was interpreted as consequence of a phase transition undergone by thymidine close to 3.0 GPa. Further, decompression to atmospheric pressure generates the original Raman spectrum, showing that the pressure-induced phase transition undergone by thymidine crystals is reversible. A comparison with results on other nucleosides submitted to high pressure is also furnished.
Quando a pentose (glicose) e uma base nitrogenada unem-se por meio de uma ligaÃÃo N-β glicosÃdica forma-se uma molÃcula denominada de nucleosÃdeo. No presente trabalho o nucleosÃdeo timidina, cuja fÃrmula molecular à C10N2O5H14, foi estudado atravÃs de espectroscopia Raman, submetendo-o a condiÃÃes extremas de pressÃo e de temperatura, alÃm de medidas de difraÃÃo de raios X. Uma anÃlise auxiliar a respeito dos modos normais de vibraÃÃo do cristal foi realizada atravÃs de cÃlculos de primeiros princÃpios utilizando-se o funcional B3LYP em conjunto com as bases gaussianas 6-31G+(d) e anÃlise de distribuiÃÃo de energia potencial (PED). Esses resultados, juntamente com dados da literatura e medidas de espectrocopia Raman em diversas geometrias de esplalhamento na timidina permitiram uma identificaÃÃo dos vÃrios modos normais de vibraÃÃo do cristal. Os experimentos por difraÃÃo de raios X foram realizados no intervalo de temperatura entre 83 e 413 K. Experimentos de espectroscopia Raman sob condiÃÃes extremas de temperatura (20 a 380 K) foram realizados no intervalo espectral compreendido entre 20 e 3400 cm-1. Da anÃlise dos resultados, à possÃvel tirar algumas conclusÃes. (i) O cristal de timidina manteve-se estÃvel em todo o intervalo de temperatura investigado, indicando que o efeito de temperatura nÃo à suficiente para modificar as ligaÃÃes de hidrogÃnio presentes entre as molÃculas de tal forma que haja modificaÃÃo da simetria do cristal. (ii) O material estudado apresentou algumas leves mudanÃas nos espectros vibracionais no experimento realizado a baixas temperaturas, sugerindo, se nÃo uma transiÃÃo de fase estrutural, pelo menos alguma modificaÃÃo conformacional das molÃculas da timidina. Experimentos submetendo o cristal a pressÃes de atà 5 GPa foram realizados utilizando-se uma cÃlula de pressÃo a extremos de diamantes. Os resultados mostraram anomalias nos espectros Raman por volta de 3.0 GPa. Essas anomalias foram caracterizadas pelo desaparecimento de alguns modos de rede, surgimento de alguns modos internos, deslocamento para menores nÃmeros de onda de modos associados a ligaÃÃes de hidrogÃnio e descontinuidades dos coeficientes lineares de vÃrios modos nos grÃficos de nÃmero de onda em funÃÃo da pressÃo. Essa sÃrie de modificaÃÃes foram interpretadas como consequÃncia de uma transiÃÃo de fase sofrida pela timidina por volta de 3.0 GPa. AlÃm disso, a descompressÃo da amostra atà a pressÃo atmosfÃrica mostrou que a transiÃÃo de fase à reversÃvel. TambÃm fornecemos uma comparaÃÃo com resultados de outros nucleosÃdeos submetidos a altas pressÃes.
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Bamgbade, Babatunde A. "MEASUREMENTS AND MODELING OF HYDROCARBON MIXTURE FLUID PROPERTIES UNDER EXTREME TEMPERATURE AND PRESSURE CONDITIONS." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/3967.
Abstract:
Knowledge of thermodynamic fluid properties, such as density and phase behavior, is important for the design, operation, and safety of several processes including drilling, extraction, transportation, and separation that are required in the petroleum. The knowledge is even more critical at extreme temperature and pressure conditions as the search for more crude oil reserves lead to harsher conditions. Currently, there is dearth of experimental data at these conditions and as such, the predictive capability of the existing modeling tools are unproven. The objective of this research is to develop a fundamental understanding of the impact of molecular architecture on fluid phase behavior at temperatures to 523 K (250 °C) and pressures to 275 MPa (40,000 psi). These high-temperature and high-pressure (HTHP) conditions are typical of operating conditions often encountered in petroleum exploration and recovery from ultra-deep wells that are encountered in the Gulf of Mexico.
This PhD study focuses on the fluid phase behavior of a low molecular weight compound, two moderately high molecular weight compounds, three asymmetric binary mixtures of a light gas and a heavy hydrocarbon compound with varying molecular size. The compounds are selected to represent the family of saturated compounds found in typical crude oils. Furthermore, this study reports experimental data for two "dead" crude oil samples obtained from the Gulf of Mexico and their mixtures with methane from ambient to HTHP conditions. A variable-volume view cell coupled with a linear variable differential transformer is used to experimentally measure the high-pressure properties of these compounds and mixtures. The reported density data compare well to the limited available data in the literature with deviations that are less than 0.9%, which is the experimental uncertainty of the density data reported in this study.
The phase behavior and density data obtained in this study are modeled using the Peng-Robinson (PR), the volume-translated (VT) PR, and the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equations of state (EoS). The EoS pure component parameters, typically obtained from the open literature, are derived from fitting the particular EoS to, critical point, or to vapor pressure and saturated liquid density data, or to HTHP density data. For the density data reported here, the PREoS provided the worst predictions, while the VT-PREoS gives an improved performance as compared to the PREoS. However, the PC-SAFT EoS provided the best HTHP density predictions especially when using HTHP pure component parameters. The situation is however reversed in the modeling performance for the phase behavior data whereby the PC-SAFT EoS with HTHP parameters provided the worst vapor-liquid equilibria predictions. Better predictions are obtained with the PC-SAFT EoS when using parameters obtained from fit of the vapor pressure data and is comparable to the PREoS predictions. This reversal in performance is not surprising since the phase behavior data occur at moderately low pressures. The performance of the PC-SAFT EoS is extended to the experimental density data reported for the dead crude oil samples and their mixtures with methane. The PC-SAFT EoS with either set of pure component parameters yield similar predictions that are within 3% of the reported crude oil density data. However, when using the HTHP parameters, the PC-SAFT gives a good representation of the slope of experimental data, which is crucial in the calculation of second-derivative properties such has isothermal compressibility.
