Rice Husk as Filler in the Production of Bricks Using Gboko Clay

Rice Husk is a by-product of rice from agricultural processing which is usually disposed in landfill as waste. Farmers and rice millers normally burn the rice husk (RH)as fuel in milling which leads to air pollution. This study looked at ways of converting the husk into materials for the construction industry.  Chemical composition of RH and Gboko clay soil were investigated using X-ray diffraction test. Four grades (75, 150, 300, 425 microns) of ground rice husk were mixed with clay at 0, 2, 4, 6, 8 and 10%, by weight. The compressive strength and the lowest water absorption were determined. The chemical composition obtained for the RH showed that the total percentage compositions of Fe2O3, SiO2 and Al2O3 were found to be below 70% (class C) which is the minimum requirement for pozzolans. The compressive strength test showed that test samples of 300 μm gave the highest compressive strength of 5.47 N/ mm2 at 2% admixture with the least water absorption of 0.379%. Thus 2% of rice husk used as replacement for clay soil gave the best result. The study concluded that the use of Rice Husk as filler in production of bricks is suitable in the construction industry.http://dx.doi.org/10.4314/njt.v34i4.

Dealing With the Complexity of Effective Population Size in Conservation Practice

Effective population size (Ne) is one of the most important parameters in evolutionary biology, as it is linked to the long-term survival capability of species. Therefore, Ne greatly interests conservation geneticists, but it is also very relevant to policymakers, managers, and conservation practitioners. Molecular methods to estimate Ne rely on various assumptions, including no immigration, panmixia, random sampling, absence of spatial genetic structure, and/or mutation-drift equilibrium. Species are, however, often characterized by fragmented populations under changing environmental conditions and anthropogenic pressure. Therefore, the estimation methods' assumptions are seldom addressed and rarely met, possibly leading to biased and inaccurate Ne estimates. To address the challenges associated with estimating Ne for conservation purposes, the COST Action 18134, Genomic Biodiversity Knowledge for Resilient Ecosystems (G-BiKE), organized an international workshop that met in August 2022 in Brașov, Romania. The overarching goal was to operationalize the current knowledge of Ne estimation methods for conservation practitioners and decision-makers. We set out to identify datasets to evaluate the sensitivity of Ne estimation methods to violations of underlying assumptions and to develop data analysis strategies that addressed pressing issues in biodiversity monitoring and conservation. Referring to a comprehensive body of scientific work on Ne, this meeting report is not intended to be exhaustive but rather to present approaches, workshop findings, and a collection of papers that serve as fruits of those efforts. We aimed to provide insights and opportunities to help bridge the gap between scientific research and conservation practice

Dealing With the Complexity of Effective Population Size in Conservation Practice

ABSTRACTEffective population size (Ne) is one of the most important parameters in evolutionary biology, as it is linked to the long‐term survival capability of species. Therefore, Ne greatly interests conservation geneticists, but it is also very relevant to policymakers, managers, and conservation practitioners. Molecular methods to estimate Ne rely on various assumptions, including no immigration, panmixia, random sampling, absence of spatial genetic structure, and/or mutation‐drift equilibrium. Species are, however, often characterized by fragmented populations under changing environmental conditions and anthropogenic pressure. Therefore, the estimation methods' assumptions are seldom addressed and rarely met, possibly leading to biased and inaccurate Ne estimates. To address the challenges associated with estimating Ne for conservation purposes, the COST Action 18134, Genomic Biodiversity Knowledge for Resilient Ecosystems (G‐BiKE), organized an international workshop that met in August 2022 in Brașov, Romania. The overarching goal was to operationalize the current knowledge of Ne estimation methods for conservation practitioners and decision‐makers. We set out to identify datasets to evaluate the sensitivity of Ne estimation methods to violations of underlying assumptions and to develop data analysis strategies that addressed pressing issues in biodiversity monitoring and conservation. Referring to a comprehensive body of scientific work on Ne, this meeting report is not intended to be exhaustive but rather to present approaches, workshop findings, and a collection of papers that serve as fruits of those efforts. We aimed to provide insights and opportunities to help bridge the gap between scientific research and conservation practice

Dealing with the complexity of effective population size in conservation practice

