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Search Results: 1 - 10 of 324938 matches for " S. Matope "
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MICRO-MATERIAL HANDLING, EMPLOYING E-BEAM COATINGS OF COPPER AND SILVER
S. Matope,A.F. Van der Merwe,Y.I. Rabinovich
South African Journal of Industrial Engineering , 2012,
Abstract: ENGLISH ABSTRACT: Van der Waals forces and other adhesive forces impose great challenges on micro-material handling. Mechanical grippers fail to release micro-parts reliably because of them. This paper explores how the problematic Van der Waals forces may be used for micro-material handling purposes using surface roughnesses generated by e-beam coatings of copper and silver on silicon. An atomic force microscope, model Asylum MFP 3 D-Bio with version 6.22A software, was used to measure the forces exerted by the surfaces. A silver coating of 1.41 nm rms surface roughness value is found to exert the highest Van der Waals force, followed by a copper coating of 2.72 nm rms; a copper coating of 217 nm rms exerts the least force. This implies that, in a reliable micro-material handling system, these coatings are suitable for the interactive surfaces of the placement position, micro-gripper, and the pick-up position respectively. AFRIKAANSE OPSOMMING: Van der Waalskragte en ander bindingskragte hou steeds groot uitdagings in vir mikromateriaalhantering. As gevolg van hierdie bindingskragte stel meganiese gryptoerusting nie die mikro-partikels vry nie. Hierdie artikel ondersoek hoe die Van der Waalskragte gebruik kan word vir die mikro-materiaalhanteringsproses deur die gebruik van oppervlakgrofheid gegenereer deur ’n e-straal-laagbedekking van koper en silwer op silikon. ’n Atoomkrag mikroskoop, model Asylum MFP 3 D-Bio met weergawe 6.22A programmatuur, is gebruik om die kragte deur die oppervlakke uitgeoefen te meet. Daar is gevind dat ’n silwer laagbedekking met ’n oppervlakgrofheid van 1.41nm wortel-gemiddelde-kwadraat (wgk) die hoogste Van der Waalskrag uitoefen, gevolg deur ’n koper laagbedekking met ’n oppervlakgrofheid van 2.72nm wgk; ’n koper laagbedekking met ’n grofheid van 217nm wgk het die kleinste krag uitgeoefen. Dit impliseer dat, vir ’n betroubare mikro-materiaalhanteringsisteem, hierdie laagbedekkings geskik is vir die interaktiewe oppervlakke van die plasingsposisie, die mikro-gryper en die optelposisie.
MICRO-MATERIAL HANDLING EMPLOYING E-BEAM GENERATED TOPOGRAPHIES OF COPPER AND ALUMINIUM
S. Matope,A.F. van der Merwe,R. Nemutudi,M. Nkosi
South African Journal of Industrial Engineering , 2012,
Abstract: ENGLISH ABSTRACT: This paper focuses on the employment of copper and aluminium in a micro-material handling system actuated by Van der Waals forces. Electron beam (e-beam) evaporator deposited both materials on a silicon substrate at a rate of 0.6-1.2 Angstroms/second, vacuum pressure between 2x10-6 and 3x10-6mbar, and at a current less than 10mA. A Veeco NanoMan V Atomic Force Microscope with Nanoscope version 7.3 software was used to analyse the root mean square (rms) surface roughnesses of the generated topographies. Rumpf-Rabinovich’s rms formula was used to determine the Van der Waals forces exerted by the surfaces. It was synthesised that an e-beam deposition of 7 minutes’ duration on both materials produced an optimum micro-material handling solution, with copper suitable for the pick-up position and aluminium for the placement position. AFRIKAANSE OPSOMMING: Die fokus van die artikel is op die gebruik van koper en aluminium in ‘n mikromateriaalhanteringstelsel, aangedryf deur Van der Waalskragte. ‘n Elektronstraal-verdamper plaas albei materiale op ‘n silikonbasis teen ‘n tempo van 0.6-1.2 Angstrom/sekonde, vakuumdruk tussen 2x10-6 en 3x10-6mbar, en teen ‘n stroom van minder as 10mA. ‘n Veeco NanoMan V Atomic Force mikroskoop, met Nanoscope 7.3 program-matuur is gebruik om die wortel-gemiddelde-kwadraat (wgk) oppervlak ruheid van die gegenereerde topografie te analiseer. Rumpf-Rabinovich se wgk-formule is gebruik om die Van der Waalskrage wat deur die oppervlaktes uitgeoefen word te bepaal. Dit is vasgestel dat ‘n elektronstraalafsetting van 7 minute op albei materiale die optimale materiaalhanteringoplossing bied, met koper geskik vir die optelposisie en aluminium vir die plasingsposisie.