The PC-SAFT EoS is also employed to model the crude oil HTHP density data for both the dead crude oils and their mixtures with methane using correlations for both the Low-P parameters and the HTHP parameters. The Low-P parameters are derived from fitting the PC-SAFT EoS to pure compound vapor pressure and saturated liquid density data, while the HTHP parameters are obtained from fitting the PC-SAFT EoS to pure compound HTHP liquid density data. Interestingly, the PC-SAFT EoS with the Low-P parameters provided better HTHP density predictions that are within 1.5% of the experimental data for the dead oils than the HTHP parameters that are within 2 to 4% of the data. Density predictions for the dead oil mixtures with methane are however comparable for both sets of parameters and are within 1% on average. However, the PC-SAFT EoS with HTHP parameters clearly provided better representation of the isothermal property, a derivative property obtained from density data, within 10% while predictions with the Low-P parameters can be as high as 37%.
The successful completion of the thesis work expands the current knowledge base of fluid phase behavior at the extreme operating conditions encountered by engineers in the petroleum industries. Furthermore, the reported HTHP experimental data also provide a means to scientists and researchers for the development, improvement, and validation of equations with improved modeling performance.
Books on the topic "Various pressure and temperature conditions":
1
United States. National Aeronautics and Space Administration., ed. Droplet-turbulence interactions in sprays exposed to supercritical environmental conditions: Final report, NASA grant, #NAG8-160. [Washington, DC: National Aeronautics and Space Administration, 1993.
2
Manaa, M. Riad. Chemistry at extreme conditions. Amsterdam: Elsevier, 2005.
3
D, Hubbard Colin, and Eldik Rudi van, eds. Chemistry under extreme or non-classical conditions. New York: John Wiley, 1996.
4
United States. National Aeronautics and Space Administration., ed. SiC recession due to SiO₂ scale volatility under combustor conditions. Brook Park, Ohio: NYMA, Inc., 1997.
5
United States. National Aeronautics and Space Administration., ed. SiC recession due to SiO₂ scale volatility under combustor conditions. Brook Park, Ohio: NYMA, Inc., 1997.
6
Canada, Atomic Energy of. Chronology and Ambient Temperature/Pressure Conditions of Fluid Flow Through the Eye-Dashwa Lakes Pluton Based on the 18O/16O Ratio and Fluid Inclusions. S.l: s.n, 1985.
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Pachurin, German. Technology for studying the destruction of structural materials under different loading conditions. ru: INFRA-M Academic Publishing LLC., 2021. http://dx.doi.org/10.12737/981296.
Abstract:
The textbook is devoted to solving topical issues related to the prediction of the effect of plastic deformation on the behavior in various operating conditions of a wide class of metals and alloys. The technology developed by the author for studying the mechanical properties and the process of destruction of plastically treated metal materials under various loading conditions (static at different temperatures, cyclic in air at low, room and elevated temperatures, as well as at room temperature in the presence of a corrosive environment) is described.
Meets the requirements of the federal state educational standards of higher education of the latest generation.
Addressed to bachelors and undergraduates of higher educational institutions of full-time and part-time education in the areas of training 20.03.01 Technosphere safety" (training profile "Safety of technological processes and production"), 22.03.01 and 22.04.01 "Materials Science and Materials Technology", 22.03.02 and 22.04.02 "Metallurgy", 15.03.01 and 15.04.01 "Mechanical Engineering", 15.05.01 "Design of technological machines and complexes", 15.03.02 "Technological machines and equipment", 15.03.04 and 15.04.04 "Automation of technological processes and production", 17.05.02 "Strelkovo-pushechnoe, artillery and rocket weapons", 15.03.05 "Design and technological support of machine-building industries". It can be useful for scientific and engineering workers of enterprises of automotive, aviation, shipbuilding and other metalworking branches of mechanical engineering, laboratory workers, as well as for training specialists in materials science, metal science and metal forming."
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Technology for high pressure high temperature reservoir conditions. London: Bentham Press, 1995.
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Jacobsen, Dean, and Olivier Dangles. The high altitude environment. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198736868.003.0001.
Abstract:
Chapter 1 gives a brief overview of the climatic and terrestrial environment in which high altitude waters are embedded. This context is necessary to understand the prevailing environmental conditions in the aquatic systems. The chapter begins by defining high altitude, alpine, and mountain, and provides an overview of the distribution of the world’s main high altitude regions. The overall picture of the climatic setting is drawn, from the inevitable consequences of high altitude (low temperature, low atmospheric pressure, and high solar radiation) to the highly region-specific patterns in precipitation and wind. The various ways that highland regions are formed, their temporal evolution, and climatic changes are treated in a section on the palaeo-environmental perspective. Finally, general patterns in high altitude (alpine) vegetation zones and treelines on different continents are synthesized, as well as major soil-forming processes in the catchments surrounding aquatic systems.
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Droplet-turbulence interactions in sprays exposed to supercritical environmental conditions: Final report, NASA grant, #NAG8-160. [Washington, DC: National Aeronautics and Space Administration, 1993.
