Studies on metal hydroxy compounds. VII. Thermal analyses of copper derivatives

1969 ◽  
Vol 47 (12) ◽  
pp. 2185-2190 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Thermal Stability ◽  
Thermal Analyses ◽  
General Pattern ◽  
The Other ◽  
Other Hand ◽  
Hydroxy Compounds ◽  
Initial Mode

Copper basic halide compounds have been studied by thermogravimetric and differential thermal analyses. This study reveals the general pattern of thermal stability observed for cadmium and zinc basic halides.The initial mode of decomposition varied within the copper group. The iodides, bromides, and chlorides all decomposed via dehydroxylation and in this way resembled the Cd and Zn basic halides. The copper basic fluorides, on the other hand, decomposed by simultaneous dehydroxylation and dehydrofluorination which is in distinct contrast to the Cd and Zn basic fluorides.

Constitutional History

2016 ◽  
Author(s):  
Olof Petersson
Keyword(s):  
Welfare State ◽  
General Pattern ◽  
Public Life ◽  
Constitutional Reform ◽  
The Other ◽  
Constitutional History ◽  
History Writing ◽  
Parliamentary Government ◽  
Other Hand ◽  
Trade Offs

In one sense, Sweden follows the general pattern of constitution-making. The major shifts in the constitutional history have occurred in the aftermath of great crises. Constitutions have been important as descriptions and justifications of the prevailing forces of power. On the other hand, the constitutions of Sweden have been relatively insignificant as norms regulating political and public life. Constitutions have been important as history writing but relatively unimportant as normative principles shaping society, and, indeed, profound changes such as the introduction of parliamentary government have taken place without constitutional reform. The Swedish welfare state was built upon negotiations and practical trade-offs rather than constitutional arguments.

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.

Oil Ring Design Influence on Lube Oil Consumption of SI Engines

2004 ◽  
Author(s):  
Andre´ Ferrarese ◽  
Fernando F. Rovai
Keyword(s):  
Thermal Stability ◽  
The Other ◽  
Oil Consumption ◽  
Ring Type ◽  
Full Load ◽  
Sealing Capacity ◽  
Other Hand ◽  
Actual Use ◽  
Si Engines ◽  
Load Conditions

2-piece and 3-piece oil ring designs were tested in dynamometer and vehicles in order to evaluate the ring type influence on lube oil consumption of spark ignited (SI) engines. The dynamometer tests were executed according a typical durability cycle of SI engines. This cycle is predominantly in full load conditions. Under these conditions, 2-piece oil ring design showed lower lube oil consumption than 3-piece. Two different vehicle tests were also run: urban and mountain circuits. The purpose of the urban circuit test was to simulate the actual use of the engine. The mountain circuit was selected to verify the rings behavior under motoring conditions. In vehicle tests, 3-piece showed lower or equivalent oil consumption than 2 piece, which disagreed with the dynamometer tests. This difference can be explained by the better side sealing capacity of the 3-piece oil ring. On the other hand, 2-piece oil rings present better conformability, important for applications with larger bore distortion. So, the most appropriate application of oil ring type depends on the load and speed conditions, in which the engine would predominantly operate. Ring wear and thermal stability are compared using bench and vehicle tests.

ZnAl2O4/Chitosan Films and Evaluation of the Influence of ZnAl2O4 Filler on the Films Morphology, Structure and Thermal Properties

2014 ◽  
Vol 775-776 ◽  
pp. 692-695
Author(s):  
Pascally M.A. Guerra de Araújo ◽  
P.T.A. Santos ◽  
Ana Cristina Figueiredo de Melo Costa ◽  
Edcleide Maria Araújo
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Flat Surface ◽  
Chitosan Film ◽  
The Other ◽  
Other Hand ◽  
Mass Proportion ◽  
Chitosan Films ◽  
Dta Curves

The present work intends to prepare ZnAl2O4/chitosan films with a mass proportion of 3:1and evaluate the influence of the ZnAl2O4 filler on the chitosan films morphology, structure and thermogravimetric properties. The films were characterized by XRD, SEM, TG and FTIR. With the XRD, it has been verified that both the chitosan and the ZnAl2O4/chitosan films presented the chitosan peaks. However, the ZnAl2O4/chitosan film also presented the ZnAl2O4 peaks. Through the SEM, it has been observed that the chitosan film presented a flat surface. On the other hand, the ZnAl2O4/chitosan presented a protruding surface. The TGA/DTA curves of the ZnAl2O4/chitosan film showed an increase in the thermal stability at temperatures greater than 720oC, comparing with the chitosan film.

