Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Search Results: 1 - 10 of 1303 matches for " Ramli Mat "
All listed articles are free for downloading (OA Articles)
Page 1 /1303
Display every page Item
Hydrolysis of Virgin Coconut Oil Using Immobilized Lipase in a Batch Reactor
Lee Suan Chua,Meisam Alitabarimansor,Chew Tin Lee,Ramli Mat
Enzyme Research , 2012, DOI: 10.1155/2012/542589
Abstract: Hydrolysis of virgin coconut oil (VCO) had been carried out by using an immobilised lipase from Mucor miehei (Lipozyme) in a water-jacketed batch reactor. The kinetic of the hydrolysis was investigated by varying the parameters such as VCO concentration, enzyme loading, water content, and reaction temperature. It was found that VCO exhibited substrate inhibition at the concentration more than 40% (v/v). Lipozyme also achieved the highest production of free fatty acids, 4.56?mM at 1% (w/v) of enzyme loading. The optimum water content for VCO hydrolysis was 7% (v/v). A relatively high content of water was required because water was one of the reactants in the hydrolysis. The progress curve and the temperature profile of the enzymatic hydrolysis also showed that Lipozyme could be used for free fatty acid production at the temperature up to 50°C. However, the highest initial reaction rate and the highest yield of free fatty acid production were at 45 and 40°C, respectively. A 100 hours of initial reaction time has to be compensated in order to obtain the highest yield of free fatty acid production at 40°C. 1. Introduction Coconut oil, which is derived from the seeds of coconut palm, Cocos nucifera, is traditionally processed from the meat of the fruit, called copra. Copra is the dried kernel that produced by smoke drying, sun drying, or a combination of both methods. Therefore, it is usually colorless to pale brownish yellow. Recently, the most welcomed product from coconut is virgin coconut oil (VCO), particularly from the tropical countries. The concept of producing VCO is actually triggered by the well-known virgin olive oil that produced from Mediterranean Basin. The high demand for the virgin oils is definitely due to the preservation of oil composition, including the minor components such as provitamin A, vitamin E, phytosterols, and polyphenols, without aflatoxin contamination and oxidative rancidity from drastic processing and handling approach. These minor components are believed to have the nutritional benefits. By definition, VCO is defined as the oil obtained from the fresh, mature kernel of coconuts by mechanical or natural means without the use of heat, chemical refining, bleaching, and odorizing which does not lead to the alteration of the natural content of the oil [1]. It should also have the moisture content less than 0.1%. Because of the beneficial effects on human health [2, 3] and high saturation degree [1] as well as high oxidative stability of VCO [4], the oil is the great source of oil material for the production of value-added
Journal of Sustainability Science and Management , 2007,
Abstract: The Direct conversion of methane to liquid hydrocarbons either over metal catalyst or zeolite catalyst is so far not successful in achieving the methane conversion and liquid hydrocarbons selectivity within the economic range. The present research concern is directed towards modifying HZSM-5 zeolite catalyst with the oxidative element to produce an active bi-functional oxidative-acid catalyst. This modification method has shown an improvement in the catalytic activity and product selectivity. The HZSM-5 zeolite catalyst was modified by an acidic ion exchange method to produce the Ga-HZSM-5 zeolite catalyst. The effect of different reaction temperatures on the catalytic activity of Ga-HZSM-5 catalyst was studied. Direct oxidation of mixture of methane and oxygen over the catalyst was carried out in a micro packed bed reactor. The liquid and gas products were analyzed by gas chromatography. The optimum reaction temperature at GHSV of 6000 hr-1 was observed at 800oC in order to obtain the optimum output.
