Search results for "equation"
showing 10 items of 4219 documents
The influence of innovation stimulus, facilitating factors and support mechanisms on innovation performance in Brazilian small textile firms
2020
The ability of the organisation to develop new products is crucial in rapidly changing business environments, and thus, customer demographics, consumers' expectations and buying behaviour play an important role. Hence, exploring the antecedents of innovation performance becomes more important. This study analyses the relationships among innovation stimulus, facilitating factors and support mechanisms for innovative performance in the textile industry of Santa Catarina, Brazil. The sample included 128 respondents, who were all employees of five small and medium-sized textile firms; data were analysed using structural equation modelling. We found that innovation stimulus, facilitating factors…
Kinetik und Radikalausbeute beim Zerfall tertiärer Hyponitrite
1971
Der thermische Zerfall von Dicumylhyponitrit (1a) ist eine Reaktion erster Ordnung mit einer Aktivierungsenthalpie von 27.3 keal/Mol und einer Aktivierungsentropie von 8.5 cal/Mol·Grad in Isooctan. Die Radikalausbeute fur 1a betragt 84%, fur Di-tert.-butylhyponitrit 92%. Die Zerfallskonstanten substituierter Dicumylhyponitrite gehorchen bei Verwendung der σ+-Werte der Hammett-Beziehung mit σ=+ +0.34. Kinetic and Radical Efficiency for the Decomposition of Tertiary Hyponitrites The thermal decomposition of dicumylhyponitrite (1a) is a first order reaction with an activation enthalpy of 27.3 kcal/mole and an activation entropy of 8.5 e. u. in isooctane. The efficiency of radical formation is …
Hydrolysis and chemical speciation of (C2H5)2Sn2+, (C2H5)3Sn+ and (C3H7)3Sn+ in aqueous media simulating the major composition of natural waters
2001
The hydrolysis of (C 2 H 5 ) 2 Sn 2+ , (C 2 H 5 ) 3 Sn + and (n-C 3 H 7 ) 3 Sn + has been studied, by potentiometric measurements ([H + ]-glass electrode), in NaNO 3 , NaCl, NaCl/Na 2 SO 4 mixtures and in a synthetic seawater (SSWE), as an ionic medium simulating the major composition of natural seawater, at different ionic strengths (0 ≤ I ≤ 5 mol dm -3 ) and salinities (15 ≤ S ≤ 45), and at t = 25 °C. Five hydrolytic species for (C 2 H 5 ) 2 Sn 2+ , three for (C 2 H 5 ) 3 Sn + and two for (C 3 H 7 ) 3 Sn + are found. Interactions with the anion components of SSWE, considered as single-salt seawater, are determined by means of a complex formation model. A predictive equation for the calcul…
Experimental and theoretical study using DFT method for the competitive adsorption of two cationic dyes from wastewaters
2016
Abstract The adsorption of cationic dyes, Basic Yellow (BY28) and Methylene Blue (MB) on a new activated carbon from medlar species were studied in both single and binary system. Some experimental parameters, namely, pH, amount of adsorbent and contact time are studied. Quantum chemical results indicate that the adsorption efficiency was directly related to the dye electrophilicity power. Some theorical parameters were calculated and proved that MB is more electrophilic than BY28, than greatest interaction with surface sites. Kinetic study showed that the adsorption follows the pseudo-second-order model and Freundlich was the best model to describe the phenomenon in the single and binary sy…
Modeling plutonium sorption to kaolinite: Accounting for redox equilibria and the stability of surface species
2015
Abstract Plutonium with its particularly complex redox chemistry may be thermodynamically stable in the states + III to + VI depending on the redox conditions in the environment. Mineral surfaces can also affect Pu redox speciation. Therefore, the interpretation of Pu sorption data becomes particularly challenging, even for simplified laboratory experiments. The present study focuses on Pu sorption to kaolinite. Am(III), Th(IV), Np(V) and U(VI) literature sorption data are used as analogues for the corresponding Pu redox states to calibrate a simple surface complexation model, and the Nernst formalism is applied. Two independent pH–pe diagrams, one for the kaolinite surface and another for …
Towards efficient inductive synthesis of expressions from input/output examples
1993
Our goal through several years has been the development of efficient search algorithm for inductive inference of expressions using only input/output examples. The idea is to avoid exhaustive search by means of taking full advantage of semantic equality of many considered expressions. This might be the way that people avoid too big search when finding proof strategies for theorems, etc. As a formal model for the development of the method we use arithmetic expressions over the domain of natural numbers. A new approach for using weights associated with the functional symbols for restricting search space is considered. This allows adding constraints like the frequency of particular symbols in t…
The linear diophantine problem of Frobenius for subsets of arithmetic sequences
1997
Let A k = {a 1,. . . , a k } $ \subset \Bbb N $ with gcd (a 1,. . . , a k ) = 1. We shall say that a natural number n has a representation by a 1,. . . , a k if $ n =\sum \limits_{i=1}^{k}a_ix_i,\; x_i\in \Bbb N_0 $ . Let g = g (A k ) be the largest integer with no such representation. We then study the set A k = {a,ha + d,ha + 2d,..., ha + (k - 1) d} h,d > 0, gcd (a,d) = 1). If l k denotes the greatest number of elements which can be omitted without altering g (A k ), we show that ¶¶ $ 1-{4 \over \sqrt k} \le {l_k\over k} \le 1 - {3\over k}, $ ¶¶ provided a > k, or a = k with $ d \ge 2 h \sqrt {k} $ . The lower bound can be improved to 1 - 4 / k if we choose a > (k - 4) k + 3. Moreover, we…
A new result on impulsive differential equations involving non-absolutely convergent integrals
2009
AbstractIn this paper we obtain, as an application of a Darbo-type theorem, global solutions for differential equations with impulse effects, under the assumption that the function on the right-hand side is integrable in the Henstock sense. We thus generalize several previously given results in literature, for ordinary or impulsive equations.
On the integrability of the extended nonlinear Schrödinger equation and the coupled extended nonlinear Schrödinger equations
2000
We consider the extended nonlinear Schr¨ (ENLS) equation which governs the propagation of nonlinear optical fields in a fibre with higher-order effects such as higher-order dispersion and self-steepening. We show that the ENLS equation does not pass the Painlev´ test. Similarly, we claim that the coupled ENLS equations and N -coupled ENLS equations which govern the simultaneous propagation of two and more nonlinear fields in optical fibres are also not integrable from the Painlev´ e analysis point of view.
Spatially chaotic configurations and functional equations with rescaling
1996
The functional equation is associated with the appearance of spatially chaotic structures in amorphous (glassy) materials. Continuous compactly supported solutions of the above equation are of special interest. We shall show that there are no such solutions for , whereas such a solution exists for almost all . The words `for almost all q' in the previous sentence cannot be omitted. There are exceptional values of q in the interval for which there are no integrable solutions. For example, , which is the reciprocal of the `golden ratio' is such an exceptional value. More generally, if is any Pisot - Vijayaraghavan number, or any Salem number, then is an exceptional value.