Exact Solution for Freezing in Cylindrical Symmetry with Extended Freezing Temperature Range

1979 ◽  
Vol 101 (2) ◽  
pp. 331-334 ◽  
Author(s):  
M. N. O¨zis¸ik ◽  
J. C. Uzzell
Keyword(s):  
Solid Solution ◽  
Solid Fraction ◽  
Freezing Temperature ◽  
Cylindrical Symmetry ◽  
Infinite Medium ◽  
The Other ◽  
Phase Zone ◽  
Two Phase ◽  
Temperature Range ◽  
Liquidus Temperatures

The problem of solidification by a line heat sink in an infinite medium with cylindrical symmetry for a substance having an extended freezing temperature range between the solidus and liquidus temperatures is solved exactly for two different cases characterizing the distribution of the solid fraction within the two-phase zone. In one of the models, the solid fraction is assumed to vary linearly with the temperature and in the other solidification within the two-phase zone is assumed to have a linear relationship with the distance. The analysis is applicable for both eutectic and solid solution alloys.

scholarly journals Effect of temperature on growth of Pseudomonas protegens Pf-5 and Pseudomonas aeruginosa PRD-10 in LB Lennox medium

2018 ◽  
Author(s):  
Wenfa Ng
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Optical Density ◽  
The Other ◽  
Temperature Adaptation ◽  
Effect Of Temperature ◽  
Metabolic Processes ◽  
Two Phase ◽  
Ph Variation ◽  
Temperature Range ◽  
Other Hand

Temperature affects growth of bacteria by influencing enzyme and growth kinetics. Specifically, evolution selects for specific temperature range in which a microbe could thrive, and thus fix the temperature range in which biomolecule structure and function are finely tuned for coping with the thermal conditions prevailing within a cell at a particular temperature. Using aerobic culture in LB Lennox medium in shake flasks, this study aimed to understand the growth of Pseudomonas protegens Pf-5 (ATCC BAA-477) and Pseudomonas aeruginosa PRD-10 (ATCC 15442) at 25, 30 and 37 oC. Experiment results revealed that P. protegens Pf-5 grew very poorly at 37 oC (with maximal optical density of 0.66), while better growth was observed at 25 and 30 oC. Specifically, P. protegens Pf-5 appeared to be better adapted to growth at 25 oC, where the maximal optical density obtained was 5.3 compared to 4.6 at 30 oC. More importantly, two phase growth behaviour was observed during growth at 30 oC where a faster initial phase of growth was followed by a slower one. Growth at 25 and 30 oC exhibited similar pH trend, which suggested similar metabolic processes was activated during growth. On the other hand, P. aeruginosa PRD-10 demonstrated a more efficient conversion of LB Lennox medium into biomass where the maximal optical density obtained at all three growth temperatures were higher than those of P. protegens Pf-5. More importantly, growth of P. aeruginosa PRD-10 exhibited a clear adaptation to growth at 25 and 37 oC, while growth at 30 oC resulted in a lower biomass yield compared to that of 25 and 37 oC. On the other hand, pH variation during culture revealed that P. aeruginosa PRD-10 likely activated similar metabolic processes at all three growth temperatures, where a higher growth temperature would result in the net secretion of more alkaline metabolites. Collectively, P. protegens Pf-5 and P. aeruginosa PRD-10 demonstrated clear temperature adaptation at an evolutionary level. In addition, experiment data suggested that P. aeruginosa PRD-10 might have co-evolved with humans on a substantial time scale resulting in a temperature preference of 37 oC over 30 oC.

scholarly journals Effect of temperature on growth of Pseudomonas protegens Pf-5 and Pseudomonas aeruginosa PRD-10 in LB Lennox medium

2018 ◽  
Author(s):  
Wenfa Ng
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Optical Density ◽  
The Other ◽  
Temperature Adaptation ◽  
Effect Of Temperature ◽  
Metabolic Processes ◽  
Two Phase ◽  
Ph Variation ◽  
Temperature Range ◽  
Other Hand

