For decades, solar energy as one of the endless energy sources has become the most public preference as a means to accommodate space heating. Various studies on solar thermal technologies have been worked out to replace outdated systems. However, conventional solar thermal systems offer two drawbacks such as diffuse solar radiation conditions that can lead to insufficient heating during winter and autumn, and limitations of the solar collector orientation that need to be opposed at a correct tilted angle towards maximizing the performance of the system. Previous studies have proposed an integrated design that consists of the evacuated tube and a preheating double-pass flow thermal absorber arrangement, namely, Evacuated Glass-Thermal Absorber Tube Collector (EGATC) to overcome these problems. Therefore, this research has discussed further on the formulated mathematical modeling of the design. EGATC components used to convert solar radiation into heat that stabilized and increased the o.....

217 hits

A new flavonoid, 7,3ˊ-dihydroxy-3,5,4ˊ-trimethoxyflavone, along with two known flavonoids, 7-hydroxy-5,4ˊ-dimethoxyflavone and 7-hydroxy-3,5,4ˊ-trimethoxyflavone were isolated from the leaves ethyl acetate extract of Eusideroxylon zwageri Teijsm. & Binn. (Lauraceae). Structures were elucidated by spectroscopic techniques such as NMR, IR, and Orbitrap Mass Spectrometry. Keywords: Eusideroxylon zwageri, Lauraceae, flavonoid..

387 hits

This study aims to develop and evaluate the effectiveness of the I-Algebra module, which employed the Normative Algebra Strategy (NAS). The development of the module was based on the adaptation of the Sidek model. The study also analyses the effect of the module on year five pupils' achievement and motivation. Quantitative approaches with the quasi-experimental design used for this study. Module was developed based the two phases stated in Sidek model, first phase is the draft phase of the module and the second phase is the phase that tries and evaluates the module. The module was evaluated by a panel of three experts to determine the content validity of the module. To determine the reliability and effectiveness of I-Algebra module, a pilot study was conducted which involved 30 year five pupils. The respondents were chosen using cluster sampling methods where they were divided equally into the treatment and the control groups. Data were analysed using SPSS software version 25 for infer.....

265 hits

Bridelia ferruginea (Benth., Euphorbiaceae), prominently found in Savannah regions, is commonly used as an ethnomedicine for the treatment of several ailments in many parts of Africa. Piliostigma thonningii (Schum., Fabaceae) is used for various medicinal purposes in African countries with some pharmacological activities established from the crude extracts including antibacterial, antihelminthic, antiinflammatory and antilipidemic activities. In the present study, crude methanolic extract and fractions of B. ferruginea and P. thonningii were examined for their phytochemical constituents and antioxidant activity using standard protocols. Qualitative phytochemical screening of B. ferruginea crude extract revealed the presence of tannins, saponins, phlobatanins, flavonoids, steroids, alkaloids, glycosides, phenols and resins while it tested negative for triterpenoids, carbohydrates, terpenoids and anthraquinones; the quantitative phytochemical analysis showed that it contained 1.5% saponi.....

412 hits

The essential oil of Litsea resinosa Blume (Lauraceae) was obtained by hydrodistillation and was fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of twenty-eight components were identified in the essential oil, which made up 90.8% of the total oil. The essential oil consists mainly of β-caryophyllene (22.5%), α-humulene (15.4%), caryophyllene oxide (9.2%), germacrene D (5.6%), and β-selinene (5.0%). The essential oil showed significant activity against acetylcholinesterase with a percentage inhibition of 72.4%. Keywords: Litsea resinosa, Lauraceae, essential oil, caryophyllene, acetylcholinesterase..

340 hits

Previous studies have reported the use of nitrogen-heterocyclic compounds to treat malaria. Interestingly, quinolone and 1,2,4-triazole scaffolds demonstrated an outstanding capacity to target at least two stages of the malaria parasite life cycle, especially when they are hybrid with other nitrogen heterocycles. Thus, the objective of this study is to assess the drug susceptibility of Plasmodium knowlesi A1H1 parasites to certain 1,2,4-triazoles and benzoquinones that bear pyrrolidinones using a plasmodium lactate dehydrogenase assay. All synthesized compounds showed moderate activity against P. knowlesi A1H1 with EC50 values in the range of 13.39-28.85 μM. Both 1,2,4-triazoles and quinolone derivatives were synthesized using commercially available pyrrolidinones. Keywords: 1,2,4-Triazoles; quinolones; antimalarial, Plasmodium knowlesi A1H1..

