13474 research outputs found
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Role of sulphate on corrosion inhibition of aluminium alloy in acidic environment / Norshamira Mazlan
No full textAcid accelerates the corrosion process of aluminium. In this study, sulphate is used to
study the corrosion inhibition on 5052 aluminium alloy surfaces. Sodium sulphate is
added into different pH of acid solution. Concentrated sodium hydroxide was used to alter
the pH of concentrated hydrochloric acid to get the desired pH 2, pH 4 and pH 6. Distilled
water is used to prepare pH 7 to compare the behaviour of sulphate in acid and neutral
electrolytes. Potentiodynamic polarisation measurement was employed to evaluate the
electrochemical characteristics of the aluminium samples. While assessing the
performance of the inhibitors, the effect of inhibitor concentrations in the acidic and
neutral electrolytes are also to be studied. The corrosion rates of the aluminium samples
were reduced when sulphate inhibitor was added into the acidic electrolyte. It is found
that the corrosion density of aluminium samples was reduced with increasing inhibitor
concentration until 400 mg/L in all pH conditions and the maximum efficiency is
identified at pH 6 with 67.4% . From Tafel plots, sulphate acts as anodic-dominant
inhibitor in acidic environment. The corroded samples were analysed under optical
microscope for surface characterisation. The morphological images study on aluminium
alloy samples perceived that uniform corrosion happened on the aluminium surface with
slightly pitting on certain areas
Social cognitive framework for secure information sharing on Islamic NGO social media / Nurul’Adilah Nazri
No full textThe use of social media technologies such as Facebook, Twitter, Wikis, WhatsApp, and so forth is becoming a trend nowadays. Professionals often use social media in social work as an information and communication tool. Most profit organizations use this technology to help their business. Non-profit organizations are also known as non-governmental organizations (NGOs) also benefit in many aspects from using this technology. This research focused on Islamic NGOs which addressed education as one of their social missions. This research aims to achieve three main objectives; 1) to identify factors that influence secure information sharing practices of Islamic NGOs in spreading social mission using social media; 2) to develop social cognitive framework for secure information sharing by Islamic NGOs in spreading social mission using social media; and 3) to verify social cognitive framework for secure information sharing by Islamic NGO in spreading social mission using social media. A quantitative method was used in this research to find out the relationship between Personal/Cognitive, Behavior and Environmental determinants through Social Cognitive Theory. It started with data collection from 73 of NGO members to find out the usage of social media in the NGOs. The data were analyzed using structural equation modelling (Structural Equation Modelling (SEM)) technique using Partial Least Square (Partial Least Square (PLS)). The results show high reliability of predicted variables with reliability score of more than 0.80, displaying average variance extracted (Average Variance Extracted (AVE)) exceeding 0.5, define adequate convergent validity of all the predicted variables developed in the conceptual framework. It was found that from hypothesis 2, the behavioral determinant positively influences secure information sharing of Islamic NGOs through social media and from hypothesis 3, the environmental determinant positively influences secure information sharing of Islamic NGOs through social media. However, from hypothesis 1, it was found that personal/cognitive determinant does not positively influence secure information sharing of Islamic NGOs through social media. The social cognitive framework developed in this study shows the coefficient of determination (R2) is 0.584 which indicates the significance of predictive accuracy
Layered system architecture of remote robotic laboratory for real-time distant learning / Faisal Mahmud
No full textLaboratory experimental practice is an integral part of every day’s teaching and learning concerns in science and engineering courses. Under Industrial Revolution 3.0 schematic, the teaching of laboratory subjects has always been executed manually with the help of electrical instruments and data logging devices. Traditionally, a class full of students does not allow all participants to conduct laboratory exercises individually due to the minimal resources and time management. In this light, there is an urgent need to rejuvenate the current way of lab execution by injecting elements of Industrial Revolution 4.0 which centralizes internet tools coupled with the robotic system. Moreover, during an unprecedented time, such as the Covid-19 pandemic has enforced and proved a high demand to conduct laboratory experiments remotely by utilizing existing institutional online learning facilities. Therefore, working on laboratory exercises remotely via the server-based application may alleviate the difficulties in a traditional laboratory environment. In this research, a real-time online platform for performing lab exercises remotely has been proposed. This ‘Remote Robotic Laboratory’ would allow lab execution to be conducted remotely via an internet platform which promotes flexibility as well as brings more joy and excitement to the user. With this idea, the current project focuses on establishing a prototype of an online laboratory system that incorporates human interface software and hardware modules. The findings from our studies show that the proposed method was able to provide the students with a major increase in flexibility and performance. After the establishment of the system run time survey has been conducted with the help of students to evaluate the performance of the proposed facility. The investigation on the system response indicates good performance under different levels of internet bandwidth. The reliability of data recording was verified with the theoretical calculation which indicates a synchronized data transfer as low as 30ms interval. The survey on the user perception indicates more than 80% satisfaction over the concept
