Eco-Friendly Use of Guinea Corn Straw as Building Material in Construction for Sustainable Development

Globally, million tonnes of straws are produced annually from farms as agricultural wastes. Walls made from plastered straw bale blocks are known to have low thermal conductivity and provide insulation for houses when used in building construction. In this study, the use of guinea corn straw encapsulated in cement mortar to produce masonry units for construction of building was carried out.The baled straws were manually compressed and tightly bound with twine purposely to avoid looseness, thus increasing the density of bale. Construction of wooden moulds of inner sizes of 150mm x 200mm x 400mm for straw brick blocks was adopted catering for mortar thickness of 50mm as cover for adequate protection of the baled straw encased. The average compressive strength of mortar used was determined, the density and strength of the resulting masonry units were also determined. A prototype building of plan dimension 5000 mm x 3000 mm was constructed with the use of straw brick blocks. The average compressive strength of the mortar was 11.11N/mm2, the density and strength of the straw bale block was found to be 62.86 kg/m3 and 1.87N/mm2 respectively. These values meet the minimum specification outlined in BS5628-1:1992 for masonry unit standard for building construction. The cost of producing a square meter of wall with straw block was compared with that of the conventional sandcrete block. The comparison showed that the use of straw block in wall construction reduced the cost of producing blocks by almost 35%. Keywords: straw bale, straw block, compressive strengt

Strength and Workability Improvement Potential of Admixture of Corn Cob Ash and Cement for Stabilizing Lateritic Soil

A natural lateritic soil classified as A-7-5 (10) and CL based on AASHTO and USCS classification systems, was stabilized with up to 5% cement admixed with up to 12% CCA to assess their effect on its basic geotechnical properties such as particle size distribution, Atterberg limits, compaction, unconfined compressive strength and California bearing ratio. The liquid limit decreased and plastic limit increased while there is a reduction in corresponding plasticity index of the clay soil. There was an increase in Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) of the stabilized soil sample, which increased with the increasing content of CCA and cement. Both the Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR) of the soil increased with increasing percentage of cement and CCA. Based on the results of this study, corn cob ash (CCA) cannot be used as a stand-alone stabilizer for this lateritic soil but with a more potent stabilizer for clay soil such as lime. It is therefore recommended that the mixture of 12% CCA and 2.5% cement could be used to stabilize A-7-5 (10) lateritic soil for use as subbase material and 12% CCA and 5.0% cement could be used to stabilize A-7-5 (10) lateritic soil for use as base material for improving pavement structure in terms of strength, stability and workability. Keywords: Lateritic soil, Corn cob ash, Cement, Stabilization, Strength and Workability DOI: 10.7176/JIEA/9-7-06 Publication date: December 31st 201

Building the capacity to solve complex health challenges in Sub-Saharan Africa : CARTA’s multidisciplinary PhD training

Objectives: To develop a curriculum (Joint Advanced Seminars- JAS) that produced PhD fellows who understood that health is an outcome of multiple determinants within complex environments and that approaches from a range of disciplines is required to address health and development within the Consortium for Advanced Research Training in Africa. We sought to attract PhD fellows, supervisors and teaching faculty from a range of disciplines into the program. Methods: Multidisciplinary teams developed the JAS curriculum. CARTA PhD fellowships were open to academics in consortium member institutions, irrespective of primary discipline, interested in doing a PhD in public and population health. Supervisors and JAS faculty were recruited from CARTA institutions. We use routine JAS evaluation data (closed and open ended questions) collected from PhD fellows at every JAS, a survey of one CARTA cohort and an external evaluation of CARTA to assess the impact of the JAS curriculum on learning. Results: We describe our pedagogic approach arguing its centrality to an appreciation of multiple disciplines and illustrate how it promotes working in multidisciplinary ways. CARTA has attracted PhD fellows, supervisors and JAS teaching faculty from across a range of disciplines. Evaluations indicate PhD fellows have a greater appreciation of how disciplines other than their own are important to understand health and its determinants and an appreciation and capacity to employ mixed methods research. Conclusions: In the short-term, we have been effective in promoting an understanding of multidisciplinarity resulting in fellows using methods from beyond their discipline of origin. This curriculum has international application

