scholarly journals Physical and Chemical Structure of Protoplanetary Disks with Grain Growth

2006 ◽  
Vol 642 (2) ◽  
pp. 1152-1162 ◽  
Author(s):  
Y. Aikawa ◽  
H. Nomura
Keyword(s):  
Grain Growth ◽  
Chemical Structure ◽  
Protoplanetary Disks ◽  
Physical And Chemical

scholarly journals UV-controlled physical and chemical structure of protoplanetary disks

2011 ◽  
pp. 33-38
Author(s):  
V. V. Akimkin ◽  
Y. N. Pavlyuchenkov ◽  
A. I. Vasyunin ◽  
D. S. Wiebe ◽  
M. S. Kirsanova ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Protoplanetary Disks ◽  
Physical And Chemical

scholarly journals UV-controlled physical and chemical structure of protoplanetary disks

2011 ◽  
Vol 335 (1) ◽  
pp. 33-38 ◽  
Author(s):  
V. V. Akimkin ◽  
Y. N. Pavlyuchenkov ◽  
A. I. Vasyunin ◽  
D. S. Wiebe ◽  
M. S. Kirsanova ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Protoplanetary Disks ◽  
Physical And Chemical

scholarly journals Unveiling the physical and chemical conditions in the young disk around L1527

2017 ◽  
Vol 13 (S332) ◽  
pp. 121-123
Author(s):  
M. L. R. van ’t Hoff ◽  
J. J. Tobin ◽  
D. Harsono ◽  
E. F. van Dishoeck
Keyword(s):  
Spatial Distribution ◽  
Chemical Structure ◽  
Protoplanetary Disks ◽  
Young Stars ◽  
Kinetic Temperature ◽  
Temperature Structure ◽  
Chemical Conditions ◽  
Embedded Disks ◽  
Physical And Chemical ◽  
Co Emission

AbstractPlanets form in disks around young stars. The planet formation process may start when the protostar and disk are still deeply embedded within their infalling envelope. However, unlike more evolved protoplanetary disks, the physical and chemical structure of these young embedded disks are still poorly constrained. We have analyzed ALMA data for 13CO, C18O and N2D+ to constrain the temperature structure, one of the critical unknowns, in the disk around L1527. The spatial distribution of 13CO and C18O, together with the kinetic temperature derived from the optically thick 13CO emission and the non-detection of N2D+, suggest that this disk is warm enough (≳ 20 K) to prevent CO freeze-out.

scholarly journals Effects of Various Types of Expandable Graphite and Blackcurrant Pomace on the Properties of Viscoelastic Polyurethane Foams

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Rafał Oliwa ◽  
Joanna Ryszkowska ◽  
Mariusz Oleksy ◽  
Monika Auguścik-Królikowska ◽  
Małgorzata Gzik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Structure ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Ftir Analysis ◽  
Limiting Oxygen Index ◽  
Peak Heat Release Rate ◽  
Physical And Chemical ◽  
Scanning Electron

We investigated the effect of the type and amount of expandable graphite (EG) and blackcurrant pomace (BCP) on the flammability, thermal stability, mechanical properties, physical, and chemical structure of viscoelastic polyurethane foams (VEF). For this purpose, the polyurethane foams containing EG, BCP, and EG with BCP were obtained. The content of EG varied in the range of 3–15 per hundred polyols (php), while the BCP content was 30 php. Based on the obtained results, it was found that the additional introduction of BCPs into EG-containing composites allows for an additive effect in improving the functional properties of viscoelastic polyurethane foams. As a result, the composite containing 30 php of BCP and 15 php of EG with the largest particle size and expanded volume shows the largest change in the studied parameters (hardness (H) = 2.65 kPa (+16.2%), limiting oxygen index (LOI) = 26% (+44.4%), and peak heat release rate (pHRR) = 15.5 kW/m2 (−87.4%)). In addition, this composite was characterized by the highest char yield (m600 = 17.9% (+44.1%)). In turn, the change in mechanical properties is related to a change in the physical and chemical structure of the foams as indicated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.

scholarly journals Effects of accretion flow on the chemical structure in the inner regions of protoplanetary disks

2008 ◽  
Vol 495 (1) ◽  
pp. 183-188 ◽  
Author(s):  
H. Nomura ◽  
Y. Aikawa ◽  
Y. Nakagawa ◽  
T. J. Millar
Keyword(s):  
Chemical Structure ◽  
Protoplanetary Disks ◽  
Accretion Flow

Computer Simulation of Grain Growth in Polycrystalline Aggregates

1982 ◽  
Vol 21 ◽  
Author(s):  
M. P. Anderson ◽  
D. J. Srolovitz ◽  
G. S. Grest ◽  
P. S. Sahni
Keyword(s):  
Grain Growth ◽  
Chemical Properties ◽  
Predictive Ability ◽  
Grain Morphology ◽  
Catalytic Efficiency ◽  
Second Phase ◽  
Controllable Factors ◽  
Polycrystalline Aggregates ◽  
Grain Growth Kinetics ◽  
Physical And Chemical

The physical and chemical properties of materials are determined in part by microstructure. Grain orientation and size in polycrystalline aggregates affect, for example, yield strength, catalytic efficiency, chemisorption, physisorption, fracture and a host of other properties. The final grain morphology is often determined by thermal processing, addition of a second phase, deformation, etc. However, in order to effectively tailor the microstructure for specific applications, the mechanism and kinetics of grain growth must be known. Unfortunately, present theories predict grain growth kinetics (1–3) which often differ from experimental observation, have little predictive ability with respect to microstructure and are not easily generalized to account for experimentally controllable factors.

scholarly journals Analysis of oxidation degree of graphite oxide and chemical structure of corresponding reduced graphite oxide by selecting different-sized original graphite

RSC Advances ◽  
2018 ◽  
Vol 8 (31) ◽  
pp. 17209-17217 ◽  
Author(s):  
Lu Shen ◽  
Lihua Zhang ◽  
Kui Wang ◽  
Lijing Miao ◽  
Qiaofeng Lan ◽  
...  
Keyword(s):  
Graphite Oxide ◽  
Chemical Structure ◽  
Chemical Properties ◽  
Thermal Reduction ◽  
Physical And Chemical Properties ◽  
Oxidation Degree ◽  
Reduced Graphite Oxide ◽  
Physical And Chemical ◽  
And Chemical Properties

The thermal reduction of GO is the most commonly used strategy for preparation of rGO, and the oxidation degree of GO would influence the chemical structure of prepared rGO, thereby affecting its physical and chemical properties.

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