33 research outputs found
Screening for antifungal activity of garlic (Allium sativum) powder against mycelia growth of three post-harvest pathogens
No full textScreening for antifungal activity of garlic powder against mycelia growth of three post-harvest pathogens (Aspergillus, Rhizopus and Mucor species) was investigated in this study. Five grams of malt extract agar (MEA) were poured into a conical flask, 100 ml of water and different weight of garlic powder (1, 3, 5 and 7 g) were separately added, stirred and later sterilized while MEA medium with no garlic added (0 g) served as control. The mycelia of each post-harvest pathogen was cut with 6mm cork borer and placed on the solidified medium in the Petri dish and incubated at 28±2oC for 72 hours. Phytochemical screening of the garlic powder was also investigated. Results from this study showed that the different weights of the garlic powder apart from the control (0 g garlic) significantly inhibited the mycelia growth of the three post-harvest pathogens tested in the study and the order of antifungal activity of the garlic powder against mycelia growth of Aspergillus, Rhizopus and Mucor species was 7 g > 5 g > 3 g > 1 g > 0 g, 5 g > 7 g >1 g > 3 g > 0 g and 7 g > 5 g > 3 g > 1 g > 0 g respectively. The antifungal activity of the garlic powder may be related to the presence of active antimicrobial agents including alkaloids, saponins, tannins, flavonoids and cardiac glycosides that were detected in the powder
Corrigendum to: The burden of COPD in Africa: a literature review and prospective survey of the availability of spirometry for COPD diagnosis in Africa
No full textIn [1], the second author's name was incorrect in the original published article. The author name should read as ‘Maxwell Oluwole Akanbi’ not ‘Akanbi Maxwell Oluwole’. The authors apologise for the error
Equal channel angular pressing technique for the formation of ultra-fine grained structures
No full textCITATION: Sanusi, K. O., Makinde, O. D. & Oliver, G. J. 2012. Equal channel angular pressing technique for the formation of ultra-fine grained structures. South African Journal of Science, 108(9/10), Art. #212, doi:10.4102/sajs.v108i9/10.212.The original publication is available at http://sajs.co.zaENGLISH ABSTRACT: Equal channel angular pressing is one of the techniques in metal forming processes in which an ultra-large plastic strain is imposed on a bulk material in order to make ultra-fine grained and nanocrystalline metals and alloys. The technique is a viable forming procedure to extrude materials by use of specially designed channel dies without substantially changing the geometry by imposing severe plastic deformation. This technique has the potential for high strain rate superplasticity by effective grain refinement to the level of the submicron-scale or nanoscale. Wereview recent work on new trends in equal channel angular pressing techniques and the manufacturing of die-sets used for the processing of metals and alloys. We also experimented on a copper alloy using the equal channel angular pressing technique to examine the microstructural, mechanical and hardness properties of the ultra-fine grained and nanocrystalline materials produced. After deformation, all samples were subjected to a hardness test and the results showed improved mechanical behaviour of the ultra-fine grained copper alloy that was developed. This research provides an opportunity to examine the significance of the equal channel angular pressing process for metals and alloys. That is, these ultra-fine grained materials can be used in the manufacturing of semi-finished products used in the power, aerospace, medical and automotive industries.AFRIKAANSE OPSOMMING: Geen opsomming beskikbaarhttp://sajs.co.za/equal-channel-angular-pressing-technique-formation-ultra-fine-grained-structures/sanusi-kazeem-makinde-oluwole-oliver-graemePublisher's versio
Studies of the properties of heat treated rolled medium carbon steel