Book chapters on the topic "Various pressure and temperature conditions":
1
Schmidt, Johannes Benedikt, Jan Breitenbach, Ilia V. Roisman, and Cameron Tropea. "Interaction of Drops and Sprays with a Heated Wall." In Fluid Mechanics and Its Applications, 333–53. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-09008-0_17.
Abstract:
AbstractSpray-wall interactions take place in many technical applications such as spray cooling, combustion processes, cleaning, wetting of surfaces, coating and painting, etc. The outcome of drop impact onto hot surfaces depends on a variety of parameters like for example material and thermal properties of the liquid and wall, substrate wetting properties, surrounding conditions which determine the saturation temperature, spray impact parameters and surface temperature. The aim of the current project is to improve knowledge of the underlying physics of spray-wall interactions. As an important step towards spray impact modeling first a single drop impact onto hot substrates is considered in detail. Various regimes of single drop impact, such as thermal atomization, magic carpet breakup, nucleate boiling and thermosuperrepellency, observed at different wall temperatures, ambient pressures and impact velocities, have been investigated experimentally and modelled theoretically during the project period. The heat flux, an important parameter for spray cooling, has been modeled not only for single drop impacts but also for sprays within many regimes. The models show a good agreement with experimental data as well as data from literature.
2
Jacquemet, Nicolas, Jacques Pironon, Vincent Lagneau, and Jérémie Saint-Marc. "Well Cement Aging in Various H2S-CO2Fluids at High Pressure and High Temperature: Experiments and Modelling Well Cement Aging at High PT Conditions." In Carbon Dioxide Sequestration and Related Technologies, 421–35. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118175552.ch23.
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Daub, Dennis, Sebastian Willems, Burkard Esser, and Ali Gülhan. "Experiments on Aerothermal Supersonic Fluid-Structure Interaction." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 323–39. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-53847-7_21.
Abstract:
Abstract Mastering aerothermal fluid-structure interaction (FSI) is crucial for the efficient and reliable design of future (reusable) launch vehicles. However, capabilities in this area are still quite limited. To address this issue, a multidisciplinary experimental and numerical study of such problems was conducted within SFB TRR 40. Our work during the last funding period was focused on studying the effects of moderate and high thermal loads. This paper provides an overview of our experiments on FSI including structural dynamics and thermal effects for configurations in two different flow regimes. The first setup was designed to study the combined effects of thermal and pressure loads. We investigated a range of conditions including shock-wave/boundary-layer interaction (SWBLI) with various incident shock angles leading to, in some cases, large flow separation with high amplitude temperature dependent panel oscillations. The respective aerothermal loads were studied in detail using a rigid reference panel. The second setup allowed us to study the effects of severe heating leading to plastic deformation of the structure. We obtained severe localized heating resulting in partly plastic deformations of more than 12 times the panel thickness. Furthermore, the effects of repeated load cycles were studied.
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Werzner, Eric, Miguel A. A. Mendes, Cornelius Demuth, Dimosthenis Trimis, and Subhashis Ray. "Simulation of Fluid Flow, Heat Transfer and Particle Transport Inside Open-Cell Foam Filters for Metal Melt Filtration." In Multifunctional Ceramic Filter Systems for Metal Melt Filtration, 301–33. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-40930-1_13.
Abstract:
AbstractIn order to develop improved filters for metal melt filtration, different physical phenomena that take place during depth filtration of liquid metals need to be well understood. Due to the difficult accessibility of the process, the harsh process conditions and the randomness of the typically employed ceramic foam filters, representative experimental investigations are extremely difficult to perform and often provide only integral quantities or selective information. This chapter presents a numerical model for simulating the depth filtration of liquid metal at the pore-scale, i.e., fully resolving the complex filter geometry, which can also accurately handle the curved filter walls. In the model, the velocity and pressure distribution of the melt flow is obtained by the lattice-Boltzmann method and the temperature field is calculated using the finite volume method, while the transport and filtration of the inclusions are predicted by solving the equation of motion for particles in a Lagrangian reference frame. In order to obtain a consistent representation of the curved filter walls for both particle transport and fluid flow, the Euclidean distance field of the filter structures is employed. By comprehensive parametric studies, the sensitivity of the filtration process with respect to various geometric parameters and process conditions is investigated. Therefore, geometries of conventionally manufactured filters, acquired from 3D μCT scanning, as well as computer-generated filter structures are considered. Their performance is assessed by evaluating various effective properties, such as the viscous and inertial permeability and the filtration coefficient. The numerical predictions allow to draw conclusions with respect to the dominant physical mechanisms and are compared with those from simplified physical models, which are shown to be sufficiently accurate for the pre-screening of filters. On the basis of the detailed results, suggestions for improved filter geometries are made, depending on the considered filtration process. Further, simplified models for the prediction of the effective thermal conductivity of open-cell foams in presence and absence of radiation are presented and validated using the detailed numerical predictions.
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Grodzinsky, Ewa, and Märta Sund Levander. "Physiological and Inflammatory Activity in Various Conditions." In Understanding Fever and Body Temperature, 115–27. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-21886-7_8.
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Razdolsky, Leo. "Transient Engineering Creep of Materials Under Various Fire Conditions." In Probability Based High Temperature Engineering, 249–383. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-41909-1_5.
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Robaschik, Dieter. "Fluctuations of the Casimir Pressure at Finite Temperature." In Quantum Field Theory Under the Influence of External Conditions, 50–53. Wiesbaden: Vieweg+Teubner Verlag, 1996. http://dx.doi.org/10.1007/978-3-663-01204-7_8.
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Gillet, Ph. "Introduction to Raman Spectroscopy at Extreme Pressure and Temperature Conditions." In Microscopic Properties and Processes in Minerals, 43–69. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-011-4465-0_3.
