This study investigates the effect of temperature on the damping behaviour, stiffness, and natural frequency of hybrid conductive ink (HCI) printed on a copper (Cu) substrate. The HCI comprises graphene nanoplatelets (GNPs), silver flakes (SF), and silver acetate (SA). The objective is to evaluate the HCI’s electrical conductivity and mechanical properties under varying thermal conditions. The HCI paste was formulated with a specified ratio of organic solvents, terpineol, and 1-butanol and cured in an oven at 260°C for 3 hours. The baseline droplet ratio was set at 1:1, and three Cu samples with varied HCl compositions were printed using a 60 µm mesh stencil process. The terpineol concentrations were changed while the 1-butanol droplet remained constant. The samples were then tested for electrical conductivity at room temperature using a two-point probe, in accordance with IEEE Std 118-1978, followed by mechanical behaviour testing using an ASTM E756-05 impact test. Furthermore, the samples were exposed to a range of temperature tests to evaluate mechanical and electrical conductivity under thermal stress. The results showed that the baseline composition exhibited minimal resistance and resistivity across the temperature range, with an average resistance of ? 0.2 ? and a resistivity of ? 0.8 ? · mm, respectively. The baseline composition also exhibited reduced stiffness and damping, with natural frequencies of 10.90, 1.40 kN/m, and 37.51 Hz across the samples. Therefore, the baseline composition exhibits relatively good electrical and mechanical properties for applications in flexible electronics. ABSTRAK: Kajian ini meneliti kesan suhu terhadap sifat redaman, kekakuan, dan frekuensi semula jadi bagi dakwat konduktif hibrid (HCI) yang dicetak pada substrat kuprum (Cu). HCI ini terdiri daripada graphene platelet nano (GNP), serpihan perak (SF), dan perak asetat (SA). Objektif kajian ini adalah bagi menilai kekonduksian elektrik dan sifat mekanikal HCI di bawah keadaan haba berbeza. Pes HCI dibangunkan dengan nisbah tertentu pelarut organik, terpineol dan 1-butanol, dan dikeringkan dalam ketuhar pada suhu 260?C selama tiga jam. Nisbah titisan asas ditetapkan pada 1:1, dan tiga sampel Cu dengan komposisi HCI berbeza telah dicetak menggunakan proses stensil jaring 60 µm. Kepekatan terpinol diubah manakala titisan 1-butanol dikekalkan pada kadar yang sama. Sampel-sampel tersebut kemudiannya diuji bagi kekonduksian elektrik pada suhu bilik menggunakan probe Dua-Titik mengikut kod ujian piawaian IEEE Std 118-1978 dan diteruskan dengan ujian sifat mekanikal menggunakan ujian impak ASTM E756-05. Tambahan, sampel telah terdedah kepada pelbagai ujian suhu bagi menilai kekonduksian mekanikal dan elektrik di bawah tekanan haba. Dapatan kajian menunjukkan bahawa komposisi asas menunjukkan rintangan dan kerintangan minimum sepanjang julat suhu, dengan purata rintangan ? 0.2 ? dan kerintangan ? 0.8 ?/mm. Komposisi asas juga menunjukkan sifat mekanikal dengan kekakuan berkurangan, tingkah laku redaman, dan frekuensi semula jadi masing-masing sebanyak 10.90, 1.40 kN/m, dan 37.51 Hz merentasi sampel. Oleh itu, komposisi asas menunjukkan sifat elektrik dan mekanikal yang agak baik bagi aplikasi elektronik fleksibel.