Gender Equality From A Gender Budgeting Perspective
Nyevero Maruzani,Nogget Matope,Efiritha Chauraya
International Journal of Asian Social Science , 2012,
Abstract: Gender budgeting, which is also known as gender responsive budgeting , tracks how budgets respond to gender equality and women’s rights requirement. This entails investing in and making available mechanisms, guidelines and indicators that enable gender equality advocates to track progress, benefit incidence and show how supposedly gender neutral budgets impact on men and women. The aim of this discussion is to highlight the importance of gender budgeting in addressing gender disparities while taking note of the fact that gender is a key variable in development. The term gender budgeting will be defined in an effort to show how the practice can lead to gender equitable resource allocation and improve revenue generation for nations. This enables government’s commitment to gender equality and women’s empowerment move from paper to practical policies .In gender budgeting there is the creation of awareness regarding gender specific issues in the policies of all government agencies. It also brings to light the effort of women in running the economy and attaining economic efficiency by including equity in budget performance indicators .Considering that most nations signed and ratified international commitments on gender equality and equity, it is expected of them to put in place realistic budgetary measures towards the achievement of gender equality .Despite the fact that gender budgeting is a relatively new concept, it is undoubtedly an important ingredient in quickening the attainment of the Millennium Development Goals and the fulfilment of international commitments on gender equality. The discussion concludes by highlighting success stories of gender budgeting initiatives in various countries in an effort to show how gender budgeting can be used as a tool for engendering macroeconomic policies.
Detection of Salmonella spp., Candida albicans, Aspergillus spp., and Antimicrobial Residues in Raw and Processed Cow Milk from Selected Smallholder Farms of Zimbabwe
Tryness Anastazia Mhone,Gift Matope,Petronella Tapiwa Saidi
Veterinary Medicine International , 2012, DOI: 10.1155/2012/301902
Abstract: A cross-sectional study was conducted to detect the presence of Salmonella spp., Candida albicans, Aspergillus spp., and antimicrobial residues in raw milk ( ) and processed cow milk ( ) from smallholder dairy farms from three sites in Zimbabwe. Culture and isolation of Salmonella spp., C. albicans, and Aspergillus spp. were performed using selective media, while antimicrobial residues were detected by a dye reduction test. No Salmonella, but C. albicans (17.5%; 21/120), Aspergillus spp. (0.8%; 1/120), and antimicrobial residues (2.5%; 3/120) were detected from raw milk. C. albicans was isolated from all three sites, while Aspergillus spp. and antimicrobial residues were detected from sites 1 and 3, respectively. From processed milk, only C. albicans (5%) was isolated while Aspergillus spp. and antimicrobial residues were not detected. These results suggested low prevalence of Salmonella spp. and Aspergillus spp. and a relatively high prevalence of C. albicans in raw milk from the smallholder farms. The potential public health risks of C. albicans and the detected antimicrobial residues need to be considered. Thus, educating farmers on improving milking hygiene and storage of milk and establishing programmes for monitoring antimicrobial residues may help to improve the safety of milk from smallholder farms. 1. Introduction Microorganisms such as bacteria and fungi which may gain entry into milk can multiply and bring about spoilage making raw or processed milk unsuitable for human consumption due to rancidity, musty odours, or toxin production [1]. The presence of these microorganisms usually indicates inadequate collection (milking) procedures, poor storage conditions, or unhygienic production [2, 3]. Raw and processed milk can be further rendered unsafe for human consumption by the mere presence of foodborne pathogens such as Brucella spp., Mycobacterium bovis, Listeria monocytogenes, Campylobacter jejuni, and Salmonella spp. which may not be associated with apparent food spoilage [1]. Contamination of raw milk and products with Salmonella spp. is mostly due to infected persons and contamination of the environment, since natural infections of the udder are rare and seldom contribute to human food poisoning. Deficient hygiene in dairies, especially those from developing countries, has often been considered as one of the major reasons for contamination of milk with both spoilage and pathogenic bacteria [2, 4]. Although poultry products are incriminated as the most common sources of nontyphoidal salmonellosis in humans [5], raw milk and milk products are
