Ability of Naphthoquinondiazide Photoresists to Exothermic Decomposition

2020 ◽  
pp. 90-96
Author(s):  
A.N. Shushpanov ◽  
◽  
A.Ya. Vasin ◽  
V.M. Raykova ◽  
G.G. Gadzhiev ◽  
...  
Keyword(s):  
Convective Heat Exchange ◽  
Inert Atmosphere ◽  
Necessary Condition ◽  
Critical Temperatures ◽  
Good Convergence ◽  
Measuring Devices ◽  
Explosive Transformation ◽  
Exothermic Decomposition ◽  
Experimental Approaches ◽  
Experimental Values

The article considers two intermediate products of positive photoresists (1,2-naphthoquinonediazide-(2)-5-sulfonic acid of monosodium salt — Dye M and 1,2-naphthoquinonediazide-(2)-5-sulfochloride — Dye N2) from the standpoint of the tendency to explosive transformation. The experimental values of flash points determined on the OTP setup were 130 °C for Dye M and 95 °C for Dye N2. These values are close to the temperatures of the beginning of intensive exothermic decomposition (132 and 111 °C, respectively) obtained by thermogravimetric analysis. In addition, this analysis showed the presence of exothermic peaks in the studied samples both in the air and in an inert atmosphere of helium, which is a necessary condition for the manifestation of a tendency to explosive transformation. To confirm the possibility of explosive transformation, the flash points of substances were also determined by the calculation method according to the formula, which is a consequence of the problem of thermal explosion during convective heat exchange with the environment, and gave a result close to the experimental one (the values were 138 and 105 °C, respectively). For this calculation the following was used: the kinetic parameters determined by the Kissinger method, the values of the density of substances determined on an automatic pycnometer, as well as the values of the heat of explosive transformation obtained with the help of the Real computer thermodynamic program. The research results confirming the tendency of the investigated compounds to explosive transformation, as well as the critical temperatures, exceeding which is unacceptable, were transferred to the production of FGUP GNTs NIOPIK to create a safe technological process, safe storage and transportation conditions. Considering the accuracy of the measuring devices, the process temperature should not exceed 125 °C for Dye M and 90 °C for Dye N2. The conducted studies and calculations show that the computational and experimental approaches have good convergence, give values in a close temperature range, and increase the reliability of the obtained results.

Particle entropy and depairing in hot nuclei

2016 ◽  
Vol 25 (11) ◽  
pp. 1650093 ◽  
Author(s):  
J. Dhivya Saranya ◽  
N. Boomadevi ◽  
T. R. Rajasekaran
Keyword(s):  
Single Particle ◽  
Mass Region ◽  
Shell Closure ◽  
Critical Temperatures ◽  
Level Densities ◽  
Hot Nuclei ◽  
Pairing Correlations ◽  
Experimental Values ◽  
Low Entropy ◽  
Interesting Analogy

The nuclear level densities and single particle entropies are predicted for nuclei in the mass region [Formula: see text] within a framework of statistical theory of hot nuclei method. In this method, particle-number and energy conservation as well as nuclear pairing correlations are included in the partition function of grand canonical ensemble. The suppression of pairing correlations is distinctly noticed in temperature dependence of entropies between the critical temperatures [Formula: see text] MeV and [Formula: see text] MeV for [Formula: see text], [Formula: see text] and [Formula: see text] isotopes of the elements. These structural thermodynamic entropies are interpreted as a remarkable signature of the superfluid to normal phase transition connected to the vanishing of pairing gap. The calculated level densities are compared with recent experimental values. In addition, the single particle entropy of intermediate-mass nuclei is depicted as half of the entropy of mid-shell nuclei in the rare-earth region. As a consequence, the [Formula: see text] shell closure of [Formula: see text]V carries low entropy at low excitation energy presents an interesting analogy to the [Formula: see text] shell closure of [Formula: see text]Ni. Merely, in the case of odd–even [Formula: see text] has higher entropy than the even–even [Formula: see text] nucleus.