The delivery of critical communication, navigation, and earth observation services relies on the reliability of satellite subsystems. However, satellites can be affected by radiation and temperature extremes. Anomalies can cause the system to fail and stop working. This research aims to fix the lack of a high-performance reliability model compared to previous work by integrating trade-space exploration (TSE) techniques and an exponential reliability mathematical model. Data from the Seradata database was analyzed using MATLAB to check for issues with antennas, transponders, amplifiers, and batteries as the prominent components of satellite anomalies. Studies were carried out by building parametric (Weibull, Exponential, and Poisson) and non-parametric (Kaplan-Meier and Monte Carlo Simulation) models, and all were assessed. Results were measured using Root Mean Square Error (RMSE), revealing that the Exponential model performed most accurately compared to other mathematical models. After that, the TSE framework was applied to examine the Design Dependent Parameters (DDPs): reliability, design life, and system performance. The results conclude that the newly developed exponential-based reliability TSE model shows a promising outcome, with RMSE values of 34.2, 10.2, 19.6, and 19.9 compared to Nadirah’s model and Shazana’s model, which have RMSE values of 16.1, 49.7, 28.2, and 27.6 for antenna, transponder, amplifier, and battery, respectively. ABSTRAK: Penghantaran Penghantaran perkhidmatan adalah penting dalam komunikasi, navigasi, dan pemerhatian bumi pada kebolehcapaian subsistem satelit. Walau bagaimanapun, satelit boleh terjejas oleh radiasi dan perubahan suhu ekstrem. Anomali boleh menyebabkan sistem gagal dan berhenti berfungsi. Penyelidikan ini bertujuan bagi memperbaiki kekurangan model kebolehcapaian berprestasi tinggi daripada kerja terdahulu dengan mengintegrasi teknik penerokaan ruang dagangan (TSE) dan model matematik kebolehcapaian Eksponen. Data daripada pangkalan data Seradata dianalisa menggunakan MATLAB bagi memeriksa isu antena, transponder, penguat, dan bateri sebagai komponen utama anomali satelit. Kajian dijalankan dengan membina model parametrik (Weibull, Eksponen, dan Poisson) dan non-parametrik (Kaplan-Meier dan Simulasi Monte Carlo). Dapatan kajian diukur menggunakan Ralat Kuadrat Purata Akar (RMSE), menunjukkan bahawa model Eksponen berfungsi paling tepat berbanding model matematik lain. Kemudian, rangka kerja TSE digunakan bagi mengkaji Parameter Bergantung Reka Bentuk (DDPs), yang merangkumi kebolehpercayaan, hayat reka bentuk, dan prestasi sistem. Dapatan kajian menunjukkan bahawa kebolehpercayaan model TSE berasaskan eksponensial yang baru dibangunkan menunjukkan hasil yang memberangsangkan di mana nilai RMSE adalah 34.2, 10.2, 19.6, dan 19.9 berbanding dengan model Nadirah dan model Shazana adalah 16.1, 49.7, 28.2, dan 27.6 untuk antena, transponder, penguat, dan bateri.

The rapid development of surveillance technology is readily apparent, particularly in monitoring vast and remote locations that present difficulties for human accessibility. Within the realm of contemporary surveillance methods, the utilization of Unmanned Aerial Vehicles (UAVs) has garnered a considerable amount of interest. The swift advancements in science and technology have led to the progressive incorporation of Artificial Intelligence (AI) technologies, particularly in tasks such as monitoring and reconnaissance. The results of this research contribute to the creation of a prototype for a UAV capable of conducting autonomous monitoring missions and integrating artificial intelligence technologies for real-time video processing. This study utilized an experimental methodology, and a Raspberry Pi was utilized for artificial intelligence processes integrated with the aircraft controller. During the decisive experiment, the unmanned aerial vehicle UAV could effectively travel to the designated area, reaching an accuracy of 78.6% in its AI processing. ABSTRAK: Perkembangan pesat teknologi pemantauan kini semakin ketara, terutamanya dalam pemantauan kawasan yang luas dan terpencil sukar diakses manusia. Dalam konteks kaedah pemantauan kontemporari, penggunaan Kenderaan Udara Tanpa Pemandu (UAV) telah menarik minat ramai. Kemajuan pesat sains dan teknologi telah menghasilkan gabungan teknologi Kecerdasan Buatan (AI) secara progresif, terutama dalam bidang pemantauan dan peninjauan. Penyelidikan ini memberi sumbangan kepada penciptaan prototaip UAV yang mampu menjalankan misi pemantauan sendiri, disamping gabungan teknologi kecerdasan buatan bagi memproses video masa nyata. Kajian ini menggunakan metodologi eksperimen dan Raspberry Pi yang disepadukan dengan pengawal pesawat bagi proses kecerdasan buatan. Semasa eksperimen penentuan, UAV berjaya bergerak dengan berkesan ke kawasan yang ditetapkan, mencapai ketepatan 78.6% dalam pemprosesan AI.