THE COMBINED EFFECTS OF SOIL, WATER AND SURCHARGE LOADS ON THE STRUCTURAL BEHAVIOURS OF CANTILEVER RETAINING WALL

Retaining walls are engineering structures constructed to resist lateral forces imposed by soil movement and water pressure; they are used as protection against the erosive forces of water and as a method of slope stabilization along highways, railroads and construction sites. This Study modeled the combined effects of soil, Surcharge loads and Hydrostatic pressure on the structural behaviours of cantilever retaining wall under varying geometric conditions. The limit state requirements for overturning, sliding and bearing pressure were studied under different geometric properties. The use of computer programming (Java) was employed for quick analyses of the conditions. This research therefore minimized the stress associated with the iterative process of design and analyses of these structures. The deductions gave range of satisfactory dimensions with respect to the height of the wall for the preliminary dimensioning state of design. This study also answered the remained unanswered question of the effects of an increasing load being supported by retaining wall. The results revealed that Cantilever retaining wall will perform satisfactorily based on the factors of safety of and as against sliding and overturning respectively if soil is ignored in front of the wall with following values of Base width: For wall supporting full submerged soil, the Base width, ; wall supporting submerge soil up to 0.6 of its Height, Base width,   and for wall with submerge soil up to 0.2 of wall height, Base width, . Results also showed that safety factors against sliding and overturning increase at a decreasing rate with constant decrease in water level. This gives an indication that water level greatly affects the stability of the retaining wall, that is, the higher the water level the greater the sliding and overturning effects. Results also revealed that sliding safety factor increases constantly with Base width while factor of safety against overturning increases at an increasing rate. This also shows the severity of sliding as against overturning. Both safety factors also increase at a decreasing rate with Wall height giving an indication that the stability of cantilever retaining wall increases with its Height under the same load. For an increasing surcharge values, sliding safety factor decreases constantly while overturning decreases at a decreasing rate. This also explains why overturning is less critical as compared to sliding effect

CHEMICAL COMPOSITION OF SOLID MINERALS FROM LOKOJA AND JOS IN NORTH CENTRAL NIGERIA

The structural, qualitative and quantitative analysis of grained rock samples were carried out with the view to establishing the mineral components present in the samples. Two samples were collectedfrom a mining site in Jos, Plateau State as well as from another mining site in Lokoja, Kogi State.The two samples were prepared for XRD analysis using a backloading preparation method and done with X-ray diffractometer. The analysis confirmed the presence of minerals such as Cassiterite (SnO2), Ilmenite (FeTiO3), Zircon (SiO4),Columbite (Fe), Manganoan in the ample from Jos as a result of the matching of the peaks with the database 2θ values. The percentage area integration of the various phases which correlated to the quantity of the various minerals in the sample revealed that Cassiterite(Tin Oxide) of 65.9% value was from Jos and is a Tin Ore. The grain sizes for Cassiterite (SnO2), Ilmenite (FeTiO3), Zircon (SiO4), Columbite (Fe), Manganoan are 17.674, 35.348, 37.208, 70.695, 20.199 in nm respectively. The samples from Lokoja showed the presence of Magnetite (Fe¬3O4), Quartz (SiO2), Hematite (Fe2O3) and Geothite(FeO(OH)) and confirmed the grain sizes of 28.278, 35.348, 28.278. 17.673 and 23.565 in nm respectively.The constituents of Lokoja samples, all of which contained Iron Oxide also indicate that the sample is an Iron Ore. These findings confirm the fact that the mineral resources that are present in these regions of the country areeconomically viable and have the potential to boost economy and industrial development&nbsp

ECONOMIC ANALYSIS OF DIFFERENT WOOD SPECIES IN MAJOR SAWMILLS IN ABEOKUTA OGUN STATE NIGERIA

This study involved the economic analysis of different wood species in major sawmills in Abeokuta, Ogun State Nigeria. Two stage design sampling techniques were employed for this study. Descriptive statistics and Cost and Returns were used in the data analysis. Result showed that 62.5% engaged in the business were males, 81.7% were in age group between 31-50years, 48.3% had no formal education, and 88.3% entered into the business through apprenticeship and are mostly full-time. The result also revealed that 95.83% of the saw millers or plank sellers obtain their timber from the private forest and they mostly buy per species i.e. per tree. Moreover, among the timber species that were common in the saw mills include, Albizia coriaria (ayinre) has the highest percentage frequency of 66.7%, Anogeissus leiocarpus (orin dudu) has 44.2%, Cleistopholis sp. (okedo) 32.5% and Musanga cecropioides (aga) 1.7% with the least percentage frequency. Average girth sizes of timber species in sawmill, ranged from 3.00cm- 5.60cm and the average number of plank ranged from 6-29. The business could be seen as profitable, as the cost analysis revealed the average profit for each sawmill per month  in Abeokuta North, Odeda and Abeokuta South Local Governments’ Areas to have these profits (₦982,893.75, ₦790,083.524 and ₦790,083.524) respectively. It was recommended that government policy should be reviewed against illegal felling and over-exploitation of timber by imposing/enacting stiffer penalty or law to illegal feller. Government policy should also encourage individual plantation establishment to ensure continuity of forest products for posterity. &nbsp