Effective population size (Ne) is one of the most important parameters in evolutionary biology, as it is linked to the long‐term survival capability of species. Therefore, Ne greatly interests conservation geneticists, but it is also very relevant to policymakers, managers, and conservation practitioners. Molecular methods to estimate Ne rely on various assumptions, including no immigration, panmixia, random sampling, absence of spatial genetic structure, and/or mutation‐drift equilibrium. Species are, however, often characterized by fragmented populations under changing environmental conditions and anthropogenic pressure. Therefore, the estimation methods' assumptions are seldom addressed and rarely met, possibly leading to biased and inaccurate Ne estimates. To address the challenges associated with estimating Ne for conservation purposes, the COST Action 18134, Genomic Biodiversity Knowledge for Resilient Ecosystems (G‐BiKE), organized an international workshop that met in August 2022 in Brașov, Romania. The overarching goal was to operationalize the current knowledge of Ne estimation methods for conservation practitioners and decision‐makers. We set out to identify datasets to evaluate the sensitivity of Ne estimation methods to violations of underlying assumptions and to develop data analysis strategies that addressed pressing issues in biodiversity monitoring and conservation. Referring to a comprehensive body of scientific work on Ne, this meeting report is not intended to be exhaustive but rather to present approaches, workshop findings, and a collection of papers that serve as fruits of those efforts. We aimed to provide insights and opportunities to help bridge the gap between scientific research and conservation practice

Application of yield line theory in pre-cast waffle slab

Analysis of precast waffle slabs have concentrated on the rib portions, while the slab portion were left unanalyzed. This has led to cracks or outright failure of the slab portions due to under reinforcement. This paper proposed the use of yield line theory in solving this problem. Yield line theory was adopted to develop a computer program called YLRGT in the analysis of pre-cast waffle slabs. Three panels with dimensions 6m x 6m, 6m x 5m and 5m x 2m were analyzed, and the results were compared with an existing analytical method which was based on the BS 8110 slab coefficient factor. YLRGT analyzed the slab portion effectively, unlike the BS 8110 where approximate values were adopted for the slab portion. The paper concluded that the slab portion of pre-cast waffle slabs can be effectively analyzed using the computer program.Keywords: Waffle slabs, Yield line theory, Panels, YLRG

A comparative study on the strength characteristics of Grade 25 and Grade 30 rice husk ash blended cement concrete

Abstract Rice husk ash (RHA) is an agricultural waste which is a pozzolanic material that can be blended with cement in producing concrete. This research presents investigation carried out on the comparative strength characteristics of concrete produced with grade 25 and grade 30 cement blended concrete using a replacement level of 10% rice husk ash as substitute. Two mix ratios (1:2:4 and 1:1.12:3.01) were used. A total of 60 cube size of 150mm were cast, tested and their mechanical properties determined. The RHA was made in the laboratory by burning the husk obtained from Ifo in Ogun State Nigeria using an Electric furnace, with the temperatures of the furnace at about 700°C. The results showed that the compressive strength at 28 days decreased as the percentage replacement of Portland Limestone cement (PLC) with RHA increased from 0% to 10% respectively with compressive strengths of 29.78 N/mm2 to 21.56 N/mm2 for grade 25 concrete and 32.12 N/mm2 to 26.82 N/mm2 for grade 30 concrete. It was concluded that RHA replacement in concrete can be used for the production of concrete for light structural works in the development of sustainable and green structures.</jats:p

Solutions based on thermoelectric refrigerators in humanitarian contexts

In humanitarian and refugees contexts, to give an adequate quality of life to people living in emergency conditions, energy supply is very important to face with the main problems concerning food cooking and food preservation. The traditional vapour compression refrigerators have relatively high efficiency, but they may have a critical impact on the electric supply system. For this reason, new solutions with thermoelectric refrigerators are emerging; in spite of lower efficiency, they may be more compatible with proper operation of the electrical grid. Furthermore, thermoelectric refrigerators can be used in any position, do not depend on a circulating refrigerant fluid, and are not sensitive to mechanical vibrations. These properties are useful for temporary installations that have to be moved from time to time – typical conditions for some humanitarian camps – and to avoid the use of toxic or flammable refrigerant. This paper addresses the electrical characteristics of a thermoelectric refrigerator connected to the power grid in a microgrid-like installation. A sustainable solution, in which the thermoelectric refrigerator is connected to a microgrid powered by a photovoltaic plant and equipped with an electric storage system, is designed and simulated