Studies on metal hydroxy compounds. III. Thermal analyses of cadmium derivatives Cd(OH)2, CdOHCl, and CdOHF

1967 ◽  
Vol 45 (12) ◽  
pp. 1375-1378 ◽  
Author(s):  
O. K. Srivastava ◽  
E. A. Secco
Keyword(s):  
Thermal Stability ◽  
Thermal Analyses ◽  
Cadmium Oxide ◽  
Initial Step ◽  
Hexagonal Structure ◽  
Hydroxy Compound ◽  
The Stability ◽  
Hydroxy Compounds ◽  
Expected Increase ◽  
Thermal Stability Of

Thermogravimetric and differential thermal analyses of Cd(OH)2, CdOHCl, and CdOHF are reported and discussed. The results show that the presence of a halogen substituent contributes to greater thermal stability of the hydroxy compound. The thermal stability increases in the order Cd(OH)2 < CdOHF ≤ CdOHCl, which is in contrast with the order of the zinc derivatives.The expected increase in the stability of the cadmium hydroxy compounds relative to the zinc hydroxy compounds was observed except for CdOHF. The exception of CdOHF is ascribed to its departure from the expected hexagonal structure and its existence in the orthorhombic form.The cadmium hydroxy compounds decompose via dehydration in the initial step, followed by hydrolysis and (or) volatilization of the cadmium halide to yield an ultimate residue of cadmium oxide.

scholarly journals Influence of Al addition on the thermal stability and mechanical properties of Fe76.5-xCu1Si13.5b9Alx amorphous alloys

2012 ◽  
Vol 48 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Y.Y. Sun ◽  
M. Song
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Amorphous Alloys ◽  
Melt Spinning ◽  
The Other ◽  
Al Content ◽  
Amorphous Ribbons ◽  
Other Hand ◽  
Al Addition

This paper fabricated Fe76.5-xCu1Si13.5B9Alx (x=0,1,2,3,5,7 at.%) amorphous ribbons using singleroller melt-spinning method. The effect of Al content on the thermal stability and mechanical properties was investigated. The results indicated that Al addition have little effect on the amorphous formation ability of the alloys. On the other hand, increasing the Al content can substantially increase Tx2, which corresponds to the crystallization of Fe borides. Nanoindentation tests indicated that hardness of the alloys increase slightly with increasing the Al content, and Young?s modulus has a complicated relationship with the Al content.

scholarly journals Studies on Metal Hydroxy Compounds. XIV. Thermal Analyses, Calorimetry, and Decomposition Kinetics of Heterocationic Hydroxy Chloride Compounds

1973 ◽  
Vol 51 (23) ◽  
pp. 3882-3888 ◽  
Author(s):  
Ah-Dong Leu ◽  
Palepu Ramamurthy ◽  
Etalo A. Secco
Keyword(s):  
Thermal Decomposition ◽  
Rate Equation ◽  
Thermal Analyses ◽  
General Pattern ◽  
Type Equation ◽  
First Order ◽  
Order Rate ◽  
Kinetics Of ◽  
Order Rate Equation ◽  
Initial Mode

Studies were carried out on two series of mixed metal hydroxy chloride compounds of the type xMe(OH)2•yMCl2 where Me = Cd, Cu and M = Mn, Co, Ni, Cu, Zn, Cd, Mg, or Ca.Thermal analyses for the Cd–M series reveal that the initial mode of decomposition involves a dehydroxylation step with a concomitant metathetical reaction between MCl2 and CdO. The compound CdCl2•2CdO is formed and decomposes at higher temperature leading to the eventual volatilization of CdCl2. The kinetics of thermal decomposition follow a simple first-order rate equation. The sole exception to this general pattern of behavior is the Cd–Zn compound.The initial mode of thermal decomposition of the Cu–M series compounds follows a parallel pattern described for the Cd–M series. The kinetic data for the Cu–M series are fitted into three groups: (i) phase boundary control embracing the contracting sphere and contracting plate model equations, (ii) A-E type equation with n = 2, and (iii) first-order rate equation.

