2,444 research outputs found
S. J. du Plessis Collection index
No full textThis index describes the S. J. du Plessis collection which contains books with family history, youth memories, family trees and register of names ; albums with photos and newspaper clippings. 2 bound vol. in pamphlet box, 2 albums in pamphlet box ; 31 cm
Killer notches: The effect of as-built surface roughness on fatigue failure in AlSi10Mg produced by laser powder bed fusion
No full textAdditive manufacturing allows the production of complex components for critical applications such as in the aerospace industry. Laser powder bed fusion is the most widely used form of additive manufacturing and good progress has been made in improved material quality in recent years. Despite the progress, fatigue properties are sometimes still problematic and this requires further investigation. The fatigue properties of additively manufactured metals depend on a variety of factors including surface roughness, microstructure, porosity and residual stress, amongst others. In this work the role of surface roughness in particular is evaluated using micro computed tomography (microCT) scans before and after fatigue tests. The crack locations are identified in scans after fatigue testing and correlated with surface features prior to fatigue tests by careful alignment of CT images. In this way notches on the surface which act as “killer notches” are measured and compared with other defects (both roughness notches and pores) in the vicinity. Direct evidence is thereby provided for specific features acting as killer defects, studied with varying surface topographies depending on build orientation. A statistical analysis using stress intensity factor and fatigue test results of the same samples directly validate the effect of the notches, in comparison to other similar notches across the sample. This is the first notch-based surface roughness evaluation method reported using X-ray tomography, showing promise as analytical methodology. In addition, the experimental campaign shows for the first time a direct correlation of fatigue strength with surface roughness using different typical as-built surfaces. This work lays the foundation for improved non-destructive testing, predictive modelling and overall improvement and management of the performance of additively manufactured parts based on surface features and surface characterization
Précigné – Manoir du Plessis-Roland
No full textLe site du Plessis -Roland se situe à l’extrême sud-ouest du département de la Sarthe, à environ 15 km au sud de Sablé-sur-Sarthe sur la commune de Précigné. Depuis le Moyen Âge jusqu’à la fin de l’Ancien Régime, cet endroit correspond vraisemblablement à un site aristocratique, l’existence d’une résidence seigneuriale étant mentionnée par les sources écrites au début du xiiie s. À l’heure actuelle, aucune trace de ce logis ou de ses dépendances ne subsiste. Fig. 1 – Vue générale du manoir C..
MicroCT data for Tanaid specimen
No full textMicroCT stack of slice images of Tanaid crab that lives in small shell. Data set slice resolution (isotropic voxel size 2.028815 micrometers). MicroCT scanned at Stellenbosch CT facility using Nanotom S system, VGSTUDIO MAX 3.2 used for processing the data (de-noising)
South Africa's constitutional environmental right (generously) interpreted : what is in it for poverty?
No full textSection 24 of the Constitution of the Republic of South Africa, 1996 provides that everyone has the right to an environment that is not detrimental to his or her health or well-being. The nature and ambit of the environmental right relate to ss 27(1) and (2), which provide for a right of access to health-care services and sufficient food and water. Yet the scope of s 24 transcends the modalities of what is necessary for people's 'biological survival', including physical health. Departing from the viewpoint that a strong link exists between the vulnerable poor and the different constitutional entitlements enshrined in s 24, this article explores how poverty influences the way in which the normative content of the constitutional environmental right should be interpreted and applied. Following an interpretative approach, the call is made for an expansive or generous interpretation of the environmental right that takes into account the broader purposes and interests which this right and the Constitution in general, seem to protect
A minor character in C.S. Lewis's That Hideous Strength
No full textC. S. LEWIS’s That Hideous Strength, first published in 1945 in London and in 1946 in New York, is a novel in which Lewis allows his plot to develop as his characters present themselves in speech and action.1 Most of the complex plot unrolls through dialogue, with no more narrative than is necessary for coherence, and little authorial commentary. In this streamlined novel, one character initially seems to receive more attention than he needs: Captain O’Hara, second-in-command of the Institutional Police of the literally diabolical National Institute for Co-ordinated Experiments (N.I.C.E.). O’Hara is a minor character: Mark, one of the two protagonists, works and talks with him in section 2 of chapter 6, and he is mentioned in passing only twice more (ch. 7 § 4 & ch. 11 §..
The effects of microporosity in struts of gyroid lattice structures produced by laser powder bed fusion
No full textAdditive manufacturing by laser powder bed fusion allows the production of complex parts including lattice structures in popular metal alloys such as Ti6Al4V. Lattice structures are a class of meta-materials which hold many advantages such as the possibility for the production of lightweight parts with tailored mechanical and other properties: these have many potential applications in aerospace and medical fields. The laser powder bed fusion process can result in microporosity inside the produced material, which can affect the mechanical performance of these types of materials. In this work, different typical microporosity distributions are induced in manufactured gyroid lattice structure samples and the mechanical performance is tested by both static compression and compression-compression fatigue. X-ray tomography was used to validate the microporosity distributions and samples were tested in stress-relieved state and hot isostatic pressed state. In particular, it is found that small amounts of keyhole mode microporosity of ~0.2% make no difference while lack of fusion is critical, especially when this results in inefficient HIP pore closure. The results highlight the effect of microporosity on the mechanical performance of these materials and the results add to the knowledge base and trustworthiness of these materials. © 2018 The Author
Congenital CMV infection
No full textCITATION: Vlok, S. & Du Plessis, V. 2015. Meconium pseudocyst associated with congenital CMV infection. South African Journal of Radiology, 19(2), Art. #893, doi:10.4102/sajr.v19i2.893.The original publication is available at http://www.sajr.org.zaMeconium pseudocyst is a rare complication of fetal bowel perforation in utero, following extravasation and localised containment of meconium within the intra-peritoneal cavity.Publisher's versio
Engendered Representations: Exploring Sexuality through Symbols and Myths
No full textThis article reflects the findings of a project that was conducted by the Institute for Women�s and Gender Studies at the University of Pretoria. In particular, the project sought to dialogue with religious and cultural leaders on the taboos, myths and misconceptions of human sexuality.The article provides an analysis of the symbols and myths of sexuality that were presented by these leaders.These symbols and myths were demystif ed to reveal their alignment to patriarchal gender divisions and inequality.This alignment proves problematic for women, as it views men as possessors of their bodies � insofar as women�s bodies are conceived as the vessels for men�s body fluids and the container of the foetus.</p
Lexicon philosophicum, sive Index latinorum verborum descriptionumque ad philosophos & dialecticos maximè pertinentium ... /
No full textPlexiacus is pseudonym of Charles Du Plessis d'Argentré. Sometimes ascribed to M. BochardVingerafdruk 171604 - a1=a2 *2 tis - b1 A sa : b2 S ,Lammens, Pierre Philippe ConstantEuropeana-GoogleBook
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