Engineering properties of acrylic emulsion polymer modified bamboo reinforced cement bonded composites

In this study, bamboo fibres from Bambusa Vulgaris species were used as reinforcement materials for acrylic emulsion polymer modified concrete to determine their engineering properties and elemental compositions. Moisture absorption, density and percentage voids were investigated as well as the compressive strength, flexural strength and split tensile strength at 28, 45 and 60 days of air curing. Acrylic polymers reduced moisture intake, increased the densities and led to another increase in percentage of voids but composite samples with bamboo fibre inclusions at 1.5% and 10% polymers with 1.5% fibre an 15% polymers showed better physical properties than those with polymers only. Compressive and split tensile strength tests had similar results of optimum strength at 45 days while flexural strength test had optimum value at 60 days of air curing. This showed that the properties of unreinforced concrete could be improved through addition of fibres and polymers for use in structural applications

Influence of water repellent chemical additive and different curing regimes on dimensional stability and strength of earth bricks from termite mound-clay

This article is focussed on evaluating the effects of water repellent admixture and different curing regimes on characteristics of clay from termite hills used for production of earth bricks. Water absorption, thickness swelling and compressive strength characteristics of the specimens with different compositions of cement, hydrated lime and water repellent additive subjected to different curing regimes were measured. The samples were characterised by SEM and FTIR. The least water absorption was at 3.3% while thickness swelling ranged from 0.78 to 3.21 % for the samples. Saturated curing condition resulted in an average compressive strength of 35.5 N/mm2, cured curing recorded an average value of 32.9 N/mm2 while dry curing condition produced an average compressive strength of 26.9 N/mm2 and the wet curing condition resulted in 25 N/mm2. SEM characterisation of sample containing 70% termite soil, 30% cement and 0.05 Hydropruf indicated fewer voids, regular and smooth appearance in comparison with others. FTIR analysis showed distinctive broad bands at wave numbers of 3439 cm−1 for O-H stretching, and 1033.83–1008.80 cm−1 for O–H bending for all samples tested. The best performing composition in terms of the dimensional stability test was 70% termite mound clay, 10% cement, 20% hydrated lime and 0.05 Hydropruf additive. The highest mechanical strength was from composition of 70% termite mound clay, 30% cement, no hydrated lime and 0.05 Hydropruf additive. It is concluded that saturated and cured method showed better performance than the wet and dry curing regimes. The termite secretions similarly improved the clay composition in conjunction with cement, lime and chemical admixture in the internal structure of the bricks

CONSTRUCTIONOF INVERTER POWEREDLAWN MOWER

The need for the maintenance of lawns through cutting and trimming cannot be overlooked in sporting fields, residential houses, hotel, hospital and others.Furthermore; some lawns are specially bred for the sake of aesthetic.However, in some places like hospitals, special health care and rehabilitationcenters, the natural beauty of the environment is believedto contribute to a great deal in aiding the recovery and healing the mentally and physically challenged patients. This contributory effect onthe lawn has made lawn care to be involved with a great admiration. An inverter powered lawnmower was designed and constructed using the locally available materials such as a 2KVA inverter, prime mover (electric motor) of a rating of 370W, a 60Amphour battery and a 12 Voltbattery. It is of advantage over the existing ones because it uses no fuel consumption, it emits no smoke which causes air pollution, and it has no internal combustion engine to drive the motor of the machine. This lawnmower was designed to mow for a period of two (2) hours and the discharged battery can be recharged with theaid of the inverter when connected to an A.C supply.Thisstudy showed that this type of machineis most suitable in Nigeriabecause no fuel is needed to power this machine. The unit is simple, light and easy to maneuver