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This paper presents the simulation of numerical solutions to the navigational problem of an agent traveling safely in its environment. The approach is based on the numeric solutions of the boundary value problem (BVP) that generate harmonic potential fields through a differential equation whose gradient represents navigation routes to the destination. Two methods, namely KSOR and KAOR, were tested to solve the BVP. KSOR and KAOR are variants of the standard SOR and AOR methods, respectively. In this work, the KSOR and KAOR methods were used to solve the BVP by applying Laplace's equation to obtain harmonic functions. The generated harmonic functions are then utilized by the searching algorithm to find a smooth navigational route for an agent to travel in its environment without colliding with any obstacles. The numerical results from the solutions of BVP demonstrate that the KAOR provides a faster execution time with fewer iterations compared to the KSOR method. Keywords: KSOR, KAOR, .....

426 hits

The objectives are to derive the stability analysis theoretically and to set up the stability analysis numerically for radiation effects on Marangoni convection boundary layer over a permeable surface. The stability analysis is used to determine which branch solutions are stable and physically realisable. The stability can be tested via the smallest eigenvalue. Negative smallest eigenvalue produces an initial growth of disturbance and the flow becomes unstable. In contrast, the positive smallest eigenvalue results in an initial decay of the disturbance, thus the flow is stable. The research has an implication in order to identify which solution is stable, whether the first or the second solution. Keywords: permeable surface, dual solution, stability analysis..

414 hits

Kajian ini melihat hubungan di antara daya tindak perkahwinan dan personaliti di kalangan 170 orang  (N = 110 wanita, 60 lelaki) subjek yang berkahwin, dan berumur di antara 22 hingga 55 tahun (M =  40.0, SP= 7.82). Bagi tujuan kajian ini, pengkaji menggunakan dua alat ukur iaitu Marital Coping Inventory (Bowman, 1990) sebagai alat ukur  daya tindak perkahwinan dan NEO-Five Factor Inventory (Costa &  McCrae, 1992) bagi melihat  personaliti.  Dimensi daya tindak adalah konflik, menyalahkan diri, mementingkan diri, pendekatan  positif dan pengelakan. Manakala  personaliti  pula  merangkumi  neurotik,  ekstrovert,   keterbukaan, kebersetujuan dan ketekunan. Analisis kajian menunjukkan wujudnya hubungan di antara   beberapa  dimensi  personaliti  dengan  daya  tindak.  Hanya  dimensi mementingkan diri tidak  mempunyai hubungan dengan personaliti. Pengkaji turut melihat perbezaan daya tindak mengikut  jantina, tempoh perkahwinan dan kategori umur. Implikasi.....

295 hits

Kajian mengenai penglibatan ibu bapa telah banyak dijalankan, terutamanya di luar negara. Walau  bagaimanapun, kajian mengenai penglibatan ibu bapa dari aspek psikologi jarang didapati di  Malaysia.  Penglibatan ibu bapa dalam pendidikan anak-anak mereka merupakan aspek penting yang  sering diabaikan. lbu bapa memainkan peranan signifikan dalam proses perkembangan anak-anak mereka.   Kajian ini mengupas penglibatan ibu bapa dari tiga aspek  psikologi  iaitu sokongan emosi,   perapatan dan  jangkaan dan hubungannya dengan kesediaan membaca kanak-kanak pra sekolah.  Kajian  ini adalah satu kajian kes berbentuk kualitatif yang menggunakan kaedah pemerhatian  dan  temubual. Seramai 20 orang pelajar pra sekolah yang berusia lima tahun diberi ujian Konsep Cetakan  untuk menguji kesediaan membaca mereka. Selepas markah diperolehi, 5 pelajar yang mendapat markah tertinggi, sederhana dan terendah dipilih untuk sesi pemerhatian  dan  seterusnya  ibu  dan  bapa  me.....

306 hits