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Hussain, Majid, and Ajanta Sachan. "Pore Pressure Response of Natural Soils Under Various Testing Conditions." In Lecture Notes in Civil Engineering, 251–63. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-4001-5_23.
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Brianskaia, I. P., V. I. Vasenev, R. A. Hajiaghayeva, and D. V. Morev. "Evaluation of Peat Stability Under Various Temperature and Moisture Conditions." In Springer Geography, 153–59. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-89602-1_19.
Conference papers on the topic "Various pressure and temperature conditions":
1
Wang, Zhengdong, Changjun Liu, Fu-Zhen Xuan, and Shan-Tung Tu. "Determination of Material Degradation at Various Environmental Conditions." In ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57570.
Abstract:
There are growing interests in materials and system degradation at various environmental conditions, especially for structures in fossil fuel power station, nuclear power plants and petrochemical industry. Several testing and simulation approaches have been developed to determine the degradation of material properties with the influence of corrosion environment. A simulation technology is introduced to investigate the effects of irradiation on mechanical properties for a degraded reactor pressure vessel steel. The degradation procedure combines the application of cold prestrain together with high temperature heat treatment. It is found from the results of Charpy impact tests for degraded material that there is an increase of ductile-brittle transition temperature and a trend to a decrease of upper shelf energy because of irradiation embrittlement. Evaluation procedures of temper embrittlement and hydrogen-embrittlement are described for reactor pressure vessel steel exposed to hydrogen environment. A regular coupon sample test is adopted to determine the material degradation of hydrogen processing reactors. Numerical analysis and experimental hydrogen charging technique are explored to simulate the process of hydrogen embrittlement. A critical parameter of hydrogen concentration is defined to evaluate the susceptibility of hydrogen induced cracking for reactor steels. A fatigue testing system is designed to obtain the degradation of fatigue strength for materials under the low oxygen steam environment. The system couples a steam chamber with an axial force-controlled fatigue testing machine. The fatigue tests are performed for a titanium alloy with tension-compression loading up to 107 cycles. Test results show that the fatigue strength is obviously influenced by the steam environment and the stress ratios.
2
Sakaguchi, Katsumi, Yuichiro Nomura, Shigeki Suzuki, and Hiroshi Kanasaki. "Applicability of the Modified Rate Approach Method Under Various Conditions Simulating Actual Plant Conditions." In ASME 2006 Pressure Vessels and Piping/ICPVT-11 Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/pvp2006-icpvt-11-93220.
Abstract:
The fatigue life in elevated temperature water is strongly affected by water chemistry, temperature and strain rate. The effects of these parameters on fatigue life reduction have been investigated experimentally. In transient condition in an actual plant, however, such parameters as temperature and strain rate are not constant. In order to evaluate fatigue damage in actual plant on the basis of experimental results under constant temperature and strain rate condition, the modified rate approach method was developed. As a part of the EFT (Environmental Fatigue Tests) project, the study was conducted in order to evaluate the applicability of the modified rate approach to the case where temperature and strain rate varied simultaneously. It was reported in the previous papers (1,2) that the accuracy of modified rate approach is about factor of 2. Various kinds of transient have to be taken into account of in actual plant fatigue evaluation, and stress cycle of several ranges of amplitude has to be considered in assessing damage from fatigue. Generally, cumulative usage factor is applied in this type of evaluation. In this study, in order to confirm applicability of modified rate approach method together with cumulative usage factor, tests were carried out by combining stress cycle blocks of different strain amplitude levels, in which temperature changes in response to strain change in a simulated PWR environment.
3
Fukuta, Yuichi, Seiji Asada, Yuichiro Nomura, and Hiroshi Kanasaki. "Examination of Factors in the Modified Rate Approach Method Under Various Conditions." In ASME 2011 Pressure Vessels and Piping Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/pvp2011-57435.
Abstract:
Fatigue life in elevated-temperature water is affected by water chemistry, temperature, and strain rate. To evaluate these effects, the environmental fatigue life correction factor was established. And to evaluate fatigue damage in actual plants where factors such as temperature and strain rate are not constant, the modified rate approach method was developed. In order to confirm the applicability of these methods, several tests were carried out under a condition in which strain rate changes in response to temperature and fatigue life could be evaluated with an accuracy of a factor of 3, but conservatism was observed. In this evaluation, conservatism of environmental fatigue prediction is studied. To minimize conservatism in environmental fatigue evaluation, four factors are examined. As a result of examination, we conclude that an improvement the environmental fatigue life correction factor and application of a strain range insensitive to the environment may reduce conservatism, and that investigation into the mechanism of reduction in fatigue life is necessary for further improvement.
4
Tanaka, Masa-aki, and Toshiharu Muramatsu. "Numerical Simualtion of Turbulence Mixing Characteristic in Various Secondary Flow Conditions at T-Junction Piping Systems." In ASME/JSME 2004 Pressure Vessels and Piping Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/pvp2004-3028.
Abstract:
Temperature fluctuation caused by mixing the fluids with different temperature in a T-junction pipe gives eventually thermal fatigue to structure, and this phenomenon is significant as safety issue in liquid metal cooled fast reactor (LMFBR). In Japan Nuclear Cycle Development Institute (JNC), experimental and numerical investigations have been performed to clarify the mixing phenomena in the T-junction pipe and to establish an evaluation rule for design. If the T-junction pipe is set near an elbow pipe, turbulence mixing is surly affected by the secondary flow generated in the elbow pipe and it is necessary to study the influence of the secondary flow on the temperature fluctuation in the T-junction pipe. We carried out investigation into the secondary flow effect by numerical simulation using a quasi-direct numerical simulation code. Numerical simulation is conducted on the existing experiment, in which the test section simulated the T-junction pipe with the elbow pipe in LMFBR. Major parameter in the numerical simulation is the flow direction of the branch pipe to the flow direction of the elbow pipe. We discuss the influences of the secondary flow on turbulent mixing behavior, and also clarify the mixing mechanism in T-junction pipe.
