Description of a new species of Afroedura (Loveridge) (Reptilia: Gekkonidae) from the south-western Cape

A new gekkonid species, Afroedura hawequensis, is described from the south-western Cape (South Africa). The three species groups recognized in the genus are discussed

Improving the Deviro panel : technical enhancements of a wood fibre-cement composite from paper mill de-inking sludge

Thesis (MScFor)--Stellenbosch University, 2004.ENGLISH ABSTRACT: This research focuses on the utilisation of de-inking sludge from a tissue mill to produce a wood-fibre inorganic composite called the Deviro panel. The study is based on the SA provisional patent 95/9594 by Ysbrandy and Gerischer' and the further research conducted by Crafford'. The patented Deviro panel contains up to 70% de-inking sludge. Cement and a cement extender serve to fortify the composite. The panel's fibre content of 25-30% is significantly greater than encountered in commercial fibre inorganic composites which contain 8-12% fibre by weight. The physico-mechanical characteristics of the Deviro panel compare favourably with resin bonded wood-fibre composites, but less favourably compared to conventional wood and wood-fibre inorganic composites. These properties are strongly dependent on panel density. For instance flexural strength being directly proportional while dimensional stability and hygroscopicity being inversely proportional to density. After confirming the results from the preceding work by Crafford, further improvements were investigated through chemical and curing enhancements. For instance, an autoclaving treatment during the curing period showed an increase in flexural strength. Addition of water glass could be associated with bulking of the panel, which resulted in increased flexural strength and a slight reduction of density. Panel density could be significantly reduced by the addition of Perlite, while inhibiting the concomitant reduction in strength. In addition a pilot production process was developed to produce 1m2 panels, which exhibited similar curing characteristics as the smaller panel units.AFRIKAANSE OPSOMMING: Hierdie navorsing handeloor die gebruik van ontinkingsslyk van 'n sneespapier meule om die Deviro paneel, 'n houtvesel anorganiese saamgestelde produk, te produseer. Die studie volg uit die SA voorlopige patent 95/9594 deur Ysbrandy en Gerischer en verdere narvorsing deur Crafford'. Die gepatenteerde Deviro paneel bevat tot 70% ontinkingsslyk. Sement en sement-byvoegmiddels dien om die saamgestelde produk te versterk. Die paneel bevat 25-30% vesel wat aansienlik meer is as ander kommersiële anorganiese saamgestelde produkte wat 'n vesel inhoud van 8-12% het. Die megamese eienskappe van die Deviro paneel is vergelykbaar met houtvesel saamgestelde produkte waar hars as kleefiniddel dien, maar vergelyk minder gunstig teenoor konvensionele hout en houtvesel anorganiese saamgestelde produkte. Die paneel se eienskappe is afhanklik van sy digtheid Buig sterkte is eweredig terwyl dimensionele stabiliteit en hygroskopisiteit omgekeerd eweredig aan die digtheid van die paneel is. Die voorafgaande werk van Crafford is eers gestaaf voordat veranderinge aan die chemiese samestelling en drogingsmetodes van die paneel nagevors is. Daar is byvoorbeeld bevind dat, deur die paneel te outoklaveer gedurende die set periode, dit lei tot 'n toename in buig sterkte. Die byvoeging van water glas kan swelling laat plaasvind wat 'n afname in buig sterkte en 'n afname in digtheid tot gevolg het. Digtheid kan ook aansienlik verlaag word deur die byvoeging van Perlite terwyl 'n dienooreenkomstige verlaging in buig sterkte tot 'n mate voorkom word. 'n Loods produksie proses is ook ontwikkel om 'n 1m2 paneel te vervaardig wat dieselfde eienskappe toon as die kleiner paneel

Late Effects of Therapy, Stigmatization and Social Reintegration following Childhood Cancer Survival in Kenya: A Case Report

Childhood cancer survival is increasing in low- and middle-income countries like Kenya, which comes with a new healthcare challenge: late effects and quality-of-life of survivors. A case was studied to depict a Kenyan Hodgkin lymphoma survivor, illustrating some of the childhood cancer survivors' difficulties in Kenya. Late effects of therapy, stigmatization and social reintegration were explored. The investigators reviewed medical records and used semi-structured interviews and stigma assessments using the Social Impact Scale. The survivor developed severe pulmonary hypertension during treatment with ABVD and salvage protocols. Three years after treatment, the patient experienced chemotherapy-induced late effects (chronic heart disease) that hindered personal care, social activities and job opportunities and required follow-up. Stigmatization by the community burdened his family life and marital prospects. This case report is one of the first that testifies of combined medical and psychosocial challenges that childhood cancer survivors may face in sub-Saharan Africa and underlines the need for a holistic approach