Metal pipes are the most integral part of transporting water, gas, and other petrochemical substances over long distances. Higher strength, durability (along with wear and corrosion resistance), and lower cost make these pipes suitable for extreme weather conditions and hostile environments. Over time, these pipes experience significant impacts that may lead to defects such as holes, cracks, bends, corrosion, and finally component failure and property losses. Therefore, early detection of the defects in pipes is crucial to prevent such failures. There are several methods to detect defects in metal pipes, including non-destructive testing (NDT). However, high costs and declining performance are existing concerns for those NDTs. A motor-induced vibration source is more robust and reliable than a conventional vibration sensor. Thus, the feasibility of using a motor as a vibration source for metal pipe crack detection is studied in this work. To achieve this, a DC motor is placed on one side of the metal pipe and used as the vibration source. These vibrations are collected by a piezoelectric polymer, specifically a Polyvinylidene fluoride (PVDF) sensor, on the other side of the pipe. This work considers three types of pipe conditions: healthy pipe, bent pipe, and cracked pipe. Additionally, two different sensor locations (180-degree rotation) and sensor patterns (bent and not bent) are studied. From the studies, we can see that there are significant differences in pressure responses for healthy pipe and cracked pipe conditions. The maximum pressure response for a cracked pipe is 783 a.u. (intensity) whereas it is just 262 a.u. for a healthy pipe. Thus, the difference is sufficient to set a threshold margin. We have set 300 a.u. as the threshold margin and applied it to an algorithm. The algorithm can successfully detect a healthy or cracked pipe. However, it is very tricky in the case of a bent pipe, as the pressure differences are less than 300 a.u. for three conditions and above for only one. Hence, it might provoke an incorrect decision when detecting a bent pipe. ABSTRAK: Paip logam adalah bahagian utama dalam mengangkut air, gas, dan bahan petrokimia lain dalam jarak jauh. Kekuatan dan ketahanan tinggi (bersama rintangan hakisan dan penggunaan), dan kos lebih rendah menjadikan paip logam sesuai bagi keadaan cuaca dan persekitaran melampau. Walau bagaimanapun, dari masa ke masa, paip logam mengalami kesan ketara seperti berlubang, retak, bengkok, hakisan dan akhirnya kegagalan komponen dan kehilangan harta benda. Oleh itu, pengesanan awal kecacatan pada paip adalah sangat penting bagi mengelakkan kegagalan tersebut. Terdapat kaedah tidak merosakkan (NDT) bagi mengesan kecacatan pada paip logam. Walau bagaimanapun, kos yang tinggi dan prestasi merosot adalah kebimbangan sedia ada pada NDT. Sumber getaran dari motor adalah lebih berdaya tahan dan lebih dipercayai berbanding pengesan getaran konvensional. Oleh itu, kebolehlaksanaan motor sebagai sumber getaran bagi mengesan paip logam yang retak dikaji dalam kajian ini. Bagi tujuan ini, motor DC diletakkan pada satu sisi paip logam dan digunakan sebagai sumber getaran. Getaran ini dikumpul oleh pengesan polimer piezoelektrik Poliviniliden Fluorida (PVDF) pada bahagian lain paip. Tiga jenis keadaan paip, iaitu paip sihat, paip bengkok dan paip retak dipertimbangkan dalam kajian ini. Tambahan, dua lokasi pengesan berbeza (pada putaran 180 darjah) dan corak pengesan (bengkok dan tidak bengkok) dikaji. Dapatan kajian menunjukkan terdapat perbezaan ketara dalam tindak balas tekanan bagi paip berkeadaan sihat dan retak. Malah, tindak balas tekanan maksimum bagi paip retak adalah 783 a.u. (intensiti) sedangkan hanya 262 a.u. bagi paip sihat. Oleh itu, perbezaan ini cukup bagi menetapkan margin ambang. Kajian ini telah menetapkan 300 a.u. sebagai margin ambang dan menggunakannya pada algoritma. Algoritma ini berjaya mengesan paip sihat atau retak. Walau bagaimanapun, adalah sangat rumit bagi mengesan paip bengkok kerana perbezaan tekanan adalah kurang daripada 300 a.u. bagi tiga syarat tersebut. Oleh itu, ia mungkin mencetuskan keputusan yang salah bagi mengesan paip bengkok.

