Transient Phenomena in Dissociation of Diatomic Molecules

1971 ◽  
Vol 49 (22) ◽  
pp. 3744-3754 ◽  
Author(s):  
R. K. Boyd ◽  
George Burns
Keyword(s):  
Experimental Data ◽  
Chemical Reactions ◽  
Wide Temperature Range ◽  
Diatomic Molecules ◽  
The Other ◽  
Transient Phenomena ◽  
Temperature Range ◽  
Other Hand ◽  
Non Equilibrium

A model suitable for studies of non-equilibrium effects in chemical reactions (13) was used to predict incubation times for the dissociation of O2 in Ar between 2900 and 7200 °K. It was found that the model accounts satisfactorily for the experimental data. On the other hand previously used theories underestimate these incubation times by a factor of five to ten; the discrepancy is traced to assumptions used in previous investigations. When the same model is applied to the dissociation of Br2 in Ar and Cl2 in Ar, it correlates well a variety of experimental data, obtained over a wide temperature range.

The Interaction of Carbon Black with Sulfur, MBT and TMTD in Vulcanization

1961 ◽  
Vol 34 (2) ◽  
pp. 588-599 ◽  
Author(s):  
G. A. Blokh ◽  
Ch. L. Melamed
Keyword(s):  
Experimental Data ◽  
Carbon Black ◽  
Chemical Reactions ◽  
The Other ◽  
Considerable Importance ◽  
Physical Aspect ◽  
Active Centers ◽  
Other Hand ◽  
The One

Abstract The experimental data collected on the interaction of active centers of carbon black with the rubber on the one hand and of the active centers of carbon black with the sulfur and accelerators, and also with the antioxidants, on the other hand, provide a sound basis for belief that the problem of reinforcement of rubber by active fillers in the process of vulcanization cannot be explained from the physical aspect alone. The facts indicate the considerable importance of the chemical reactions between the active groups of carbon black and the compounding ingredients in the course of vulcanization.

The temperature-range of formation for tourmaline, rutile, brookite, and anatase in the Dartmoor granite

1927 ◽  
Vol 21 (116) ◽  
pp. 205-220 ◽  
Author(s):  
A. Brammall ◽  
H. F. Harwood
Keyword(s):  
Experimental Data ◽  
Igneous Rocks ◽  
The Other ◽  
Secondary Minerals ◽  
Temperature Range ◽  
Other Hand ◽  
The Status ◽  
Direct Separation

The range of temperature within which tourmaline can arise in nature has not hitherto been determined. No synthesis of this mineral is on record, and experimental data are therefore lacking. On the other hand, rutile, brookite, and anatase have all been prepared synthetically, and the experimental data suggest their rutile is formed at the highest temperatures, brookite at temperatures considerably lower, and anatase at a point still lower on the scale. It is generally conceded that for rutile a pyrogenic origin is possible, and that brookite and anatase appear only as secondary minerals. The status of tourmaline as a possible pyrogenic mineral is regarded as doubtful by Clarke, who states that' in igneous rocks tourmaline seems to have been produced by fumarole action, and not as a direct separation from the magma'.

About lung surgery

1903 ◽  
Vol 3 (9-10) ◽  
pp. 548-549
Author(s):  
E. Board
Keyword(s):  
Experimental Data ◽  
Lung Tissue ◽  
Lung Surgery ◽  
Operative Intervention ◽  
The Other ◽  
Pulmonary Diseases ◽  
Other Hand

Lung surgery is one of the youngest departments of surgical science. The basis for the development of methods of operative intervention in pulmonary diseases lies in the 1st possibility of preventing the danger of pneumothorax, which (danger) is currently so insignificant that some surgeons consider it even necessary to cause preliminary pneumothorax. On the other hand, the experimental data have shown the possibility of the loss of parts of the lung tissue and the conditions for the healing of its wounds.

scholarly journals The system CaO-MgO-FeO-SiO2 and its bearing on the origin of ultrabasic and basic rocks

1960 ◽  
Vol 32 (249) ◽  
pp. 459-470 ◽  
Author(s):  
Peter J. Wyllie
Keyword(s):  
Experimental Data ◽  
Temperature Interval ◽  
Wide Temperature Range ◽  
Multicomponent System ◽  
Small Temperature ◽  
Experimental Procedure ◽  
Temperature Range ◽  
A Value ◽  
Basaltic Magmas ◽  
Basic Rocks