Pensijilan halal Malaysia: Isu dan cabaran premis makanan Korea di Malaysia /Al ‘Uyuna Mohd Amin
No full textThe Korean wave had a major impact on the entire world, and Malaysia was one of the countries that was affected. Korean influence can be found in a variety of industries, including food and beverage, cosmetics and personal care, electronics, and so on. However, the issue of applying for halal certification for Korean food premises due to the use of questionable ingredients is part of the challenges faced by Korean food premise entrepreneurs in Malaysia. Thus, this study discussed the implementation of Halal certification in Korean food premises in Malaysia as well as issues and challenges faced by premise entrepreneurs when obtaining halal certification. This study was conducted qualitatively where document analysis methods and interview sessions were implemented to meet the objectives of the study. Findings from the interviews found that five main issues in halal certification in Korean food premises have been identified, namely the use of alcohol containing ingredients from natural fermentation processes, the use of synthetic materials that can harm consumers, the small number of Korean Halal certification bodies recognized by JAKIM, the workload of Halal Executives who do not only focus on Halal as well as communication problems in the MYeHALAL system, In conclusion, most Korean food entrepreneurs want to achieve JAKIM Halal certification, but this requires a high level of commitment and cooperation from firm management to ensure that the Halal certification process is thoroughly followed
The role of kenaf and montmorillonite clay on the enhancement of the properties of polyhydroxybutyrate composites / Muhammad Rafiq Mohd Isa
No full textKenaf reinforced and montmorillonite (MMT) modified polyhydroxybutyrate (PHB) composites were prepared using a twin-screw extruder and injection moulding machine. The influence of reinforcement content and surface treatment on the composites' mechanical, rheological and thermal properties was investigated. The samples were moulded into a bar and dumb-bell shaped specimens and subjected to dry-as-moulded, indoor, outdoor and soil burial conditions for four months. The composites were characterised for thermal, rheological and mechanical properties. The results were supported by images obtained from microscopy techniques such as field emission scanning electron microscopes (FESEM) and transmission electron microscopes (TEM). Weibull analysis of single fibre tensile test results indicates fibre damage due to a high concentration of sodium hydroxide or longer soak time. Kenaf reinforced PHB exhibited up to 21% improvement in Young’s modulus. The presence of fibres in the polymer melt modified its flow behaviour from Newtonian (in pure PHB melt) to shear thinning behaviour. Fracture energy and critical strain energy release rate of the kenaf reinforced composite was increased with the addition of 20% kenaf fibres. FESEM image showed gaps between the PHB matrix and treated kenaf fibres, indicating that interfacial adhesion is still poor. However, the melt behaviour, such as the complex viscosity and storage modulus obtained through the rheological study of the treated kenaf PHB composites, shows improvement in interaction. Long term mechanical properties of treated kenaf composites also showed better performance. Energy dispersive X-ray mapping revealed that nanocomposites with clay content of 3 phr exhibited better dispersion than nanocomposites with higher clay content. The mechanical properties of the MMT-modified PHB, such as the tensile and flexural modulus, were enhanced compared to neat PHB. From the rheological study, PHB and PHB nanocomposites modified with untreated MMT exhibited Newtonian fluid behaviour in the tested frequency range. However, for nanocomposites modified with acid-treated MMT, shear-thinning behaviour was observed at higher clay content. The nanocomposites also exhibited higher complex viscosity compared to PHB. From transmission electron microscopy analysis, exfoliation of the MMT was observed for the treated MMT nanocomposites at all clay loading. MMT-modified PHB has lower melting temperature when compared to neat PHB. Furthermore, it was found that the addition of MMT influenced the crystallisation behaviour of PHB. The presence of acid-treated MMT also reduced the degree of crystallinity with increasing clay content. MMT modification of PHB was shown to reduce the rate of PHB biodegradation when buried in the soil
Geodesic deviation equation in symmetric teleparallel gravity / Beh Jing Theng
No full textThis dissertation surveys mathematical concepts of pseudo-Riemannian manifolds, reviews several gravity theories and describes the geodesic deviation equation i
Quadratic inference function with ridge estimator for myopic regret-regression: The short-term strategy in optimal dynamic treatment regimes / Nur Raihan Abdul Jalil
No full textA dynamic treatment regime (DTR) is a multi-stage decision rule based on treatment
history. The focus in this research is on the improvement of estimation in optimal dynamic
treatment regime (ODTR). This research is motivated by the regret-regression method
where it is a combination of the regret function with regression modeling. A short-term
strategy called the myopic regret-regression (MRr) is an alternative to regret-regression
where it estimates the mean response at each time-point. This strategy has the same
performance as regret-regression but MRr calculation is faster in estimation and more
practical in application. However, it has a limitation on correlated data. The quadratic
inference functions in myopic regret-regression (QIF-MRr) has overcome the limitation
of MRr by combining the myopic regret-regression with quadratic inference functions.
