scholarly journals The relationship of area under temperature curve during MR guided HIFU and diffusion coefficient in patient screening

2015 ◽  
Vol 3 (S1) ◽  
Author(s):  
Xuedong Yang ◽  
Rong Rong ◽  
Jia Liu ◽  
Juan Wei ◽  
Bilgin Keserci ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Temperature Curve ◽  
Patient Screening ◽  
Relationship Of ◽  
The Relationship ◽  
And Diffusion

Molecular Dynamics Simulation of Al2O3-SiC Interface

2011 ◽  
Vol 697-698 ◽  
pp. 192-197 ◽  
Author(s):  
Ting Ting Zhou ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou ◽  
Hong Tao Zhu
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Interfacial Energy ◽  
Diffusion Coefficients ◽  
Diffusion Mechanism ◽  
Dynamics Simulation ◽  
Interface Model ◽  
Relationship Of ◽  
The Relationship ◽  
And Diffusion

The interfacial energy and diffusion phenomenon of the Al2O3(012)-SiC (011) interface model are studied based on molecular dynamics. The interfacial energy increases firstly until reaches its maximum 0.459J/m2at the temperature of 1500K and then decreases. The relationship of diffusion coefficients for each kind of atoms is C>Si>O>Al. Diffusion coefficients of atoms increase at first and then decrease as the temperature goes up. This indicates the diffusion mechanism has been changed during the temperature rising process.

Influence of the Pretreatment on the Concrete Chloride Diffusion Coefficient

2011 ◽  
Vol 477 ◽  
pp. 382-387
Author(s):  
Jia Cheng Li ◽  
Wen Ying Guo ◽  
Jing Wei Wu ◽  
Yi Bo Yang
Keyword(s):  
Diffusion Coefficient ◽  
Concrete Structures ◽  
Chloride Diffusion ◽  
Experimental Result ◽  
Chloride Diffusion Coefficient ◽  
Ultrasonic Bath ◽  
Vacuum Saturation ◽  
Chloride Migration ◽  
Relationship Of ◽  
The Relationship

The pretreatment of concrete rapid chloride migration coefficient (RCM) method in different standard is different in China. However the influence of pretreatment on the experimental result is uncertain, which leads to poor comparability about the results between different standards and trouble in evaluating the durability of concrete structures. The influence of the pretreatment on the chloride diffusion coefficient was studied by contrastive method. On the base of the results a suitable pretreatment of RCM method was proposed. The results are as followings: (1) the influence of pretreatment on the chloride migration coefficient of concrete with 0.45 W/B is insignificant. The influence of pretreatment on the chloride migration coefficient of concrete with other W/B is significant, and the influence increase with the lower w/b.; (2) the chloride diffusion coefficient will increase after the ultrasonic bath and vacuum saturation, and the influence of the ultrasonic bath is larger. Considering the judgment to the durability of structure, the ultrasonic bath and the vacuum saturation are suggested to be used; (3) on the condition of the same anode and cathode solution, the chloride diffusion coefficient in accordance with JTG / T B07-01-2006 standard is usually higher than that in accordance with GB/T50082-2009 standard; (4) the relationship of the chloride diffusion coefficient between mortar and concrete specimens is uncertain under different proportion and curing system, so the mortar specimens can not replace the concrete specimens for the RCM method.

A Study about Diffusion Coefficient of Carbon Dioxide in Heavy Oil

2014 ◽  
Vol 962-965 ◽  
pp. 578-582
Author(s):  
Bo Su ◽  
Yong Chen Song ◽  
Yu Liu ◽  
Yue Chao Zhao ◽  
Min Hao ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Oil Recovery ◽  
Heavy Oil ◽  
Initial Pressure ◽  
Gas Diffusion ◽  
Geological Sequestration ◽  
Equilibrium Pressure ◽  
Enhance Oil Recovery ◽  
The Relationship ◽  
And Diffusion

CO2 injection into oil reservoirs can both enhance oil recovery and realize CO2 geological sequestration. The gas diffusion coefficient of CO2 in oil and water is a very important factor for EOR. This paper developed a simple experimental technique for measuring the CO2 diffusion coefficient in heavy oil. In this paper, we find the relationship between initial pressure and diffusion coefficient and equilibrium pressure at the same temperature.