SummaryExperimental data in the system CaO-MgO-FeO-SiO2 suggest that there may be a plateau on the liquidus and solidus of the multicomponent system basalt-peridotite. If this is so, fusion of peridotite would produce only basaltie magmas over a wide temperature range; when the temperature reached a value such that the liquid crossed the threshold of the plateau, there would be a rapid increase in the amount of fusion for small temperature increases, with the formation of picritic magmas; basaltic magmas containing suspended forsteritic olivine crystals could dissolve them if the temperature rose slightly above that of the plateau threshold; a high proportion of a picritic magma would crystallize in a small temperature interval, with the precipitation of forsteritic olivine that was only slightly zoned. These possibilities are compared with current theories, and it is concluded that several petrological axioms may require critical re-examination. An experimental procedure is outlined to determine the shape of the liquidus and solidus in the basalt-peridotite system.

scholarly journals Preparation and Thermal and Anti-UV Properties of Chitosan/Mica Copolymer

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Yih-Sheng Huang ◽  
Sheng-Haur Yu ◽  
Yea-Ru Sheu ◽  
Kuo-Shien Huang
Keyword(s):  
Experimental Data ◽  
Thermal Stability ◽  
Free Radical ◽  
Physical Properties ◽  
Ammonium Persulfate ◽  
Sodium Bisulfite ◽  
The Other ◽  
Other Hand

This experiment aims to produce a free radical while annoying the oxidizing-reducing reagent of the ammonium persulfate and the sodium bisulfite under nitrogen, then trigger copolymerization between modified-mica and chitosan to prepare a variety of copolymers. This experiment also aims to study the related properties of these copolymer materials. The experimental data shows that the copolymer has more thermal stability and better absorption of UV than chitosan. But the above physical properties will be less if the mica ratio in copolymer is more than 8%. On the other hand, the SEM photo of the microstructure also shows that the modified mica distributes homogeneously on the surface of the film of the copolymer.

Fuels Characterization for Use in Internal Combustion Engines

2001 ◽  
Author(s):  
R. Lanzafame ◽  
M. Messina
Keyword(s):  
Experimental Data ◽  
Wide Temperature Range ◽  
Internal Combustion Engines ◽  
Equilibrium Constants ◽  
Combustion Process ◽  
Internal Combustion ◽  
Least Square ◽  
Mathematical Functions ◽  
Temperature Range ◽  
Ic Engines

Abstract It is important provide mathematical functions able to fit with great precision experimental data on gases properties, in order to obtain reliable results when computerized models on IC engines are used. On the basis of experimental data on equilibrium constants (for dissociation phenomena occurring during combustion process in IC engines) new mathematical functions have been determined to fit experimental data. In comparison to traditional fitting polynomials, these new mathematical functions present a great accuracy in matching experimental data. These new mathematical functions have the functional forms of a V order Logarithmic Polynomial, and their coefficients have been evaluated on the basis of the least square method. The new V order Logarithmic Polynomials have been determined for several dissociation reactions according to internal combustion processes applications. V order Logarithmic Polynomials have been implemented also to describe the trend of specific heat at constant pressure Vs temperature and enthalpy Vs temperature. These new Logarithmic Polynomials have been calculated for several gases and fuels for IC engines applications. The new Logarithmic Polynomials pointed out a better precision in comparison to the others polynomial functions used in literature, and the possibility to utilize a single Logarithmic Polynomial for a wide temperature range, according to a good accuracy with experimental data. Another advantage of the Logarithmic Polynomials is the possibility to extrapolate experimental data on a wide temperature range (25% of experimental T range) in order to supply to the experimental data shortage.

scholarly journals Understanding the Interaction Modes and Reactivity of Trimedoxime toward MmAChE Inhibited by Nerve Agents: Theoretical and Experimental Aspects

2020 ◽  
Vol 21 (18) ◽  
pp. 6510
Author(s):  
Alexandre A. de Castro ◽  
Daniel A. Polisel ◽  
Bruna T. L. Pereira ◽  
Elaine F. F. da Cunha ◽  
Kamil Kuca ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mus Musculus ◽  
Active Site ◽  
Theoretical Calculations ◽  
Nerve Agents ◽  
The Other ◽  
Chemical Weapons ◽  
Reactivation Process ◽  
Other Hand

Organophosphorus (OP) compounds are used as both chemical weapons and pesticides. However, these agents are very dangerous and toxic to humans, animals, and the environment. Thus, investigations with reactivators have been deeply developed in order to design new antidotes with better efficiency, as well as a greater spectrum of action in the acetylcholinesterase (AChE) reactivation process. With that in mind, in this work, we investigated the behavior of trimedoxime toward the Mus musculus acetylcholinesterase (MmAChE) inhibited by a range of nerve agents, such as chemical weapons. From experimental assays, reactivation percentages were obtained for the reactivation of different AChE–OP complexes. On the other hand, theoretical calculations were performed to assess the differences in interaction modes and the reactivity of trimedoxime within the AChE active site. Comparing theoretical and experimental data, it is possible to notice that the oxime, in most cases, showed better reactivation percentages at higher concentrations, with the best result for the reactivation of the AChE–VX adduct. From this work, it was revealed that the mechanistic process contributes most to the oxime efficiency than the interaction in the site. In this way, this study is important to better understand the reactivation process through trimedoxime, contributing to the proposal of novel antidotes.