It is more robust and efficient regardless of any type of working correlation structure.
However, singularity problem happen when estimating the parameters using QIF-MRr and
more complex in computations. Hence, the ridge quadratic inference functions for myopic
regret-regression (rQIF-MRr) is proposed where a ridge estimator is used to overcome the
computational problem and shorten the calculation time. Comparison between methods
was performed to check the efficiency and consistency in estimation using simulation with
different sample sizes
Molten fluoride salt-assisted synthesis of mxenes as potential material for nonlinear photonic devices and applications / Aizuddin Ahmad Kamely
No full textGroup 4–6 transition metal carbides and nitrides were explored in the twentieth century as promising materials. Their catalytic behavior were founded in the 1970s that led to the exploration towards energy storage applications. Henceforth, a number of nanostructure designs have been introduced, taking tiny steps to enhance the surface area and performance of transition metal carbides and nitrides. The breakthrough in the area took place in 2011 by the discovery of the first two-dimensional (2D) titanium carbide (Ti3C2Tx) that give birth to a family of 2D transition metal carbides and nitrides, named MXenes (pronounced “maxines”). MXenes have become a large and quickly growing family of 2D materials ever since. In comparison to the other 2D materials, MXenes is relatively new and has not been extensively studied, especially in photonics field. The aim of this study is to synthesize MXenes from precursor MAX phases in non-standard method due to the harmful properties of hydrofluoric acid (HF) used in the standard method. A mixture of molten fluoride salt and acid (HF-forming etchant) is utilized instead, with different concentration, temperature, time, and procedures depending on the type of MXenes. Three different MXenes are being investigated in this work, titanium carbide (Ti2C), vanadium carbide (V2C), and niobium carbide (Nb2C), all three compounds with similar chemical ratio. Preparations and characterizations of the MXenes are described in detail such as lateral size, elemental composition, linear absorption, and nonlinear absorption. Besides synthesis, the MXenes are integrated in fiber laser systems, comprising of pulsed fiber laser, four wave mixing, and all-optical modulation to explore the performance. The optical response of the three MXenes are recorded with typical measurement according to each configuration. The studies commenced and the findings obtained in this study can contribute to the advancement of MXenes in photonics application
Rawatan pemulihan dadah di Pondok Baitul Taubah Pasir Puteh Kelantan dan Klinik Cure & Care Sungai Besi Kuala Lumpur: Analisis perbandingan menurut perspektif hadith / Sulawati Suhaimi
No full textDadah adalah musuh negara, isu penagihan dadah dalam kalangan remaja khususnya semakin menular dan semakin meningkat, pelbagai cara dan program telah dilaksanakan oleh kerajaan terutama Agensi Anti Dadah Kebangsaan (AADK), pusat-pusat rawatan persendirian dan pondok-pondok yang ditubuhkan bagi menyelesaikan isu penagihan dadah ini. Namun, penyelesaian sepenuhnya terhadap masalah ini masih belum tamat dan sehingga kini masih berlaku yang turut menyebabkan peningkatan jenayah. Kajian ini bertujuan untuk mengenalpasti pendekatan dan kaedah rawatan pemulihan dadah di Malaysia melalui kajian terhadap pendekatan dan kaedah rawatan pemulihan penagihan dadah di Pondok Baitul Taubah Pasir Puteh dan di Klinik Cure & Care Sungai Besi Kuala Lumpur. Keseluruhan aspek pendekatan dan kaedah rawatan pemulihan penagihan dadah tersebut kemudiannya dinilai dari perspektif hadith. Kajian ini adalah bersifat kajian kualitatif iaitu melalui kajian kes yang menggunakan kaedah temu bual dengan penagih dadah dan kakitangan yang terlibat dalam melaksanakan rawatan dan pemulihan, di samping kaedah