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Evaluation of polypyrrole-polyethylenimine (PPY-PEI) conducting polymers as adsorbents for the removal of methyl orange and crystal violet from polluted solutions / Norhabibah Mohamad
No full textVarious conducting polymers have emerged as a new adsorbent for the removal of dyes from an aqueous environment. This research study focused on suitable polymeric adsorbents to remove dyes from aqueous solution at a very low cost, ease of preparation, and higher removal efficiency. Novel conducting polymer-based adsorbents, polypyrrole (PPy) and polypyrrole-polyethylenimine (PPy-PEI) have successfully been prepared as new adsorbents and utilized in the adsorption of dyes such as methyl orange (MO) and crystal violet (CV) dyes from aqueous environment. The adsorption characteristics of the prepared polymer-based adsorbents were characterized by the Brunauer-Emmet-Teller (BET) surface analyzer in order to measure the surface area measurements, Fourier transform infrared (FTIR) to identify the functional groups of the prepared adsorbents, X-ray diffraction pattern (XRD) to investigate the crystalline structure and field emission scanning electron microscopy (FESEM) to study the surface morphology of the adsorbents. The highest BET surface area of the PPy-PEI composite (1:1) was found to be 11.85 m2/g, which is much greater than that of the pristine PPy (1:1) of 8.54 m2/g. The performance of PPy-based adsorbents towards the adsorption of MO and CV dyes were investigated by the batch method. PPy-based adsorbents were prepared via chemical oxidative polymerization in the presence of FeCl3.6H2O, anhydrous FeCl3, and (NH4)2S2O8 as oxidants, respectively. Different adsorption parameters such as contact time, adsorbent dose, initial dye concentration and solution pH on the adsorption efficiency of dye removal were explored. The maximum adsorption efficiency of both MO and CV dyes were exhibited using 1:1 mole ratio of monomer to oxidant. The findings confirmed higher dye removal potential in the presence of anhydrous FeCl3 and ammonium persulfate as the oxidant for the MO and CV dye, respectively. The PPy-PEI composite adsorbent has exhibited high adsorption efficiency compared to the pristine PPy adsorbent for the removal of MO and CV dye from aqueous solution. The present work reveals that the incorporation of PEI with Py monomer as a new conducting polymer composite improved the adsorption efficiency of the anionic MO and the cationic CV dyes in aqueous solution. Removal performance was obtained to be 79.1 % and 98.8 % for 100 ppm MO dye by pristine PPy and PPy-PEI composite adsorbents, respectively, at the optimum conditions; pH 3, adsorbent dosage of 0.1 g and with a contact time of 120 minutes. On the other hand, the removal performance for 100 ppm CV dye by pristine PPy and PPy-PEI composite adsorbents was to be 45.0 % and 70.9 %, respectively, at optimum conditions; pH 11, adsorbent dosage of 0.3 g and contact time of 180 minutes. It was observed that the PPy-based adsorbents presented high adsorption performance toward MO than CV dye. Adsorption kinetics was best described by the pseudo-second-order rate model for both dyes. The isotherm study manifested that the Langmuir model was best fitted to the equilibrium data of MO and CV dyes with the maximum monolayer sorption capacity of 232.56 and 142.86 mg/g, respectively at 27 ℃. A regeneration study showed that PPy-PEI could be reused efficaciously for up to three consecutive adsorption-desorption cycles. The combined benefits of facile synthesis and good adsorption potential towards cationic and anionic dyes along with ease of preparation make PPy-PEI a novel adsorbent
Transition metal phosphorus trichalcogenide (MPX3) as saturable absorber for mode-locked thulium-doped fluoride fiber laser / Azim Danial Azam
