Anomalous thermal conductance of graphyne under lower temperature

2017 ◽  
Vol 29 (45) ◽  
pp. 455702 ◽  
Author(s):  
Xue-Kun Chen ◽  
Jun Liu ◽  
Dan Du ◽  
Ke-Qiu Chen
Keyword(s):  
Thermal Conductance ◽  
Lower Temperature

Silicon Tetrachloride Synthesis from Rice Hulls: Transmission and Scanning Electron Microscope Study

1972 ◽  
Vol 30 ◽  
pp. 236-237 ◽  
Author(s):  
Richard S. Thomas ◽  
Prabir K. Basu ◽  
Francis T. Jones
Keyword(s):  
Silicon Tetrachloride ◽  
Silica Sand ◽  
Mineral Matter ◽  
Chemical Heterogeneity ◽  
Scanning Electron Microscope Study ◽  
Rice Hulls ◽  
Hull Structure ◽  
Lower Temperature ◽  
Image Position ◽  
Disposal Problem

Silicon tetrachloride, used in industry for the production of highest purity silicon and silica, is customarily manufactured from silica-sand and charcoal.SiCl4 can also be made from rice hulls, which contain up to 20 percent silica and only traces of other mineral matter. Hulls, after carbonization, actually prove superior as a starting material since they react at lower temperature. This use of rice hulls may offer a new, profitable solution for a rice mill byproduct disposal problem.In studies of the reaction kinetics with carbonized hulls, conversion of SiO2 to SiCl4 was found to proceed within a few minutes to a constant, limited yield which depended reproducibly on the ambient temperature of the reactor. See Fig. 1. This suggested that physical or chemical heterogeneity of the silica in the hull structure might be involved.

Surface energy of cellulosic materials: The effect of particle morphology, particle size, and hydroxyl number

TAPPI Journal ◽  
2015 ◽  
Vol 14 (9) ◽  
pp. 565-576 ◽  
Author(s):  
YUCHENG PENG ◽  
DOUGLAS J. GARDNER
Keyword(s):  
Particle Size ◽  
Surface Energy ◽  
Particle Morphology ◽  
Nanofibrillated Cellulose ◽  
Particle Sizes ◽  
Hydroxyl Number ◽  
Small Individual ◽  
Dispersion Component ◽  
Commercial Applications ◽  
Lower Temperature

Understanding the surface properties of cellulose materials is important for proper commercial applications. The effect of particle size, particle morphology, and hydroxyl number on the surface energy of three microcrystalline cellulose (MCC) preparations and one nanofibrillated cellulose (NFC) preparation were investigated using inverse gas chromatography at column temperatures ranging from 30ºC to 60ºC. The mean particle sizes for the three MCC samples and the NFC sample were 120.1, 62.3, 13.9, and 9.3 μm. The corresponding dispersion components of surface energy at 30°C were 55.7 ± 0.1, 59.7 ± 1.3, 71.7 ± 1.0, and 57.4 ± 0.3 mJ/m2. MCC samples are agglomerates of small individual cellulose particles. The different particle sizes and morphologies of the three MCC samples resulted in various hydroxyl numbers, which in turn affected their dispersion component of surface energy. Cellulose samples exhibiting a higher hydroxyl number have a higher dispersion component of surface energy. The dispersion component of surface energy of all the cellulose samples decreased linearly with increasing temperature. MCC samples with larger agglomerates had a lower temperature coefficient of dispersion component of surface energy.

Formation of Nanocrystalline Silicon in Tin-Doped Amorphous Silicon Films

2020 ◽  
Vol 65 (3) ◽  
pp. 236
Author(s):  
R. M. Rudenko ◽  
O. O. Voitsihovska ◽  
V. V. Voitovych ◽  
M. M. Kras’ko ◽  
A. G. Kolosyuk ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Crystalline Silicon ◽  
Solid Phase ◽  
Nanocrystalline Silicon ◽  
Recrystallization Temperature ◽  
Nanocrystalline Phase ◽  
Silicon Phase ◽  
Silicon Nanocrystallites ◽  
Lower Temperature ◽  
Two Stages

The process of crystalline silicon phase formation in tin-doped amorphous silicon (a-SiSn) films has been studied. The inclusions of metallic tin are shown to play a key role in the crystallization of researched a-SiSn specimens with Sn contents of 1–10 at% at temperatures of 300–500 ∘C. The crystallization process can conditionally be divided into two stages. At the first stage, the formation of metallic tin inclusions occurs in the bulk of as-precipitated films owing to the diffusion of tin atoms in the amorphous silicon matrix. At the second stage, the formation of the nanocrystalline phase of silicon occurs as a result of the motion of silicon atoms from the amorphous phase to the crystalline one through the formed metallic tin inclusions. The presence of the latter ensures the formation of silicon crystallites at a much lower temperature than the solid-phase recrystallization temperature (about 750 ∘C). A possibility for a relation to exist between the sizes of growing silicon nanocrystallites and metallic tin inclusions favoring the formation of nanocrystallites has been analyzed.

