scholarly journals Substituent effect on the thermophysical properties and thermal dissociation behaviour of 9-substituted anthracene derivatives

2021 ◽  
Author(s):  
Joost Brancart ◽  
Jonas Van Damme ◽  
Filip Du Prez ◽  
Guy Van Assche
Keyword(s):  
Thermophysical Properties ◽  
Substituent Effect ◽  
Chemical Structure ◽  
Thermal Dissociation ◽  
Aromatic System ◽  
Electron Balance ◽  
Anthracene Derivatives

The chemical structure and location of substituents on anthracene derivatives influence the electron balance of the aromatic system, thus determining the wavelengths at which light is absorbed, which results in...

Rifamide (rifocin-M)

1968 ◽  
Vol 6 (22) ◽  
pp. 86-88 ◽  
Keyword(s):  
Rna Polymerase ◽  
Chemical Structure ◽  
Crystalline Form ◽  
Clinical Use ◽  
Aromatic System ◽  
Rifamycin Sv ◽  
Bacterial Rna ◽  
Aliphatic Bridge ◽  
Rifamycin B

The rifamycins are antibiotics derived from Streptomyces mediterranei.1 Their chemical structure is novel, with a long aliphatic bridge spanning an aromatic system. They act by inhibiting bacterial RNA polymerase, as do the actinomycins. Of the five compounds originally isolated, only rifamycin B was obtained in stable crystalline form, and three substances derived from this have come into clinical use: rifamycin SV, 2 rifampicin,3 and rifamycin B-diethylamide or rifamide (Rifocin-M - Lepetit).4

Thermal Properties of Magnetron Sputtered TiN And TiAlN Thin Films on HSS

1996 ◽  
Vol 436 ◽  
Author(s):  
E. Lugscheider ◽  
O. Knotek ◽  
C. Barimani ◽  
H. Zimmermann ◽  
M. Lake
Keyword(s):  
Thermophysical Properties ◽  
High Speed ◽  
Chemical Structure ◽  
Chemical Resistance ◽  
Cutting Tools ◽  
Measuring System ◽  
Small Scale ◽  
Thermal Barrier ◽  
Pvd Coatings ◽  
Pin On Disc

AbstractIncreasing demands on production processes in terms of performance, reliability and environmental compatibility shape the specification profile for modem wear resistant coating systems. The specification of PVD coated cutting tools by the parameters hardness, wear and frictional behavior, chemical structure or chemical resistance are already known and inspected by small scale tests, e.g. pin on disc or taber abraser test. Hitherto the thermophysical properties of thin film PVD coatings were not characterized completely although the investigation of the thermal diffusivity of coated substrates give information about the thermal barrier function of the deposited coating.To determine the thermophysical properties of PVD coatings the Jenoptik Thermal Wave Inspection (TWIN) can be used. This nondestructive and contactless measuring system is based on the photothermal spectroscopy. In this paper fundamentals of the TWIN measuring technique are presented as well as first TWIN results of investigated MSIP TiN and TiAlN coated and oxidized high speed steels.

Correlation between thermal dissociation and chemical structure of blocked isocyanates

1993 ◽  
Vol 22 (1-4) ◽  
pp. 279-286 ◽  
Author(s):  
Ichiro Muramatsu ◽  
Yoichi Tanimoto ◽  
Mitsuo Kase ◽  
Noboru Okoshi
Keyword(s):  
Chemical Structure ◽  
Thermal Dissociation

The substituent effect on charge transport property of triisopropylsilylethynyl anthracene derivatives

2014 ◽  
Vol 15 (10) ◽  
pp. 2476-2485 ◽  
Author(s):  
Lijuan Wang ◽  
Ping Li ◽  
Bin Xu ◽  
Houyu Zhang ◽  
Wenjing Tian
Keyword(s):  
Charge Transport ◽  
Transport Property ◽  
Substituent Effect ◽  
Charge Transport Property ◽  
Anthracene Derivatives

Studies of the Substituent Effect in Aromatic Systems by Chlorine Nuclear Quadrupole Resonance (35Cl-NQR). Chloroanilinium Salts, [ClxC6Η5-xΝΗ3⊕]Χ⊖ with X⊖. =Cl⊖, Br⊖, etc.

1971 ◽  
Vol 26 (6) ◽  
pp. 555-560 ◽  
Author(s):  
W. Pies ◽  
Alarich Weiss
Keyword(s):  
Nuclear Quadrupole Resonance ◽  
Charge Distribution ◽  
Benzene Ring ◽  
Substituent Effect ◽  
Aromatic System ◽  
Quadrupole Resonance ◽  
35Cl Nqr ◽  
Aromatic Systems ◽  
Nuclear Quadrupole ◽  
Substituent Influence

The 35Cl-NQR spectra of 27 chloroanilinium salts, [ClxC6H5-xNH3⊕] X⊖, mainly chlorides and bromides, were investigated at 77 °K. The 35Cl-NQR frequencies were tentatively assigned to certain chlorine atoms at the benzene ring. The substituent influence of the — NH3⊕X⊖ group is discussed in terms of the NQR substituent parameter x. The electron attracting power of this group is clearly revealed. It decreases in the order ortho > meta > para of the substitution at the benzene ring with regard to the chlorine position. The substituent parameters x and σ(Hammett) are compared for the —NH3⊕X⊖ group and the — NH2 group. The anion in the anilinium salts, Xe, seems to have no influence on the charge distribution within the aromatic system.

scholarly journals EQUATIONS OF AVERAGE ISOBARIC HEAT CAPACITY OF AIR AND COMBUSTION GASES WITH INFLUENCE OF PRESSURE AND EFFECT OF THERMAL DISSOCIATION

