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  1. Farhan Mohd Nor, Rizafizah Othaman
    Sains Malaysiana, 2015;44:875-881.
    A composite membrane was prepared by mixing epoxidized natural rubber (ENR) and polyvinyl chloride (PVC). An
    inorganic filler, MgO, was introduced into the polymer matrix by certain percentages to form a mixed matrix membrane
    (MMM). The resulting membranes were characterized using FTIR, TGA, SEM and gas permeability test. FTIR results showed
    the incorporation of MgO inside the membrane matrix with the appearance of an absorption peak at 3700 cm-1 which
    represents the formation of Mg(OH)2
    . Thermogram from TGA analysis showed two degradation stages at 250-350°C
    and 370-500°C, which correspond to the decomposition of PVC and ENR and the residue of fillers at 600°C. SEM images
    of the membranes showed that pores were developed as fillers were introduced to the membrane. The size of the pores
    also increased with the increase of filler percentage. As for gas permeation test, the permeability values of CO2
    and N2
    for ENR/PVC membrane were the lowest. The permeability values increased with the addition of MgO to the membrane.
    The permeability of CO2
    was also the highest for all membranes.
  2. Nazwa Jon, Ibrahim Abdullah, Rizafizah Othaman
    Sains Malaysiana, 2013;42:469-473.
    The presence of pores plays an important role for many membrane processes especially in ultrafiltration and microfiltration. Epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) membranes filled with two types of silica fillers were prepared via simultaneous solvent exchange and evaporation of solvent technique. Two types of silica, i.e. microsilica (microcrystalline
    silica powder) and nanosilica (generated from tetraethoxysilane (TEOS)) were used. The chemical composition, morphology and mechanical stability of the membranes were studied. Both types of silica showed good interaction with the membrane matrix. The formation of pores depended on the size of silica particles added. Microsilica produced large pores while insitu generated nanosilica produced nanosized pores. The mechanical properties of membrane improved with the addition
    of silica. The tensile strength increased from 10.6 MPa to 17.8 MPa and 14.5 MPa for nanosilica and microsilica filled membrane while the tensile modulus increased from 1.6 MPa to 3.8 MPa and 3.4 MPa, respectively. Thus, both types of silica acted as a filler as well as pore forming agent for the ENR/PVC membrane.
  3. Aina Aqila Arman Alim, Rizafizah Othaman
    Sains Malaysiana, 2018;47:1517-1525.
    Epoxidized natural rubber/polyvinyl chloride/microcrystalline cellulose (ENR/PVC/MCC) composite membranes were
    prepared and used to treat palm oil mill effluent (POME). The loadings of MCC were varied at 0, 5, 10 and 15 w/w%. The
    increment of MCC loads has intensified the hydroxyl peak of the membranes in FTIR spectrum, indicating the increase
    in membrane hydrophilicity. MCC acted as a pore forming agent since the ENR/PVC/10% MCC gave the highest water
    flux and well-distributed pores. After first treatment of POME, the levels of chemical oxygen demand (COD), biochemical
    oxygen demand (BOD) and total suspended solid (TSS) were reduced to 99.9%, 70.3%, and 16.9%, respectively. These
    data showed that ENR/PVC/MCC membrane has the potential to treat POME.
  4. Afifah Muhamad Sidik, Rizafizah Othaman, Farah Hannan Anuar
    Sains Malaysiana, 2018;47:1181-1187.
    The use of biodegradable material in membrane technology will be a great solution in reducing non-biodegradable
    waste in the landfill. Membranes can often be useful as the recycle stream can usually be much cleaner than with other
    techniques. This article describes the preparation of poly(l-lactic acid)-poly(ethylene glycol) (PLLA-PEG) free standing flat
    sheet membranes with the presence of 5 wt. % activated carbon filler. PLLA-PEG crosslinked copolymer was synthesized
    using PLLA with different molecular weight PEG prepolymers i.e. 4000, 6000 and 10000 g/mol; and excess hexamethylene
    diisocyanate to form urethane linkages between the polymers. The reaction was carried out in a dichloromethane/
    tetrahydrofuran dual-solvents system. The PLLA-PEG/AC membranes in the weight ratio of 7:3:0.5 were then fabricated
    using solution casting and phase inversion techniques. The performance of the membranes was evaluated in terms of
    permeation water flux (PWF), palm oil mill effluent (POME) permeation, flux decline and contact angle. It was found that
    membrane containing 10000 g/mol PEG has the highest total mean in PWF, POME flux and hydraulic permeability with
    values of 100.9 L/m2
    .h, 51.45 L/m2
    .h and 64.9º;62.9º, respectively, due to high porosity. All of the membranes were more
    stable towards the flux decline of POME compared to water. At the same time, addition of AC to the copolymer considerably
    enhances the texture and porosity of the fabricated membranes.
  5. Rizafizah Othaman, Kausar Ahmad Fuad, Farhan Mohd Nor, Rozida Mohd Khalid
    Sains Malaysiana, 2016;45:1939-1945.
