Response time correlations for platinum resistance thermometers in flowing fluids

The thermal response of two types of Platinum Resistance Thermometers (PRT's), which are being considered for use in the National Transonic Wind Tunnel Facility, were studied. Response time correlations for each PRT, in flowing water, oil and air, were established separately. A universal correlation, tau WOA = 2.0 + 1264, 9/h, for a Hy-Cal Sensor (with a reference resistance of 100 ohm) within an error of 20% was established while the universal correlation for the Rosemount Sensor (with a reference resistance of 1000 ohm), tau OA = 0.122 + 1105.6/h, was found with a maximum percentage error of 30%. The correlation for the Rosemount Sensor was based on air and oil data only which is certainly not sufficient to make a correlation applicable to every condition. Therefore, the correlation needs more data to be gathered in different fluids. Also, it is necessary to state that the calculation of the parameter, h, was based on the available heat transfer correlations, whose accuracies are already reported in literature uncertain within 20-30%. Therefore, the universal response constant correlations established here for the Hy-Cal and Rosemount sensors are consistent with the uncertainty in the input data and are recommended for future use in flowing liquids and gases

EXPERIMENTATION SCIENCE: A PROCESS APPROACH FOR THE COMPLETE DESIGN OF AN EXPERIMENT

Experimentation Science is introduced as a process through which the necessary steps of experimental design are all sufficiently addressed. Experimentation Science is defined as a nearly linear process of objective formulation, selection of experimentation unit and decision variable(s), deciding treatment, design and error structure, defining the randomization, statistical analyses and decision procedures, outlining quality control procedures for data collection, and finally analysis, presentation and interpretation of results. The protocol description form (PDF) is introduced as an instrument to guide the implementation and documentation of the Experimentation Science process

Issues and challenges facing school libraries in selected primary schools in Gauteng Province, South Africa

There is no national policy for school libraries which compels school governing bodies and principals to have a library in their schools. It is thus not surprising that in 2011, only 21% of state schools had libraries, only 7% had stocked libraries and 79% of schools had no library at all (Department of Basic Education (DBE) Republic of South Africa, 2011a:23). This article forms part of a broader qualitative study which investigated 10 primary schools in Gauteng Province, South Africa that had libraries, or were in the process of setting up a library, with the intention of providing a rich description of the issues and challenges facing these schools. The 10 schools used in this study were chosen on the basis of their location and fee structures. They represented the full continuum of fees within the state structure. In this article, we discuss three core categories of predicaments faced by primary school libraries. These were resourcing the library, operating the library and the role of the library. Our main contention is that school libraries are not playing an effective role in supporting and enabling quality education for all South African children. This needs to be addressed by government as a matter of urgency.Keywords: academic achievement; books; information and communication technologies; information literacy; literacy; national school library policy; quality education; reading; school librarians; school librarie

Abrasion Caused by Three Methods of Toothbrushing

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141730/1/jper0434.pd

Fitting Voronoi Diagrams to Planar Tesselations

Given a tesselation of the plane, defined by a planar straight-line graph $G$, we want to find a minimal set $S$ of points in the plane, such that the Voronoi diagram associated with $S$ "fits" \ $G$. This is the Generalized Inverse Voronoi Problem (GIVP), defined in \cite{Trin07} and rediscovered recently in \cite{Baner12}. Here we give an algorithm that solves this problem with a number of points that is linear in the size of $G$, assuming that the smallest angle in $G$ is constant.Comment: 14 pages, 8 figures, 1 table. Presented at IWOCA 2013 (Int. Workshop on Combinatorial Algorithms), Rouen, France, July 201