17 research outputs found

    Pengetahuan, kemahiran dan amalan guru membina item kemahiran berfikir aras tinggi (KBAT) dalam instrumen pentaksiran pembelajaran

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    Kajian ini dijalankan bagi mengenal pasti tahap pengetahuan, kemahiran dan amalan guru membina item kemahiran berfikir aras tinggi (KBAT) dalam instrumen pentaksiran pembelajaran. Kajian ini juga melihat perbezaan tahap pengetahuan, kemahiran dan amalan guru membina item KBAT berdasarkan kepada kumpulan guru mengajar matapelajaran tingkatan 3 dan kumpulan guru mengajar matapelajaran tingkatan 5. Sebanyak enam persoalan kajian telah dibangunkan bagi mengkaji permasalahan kajian. Rekabentuk kajian ini melibatkan analisis deskriptif dan inferensi dalam bentuk tinjauan yang melibatkan data kuantitatif dengan menggunakan borang soal selidik berskala likert lima mata sebagai instrumen kajian. Seramai 161 sampel guru daripada 3 buah sekolah di daerah Muar, Johor terpilih menjadi responden dalam kajian ini. Model Pengukuran Rasch telah digunakan bagi menentukan kesahan dan kebolehpercayaan instrumen kajian yang telah dibina sendiri. Hasil analisis kajian menunjukkan tahap pengetahuan, kemahiran dan amalan guru membina item KBAT adalah berada pada tahap tinggi. Dapatan kajian juga menunjukkan tidak terdapat perbezaan yang signifikan di antara kumpulan guru mengajar matapelajaran tingkatan 3 dan kumpulan guru mengajar matapelajaran tingkatan 5 terhadap tahap pengetahuan, kemahiran dan amalan membina item KBAT. Hasil kajian ini dapat dijadikan sebagai satu garis panduan kepada guru-guru yang mengubal item pentaksiran dan program peningkatan profesionalisme guru di sekolah. Kajian lanjutan juga boleh dilaksanakan bagi memperbaiki kekurangan dalam kajian ini

    A systematic review on bio-sequestration of carbon dioxide in bio-concrete systems: a future direction

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    The paper reviewed the current perspectives on the development of carbon diox�ide (CO2) sequestration through its process conversion into calcite. The process occurs in either geological or biological systems. However, geological sequestration is an expensive process, which is slow in comparison to bio-sequestration. Recently, the bio-sequestration of atmospheric CO2 into the soil using microorgan�isms such as algae has been investigated. However, the algae cannot be used in the bio-concrete due to their nature as phototrophic organisms. In contrast, bac�teria are the most potent organisms in bio-concrete technology. The use of bacter�ial species in the bio-aerated concrete bricks (B-ACB) and its potential to bio�sequestrate CO2 represents a future strategy to reduce high CO2 pollution. Bacterial cells can capture CO2 by accelerating the carbonation processes, which convert CO2 into calcium carbonate (CaCO3) via carbon anhydrase and urease enzymes. The present paper aimed to highlight and discuss the applicability of bacteria in the B-ACB for capturing and storing CO2. It is evident from the literature that the new trends to use bio-concrete might contribute to the reduction of CO2 by accelerating the carbonation process and strengthening the B-ACB

    Review on carbonation study of reinforcement concrete incorporating with bacteria as self-healing approach

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    This study carried out a comprehensive review to determine the carbonation process that causes the most deterioration and destruction of concrete. The carbonation mechanism involved using carbon dioxide (CO2 ) to penetrate the concrete pore system into the atmosphere and reduce the alkalinity by decreasing the pH level around the reinforcement and initiation of the corrosion process. The use of bacteria in the concrete was to increase the pH of the concrete by producing urease enzyme. This technique may help to maintain concrete alkalinity in high levels, even when the carbonation process occurs, because the CO2 accelerates to the concrete and then converts directly to calcium carbonate, CaCO3 . Consequently, the self-healing of the cracks and the pores occurred as a result of the carbonation process and bacteria enzyme reaction. As a result of these reactions, the concrete steel is protected, and the concrete properties and durability may improve. However, there are several factors that control carbonation which have been grouped into internal and external factors. Many studies on carbonation have been carried out to explore the effect of bacteria to improve durability and concrete strength. However, an in-depth literature review revealed that the use of bacteria as a self-healing mechanism can still be improved upon. This review aimed to highlight and discuss the possibility of applying bacteria in concrete to improve reinforcement concrete

