1,721,116 research outputs found
Transforming coal bottom ash into a high-performance pozzolan: Effects of acid treatment on material properties
Full text linkThis experimental study explores the transformation of coal bottom ash (CBA), an industrial by-product, into a high-performance pozzolan to replace traditional cement in construction materials. CBA’s disposal has challenges due to its low reactivity and the risk of heavy metal leaching, which limits its sustainable reuse. To overcome these barriers, an innovative acid pre-treatment process was developed, enhancing CBA’s reactivity by removing deleterious materials and increasing silica content. Advanced characterization techniques reveal significantly lower metal content and increased silica content in the treated CBA, demonstrating its potential as a sustainable alternative. Treated CBA shows positively impacts mortar binder properties, as indicated by higher strength activity index values compared to untreated specimens. The treated CBA demonstrated a significant enhancement in mortar binder properties, achieving a 20% higher strength activity index compared to untreated samples. These findings highlight treated CBA’s potential as a sustainable and eco-friendly alternative to conventional cementitious materials. This work advances the utilization of industrial by-products in construction, promoting environmental sustainability and reducing reliance on traditional cement
Pozzolanic and strength properties of mortar containing chemically pre-treated coal bottom ash
Full text linkAn intensive research to produce highly reactive pozzolan, particularly from industrial waste, to replace the role of cement in construction material is crucial. This action would increase the recycling rate of industrial waste and, concurrently, reduce the extraction of non-renewable resources of limestone. Unique characteristic of coal bottom ash as one of the industrial based pozzolan gained less popularity because of its low reactivity and heavy metal leaching due to conventional method used for disposal. Few researches are available in the use of coal bottom ash as an alternative pozzolan. Most of the literatures discussed the functionality of it as an aggregate. Therefore, an alternative approach was deliberated in this research to safely utilized coal bottom ash by eliminate risk of leaching and enhance the quality of bottom ash as pozzolanic purpose. Pre-treatment with acid solution at various parameters was used to reduce deleterious material and impurities from the coal ash. The process begun with soaking of ash in various concentration of acid solutions with different time interval and left dried in an oven at 105ºC overnight. Coal bottom ash after the pre-treatment with optimum parameter was then undergo solutiongelification process with various alkali based solution for 2 hours soaking durations. The ash obtained was then characterized by determining its chemical oxides composition, particle size analysis, mineralogical characteristics and microstructure using x-ray fluorescence, x-ray diffraction and field emission scanning electron microscope. The effect of soluble silica was evaluated based on these properties. Various level of replacement (0-10%) was used in this study. Fresh and hardened mortar performance was evaluated via compressive strength, porosity, heat of hydration, thermogravimetry and microstructure analysis. The treated ash obtained with optimum parameters has exhibited significantly lower amount of metals. The amounts of metals leached out correlates with the significant increment of silica content compared with raw ash. Transformation of treated CBA into soluble form has offered a positive contribution to the properties of mortar binder in cementitious system which was evidenced by strength activity index value than untreated and treated mortar specimen. In this study, 5% of soluble silica was found as the optimum cement replacement that shows significant strength increment from early and later age. Refinement of microstructure after soluble silica inclusion by secondary Calcium- Silicate- Hydrate (C-S-H) was found scattered on the surface of cement particles with compact and reticular microstructure closely interweaving with each other in forming continuous structure. This microstructure reformation have effectively strengthen the bonding and filled the micro pores of cement matrix and improved the macro strength performance. Statistical analysis using pearson correlation coefficients shows the potentially important correlation between the compressive strength performances and the independent variables of porosity, addition of silica content, surface area, unit weight and higher removal of aluminum oxide. From this study, coal bottom ash shows a positive prospect to be developed as an alternative pozzolan after pre-treatment process. It would also assist in the green disposal of this scheduled waste
MEMUPUK KEMAHIRAN BERFIKIR SECARA BERSEPADU DI PERINGKAT SEKOLAH
No full textKertas kerja ini bertujuan untuk meninjau keperluan untuk memupuk kemahiran berfikir secara bersepadu dalam kalangan murid di peringkat mikro. Kajian ini menggunakan kaedah analisis secara kritikal dan konseptual. Kementerian Pelajaran Malaysia (2013) menggesa supaya setiap murid perlu menguasai pelbagai kemahiran kognitif yang penting, iaitu Pemikiran Kreatif dan Inovatif; Pemikiran Kritis dan Penaakulan; dan sebagainya. Tidak dapat dinafikan bahawa setiap murid perlu membina
kemahiran inkuiri dan pelbagai kemahiran berfikir untuk mempertingkatkan kualiti diri mereka dalam
