Novel Applications of Aluminium Metal Matrix Composites

Advanced materials have offered the materials designer a wide range of options in the specification and selection of materials for various applications. Material properties are continually being improved to meet safety and operational standards in line with prevailing technological developments. Modern technological requirements, together with the consumers’ demands for systems and machines that are more energy efficient, stronger, light-weight, cost-effective, etc., dictate that the search for new and advanced materials will remain a subject of interest all the time. The difficulty in designing materials for such stringent specifications cannot be overstated, owing to the conflicting nature of these specifications. Aluminium metal matrix composites (AlMMCs) are a class of materials that have proven successful in meeting most of the rigorous specifications in applications where light-weight, high stiffness and moderate strength are the requisite properties. With a variety of reinforcement materials and flexibility in their primary processing, AlMMCs offer great potential for the development of composites with the desired properties for certain applications. In this review, the development, utilisation and future potential of AlMMCs in various industrial and commercial applications is discussed, together with the existing challenges hindering their full market penetration

Production of carbonized briquettes from charcoal fines using African Elemi (Canarium Schweinfurthii) resin as an organic binder

This research article was published by Taylor & Francis Group, 2021This study investigated the use of African Elemi (Canarium Schweinfurthii) resin as a binder for the production of carbonized briquettes from charcoal fines. The binder and charcoal fines were characterized through proximate analysis, ultimate analysis, higher heating value, and SEM. Four briquette samples (B25, B30, B35, and B40) with a ratio of charcoal fines: binder of 3:1, 7:3, 13:7, and 3:2, respectively, were produced at a compaction pressure of 5.92–7.96 MPa. The physical properties of the briquettes determined were bulk density, impact resistance index (IRI), compressive strength, splitting tensile strength, water resistance index (WRI), and morphology. The chemical properties of the briquettes determined were proximate analysis, ultimate analysis, higher heating value (HHV), and energy density. One-way ANOVA and Fisher’s LSD were used to analyze the chemical properties of briquettes. The briquettes had a bulk density of 0.770–1.036 g/cm3, IRI of 2.90–73.33, compressive strength of 2.25–10.94 N/mm2, splitting tensile strength of 0.09–0.42 N/mm2, WRI of 99.26–99.29, and an HHV of 29.7–31.3 MJ/kg. The briquette properties were found to be comparable to results from other studies.This research article was published by Taylor & Francis Grou

Water Boiling Test of carbonized briquettes produced from charcoal fines using African Elemi (Canarium schweinfurthii) resin as an organic binder

This research article was published by Springer Nature Switzerland AG., 2021The study evaluated carbonized briquettes produced from charcoal fines using African Elemi (Canarium schweinfurthii) resin as a binder. Briquette samples (B25, B30, B35, B40) with the ratio of charcoal fines:binder of 3:1, 7:3, 13:7, and 3:2, respectively, were produced. The phases of the Water Boiling Test (WBT) considered were Cold start high power (CSHP), Hot start high power (HSHP), and simmer phases. Ignition properties, combustion properties, gas temperature, water temperature, ambient temperature, emissions, and WBT performance metrics were investigated using the Laboratory Emission Monitoring System. The ignition properties evaluated included ignition time, flame, and incandescence. The combustion properties included smoke, flame, soot, and ash. The emissions measured were PM2.5, SO2, NOx, CxHy, CO, and CO2. The WBT performance metrics evaluated were time to boil, burning rate, thermal efficiency, specific fuel consumption (sfc), firepower, total emissions, emissions per MJ, specific emissions, and emissions rate. The ash from charcoal fines was analysed using x-ray diffraction. The results showed that ignition time was 6.47–7.01 min, time to boil was 14.7–41.9 min, burning rate was 1.1–8.2 g/min, thermal efficiency was 21.79–54.61%, sfc was 21.7–70.1 g/L, and firepower was 535.9–4123.2 W. The ash was found to contain CaCO3 (76.6 wt%) followed by CaO (13.1 wt%) and the remainder was the amorphous compounds (10.3 wt%). The briquettes can be used as an alternative source of fuel to wood fuel since they exhibit similar combustion properties

