Dimensional Aggregate Research Articles

Simultaneous influences of hematocrit in the erythrocyte medium on erythrocyte aggregation and sedimentation: a kinetic study by a laser scattering technique

The erythrocyte aggregation is an important physiological phenomenon in the circulation of blood. It is a basic characteristic of normal blood that plays a major role in the cardiovascular system, especially in the microcirculation. This study explained the kinetics of single cells rouleaux formation one- dimensional aggregate and three- dimensional aggregate, during simultaneous, and the effect of hematocrit on the process of aggregation and sedimentation. The present study was done on forty one healthy subjects. Laser light is passed through a well mixed sample of blood and the forward scattered light intensities recorded continuously. The samples were prepared with different hematocrit, (10%, 15%, 20%, and 25%). Increasing the hematocrit, (10%, 15%, 20%, and 25%) had significantly decreased the rate of rouleaux formation (P< 0.005) but increase in the rate of one and three dimensional aggregate formation. On the other hand the sedimentation rate is decreased significantly (P

Synthesis and Structural Features of a Lithium Borate Derived from 2,2-Dipropylglycolic Acid

Abstract In this work, the synthesis and solid-state structure of a lithium borate with 2,2-dipropylglycolato (GlyPr2) ligand has been described. The desired lithium borate as well as previously reported borates with methyllactato (ML) and mandelate (Man) ligands could be synthesized rapidly and cleanly by using LiBH4 as a reagent in THF. The solid-state structures of the THF- and glyme-solvates of LiB(GlyPr2)2 (3 and 4) were determined by XRD analysis. Both these structures, except DME-solvate 4a, have one dimensional aggregate (AGG) form (1D-chain) that contains a µ2-borate fragment. In contrast, the THF-solvates with other borates derived from MLH2 and (S)-ManH2 (1 and 2) are less soluble in THF and have tighter AGG (2D-layer) with the µ3-borate fragment in the solid state.

Effect of presence of benzene ring in surfactant hydrophobic chain on the transformation towards one dimensional aggregate

The formation of wormlike micelle and the following significant changes in rheological properties suffer misunderstanding from both theoretical and fundamental aspects. Recently, we have introduced a theory for interpreting such important phenomenon which is referred to as critical intermolecular forces (CIF). The theory has stated that the hydrophobic effect is the main factor for the formation of worm-like aggregates. Therefore, it seems interesting to check out the validity of this new physical insight through investigating the presence of benzene ring as less hydrophobic group in contrast to that of alkyl in surfactant tail. The mixture of anionic sodium dodecylbenzenesulphonate (SDBS) and cationic cetyltrimethylammonium bromide (CTAB) shows a high dynamic viscosity peak at the ratio of 80/20 of 3wt.% CTAB/SDBS indicating the formation of wormlike micelles. The thermodynamic properties have been evaluated for this mixture exhibiting good agreement with the rheological changes. Interestingly, the results show the presence of benzene ring (in SDBS) causing a negative effect towards the formation of one dimensional aggregate in contrast to previous results which support the proposed CIF theory. The presence of nonionic surfactant TritonX-100 in binary and ternary systems of SDBS and CTAB prohibits the formation of wormlike micelles.

Simultaneous influences of hematocrit in the erythrocyte medium on erythrocyte aggregation and sedimentation: a kinetic study by a laser scattering technique

The erythrocyte aggregation is an important physiological phenomenon in the circulation of blood. It is a basic characteristic of normal blood that plays a major role in the cardiovascular system, especially in the microcirculation. This study explained the kinetics of single cells rouleaux formation one- dimensional aggregate and three- dimensional aggregate, during simultaneous, and the effect of hematocrit on the process of aggregation and sedimentation. The present study was done on forty one healthy subjects. Laser light is passed through a well mixed sample of blood and the forward scattered light intensities recorded continuously. The samples were prepared with different hematocrit, (10%, 15%, 20%, and 25%). Increasing the hematocrit, (10%, 15%, 20%, and 25%) had significantly decreased the rate of rouleaux formation (P< 0.005) but increase in the rate of one and three dimensional aggregate formation. On the other hand the sedimentation rate is decreased significantly (P

A Numerical Investigation of the Factors Influencing the Aggregate Shape of Carbon Black from the Furnace Process

In this study, a Monte Carlo simulation using an aggregate mean free path model is carried out for the aggregate formation of carbon black in the furnace process at different temperatures. A comparison of the results of two dimensional shape analysis of calculated aggregates and transmission electron microscope images of carbon black obtained from the furnace process shows that the aggregate shapes became complicated with an increase in temperature. In the furnace process, three factors (mean thermal velocity, particle number density, and primary particle diameter) vary simultaneously with temperature. Therefore, investigating the effect of each factor on the aggregate shape requires additional simulations while changing the individual factors. The results of two dimensional aggregate shape analysis shows that an increase in mean thermal velocity and particle number density contributes to complicating the aggregate shape and a decrease in primary particle diameter contributes to its simplification. On the other hand, the mean thermal velocity and particle number density are influenced by both the temperature and primary particle diameter; a decrease in primary particle diameter obviously contributes greatly to an increase in these factors and indirectly contributes to complication of the aggregate shape. Therefore, primary particle diameter is the most important factor in controlling the aggregate shape of carbon black in the furnace process.

Fracture Analysis for a 2D Prototype of Recycled Aggregate Concrete Using Discrete Cracking Model

Fracture analysis has been made for a 2 dimensional prototype of recycled aggregate concrete using the discrete cracking model. The discrete element method has been developed based on quasi-brittle constitutive law to simulate the behavior of the 2 dimensional recycled aggregate concrete prototype under uniaxial compressive loading. The relationship between stress distribution and failure mechanism of the recycled aggregate concrete plate has been investigated and analyzed. The numerical model proposed in the paper is in the first time used to analyze the mechanical properties of recycled aggregate concrete. Efficiency and accuracy of the numerical model has been demonstrated. It is indicated that this model has potential to be extended for 3 dimensional structural analysis of recycled aggregate concrete.

Exciton Theory by Second Quantization

Agranovich's solution of the molecular exciton problem, in which the representation of second quantization is used, was outlined. The assumptions of the theory, in particular the manipulation of excitons as bosons, were stressed. This technique allows a closed solution without the use of a perturbation expansion and formally simplifies the consideration of interactions with photons or phonons. Previous calculations implying major disagreement between second quantized results and those obtained by first-order perturbation theory are incorrect. A detailed comparison of the two theories for a perfect one- dimensional aggregate shows in general good agreement. Thus the use of either formalism is valid, the choice dictated by convenience of one or the other in the particular problem studied.

The third neighbourhood of a point in a plane

An unexceptionally birational model is constructed, in the form of a non singular algebraic threefold variety W, of the three dimensional aggregate of plane curve elements P0P1P2P3 of the third rank with origin at a fixed point P0 of the plane. The geometric properties of W are then examined, and a base for surfaces and curves on W found. In particular the mapping on W of the singular (for instance cuspidal) curve elements is clarified.