Temperature affects growth of bacteria by influencing enzyme and growth kinetics. Specifically, evolution selects for specific temperature range in which a microbe could thrive, and thus fix the temperature range in which biomolecule structure and function are finely tuned for coping with the thermal conditions prevailing within a cell at a particular temperature. Using aerobic culture in LB Lennox medium in shake flasks, this study aimed to understand the growth of Pseudomonas protegens Pf-5 (ATCC BAA-477) and Pseudomonas aeruginosa PRD-10 (ATCC 15442) at 25, 30 and 37 oC. Experiment results revealed that P. protegens Pf-5 grew very poorly at 37 oC (with maximal optical density of 0.66), while better growth was observed at 25 and 30 oC. Specifically, P. protegens Pf-5 appeared to be better adapted to growth at 25 oC, where the maximal optical density obtained was 5.3 compared to 4.6 at 30 oC. More importantly, two phase growth behaviour was observed during growth at 30 oC where a faster initial phase of growth was followed by a slower one. Growth at 25 and 30 oC exhibited similar pH trend, which suggested similar metabolic processes was activated during growth. On the other hand, P. aeruginosa PRD-10 demonstrated a more efficient conversion of LB Lennox medium into biomass where the maximal optical density obtained at all three growth temperatures were higher than those of P. protegens Pf-5. More importantly, growth of P. aeruginosa PRD-10 exhibited a clear adaptation to growth at 25 and 37 oC, while growth at 30 oC resulted in a lower biomass yield compared to that of 25 and 37 oC. On the other hand, pH variation during culture revealed that P. aeruginosa PRD-10 likely activated similar metabolic processes at all three growth temperatures, where a higher growth temperature would result in the net secretion of more alkaline metabolites. Collectively, P. protegens Pf-5 and P. aeruginosa PRD-10 demonstrated clear temperature adaptation at an evolutionary level. In addition, experiment data suggested that P. aeruginosa PRD-10 might have co-evolved with humans on a substantial time scale resulting in a temperature preference of 37 oC over 30 oC.

Two phase diagrams of Pb(Ti0.485Zr0.515)0.98(Nb0.5Bi0.5)0.02O3 solid solution in the temperature range 20 ≤ t ≤ 600°C

2014 ◽  
Vol 59 (5) ◽  
pp. 713-717 ◽  
Author(s):  
L. A. Shilkina ◽  
A. V. Pavlenko ◽  
L. A. Reznichenko ◽  
S. I. Dudkina
Keyword(s):  
Solid Solution ◽  
Phase Diagrams ◽  
Two Phase ◽  
Temperature Range

Effect of Ta addition on microstructure and mechanical properties of dual two-phase Ni3Al-Ni3V intermetallic alloy–Retraction

MRS Advances ◽  
2019 ◽  
Vol 4 (25-26) ◽  
pp. 1509-1514 ◽  
Author(s):  
Kazushige Ioroi ◽  
Yasuyuki Kaneno ◽  
Takayuki Takasugi
Keyword(s):  
Solid Solution ◽  
Volume Fraction ◽  
Intermetallic Alloy ◽  
The Other ◽  
Solid Solution Hardening ◽  
Solution Hardening ◽  
Two Phase ◽  
Atomic Size ◽  
Microstructural Observation ◽  
Hardening Behavior

ABSTRACTMechanism for the hardening of two-phase Ni3Al-Ni3V intermetallic alloy to which 2 at.% Ta was added in different substitution manners for Ni, Al and V was presented, based on the microstructural observation, alloying behavior and lattice properties of the additive in the constituent phases. The hardening behavior was explained in terms of solid solution hardening in which the mixture rule in the volume fraction of the two constituent phases and the atomic size misfit evaluated from the changes of the lattice parameters were incorporated. Consequently, the hardening for the alloys in which the additives were substituted for Ni and V was attributed to solid solution hardening. On the other hand, the hardening for the alloy in which the additive was substituted for Al was attributed to the hardening due to microstructural refining in addition to the solid solution hardening.

Freezing Flow in a Subcooled Permeable Medium

1992 ◽  
Vol 114 (4) ◽  
pp. 1036-1041 ◽  
Author(s):  
S. K. Griffiths ◽  
R. H. Nilson
Keyword(s):  
Freezing Point ◽  
Freezing Temperature ◽  
Similarity Solutions ◽  
Inlet Temperature ◽  
Governing Equations ◽  
Phase Zone ◽  
Two Phase ◽  
Liquid Zone ◽  
One Dimensional ◽  
Order Of Magnitude

Analytical similarity solutions are derived for the problem of transient one-dimensional flow and freezing of a liquid in an initially dry permeable half-space. The structure of the flow consists of three regions: a liquid zone in which the temperature decreases to the freezing temperature, a central two-phase zone where the temperature is at the freezing point, and a leading gas-filled region in which the temperature is nearly undisturbed. The propagation velocity of this intrusion is determined as a function of the subcooling, latent heat, and other process parameters. As the inlet temperature approaches the freezing temperature, the governing equations admit a pair of solutions having propagation velocities that sometimes differ by more than an order of magnitude.