No full textIn this work, the performance of three materials from the transition metal phosphorus trichalcogenide family (MPX3) for generation of mode-locked pulses in the optical S-band region using thulium-doped fluoride fiber (TDFF) as gain medium were investigated. The advancement of technology and rise of industrial revolution 4.0 brings about a bigger need for ultrafast long-range telecommunication. The current use of C-band and L-band optical telecommunications are quickly being saturated. To encounter this, one prospect is to expand into the S-band. As such, major advancements of optical amplification technology for S-band is required. Generation of laser in S-band region was usually achieved by Erbium-doped fiber (EDF) as the gain medium. However, the high phonon loss of silica fiber in S-band reduces its efficiency. The alternative of this is the ZBLAN glass or known as fluoride glass. When doped with Thulium, this gain medium emits at 1500 nm wavelength when pumped with 1400 nm laser source. This is right within the S-band region. Furthermore, the low phonon loss of fluoride glass makes the laser system more efficient. Mode-locked pulse generation in the S-band region can be achieved through active or passive means. Passive pulse generation is comparatively simpler and cheaper than active in order to obtain megahertz repetition rates and picosecond pulse width. Previous studies have used semiconductor-based saturable absorber (SESAM) and carbon-based SA such as graphene. The use of MPX3 material as saturable absorber is interesting as these materials have been proven in semiconductor and energy storage applications. The proposed laser system can shed light on the practicality of a new class of 2D material as a viable optical material in wide variety of photonics applications
Crossover dynamics of tunable quantum walk in noisy channels / Nur Izzati Ishak
No full textThis study investigates the crossover dynamics of a one-dimensional discrete-time quantum walk (DTQW) in noisy environments using the density matrix formalism and Kraus operator representation of quantum operations. Decoherence is modeled by bit-flip, dephasing, and bit-phase noise channels, while dissipation is represented by generalized amplitude damping channels. The analysis of crossover dynamics involves examining the probability distribution, scaling exponent of variance, coherence measures, and entropy metrics such as Shannon and von Neumann entropy. The DTQW produces a symmetrical probability distribution of displacement under decoherence, with distinct features in scaling exponents of mean squared displacement or variance. Under dissipation, DTQW produces a non-symmetric probability distribution and spreads faster than classical walk under extreme decoherence. These suggest a broad class of crossover transport behavior, which can be classified as pure quantum walk, quantum-like walk, semi-classical-like walk, and classical-like walk. Remarkably, maximum Shannon entropy is achieved at lower degrees of decoherence. This study also analyzes the effect of temporal disorder in the coin operator modeled using fractional Gaussian noise (fGn). The crossover dynamic occurs in the form of weak localization, followed by enhanced entanglement and information backflow. Notably, the correlation of fGn is transferred to the coin's degree of entanglement and transpires in the two-point correlation of the von Neumann entropy fluctuation. These findings can be useful for implementing DTQW-based protocols in quantum error correction, quantum cryptography, and quantum memory on the noisy intermediate-scale quantum (NISQ) platform
Marangoni convection and heat transfer of wavy trapezoidal and C-shaped enclosures filled with nanofluid / Sharifah Nuriza Syed Muhammad Naquib Al‘Aidrus
No full textThe Marangoni effect is a type of natural convection that takes into consideration the surface tension gradient of the interface between two fluids where heat and mass move along it. The effect has many different applications including in microgravity, crystal growth, welding and cooling of electronic components. The present study considers this problem in a wavy trapezoidal and C-shaped enclosures filled with nanofluid. One side of the cavity is heated with the temperature profile varied while the opposite side is cooled at constant temperature. The governing equations which are the continuity, momentum and energy equations, are then derived and non-dimensionalied in order to simplify the system. The equations are then solved using COMSOL 5.3a which utilizes the Galerkin approach of the finite element method and the domain is discretised into fine triangular elements. The approximate solutions obtained are then graphically presented as streamlines, isotherms, local Nusselt and average Nusselt numbers. The general observation made from the outputs is that fluid flow and heat transfer increase with the Marangoni and Rayleigh number. In addition, the wavy wall also helps with temperature distribution when the wavelength is incremented. Furthermore, constant heating performs significantly better than the sinusoidal temperature profile. Applications of this study can be in heat exchangers and building insulation