    Penyelidikan dijalankan bagi menilai kesan penggunaan filem boleh makan dan filem polietilena (PE) sebagai bahan
    penyalut untuk ubi keledek (Ipomoea batatas) goreng. Kepingan ubi keledek disalut dengan lapisan filem boleh makan
    yang terdiri daripada 0.045 g/mL selulosa metil (MC), 0.045 g/mL selulosa hidroksipropil metil (HPMC) dan 0.16 g/mL
    jagung zein (CZ) sebelum digoreng di dalam minyak sawit pada suhu 170-180°C selama 3 min. Manakala ubi keledek juga
    disalut dengan filem tak boleh makan iaitu polietilena (PE) (nisbah PE kepada minyak 1:100 g/g) sebagai perbandingan.
    Ubi goreng tanpa salutan filem digunakan sebagai sampel kawalan. Ciri fizikokimia ubi goreng bersalut dianalisa.
    Keputusan menunjukkan semua filem melekat pada permukaan ubi setelah digoreng. Penggunaan filem CZ menjadikan
    permukaan filem licin dan wujud tanpa sebarang retakan. Filem MC pula memberi lapisan permukaan yang tidak rata
    tetapi menyaluti permukaan sampel dengan sekata. Tambahan pula, ubi bersalut MC menunjukkan peratusan lemak paling
    sedikit (13.6%) selain kandungan kelembapan yang paling tinggi (17.5%) berbanding sampel lain. Secara keseluruhan,
    MC merupakan filem yang terbaik untuk mengekalkan kelembapan bahan goreng dan mengurangkan penyerapan lemak.
  6. Adil Hakam, M. Suzeren M. Jamil, Rizafizah Othaman, Azwan Mat Lazim, Abdul Rahman I, Mohamad Amin M
    Sains Malaysiana, 2015;44:827-834.
    In this study, Bacterial cellulose (BC) grafted with Acrylic acid (AA) was prepared using Co60 γ-rays source (30 KGy).
    Although many samples were prepared, BC: AA with ratio of 1:1 labelled as A1 and 2:1 labelled as A2 gave the most
    significant results. Hence these particular ratios have been selected and further investigated. AA was proven grafted onto
    BC by using ATR-FTIR due to the absent of C-O stretching (1040 cm-1) in both hydrogels. The SEM image of both hydrogels
    samples showed highly porosity networks structure have been produced. The physical properties of the hydrogels such
    as equilibrium water content (%) and swelling ratio (%) in different pH buffer solution were measured. It was found
    that the equilibrium water content (%) of A1 was 93.10% while A2 was 74.83%, respectively. The results indicated that
    the equilibrium water content (%) increased by gaining the AA concentration. At pH10, the A2 swelling ratio (%) was
    two folded with 3350% in comparison with the A1. For the removal of methylene blue (MB) from aqueous solution, the
    results from the UV-VIS spectroscopy demonstrated that the A2 sample hydrogel was also an effective absorbent material
  7. Nur Asmadayana Hasim, Mohd Izhar Ariff Mohd Kashim, Mohammad Zaini Yahaya, Muhammad Adib Samsudin, Rozida Khalid, Rizafizah Othaman
    Sains Malaysiana, 2016;45:1879-1885.
    Setiap kejadian semula jadi merupakan rahmat dan memberi kemaslahatan kepada manusia termasuklah pendarahan haid dalam kalangan wanita. Haid merupakan suatu proses yang unik dan terancang yang melibatkan tiga fasa utama iaitu fasa haid, fasa folikel dan fasa luteal. Objektif penyelidikan ini ialah untuk mengkaji dan menghubungkaitkan kebaikan haid daripada perspektif sains dan maqasid syariah. Kajian ini dijalankan dengan menggunakan ulasan literatur secara deskriptif. Kajian mendapati bahawa perubahan hormon, warna darah dan faktor fiziokimia lain memberi kesan terhadap kenormalan kitaran haid. Darah haid juga dikenal pasti mempunyai agen antimikrob terutamanya terhadap bakteria E. coli dan bakteria Gram-negatif lain. Hal ini bertepatan dengan maqasid syariah memelihara jiwa kerana haid mampu juga memelihara kesihatan wanita. Selain itu, kajian lepas menemukan bahawa darah haid terdiri daripada sel stem yang boleh digunakan dalam aktiviti klinikal pada masa akan datang. Maqasid syariah melindungi keturunan juga dapat dilihat dengan kehadiran haid yang sering digunakan bagi menjangkakan waktu subur bagi merancang kehamilan. Hikmah Islam melarang mendekatkan diri (bersetubuh) dengan wanita yang sedang haid adalah satu rahmat yang besar, kerana wanita yang sedang haid biasanya mempunyai kelaziman gejala prahaid (PMS) yang melibatkan isu kesihatan. Oleh itu, haid daripada perspektif sains adalah bertepatan dengan maqasid syariah.
  8. Ain Athirah Zainuddin, Rizafizah Othaman, Wan Syaidatul Aqma Wan Mohd Noor, Farah Hannan Anuar, Takeno Akiyoshi, Takahashi Shinya
    Sains Malaysiana, 2018;47:1117-1122.