Study of the Coefficient of Thermal Expansion for Steel Q235

2011 ◽  
Vol 194-196 ◽  
pp. 326-330 ◽  
Author(s):  
Jian Xun Fu ◽  
Xiang Dong Li ◽  
Weng Sing Hwang
Keyword(s):  
Thermal Expansion ◽  
Coefficient Of Thermal Expansion ◽  
Eutectoid Reaction ◽  
Cooling Process ◽  
Temperature Zone ◽  
Phase Zone ◽  
Two Phase ◽  
Model Calculations ◽  
Temperature Range ◽  
Temperature Crack

The dynamic coefficient of thermal expansion for steel Q235 during cooling was investigated using experimental measurements and model calculations. The coefficient of thermal expansion under 1400°С was measured with a thermal dilatometer. The coefficient was derived from a segregation model of two-phase zone for of temperature range of 1400°С to zero-strength temperature (ZST). The obtained results reveal that the coefficient of thermal expansion shows two jumps in the temperature zone of the peritectic reaction and the eutectoid reaction. The anti-expansion phenomenon caused by the eutectoid reaction in the cooling process corresponds to the low-temperature crack-sensitive area. Therefore, the slab straightening process should be avoided in this temperature range during continuous casting.

Transition alpha structure in beta-isomorphous Nb-Hf alloys

1987 ◽  
Vol 45 ◽  
pp. 232-233
Author(s):  
R.W. Carpenter ◽  
Changhai Li ◽  
David J. Smith
Keyword(s):  
Solid Solution ◽  
Solution Phase ◽  
Miscibility Gap ◽  
Large Strains ◽  
Solid Solution Phase ◽  
Two Phase ◽  
Diffuse Intensity ◽  
Metastable Form ◽  
The Matrix ◽  
Equilibrium Morphology

Binary Nb-Hf alloys exhibit a wide bcc solid solution phase field at temperatures above the Hfα→ß transition (2023K) and a two phase bcc+hcp field at lower temperatures. The β solvus exhibits a small slope above about 1500K, suggesting the possible existence of a miscibility gap. An earlier investigation showed that two morphological forms of precipitate occur during the bcc→hcp transformation. The equilibrium morphology is rod-type with axes along <113> bcc. The crystallographic habit of the rod precipitate follows the Burgers relations: {110}||{0001}, <112> || <1010>. The earlier metastable form, transition α, occurs as thin discs with {100} habit. The {100} discs induce large strains in the matrix. Selected area diffraction examination of regions ∼2 microns in diameter containing many disc precipitates showed that, a diffuse intensity distribution whose symmetry resembled the distribution of equilibrium α Bragg spots was associated with the disc precipitate.

Gas-Water Flow Behaviour During Mutual Displacement in Porous Media

2017 ◽  
Vol 10 (1) ◽  
pp. 13-22
Author(s):  
Renyi Cao ◽  
Junjie Xu ◽  
Xiaoping Yang ◽  
Renkai Jiang ◽  
Changchao Chen
Keyword(s):  
Porous Media ◽  
Relative Permeability ◽  
Gas Storage ◽  
Fluid Distribution ◽  
Water Displacement ◽  
Phase Zone ◽  
Two Phase ◽  
Flow Process ◽  
Single Well ◽  
Mutual Displacement

During oilfield development, there exist multi-cycle gas–water mutual displacement processes. This means that a cycling process such as water driving gas–gas driving water–water driving gas is used for the operation of injection and production in a single well (such as foam huff and puff in single well or water-bearing gas storage). In this paper, by using core- and micro-pore scales model, we study the distribution of gas and water and the flow process of gas-water mutual displacement. We find that gas and water are easier to disperse in the porous media and do not flow in continuous gas and water phases. The Jamin effect of the gas or bubble becomes more severe and makes the flow mechanism of multi-cycle gas–water displacement different from the conventional water driving gas or gas driving water processes. Based on experiments of gas–water mutual displacement, the changing mechanism of gas–water displacement is determined. The results indicate that (1) after gas–water mutual displacement, the residual gas saturation of a gas–water coexistence zone becomes larger and the two-phase zone becomes narrower, (2) increasing the number of injection and production cycles causes the relative permeability of gas to increase and relative permeability for water to decrease, (3) it becomes easier for gas to intrude and the invaded water becomes more difficult to drive out and (4) the microcosmic fluid distribution of each stage have a great difference, which caused the two-phase region becomes narrower and effective volume of gas storage becomes narrower.

Ethanol conversion over Ga2O3-ZrO2 solid solution: empirical evidences of the reaction pathway, the surface acid–base property, and role of isolated gallium ion

2021 ◽  
Author(s):  
Takashi Yamamoto ◽  
Akihito Kurimoto ◽  
Riona Sato ◽  
Shoki Katada ◽  
Hirotaka Mine ◽  
...  
Keyword(s):  
Solid Solution ◽  
Reaction Pathway ◽  
Ethanol Conversion ◽  
Acid Base ◽  
Base Property ◽  
Temperature Range ◽  
Acid Base Property

Ethanol conversion by Ga2O3-ZrO2 solid solution was examined in the temperature range 573–773 K, and acetone/isobutene formation was confirmed under cofeeding of H2O vapor. The reaction pathway was empirically investigated...

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