THERMAL CONDUCTANCE OF TWO-SIDED CNT INTERFACES MEASUERED BY A PHOTO ACOUSTIC TECHNIQUE

Equipment ◽  
2006 ◽  
Author(s):  
B. A. Cola ◽  
J. Xu ◽  
C. Cheng ◽  
Xianfan Xu ◽  
T. Fisher
Keyword(s):  
Thermal Conductance ◽  
Acoustic Technique

Quality indicators of the spontaneous fermentation starters of cereals flour during the lower-temperature conservation process

2018 ◽  
Vol 6 (11) ◽  
pp. 116-122
Author(s):  
Larysa Mikhonik ◽  
◽  
Inna Getman ◽  
Natalia Bela ◽  
Halyna Bogdan ◽  
...  
Keyword(s):  
Quality Indicators ◽  
Spontaneous Fermentation ◽  
Lower Temperature ◽  
Fermentation Starters

Thermoelectric properties of B12N12 molecule

2019 ◽  
Vol 16 ◽  
Author(s):  
Mohammad Reza Niazian ◽  
Laleh Farhang Matin ◽  
Mojtaba Yaghobi ◽  
Amir Ali Masoudi
Keyword(s):  
Molecular Electronics ◽  
Thermoelectric Properties ◽  
Electronic Devices ◽  
Thermal Conductance ◽  
Wide Band ◽  
Oscillatory Behavior ◽  
Mapping Technique ◽  
Junction Points ◽  
Inelastic Behaviour ◽  
New Generation

Background: Recently, molecular electronics have attracted the attention of many researchers, both theoretically and applied electronics.Nanostructures have significant thermal properties, which is why they are considered as good options for designing a new generation of integrated electronic devices. Objective: In this paper, the focus is on the thermoelectric properties of the molecular junction points with the electrodes. Also, the influence of the number of atom contacts was investigated on the thermoelectric properties of molecule located between two electrodes metallic.Therefore, the thermoelectric characteristics of the B12 N12 molecule are investigated. Methods: For this purpose, the Green’s function theory as well as mapping technique approach with the wide-band approximation and also the inelastic behaviour is considered for the electron-phonon interactions. Results & Conclusion: Results & Conclusion:It is observed that the largest values of the total part of conductance as well as its elastic (G(e,n)max) depends on the number of atom contacts and are arranged as: G(e,1)max>G(e,4)max>G(e,6)max. Furthermore, the largest values of the electronic thermal conductance, i.e. Kpmax is seen to be in the order of K(p,4)max < K(p,1)max < K(p,6)max that the number of main peaks increases in four-atom contacts at (E<Ef). Furthermore, it is represented that the thermal conductance shows an oscillatory behavior which is significantly affected by the number of atom contacts.

The Binding and Viscometric Studies of Ni+2, Co+2 and Mn+2 Ions with Protein by Spectrometric and pH Metric Techniques

2019 ◽  
Vol 9 (2) ◽  
pp. 151-162
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Protein Molecule ◽  
Vital Role ◽  
Sufficient Evidence ◽  
Structural Requirement ◽  
Nickel Ions ◽  
Cobalt Ions ◽  
Lower Temperature ◽  
Specific Oxidation

Background: The metal ions play a vital role in a large number of widely differing biological processes. Some of these processes are quite specific in their metal ion requirements. In that only certain metal ions, in specific oxidation states, can full fill the necessary catalytic or structural requirement, while other processes are much less specific. Objective: In this paper we report the binding of Mn (II), Ni (II) and Co (II) with albumin are reported employing spectrophotometric and pH metric method. In order to distinguish between ionic and colloidal linking, the binding of metal by using pH metric and viscometric methods and the result are discussed in terms of electrovalent and coordinate bonding. Methods: The binding of Ni+2, Co+2 and Mn+2 ions have been studied with egg protein at different pH values and temperatures by the spectrometric technique. Results: The binding data were found to be pH and temperature dependent. The intrinsic association constants (k) and the number of binding sites (n) were calculated from Scatchard plots and found to be at the maximum at lower pH and at lower temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with these metal ions. Statistical effects seem to be more significant at lower Ni+2, Co+2 and Mn+2 ions concentrations, while at higher concentrations electrostatic effects and heterogeneity of sites are more significant. Conclusion: The pH metric as well as viscometric data provided sufficient evidence about the linking of cobalt, nickel and manganese ions with the nitrogen groups of albumin. From the nature and height of curves in the three cases it may be concluded that nickel ions bound strongly while the cobalt ions bound weakly.

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