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

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

Causal ambiguity in lean production implementation in Malaysia

The success of the lean production system in Japan has led other companies to attempt to adopt it. Yet lean production system initiatives have seen a low success rate. This study draws on the theory of causal ambiguity and its role in the transfer of knowledge to argue that causal ambiguity can impede interfirm transfer of knowledge during lean production system implementation. The authors argue that causal ambiguity undermines motivation during lean production system implementation. Several variables are proposed as moderating the relationship. The findings of a survey are presented here

Penerokaan Potensi Modul Permainan Peribahasa ADDIE terhadap Penguasaan Penulisan Rumusan dalam Talian Google Meet dan E-mel

Pandemik Covid-19 yang melanda seantero dunia telah menyebabkan wujudnya amalan pembelajaran dan pengajaran (PdP) norma baharu. Pembelajaran murid yang dilaksanakan secara maya seperti penggunaan talian Google Meet dan penghantaran latihan menerusi e-mel misalnya telah memberi implikasi terhadap keupayaan murid menerima ilmu pengetahuan. Justeru, penyelidik telah membina Modul Permainan Peribahasa ADDIE sebagai pendekatan untuk meningkatkan kemahiran penulisan rumusan murid. Penggunaan modul ini dilihat mempunyai potensi dalam usaha membantu guru mengatasi masalah pengabaian aspek seni bahasa dalam penulisan di samping untuk menjimatkan masa lantaran kelangsungan proses penambahbaikan berasaskan maklum balas berjalan serentak. Objektif kajian ini bertujuan untuk meneroka keterlibatan murid terhadap penggunaan Modul Permainan Peribahasa ADDIE untuk meningkatkan seni bahasa dalam penulisan rumusan. Kaedah penyelidikan ini berbentuk kajian kes kualitatif yang menggunakan tiga teknik pengumpulan data. Tiga teknik pengumpulan data ini merangkumi pemerhatian, temu bual separa struktur, dan analisis dokumen digunakan untuk menentukan objektif dan dapatan kajian tercapai. Seramai 35 orang murid Tahun Lima berpencapaian sederhana di sebuah sekolah rendah di Selangor dipilih sebagai peserta kajian manakala enam orang murid pula dipilih untuk ditemu bual. Teknik pemerhatian dalam bilik darjah dilakukan dengan melibatkan penggunaan modul sebanyak 12 sesi PdP melalui talian Google Meet sebagai media pembelajaran. Dapatan kajian menunjukkan komunikasi dua hala antara guru dan murid telah berlangsung dengan baik. Buktinya, analisis penghantaran latihan melalui e-mel menunjukkan terdapat Perubahan positif terhadap aspek seni bahasa dalam penulisan rumusan. Oleh itu, penggunaan Modul Permainan Peribahasa ADDIE melalui talian Google Meet dapat dijadikan bahan rujukan pembelajaran norma baharu bagi membantu murid menulis rumusan

Design and Implementation of the Ulul Albab Teacher Training Program at Imtiaz Schools in Malaysia

Ulul Albab education is an education that offers in selected secondary schools in Malaysia. In the context of the teachers at the Ulul Albab schools, the in-service program is essential as the existing pre-service programs do not directly focus on the concept of Ulul Albab education. This qualitative study aims to examine the design and implementation of the Ulul Albab teacher training program at Imtiaz secondary schools. This qualitative study employed the case study method by interviewing six participants using a purposive sampling technique consisting of Ulul Albab program coordinators, Imtiaz secondary school principal, and four teachers at Imtiaz secondary schools who performed Ulul Albab programs. The findings showed that there are several designs of teacher training programs such as Quranic culture, explanation of school mission, benchmarking visits to excellent schools, and the emphasis on holistic education concept. The findings of the study also indicate that the implementation of teacher training programs should be carried out periodically, and consistently by the school and relevant departments. This study has important implications for professional development programs for Ulul Albab teachers during their services, especially on the aspects that have been highlighted in the study findings

Optimization of Bio-Foamed Concrete Brick Strength via Bacteria Based Self-Healing and Bio-Sequestration of CO2

This research aimed to optimize the compressive strength of bio-foamed concrete brick (B-FCB) via a combination of the natural sequestration of CO2 and the bio-reaction of B. tequilensis enzymes. The experiments were guided by two optimization methods, namely, 2k factorial and response surface methodology (RSM). The 2k factorial analysis was carried out to screen the important factors; then, RSM analysis was performed to optimize the compressive strength of B-FCB. Four factors, namely, density (D), B. tequilensis concentration (B), temperature (T), and CO2 concentration, were selectively varied during the study. The optimum compressive strength of B-FCB was 8.22 MPa, as deduced from the following conditions: 10% CO2, 3 × 107 cell/mL of B, 27 °C of T and 1800 kg/m3 of D after 28 days. The use of B. tequilensis in B-FCB improved the compressive strength by 35.5% compared to the foamed concrete brick (FCB) after 28 days. A microstructure analysis by scanning electronic microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction analysis (XRD) reflected the changes in chemical element levels and calcium carbonate (CaCO3) precipitation in the B-FCB pores. This was due to the B. tequilensis surface reactions of carbonic anhydrase (CA) and urease enzyme with calcium in cement and sequestered CO2 during the curing time

Factors Affecting Carbonation Depth in Foamed Concrete Bricks for Accelerate CO2 Sequestration

Foamed concrete bricks (FCB) have high levels of porosity to sequestrate atmospheric CO2 in the form of calcium carbonate CaCO3 via acceleration of carbonation depth. The effect of density and curing conditions on CO2 sequestration in FCB was investigated in this research to optimize carbonation depth. Statistical analysis using 2k factorial and response surface methodology (RSM) comprising 11 runs and eight additional runs was used to optimize the carbonation depth of FCB for 28 days (d). The main factors selected for the carbonation studies include density, temperature and CO2 concentration. The curing of the FCB was performed in the chamber. The results indicated that all factors significantly affected the carbonation depth of FCB. The optimum carbonation depth was 9.7 mm, which was determined at conditions; 1300 kg/m3, 40 °C, and 20% of CO2 concentration after 28 d. Analysis of variance (ANOVA) and residual plots demonstrated the accuracy of the regression equation with a predicted R2 of 89.43%, which confirms the reliability of the predicted model