No full textInvestigations were carried out to study critically the effects of heat treatment on the properties of rolled medium carbon steel. Representative samples of as-rolled medium carbon steel were subjected to heat treatment processes which are; Quenching, Lamellae Formation and Tempering in the following order (Q + Q + L + T), (Q + L + T) and (L + T). The steel was heated to the austenizing temperature of 830 ºC and water quenched. The quenched steel was subjected to lamellae formation by reheating it to the ferrite-austenite dual-phase region at a temperature of 745 ºC below the effective A C3 point and then rapidly quenched in water. The lamellae formed was tempered at 480 ºC to provide an alloy containing strong, tough and lath martensite in a soft and ductile ferrite matrix. Mechanical tests were carried out on the samples and the results shows that the steel developed has excellent combination of tensile strength, hardness and impact strength which is very good for structural applications. The corrosion behaviour of the samples; heat treated rolled medium carbon steel and as-rolled medium carbon steel in sodium chloride medium were also investigated from where it was also confirmed that improved corrosion resistance is achievable by the treatment
Tribute to the legend Mr. veterinary public health, Professor James Steele (1913 -2013): a late pioneer of one health in Nigeria
No full textBetween 2013 and 2014, the One Health World witnessed the demise of three pioneers of One Health in Nigeria- Professor Gabriel Oluwole Esuruoso, the Father of Veterinary Public Health in Nigeria, who died on 26lh January 2013 aged 80; Prof James Steele, often referred to as the “father of veterinary public health”, died Nov. 10 2013, aged 100 years old; and Prof David Goldsmith Montefiore who passed away on June 10 2014. aged 85. Nigeria was opportuned to have the One Health input of Prof James Steele known as “Mr. Veterinary Public Health’and acclaimed Father of Veterinary Public Health'. "Father of One Medicine" and founder and advocate of One World. One Health. One Medicine, who was invited in 1978 as Visiting Professor and External Examiner to the Department of Veterinary Public Health and Preventive Medicine by the Founding Head of Department. Prof G.O. Esuruoso, one of the earliest pioneers of One Health in Nigeria. The author was also destined during his Sabbatical Leave to have an interactive interview session with Prof James Steele after attending the 20th Annual James Steele lecture/ 99th birthday Dinner of Professor James Steele 4th and 6th April 2012 at the Texas School of Public Health, Houston. Texas. USA. The interview session was facilitated by a long time American veterinary epidemiology colleague and professional friend. Dr. Peter Cowen, a University of Ibadan 1978 DVM graduate. This article is a tribute to the memory of the late Prof James Steele for his contribution to the history of One Health in Nigeria, and shares his (and others’) perspectives on challenges and factors to hasten One Health in Nigeria
A Review of Isaac Oluwole Delano’s Pioneering Works on Yoruba Grammar, Orthography, Lexicography and Cultural Education.
No full textTis is a reproduction and an improved version of our opening chapter on Selected Works of Chief Isaac O. Delano on Yoruba Language. In it, we reintroduce the seminal works of the legendary writer and language educator, I. O. Delano. Many of these works have become obscure to the reading public due to an apparent lack of intentional publication. Delano, known for his prolific writings, wrote a few books relating to Yoruba language and grammar. Tis segment looks at four major non-fiction works of Chief Isaac O. Delano. For the most part, the segment deals with his efforts on Yoruba language, but to some extent, too, it looks at some additional non-language related writings often embedded in his works on language. For example, in Appendix I of his 1965 book, A Modern Yoruba Grammar, the author provides an array of proverbs and sayings in the language with their English equivalents. In Appendix II, Delano infused two old texts into the book, which comprise of a sermon and an essay on schooling. Clearly, Delano seems to have a penchant for dissemination of relevant cultural education in all his works. Indeed, one could say Yoruba Cultural education has always been apparently one of Delano’s passions as well as hidden agenda in writing his books, and he does so relentlessly. In what follows, we 216 Toyin Falola and Michael Oladejo Afolayan examine the four works in no particular order, although the Modern Grammar is given a relatively more detailed review and summarization. The four books are: A Modern Yoruba Grammar; Àgbékà Ọr̀ ọ̀ Yorùbá: Appropriate Words and Expressions in Yoruba; Conversation in Yoruba and English; and Atúmọ̀Èdè Yorùbá
A Review of Isaac Oluwole Delano’s Pioneering Works on Yoruba Grammar, Orthography, Lexicography and Cultural Education.