THEORETICAL ASPECTS OF THE FIELD INDUCED SUPERCONDUCTIVITY IN POLYACENES AND C60

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1547-1551
Author(s):  
S.-L. DRECHSLER ◽  
G. PAASCH ◽  
J. MÁLEK ◽  
S. V. SHULGA ◽  
H. ESCHRIG ◽  
...  
Keyword(s):  
Tight Binding ◽  
Band Structure Calculation ◽  
Full Potential ◽  
Coupling Constant ◽  
Phonon Coupling ◽  
Critical Temperatures ◽  
Binding Model ◽  
Electron Phonon Coupling ◽  
Strong Coulomb ◽  
Experimental Values

The electronic structure and the superconductivity in field-doped polyacenes are considered. Within a modified Thomas–Fermi approach for typical experimental values of the surface charge density the injected charge is confined to a monolayer. The electron–phonon coupling constant for internal modes λintra is estimated using the work of Devos and Lanoo (Ref. 4) and the density of states N(0) estimated from a 2D tight-binding model derived from a full potential LDA band structure calculation for bulk anthracene. The empirical values of the Coulomb pseudopotentials are significantly enhanced. The strong Coulomb interaction is considered as a key quantity which determines the large differences in the critical temperatures achieved for n-doped polyacenes and C 60.

scholarly journals The effect of testing procedure on DSC measurements of Gd-Ti-Zr alloy using ZrO2 container

2020 ◽  
pp. 27-27
Author(s):  
P. Turalska ◽  
M. Homa ◽  
N. Sobczak ◽  
A. Gazda ◽  
A. Wierzbicka-Miernik ◽  
...  
Keyword(s):  
Testing Procedure ◽  
Product Layer ◽  
Molten Alloy ◽  
Scanning Calorimetry ◽  
Critical Temperatures ◽  
Testing Procedures ◽  
Dsc Measurements ◽  
Measuring Devices ◽  
Temperature Interaction ◽  
Dsc Method

Differential Scanning Calorimetry (DSC) was applied to determine the critical temperatures of phase transformations in the Gd40Ti30Zr30 alloy (wt%). The comparative measurements were carried out using three types of measuring devices at a temperature RT- 1650?C in the same flowing gas (Ar, 99.9992%) but applying different testing procedures, which allowed obtaining dissimilar oxygen contents in the surrounding atmosphere. The high temperature interaction and reactivity taking place between molten alloy samples and ZrO2 container during DSC tests were evaluated by structural analysis of the resulting interfaces using alloy samples solidified inside the ZrO2 containers. The conducted research has demonstrated methodological difficulties accompanying measurements of the thermophysical properties of Gd-rich alloys by the container-assisted DSC method, particularly when the tests are performed in flowing argon atmosphere with significantly reduced oxygen content. Under non-oxidizing conditions, the degradation of ZrO2 container can take place during DSC testing because the selected Gd40Ti30Zr30 alloy reacts with the ZrO2 to form a continuous interfacial reaction product layer. Under slightly oxidizing conditions, the gadolinium oxide formed in situ on the alloy surface, plays the role of a barrier for direct contact between molten alloy and container and thus may suppress or even prevent the degradation of the container and its subsequent strong bonding with the holder.

Empirical Regularities in the Behaviour of the Critical Constants of Fluid Alkali Metals

2000 ◽  
Vol 214 (6) ◽  
Author(s):  
F. Hensel ◽  
G.F. Hohl ◽  
D. Schaumlöffel ◽  
W.-C. Pilgrim ◽  
Ernst Ulrich Franck
Keyword(s):  
Alkali Metals ◽  
Coexistence Curve ◽  
Reduced Form ◽  
Critical Temperatures ◽  
Empirical Regularities ◽  
Experimental Values ◽  
Critical Constants

We report new measurements of the densities of the coexisting liquid and vapour phases of the alkali metals K and Na. Comparison of the coexistence curve of K with those of Cs and Rb in reduced form shows that the alkali metals behave very similarly close to the critical temperatures. The experimental values of the critical constants T

