98 research outputs found
Self Consistent Molecular Field Theory for Packing in Classical Liquids
Building on a quasi-chemical formulation of solution theory, this paper
proposes a self consistent molecular field theory for packing problems in
classical liquids, and tests the theoretical predictions for the excess
chemical potential of the hard sphere fluid. Results are given for the self
consistent molecular fields obtained, and for the probabilities of occupancy of
a molecular observation volume. For this system, the excess chemical potential
predicted is as accurate as the most accurate prior theories, particularly the
scaled particle (Percus-Yevick compressibility) theory. It is argued that the
present approach is particularly simple, and should provide a basis for a
molecular-scale description of more complex solutions.Comment: 6 pages and 5 figure
Model of a fluid at small and large length scales and the hydrophobic effect
We present a statistical field theory to describe large length scale effects
induced by solutes in a cold and otherwise placid liquid. The theory divides
space into a cubic grid of cells. The side length of each cell is of the order
of the bulk correlation length of the bulk liquid. Large length scale states of
the cells are specified with an Ising variable. Finer length scale effects are
described with a Gaussian field, with mean and variance affected by both the
large length scale field and by the constraints imposed by solutes. In the
absence of solutes and corresponding constraints, integration over the Gaussian
field yields an effective lattice gas Hamiltonian for the large length scale
field. In the presence of solutes, the integration adds additional terms to
this Hamiltonian. We identify these terms analytically. They can provoke large
length scale effects, such as the formation of interfaces and depletion layers.
We apply our theory to compute the reversible work to form a bubble in liquid
water, as a function of the bubble radius. Comparison with molecular simulation
results for the same function indicates that the theory is reasonably accurate.
Importantly, simulating the large length scale field involves binary arithmetic
only. It thus provides a computationally convenient scheme to incorporate
explicit solvent dynamics and structure in simulation studies of large
molecular assemblies
Photon interferometry and size of the hot zone in relativistic heavy ion collisions
The parameters obtained from the theoretical analysis of the single photon
spectra observed by the WA98 collaboration at SPS energies have been used to
evaluate the two photon correlation functions. The single photon spectra and
the two photon correlations at RHIC energies have also been evaluated, taking
into account the effects of the possible spectral change of hadrons in a
thermal bath. We find that the ratio for SPS and
for RHIC energy.Comment: text changed, figures adde
Customer emotions in service failure and recovery encounters
Emotions play a significant role in the workplace, and considerable attention has been given to the study of employee emotions. Customers also play a central function in organizations, but much less is known about customer emotions. This chapter reviews the growing literature on customer emotions in employee–customer interfaces with a focus on service failure and recovery encounters, where emotions are heightened. It highlights emerging themes and key findings, addresses the measurement, modeling, and management of customer emotions, and identifies future research streams. Attention is given to emotional contagion, relationships between affective and cognitive processes, customer anger, customer rage, and individual differences
Ação do cepa e do ácido giberélico na frutificação da videira 'niagara rosada'
Studies were carried out to establish the effects of exogenous growth regulators on Vitis (labrusca x vinifera) 'Niagara Rosada' fruiting. The investigations were done in the Jundiaí Research Station, Agronomic Institute State of São Paulo, always using disease-free vineyards of good productivity. The morphological transformations of clusters were carried out under the following aspects: weight, length and width of cluster; number of berries; weight, length average and width average of berries; length average/width average ratio of berries; number of seeds; length and diameter of secondary rachis. That characteristics were determined at the time of maturity plus the total sugars, total acid, Maturity Index and reducing sugars in samples of all treatments. The experiment were conduced in order to determine the doses that resulted in the most beneficial effects, always using applications by immersion of the inflorescence. The experiment consisted of appplications of (2-chloroethyl) phosphonic acid (CEPA) at concentrations of 50, 100, 250, 500, 1,000 and 2,000 ppm, 14 days before flowering; treatments with gibberellic acid at concentrations of 100 and 200 ppm before full bloom, 10 days after full bloom, and both before plus after full bloom. Treatment with CEPA 100 ppm plus gibberellic acid 100 ppm before full bloom and check treatment were also used. The use of CEPA before flowering at the concentrations used, did not result in good results in 'Niagara Rosada' clusters; applications of gibberellic acid did not differ significantly from the nontreated vines under the conditions studied.Estudou-se o efeito da aplicação, por imersão, do CEPA (ácido 2-cloroetil fosfônico) e do ácido giberélico, 14 dias antes do florescimento, nas características morfológicas da panícula da videira Vitis (labrus-ca x vinifera) "Niagara Rosada". Alguns tratamentos com ácido giberélico foram concluídos com nova aplicação 10 dias após o florescimento. Neste experimento verificou-se que, aplicação do CEPA na concentração de 250 ppm resultou na formação de panículas com a maioria de características indesejáveis. o tratamento misto CEPA 100 ppm + ácido giberélico 100 ppm também promoveu o aparecimento de panículas subdesenvolvidas. Aplicação de ácido giberélico na concentração de 100 ppm em pré e pós-ílorescimento, resultou médias mais elevadas, com relação ao peso da panícula, comprimento da panícula, peso das bagas e comprimento da ráquis. Ácido giberélico na concentração de 100 ppm aplicado em pós-ílorescimento, promoveu uma tendência de aumento nas médias do tratamento quanto ao comprimento médio das bagas, largura média das bagas, largura do engaço e comprimento da ráquila. Devemos considerar porém, que os resultados obtidos não apresentaram diferenças significativas com relação ao controle, quanto às características das frutificações, nas condições de estudo
Gravel-filling of shrinkage cracks in gold refining residue and its impact on rehabilitation in southwest Australia. 2. Movement of surface incorporated Gypsum
Gold refining residue at the Boddington Gold Mine is alkaline (pH 9.5 - 10), saline (6.35 dS/m) and sodic (67 -72 % exchangeable sodium). Previous research has shown that amelioration of these adverse properties can be achieved by incorporating 30 - 60 t gypsum/ha into the residue (Ho et al. 1999). The vertical depth of amelioration, however, is often restricted to the layer into which gypsum is incorporated (surface 30 cm), leaving the underlying residue unamended. This may have a detrimental effect on the growth of deep-rooted plant species used in the revegetation of the residue storage area. The present study was conducted to determine the importance of shrinkage cracks in the residue on the movement of calcium (Ca2+), measured as exchangeable Ca2+ (XCa), down the profile and to evaluate the effectiveness of gravel-filling of these cracks on the depth of amelioration
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