TRENDS, DRIVERS AND HEALTH RISKS OF ADOLESCENT FATHERHOOD IN SUB-SAHARAN AFRICA

The study examined the trends, determinants and health risks of adolescent fatherhood in countries where adolescent-girl pregnancy/motherhood are decried but with permissive male sexual latitude. Male-recode datasets of Demographic Health Survey (2000-2014) for Nigeria, Ethiopia and Zambia were used. The surveys were grouped into 3-Waves: Wave 1 (2000 and 2004); Wave 2 (2005 to 2009) and waves 3 (2010 to 2014). Ethiopia data consisted of 2000, 2005 and 2011 datasets; Nigeria‘s datasets included 2003, 2008 and 2013 while Zambia set of data featured 2002, 2007 and 2014. Wave-1 consists of 2000, 2002 and 2003 datasets; Wave-2 has 2005, 2007 and 2008 datasets while 2011, 2013 and 2014 data were used for Wave- 3. These files in each wave were grouped together and then combined into a single file. All data were weighted to ensure representation and analyses were split by countries and by waves to show the trends across .the years and for different countries. The study employed univariate, bivariate analysis and binary logistics that tested the log-odds of adolescent fatherhood with respect to selected sexual behaviour indices, individual and shared demographic variables. The results, among others, indicated that more than one out of every five adolescents has had two or more sexual partners. The likelihood of adolescent fatherhood is inversely related to condom use, but positively associated with increasing age at first cohabitation and higher number of multiple sexual partnerships (≥ 2) at odd-ratio of 1.673 and 1.769 in 2005/2009 and 2010/2014, respectively. Adolescents that have attained primary and tertiary education, and who are professionals and skilled labourers were 0.379, 0.313, 0.213 and 0.403 times (respectively) less likely to father a child as adolescent. The positive association between rural place of residence and adolescent fatherhood in the past shifted to urban residents in 2010/2014. The study concludes that enlightenment on the use of condom and testing for STIs/HIV and AIDS should be intensified. Increasing access to higher formal education including job opportunities is crucial to interventions towards boys’ vulnerability to fatherhood. The authors recommend support from policy-takers, governments and other stakeholders towards male adolescent access to higher education, skills acquisition, and campaigns against boys and girls cohabitations in the study locations and by extension sub-Saharan Africa in general

Trends, Determinants and Health Risks of Adolescent Fatherhood in Sub-Saharan Africa

BACKGROUND: This study examined the trends, determinants and health risks of adolescent fatherhood in three selected African countries where adolescent-girl pregnancy/motherhood are decried but with permissive male sexual latitude.METHODS: Adolescent male data were extracted from the malerecodedatasets of Demographic Health Survey (2000-2014) for Nigeria, Ethiopia and Zambia. The surveys were grouped into 3-Waves: (2000-2004); (2005-2008) and (2011-2014). The study employed descriptive and binary logistics that tested the log-odds of adolescent fatherhood with respect to selected sexual behaviour indices, and individual and shared demographic variables.RESULTS: The results revealed that the number of lifetimesexual-partners among the boys is ≥2. The likelihood of adolescent fatherhood is positively associated with increasing age at first cohabitation and multiple sexual partnerships (≥2) having OR=1.673 and OR=1.769 in 2005/2008 and 2011/2014 respectively. Adolescents who had attained tertiary education, and engaged in professional and skilled jobs were 0.313, 0.213 and 0.403 times (respectively) less likely to have ever-fathered a child. The positive association between rural place of residence and adolescent fatherhood in the past shifted to urban residents in 2011/2014.CONCLUSION: The study concludes that early sexual activities and cohabitation are common among male adolescents among the countries of study. The authors recommend discouragement of boy-girl cohabitation, increasing access to higher education and job opportunities in order to stem boy-fatherhood incidence in the study locations and, by extension, other countries in sub-Saharan Africa.KEYWORDS: Adolescent fatherhood, sexual behaviour, trends, determinants, health risks, lifetime-sexual-partner

Trends, Determinants and Health Risks of Adolescent Fatherhood in Sub-Saharan Africa