Theoretical and experimental approaches to the barrier to rotation about the Csp2—Csp3 bond in benzyl silane. Hyperconjugative stabilization of the perpendicular conformation

1991 ◽  
Vol 69 (3) ◽  
pp. 496-502 ◽  
Author(s):  
Ted Schaefer ◽  
Rudy Sebastian ◽  
Glenn H. Penner
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Key Words ◽  
Long Range ◽  
Electron System ◽  
Coupling Constants ◽  
Mo Calculations ◽  
Nuclear Magnetic Resonance Spectra ◽  
Experimental Approaches ◽  
Experimental Values

The 1H nuclear magnetic resonance spectra of benzyl silane and benzyl trichlorosilane, obtained in CS2 and benzene-d6 solutions, are analyzed. The long-range coupling constants between the methylene and para ring protons are used to derive apparent twofold barriers about the Csp2—Csp3 bonds of 7.4 ± 1.6 and 8.1 ± 1.1 kJ/mol for the silane and the trichlorosilane, respectively. These are higher than that for ethylbenzene and are attributed mainly to the stabilization of the perpendicular conformer, that with the C—Si bond in a plane perpendicular to the phenyl plane, by σ–π conjugation (hyperconjugation) of the C—Si bond and the π electron system. Molecular orbital computations confirm the predominantly twofold nature of the internal barrier in benzyl silane and also for benzyl germane and stannane. The calculated barriers for the silane derivatives are rather higher than the experimental values. The computed barriers have magnitudes that appear to change with X in much the same order as do the hyperconjugative interactions deduced in other ways for CH2X(CH3)3 groups (X = Sn, Ge, Si, C). The angles CCX in benzyl-X (X = CH3, SiH3, SiCl3, GeH3, SnH3) are all computed to decrease smoothly as sin2ψ, where ψ is the angle by which the C—X bond twists out of the phenyl plane. Key words: conformations, benzyl silane and trichlorosilane; NMR, benzyl silane and trichlorosilane; MO calculations, benzyl silane and trichlorosilane.

scholarly journals Unified understanding of superconductivity and Mott transition in alkali-doped fullerides from first principles

2015 ◽  
Vol 1 (7) ◽  
pp. e1500568 ◽  
Author(s):  
Yusuke Nomura ◽  
Shiro Sakai ◽  
Massimo Capone ◽  
Ryotaro Arita
Keyword(s):  
Phase Diagram ◽  
First Principles ◽  
A Priori ◽  
Critical Temperatures ◽  
Experimental Phase Diagram ◽  
Many Body Theory ◽  
Jahn Teller ◽  
Priori Information ◽  
Experimental Values ◽  
Insulating Phase

Alkali-doped fulleridesA3C60(A= K, Rb, Cs) are surprising materials where conventional phonon-mediated superconductivity and unconventional Mott physics meet, leading to a remarkable phase diagram as a function of volume per C60molecule. We address these materials with a state-of-the-art calculation, where we construct a realistic low-energy model from first principles without using a priori information other than the crystal structure and solve it with an accurate many-body theory. Remarkably, our scheme comprehensively reproduces the experimental phase diagram including the low-spin Mott-insulating phase next to the superconducting phase. More remarkably, the critical temperaturesTc’s calculated from first principles quantitatively reproduce the experimental values. The driving force behind the surprising phase diagram ofA3C60is a subtle competition between Hund’s coupling and Jahn-Teller phonons, which leads to an effectively inverted Hund’s coupling. Our results establish that the fullerides are the first members of a novel class of molecular superconductors in which the multiorbital electronic correlations and phonons cooperate to reach highTcs-wave superconductivity.