scholarly journals Numerical simulation on the leakage and diffusion of the natural gas of the underground pipeline in the soil

2021 ◽  
Vol 2083 (3) ◽  
pp. 032082
Author(s):  
Meijuan Hu ◽  
He Li ◽  
Li Chen ◽  
Ping Xie ◽  
Zheju Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Natural Gas ◽  
Internal Pressure ◽  
Finite Model ◽  
Soil Environment ◽  
Leakage Model ◽  
Relationship Of ◽  
The Relationship ◽  
And Diffusion ◽  
Variation Trends

Abstract For the transportation pipeline with the diameter 1.219 m and the internal pressure 3-12 MPa, the leakage and diffusion of the natural gas of the pipeline in the soil was studied by numerical simulation. First, the finite model containing both pipeline and soil was established, and the porous media was used to simulate the real soil environment. And, the leakage amount of the natural gas was calculated at the cases with different porosities, the pressures inside the pipeline and the diameters of leakage port. Based on the classical theoretical leakage model of small hole in the air and simulation results analysis, the formula of the leakage amount was modified by the soil coefficient α to be suitable for soil environment. Then, the variation trends of the diffusion concentration of methane along different directions in the soil were analyzed by simulation, the influences of internal pressure of pipeline, the diameter of leakage and the porosity of soil were also discussed. Besides, the relationship of the safety distance with time was obtained.

scholarly journals Influence of Concentration Distribution on Cross Diffusion Level in Building Room

2021 ◽  
Vol 248 ◽  
pp. 01043
Author(s):  
Du Zhehua
Keyword(s):  
Diffusion Coefficient ◽  
Concentration Distribution ◽  
Initial Temperature ◽  
Gas Concentration ◽  
Cross Diffusion ◽  
Temperature And Humidity ◽  
Diffusion Character ◽  
Relationship Of ◽  
The Relationship ◽  
Vapor Mass

The relationship of contaminant gas concentration distribution influence on cross diffusion character and level among temperature, humidity and contaminant gas concentration was obtained according to the non-equilibrium thermodynamic theory. The cross diffusion character and level under different contaminant gas concentration distribution were discussed, combining real temperature and humidity in building room. The results show that temperature grads and vapor mass grads are less than zero when contaminant gas mass grads and additional diffusion coefficient are both positive or negative, otherwise the two grads are more than zero. And the higher the initial temperature and humidity levels, the greater the absolute values of temperature grads and vapor mass grads, with the same contaminant gas mass grads and additional diffusion coefficient. While the influence of initial temperature level is finite, and that of initial humidity level is remarkable.

CO2 SOLUBILITY AND DIFFUSIVITY AND RAPID GAS DECOMPRESSION RESISTANCE OF ELASTOMERS CONTAINING CNT

2017 ◽  
Vol 90 (3) ◽  
pp. 562-574 ◽  
Author(s):  
Xuming Chen ◽  
Hamid A Salem ◽  
Ray Zonoz
Keyword(s):  
Gravimetric Method ◽  
Butadiene Rubber ◽  
Structure Property ◽  
Co2 Solubility ◽  
High Pressure High Temperature ◽  
Sealing Performance ◽  
Carbon Dioxide Co2 ◽  
Relationship Of ◽  
The Relationship ◽  
And Diffusion

ABSTRACT Understanding the structure–property relationship of elastomers is of critical importance in developing next-generation elastomers for high-pressure, high-temperature (HPHT) applications and in extending the application temperature and pressure range of existing oilfield products. Gas dissolution and diffusion in elastomers are essential to understanding the relationship among elastomer structures, rapid gas decompression (RGD) resistance, and sealing performance. Solubility and diffusivity (or diffusion efficiency) of carbon dioxide (CO2) in hydrogenated nitrile butadiene rubber (HNBR) and fluoroelastomers (FKM) comprising carbon nanotubes (CNT) were measured using a gravimetric method. The Rubotherm method was also used to estimate the solubility and swelling of HNBR in both subcritical liquid and supercritical CO2. It was demonstrated that CNT had a direct impact on CO2 solubility, diffusion, and mechanical properties of elastomers, hence improving the RGD resistance of the elastomers.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

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