    Effects of Milling Time on Nano Rice Husk Ash Particle Size

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    This research focuses on the manufacture of nano Rice Husk Ash (nRHA) by ball milling technique and critically analyzes the effect of milling time on particle size. The process starts with collection of raw rice husk from a local rice mill factory, followed by controlled incineration at a temperature of 700°C for 5 hours to get the amorphous RHA. Finally, the nano RHA is prepared by subjecting the RHA to grinding for the different period like 10, 20, 30, and 40 hrs. The particle size was analyzed with FESEM, and it was found that particles got smaller as grinding proceeded, reaching an optimal size of 28 nm following 30 h grinding. Nonetheless, prolonged grinding resulted into particle agglomeration that was caused by Van der Waal forces. Therefore, these findings are significant in that they help to comprehend the morphology changes and particle size alterations in nRHA that may be applied for different uses such sustainable construction materials

    A Systematic Review of the Concrete Durability Incorporating Recycled Glass

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    This systematic literature review (SLR) aims to present and analyze the recent research on the effect of recycled glass (RG) on the durability of concrete applications in terms of transport properties, chemical attack, alkali-silica reaction (ASR), and freeze/thaw (FT). RG could be utilized in concrete as a replacement or addition in three forms, namely glass powder (GP), glass aggregate (GA), and glass fiber (GF). The methodology of this study was based on a criterion for the selection process of reviewed studies to assess and synthesize the knowledge of the durability of RG in concrete. The articles were assessed and screened, then 114 review articles were selected. The direction of utilization of RG in concrete depends on the type, particle size, and pozzolanic performance. The valorization of RG had a positive impact on the durability of concrete; however, the mutual synergy of multiple substitutions with glass also had better results. Nowadays, fine glass aggregate (FGA) could be promoted to be used as a partial substitute for sand due to the easiness of recycling. Furthermore, GF is strongly encouraged to be used in fiber concrete. An analytical framework that highlights the durability improvement of glass-modified concrete is presented. The results suggested that it is technically feasible to utilize glass as a part of concrete in the production of durable concrete. It provides a higher resistance to transport properties and chemical attacks by providing an extended lifespan. In addition, RG plays a great role in FT action in cold climates while it does not have a significant impact on ASR, provided refinement of glass results in the reduction of ASR and thus overcomes the expansion and cracks of concrete. However, up to 20% GP and up to 30% fine glass aggregate (FGA) could be replaced with cement and aggregate, respectively, to achieve a positive effect on durability based on the W/C ratio provided, not compromising the strength

    Influence of Ureolytic Bacteria Toward Interlocking Compressed Earth Blocks (ICEB) in Improving Durability of ICEB

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    Interlocking compressed earth blocks (ICEB) are soil stabilized based blocks that allows for mortarless construction. Various studies have been conducted to improve the durability of bricks by using environmental friendly solution. This is because common method used by the construction industries generally involving the use of chemical based substances which will promote pollution to the surrounding. This paper provide the results of Ureolytic Bacteria (UB) in improving the compressive strength and water absorption properties with the percentage of 1%, 3% and 5% UB for 7th ,14th and 28th days of testing. The bacteria were added as partial replacement of limestone water in ICEB. The results of compressive strength and water absorption show that the increment of 15.25% strength and reduction of 15.66% water absorption with 5% of UB on the 28th days of testing compared to the control specimen. Therefore it is hoped that the positive results on using bacteria will continue to improve the durability of the ICEB as one of the environmental friendly solution in order to achieve sustainable construction

    Influence of Ureolytic Bacteria Toward Interlocking Compressed Earth Blocks (ICEB) in Improving Durability of ICEB

    No full text
    Interlocking compressed earth blocks (ICEB) are soil stabilized based blocks that allows for mortarless construction. Various studies have been conducted to improve the durability of bricks by using environmental friendly solution. This is because common method used by the construction industries generally involving the use of chemical based substances which will promote pollution to the surrounding. This paper provide the results of Ureolytic Bacteria (UB) in improving the compressive strength and water absorption properties with the percentage of 1%, 3% and 5% UB for 7th ,14th and 28th days of testing. The bacteria were added as partial replacement of limestone water in ICEB. The results of compressive strength and water absorption show that the increment of 15.25% strength and reduction of 15.66% water absorption with 5% of UB on the 28th days of testing compared to the control specimen. Therefore it is hoped that the positive results on using bacteria will continue to improve the durability of the ICEB as one of the environmental friendly solution in order to achieve sustainable construction