5
Higley, Megan, Mustafa Hadj-Nacer, and Miles Greiner. "Temperature Prediction of a TN-32 Used Nuclear Fuel Canister Subjected to Vacuum Drying Conditions." In ASME 2018 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/pvp2018-84844.
Abstract:
In this work, a geometrically-accurate two-dimensional (2D) computational fluid dynamic (CFD) model of a used nuclear fuel cask, that can contain up to 32 pressurized water reactor (PWR) used nuclear fuel (UNF) assemblies, is constructed. This model is similar to the TN-32 cask employed in the ongoing high-burnup (HBU) Spent Fuel Data Project lead by the Electric Power Research Institute (EPRI). This model is used to predict the peak cladding temperature under vacuum drying conditions. Due to the symmetry of the cask, only one-eighth of the cross-section is modeled. Steady-state simulations that include the temperature-jump boundary conditions at the gas-solid interfaces are performed for different heat generation rates in the fuel regions and a range of dry helium pressures, from ∼105 to 100 Pa. These simulations include conduction within solid-gas regions and surface-to-surface radiation across all gas regions. The peak cladding temperatures are reported for various heat generation rates and rarefaction conditions, along with the maximum allowable heat generation that brings the cladding temperatures to the radial hydride formation limit. The results showed that the decrease of helium pressure significantly increased the temperature of the cladding material compared to the atmospheric pressure condition.
6
Pu, Yi-Hao, Tara Larsson, Tom Robeyn, Michel De Paepe, and Sebastian Verhelst. "Methanol Evaporation in an Engine Intake Runner under Various Conditions." In 16th International Conference on Engines & Vehicles. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-24-0018.
Abstract:
<div class="section abstract"><div class="htmlview paragraph">Methanol has recently emerged as a promising fuel for internal combustion engines due to its multiple carbon-neutral production routes and advantageous properties when combusting. Methanol is intrinsically more suitable for spark-ignition (SI) operation thanks to its high octane number, but its potential in heavy-duty applications also encourages engine manufacturers in this field to retrofit their existing compression-ignition products into methanol/diesel dual-fuel (DF) operation. For both SI operation and DF operation, injecting methanol into the engine’s intake path at low pressure is a relatively simple and robust method to introduce methanol into the cylinders. However, the much higher heat of vaporization (HoV) of methanol compared to conventional SI fuels like gasoline can be a double-edged sword. On the one hand, its enhanced cooling effect may increase volumetric efficiency and lower knock tendency, on the other hand, the extra heat it absorbs when evaporating may pose cold-start issues and lead to unstable combustion. To further investigate, a special experimental setup was built. Multiple thermocouples were mounted on an intake runner where the fuel is injected to monitor the temperature changes of the flow before and after injection. The temperature of the runner itself was also monitored to assess the heat taken from the metal wall of the runner pipe. Different air-fuel ratios, air temperatures, air pressures, and air mass flow rates were tested to evaluate their influences on methanol evaporation. The test results were then compared with conventional gasoline operation. It was found that the temperature drop after fuel injection is strongly dependent on the flow temperature, and that the evaporated fraction of methanol was far lower than that of gasoline even with higher flow temperature. Their very different evaporation behaviors are thoroughly discussed.</div></div>
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Solin, Jussi, Sven Reese, H. Ertugrul Karabaki, and Wolfgang Mayinger. "Fatigue Performance of Stabilized Austenitic Stainless Steels: Experimental Investigations Respecting Operational Relevant Conditions Like Temperature and Hold Time Effects." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97502.
Abstract:
Experimental research on fatigue performance of niobium stabilized stainless steel (1.4550, X6CrNiNb1810mod) relevant for German NPP primary piping demonstrated good long life performance. Fatigue tests periodically interrupted for holds indicated time and temperature dependent hardening during holds at 25°C to 325°C. Notable extension of fatigue life was measured when loading patterns consist of cyclic deformation in lower temperatures than hold annealing. Many NPP piping thermal transients separated by normal operation belong to this category and fatigue assessment based on standard fatigue data seems to underestimate fatigue endurance. Further results for stabilized stainless steel in air at various temperatures will be provided. A parallel paper will deliver unpublished data in PWR water. The influences of temperature and loading pattern will be discussed aiming to improve fatigue assessment of plant components and to reduce confusion concerning applicability of international design codes.
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Yamamoto, Masato, Akihiko Kimura, Kunio Onizawa, Kentaro Yoshimoto, Takuya Ogawa, Yasuhiro Mabuchi, Hans-Werner Viehrig, Naoki Miura, and Naoki Soneda. "A Round Robin Program of Master Curve Evaluation Using Miniature C(T) Specimens: 3rd Report — Comparison of T0 Under Various Selections of Temperature Conditions." In ASME 2014 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/pvp2014-28898.