BACKGROUND: This study examined the trends, determinants and health risks of adolescent fatherhood in three selected African countries where adolescent-girl pregnancy/motherhood are decried but with permissive male sexual latitude. METHODS: Adolescent male data were extracted from the malerecode datasets of Demographic Health Survey (2000-2014) for Nigeria, Ethiopia and Zambia. The surveys were grouped into 3- Waves: (2000-2004); (2005-2008) and (2011-2014). The study employed descriptive and binary logistics that tested the log-odds of adolescent fatherhood with respect to selected sexual behaviour indices, and individual and shared demographic variables. RESULTS: The results revealed that the number of lifetimesexual-partners among the boys is ≥2. The likelihood of adolescent fatherhood is positively associated with increasing age at first cohabitation and multiple sexual partnerships (≥2) having OR=1.673 and OR=1.769 in 2005/2008 and 2011/2014 respectively. Adolescents who had attained tertiary education, and engaged in professional and skilled jobs were 0.313, 0.213 and 0.403 times (respectively) less likely to have ever-fathered a child. The positive association between rural place of residence and adolescent fatherhood in the past shifted to urban residents in 2011/2014. CONCLUSION: The study concludes that early sexual activities and cohabitation are common among male adolescents among the countries of study. The authors recommend discouragement of boy-girl cohabitation, increasing access to higher education and job opportunities in order to stem boy-fatherhood incidence in the study locations and, by extension, other countries in sub-Saharan Africa. Emmanuel O. Amoo , Angie Igbinoba2 , David Imhonopi3 , Olufunmilayo O. Banjo4 , Chukwuedozie K. Ajaero5 , Joshua O. Akinyemi6 , David Igbokwe7 , Lukman B. Solanke

Wastewater-based epidemiology in hazard forecasting and early-warning systems for global health risks

With the advent of the SARS-CoV-2 pandemic, Wastewater-Based Epidemiology (WBE) has been applied to track community infection in cities worldwide and has proven succesful as an early warning system for identification of hotspots and changingprevalence of infections (both symptomatic and asymptomatic) at a city or sub-city level. Wastewater is only one of environmental compartments that requires consideration. In this manuscript, we have critically evaluated the knowledge-base and preparedness for building early warning systems in a rapidly urbanising world, with particular attention to Africa, which experiences rapid population growth and urbanisation. We have proposed a Digital Urban Environment Fingerprinting Platform (DUEF) – a new approach in hazard forecasting and early-warning systems for global health risks and an extension to the existing concept of smart cities. The urban environment (especially wastewater) contains a complex mixture of substances including toxic chemicals, infectious biological agents and human excretion products. DUEF assumes that these specific endo- and exogenous residues, anonymously pooled by communities’ wastewater, are indicative of community-wide exposure and the resulting effects. DUEF postulates that the measurement of the substances continuously and anonymously pooled by the receiving environment (sewage, surface water, soils and air), can provide near real-time dynamic information about the quantity and type of physical, biological or chemical stressors to which the surveyed systems are exposed, and can create a risk profile on the potential effects of these exposures. Successful development and utilisation of a DUEF globally requires a tiered approach including: Stage I: network building, capacity building, stakeholder engagement as well as a conceptual model, followed by Stage II: DUEF development, Stage III: implementation, and Stage IV: management and utilization. We have identified four key pillars required for the establishment of a DUEF framework: (1) Environmental fingerprints, (2) Socioeconomic fingerprints, (3) Statistics and modelling and (4) Information systems. This manuscript critically evaluates the current knowledge base within each pillar and provides recommendations for further developments with an aim of laying grounds for successful development of global DUEF platforms

Development of banana fibers and wood bottom ash modified cement mortars

Many plant wastes have been generated from agriculture for years and as the current global drive towards a green-economy continues, more agro-based wastes will be generated in the future. Some of these wastes are being used presently as a form of renewable energy and result into ashes which are sent to landfills. However, previous studies have shown that ashes could be used as cement replacement while others considered the use of these agricultural wastes from plants as fiber reinforcement in cement appli-cations. In this study, an environment friendly solution was provided to replace cement with wood bot-tom ashes at 10, 15, 20 and 25% levels and modify the mortars produced with styrene butadiene polymers for improved strength. Also, as a way of providing sustainable path towards utilization of wastes from plant fibers, banana fibers were treated with alkaline solution and used to reinforce the polymer modified cement mortars. The developed cement composites were subjected to mechanical tests, microstructural, elemental, functional group and thermal conductivity analyses. It is realistic to conclude that optimum performance of the composite can be obtained when cement is replaced by up to 10% of wood bottom ash, 1.5% of banana fiber content and of 0.3% of styrene butadiene polymer emulsion The composite developed provided good thermal insulation properties and could be used in some selected cement based applications