2019 ◽  
pp. 18-29
Author(s):  
Maya Vladimirovna Ambrozhevich ◽  
Mikhail Anatol'evich Shevchenko
Keyword(s):  
Heat Capacity ◽  
Thermophysical Properties ◽  
Thermal Dissociation ◽  
Heat Capacities ◽  
Isobaric Heat Capacity ◽  
Information Storage ◽  
Working Fluid ◽  
Saturation Curve ◽  
Functional Dependencies ◽  
Temperature And Pressure

All properties of thermomechanical systems working substance are two-parameter that is determined by two parameters, the most often they are temperature and pressure which are easily measured by experiment. Representing the isobaric heat capacity as a function of temperature cp = f(T) become a thing of the past. Analytical and tabular ways are used to represent dependencies as a function of temperature and pressure. The tabular method is convenient for single calculations, but the analytical one is more convenient for a series of calculations. The advantages of an analytical description in comparison with a tabular one are obvious, namely, compactness of information storage without reference to node points, the ability to integrate and differentiate, dependencies can be embedded directly in the program body and don’t require special subroutines to access to the tables. Developers of the programs for calculating thermophysical properties, as a rule, use functional dependencies which may have a different appearance for temperature and pressure intervals of the same substance. This is explained by the fact that in the region close to the saturation curve, there is a steep change in all the thermophysical properties of substances including the isobaric heat capacity. In thermogasdynamic calculations of heat machines, the main physical parameter of the working fluid is its heat capacity, both true and average. The article presents the analytical dependencies of the average specific isobaric heat capacities of the main components of air and combustion products of hydrocarbon fuels which are united throughout the specified range of pressures and temperatures (nitrogen: p = 1 ... 200 bar, T = 150 ... 2870 K, oxygen: p = 1 ... 200 bar, T = 210 ... 2870 K, argon: p = 1 ... 200 bar, T = 190 ... 1300 K, the water vapor: p = 0,1 ... 200 bar, T = 700 ... 2600 K, carbon dioxide: p = 1 ... 200 bar, T = 390 ... 2600 K). The analytical dependencies were derived on the basis of previously obtained analytical expressions for the specific isobaric heat capacities of these gases. The average specific isobaric heat capacities of gases are also functions of temperature and pressure cp = f(T, P) and take into account the effect of thermal dissociation. Formulas for average specific isobaric heat capacities are obtained by integrating expressions for specific isobaric heat capacities. Verification of the obtained dependencies for different temperature ranges was done.

scholarly journals Densities and Viscosities of Ionic Liquid with Organic Solvents

2020 ◽  
Vol 10 (23) ◽  
pp. 8342
Author(s):  
Fuxin Yang ◽  
Peng Feng
Keyword(s):  
Ionic Liquid ◽  
Thermophysical Properties ◽  
Atmospheric Pressure ◽  
Chemical Structure ◽  
Excess Molar Volumes ◽  
High Viscosity ◽  
Chemical Processes ◽  
Capillary Viscometer ◽  
Hard Sphere Model ◽  
Derived Properties

The ionic liquid (IL) of 1-hexyl-3-methylimidazolium acetate is widely used in chemical and bio-chemical processes. In this work, due to the high viscosity of IL, the promising chemicals (i.e., N, N-dimethylacetamide, N, N-dimethylformamide, and dimethyl sulfoxide) were selected as the additives to lower IL viscosity. The thermophysical properties of density and viscosity for IL with solvents were measured using a digital vibrating U-tube densimeter and an Ubbelohde capillary viscometer from 303.15 to 338.15 K at atmospheric pressure (0.0967 MPa), respectively. The influences of the solvents on the thermophysical properties of ionic liquid were quantitatively studied. Furthermore, based on the measurement values, the derived properties of excess molar volumes, thermal expansion coefficient, and the energy barrier were calculated, and the results showed that the mixture composition had great impact on excess volume change and viscosity. The hard-sphere model was employed to reproduce the viscosity. The infrared spectroscopy was performed to study the chemical structure to further understand the interactions between IL and the solvents.

Erratum to “Correlation between thermal dissociation and chemical structure of blocked isocyanates”

1999 ◽  
Vol 37 (3-4) ◽  
pp. 205 ◽  
Author(s):  
Ichiro Muramatsu ◽  
Yoichi Tanimoto ◽  
Mitsuo Kase ◽  
Noboru Okoshi
Keyword(s):  
Chemical Structure ◽  
Thermal Dissociation

Inelastic Electron-Matter Interactions

1978 ◽  
Vol 36 (3) ◽  
pp. 259-267
Author(s):  
J. Silcox
Keyword(s):  
Electron Microscope ◽  
Energy Loss ◽  
Chemical Structure ◽  
Inelastic Electron ◽  
Primary Concern ◽  
Unique Probe ◽  
Introductory Paper ◽  
Elastic Processes ◽  
Experimental Level ◽  
Inelastic Processes

In this introductory paper, my primary concern will be in identifying and outlining the various types of inelastic processes resulting from the interaction of electrons with matter. Elastic processes are understood reasonably well at the present experimental level and can be regarded as giving information on spatial arrangements. We need not consider them here. Inelastic processes do contain information of considerable value which reflect the electronic and chemical structure of the sample. In combination with the spatial resolution of the electron microscope, a unique probe of materials is finally emerging (Hillier 1943, Watanabe 1955, Castaing and Henri 1962, Crewe 1966, Wittry, Ferrier and Cosslett 1969, Isaacson and Johnson 1975, Egerton, Rossouw and Whelan 1976, Kokubo and Iwatsuki 1976, Colliex, Cosslett, Leapman and Trebbia 1977). We first review some scattering terminology by way of background and to identify some of the more interesting and significant features of energy loss electrons and then go on to discuss examples of studies of the type of phenomena encountered. Finally we will comment on some of the experimental factors encountered.

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