In Situ Biodiesel Production from Residual Oil Recovered from Spent Bleaching Earth
Ramli Mat,Ow Shin Ling,Anwar Johari,Mahadhir Mohammed
Bulletin of Chemical Reaction Engineering & Catalysis , 2011, DOI: 10.9767/bcrec.6.1.678.53-57
Abstract: Currently, semi-refined and refined vegetable oils are used as a feedstock in biodiesel production. However, due to competition with conventional fossil fuel, economic reasons, shortage supply of food and its social impact on the global scale has somewhat slowed the development of biodiesel industry. Studies have been conducted to recover oil from mill palm oil operation especially from the spent bleaching earth. Hence, the study was to investigate the potential recovery of oil from spent bleaching earth to be used as a feedstock for biodiesel production. The effect of different types of catalysts (sodium hydroxide alkali and sulfuric acid catalysts) on biodiesel yield was studied. In addition, the effect of volume addition of methanol to the weight of spent bleaching earth on the product yield was also studied. Furthermore, the effect of ratio of hexane to methanol was also carried out to determine its product yield. The studies were carried out in an in-situ biodiesel reactor system and the biodiesel product was analyzed using gas chromatography mass spectrometry. Result shows that the use of alkali catalyst produced the highest yield of biodiesel and the most optimum biodiesel yield was obtained when the methanol to spent bleaching earth ratio was 3.2:1 (gram of methanol: gram of SBE) and hexane to methanol ratio of 0.6:1 (volume of hexane: volume of methanol). 2011 BCREC UNDIP. All rights reserved (Received: 19th December 2010, Revised: 10th May 2011; Accepted: 18th May 2011) [How to Cite: R. Mat, O.S. Ling, A. Johari, M. Mohamed. (2011). In Situ Biodiesel Production from Residual Oil Recovered from Spent Bleaching Earth. Bulletin of Chemical Reaction Engineering & Catalysis, 6(1): 53-57. doi:10.9767/bcrec.6.1.678.53-57] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.1.678.53-57 ] | View in
Solid Catalysts and theirs Application in Biodiesel Production
Ramli Mat,Rubyatul Adawiyah Samsudin,Mahadhir Mohamed,Anwar Johari
Bulletin of Chemical Reaction Engineering & Catalysis , 2012, DOI: 10.9767/bcrec.7.2.3047.142-149
Abstract: The reduction of oil resources and increasing petroleum price has led to the search for alternative fuel from renewable resources such as biodiesel. Currently biodiesel is produced from vegetable oil using liquid catalysts. Replacement of liquid catalysts with solid catalysts would greatly solve the problems associated with expensive separation methods and corrosion problems, yielding to a cleaner product and greatly decreasing the cost of biodiesel production. In this paper, the development of solid catalysts and its catalytic activity are reviewed. Solid catalysts are able to perform trans-esterification and esterification reactions simultaneously and able to convert low quality oils with high amount of Free Fatty Acids. The parameters that effect the production of biodiesel are discussed in this paper. Copyright 2012 by BCREC UNDIP. All rights reserved Received: 6th April 2012, Revised: 24th October 2012, Accepted: 24th October 2012 [How to Cite: R. Mat, R.A. Samsudin, M. Mohamed, A. Johari, (2012). Solid Catalysts and Their Application in Biodiesel Production. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2): 142-149. doi:10.9767/bcrec.7.2.3047.142-149] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.3047.142-149 ] | View in
Determination of the Probability Plotting Position for Type I Extreme Value Distribution
Ahmad Shukri Yahaya,Norlida Md. Nor,Nor Rohashikin Mat Jali,Nor Azam Ramli
Journal of Applied Sciences , 2012,
Abstract: In this study the emphasis is placed on choosing the best plotting position used for the estimation of the parameters of the Gumbel distribution. The Type I extreme value distribution that is also known as Gumbel distribution has been used frequently to predict return periods in many engineering studies. The location parameter (μ) and scale parameter (σ) of the Gumbel distribution was estimated using the regression method. Simulation was used to obtain random variables of twenty Gumbel distributions with different location and scale parameters. The number of sample sizes chosen is 10, 20, 50, 60, 80 and 100. The sample sizes was divided into three different criteria namely small sample sizes for n = 10 and n = 20; medium sample sizes for n = 50 and n = 60 and large sample sizes for n = 80 and n = 100. This simulation study was replicated ten times. Seventeen plotting position formulae were chosen for this study namely Adamowski, Beard, Blom, Chegodayev, Cunnane, Gringorten, Hazen, Hirsch, IEC56, Landwehr, Laplace, Mc Clung, Tukey, Filliben estimator, Weibull, Gumbel and Anon. These plotting positions were used to estimate the Cumulative Distribution Function (CDF) of Gumbel Distribution. Performance measures comprising of two error measures and two accuracy measures were used to determine the best probability plotting position. It was found that different plotting positions perform well for different sample sizes. The best plotting method for small sample size is Landwehr and Hazen, for medium sample size the most suitable method is Landwehr and for large sample size the best method is the Blom method.