A simple method for estimating vaporization properties of pheromone-like acetates from their molecular structures

1991 ◽  
Vol 56 (4) ◽  
pp. 727-735 ◽  
Author(s):  
Bohumír Koutek ◽  
Michal Hoskovec ◽  
Jan Vrkoč
Keyword(s):  
Close Correlation ◽  
Molecular Structures ◽  
Computational Method ◽  
Vapor Pressures ◽  
Critical Temperatures ◽  
Simple Method ◽  
Evaporative Loss ◽  
Group Contribution Methods ◽  
Experimental Values ◽  
Comparison Of The Results

A simple computational method has been developed to determine vapor pressures of pheromone-like acetates, This input parameters required, i.e. critical temperatures and critical pressures are obtained from the known molecular structures by using group contribution methods. Subsequently, the vapor pressures are estimated by the three parameter corresponding states equation of Lee and Kesler. The validity of this approach was tested on a homogeneous experimental material (eleven C10 to C16 acetates) by standard methods of statistical analysis, as well as by comparison of the results with corresponding experimental data. When compared with GC based experimental values, the estimated vapor pressures show mean relative error ±10%, achieving thus a better accuracy than other experimental methods when compared among themselves. A close correlation, viz. In t1/2 = -0.294 In P + 1.82 (r = 0.9986) has been found between first order half-lives for evaporative loss of acetates from rubber septa and calculated vapor pressures.

SF6− photodetachment near the adiabatic limit

2015 ◽  
Vol 17 (12) ◽  
pp. 7670-7675 ◽  
Author(s):  
I. Luzon ◽  
M. Nagler ◽  
O. Heber ◽  
D. Strasser
Keyword(s):  
Cross Section ◽  
High Sensitivity ◽  
Adiabatic Limit ◽  
Experimental Approaches ◽  
Photodetachment Cross Section ◽  
Experimental Values

High sensitivity photodetachment cross-section measurements suggest a SF6− adiabatic detachment energy of 1.7 ± 0.02 eV, significantly higher than previously recommended experimental values. Possible differences between the experimental approaches are discussed.

scholarly journals Oil additive and its effect

2013 ◽  
Vol 61 (3) ◽  
pp. 691-697 ◽  
Author(s):  
Vojtěch Kumbár ◽  
Petr Dostál
Keyword(s):  
Mathematical Model ◽  
Chemical Elements ◽  
Viscosity Index ◽  
Engine Oil ◽  
Engine Oils ◽  
Experimental Approaches ◽  
Experimental Values ◽  
Rotary Viscometer ◽  
Oil Particles

The aim of this paper are experimental approaches, selected for analysis of the engine oils and described above, are surely sufficient for the needs of presented research. The spectrometry was used for determination of presence of selected chemical elements and especially metals in oil. Particles monitoring was employed in order to describe the amount, type, and size of friction particles. The temperature dependence of dynamic viscosity was evaluated by use of rotary viscometer. In case of all three approaches it is advantageous to compare the measured values with the results received for unused engine oil of the same marking and viscosity index. If the degradation of oil is classified as low or medium, it is possible to increase its service life for several thousands of kilometers. Mathematical model (polynomial 6thdegree) it was used for fitting experimental values.

The Infancy of Solar-Type Stars and its Relevance for the Origin of Life

1997 ◽  
Vol 161 ◽  
pp. 267-282 ◽  
Author(s):  
Thierry Montmerle
Keyword(s):  
Main Sequence ◽  
Solar Nebula ◽  
Circumstellar Disks ◽  
T Tauri Stars ◽  
Necessary Condition ◽  
Sequence Evolution ◽  
T Tauri ◽  
Solar Type ◽  
Optical Domain ◽  
The Origin Of Life

AbstractFor life to develop, planets are a necessary condition. Likewise, for planets to form, stars must be surrounded by circumstellar disks, at least some time during their pre-main sequence evolution. Much progress has been made recently in the study of young solar-like stars. In the optical domain, these stars are known as «T Tauri stars». A significant number show IR excess, and other phenomena indirectly suggesting the presence of circumstellar disks. The current wisdom is that there is an evolutionary sequence from protostars to T Tauri stars. This sequence is characterized by the initial presence of disks, with lifetimes ~ 1-10 Myr after the intial collapse of a dense envelope having given birth to a star. While they are present, about 30% of the disks have masses larger than the minimum solar nebula. Their disappearance may correspond to the growth of dust grains, followed by planetesimal and planet formation, but this is not yet demonstrated.

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