Abstract:
The Master Curve approach for the fracture toughness evaluation is expected to be a powerful tool to ensure the reliability of long-term used RPV steels. In order to get sufficient number of data for the Master Curve approach coexistent with the present surveillance program for RPVs, the utilization of miniature specimens, which can be taken from broken halves of surveillance Charpy specimens, is important. CRIEPI developed the test technique for the miniature C(T) specimens (Mini-CT), whose dimensions are 4 × 10 × 10 mm, and verified the basic applicability of Master Curve approach by means of Mini-CT for the determination of fracture toughness of typical Japanese RPV steels. A round robin program is organized in order to assure the robustness of the testing procedure to the difference in testing machines or operators. The first and second round robin tests (PVP2012-78661 [1], PVP2013-97936 [2]) suggested that the reference temperature T0 evaluation technique by Mini-CT specimen potentially is fairly robust in regard to difference in testing machines and operators, and gives similar loading rate dependency to the larger C(T) specimens. As the final year of the round robin program, “blind tests” were carried out. Here, detailed material information such as the type of materials, estimated T0, existing fracture toughness data for the material, were not given with the specimen, and 6 organizations independently selected the test temperature based on Charpy full curve of the tested material. The selection of test temperature has the variation of −120 °C to −150 °C among the organizations. 8 to 20 specimens in a set were subjected to the Master Curve evaluation and all the 6 organizations successfully obtained valid T0. The scatter range in T0 was at most 16 °C, which was within the acceptable scatter range specified in ASTM E1921-10e1. The selection of test temperature seems to give limited effect as like as that in larger specimens.
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Tateno, Masayoshi, and Eiichiro Yokoi. "Dependence of Tensile Strength on Geometrical Interface Conditions of Bonded Dissimilar Materials." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97731.
Abstract:
Many engineering structures applied for generating energy are said to have been requiring high strength under high temperature conditions. Fine ceramic is expected to be useful in structural applications in various industries by joining to metals. Ceramic can be used in structural parts for engineering where resistance to high temperature and/or high strength are required from the viewpoint of the optimum structural design. Use of ceramic for engineering structures by joining to metal generates a bonded interface between the ceramic and metal.
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Williams, Bruce W., and C. Hari M. Simha. "Comparison of Various Damage Models in Modelling 3D Crack Propagation." In ASME 2016 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/pvp2016-63082.
Abstract:
It is of interest to model crack propagation in irradiated Zr-2.5Nb nuclear pressure tubes and X70 pipeline steel. These materials can undergo a range of conditions leading to fracture with operating temperatures between room temperature and 300 °C for Zr-2.5Nb and strain-rates ranging from quasi-static to dynamic in the case of pipeline steel. In the case of the hexagonal closed-packed zirconium alloy, the influence of plastic anisotropy is also of interest. When trying to capture the fracture response under a wide variety of conditions, limitations of traditional Linear Elastic and Elastic Plastic Fracture Mechanics become apparent such as trying to capture effects of crack tunnelling, the transition from flat-to-slant fracture, and anisotropy. Various damage mechanics based approaches to model 3D crack propagation will be presented and discussed including the crack tip opening angle, a Gurson-Tvergaard-Needleman type damage model based on void nucleation, growth, and coalescence, and the Xue and Wierzbicki model based on the relationship between failure strain with stress triaxiliaty and lode angle dependence. A non-local damage scheme, which mitigates the mesh-dependence of results, will also be presented. For Zr-2.5Nb pressure tube, simulations were performed using Hill’48 and Cazacu-Barlat-Plunkett 2006 anisotropy yield functions. Experimental data from compact tension and rising pressure burst tests on irradiated Zr-2.5Nb pressure tube and both static and dynamic drop weight tear tests on X70 pipeline steel will be compared to predictions from finite element simulations. It is shown that simulations using the various damage models can capture the measured crack propagation behaviour, including crack tunnelling, to varying degrees of accuracy. The Xue and Wierzbicki fracture model was shown to capture the transition from a flat, tunnelling (ductile fracture) crack to a slanted (shear fracture) crack during propagation that was observed in both Zr-2.5Nb and pipeline steel.
Reports on the topic "Various pressure and temperature conditions":
1
Witte, Hawley, and Grimley. PR-015-12601-R01 USM Accuracy Effects with Pressure and Temperature Variations from Initial Calibration. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 2013. http://dx.doi.org/10.55274/r0010810.
Abstract:
Static environmental chamber tests and flow tests at various pressure and temperature conditions were conducted to determine the effects on flow measurement values for two ultrasonic meters from two different manufacturers. Mechanical dimension changes produced by stress from pressure and thermal expansion or contraction at state conditions different from dry calibration and flow calibration conditions in the meters were predicted. The predicted flow measurement error was compared with the actual flow measurement error.
2
Bajwa, Abdullah, and Timothy Jacobs. PR-457-17201-R01 Residual Gas Fraction Estimation Based on Measured In-Cylinder Pressure. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), September 2018. http://dx.doi.org/10.55274/r0011519.
Abstract:
Developing a reliable means of predicting and controlling engine operation at various operating conditions may be a reasonable pathway for meeting increasingly stringent engine emission regulations. In order to do so, estimates of the mixture composition at the end of the gas exchange process (i.e. at exhaust port closure, or EPC) are helpful for having accurate models of engine combustion. A substantial fraction of the trapped charge mixture is composed of residual gases from previous cycles. This fraction, the trapped residual fraction, changes combustion characteristics of the trapped mixture. Residual gases dilute the fresh charge, thus decreasing the flame speed and temperature. Moreover, because of their spatial inhomogeneity, especially around the spark plug, these gases seem to have implications for engine stability. All these factors likely affect engine performance and emissions. Unfortunately, it is not practical to directly measure the trapped residual fraction for engines operating in the field. To overcome this, computational models can be developed for control applications which estimate this fraction based on some measurable engine parameters e.g. manifold pressures, temperatures, etc. Currently, such models aren't readily available for stationary two-stroke natural-gas engines. This report summarizes the results of phase I of a multi-phase project. In this phase a GT-Power based model was developed for an Ajax E-565 single-cylinder engine to study various factors that influence the removal, or lack thereof, of residual gases from the engine cylinder. The model was used to successfully simulate various engine operating conditions and study the scavenging characteristics of the engine. Various steps followed in the development of the model have been discussed in the report, and at the end some preliminary results and recommendations for the next phase of the project have been presented.