A Hybrid Semi-empirical Model for Lean Blow-Out Limit Predictions of Aero-engine Combustors

2014 ◽  
Vol 137 (3) ◽  
Author(s):  
Bin Hu ◽  
Yong Huang ◽  
Jianzhong Xu
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Empirical Model ◽  
The Other ◽  
Model Parameters ◽  
Model Parameter ◽  
Other Hand ◽  
Aero Engine ◽  
Semi Empirical

According to the Lefebvre's model and flame volume (FV) concept, an FV model about lean blow-out (LBO) was proposed by authors in early study. On the other hand, due to the model parameter (FV) contained in FV model is obtained based on the experimental data, FV model could only be used in LBO analysis instead of prediction. In view of this, a hybrid FV model is proposed that combines the FV model with numerical simulation in the present study. The model parameters contained in the FV model are all estimated from the simulated nonreacting flows. Comparing with the experimental data for 11 combustors, the maximum and average uncertainties of hybrid FV model are ±16% and ±10%.

Reduction of binary sulfate mixtures containing CuSO4 by H2

1976 ◽  
Vol 54 (23) ◽  
pp. 3651-3657 ◽  
Author(s):  
Fathi Habashi ◽  
Shaheer A. Mikhail
Keyword(s):  
Intermediate Product ◽  
The Other ◽  
Temperature Range ◽  
Other Hand ◽  
First Case ◽  
Limited Temperature ◽  
Limited Temperature Range ◽  
The Individual

The reduction of a binary sulfate mixture cannot be predicted from the behavior of the individual components. Thus, while CuSO4 is reduced to Cu at 400 °C and NiSO4 is reduced to Ni3S2, the sulfate mixture yields Cu, Ni3S2, and Cu2S. Also while FeSO4 is completely stable in H2 at 400 °C, (Cu,Fe) SO4 yields Cu and Cu5FeS4. The formation of Cu2S in the first case and Cu5FeS4 in the second was unexpected. On the other hand, (Cu,Mn)SO4 is stable in H2 up to 550 °C although pure CuSO4 is completely reduced at 400 °C. CoSO4 also interferes when reduced in presence of CuSO4, while Na2SO4, MgSO4, Al2(SO4)3, ZnSO4, CdSO4 do not interfere within limited temperature range. Of these only Na2SO4 forms a complex sulfate with CuSO4. No Cu2SO4 was identified when CuSO4 was reduced in presence of other sulfates although it is an intermediate product during the reduction of pure CuSO4.

FERROMAGNETIC TDAE-C60 VERSUS PARAMAGNETIC TDAE-C70: FARADEY BALANCE AND ESR STUDY

1992 ◽  
Vol 06 (23n24) ◽  
pp. 3953-3958 ◽  
Author(s):  
Kazuyoshi Tanaka ◽  
Anvar A. Zakhidov ◽  
Kazunari Yoshizawa ◽  
Kenji Okahara ◽  
Tokio Yamabe ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electron Spin Resonance ◽  
Electron Spin ◽  
Fullerene Molecule ◽  
The Other ◽  
Temperature Range ◽  
Type Transition ◽  
Other Hand ◽  
Spin Resonance ◽  
Ordered State

Magnetic properties of C 60 and C 70 complexes with tetrakis(dimethylamino)ethylene (TDAE) have been studied based on the measurements of the Faraday-balance magnetization and the electron spin resonance (ESR). It has been found that both TDAE- C 60 and TDAE- C 70 possess about one radical spin per fullerene molecule. TDAE- C 60 has been confirmed to show ferromagnetic-type transition at Tc=16.7–17.5 K . Appearance of a new broad and intense ESR signal below Tc of TDAE- C 60 suggests that the radical spins in the magnetically ordered state rather localize on each C 60 molecule and are ferromagnetically correlated. On the other hand, TDAE- C 70 does not show ferromagnetism in all the temperature range down to 4.5K.

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