A simple nanocomposite consisting of MIL-53(Al) and reduced graphene oxide (rGO), denoted as MIL-53(Al)/rGO, was synthesized as a photocatalyst driven by sunlight and UV light to study the decomposition of methylene orange and methylene blue in aqueous solution. The MIL-53(Al)/rGO ultrafine particles were produced by an in situ method using the solvothermal technique. The nanocomposite was made with two different amounts of rGO, 2.5% and 5% by weight. Various tests, including XRD, N2 adsorption-desorption isotherms, SEM, SEM-EDS, UV-Vis DRS (Diffuse Reflectance Spectroscopy), and FTIR, were performed on all photocatalyst variations to analyse their properties. Results from SEM and EDS showed the creation of small MIL-53(Al) particles measuring 10-20 ?m and rGO spread evenly on the MIL-53(Al) surface, particularly in the 2.5% rGO sample. The photocatalytic effectiveness of the MIL-53(Al)/rGO nanocomposites was tested for degrading organic dyes (MO and MB) in water under both sunlight and UV light for 60- and 120-minute durations. The 2.5% rGO photocatalyst showed the highest performance, removing over 96% and 98% of the dyes after one hour of sunlight exposure for MB and MO, respectively. This demonstrates that the combined effect of MIL-53(Al) and rGO composite can be seen as an effective photocatalyst for breaking down reactive dyes, such as MO and MB, in water treatment applications. ABSTRAK: Kajian ini adalah berkaitan nanokomposit sederhana daripada MIL-53(Al) dan grafit oksida yang tereduksi (rGO), atau MIL-53(Al)/rGO, berjaya disintesis sebagai fotopemangkin oleh cahaya matahari dan cahaya UV bagi mengkaji penguraian metil jingga (MO) dan metilena biru (MB) dalam larutan akueus. Zarah ultrahalus MIL-53(Al)/rGO dihasilkan melalui kaedah in situ menggunakan teknik solvotermal. Nanokomposit dibuat dengan dua jumlah rGO berat berbeza, 2.5 wt% dan 5 wt%. Pelbagai ujian termasuk XRD, N2 penyerapan-nyahserapan isoterma (BET), SEM, SEM-EDS, UV-Vis DRS, dan FTIR telah dilakukan pada semua variasi fotopemangkin bagi mengkaji sifatnya. Dapatan kajian dari SEM dan EDS menunjukkan penciptaan zarah kecil MIL-53(Al) berukuran 10-20 ?m dan rGO tersebar secara rata pada permukaan MIL-53(Al), terutamanya dalam sampel rGO 2.5%. Keberkesanan fotopemangkin nanokomposit MIL-53(Al)/rGO telah diuji bagi mengurai pewarna organik dalam air, di bawah kedua-dua cahaya matahari dan cahaya UV selama tempoh 60 dan 120 minit. Fotopemangkin rGO 2.5% menunjukkan prestasi tertinggi, dengan penyingkiran lebih dari 96% MB dan 98% MO, selepas pendedahan cahaya matahari selama satu jam. Ini menunjukkan, kesan gabungan komposit MIL-53(Al) dan rGO, boleh dilihat sebagai fotopemangkin yang berkesan bagi memecahkan pewarna reaktif, seperti MO dan MB, dalam aplikasi rawatan air.