mendepani arus cabaran di era globalisasi. Sebagai contoh, kemahiran berfikir aras tinggi (KBAT) dan
kemampuan untuk melakukan inovasi didapati amat perlu dalam dunia teknologi yang berkembang pesat ini. Persoalannya, bagaimanakah guru boleh memainkan peranan mereka di peringkat sekolah ? Perlukah mereka mengaplikasikan pelbagai kemahiran berfikir dalam pengajaran dan pembelajaran dalam kelas ? Sekiranya perlu, bagaimanakah caranya ? Rosnani (2013) berpendapat hanya guru yang kritis sahaja yang boleh melahirkan murid yang kritis di sekolah kerana komponen kemahiran berfikir
telah wujud dan bergantung kepada tafsiran guru serta bagaimana guru dapat merancang dan melaksanakan kemahiran tersebut (Pushpalatha, 2006). Hasil kajian diharap dapat menyumbang dalam pembinaan formula Pemikiran Pintar (Smart Thinking) bagi menjana aspek teras dalam berfikir dan seterusnya membantu ke arah membangunkan Budaya Pintar (Smart Culture) melalui pembangunan Tabiat Pintar (Smart Habits) bagi merealisasikan aspirasi kerajaan untuk membina modal insan yang mempunyai minda kelas pertama
Perkembangan Pendidikan Islam di Nusantara: Malaysia dan Indonesia
No full textPenjajahan Barat telah banyak mempengaruhi pendidikan Islam di kebanyakan
negara Islam di dunia. Modenisasi dan sekularisme adalah dua nilai barat yang membawa
perubahan kepada model asas, konsep, dan prinsip pendidikan Islam. Makalah ini bertujuan
untuk meneroka perkembangan pendidikan Islam dalam menghadapi kedua-dua nilai tersebut,
bermula dari kemunculan Islam sehingga masa kini di Nusantara, dengan berfokus hanya
kepada Malaysia dan Indonesia. Kajian ini mendapati perkembangan pendidikan bagi umat
Islam di Malaysia dan Indonesia telah menunjukkan perubahan yang progesif serta penerapan
nilai-nilai modenisasi dan sekularisme dalam sistem pendidikan sehingga terwujudnya
dualisme. Walau bagaimanapun, kedua-dua aliran pendidikan (agama dan sekular) masih kekal
terpisah di kebanyakan negara Islam sehingga kini. Justeru, perlunya kepada perancangan dan
perlaksanaan kurikulum bersepadu yang bersifat Islamik yang sebenar. Usaha penyepaduan
kurikulum dalam sistem pendidikan Islam bukan tugas yang mudah kerana memerlukan
komitmen dan usahasama daripada pelbagai pihak
Penerapan Model Pembelajaran Numbered Head Together di Sekolah Rendah Wilayah Aceh Barat
No full textPembelajaran merupakan satu unsur penting untuk mencapai keberhasilan dalam pengajaran.
Proses transformasi ilmu pengetahuan serta nilai berlaku dalam proses pembelajaran itulah terjadi.
Di samping itu juga, interaksi antara guru dengan murid turut berlaku dalam proses tersebut bagi
pihak guru mengenali secara langsung karakteristik serta potensi yang dimiliki murid. Kekurangan
hasil pembelajaran murid terhadap bahan pengajaran adalah disebabkan oleh pelbagai faktor
seperti kekurangang aktiviti murid semasa pengajaran. Ini kerana murid tidak bermotivasi untuk
melalui proses pembelajaran dan guru mengajar dengan menggunakan kaedah yang dapat membuat
murid merasakan ketepuan. Penerapan model pembelajaran koperatif Numbered Head Together
(NHT) dipercayai dapat meningkatkan pengetahuan dan hasil belajar murid. Kajian ini bertujuan
untuk mengukur peningkatan tahap pencapaian hasil belajar murid terhadap subjek Sains dengan
menggunakan model tersebut, di samping mencadangkan model yang boleh di terapkan secara
berkesan terhadap pencapaian murid di sekolah rendah. Kajian ini menggunakan pendekatan kaedah
kuantitatif dengan pensampelan seramai 143 murid dari empat sekolah rendah di wilayah Aceh
Barat. Data dianalisis dengan menggunakan SPSS V.20 untuk mencapai objektif kajian. Dapatan
kajian ini menunjukkan terdapat peningkatan dalam hasil belajar murid, yang dapat dilihat daripada
hasil skor yang membuktikan nilai min pada ujian pre-test yang jauh berbeza dengan min pada ujian
post-test. Nilai min pada ujian post-test ialah lebih tinggi daripada nilai min pada ujian pre-test.
Hasil analisis tindak balas murid kepada model pembelajaran koperatif jenis NHT dapat
menghujahkan bahawa murid memberi respons yang amat baik dengan hasil analisis tindak balas
murid pada setiap item
Study on setting time and compressive strength performance of ordinary portland cement (OPC) paste containing sodium chloride
Full text linkThe presence of impurities in concrete system can possess a damaging effect to
the structural integrity of concrete material. Alkali silica reaction, scaling, and corrosion
are among the deleterious effect caused by the ingression of internal or external
substance to the concrete system. Sodium chloride or salt is one of the external agents
involved in the process; hence its excessive amount in concrete system is strictly
prohibited. Nevertheless, concrete containing
salt
water is generally known for the
higher early-strength, yet lower ultimate strength than plain concrete. Meanwhile, study
on the detail mechanism in early age properties are scarcely available, particularly at
low salt concentration. Therefore this research was conducted to provide better
understanding in the effect of salt water to the hardening mechanism of Portland cement
paste and to obtain the optimum salt inclusion that contributes to the enhancement of
concrete properties. Analysis on the performance of this reagent was conducted via
setting time, compressive strength, and porosity test. Based on the setting time analysis,
the inclusion of sodium chloride can extend the initial setting time of cement paste
longer than control specimen. Obstruction on the formation of calcium silicate hydrate
gel by sodium and chloride ion was one of the possible causes to this phenomenon.
