Review of Maintenance Strategies For Achieving Sustainable Developments In Tropical Climates

Buildings, like almost all physical objects degrade over time due to a combination of factors. The deterioration affects all components and parts of the building in different ways, gradually reducing the quality of the structure and adversely impacting the building’s ability to effectively perform its basic functions in an environment. This paper relied on a systematic review of published literatures in reputable databases to examine how building developments and public environments can be designed in tropical climates to require minimal maintenance activities to enhance the ease of executing such activities. 39 open access published documents were reviewed. Data sieved from the publications were content analysed and descriptively presented in themes. The study identified principles and methods which can be implemented in the design of buildings with a focus on maintainability towards enhancing the development of sustainable public buildings and environments in tropical climates. The review promotes maintenance culture and emphasises increased consideration for maintenance in building design, which further helps to promote the eleventh target of the 17 Sustainable Development Goals that aims at the development of resilient, safe and sustainable communities, cities and human settlements. The paper is instructive to researchers, scholars, students of architecture and building design, as well as policy makers on issues surrounding the principles of designing for maintainability, particularly in tropical settings

Dataset of mechanical, marshall and rheological properties of crumb rubber – Bio-oil modified hot mix asphalt for sustainable pavement works

This data article presents information on the modification of bitumen with bio-oil pyrolyzed from cassava peels,and upgraded with a non-degradable polymer i.e. crumb rubber.Performance tests were carried out on the bio-oil crumb rubber modified bitumen. The main objective of bitumen modification is to produce new binders with improved mechanical,marshall and rheological properties. The percentage of bio-oil by volume used for modification of bitumen was 5%,10%,15% and 20% respectively. Marshall Stability and flow tests were also carried out on the crumb rubber bio-asphalt produced

DEVELOPMENT AND PERFORMANCE EVALUATION OF CRUMB RUBBER –BIO-OIL MODIFIED HOT MIX ASPHALT FOR SUSTAINABLE HIGHWAY PAVEMENTS

The asphalt industry has been perpetually challenged by its hazardous emissions and its contribution to the ongoingclimate change andglobal warming crises. Likewise, the environment has been cumbered by the challenge of improper disposal of non-degradable solid wastes especially crumb rubber in form of scrap tyres resulting in serious environmental degradation. This research investigated the effect of modifying bitumen with bio-oil from cassava peels upgraded with a nondegradable polymer i.e. crumb rubber. Performance tests were carried out on the modified bitumen to evaluate its effect on its rheological properties. The percentage of bio-oil by volume used for modification of bitumen was 5%, 10%, 15% and 20%. Marshall Stability and flow tests were also carried out on the bio-asphalt produced. Experimental results of bitumen modification with cassava peel oil at 5%, 10%, 15% and 20% replacements showed an increment in flash point of 244°C, 250°C, 252°C & 259°C fire point of 259°C, 265°C, 269°C & 274°C and softening point values of 55°C, 55.5°C, 56.5°C & 57.5°C respectively of the base bitumen. Due to the high moisture content associated with bio-oils, properties such as ductility and viscosity were adversely affected. Upgrading with crumb rubber caused an improvement in the engineering properties of the base bitumen with penetration grade at 20% modification showed the resultant blend was 40/50 which is suitable for use on airport pavements. The highest Marshall Stability and Flow values were obtained at 20% modification with bio-oil upgraded with polymer with values of 26.5kN and 13.33mm as against 9kN and 10.5mm obtained on the controlsample. Finally, it was observed that the bio-oil could be utilized in the production of cutback bitumen due to the reduction of viscosit

Parasite reduction ratio one day after initiation of artemisinin-based combination therapies and its relationship with parasite clearance time in acutely malarious children

Abstract Background In acute falciparum malaria, asexual parasite reduction ratio two days post-treatment initiation (PRRD2) ≥ 10 000 per cycle has been used as a measure of the rapid clearance of parasitaemia and efficacy of artemisinin derivatives. However, there is little evaluation of alternative measures; for example, parasite reduction ratio one day after treatment initiation (PRRD1) and its relationship with parasite clearance time (PCT) or PRRD2. This study evaluated the use of PRRD1 as a measure of responsiveness to antimalarial drugs. Methods In acutely malarious children treated with artesunate-amodiaquine (AA), artemether-lumefantrine (AL) or dihydroartemisinin-piperaquine (DHP), the relationships between PRRD1 or PRRD2 and PCT, and between PRRD1 and PRRD2 were evaluated using linear regression. Agreement between estimates of PCT using PRRD1 and PRRD2 linear regression equations was evaluated using the Bland-Altman analysis. Predictors of PRRD1 > 5000 per half cycle and PRRD2 ≥ 10 000 per cycle were evaluated using stepwise multiple logistic regression models. Using the linear regression equation of the relationship between PRRD1 and PCT previously generated in half of the DHP-treated children during the early study phase, PCT estimates were compared in a prospective blinded manner with PCTs determined by microscopy during the later study phase in the remaining half. Results In 919 malarious children, PRRD1 was significantly higher in DHP- and AA-treated compared with AL-treated children (P  15 months, parasitaemia > 10 000/μl and DHP treatment independently predicted PRRD1 > 5000 per half cycle, while age > 30 months, haematocrit ≥31%, body temperature > 37.4 °C, parasitaemia > 100 000/μl, PRRD1 value > 1000 and no gametocytaemia independently predicted PRRD2 ≥ 10 000 per cycle. Using the linear regression equation generated during the early phase in 166 DHP-treated children, PCT estimates and PCTs determined by microscopy in the 155 children in the later phase were similar in the same patients. Conclusions PRRD1 and estimates of PCT using PRRD1 linear regression equation of PRRD1 and PCT can be used in therapeutic efficacy studies. Trial registration Pan African Clinical Trial Registration PACTR201709002064150, 1 March 2017, http://www.pactr.or