pemerhatian terhadap proses rawatan yang dijalankan di pusat-pusat tersebut. Keseluruhan data dianalisis berdasarkan analisis induktif, deduktif dan komparatif. Hasil kajian mendapati bahawa pemulihan penagihan dadah dalam kalangan penagih sangat memerlukan elemen Islam kerana ia dapat memberi kesan yang mendalam dalam proses pemulihan diri penagih. Hasil kajian menunjukkan faktor kerohanian adalah aspek utama dalam membantu memulihkan bekas penagih dadah iaitu dengan melakukan amalan zikir dan solat malam yang dapat memberi ketenangan jiwa penagih di samping amalan mandi malam yang turut membantu dari sudut fizikal ketagihan. Dapatan juga menunjukkan bahawa terdapat beberapa hadith yang bertepatan dan boleh dijadikan sebagai panduan dalam rawatan pemulihan penagih dadah ini. Pemahaman terhadap hadith-hadith berkenaan dapat dijadikan ikutan yang sewajarnya dalam menghadapi isu pemulihan ini. Justeru, diharapkan pihak berwajib dan semua pihak dapat terlibat dalam menekankan aspek kerohanian Islam dalam membantu pemulihan para penagih yang ada bagi membendung penularan penagihan dadah ini lebih parah
Da’wah semantics of the explicit command and prohibition theme in the Qur’anic stories and their impact on the da’wah: A study applied to the imams of the State of Kuwait / Mohamed Abdelnaser Ahmed Elfakharani
No full textThe study of the methods of command and prohibition in the Qur’anic stories is considered one of the important studies in the art of Da’wah. The study aims to identify their semantics’ implications on Da’wah for the purpose of employing them in addressing the deviations and wrong Da’wah practices that resulted from rapid developments in various aspects of life. Flexible Da’wah rules, to be derived from the semantics of the Qur’anic discourse styles, primarily from the explicit order and prohibition methods, due to their numerous occurrences and the diversity of their implications, could accommodate those life developments and guide the Da’wah practices. The study revealed a set of benefits, including: defining the mission of the preacher, listing the elements of its success, indicating the preacher’s typical relationship and elements of the successful preaching discourse with the invitees, describing the characteristics of a successful preacher, identifying the rights and duties of the invitee, and stressing the objectives of da’wah and consolidating them in the hearts of the invitees. The study attempted to apply the inferred Da'wah rules to some contemporary developments and realities. A field study was conducted on a number of imams of mosques (being preachers) to measure the understanding level of the semantics of the explicit style of command and prohibition in the Qur’anic stories, and the impact of identifying them in the field of Da’wah. The researcher adopted the inductive, analytical, and descriptive, qualitative and quantitative approaches, and used the interview and questionnaire as tools to measure the extent of clear understanding of these semantics and their impact on the work of Da’wah. A questionnaire was distributed to one hundred imams at the Ministry of Awqaf (Endowments) in the State of Kuwait, and interviews were held with a group of specialists in order to test the hypotheses of the study in the field. The findings showed that inferring the semantics’ Da’wah implications from the methods of command and prohibition in the Qur’anic stories contributed to the preachers’ better comprehension of the proper Islamic Da’wah methodology, whose principles are characterized by the combination of stability, flexibility, originality and contemporariness. The study recommends devoting the efforts of research in Da’wah to studying everything related to the semantics of discourse styles in the realm of the Qur’anic stories in order to find out the Da’wah guidelines which constitute a strong methodological bases because they derive their strengths from their powerful source, the Holy Quran