Agony resulting from cultural practices of canine bud extraction among children under five years in selected slums of Makindye : a cross sectional study

Background: Canine Bud Extraction (CBE) is a process of removing or gouging children's healthy canine tooth buds embedded underneath the gum using traditional unsterilized tools. The practice of CBE commonly known as false teeth removal continues to be an adopted cultural intervention of choice, in the prevention of morbidity and mortality from common childhood illnesses. However, it is a practice against the rights of the children with serious consequences. While CBE is associated with the perceived myth of curative gains, the agony emanating from the cultural practice exposes children to ill-health conditions such as dehydration, malnutrition, blood-borne diseases like HIV/AIDs, septicemia, fever and death. This research sought to understand the factors underpinning the practice of CBE among urban slum dwellers. Method: A cross-sectional study was conducted from five randomly selected slums in Makindye division; 298 household heads or guardians with children below 5 years, who had ever suffered from false teeth were interviewed. The variables measured included guardians' socio-demographic profiles, determinants of CBE, common childhood illnesses assumed to be treated with CBE and the reported side-effects associated with the practice. Results: Of the 298 respondents with children who had ever suffered from "false teeth" interviewed, 56.7% had two or more children below 5years and 31.9% were from the central region. The proportion of households practicing CBE was 90.3%; 69.8% of the caretakers mentioned that it was done by traditional healers and for 12.1% by trained health workers (dentists). Number of children (OR=2.8, 95% CI: 1.1-7.2) and the belief that CBE is bad (OR=0.1, 95% CI: <0.001, p<0.001) had a statistically significant association with CBE. Additionally, number of children (χ2=4.9, p=0.027) and 2 sets of beliefs (CBE treats diarrhea (χ2=12.8, p=0.0017) and CBE treats fever (χ2=15.1, p=0.0005) were independent predictors of CBE practice. A total of 55.7% respondents knew that there were side effects to CBE and 31% mentioned death as one of them. Conclusion: The high proportion of households practicing CBE from this study ought to awaken the perception that the practice is ancient. CBE in this community as the study suggests was strongly driven by myths. The strong belief that CBE is bad provides an opportunity for concerted effort by primary health care providers, policy makers and the community to demystify the myths associated with false teeth and the gains of CBE

Интересы социально-экономических субъектов как социальный фактор экономической интеграции на постсоветском пространстве

Материалы ХI Международной науч.-техн. конф. студентов, магистрантов и аспирантов [28-29 апреля 2011 г., г. Гомель]. - Гомель, 2011

Characterisation of Ugandan raw-minerals for firebricks -before and after sintering.

Development of products which can be produced from acountry's natural resources is very important as far as theindustrialization of a nation and saving foreign exchange isconcerned. Presently, industries in Uganda and the other statesin the Lake Victoria region import allrefractory-related-consumables, as the demand cannot be metlocally. Based on the abundance of ceramic raw materials forhigh temperature applications in the region and the demand forrefractories by industries it is pertinent to develop andmanufacture firebricks by exploiting the locally available rawmaterials. This thesis thus, concerns the characterisation of ceramicraw mineral powders from in the Lake Victoria region, moreparticularly, Uganda, with the aim of developing firebrickrefractories from the minerals. Two main deposits of kaolin anda fireclay deposit, located in the Lake Victoria Region,Uganda, were investigated to assess their potential in themanufacture of refractory bricks. Raw- and processed samplepowders were investigated by means of x-ray diffraction (XRD),thermal analysis (DTA-TG) and Scanning Electron Microscopy(SEM). In addition, the chemical composition, particle sizedistribution, density, and surface area of the powders weredetermined. A general production process scheme for manufacture offirebricks starting with raw powder minerals (Mutaka kaolin andMukono ball clay) was used to make six groups of samplefirebrick. Experimental results from the characterization offormulated sample bricks indeed reveal the viability ofmanufacturing firebricks from the raw minerals.Characterization of the sample bricks has been done fordetermination of physical and mechanical properties; density,shrinkage, porosity, water absorption, and phaseidentification. Formation of mullite, which is a principalcompound for aluminous refractories, is evidenced in thepowders with DTA tests and for the fired samples with XRD; thefired samples are dominated by mullite peaks. Keywords: kaolin; clay; powders characterization; ceramics;mullite; Lake Victoria region;NR 2014080