Kecenderungan pembelian terhadap produk bertanggungjawab sosial dalam kalangan generasi muda Muslim di Malaysia / Nurul Iffah Mohammad Afandi
No full textKajian mengenai kecenderungan pembelian produk bertanggungjawab sosial banyak bertumpu kepada kecenderungan keseluruhan pengguna dan tidak memberi fokus kepada pengguna Muslim. Unsur keagamaan khususnya Hablumminallah dan Hablumminannas juga tidak diberi perhatian dalam mengkaji mengenai kecenderungan pembelian produk bertanggungjawab sosial. Oleh itu, kajian ini dilakukan bagi mengenal pasti kecenderungan pembelian produk bertanggungjawab sosial dalam kalangan pengguna Muslim generasi muda di Malaysia berdasarkan elemen Hablumminallah dan Hablumminannas serta kesan demografi pengguna tersebut dalam mempengaruhi pembelian mereka. Kajian ini penting bagi membantu syarikat pengeluar produk mengetahui faktor dan elemen yang dianggap penting dalam mempengaruhi pembelian pengguna Muslim generasi muda di Malaysia. Edaran soal selidik telah digunakan dan sebanyak 437 borang telah dianalisis menggunakan perisian SPSS. Ujian-T, ANOVA serta korelasi Pearson telah digunakan bagi menganalisis dan membuktikan hipotesis kajian. Analisis yang dijalankan menunjukkan bahawa kebanyakan faktor demografi (jantina, peringkat pengajian dan zon pengajian) adalah tidak signifikan dalam mempengaruhi kecenderungan pembelian produk bertanggungjawab sosial. Manakala faktor bidang pengajian dan urbaniti pula hanya mempunyai kesan yang signifikan kepada sebahagian kecil faktor pembelian. Dapatan kajian juga menunjukkan bahawa pengguna lebih mementingkan elemen Hablumminannas daripada Hablumminallah walaupun kedua-dua elemen tersebut mempunyai hubungan yang positif. Daripada analisis elemen Hablumminannas sendiri pula, pengguna menunjukkan penekanan yang ebih mendalam kepada dimensi produk berorientasikan manusia (produk bertanggungjawab komersial dan produk bertanggungjawab komuniti) berbanding dengan dimensi produk bertanggungjawab terhadap alam sekitar dan ekosistem walaupun ketiga-tiga dimensi tersebut turut mempunyai hubungan yang positif
Social intervention framework regarding ecological factors pertaining to academic achievement of pregnant teenagers in Nigeria / Otegbayo Bolajoko Elizabeth
No full textAdolescent pregnancy is one of the major causes of school dropout among pregnant teenagers in Nigeria. Despite the numerous studies that have been conducted on the issue and the policies that have been developed on the issue, more and more adolescent girls are vulnerable to unwanted pregnancies. In addition, there are no comprehensive intervention measures to support pregnant adolescents of school age, which is believed to increase the educational deficit of pregnant adolescents and the female population in Nigeria. For this reason, it is important to develop a social intervention framework that can help improve the academic performance of pregnant adolescents and reduce the rate of unintended pregnancies in Nigeria. To develop a social intervention framework, it is therefore important to examine the relationship between environmental factors and adolescent girls' school performance. This can help to identify the key ecological factors that influence the academic success of pregnant female students in Nigeria. The main objective of this study was therefore to develop an intervention framework that can be used to improve the academic performance of pregnant female students and minimise the consequences of unwanted pregnancies among adolescent girls. To achieve this goal, the study examined the respondents' level of ecological factors and explored the relationship between ecological factors (sexual and reproductive health knowledge, sexual attitudes, substance abuse, alcohol abuse, peer attachment, parental attachment, living environment, neighbourhood, cultural values, and religious beliefs) and the academic performance of pregnant teenagers. Subsequently, the results of the study were used as the basis for developing a holistic social intervention framework for pregnant school-age teenagers.