No full textTis is a reproduction and an improved version of our opening chapter on Selected Works of Chief Isaac O. Delano on Yoruba Language. In it, we reintroduce the seminal works of the legendary writer and language educator, I. O. Delano. Many of these works have become obscure to the reading public due to an apparent lack of intentional publication. Delano, known for his prolific writings, wrote a few books relating to Yoruba language and grammar. Tis segment looks at four major non-fiction works of Chief Isaac O. Delano. For the most part, the segment deals with his efforts on Yoruba language, but to some extent, too, it looks at some additional non-language related writings often embedded in his works on language. For example, in Appendix I of his 1965 book, A Modern Yoruba Grammar, the author provides an array of proverbs and sayings in the language with their English equivalents. In Appendix II, Delano infused two old texts into the book, which comprise of a sermon and an essay on schooling. Clearly, Delano seems to have a penchant for dissemination of relevant cultural education in all his works. Indeed, one could say Yoruba Cultural education has always been apparently one of Delano’s passions as well as hidden agenda in writing his books, and he does so relentlessly. In what follows, we 216 Toyin Falola and Michael Oladejo Afolayan examine the four works in no particular order, although the Modern Grammar is given a relatively more detailed review and summarization. The four books are: A Modern Yoruba Grammar; Àgbékà Ọr̀ ọ̀ Yorùbá: Appropriate Words and Expressions in Yoruba; Conversation in Yoruba and English; and Atúmọ̀Èdè Yorùbá
Influence of processed waste bagasse fiber-stone dust-6063 aluminum alloy particle on the characteristics of hybrid reinforced recycled HDPE composites
No full textA novel hybrid composites material was developed through the compression moulding technique by adding bagasse fiber, stone-dust and 6063 aluminum alloy (Al-Mg-Si) particles to recycled high density polyethylene (rHDPE) matrix. The bagasse fibers were treated with 0.5M Sodium Hydroxide solution at a temperature of 50 0C for 2hours while the stone-dust and 6063 aluminum alloy (Al-Mg-Si) particles were sieved to particle sizes of ˂75 µm and ˂250 µm, respectively before blending with the matrix. The work investigates comparatively, the influence of bagasse fiber-stone dust (hybrid-of-2) and bagasse fiber-stone dust-Al-Mg-Si particles (hybrid-of-3) on composite formation systems for reinforced rHDPE composites. The properties of recycled HDPE and rHDPE composites were thoroughly investigated through selected mechanical properties, wear resistance and thermal conductivity tests. The results showed that the addition of bagasse fiber-stone dust-Al-Mg-Si alloy particles improve the mechanical, wear and thermal properties of the composites. The ultimate tensile strength was enhanced by 39% having a UTS value of 32 MPa, tensile modulus by 13% with a value of 98 MPa and wear resistance by 53% with a value of 0.8 g. SEM images showed that these reinforcements blended more properly when lower contents were added. This was responsible for the enhancement observed in the mechanical properties of the hybrid-of-3 reinforced composite. Thus, composites from combination of waste materials can be projected for the development of new materials thereby reducing the creation of new ones
Processing and structural characterization of Si-based carbothermal derivatives of rice husk
No full textThe processing and structural characterization of Si-based carbothermal
derivatives of rice husk (RH) was investigated. RH, an agro-waste, was used as
starting material in a single-stage processing route to produce Si-based refractory
compounds via carbothermal treatment. The processing was carried out at different
temperatures windows (900–1,900°C) at 10°C/min heating range in a controlled
atmosphere. The functional groups of the reaction products were analyzed using
Fourier transform infrared spectroscopy. The crystalline and amorphous phases
were identified by X-ray diffractometer (XRD), while the morphological features
were examined by scanning electron microscopy. It was observed that the major
functional groups present after carbothermal treatment of RH are OH− (hydroxyl),
Si–O–Si (siloxane), and Si–C groups. However, polytypes of silicon carbide (SiC) such
as 3C-SiC (C = cubic), hexagonal symmetry 6H-SiC, and mixes of 3C-SiC, 2H-SiC, and
4H-SiC were various polytypes of SiC observed for different processing temperatures
adopted. The SiC made up between 63 and 74 wt.% of the crystalline phases was
identified by XRD from the process. Hence, the carbothermal treatment explore
