On the Viscosity of Human Blood Plasma and Serum in Health and Disease

(1) The history of the development of the Plasma Viscosity Test from the Erythrocyte Sedimentation Rate Test by Whittington and Miller, in tuberculosis, has been described. (2) The events leading up to my own interest in this test have also been related and how I have become the principal worker in the later developments of the test. (3) The physical property of ordinary liquids named "Viscosity" has been defined. (4) Fluids have been divided into "Newtonian" and "non-Newtonian"; the non-Newtonian liquids have only "apparent viscosities" as the corresponding physical property varies according to the conditions under which it is measured. (5) Plasma and serum are non-Newtonian liquids. (6) A technique for the accurate estimation of the viscosity of small volumes of plasmata has been given in detail. (A) Preclinical Part. (7) The potential errors of the technique have been discussed and have been shown to be less than 1 % theoretically and still less practically. (8) Venous stasis must be avoided during the venipuncture. (9) Significant errors can be introduced into the plasma viscosity estimation by centrifuging with un-capped tubes. Evidence is given for a marked degree of concentration of the plasma by such treatment; most measurements of the constituents of the plasma must be similarly affected. (10) A significant change can be caused in the plasma viscosity by a delay in the separation of the plasma from the erythrocytes, either before or after centrifuging. (11) The viscosity of a plasma is not affected by mechanical violence. (12) Neither is it affected by standing on a bench for five days with precautions taken only against loss by evaporation. (13) The viscosity of plasma decreases by approximately 2.35 % for each rise in temperature by one degree centigrade. (14) The viscosity of a plasma estimated at 2

The effect of particle elongation on the strength of granular materials

It has long been recognised that the macroscopic mechanical behaviour of a granular material depends on particle shape. However, a systematic investigation into particle shape is lacking. Particle shape is commonly split into the independent categories of form, angularity and roughness. The form of a particle can be quantified using the Longest (L), Intermediate (I) and Shortest (S) dimension of an equivalent scalene ellipsoid; two independent parameters of particle form are defined, termed platyness and elongation.We use DEM simulations with the Potential Particle Method to investigate the effect of particle form on the friction angle of a granular material at critical state. It is found that deviation of particle form from that of a sphere leads to higher angles of friction at critical state. It is argued that, to some extent, the higher critical state strength exhibited by non-spherical particles is due to form suppressing particle rotation and leading to increased interparticle sliding, a mechanism that in comparison requires more energy to be expended

An investigation into the effect of particle platyness on the strength of granular materials using the discrete element method

It has long been recognised that the macroscopic mechanical behaviour of a granular material depends, to differing extents, on micro-mechanical properties such as the particle size distribution, the particle shape, the inter-particle friction angle and the particle strength. However, a systematic investigation of some of these effects is still lacking. In this paper we focus on particle shape, which is one of the fundamental characteristics of a granular material. We build on previous work that used the axes of an equivalent scalene ellipsoid to characterise particle form, one of the three aspects that define particle shape. (The other two being angularity and roughness.) We use DEM simulations to investigate the effect of particle form, and in particular of particle platyness, on the friction angle of a granular material at critical state. It is found that a deviation of particle shape from that of a sphere leads to higher angles of friction; quantities such as fabric, average rates of particle rotation and interparticle sliding are used to provide insights into the underlying micromechanics

Fully-Coupled Simulation of Cosmic Reionization. I: Numerical Methods and Tests

We describe an extension of the Enzo code to enable fully-coupled radiation hydrodynamical simulation of inhomogeneous reionization in large $\sim (100 Mpc)^3$ cosmological volumes with thousands to millions of point sources. We solve all dynamical, radiative transfer, thermal, and ionization processes self-consistently on the same mesh, as opposed to a postprocessing approach which coarse-grains the radiative transfer. We do, however, employ a simple subgrid model for star formation which we calibrate to observations. Radiation transport is done in the grey flux-limited diffusion (FLD) approximation, which is solved by implicit time integration split off from the gas energy and ionization equations, which are solved separately. This results in a faster and more robust scheme for cosmological applications compared to the earlier method. The FLD equation is solved using the hypre optimally scalable geometric multigrid solver from LLNL. By treating the ionizing radiation as a grid field as opposed to rays, our method is scalable with respect to the number of ionizing sources, limited only by the parallel scaling properties of the radiation solver. We test the speed and accuracy of our approach on a number of standard verification and validation tests. We show by direct comparison with Enzo's adaptive ray tracing method Moray that the well-known inability of FLD to cast a shadow behind opaque clouds has a minor effect on the evolution of ionized volume and mass fractions in a reionization simulation validation test. We illustrate an application of our method to the problem of inhomogeneous reionization in a 80 Mpc comoving box resolved with $3200^3$ Eulerian grid cells and dark matter particles.Comment: 32 pages, 23 figures. ApJ Supp accepted. New title and substantial revisions re. v

The Role of the Elementary School Principal in Administration of Cuisenaire Materials

It was the purpose of this study (1) to review literature regarding new trends in the elementary arithmetic program; (2) to investigate the role of the elementary school principal in administration of Cuisenaire materials; and (3) to investigate the current elementary arithmetic programs in the Highline School District #401 and, where evidence was available, in other school districts using Cuisenaire materials. The program in the Highline School District was investigated to determine the curricular goals and content of schools using Cuisenaire materials and of schools not using such. Other school districts using Cuisenaire materials were investigated to obtain further results of the program as well as information concerning the administrator\u27s role. The writer found it necessary to interview principals in the Highline School District to obtain evidence

Invasive Amebiasis in Men Who Have Sex with Men, Australia

Entamoeba histolytica is a pathogenic ameba that has recently been recognized as an emerging pathogen in men who have sex with men (MSM) in Asia-Pacific countries where it is not endemic, i.e., Japan, Taiwan, and Republic of Korea. We report locally acquired invasive amebiasis in Sydney, Australia, exclusively in MSM

A COST-EFFECTIVE MODEL FOR TEACHING ELEMENTARY STATISTICS WITH IMPROVED STUDENT PERFORMANCE

Dissatisfaction with teaching a high enrollment introductory statistics course led to efforts to restructure the course to remedy the perceived problems, including lack of student participation, an excessive drain on departmental resources, failure to take into account wide differences in student learning styles, an inability of students to apply statistics after the course, and negative attitudes of students. A cost-effective redesign of the course was implemented that incorporates a learning environment that is student-oriented, involves active student participation and hands-on experience with data analysis, uses technology to reduce costs through labor-saving techniques including low-stakes computerized testing, and sharing of resources enabled by a web site for course management and delivery of course materials. Responsibility for learning basic concepts was transferred to students and motivated by readiness assessment quizzes. The redesign led to about $125,000 in cost savings to the department