Studies on metal hydroxy compounds. I. Thermal analyses of zinc derivatives ϵ-Zn(OH)2, Zn5(OH)8Cl2.H2O, β-ZnOHCl, and ZnOHF

1967 ◽  
Vol 45 (6) ◽  
pp. 579-583 ◽  
Author(s):  
O. K. Srivastava ◽  
E. A. Secco
Keyword(s):  
Thermal Stability ◽  
Zinc Oxide ◽  
Thermal Analyses ◽  
Initial Step ◽  
Hydroxyl Group ◽  
Hydroxy Compound ◽  
Hydroxy Compounds ◽  
Hydrolysis Of ◽  
Thermal Stability Of

Thermogravimetric (t.g.a.) and differential thermal analyses (d.t.a.) of ϵ-Zn(OH)2, Zn5(OH)8Cl2.H2O, β-ZnOHCl, and ZnOHF are reported and discussed. The results show that the replacement of a hydroxyl group by a halogen group contributes to greater thermal stability of the hydroxy compound. The thermal stability increases in the order ϵ-Zn(OH)2 < Zn5(OH)8Cl2 < β-ZnOHCl < ZnOHF.The hydroxy compounds decompose via dehydration in the initial step followed by hydrolysis of the zinc halide and (or) volatilization of the zinc halide yielding an ultimate residue of zinc oxide and trace quantities of the zinc halide.

scholarly journals Effects of marginal vegetation removal on Odonata communities

2013 ◽  
Vol 25 (1) ◽  
pp. 10-18 ◽  
Author(s):  
Fernando Geraldo de Carvalho ◽  
Nelson Silva Pinto ◽  
José Max Barbosa de Oliveira Júnior ◽  
Leandro Juen
Keyword(s):  
Species Richness ◽  
Habitat Degradation ◽  
General Pattern ◽  
The Other ◽  
Minimum Width ◽  
First Order ◽  
Vegetation Removal ◽  
Habitat Integrity ◽  
Other Hand ◽  
Continuous Forest

AIM: Here we assess the effects of habitat degradation on individuals of the two suborders of Odonata community of Borecaia river sub-basin. More specifically, we tested the hypothesis that Anisoptera richness would be positively affected by removal of vegetation; on the other hand, Zygoptera richness would be adversely affected by virtue of their ecophysiological requirements; METHODS: We selected 10 streams of similar orders, six preserved and four degraded. Streams characterized as preserved had values of Index of Habitat Integrity (HII) above 0.70 (0.77 ± 0.07, mean ± SD) and continuous forest on both sides with a minimum width of 70 meters. Each site was sampled three times on different days. The effect of vegetation removal on richness was assessed using richness estimated by first order Jackknife; RESULTS: Decreased physical integrity (measured with IIH) of streams had no significant effect on the estimated richness to Odonata in general. However, the estimated richness of Anisoptera showed an inverse relationship with the integrity (r² = 0.485, P = 0.025), i.e., there was a reduction in their species richness with increasing integrity; DISCUSSION: As a general pattern, Anisoptera presents higher richness in an altered site; on the other hand, Zygoptera presents higher richness in a preserved one. This pattern suggests that Odonata needs to be considered at the sub-order level to access the effects of habitat degradation on these insects. Because of its restrictions ecophysiological Odonata varied widely in their composition and species richness between the two types of environments, it reinforces the potential of the order of studies and environmental monitoring also shows that Zygoptera be more affected by changes in habitat. However, further studies including more samples and different streams are need to confirm this pattern, being an interesting line of research for future works.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

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