Static dielectric constants of water + ethanol and water + 2-methyl-2-propanol mixtures from 0.1 to 300 MPa at 298.15 K

1990 ◽  
Vol 35 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Takashi Moriyoshi ◽  
Tetsuro Ishii ◽  
Yoshihisa Tamai ◽  
Masafumi Tado
Keyword(s):  
Dielectric Constants ◽  
Static Dielectric Constants

Static dielectric constants of the N,N-dimethylformamide/2-methoxyethanol solvent system at various temperatures

1992 ◽  
Vol 70 (12) ◽  
pp. 2895-2899 ◽  
Author(s):  
Fulvio Corradini ◽  
Luigi Marcheselli ◽  
Lorenzo Tassi ◽  
Giuseppe Tosi
Keyword(s):  
Liquid State ◽  
Specific Interaction ◽  
Solvent System ◽  
Liquid Mixtures ◽  
Dielectric Constants ◽  
Empirical Equations ◽  
Binary Liquid ◽  
Fraction Mixture ◽  
Static Dielectric Constants ◽  
Formation Of Complexes

Measurements of static dielectric constants (ε) have been made for binary liquid mixtures of N,N-dimethylformamide (DMF)/2-methoxyethanol (ME) at 19 temperatures ranging from −10 to +80 °C. Some empirical equations of the type ε = ε(T), ε = ε(X1), and ε = ε(T,X1) have been applied to check their validity. The εE values, which refer to the deviation of the dielectric constants of the binaries from the values arising from mole fraction mixture law, have been calculated. Deviations from ideal behaviour have been found to be positive at all temperatures. The positive εE values are attributed to a specific interaction between unlike molecules, which leads to the formation of complexes between DMF and ME in the liquid state. These nDMF•mME complex moieties were found to have the stoichiometric ratios 2:1, 1:1, and 1:2 in the temperature range of −10 to +80 °C.

A first-principles study of the effects of different Al constituents on Ga1−xAlxN nanowires

2016 ◽  
Vol 30 (30) ◽  
pp. 1650217 ◽  
Author(s):  
Sihao Xia ◽  
Lei Liu ◽  
Yike Kong ◽  
Honggang Wang ◽  
Meishan Wang
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Plane Wave ◽  
First Principles ◽  
Formation Energy ◽  
High Energy ◽  
Dielectric Constants ◽  
Interesting Phenomenon ◽  
Densities Of States ◽  
Static Dielectric Constants

In order to investigate the influences of different Al constituents on Ga[Formula: see text]Al[Formula: see text]N nanowires, the formation energy, stability, band structure, densities of states and optical properties of Ga[Formula: see text]Al[Formula: see text]N nanowires with different Al constituents are calculated using first-principles plane-wave ultrasoft pseudopotential method. Results show that Ga[Formula: see text]Al[Formula: see text]N nanowires become more stable with increasing Al constituent. Bandgap of Ga[Formula: see text]Al[Formula: see text]N nanowires increases as the Al constituent increases but with a lower amplification compared with bulk Ga[Formula: see text]Al[Formula: see text]N. The peaks of static dielectric constants show a decreasing trend and move towards high-energy side as Al constituent increases. The absorption of Ga[Formula: see text]Al[Formula: see text]N nanowires shows an interesting phenomenon that it firstly increases and then decreases slightly as the Al constituent increases. Reflectivity of Ga[Formula: see text]Al[Formula: see text]N nanowires is much smaller than that of the bulk. The optical properties of Ga[Formula: see text]Al[Formula: see text]N nanowires show a blueshift effect as Al composition increases. According to these calculations, it is found that Ga[Formula: see text]Al[Formula: see text]N nanowires are appropriate to be applied into photoelectric detecting materials by adjusting the Al constituent of Ga[Formula: see text]Al[Formula: see text]N nanowires.

Hot model of muonium formation in liquids

2003 ◽  
Vol 81 (3) ◽  
pp. 199-203 ◽  
Author(s):  
David C Walker ◽  
Stefan Karolczak ◽  
Hugh A Gillis ◽  
Gerald B Porter
Keyword(s):  
Formation Mechanism ◽  
Full Range ◽  
Dielectric Constants ◽  
Published Data ◽  
Aprotic Solvents ◽  
Formation Model ◽  
Mechanism Of Formation ◽  
Muonium Formation ◽  
Static Dielectric Constants ◽  
Dipolar Aprotic Solvents

The mechanism of formation of muonium atoms from positive muons was studied here through measurements of the yield of diamagnetic muon states in dipolar aprotic solvents and for scavenger solutions in hexane and methanol. The results are compared with published data on common solvents covering a full range of the physicochemical properties of liquids that affect an ionic formation mechanism, namely their static dielectric constants, electron mobilities, and radiolysis yields of electrons. It is concluded that muonium is not formed by a thermal charge-neutralization reaction in these chemically-active media, though that mechanism does contribute to muonium formation in inert media like liquefied noble gases. It is clear that muonium materializes on a much shorter timescale than the recently proposed "delayed" mechanism (microseconds) and the earlier "spur" model (nanoseconds). In contrast, the data referring to all these liquids are consistent with the intra-track "hot" model. This is the only Mu-formation model proposed so far in which the immediate precursors of Mu (Mu(hot)) are neither scavengable nor ionic.Key words: muonium atoms, formation mechanism, hot model, spur model, delayed-muonium-formation model, diamagnetic yields.

scholarly journals Optical properties and electronic polarizability of boron-antimonide semiconductor

2017 ◽  
Vol 5 (2) ◽  
pp. 43 ◽  
Author(s):  
Salah Daoud ◽  
Abdelhakim Latreche
Keyword(s):  
Optical Properties ◽  
High Frequency ◽  
Theoretical Data ◽  
Dielectric Constants ◽  
Electronic Polarizability ◽  
Micro Hardness ◽  
Plasmon Energy ◽  
Empirical Formulas ◽  
Electronegativity Difference ◽  
Static Dielectric Constants

The high-frequency and static dielectric constants, the reflex index, the total optical electronegativity difference, the bulk modulus, the micro-hardness, the plasmon energy and the electronic polarizability of cubic zincblende boron-antimonide semiconductor have been estimated by using some empirical formulas. These parameters are analyzed by comparing them against the available experimental and theoretical data. In general, our obtained results agree well with other theoretical data from the literature.

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