Acceleration on the compressive strength development by sodium chloride was also
detected. It appears that sodium chloride was able to de-flocculate the coagulated
cement particles and reduced the viscosities of cement slurries; hence resulted in faster
early hydration process. Based on the results of this research, it can be concluded that
sodium chloride inclusion is beneficial to the workability and compressive strength
performance of cement paste binder at certain concentration. Improvement of
compressive strength was achieved via faster dissolution and hydration of cement
particle due to dispersant characteristic presented by sodium chloride
PENTAKSIRAN PEMBELAJARAN HOLISTIK DAN IMPLIKASI KEPADA SISTEM PENDIDIKAN NEGARA
No full textKertas kerja ini bertujuan untuk membina satu bentuk pentaksiran yang holistik untuk dilaksanakan dalam sistem pendidikan di Malaysia. Kajian ini amat signifikan kerana
pentaksiran merupakan jantung kepada pengalaman pelajar dan mencerminkan kurikulum yang sebenar. Pada hakikatnya, masa dan tumpuan pelajar lebih diarahkan kepada pentaksiran berbanding aktiviti kurikulum yang lain, oleh itu, secara sedar atau tidak, hal ini banyak mempengaruhi tingkah laku dan gaya pembelajaran mereka. Kajian telah mendapati bahawa wujud masalah dalam amalan pentaksiran di sekolah yang lebih cenderung kepada orientasi
peperiksaan dan kesannya telah membentuk minda pelajar yang jumud. Permasalahan ini amat perlu dikaji untuk mencari jalan penyelesaian yang praktikal memandangkan pelajar merupakan modal insan yang akan membentuk generasi baharu. Persoalan yang harus diambil serius ialah; apakah bentuk pentaksiran yang sesuai untuk dilaksanakan dalam pendidikan di Malaysia? Bentuk pentaksiran tersebut haruslah dapat memenuhi hasrat kerajaan untuk melahirkan modal insan holistik dan berkualiti supaya berjaya menghadapi cabaran era globalisasi. Meskipun pada peringkat sekolah di Malaysia, perlaksanaan Sistem Pentaksiran Pendidikan Kebangsaan (SPPK) telah menekankan kepada pendekatan pentaksiran untuk pembelajaran (assessment for learning)
dan pentaksiran kepada pembelajaran (assessment to learning). Masalah akan timbul kerana kedua-dua pendekatan tersebut hanya berpusatkan guru sebagai pentaksir. Pengkaji mencadangkan supaya pendekatan pentaksiran sebagai pembelajaran (assessment as learning) juga diambil kira kerana pendekatan ini memberi fokus terhadap peranan pelajar sebagai pentaksir. Justeru, kajian ini membina satu bentuk pentaksiran yang lebih holistik dan menekankan kepada ketiga-tiga pendekatan pentaksiran dalam pembelajaran iaitu untuk, sebagai
dan kepada (for, as, of). yang bertujuan untuk membantu untuk mempertingkatan kualiti pelajar dari pelbagai aspek termasuk pembelajaran dan potensi diri mereka Kajian ini bersifat kualitatif dan menggunakan kaedah deskiptif dan analitikal. Kajian ini akan memberi implikasi kepada
sistem pendidikan negara dalam usaha untuk menjana modal insan berkualiti
Implementation of Integrated educational system in Malaysia Higher Education Institutions, IIUM and USIM
No full textThe study aims to analize the integrated educational system in Malaysian Higher Education Institutions The methods are involves the curriculum criticism, historical and philosophical analysis. It is a fact that compared to inslltut1ons which provide Islamic oriented education in different field, the Muslim world has increased number of secular schools, colleges and universities. Certain universities provide certificates in Islamic studies or education, in separate, standalone departments. The existence of these contradicting systems of education has caused educational dualism, coexistence of 'secular' and religious sciences, which poses dilemma facing the Ummah today. Consequently, the integration of both Naqli and Aqli into an integrated curriculum Is viewed as the best solution to solve this problem. Naqli knowledge is a knowledge that is sourced on the Quran and Sunnah of the Prophet Muhammad while Aqli knowledge is sourced from the rationale and findings of human thought sin relationship with the progress of human civilization. To analysize the implementation of this integrated knowledge, it will briefly explore the Islamic heritage of higher education and the contemporary models of so called
integration made possible, as in the case of International Islamic University Malaysia (IIUM) and Islamic Science University Malaysia (USIM). For IIUM and USIM there is a great diversity in their curricula, objectives, contents and their educational systems. Despite their glorious attempts to lslamise or integrate their curricula, there is always many rooms for improvement
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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