Prevalence of mastitis in dairy cows from smallholder farms in Zimbabwe
Simbarashe Katsande,Gift Matope,Masimba Ndengu,Davies M. Pfukenyi
Onderstepoort Journal of Veterinary Research , 2013,
Abstract: A cross-sectional study was conducted to determine the prevalence of sub-clinical and clinical mastitis and the associated factors in cows from selected smallholder dairy farms in Zimbabwe. Physical examinations were conducted on all lactating cows for evidence of signs of clinical mastitis. Composite milk samples were collected from all lactating cows for bacterial culture and somatic cell counting. Cows were categorised as clinical if they exhibited clinical features of mastitis, or sub-clinical if no apparent signs were present but they had a positive bacterial isolation and a somatic cell count of at least 300 x 103 cells/mL. Farm-level factors were obtained through a structured questionnaire. The association of mastitis and animal- and herd-level factors were analysed using logistic regression. A total of 584 animals from 73 farms were tested. Overall, 21.1%(123/584) had mastitis, 16.3%(95/584) had sub-clinical mastitis and 4.8% (28/584) had clinical mastitis. Herd-level prevalence was 49.3%. Coagulase-negative staphylococci (27.6%), Escherichia coli (25.2%), Staphylococcus aureus(16.3%), Klebsiella spp. (15.5%) and Streptococcus spp. (1.6%) were the most common isolates. In individual cows, pure dairy herds (OR = 6.3) and dairy crosses (OR = 3.1) were more likely to have mastitis compared to Mashona cows. Farms that used pre-milking teat dipping were associated with reduced mastitis prevalence. Further research is needed on the prevalence of mastitis and a comparison of data for both smallholder and commercial dairy farms in all regions of Zimbabwe should be undertaken.
Seroprevalence of leptospirosis in dogs in urban Harare and selected rural communities in Zimbabwe
Solomon Dhliwayo,Gift Matope,Lisa Marabini,Keith Dutlow
Onderstepoort Journal of Veterinary Research , 2012,
Abstract: A cross-sectional study was conducted to investigate seroprevalence of canine leptospirosis in urban Harare and five selected rural communities in Zimbabwe and to assess public awareness of the disease. Sera from randomly selected dogs were tested for antibodies to the serovars Canicola, Grippotyphosa, Icterohaemorrhagiae and Pomona of Leptospira interrogans using an enzyme-linked immunosorbent assay. Clinical chemistry was performed on all seropositive and selected seronegative sera to screen for hepatic and renal insufficiency. A questionnaire- based survey was conducted in Harare to assess dog owners’ awareness of leptospirosis and other zoonoses. Overall, 15.6% of sera samples tested (39 out of 250; 95% confidence interval [CI]: 11.0% – 20.2%) were positive for leptospiral antibodies. A significantly higher (p < 0.05) seroprevalence was recorded in urban dogs than in rural dogs (25% vs. 11.2%). No significant difference in seroprevalence was observed amongst dogs from different rural communities or between sexes of dogs. There was a significant association between seropositivity and hepatic and/or renal insufficiency (p < 0.01), with dogs having hepatic and/or renal insufficiency being approximately twice as likely to be seropositive (relative risk = 1.96; 95% CI: 1.3–3.0). Of the dog owners, 78.8% (119/151) were aware of zoonoses. Except for rabies (92.4%), awareness of leptospirosis (5.0%) and other zoonoses amongst these owners was low. This study showed that leptospirosis was present and represented a risk to dogs from urban Harare and the selected rural communities in Zimbabwe. Availing training programmes for dog owners would be beneficial in improving disease control and reducing the public health risk of pet zoonoses.