Evaluation of Composition, Microstructure Characterization and Interfacial Properties of Zn–SnO2 Metal Matrix Composite Coating

In this paper the microstructure and tribological behavior of Zn–SnO2 (Zn–Sn) alloys produced through chloride and sulphates co-deposition is presented for comparison. 7.0 wt % SnO2 was added to Zn bath and deposited at 0.3 V. The interfacial effect and microchemistry of the fabricated composite was studied by optical microscope, X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy disperse spectrum (EDS). The tribological behavior of the metal composites with SnO2 particles as reinforcement was studied using reciprocating sliding tester. The scanning electron microscopy (SEM) and atomic force microscope (AFM) of the composite surfaces indicates that there is good interfacial interaction between the alloy formulated matrixes made from the two baths and the substrate. Reasonable uniform distribution of Sn metal phase particulates is shown for both coating alloy. Increases in hardness and wear resistance are attributed to the uniform and coherent precipitation in the metal interface especially for Zn–7Sn–S–0.3V. In general, 7 wt % Sn additions to the bath showed more hastening to improved surface properties and better mechanical characteristics

Ustekinumab as Induction and Maintenance Therapy for Crohn’s Disease

BACKGROUND Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin-12 and inter-leukin-23, was evaluated as an intravenous induction therapy in two populations with moderately to severely active Crohn’s disease. Ustekinumab was also evaluated as subcutaneous maintenance therapy. METHODS We randomly assigned patients to receive a single intravenous dose of ustekinumab (either 130 mg or approximately 6 mg per kilogram of body weight) or placebo in two induction trials. The UNITI-1 trial included 741 patients who met the criteria for primary or secondary nonresponse to tumor necrosis factor (TNF) antagonists or had unacceptable side effects. The UNITI-2 trial included 628 patients in whom conventional therapy failed or unacceptable side effects occurred. Patients who completed these induction trials then participated in IM-UNITI, in which the 397 patients who had a response to ustekinumab were randomly assigned to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 8 weeks or every 12 weeks) or placebo. The primary end point for the induction trials was a clinical response at week 6 (defined as a decrease from baseline in the Crohn’s Disease Activity Index [CDAI] score of ≥100 points or a CDAI score <150). The primary end point for the maintenance trial was remission at week 44 (CDAI score <150). RESULTS The rates of response at week 6 among patients receiving intravenous ustekinumab at a dose of either 130 mg or approximately 6 mg per kilogram were significantly higher than the rates among patients receiving placebo (in UNITI-1, 34.3%, 33.7%, and 21.5%, respectively, with P≤0.003 for both comparisons with placebo; in UNITI-2, 51.7%, 55.5%, and 28.7%, respectively, with P<0.001 for both doses). In the groups receiving maintenance doses of ustekinumab every 8 weeks or every 12 weeks, 53.1% and 48.8%, respectively, were in remission at week 44, as compared with 35.9% of those receiving placebo (P = 0.005 and P = 0.04, respectively). Within each trial, adverse-event rates were similar among treatment groups. CONCLUSIONS Among patients with moderately to severely active Crohn’s disease, those receiving intravenous ustekinumab had a significantly higher rate of response than did those receiving placebo. Subcutaneous ustekinumab maintained remission in patients who had a clinical response to induction therapy. (Funded by Janssen Research and Development; ClinicalTrials.gov numbers, NCT01369329, NCT01369342, and NCT01369355.

Evaluation of sesamum gum as an excipient in matrix tablets

In developing countries modern medicines are often beyond the affordability of the majority of the population. This is due to the reliance on expensive imported raw materials despite the abundance of natural resources which could provide an equivalent or even an improved function. The aim of this study was to investigate the potential of sesamum gum (SG) extracted from the leaves of Sesamum radiatum (readily cultivated in sub-Saharan Africa) as a matrix former. Directly compressed matrix tablets were prepared from the extract and compared with similar matrices of HPMC (K4M) using theophylline as a model water soluble drug. The compaction, swelling, erosion and drug release from the matrices were studied in deionized water, 0.1 N HCl (pH 1.2) and phosphate buffer (pH 6.8) using USP apparatus II. The data from the swelling, erosion and drug release studies were also fitted into the respective mathematical models. Results showed that the matrices underwent a combination of swelling and erosion, with the swelling action being controlled by the rate of hydration in the medium. SG also controlled the release of theophylline similar to the HPMC and therefore may have use as an alternative excipient in regions where Sesamum radiatum can be easily cultivated