PCR assembly of synthetic human erythropoietin gene
Bustami,Yazmin; Yahya,Ahmad Ramli Mohd; Muhammad,Tengku Sifzizul Tengku; Shu-Chien,Alexander Chong; Abdullah,Amirul Al-Ashraf; Noor,Mohd Azizan Mohd; Arip,Yahya Mat;
Electronic Journal of Biotechnology , 2009,
Abstract: human erythropoietin (huepo) is a glycoprotein with important physiological functions, such as erythropoiesis, angiogenesis, and wound healing. a therapeutic protein, huepo is commonly used to treat patients suffering from renal and non-renal anemia. recombinant human erythropoietin (rhuepo) and endogenous huepo are similar with respect to their biological and chemical properties. in this study, we describe the construction of synthetic huepo gene to produce rhuepo. the synthetic huepo gene was constructed by overlapping oligonucleotides assembly and amplified by polymerase chain reaction (pcr). twenty oligonucleotide sets, covering the huepo gene sequence and two newly introduced restriction enzyme sites, were pulled together and amplified using pfu dna polymerase to produce the expected dna products with sizes of ~500bp and ~600bp. the pcr products were ligated into pgem-t plasmid vector to facilitate dna sequencing process of the constructed huepo gene and downstream cloning manipulation. dna sequence analysis showed correctly assembled oligonucleotide sets, representing the huepo gene sequence albeit with minor base mutations. hence, oligonucleotides assembly and pcr amplification provide a convenient and speedy method for the synthesis of huepo gene without depending on mrna isolation and reverse transcription or the need to have a genomic library.
On the maximal temporal amplitude of down stream running nonlinear water waves
Marwan Ramli
Tamkang Journal of Mathematics , 2010, DOI: 10.5556/j.tkjm.41.2010.51-69
Abstract: This paper concerns with the down-stream propagation of waves over initially still water. Such a study is relevant to generate waves of large amplitude in wave tanks of a hydrodynamic laboratory. Input in the form of a time signal is provided at the wave-maker located at one side of the wave tank; the resulting wave then propagates over initially still water towards the beach at the other side of the tank. Experiments show that nonlinear effects will deform the wave and may lead to large waves with wave heights larger than twice the original input; the deformations may show itself as peaking and splitting. It is of direct scientific interest to understand and quantify the nonlinear distortion; it is also of much practical interest to know at which location in the wave tank, the extreme position, the waves will achieve their maximum amplitude and to know the amplitude amplification factor. To investigate this, a previously introduced concept called Maximal Temporal Amplitude (MTA) is used: at each location the maximum over time of the wave elevation. An explicit expression of the MTA cannot be found in general from the governing equations and generating signal. In this paper we will use a Korteweg - de Vries (KdV) model and third order approximation theory to calculate the approximate extreme positions for two classes of waves. The classes are the wave-groups that originate from initially bi-chromatics and Benjamin-Feir (BF) type of waves, described by superposition of two or three monochromatic waves. We show that for initially bi-chromatics signals, the extreme position does not depend on the phases of the mono-chromatic components. For BF signals, however, the phases of the mono-chromatic components influence the extreme position essentially. The theoretical results are verified for the case of bi-chromatics with numerical as well as experimental results; for BF signals we use an analytical solution called the Soliton on Finite Background (SFB) for comparison.