The IIUM Engineering Journal Vol. 26 No. 2 continues its mission of advancing scholarly excellence by featuring 22 high-quality papers that span a wide spectrum of engineering disciplines. This issue brings together cutting-edge research showcasing the dynamic and multidisciplinary nature of engineering in addressing real-world problems.Researchers explore sustainable and biologically driven innovations in the realm of Chemical and Biotechnology Engineering. Notably, identifying Rhizopus sp. fungi as an alternative lactic acid source and the ozonation of vegetable oils underscore efforts toward environmentally friendly biochemical processes. Civil and Environmental Engineering contributions highlight using natural materials for infrastructure, focusing on the feasibility of treated natural bitumen as a replacement for petroleum-based asphalt—an approach aligned with sustainable construction practices.The most significant representation comes from Electrical, Computer, and Communications Engineering, where numerous works delve into AI, signal processing, secure communications, and sensor networks. From deep learning-based anomaly detection and vision transformer analysis for driver fatigue, to latency evaluations of LEO and GEO networks under tropical conditions, these studies reflect the growing importance of digital intelligence and communication resilience. Contributions on flexible antenna designs, mobile applications for dyslexic learners, and modified grey relational analysis further showcase how electronics and AI are increasingly embedded in daily societal functions.In Materials and Manufacturing Engineering, the research on MSW-derived biochar for iron production and voltage-induced void formation in boiler tubes exemplifies innovation in resource utilization and reliability of industrial systems. Additionally, enhancing photocatalytic materials for water treatment presents promising strides in environmental engineering. Mechatronics and Automation Engineering advances are evident in developing regenerative braking systems for electric motorcycles and smart IoT-based solutions for e-bike sharing systems, both addressing urban mobility and energy efficiency. Finally, contributions in Engineering Mathematics and Applied Science provide theoretical underpinnings crucial for innovation, such as the study on the elliptic drum of vertical spindle cotton pickers, demonstrating the importance of mathematical modeling in optimizing mechanical design.This issue affirms the journal’s commitment to featuring impactful, interdisciplinary research that bridges theory and application. The editorial team extends sincere appreciation to all contributing authors, dedicated reviewers, and section editors whose efforts ensure the continued quality and relevance of the IIUM Engineering Journal.We hope this collection will inspire further research, inform policy and industrial practices, and foster collaborations across academia and industry to pursue sustainable and inclusive technological development..We extend our gratitude to the authors, reviewers, and editorial board for their unwavering commitment to excellence. Your contributions ensure this journal thrives as a beacon of scholarly inquiry and practical impact. Let us embrace these breakthroughs as stepping stones to a brighter, more sustainable future. Prof. Ir. Ts. Dr. Teddy Surya GunawanExecutive EditorIIUM Engineering Journal ISSN: 1511-788X E-ISSN: 2289-7860 Published by:IIUM Press,International Islamic University MalaysiaJalan Gombak, 53100 Kuala Lumpur, MalaysiaPhone (+603) 6421-5014, Fax: (+603) 6421-6298

The construction of toll roads in Indonesia has massively increased the need for concrete. Therefore, concrete manufacturing companies must select new raw material suppliers for concrete. This selection is based on several criteria, including qualitative and quantitative criteria. This study proposes a new methodology for supplier selection. The model captures decision-makers' dynamics in ranking suppliers by integrating quantitative and qualitative criteria. The first stage in the proposed model is determining the criteria using the Fuzzy Delphi Method (FDM). The second stage is weighting the criteria using the Fuzzy Step-wise Assessment Ratio (F-SWARA) II and the