3
Grauer and Chapman. L52331 Exhaust Manifold Design Guidelines to Optimize Scavenging and Turbocharger Performance. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2009. http://dx.doi.org/10.55274/r0010664.
Abstract:
To develop the requisite air flow rate, the turbocharger must operate at a relatively high efficiency. But as important, the system pressure losses must be minimized to optimize turbocharger operating flexibility so that the turbine can produce sufficient power to operate the turbocharger compressor. The relationship between the various pressures and pressure losses throughout the turbocharged engine system, the turbocharger overall efficiency, ambient conditions, and the required turbine inlet temperature for sustainability is rooted in fundamental thermodynamic principles. The goal of the Exhaust Manifold Design Guidelines project was to investigate the NOX reduction role played by the exhaust manifold by exploring the impact of the exhaust manifold design on turbocharger and engine operation, as well as utilizing the abundant sets of field test data already provided by Hoerbiger Engineering Services (HES). For this project, exhaust manifold performance was defined as the capacity of the exhaust manifold to: 1) optimize cylinder scavenging efficiency; and 2) minimize the pressure differential between the compressor discharge and the turbine inlet.
4
King. L52120 Long-Term Environmental Monitoring of Near-Neutral and High-pH SCC Sites. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2005. http://dx.doi.org/10.55274/r0011228.
Abstract:
The aims of this project were (i) to monitor the seasonal variation of environmental conditions at stress corrosion cracking (SCC) sites and (ii) to develop an improved site-selection model for SCC. Environmental and other relevant data have been collected for a total of nine known, or suspected, SCC sites; seven near-neutral pH SCC and two high-pH SCC.� The presence of SCC was determined, or predicted, based on in-service or hydrotest failures, excavation, industry soils model, or ILI.� Pipe-depth environmental conditions were monitored continuously for periods of up to 2 years using the permanent NOVAProbe, which is capable of measuring the local redox potential, soil resistivity, pH and temperature close to the pipe surface.� Corrosion coupons were also installed at some sites to monitor the CP conditions and native potential.� In addition, various other information was collected for each site, including pipe information; soil, groundwater, coating, and corrosion product samples; topography and land use; precipitation data; soil gas samples; SCADA pressure data; corrosion and SCC ILI information; CIS data; gas temperature (for high-pH SCC sites); and information about the nature of the SCC.� All sites studied were on gas transmission pipelines in Canada.
5
Author, Unknown. PR-203-027-R01 Evaluation of Screen Testing Program for J-Lay Connections. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 1992. http://dx.doi.org/10.55274/r0012125.
Abstract:
This report discusses the results of a testing program designed to simulate the operational conditions imposed on a J-lay installed, 13%" subsea pipeline assembled with mechanical connections. The program objective was to gain an understanding of the long-term sealing integrity of various mechanical connections. The connections were subjected to combinations of cyclic internal pressure, cyclic temperature, axial compression, and reverse torsion. The testing results show that the mechanically interlocked Reflange C-Con II connection and two premium threaded connections, the Hunting Fox and Sumitomo Varn Ace, when assembled utilizing suitable bonding agents, successfully resisted the imposed loads of this testing program. In addition, the selection of a proper bonding agent or adhesive to prevent reverse torque back out proved to be important as several of these agents were unreliable in preventing back out failures. The testing conditions applied to the mechanical connections in this test program are believed to be conservative, exceeding the maximum that in-service, J-lay installed pipelines are likely to experience. Therefore, this test program may be used to select a pipeline connection for this duty.
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Mohr, H. O. PR-209-9217-R01 Mechanical Connections for J-lay. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 1994. http://dx.doi.org/10.55274/r0012126.
Abstract:
This report discusses the results of a testing program designed to simulate the operational conditions imposed on a J-lay installed, 13%" subsea pipeline assembled with mechanical connections. The program objective was to gain an understanding of the long-term sealing integrity of various mechanical connections. The connections were subjected to combinations of cyclic internal pressure, cyclic temperature, axial compression, and reverse torsion. The testing results show that the mechanically interlocked Reflange C-Con II connection and two premium threaded connections, the Hunting Fox and Sumitomo Varn Ace, when assembled utilizing suitable bonding agents, successfully resisted the imposed loads of this testing program. In addition, the selection of a proper bonding agent or adhesive to prevent reverse torque back out proved to be important as several of these agents were unreliable in preventing back out failures. The testing conditions applied to the mechanical connections in this test program are believed to be conservative, exceeding the maximum that in-service, J-lay installed pipelines are likely to experience. Therefore, this test program may be used to select a pipeline connection for this duty.
7
Wilson. PR-239-9525-E01 Integrated Test Plan. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 1996. http://dx.doi.org/10.55274/r0011046.
Abstract:
In order to understand and eventually control formaldehyde emissions, it is necessary to investigate formaldehyde formation mechanisms and evaluate the applicability of these mechanisms to industrial gas engines. An extensive literature review was conducted to identify possible formaldehyde formation mechanisms, factors that favor these chemical mechanisms, and the relationships between various engine operating conditions and engine-out formaldehyde emissions. The literature review provided the following information on formaldehyde emissions: Formation and subsequent destruction of formaldehyde are necessary intermediate steps in the complete combustion of natural gas; Regions within the combustion chamber processed by propagating flames are not likely sources of formaldehyde; Identification of a distinct 'temperature window' where net formaldehyde formation occurs, provided that adequate oxygen and unburned hydrocarbons are present; Above the 'temperature window' formaldehyde is quickly destroyed, and below it formaldehyde mole fractions are frozen; and Emissions of formaldehyde from natural gas fired engines require that partial combustion, to some degree, take place in the cylinder. This finding is supported by results of equilibrium calculations of natural gas combustion product composition, which do not predict significant levels of formaldehyde. A number of publications have been produced from the integrated test plan body of work. Those publications include reports on the formaldehyde literature review, humidity test program, and the high pressure injection project and technical papers on formaldehyde literature review, high pressure injection, the tracer gas method, in-cylinder sampling, and humidity investigations. The work described in the humidity and high pressure injection reports is not covered in detail in this document. However, the results are discussed as needed to support data interpretation and conclusions. Includes a literature review of mixing and humidity effects as well as a spreadsheet of the test data.