Ketersampaian Masyarakat Tani Kepada Pelaburan Saham Amanah
Zaimah Ramli
e-BANGI : Journal of Social Sciences and Humanities , 2010,
Abstract: Umum menyedari bahawa melabur dalam saham amanah merupakan suatu langkah bijak dalam usaha meningkatkan pendapatan. Persoalannya, apakah semua lapisan masyarakat di negara ini mempunyai ketersampaian kepada saham amanah tersebut, terutamanya mereka yang tergolong dalam kumpulan berpendapatan rendah. Kajian ini menilai sejauhmana masyarakat desa, iaitu pesawah padi mempunyai ketersampaian terhadap saham amanah yang terdapat di negara ini. Kajian turut mengenalpasti faktor-faktor penggalak dan penghalang yang mempengaruhi ketersampaian mereka. Dapatan kajian mengesahkan bahawa, meskipun kebanyakan golongan petani ini mempunyai pengetahuan umum mengenai saham amanah, tetapi ketersampaian dan penglibatan mereka secara langsung dalam pelaburan tersebut adalah agak terbatas. Tarikan kadar dividen yang tinggi dikenalpasti sebagai faktor penggalak utama mereka menyertai saham amanah. Manakala, dua faktor utama yang menghalang mereka daripada terlibat dalam saham amanah ialah kekurangan pendapatan dan kurangnya pendedahan terhadap pelaburan saham amanah itu sendiri. Secara keseluruhannya, penglibatan pesawah-pesawah padi terbabit dalam saham amanah adalah amat rendah dan terbatas. Fenomena ini cukup jelas apabila kebanyakan mereka kurang berkemampuan untuk mempertahan dan meningkatkan nilai pelaburan mereka.
Ramli Rahim
Dimensi : Journal of Architecture and Built Environment , 2000,
Abstract: Daylight and solar radiation data are important parts of building design process. However, many of the fundamental daylight and solar research studies used by architects and engineers in Indonesia are based upon data taken in other parts of the world. In order to investigate daylight availability data in low latitude/tropic area which are extremely lacking at the present stage, a measurement of daylight and solar radiation was done in Makassar. Cloud ratio is known as a most practical and convenient parameter to specify the real sky conditions. This paper describes the analysis of sky luminance by cloud ratio method which are obtained from the data measured during the period January - December 1995. Abstract in Bahasa Indonesia : Data luminansi dan radiasi surya merupakan bagian yang sangat menentukan dalam proses perancangan bangunan. Dalam kenyataannya, banyak arsitek dan ahli bangunan di Indonesia yang masih menggunakan hasil penelitian yang berdasarkan pada data pengukuran yang diperoleh dari negara lain. Dalam upaya investigasi ketersediaan data luminansi di daerah tropik yang hingga saat ini sangat terbatas, suatu pengukuran data tentang luminansi dan radiasi surya telah dilakukan di Makassar. Rasio awan dikenal sebagai suatu parameter yang cukup praktis dan baik dalam menentukan kondisi langit nyata. Tulisan ini mengungkapkan analisa dari luminanasi langit dengan metode rasio awan yang diperoleh dari pengukuran data selama periode Januari hingga Desember 1995. Kata kunci: luminansi langit, rasio awan, pengukuran data.
Effect of Mechanical Treatment Temperature on Electrical Properties and Crystallite Size of PVDF Film  [PDF]
Ambran Hartono, Suparno Satira, Mitra Djamal, Ramli Ramli, Herman Bahar, Edi Sanjaya
Advances in Materials Physics and Chemistry (AMPC) , 2013, DOI: 10.4236/ampc.2013.31011

Fabrication of PVDF films has been making using Hot Roll Press. Preparation of samples carried out for nine different temperatures. This condition is carried out to see the effect of temperature fabrication on electrical properties and crystallite size of PVDF films. The electrical properties like as surface resistivity are discussion focus in this paper. Surface resistivity properties of PVDF can be improved by mechanical treatment on the varying film thickness and the temperature. To obtain the diffraction pattern of sample characterization is performed using X-Ray Diffraction. Crystallite size of PVDF films calculate from broadening pattern of X-Ray Diffraction. Furthermore, from the diffraction pattern calculated β fraction and crystallite size, for calculation to determine the crystallite size of the sample by using the Scherrer equation. Has been obtained an increase piezoelectric properties of PVDF films that characterized by increasing β fraction. Have been obtained β fraction increased from 25.4% up to 44% for temperatures of 130°C up to 170°C, respectively. Resistivity value has been obtained at temperature 130°C up to 170°C, decreased from 1.23 × 104 Wm up to 0.21 × 104 Wm respectively. From the experimental results and the calculation of crystallite sizes obtained for the samples with temperature 130°C up to 170°C respectively are increased from 7.2 nm up to 20.54 nm. These results indicate that mechanical treatment caused increase β fraction and decrease surface resistivity. Increasing temperatures will also increase the size of the crystallite of the sample. This happens because with the increasing

Page 1 /1303
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.