Method Based on Removal Effects of Criteria (MEREC). The last stage is supplier assessment using Fuzzy Measurement of Alternatives and Ranking According to Compromise Solution (F-MARCOS). One of Indonesia's largest concrete manufacturing companies was used to validate the proposed model. The results showed that the proposed model is valid and more effective than some previous methods. The company in the case study experienced a 5% reduction in production costs in the later stages of the toll project, following several months of implementation, indicating the effectiveness of the proposed methodology. ABSTRAK: Pembinaan jalan tol di Indonesia telah meningkatkan keperluan konkrit secara besar-besaran. Oleh itu, syarikat pembuatan konkrit mesti memilih pembekal bahan mentah baru konkrit. Pemilihan ini berdasarkan beberapa kriteria, termasuk kriteria kualitatif dan kuantitatif. Kajian ini mencadangkan metodologi baru untuk pemilihan pembekal. Model ini menfokuskan pembuat keputusan dinamik dalam kedudukan pembekal dengan menyepadu kedua-dua kriteria kuantitatif dan kualitatif. Peringkat pertama dalam model yang dicadangkan ini adalah menentukan kriteria menggunakan Kaedah Rawak Delphi (FDM). Peringkat kedua adalah menimbang kriteria menggunakan Nisbah Pentaksiran Rawak Langkah-Bijak (F-SWARA) II dan kaedah berdasarkan Kriteria Kesan Pengasingan (MEREC). Peringkat terakhir merupakan penilaian pembekal menggunakan Solusi Kompromi berdasarkan Pengukuran Rawak Alternatif dan Kedudukan (F-MARCOS). Salah satu syarikat pembuatan konkrit terbesar di Indonesia telah digunakan bagi mengesahkan model yang dicadangkan. Dapatan kajian menunjukkan bahawa model yang dicadangkan ini adalah sah dan lebih berkesan berbanding beberapa kaedah sebelumnya. Syarikat dalam kes kajian mengalami pengurangan 5% dalam kos pengeluaran pada peringkat akhir projek tol, iaitu selepas beberapa bulan pelaksanaan, menunjukkan keberkesanan metodologi yang dicadangkan.

Detection of anomalies within video streams continues to be challenging, mostly due to the complexities involved in distinguishing abnormal activities from normal ones. This study aimed to enhance anomaly detection performance by evaluating different deep learning models and optimizers. Utilizing the Keras framework and Python on a Kaggle notebook, the experiment explored the effectiveness of DenseNet121, VGG19, ResNet50, and InceptionV3 models in conjunction with Adam, SGD, RMSprop, and Adagrad optimizers. A UCF Crimes dataset subset focused on Accuracy, F1 Score, and AUC evaluation metrics. The results establish that the InceptionV3 model paired with the Adam optimizer outperforms the other combinations, attaining AUC scores of 0.9918. In contrast to other state-of-the-art models such as DenseNet121 and ResNet50, InceptionV3 presents enhanced precision and adaptability in handling the variability found in video anomaly datasets. This study enhances security by providing insights into enhanced model-optimizer combinations, advancing video surveillance approaches, and providing support for developing robust anomaly detection systems. ABSTRAK: Pengesanan anomali dalam strim video terus mencabar, kebanyakan disebabkan oleh kerumitan yang terlibat dalam membezakan aktiviti tidak normal dari biasa. Kajian ini cuba meningkatkan prestasi pengesanan anomali dengan menilai model dan pengoptimum pembelajaran mendalam yang berbeza. Menggunakan rangka kerja Keras dan Python pada komputer riba Kaggle, eksperimen ini meneroka keberkesanan model DenseNet121, VGG19, ResNet50 dan InceptionV3 bersama pengoptimum Adam, SGD, RMSprop dan Adagrad. Subset data Jenayah UCF digunakan, memfokuskan pada ketepatan, Skor F1 dan metrik penilaian AUC. Dapatan kajian menunjukkan bahawa model InceptionV3 bersama pengoptimum Adam, mengatasi kombinasi lain, mencapai skor AUC 0.9918. Berbeza dengan model canggih lain seperti DenseNet121 dan ResNet50, InceptionV3 mempunyai ketepatan dan kebolehsuaian yang tinggi dalam mengendalikan kebolehubahan yang terdapat dalam set data anomali video. Kajian ini menyumbang kepada peningkatan keselamatan dengan memberi gabungan pengoptimum bersama model yang dipertingkatkan, memajukan pendekatan pengawasan video dan menyediakan sokongan bagi pembangunan sistem pengesanan anomali yang teguh.