This was a cross-sectional study of pregnant teenagers aged 15-19 years who were enrolled in school. Data for the study were collected using a structured, self-completed questionnaire. Descriptive analysis was used to examine the ecological status and academic achievement of the participants and structural equation modelling (SEM) was used to assess the relationship between ecological factors and academic achievements. The results showed that the level of most of the ecological factors examined in this study was risky. It was found that 49.3% of the respondents had inadequate sexual reproductive health knowledge and awareness and 60% of the respondents had poor sexual attitude. In addition, 21% showed high risk for drugs and 38.3% showed high risk for alcohol abuse. Meanwhile, 32.8% had low attachment with peers and 38% had low attachment with parents. Further, 57.3% lived in a substandard housing environment and 71.3% reported living in a poor neighbourhood. In addition, 57.3% were not practicing good cultural values and 28.7% had a negative religious belief. In terms of academic performance, 38% of the respondents had a CGPA of less than 2.5, 36% had a CGPA between 2.5-3.5 and 25% had a CGPA above 3.5. In addition, the result of the SEM analysis (relationship between environmental factors and academic performance) showed that knowledge of sexual and reproductive health (β =0.204, p < 0.001), sexual attitude (β =0.055, p < 0.091), alcohol abuse (β =-0.084, p=0.029), substance abuse (β=-0.086, p0.008), parental attachment (β =0.195, p < 0.001) and peer attachment (β =0.152, p < 0.001), religious belief (β =0.173, p < 0.001), cultural value (β=-0.352, p < 0.001), housing environment (β =0.135, p < 0.006) and neighbourhood (β =0.368, p < 0.001) had significant association with academic achievements of pregnant respondents. Thus, the analysis of variance revealed that 63.9% of the pregnant respondents' academic achievements depended on all the ecological factors examined in this study. Based on these findings, the study developed a social intervention framework for ecological factors as a recommendation for developing intervention program to improve the academic achievement of pregnant teenage students. The social intervention framework was developed using the six steps of the Quality Intervention Development Framework (6SQuID). Guided by research findings, this social intervention framework is designed to help identify key areas that influence the academic achievement of pregnant teens. This framework can help researchers, policymakers, and other key stakeholders develop intervention programs that can promote academic achievement and curb school dropout and the consequences of teen pregnancy. It can be used with pregnant and non-pregnant adolescents, parents, and peers. It includes a range of intervention programmes that can promote lifestyle change, effective communication, buffering negative cultural norms and improving sexual and reproductive health literacy. In summary, these findings can serve as a basis for decision-making and formulating strategies that benefit pregnant teenagers by improving their academic performance
Stres dalam amalan pemulihan oleh pengamal pemulihan kes penyelewengan agama di Selangor / Nur Akmal Zakiah Ahmad
No full textSetiap profesion pekerjaan tidak akan terlepas daripada berhadapan dengan tekanan kerja. Begitu juga profesion pengamal pemulihan yang memerlukan komitmen tinggi kepada usaha-usaha rehabilitasi sudah pasti memberikan tekanan tertentu kepada golongan ini. Oleh yang demikian, tujuan kajian ini dilakukan adalah untuk mengenalpasti faktor tekanan yang dihadapi oleh pengamal pemulihan dalam kes penyelewengan agama di Selangor. Selain itu, pengkaji juga ingin mengetahui pendekatan yang diambil oleh pengamal pemulihan dalam menangani tekanan yang dihadapi mereka. Seterusnya pengkaji ingin mengetahui sejauh mana implikasi tekanan mempengaruhi pembangunan diri yang positif terhadap profesional pengamal pemulihan. Kajian ini berbentuk kualitatif dengan sampel informan yang terdiri daripada lima orang pengamal pemulihan yang