The Influence of the Degree of Heterogeneity on the Elastic Properties of Random Sphere Packings

The macroscopic mechanical properties of colloidal particle gels strongly depend on the local arrangement of the powder particles. Experiments have shown that more heterogeneous microstructures exhibit up to one order of magnitude higher elastic properties than their more homogeneous counterparts at equal volume fraction. In this paper, packings of spherical particles are used as model structures to computationally investigate the elastic properties of coagulated particle gels as a function of their degree of heterogeneity. The discrete element model comprises a linear elastic contact law, particle bonding and damping. The simulation parameters were calibrated using a homogeneous and a heterogeneous microstructure originating from earlier Brownian dynamics simulations. A systematic study of the elastic properties as a function of the degree of heterogeneity was performed using two sets of microstructures obtained from Brownian dynamics simulation and from the void expansion method. Both sets cover a broad and to a large extent overlapping range of degrees of heterogeneity. The simulations have shown that the elastic properties as a function of the degree of heterogeneity are independent of the structure generation algorithm and that the relation between the shear modulus and the degree of heterogeneity can be well described by a power law. This suggests the presence of a critical degree of heterogeneity and, therefore, a phase transition between a phase with finite and one with zero elastic properties.Comment: 8 pages, 6 figures; Granular Matter (published online: 11. February 2012

Optimization of an Alkylpolyglucoside-Based Dishwashing Detergent Formulation.

The aim of this work was to formulate and optimize the washing performance of an alkylpolyglucoside-based dishwashing detergent. The liquid detergent was formulated with five ingredients of commercial origin: anionic (linear sodium alkylbenzenesulfonate and sodium laurylethersulfate), nonionic (C12–C14 alkylpolyglucoside) and zwitterionic (a fatty acid amide derivative with a betaine structure) surfactants, and NaCl for viscosity control. In addition to the plate test, other properties were investigated including ‘‘cloud point’’, viscosity, and emulsion stability. Statistical analysis software was used to generate a central composite experimental design. Then, a second order design and analysis of experiments approach, known as the Response Surface Methodology, was set up to investigate the effects of the five components of the formulation on the studied properties in the region covering plausible component ranges. The method proved to be efficient for locating the domains of concentrations where the desired properties were met

Penta­carbonyl-2κ5 C-chlorido-1κCl-bis­[1(η5)-cyclo­penta­dien­yl](μ-α-oxido­benzyl­idene-1:2κ2 O:C)titanium(IV)tungsten(0)

The title compound, [TiW(C5H5)2(C7H5O)Cl(CO)5], consists of two metal centres, with a (tungstenpenta­carbon­yl)oxy­phenyl­carbene unit coordinated by a titanocene chloride. The oxycarbene group is nearly planar, with the phenyl ring twisted by an angle of 39.1 (2)° with respect to this plane. One of the cyclo­penta­dienyl rings undergoes an offset face-to-face π–π inter­action [3.544 (6) Å] with the symmetry-related cyclo­penta­dienyl ring of a neighbouring mol­ecule

The effect of ochratoxin a in feed on the blood content of lipids and proteins in chickens

lstražen je utjecaj ohratoksina A u hrani na koncentraciju ukupnih masti, ukupnih bjelančevina i albumina, te na koncentraciju alfa1, alfa2, beta i gama-globulina u krvnoj plazmi pilića. Pilići kontrolne skupine hranjeni su komercijalnim starterom, II skupine istim starterom u koji je primiješano 0,5 ppm ohratoksina A, a koncentracija ohratoksina A u hrani III skupine pilića iznosila je 5,0 ppm. Koncentracija ohratoksina A od 0,5 ppm djelovala je nakon 56 dana pokusa na povećanje, a koncentracija od 5,0 ppm ohratoksina A na smanjenje sadržaja ukupnih lipida, ukupnih proteina te albumina u krvnoj plazmi pokusnih pilića. Koncentracija ohratoksina A od 5,0 ppm djelovala je na smanjenje sadržaja alfa1, alfa2; beta i gama-globulina u krvnoj plazmi pilića kroz cijeli pokusni period.The effect of ochratoxin A in the feed on the concentration of total lipids, total proteins and albumin, and on the concentration of alpha1, alpha2, beta and gamma globulins in the blood plasma of chickens was investigated. The chickens of the control group were fed with a commercial feed, the chickens of the second group received the same feed mixed with 0.5 ppm ochratoxin A and those of the third the same feed with 5.0 ppm ochratoxin A. After 56 days the concentration of 0.5 ppm ochratoxin A provoked a higher content of total lipids and total proteins in blood plasma. The concentration of 5.0 ppm ochratoxin A in feed reduced the content of total lipids, total proteins and albumin. The concentration of 5.0 ppm ochratoxin A reduced the content of alpha1, alpha2, beta and gamma globulins in the blood plasma of chickens