As an alternative to conventional construction material such as normal concrete, waste paper sludge ash (WPSA) based geopolymer is seen as a promising and viable option in construction material selection due to its high amount of aluminum (Al) and silicon (Si) content. This research aims to determine the microstructure and mechanical characteristics of WPSA in geopolymers. The alkaline solution that contains 6 M of sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) was used to activate the geopolymer. The hardened 50 mm-sized mortars were prepared and underwent a heat-cured process for 1 day at various temperatures at 24 ?, 60 ?, and 90 ?, respectively. Then, the mortar cubes were placed in the laboratory until the testing days. A compression test was conducted to identify the strength development of the WPSA-based geopolymer mortar at 7, 14, and 28 days, respectively. Chemical composition was analyzed using X-ray fluorescence (XRF). Furthermore, Fourier-transformed infrared spectroscopy (FTIR) was conducted to ascertain the structural elucidation and scanning electron microscope (SEM) analysis was done to provide microstructural observations of the geopolymer. Based on the XRF analysis, the WPSA has the highest amount of calcium oxide (CaO) instead of aluminum oxide (Al2O3) and silicon dioxide (SiO2), and it reduces the performance of WPSA as a cement replacement material. The ratio of SiO2 and Al2O3 is recorded as 1.1:1. Therefore, it is suitable for bricks and ceramics production instead of concrete production. As for the curing process, the heat-cured method is evident in accelerating strength development in the WPSA-based geopolymer mortar compared to the ambient curing method due to the rapid polymerization process in the geopolymer system. It is proven that 60 ? is the optimum temperature for the curing process for geopolymer mortar. ABSTRAK: Sebagai salah satu alternatif kepada bahan binaan konvensional seperti konkrit biasa, geopolimer berasaskan abu enap cemar kertas (WPSA) adalah dilihat sebagai pilihan yang baik kerana bahan ini mempunyai kandungan aluminium (Al) and silika (Si) yang tinggi. Penyelidikan ini bertujuan untuk menentukan struktur mikro dan ciri mekanikal WPSA dalam geopolimer. Larutan alkali yang mengandungi 6 M natrium hidroksida (NaOH) dan natrium silikat (Na2SiO3) digunakan untuk mengaktifkan geopolimer. Mortar yang bersaiz 50 mm telah disediakn dan ia melalui proses pengawetan haba selama 1 hari pada suhu yang berza-beza, iaitu 24 ?, 60 ?, and 90 ?. Kemudian, kiub mortar tersebut diletakkan di dalam makmal sehingga hari ujian. Ujian mampatan dijalankan untuk mengenal pasti perkembangan kekuatan mortar geopolimer apabila mencapai 7, 14, dan 28 hari. Komposisi kimia dalam sampel telah dianalisa menggunakan pendarfluor sinar-X (XRF). Tambahan pula, Spektroskopi inframerah fourier transformasi (FTIR) untuk memastikan sifat bahan dan analisis pengimbasan mikroskop elektron (SEM) untuk menyediakan pemerhatian struktur mikro geopolimer. Berdasarkan data dari analisa XRF, WPSA mempunyai jumlah kalsium oksida (CaO) tertinggi berbanding aluminium oksida (Al2O3) dan silikon dioksida (SiO2), dan ia mengurangkan prestasi WPSA sebagai bahan gantian simen. Nisbah SiO2 dan Al2O3 direkodkan sebagai 1.1:1. Oleh itu, ia sesuai digunakan untuk pengeluaran batu bata dan seramik berbanding pengeluaran konkrit. Bagi proses pengawetan, kaedah pengawetan haba terbukti mempercepat perkembangan kekuatan geopolimer berasaskan WPSA berbanding pengawetan pada suhu ambien disebabkan berlakunya proses pempolimeran yang sangat pantas dalam sistem geopolimer tersebut. Telah terbukti bahawa suhu 60 ? adalah suhu optimum bagi proses pengawetan mortar geopolimer berasaskan WPSA ini.

