Search results for "Strength"
showing 10 items of 2415 documents
Influence of M23C6 carbides on the heterogeneous strain development in annealed 420 stainless steel
2020
Understanding the local strain enhancement and lattice distortion resulting from different microstructure features in metal alloys is crucial in many engineering processes. The development of heterogeneous strain not only plays an important role in the work hardening of the material but also in other processes such as recrystallization and damage inheritance and fracture. Isolating the contribution of precipitates to the development of heterogeneous strain can be challenging due to the presence of grain boundaries or other microstructure features that might cause ambiguous interpretation. In this work a statistical analysis of local strains measured by electron back scatter diffraction and …
Effects of nine months resistance training on cycling economy in elderly men and women
2016
The aging process, along with the lifestyle, is associated with loses in functional capacity and independence due to factors such as decreases in muscle mass, strength, and aerobic capacity, among others. Resistance training (RT) has been shown to induce strength and muscle size gains in the elderly. Improvements in maximal endurance capacity have been shown in some studies, while others have found no change. The purpose of the present study was to examine the effects of RT on the cycling economy in the elderly. A group of 47 older men and women (65-75 years) participated in the study. Subjects were assigned into one of two groups: 1) a training group performing 3 months of RT focusing on l…
Associations of physical activity and physical fitness with cardiovascular risk factors in young men
2015
Artikkeliväitöskirja. Sisältää yhteenveto-osan ja neljä artikkelia. Article dissertation. Contains an introduction part and four articles.
Activating Character Strengths Through Poetic Encounters in a Foreign Language - A Case Study
2016
The paper brings together two important issues related to effective functioning of foreign/second language learners, that is character strengths (one of the pillars of positive psychology) and the use of literary texts for language learning. The goals of using literary texts in a foreign/second language learning contexts and the goals of positive psychology converge. Both literature and positive psychology aim at enriching and expanding individual and social functioning and so they contribute to satisfaction and flourishing. The case study reported in the paper aimed at finding the participants’ opinions about the role of literary texts in foreign language learning and checking whether work…
Surface acidity studies on active aluminas by means of the amine titration method and heterogeneous isotopic exchange using HTO
1982
Abstract The maximum sorption capacity of n-butylamine (A + n-but ), the exchange capacity of HTO (A HTO ) and the acid strength distribution (ASD) - titration of n-butylamine using arylmethanols as indicators - were measured for a series of commercial active aluminas. A + n-but was formally regarded as total acidity and was found to be larger than A HTO , the latter representing a measure of the Broensted acidity. On the other hand, the cumulative acidity derived from ASD gave values smaller or equal to A HTO . Changes in A HTO and A + n-but within a series of aluminas manufactured at different calcination temperatures gave the expected results which were also supported by infrared spectro…
Fractionated precipitation of acid macropolyanions by dialysis, a simple method for the estimation of DNA in complex biological samples.
1976
Abstract After efficient extraction by para-aminosalicylate, (hopping, grinding and eventual sonication, the macropolyanions are transformed into their cetyltrimethylammonium salts. These have differing solubilities, strongly depending on ionic strength. The cationic detergent-macropolyanionic salts are solubilized by high salt concentration. Salt is then dialysed out, rendering the polyanions highly insoluble in a sequential fashion. The insolubilized components are determined quantitatively by monitoring turbidity, which in case of DNA is strictly proportionate to its concentration. This relation is not affected by other components. This makes DNA determination possible even in crude aque…
Structural and Transport Properties of Bola C-16 Micelles in Water and in Aqueous Electrolyte Solutions
2003
Aqueous solutions containing a bolaform surfactant [R,ω-(4,7,10,13-pentaoxa-16-azacyclooctadecane)- hexadecane], with and without electrolytes have been investigated as a function of surfactant concentration and ionic strength. Small angle neutron scattering (SANS), NMR self-diffusion, and other physical-chemical methods were used. From the analysis of SANS data it was inferred that in water the surfactant forms slightly charged ellipsoidal micelles, because of the partial hydrolysis of amino groups. The aggregates grow with the increase of concentration, becoming more elongated. Due to the selective complexing ability of aza crown ether units, significant differences were observed upon add…
Hydrolysis of (CH3)Hg+ in Different Ionic Media: Salt Effects and Complex Formation
1998
The hydrolysis of monomethylmercury(II) was studied potentiometrically, in NaNO3, Na2SO4, and NaCl aqueous solution, in a wide range of ionic strengths (NaNO3, 0 ≤ I ≤ 3.25; Na2SO4, 0 ≤ I ≤ 1; NaCl, 0 ≤ I ≤ 3 mol dm-3) and at t = 25 °C. For the reaction (CH3)Hg+ = (CH3)Hg(OH)° + H+, we found log K1 = −4.528 (I = 0 mol dm-3). The species [(CH3)Hg]2(OH)+ was also found, with log β2 = −2.15. Monomethylmercury(II) forms quite strong complexes with Cl- (log K = 5.45, I = 0 mol dm-3) and SO42- (log K = 2.64, I = 0 mol dm-3). The dependence on ionic strength of formation constants was considered by using a Debye−Huckel type equation. Hydrolysis and complex formation constants (at different ionic s…
Reversible swelling of polyanion/polycation multilayer films in solutions of different ionic strength
1996
Immersion of consecutively adsorbed polyanion/polycation multilayer films in solutions of different ionic strength causes reversible thickness changes. Swelling of the films up to 18% was observed after soaking the films in aqueous solutions of NaCl at concentrations up to 1.0 mol/l. X-ray reflectivity clearly shows that the thickness changes are reversible within experimental error and that the films seem to get smoother after several cycles of immersion in salt solutions and in pure water. The extent of swelling depends on the internal film structure, namely on the number of polyanion/polycation interfaces in a film of a given thickness. Interestingly, the swelling levels off at salt conc…
Transfer of Some Alkyl Substituted Ferrocenes from Water to Cationic Surfactant Micelles Studied by Kinetic Method
1994
Abstract Binding of ferrocene and its 1,1′-dimethyl and n -butyl derivatives to dodecyl and tetradecyltrimethylammonium nitrate micellar aggregates has been studied at 20.0°C and ionic strength 0.02 tool dm -3 by examining the micellar retarding effects on the rates of iron(III) oxidation of these substrates. Solubilization of the ferrocenes in the cationic micellar phase increases as the substrate hydrophobic character increases and, to a lesser extent, as the surfactant hydrocarbon chain length becomes longer. The critical micelle concentrations of the surfactants used and the incremental free energy of transfer of methylene groups of both the substrate and the surfactant from the aqueous…