Characterization of some Brucella species from Zimbabwe by biochemical profiling and AMOS-PCR
Gift Matope, Evison Bhebhe, John Muma, Eystein Skjerve, Berit Dj?nne
BMC Research Notes , 2009, DOI: 10.1186/1756-0500-2-261
Abstract: Fourteen isolates of Brucella from culture collection were typed using biochemical profiles, agglutination by monospecific antisera, susceptibility to Brucella-specific bacteriophages and by AMOS-PCR that amplifies species- specific IS711. The results of the biochemical profiles for B. abortus biovar 1 (11 isolates) and biovar 2 (2 isolates) were consistent with those of reference strains. A single isolate from a goat originating from a smallholder mixed animal farm was identified as B. melitensis biovar 1. The AMOS-PCR produced DNA products of sizes 498 bp and 731 bp for B. abortus (biovar 1 and 2) and B. melitensis biovar 1, respectively.We concluded that the biochemical profiles and AMOS-PCR characterization were consistent with their respective species and biovars. B. abortus biovar 1 is likely to be the predominant cause of brucellosis in both commercial and smallholder cattle farms in Zimbabwe.The Brucellae are small Gram-negative coccobacilli bacteria affecting both animals and humans [1,2]. There are nine recognized species; B. abortus, B. melitensis, B. suis, B. canis, B. ovis, B. neotomae, B. ceti, B. pinnipedialis and B. microti [3-5]. On the basis of phenotypic profiles, some Brucella spp. are further divided into biovars [3].Studies of the genome of Brucella spp. have demonstrated the existence of more than 70% homology [6] and based on DNA-DNA hybridisation, a single species, B. melitensis was once proposed, with the other species being biovars [7]. However, the traditional classification into nine different species is still used. This has been further supported by the recent discovery of B. ceti and B. pinnipedialis from marine mammals [5], or B. microti from a common vole Microtus arvalis [4]. The genomic similarity makes the differentiation of Brucella spp. difficult, and often a study of biological and physiological characteristics is required [3].In Zimbabwe, only B. abortus and B. melitensis have been reported to cause animal brucellosis. B. meli
Study of the Structural and Electrical Properties of Cr-Doped BiFeO3 Ceramic  [PDF]
S. S. Arafat, S. Ibrahim
Materials Sciences and Applications (MSA) , 2017, DOI: 10.4236/msa.2017.810051
Abstract: Multiferroic BiFe1-xCrxO3 (x = 0.2 and 0.4) ceramics were synthesized in a single phase. The effects of Cr3+ substitution on the crystal structure, dielectric permittivity and leakage current were investigated. Preliminary X-ray structural studies revealed that the samples had a rhombohedral perovskite crystal structure. The dielectric constant ε' significantly increased while the dielectric loss tanδ was substantially decreased with the increase in Cr3+ substitution. The temperature effect on the dielectric properties exhibited an anomaly corresponding to magneto-electric coupling in the samples and was shifted to lower temperatures with the increase in Cr3+ substitution. The leakage current density also reduced in magnitude with the increase in the Cr3+ substitution.
Degree Splitting of Root Square Mean Graphs  [PDF]
S. S. Sandhya, S. Somasundaram, S. Anusa
Applied Mathematics (AM) , 2015, DOI: 10.4236/am.2015.66086
Abstract: Let \"\" be an injective function. For a vertex labeling f, the induced edge labeling \"\" is defined by, \"\" or \"\"; then, the edge labels are distinct and are from \"\". Then f is called a root square mean labeling of G. In this paper, we prove root square mean labeling of some degree splitting graphs.
A Parameter Estimation Model of G-CSF: Mathematical Model of Cyclical Neutropenia  [PDF]
S. Balamuralitharan, S. Rajasekaran
American Journal of Computational Mathematics (AJCM) , 2012, DOI: 10.4236/ajcm.2012.21002
Abstract: We investigate the FFT (Fast Fourier Transform) model and G-CSF (granulocyte colony-stimulating factor) treatment of CN (Cyclical Neutropenia). We collect grey collies and normal dog’s data from CN and analyze the G-CSF treatment. The model develops the dynamics of circulating blood cells before and after the G-CSF treatment. This is quite natural and useful for the collection of laboratory data for investigation. The proposed interventions are practical. This reduces the quantity of G-CSF required for potential maintenance. This model gives us good result in treatment. The changes would be practical and reduce the risk side as well as the cost of treatment in G-CSF.
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