menjalankan perkhidmatan tolong bantu pelatih yang terlibat dalam kes penyelewengan agama di Selangor. Pengutipan data dijalankan melalui kaedah temubual mendalam dan data kajian dianalisis secara tematik. Hasil kajian menunjukkan bahawa terdapat beberapa faktor yang menyebabkan tekanan dalam kalangan pengamal pemulihan antaranya faktor bebanan kerja dan tuntutan pekerjaan, kurang kompetensi dan ilmu pengetahuan, sikap pelatih dan gangguan luar. Berdasarkan dapatan yang diperolehi juga mendapati antara pendekatan yang diambil oleh para pengamal pemulihan bagi menangani tekanan adalah melalui amalan agama dan kerohanian, sokongan sosial, aktiviti kegemaran dan persekitaran yang sihat. Dari sudut lain, kajian juga mendapati bahawa berlakunya pembangunan positif dalam diri pengamal pemulihan daripada sudut ilmu pengetahuan, kemahiran dan kerohanian. Akhir sekali, kajian dapat mengenal pasti bahawa tekanan mempengaruhi pembangunan diri pengamal secara positif dan negatif
Representasi pelarian Syria dalam laman web al Jazeera Arab dan BBC Arab dengan menggunakan analisis wacana kritikal / Syahirah Almuddin
No full textPelarian sering digambarkan secara negatif di dalam media. Beberapa stereotaip mengenai pelarian dapat dilihat dalam gambaran media iaitu: terlibat dengan jenayah, berstatus haram, sebagai ancaman kepada identiti negara dan ekonomi. Jika dilihat, kebanyakan kajian yang telah dibuat melibatkan pelarian dari negara dan bangsa yang berlainan. Namun begitu, kajian ini dibuat bagi memberikan gambaran yang lebih jelas bagaimana representasi pelarian Syria dipaparkan dalam artikel berita al-Jazeera selaku wakil kepada bangsa Arab dan BBC sebagai wakil orang luar. Objektif utama kajian ialah mengenalpasti cara representasi pelarian Syria dalam al-Jazeera dan BBC, mengenalpasti aspek intertekstualiti dan interdiskursitiviti yang mempengaruhi representasi pelarian Syria dalam al-Jazeera dan BBC dan menjelaskan amalan sosial yang disampaikan melalui laporan kedua-dua laman berita al-Jazeera Bahasa Arab (AJA) dan BBC Bahasa Arab (BBCA). Kajian ini menggunakan pendekatan Model Tiga Dimensi analisis wacana kritikal (CDA) Fairclough (1992), yang merangkumi 3 dimensi, iaitu teks, amalan wacana dan amalan sosial. Model ini digunakan untuk menganalisis korpus yang mengandungi 100 topik berita mengenai Pelarian Syria dari tahun 2013 sehingga 2015 dari kedua-dua laman berita al-Jazeera (50 artikel) dan BBC (50 artikel). Dapatan menunjukkan terdapat empat representasi yang sering dikaitkan dengan pelarian Syria melibatkan: (i) pelarian sebagai pelarian, (ii) pelarian sebagai angka, (iii) pelarian sebagai mangsa dan (iv) pelarian sebagai orang yang memerlukan bantuan. Kajian ini mendapati terdapat perspektif yang berbeza terhadap pelarian Syria oleh bangsa Arab yang diwakili oleh al-Jazeera dan masyarakat luar yang diwakili oleh BBC. Al-Jazeera dilihat lebih beremosi melalui pemilihan perkataan yang digunakan ketika melaporkan kesusahan pelarian. Al-Jazeera dan BBC menyampaikan berita mewakili negara Arab dan negara Eropah. Negara Arab seperti Qatar tidak ditonjolkan sebagai negara yang menerima pelarian. Manakala BBC merupakan pihak yang terlibat dengan isu kemasukan pelarian ke Eropah. Hal ini telah membentuk corak laporan antara dua buah badan berita yang mengalami pengalaman yang berbeza dengan isu pelarian
Assessment of the technological dimension in the industrial and development policies in Malaysia / Mohammad Ikmal Kadir Mohd Arshad
No full textThis research examined the impact of Malaysia's Industrial Policies on technological advancement and economic growth within the context of the country's heavy dependence on industrialisation, particularly its manufacturing sector. The study aimed to address the lack of coordination and continuity in policy implementation, which led to overlapping initiatives and hindered the effective realisation of technological advancements. The research problem revolved around the challenges posed by disjointed policy plans and the subsequent impact on the advancement of technological capabilities. Through an in-depth qualitative