    Poly(ethylene glycol)-polydimethylsiloxane (PEG-PDMS) crosslinked copolymers with mol ratios PEG:PDMS:Glycerol
    of 5:3:2, 6:2:2 and 7:1:2 have been prepared and characterized. The synthesis of the copolymers was carried out
    by the reaction between hydroxyl groups of PEG, PDMS and glycerol with isocyanate groups of 1,6-hexamethyelene
    diisocyanate (HMDI). In the reaction, glycerol was acted as the cross linker. The copolymers were then characterized
    by FTIR spectroscopy. The thermal behaviour was investigated by DSC and TGA. Based on FTIR results, the crosslinked
    structure of the copolymers was confirmed by the presence of absorption peak at 3350 and 1710 cm-1 which indicated
    the (-N-H) stretching and carbonyl (-C=O) correspond to urethane links. This showed that the hydroxyl groups of PEG,
    PDMS and glycerol have reacted to isocyanate groups of HMDI. The copolymers showed melting temperature (Tm) of PEG
    segments from 22°C to 27°C and glass transition temperature (Tg
    ) from -11°C to -6°C. Meanwhile, the PDMS segment
    showed values from -53°C to -56°C for Tm, and Tg
    from -118°C to -122°C. Data obtained from the thermal analysis
    indicate that thermal stability increases with increasing PDMS mol ratio.
  9. Poh Lee Loh, Noor Azlina Abdul Ghani, Nabilah Suhaili, Zetty Shafiqa Othman, Muhammad Rahimi Yusop, Rizafizah Othaman, et al.
    Sains Malaysiana, 2018;47:1123-1129.
    Glycerol, the main by-product in biodiesel manufacturing, is a useful and environment-friendly solvent for many organic
    and inorganic substrates. This study investigates the effects of soaking using glycerol, silicone oil, dimethyl sulfoxide
    (DMSO) and Organosolv (1:1 water: ethanol) on energy consumption in the process of grinding kempas wood and on
    the particle size of ground kempas. Kempas wood chips were soaked in various solvents at 90°C for 1 h. The structural
    characterisation of untreated and treated kempas was analysed using CHNS, ATR-FTIR and XRD. Meanwhile, the grinding
    energy was calculated based on power per unit time while particle size was analysed using nested column sieves. Glycerol
    has high stability, good compatibility with other chemicals and is environmentally friendly. Glycerol-soaked kempas
    consumed less energy which led to energy saving of up to 0.015 W h and exhibited the smallest average particle size
    (263 µm) close to that of untreated kempas due to glycerol lubricating properties. Therefore, glycerol can be used as
    an alternative to conventional solvents in reducing the grinding energy consumption and particle size of lignocellulosic
    biomass.
  10. Nur Asmadayana Hasim, Muhammad Adib Samsudin, Mohammad Zaini Yahaya, Latifah Amin, Rizafizah Othaman, Rozida Khalid, et al.
    Sains Malaysiana, 2018;47:1227-1234.
    Islam merupakan satu agama yang menitikberatkan kesihatan manusia termasuklah sistem pencernaan manusia. Najis
    (tinja) manusia yang dibincangkan dalam kajian ini merupakan hasil buangan manusia yang menjadi salah satu kaedah
    untuk melihat sudut kesihatan manusia. Objektif penyelidikan ini ialah untuk mengkaji fizikokimia dan ciri-ciri najis
    serta kegunaannya daripada perspektif sains dan sudut pandangan Islam terutamanya mengenai diet yang diamalkan
    oleh Rasulullah SAW. Kajian ini dijalankan dengan menggunakan ulasan literatur secara deskriptif. Kajian mendapati
    bahawa sistem pencernaan merupakan satu sistem yang rumit. Tinja terdiri daripada 75% air dan 25% bahan pepejal
    serta ciri-ciri tinja seperti bentuk, warna dan bau memberi kesan kepada kesihatan manusia. Daripada sudut Islam
    warna, bau dan rasa tinja merupakan perkara asas yang dititikberatkan semasa proses pembersihan najis terutamanya
    bagi memulakan sesuatu ibadah. Selain itu, diet, senaman, umur dan jantina merupakan faktor-faktor yang membezakan
    jenis tinja bagi setiap individu. Malah, kajian ini juga merungkai beberapa alternatif yang kini diguna pakai bagi
    mengurus najis-najis manusia dalam menjamin kesihatan dan pemeliharaan alam sekitar. Kajian ini kemudiannya
    mengupas diet makanan-makanan sunnah yang terdapat di dalam Al-Quran dan hadis yang terbukti kaya dengan serat
    dan sihat untuk manusia terutamanya bagi sistem pencernaan manusia. Oleh itu, najis (tinja) manusia daripada sudut
    sains mampu menggambarkan kesihatan seseorang dan amalan diet makanan-makanan sunnah sangat baik dalam
    memelihara sistem pencernaan manusia.
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