Properties of Ugandan minerals and fireclay refractories

Development of products which can be produced from a country’s natural resources is very important as far as the industrialization of a nation and saving foreign exchange is concerned. Presently, industries in Uganda and the other states in the Lake Victoria region import all refractory-related-consumables, as the demand cannot be met locally. Based on the abundance of ceramic raw materials for high temperature applications in the region and the demand for refractories by industries it is pertinent to develop and manufacture firebricks by exploiting the locally available raw materials. This thesis thus, concerns the characterisation of ceramic raw mineral powders from the Lake Victoria region, more particularly, Uganda, with the aim of developing firebrick refractories from the minerals. Two main deposits of kaolin and a ball clay deposit were investigated to assess their potential in the manufacture of refractory bricks. Raw- and processed sample powders were investigated by means of X-ray diffraction (XRD), thermal analysis (DTA-TG) and Scanning Electron Microscopy (SEM). In addition, the chemical composition, particle size distribution, density, and surface area of the powders were determined. A comprehensive study on beneficiation of Mutaka kaolin was carried out using mechanical segregation of particles. The aim of the study was to explore other potential applications like in paper filling and coating. The beneficiation process improves the chemical composition of kaolin to almost pure, the major impurity being iron oxide. A general production process scheme for manufacturing fireclay bricks starting with raw powder minerals (Mutaka kaolin and Mukono ball clay) was used to make six groups of sample fireclay brick. Experimental results from the characterization of formulated sample bricks indeed revealed the viability of manufacturing fireclay bricks from the raw minerals. Based on these results, industrial samples were formulated and manufactured at Höganäs Bjuf AB, Sweden. Kaolin from the Mutaka deposit was used as the main source of alumina while ball clay from Mukono was the main plasticizer and binder material. The formulated green body was consolidated by wet pressing and fired at 1350°C in a tunnel kiln. Characterization of the sintered articles was done by X-ray diffraction, scanning electron microscopy, and chemical composition (ICP-AES). In addition, technological properties related to thermal conductivity, thermal shock, alkali resistance, water absorption, porosity, shrinkage, permanent linear change (PLC), linear thermal expansion, refractoriness under load (RUL), and cold crushing strength were determined. The properties of the articles manufactured from the selected naturally occurring raw minerals reveal that the produced articles compare favourably with those of parallel types. Thus, the raw materials can be exploited for industrial production.QC 2010102

The critical techno-economic aspects for production of B10 biodiesel from second generation feedstocks: a review

Global energy demand continues to increase owing to advancements in key growth sectors of Economies. Transportation-related emissions resulting from petroleum use account for 23% of total energy-related CO2 emissions. Biofuels including biodiesel are renewable substitutes for transportation fuels that have attracted global interest. This paper reviewed existing literature on technological, economic, and life cycle environmental aspects vital for assessment of the viability of production of second-generation biodiesel including the B10 blend advocated for Uganda. The quantity of biodiesel required to fulfil a B10 blend for Uganda’s downstream petroleum sector is one hundred million litres per annum. To meet this demand, 50,000 ha of land is required for cultivation of biodiesel feedstocks against the available 6,900,000 ha. Jatropha, castor, and croton, offer agronomical advantages. Biodiesel produced from these feedstocks through transesterification, should conform to ASTM D6751/EN14214 standards. Physicochemical, economic, and environmental assessments are vital to confirm its techno-economic viability