Susceptibility of Grapevine Sucker and Green Shoot Wounds to Trunk Disease Pathogens

Grapevine trunk disease fungi infect vines through openings, primarily pruning wounds. The main objective of this study was to understand the role of sucker wounds and wounds made by the removal of green shoots from the stems of potted grapevines as potential points of infection for grapevine trunk disease pathogens. Six wine and four table grape vineyards of different ages were sampled in differentproduction areas in the Western Cape grape region of South Africa. Isolations were made from 161 sucker wounds, and fungal pathogens were identified using morphology and DNA sequence analysis of the internal transcribed spacers (ITS1 and ITS2) and the 5.8S ribosomal RNA gene, the translation elongation factor 1alpha or the partial β-tubulin gene. The results show that 62% of the sucker wounds were infected by trunk disease pathogens, including Diaporthe ampelina, Diplodia seriata, Phaeomoniella chlamydospora, Phaeoacremonium minimum, Eutypella microtheca, Cryptovalsa ampelina and Neofusicoccum australe.  Diaporthe ampelina was the most common, followed by D. seriata and P. chlamydospora, in both the wine and table grape sucker wounds. Under glasshouse conditions, wounds made by the removal of young green shoots on one-year-old potted grapevine plants were inoculated with spore suspensions of D. ampelina, E. lata, N. parvum, P. minimum and P. chlamydospora. After four months, all the inoculated pathogens could be re-isolated. This study shows that grapevine sucker and green shoot wounds are susceptible to different grapevine trunk disease pathogens and may therefore play a role in the epidemiology of trunk diseases

Evolution of the chemical composition of Sn thin films heated during x-ray photoelectron spectroscopy

High-vacuum XPS have been used to analyse the surface modification of a 3 nm-thick Sn thin film on Si (100) before and after annealing up to 450 °C. Increasing the XPS stage temperature led to a reduction in the amount of surface Sn and increasing amounts of O and Si. High-resolution XPS scans revealed the presence of mostly pure Sn and SnO2 for the as-deposited Sn thin film. Increasing the XPS stage temperature to > 232 °C led to the conversion of SnO2 to SnO and an enhancing pure Sn signal. The Si2p and SiO2 peaks become prominent at temperatures > 350 °C, which in combination with scanning electron microscope images, signals the dewetting of the Sn film and subsequent exposure of the underlying Si (100) substrate. XPS depth profiles revealed the presence of a pure Sn metallic core encapsulated by a Sn-oxide shell. Electron microscope images shows a densely packed particulate surface features for the as-deposited Sn thin film. However, these particulate regions increase in size and are more isolated at XPS stage temperatures > 350 °C.National Metrology Institute of South Africa and the National Research Foundation (GUN: 93212, 92520, 103621)

A High-Efficiency 4x45W Car Audio Power Amplifier using Load Current Sharing

A 4x45W (EIAJ) monolithic car audio power amplifier is presented that achieves a power dissipation decrease of nearly 2x over standard class AB operation by sharing load currents between loudspeakers. Output signals are conditioned using a common-mode control loop to allow switch placement between loads with minimal THD increase. A prototype is realized in a SOI bipolar-CMOS-DMOS process with 0.5μm feature size. Die area is 7.5x4.6mm2. THD+N @(1kHz,10W) is 0.05%

Waardevol - Indicatoren voor Valorisatie

Het rapport Waardevol – Indicatoren voor valorisatie biedt kennisinstellingen, wetenschapsfinanciers en kennisgebruikers een gemeenschappelijk kader voor valorisatie. De methode werkt met valorisatiekaarten waarmee betrokken organisaties systematisch kunnen monitoren hoe groot de valorisatie-inspanningen zijn, wat de opbrengsten zijn en welke mogelijkheden voor verbetering er zijn. Het gebruik van valorisatiekaarten zal helpen om het inzicht te vergroten in wat publieke kennisinstellingen, wetenschapsfinanciers en bedrijfsleven nu al doen aan valorisatie.