Stiffness is one of the most critical characteristics of a building, which is considered for public safety against earthquake loads and refers to displacement resistance. Buildings must be built with proper strength and stiffness. This study uses pushover analysis to evaluate the parameters influencing the stiffness of the RC Dual system. The research used ASCE 7-10 and ACI 318-08 codes to design 24 two-dimensional buildings. Pushover analysis is conducted in the models using the ETABS software. Factors, including the number of stories, span length, thickness of the shear walls, and compressive strength, were considered while evaluating the stiffness and base shear of the designed buildings. The highest stiffness factor is (149.30) found in low-rise buildings with smaller span lengths, higher shear wall thickness, and higher compressive strength. In comparison, the lowest stiffness factor of (27.88) appeared in high-rise buildings with longer span lengths, lower shear wall thickness, and lower compressive strength. This study analyzed a dual system consisting of a moment-resisting frame and a shear wall. In further studies, other structural systems can be considered. By increasing the span length from 5.5m to 6.5m, the stiffness factor decreases by 8%. While by increasing shear wall thickness, the stiffness factor increased by 4.5%. Since every sample consists of two-dimensional dual systems, the influence of torsion is avoided. Future work should take torsional impacts into account since they have the potential to impact the design. ABSTRAK: Untuk menyediakan keselamatan umum terhadap daya gempa, salah satu ciri bangunan yang paling penting ialah kekakuan, yang menerangkan tentangan terhadap anjakan. Bangunan mesti dibina dengan kekuatan dan kekakuan yang betul. Kajian ini menggunakan analisis pushover untuk menilai parameter yang mempengaruhi kekukuhan sistem RC Dual. Penyelidikan menggunakan kod ASCE 7-10 dan ACI 318-08 untuk mereka bentuk 24 bangunan dua dimensi. Analisis pushover dijalankan dalam model menggunakan perisian ETABS. Beberapa faktor, termasuk bilangan tingkat, panjang rentang, ketebalan dinding ricih, dan kekuatan mampatan, diambil kira semasa menilai kekukuhan dan ricih asas bangunan yang direka bentuk. Faktor kekukuhan tertinggi yang diukur dengan membahagikan ricih asas kepada anjakan (149.30) muncul di bangunan bertingkat rendah dengan panjang rentang yang lebih kecil, ketebalan dinding ricih yang lebih tinggi, dan kekuatan mampatan yang lebih tinggi. Manakala faktor kekakuan terendah (27.88) terdapat pada bangunan bertingkat tinggi dengan panjang rentang yang lebih panjang, ketebalan dinding ricih yang lebih rendah, dan kekuatan mampatan yang lebih rendah. Hanya kerangka tahan momen dengan dinding ricih yang dipanggil model (sistem dwi) telah dianalisis dalam kajian ini; sistem struktur lain boleh dipertimbangkan dalam kajian lanjut. Dengan meningkatkan panjang rentang daripada 5.5m kepada 6.5m, faktor kekakuan berkurangan sebanyak 8%. Manakala dengan meningkatkan ketebalan dinding ricih, faktor kekakuan meningkat sebanyak 4.5%. Memandangkan setiap sampel terdiri daripada sistem dwi dua dimensi, pengaruh kilasan dielakkan, kerja masa hadapan harus mengambil kira kesan kilasan kerana ia berpotensi memberi kesan kepada reka bentuk.