approach, the study analysed Malaysia's industrial policies from 2006 to 2020, encompassing key plans like the Third Industrial Masterplan, Ninth Malaysia Plan, Tenth Malaysia Plan, Eleventh Malaysia Plan, and National Key Economic Areas. The research methodology involved reviewing relevant literature, comparative analysis of policies, and the development of an assessment framework focusing on technological dimensions. The analysis revealed that while the policies consistently emphasised human capital development, there were variations in execution strategies. Despite the focus on technological advancement, the productivity growth of Malaysia's economy remained inconsistent. The manufacturing sector, especially the Electrical and Electronics (E&E) industry, faced challenges with a high demand for low-skilled labour, contrary to the goal of fostering high-skilled technology-savvy employment. The lack of coordination between policy plans hindered private sector involvement in technological development. The policies often initiated programs without proper alignment with previous plans, leading to a lack of clear strategies for empowering the private industry. This lack of continuity impacted the transition to higher technological capabilities within industries, raising doubts about the effectiveness of policies intended to involve the private sector in technological advancements. The study also found that overlapping policies resulted in redundant resource allocation and hindered the growth of crucial sectors like E&E. This lack of coordination contributed to inconsistent contributions to GDP from technology-focused sectors. For example, the contribution of telecommunication services significantly declined despite the emphasis on private sector industries during the tenth Malaysia plan. To address these issues, the study recommended a comprehensive assessment of the technological dimensions of industrial policies. It highlighted the importance of aligning policies and overcoming overlapping initiatives to effectively promote technological advancement and sectoral growth. The research underscored the necessity of addressing challenges related to private sector empowerment and policy coordination. Overall, this research shed light on the complexities of Malaysia's industrial policies and their impact on technological advancement and economic growth. By identifying issues related to coordination, alignment, and private sector involvement, the study provided insights that can contribute to more effective policy formulation and implementation in the future
Hubungan kekerabatan dialek Melayu Sarawak, Malaysia dan dialek Melayu Midai, Indonesia / Akhmal Hakim Mohamad
No full textKajian ini menekuni bidang linguistik bandingan bagi meneliti Dialek Melayu Sarawak (DMS) dan Dialek Melayu Midai (DMM). Kajian dijalankan bagi mengenal pasti tingkat kekerabatan antara DMS dengan DMM berdasarkan kaedah leksikostatistik yang dipelopori oleh Morris Swadesh (1950). Kemudian, kajian dilanjutkan dengan menghuraikan bentuk variasi fonem yang terdapat dalam kedua-dua dialek yang dikaji berpandukan Teori Struktural. Kajian menggunakan senarai 230 Kata Morris Swadesh yang diubah suai untuk menemu bual informan (pemaklum). Dapatan kajian mendapati bahawa tingkat kekerabatan dialek adalah sebanyak 78.85% dan berada dalam status keluarga. Selain itu, kajian juga mendapati bahawa DMS memiliki enam fonem vokal (/i/, /e/, /a/, /ə/, /u/ dan /o/), satu diftong (/-oy/) dan 20 konsonan (/p/, /t/, /k/, /q/, /ʔ/ /b/, /d/, /g/, /č/, /ǰ/, /m/, /n/, /ɲ/, /ŋ/, /s/, /ɣ/, /h/, /l/, /w/ dan /j/). DMM pula mempunyai tujuh fonem vokal (/i/, /e/, /a/, /ə/, /u/, /o/ dan /ɔ/), tiga diftong (/-ay/, /-uy/ dan /-aw/) dan 21 fonem konsonan (/p/, /t/, /k/, /q/, /ʔ/ /b/, /d/, /g/, /č/, /ǰ/, /m/, /n/, /ɲ/, /ŋ/, /s/, /ɣ/, /h/, /r/, /l/, /w/ dan /j/). Di samping itu, kajian telah menemukan dua bentuk kesepadanan bunyi, iaitu lima bentuk kesepadanan vokal (/i/ ≈ /e/, /a/ ≈ /o/, /a/ ≈ /ə/, /a/ ≈ /ɔ/ dan /u/ ≈ /o/) dan enam bentuk kesepadanan konsonan (/r/ ≈ /ɣ/, /ʔ/ ≈ /q/, /ʔ/ ≈ /h/, // ≈ /n/, /q/ ≈ /t/ dan /m/ ≈ /n/)