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Beshouri. PR-309-04200-R01 Modeling Methodology for Parametric Emissions Monitoring System for Combustion Turbines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2005. http://dx.doi.org/10.55274/r0010731.
Abstract:
Prior attempts to develop a generic Parametric Emissions Monitoring methodology for combustion turbines, particularly low emissions units, have failed due either to the reduction of a complex problem to too few degrees of freedom or the brute force reliance on regression analysis. Field test data collected by the research team clearly illustrated that a successful PEMS model will need to incorporate multiple zones to account for pilot fuel versus pre-mixed combustion, and changes in air/fuel ratio at the flame front. The information reported herein shows that, ideally, the PEMS model should rely on speed, fuel flow, compressor discharge pressure and temperature, and ambient conditions as the inputs. The model can utilize (combustion turbine) turbine discharge temperatures as cross checks and/or for tuning. Make and model specific geometric characteristics should include compressor air flow versus speed, air splits between the combustor and the cooling air, and the fuel splits between diffusion and premixed. Finally, the model should be able to accommodate fuel that varies in composition based on provided gas speciation.
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George. PR-015-10600-R01 Proposed Sampling Methods for Supercritical Natural Gas Streams. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 2010. http://dx.doi.org/10.55274/r0010981.
Abstract:
Deepwater natural gas production is a non-traditional operation that is very different than conventional shelf or onshore production, due to the extremely high pressures (2,000 psia, 13.8 MPa abs) and rich gases (1,300 Btu/scf, 48.4 MJ/Nm3) involved. Concerns have been raised about methods used to sample deepwater natural gas supplies in this supercritical state. Sampling methods accepted for natural gas at pipeline conditions have been used to sample gas from offshore platforms and supercritical onshore storage facilities. However, the sample analyses have later been found to overestimate the energy content of the gas by as much as 300 Btu/scf (11.2 MJ/Nm3). Analyses of these samples have also been found to incorrectly estimate other properties of the gas, such as sound speed and density. Due to the potential financial impact of such discrepancies, the need exists to understand their causes, and to identify alternative sampling procedures or methods that can minimize them. A literature search was performed to identify sampling methods with the potential to accurately sample natural gas streams in the supercritical region. The search included methods listed in existing natural gas sampling standards, such as API MPMS Chapter 14.1 and GPA 2166-05, variations and suggested improvements on these standard methods, and sampling methods applied in other sectors of the energy industry. No sampling methods were identified that are designed specifically for sampling supercritical natural gas. However, guidelines were found in various references that are useful in tailoring existing sampling methods or designing new sampling methods for supercritical gas service. These guidelines include means to avoid phase changes in the samples, methods of regulating pressure while maintaining sample temperatures, avoiding issues with adsorption and desorption on equipment, and recommendations for designing a sampling method for high-pressure service.
10
Tawfik, Aly, Deify Law, Juris Grasis, Joseph Oldham, and Moe Salem. COVID-19 Public Transportation Air Circulation and Virus Mitigation Study. Mineta Transportation Institute, June 2022. http://dx.doi.org/10.31979/mti.2021.2036.
Abstract:
COVID-19 may have forever changed our world. Given the limited space and air circulation, potential infections on public transportation could be concerningly high. Accordingly, this study has two objectives: (1) to understand air circulation patterns inside the cabins of buses; and (2) to test the impact of different technologies in mitigating viruses from the air and on surfaces inside bus cabins. For the first objective, different devices, metrics and experiments (including colored smoke; videotaping; anemometers; pressure differentials; particle counts; and 3D numerical simulation models) were utilized and implemented to understand and quantify air circulation inside different buses, with different characteristics, and under different operating conditions (e.g. with windows open and shut). For the second objective, three different live prokaryotic viruses were utilized: Phi6, MS2 and T7. Various technologies (including positive pressure environment inside the cabin, HEPA filters with different MERV ratings, concentrated UV exposure with charged carbon filters in the HVAC systems, center point photocatalytic oxidation technology, ionization, and surface antiviral agents) were tested to evaluate the potential of mitigating COVID-19 infections via air and surfaces in public transportation. The effectiveness of these technologies on the three live viruses was tested in both the lab and in buses in the field. The results of the first objective experiments indicated the efficiency of HVAC system designs, where the speed of air spread was consistently much faster than the speed of air clearing. Hence, indicating the need for additional virus mitigation from the cabin. Results of the second objective experiments indicated that photocatalytic oxidation inserts and UVC lights were the most efficient in mitigating viruses from the air. On the other hand, positive pressure mitigated all viruses from surfaces; however, copper foil tape and fabrics with a high percentage of copper mitigated only the Phi6 virus from surfaces. High-temperature heating was also found to be highly effective in mitigating the different viruses from the vehicle cabin. Finally, limited exploratory experiments to test possible toxic by-products of photocatalytic oxidation and UVC lights inside the bus cabin did not detect any increase in levels of formaldehyde, ozone, or volatile organic compounds. Implementation of these findings in transit buses, in addition to the use of personal protective equipment, could be significantly valuable for protection of passengers and drivers on public transportation modes, possibly against all forms of air-borne viruses.