The objective of this study is to extract, isolate, and elucidate the indole alkaloids from the roots of Kopsia singapurensis Ridl. collected from Kluang, Johor. The extraction process of the plant was carried out using hexane followed by dichloromethane (DCM) to yield hexane and DCM crude extracts. The isolation and purification process were performed by various chromatographic techniques namely column chromatography (CC), thin layer chromatography (TLC) and preparative thin layer chromatography (PTLC). The structures of isolated compounds were elucidated by using spectroscopic methods such as 1D-NMR (1H, 13C, and DEPT 135?) and 2D-NMR (COSY, HMQC, and HMBC), ultraviolet (UV), infrared (IR) and mass spectrometry (MS), and also by comparison with previous works. This study has successfully isolated eight indole alkaloids from the roots of K. singapurensis Ridl., tetrahydroalstonine, melodinine E, kopsifine, rhazinicine, kopsamine N(4)-oxide, aspidodasycarpine, kopsamine, and akuammidin.....

458 hits

Kajian ini bertujuan untuk membangun perisian multimedia bagi pengajaran dan pembelajaran berbantu komputer serta menilai keberkesanannya terhadap pencapaian murid bermasalah pendengaran dalam mata pelajaran Pembantu Penyedia Makanan. Dalam proses pembangunan, kebolehgunaan perisian multimedia diuji dan dinilai oleh enam orang guru mata pelajaran Pembantu Penyedia Makanan dengan menggunakan borang penilaian. Keberkesanan perisian multimedia pula diuji dengan menggunakan reka bentuk kajian eksperimen kuasi yang mana dua kaedah pengajaran dan pembelajaran berbeza dilaksanakan iaitu kaedah konvensional bagi kumpulan kawalan dan kaedah berbantu komputer bagi kumpulan rawatan. Data pencapaian murid dikumpul dengan menggunakan ujian pra dan ujian pasca. Seramai enam orang murid Tingkatan 5 Pembantu Penyedia Makanan dipilih sebagai sampel dan dipecahkan kepada dua kumpulan, iaitu tiga orang dalam kumpulan kawalan dan tiga orang dalam kumpulan rawatan. Data kajian dianalisis dengan menggunakan.....

881 hits

The purpose of this research is to produce the formulas of the homological functors of some Bieberbach groups of dimension ?ve with dihedral point group of order eight. The homological functors consist of the nonabelian tensor square, G-trivial subgroup of the nonabelian tensor square, the central subgroup of the nonabelian tensor square, the nonabelian exterior square and Schur multiplier. The computational method for polycyclic groups is used to determine the formulas of the functors. Selected theorems, lemmas and de?nitions are also used in the computation. The ?findings of this research are the new formulas of the homological functors and also the generalization of one of the functors that is the central subgroup of the nonabelian tensor square. As a conclusion, the nonabelian tensor square and the nonabelian exterior square are found to be not abelian. While G-trivial subgroup of the nonabelian tensor square, the central subgroup of the nonabelian tensor square and Schur multiplie.....

2313 hits

Kajian ini bertujuan menilai pemahaman konsep Jirim dan Haba dalam kalangan murid sekolah rendah. Kaedah kuantitatif yang digunakan dalam kajian ini melibatkan 289 murid sebagai responden daripada enam buah sekolah rendah di sekitar Selangor dan Perak. Instrumen yang digunakan ialah dua set soalan ujian bagi tajuk Jirim dan Haba yang setiap satunya mengandungi enam item soalan terbuka. Dapatan kajian menunjukkan bahawa tahap prakonsepsi murid-murid Tahun Tiga berada di tahap tinggi bagi konsep Jirim dan Haba. Walaubagaimanapun, bagi murid- murid Tahun Lima, tahap miskonsepsi adalah sederhana. Hasil kajian juga mendapati kebanyakan murid mengalami kesukaran dalam menerangkan sifat jirim, menjelaskan perubahan fasa yang berlaku terhadap jirim serta mendefinisikan konsep haba. Kesimpulannya, miskonsepsi dalam kalangan murid Tahun Lima terhadap tajuk Jirim dan Haba masih kekal walaupun mereka telah mempelajari tajuk ini selama dua tahun. Implikasi kajian adalah guru seharusnya cuba sedaya .....

1718 hits

The aim of this research is to study the efficiency of the order-2 extrapolated implicit Runge-Kutta methods. The order-2 methods being considered are the implicit midpoint (IMR) and implicit trapezoidal (ITR) rules. These methods are applied with the polynomial and rational extrapolations actively and passively with smoothing to improve the accuracy. In order to reduce the round-off errors, a technique known as compensated summation with simplified Newton is implemented in all the numerical codes. The results are given based on numerical experiments that are carried out using MATLAB software. The findings showed that passive polynomial extrapolation by the IMR and ITR are more efficient than with active and passive rational extrapolation. The smoothing technique with extrapolation by the IMR and ITR gives better behavior than without the smoothing technique. It is therefore concluded that in solving chemistry, linear and nonlinear chemical and logistic curve problems, passive polynomi.....