    Enablers for integrated operations diagnosis and improvement

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    In order for organizations to improve their performance, they shall identify their operations opportunities for improvement. The process to identify the opportunities for improvement is referred herein as “diagnosis” process. The most common systematic operations diagnosis and improvement approaches are Quality Audit, Organizational Assessment based on Business Excellence Framework and Project Selection for Lean and Six Sigma. All these three approaches should be integrated in order to grasp the fruitful benefits for the organizations. The benefits include; minimize redundancies, improve the operations performance and eventually assist in achieving certification and award. This paper proposes the enablers for operations diagnosis and improvement based on integration of ISO19011 Quality Audit framework, Business Excellence Framework and Lean Six Sigma approaches

    A Systematic Review of the Concrete Durability Incorporating Recycled Glass

    No full text
    This systematic literature review (SLR) aims to present and analyze the recent research on the effect of recycled glass (RG) on the durability of concrete applications in terms of transport properties, chemical attack, alkali-silica reaction (ASR), and freeze/thaw (FT). RG could be utilized in concrete as a replacement or addition in three forms, namely glass powder (GP), glass aggregate (GA), and glass fiber (GF). The methodology of this study was based on a criterion for the selection process of reviewed studies to assess and synthesize the knowledge of the durability of RG in concrete. The articles were assessed and screened, then 114 review articles were selected. The direction of utilization of RG in concrete depends on the type, particle size, and pozzolanic performance. The valorization of RG had a positive impact on the durability of concrete; however, the mutual synergy of multiple substitutions with glass also had better results. Nowadays, fine glass aggregate (FGA) could be promoted to be used as a partial substitute for sand due to the easiness of recycling. Furthermore, GF is strongly encouraged to be used in fiber concrete. An analytical framework that highlights the durability improvement of glass-modified concrete is presented. The results suggested that it is technically feasible to utilize glass as a part of concrete in the production of durable concrete. It provides a higher resistance to transport properties and chemical attacks by providing an extended lifespan. In addition, RG plays a great role in FT action in cold climates while it does not have a significant impact on ASR, provided refinement of glass results in the reduction of ASR and thus overcomes the expansion and cracks of concrete. However, up to 20% GP and up to 30% fine glass aggregate (FGA) could be replaced with cement and aggregate, respectively, to achieve a positive effect on durability based on the W/C ratio provided, not compromising the strength

    Application of a novel nanocomposites carbon nanotubes functionalized with mesoporous silica-nitrenium ions (CNT-MS-N) in nitrate removal: Optimizations and nonlinear and linear regression analysis

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    In recent years, the increase in the use of agricultural fertilizers in industrial development has produced poisonous inorganic ions such as nitrates in water and soil. Nitrates in drinking water which may come from nitrogen fertilizers are a potential health risk. Removal of nitrates from the environment is a big challenge. Following the series of investigation, the present study proposes the multiwall carbon nanotubes functionalized with mesoporous silica-nitrenium ions (CNT-MS-N) as a novel adsorbent for removing nitrate ions (NO3-) from aqueous solution. The ability of CNT-MS-N to remove nitrate ions from aqueous solutions was studied at different operating conditions. The maximum removal (98%) was obtained under the optimum conditions: adsorbent dosage of 70 mg and pH 7 and for initial concentration of 80 (ppm) at 30 °C for 5 h contact time. FTIR spectroscopy showed the contribution of amine, amide groups in removing nitrate and the FESEM-EDX results confirmed the adsorption of nitrate ions on the function groups of CNT-MS-N. In addition, nonlinear and linear isotherms and kinetics models were used to evaluate the equilibrium adsorption results. The coefficient of determination (R2) was used to determine the best-fit model expected by each approach. The results showed that the non-linear Langmuir isotherm model is a better way to achieve adsorption parameters illustrating the adsorption of nitrate ions onto CNT-MS-N with R2 (0.9829). Likewise, it was found that the nonlinear Pseudo-second order rate model using the non-linear regression approach better predicted experimental results with R2 (0.9921). The present investigation confirmed the nonlinear method as an appropriate technique to predict the optimum adsorption isotherm and kinetic data
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