767 hits

The purpose of this study was to determine the effectiveness of an interactive geometry software program, Geometer’s Sketchpad (GSP), in the teaching and learning of mathematics among technical schools’ students. The quasi-experimental study was conducted on 56 students from a randomly selected technical school. The students were assigned into a controlled and an experimental group using cluster (class-based) random sampling. The control group received conventional teaching method while the experimental group was taught using a GSP module on a chosen topic namely Trigonometric Functions for the duration of 8 weeks. Three sets of tests, which are pre-test, post-test and retention-test were administered to both groups of students in weeks 1, 8 and 10, respectively. Besides the tests, a set of questionnaires and an interview protocol were used in collecting the empirical data. The results of tests and questionnaires were analysed using descriptive and inferential statistics such as me.....

1818 hits

Kajian ini bertujuan menentukan kesan penggunaan kaedah Suai Gabung Graf (SGG) terhadap kemahiran di dalam topik Gerakan Linear dalam Fizik Tingkatan Empat. Pendekatan kuantitatif digunakan dengan kaedah eksperimen kuasi. Skor pelajar dikumpul dengan menggunakan Penilaian Kemahiran Menggraf Gerakan Linear (PKM). Instrumen tersebut ditadbirkan dalam dua sesi pengujian iaitu praujian dan pascaujian yang setara. Perbandingan min skor pelajar dianalisis menggunakan ujian-t. Seramai 197 orang pelajar Tingkatan Empat telah dipilih sebagai sampel dan dipecahkan kepada dua kumpulan iaitu 101 orang dalam kumpulan kawalan dan 96 orang dalam kumpulan ujikaji. Hasil kajian menunjukkan tahap kemahiran menggraf gerakan linear kedua-dua kumpulan menunjukkan peningkatan yang signifikan. Namun begitu, tiada perbezaan yang signifikan antara min skor pascaujian kedua-dua kumpulan tersebut. Kesimpulannya, kaedah SGG memberikan kesan interaksi positif yang lebih tinggi terhadap kemahiran menggraf gerakan l.....

1069 hits

Kajian ini bertujuan untuk meneroka penggunaan Model Refleksi Evolusi dalam pengajaran. Reka bentuk kajian kes digunakan untuk meneroka secara mendalam proses pemikiran guru semasa melakukan refleksi berdasarkan Model Refleksi Evolusi. Data dikumpul melalui temu bual sebelum pengajaran dan selepas pengajaran, pemerhatian pengajaran dan penelitian dokumen. Seramai 12 orang guru bahasa yang terdiri daripada 4 orang guru Bahasa Melayu, 4 orang guru Bahasa Inggeris dan 4 orang guru Bahasa Tamil. Dapatan kajian menunjukkan bahawa Model Refleksi Evolusi merangsang pemikiran guru-guru bahasa untuk mengamalkan refleksi secara sistematik ke arah mempertingkatkan kemahiran mengajar mereka. Guru-guru yang mengamalkan secara berurutan langkah-langkah Model Refleksi Evolusi didapati lebih sistematik dalam membuat perancangan mengajar, pemilihan strategi pengajaran, pemilihan bahan, membuat penerangan dan membuat penilaian. Manakala guru-guru yang mengamalkan langkah-langkah secara tidak berurutan M.....

2122 hits

The purpose of this study was to determine the underlying constructs of an instrument to measure self-regulated learning (SRL), examine the correlation between SRL and academic performance, determine the SRL predictors of academic performance and how gender and age moderated this relationship among nontraditional learners (n=519) in the Primary School Graduate Program (PGSR). Factor analyses, Pearson bivariate correlation, linear regression analysis and moderated multiple regression analyses were performed. Additionally, this study examined the barriers to learning and how SRL could be utilized to resolve these barriers. The items in the Self-Regulated Learning Questionnaire (Sf-ReLQ) was found to comprise a robust scale. Findings revealed that there was a moderately significant relationship between SRL and academic performance. An intriguing finding was the insignificant negative correlation of time study management and academic performance. Overall results of the multiple regression .....

685 hits

Kajian ini melibatkan dua peringkat, iaitu kajian awal secara tinjauan dan kajian eksperimen. Terdapat tiga (3) tujuan kajian awal iaitu; Pertama, mengukur tahap stres secara keseluruhan; Kedua, mengukur tahap elemen-elemen simptom stres iaitu Somatizasi (SOM), Obsesif- Kompulsif (OC), interpersonal-Sensitiviti (IS), Kemurungan (DEP, Kebimbangan (ANX), Permusuhan (HOS), Fobia (POB), Pemikiran Paranoid (PAR), Psikotisme (PSY) dan Dimensi Tambahan (AD); dan Ketiga, mengukur tahap stres keseluruhan berdasarkan daerah bertugas dalam kalangan staf Jabatan Kebajikan Masyarakat (JKM) negeri Johor. Kajian awal melibatkan subjek kajian seramai 240 orang (120 lelaki; 120 perempuan) dipilih secara persampelan rawak berstrata. Data dikumpul menggunakan Inventori Simptom SCLR-R-90 (Symptom Inventory version of the SCL-R-90) dan dianálisis secara perbandingan peratusan dan min. Dapatan kajian tinjauan menunjukkan 23% subjek mengalami tahap stres yang tinggi. Antara elemen stres pula menunjukkan tah.....

893 hits