1,095 research outputs found

    Utilization of Palm Oil Mill Effluent for Chlorella vulgaris Cultivation Medium under Mixotrophic Condition as Feedstock of Biofuel

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    Indonesia is largest palm oil producer in the world. Increasing of palm oil influence palm oil mill effluent (POME) production. Several researcher reported that POME is a potential medium for microalgae to grow. Microalgae cultivated in mixotrophic condition has received attention as according to higher biomass and lipid productivity to provide biofuel feedstock. The aim of this research is to study growth of Chlorella vulgaris cultured in POME medium using different organic carbon source under mixotrophic condition. Carbon source (glucose, glycerol, and acetic acid) was added in 0-1.2gr/l concentration in 40% and 100% POME. Biomass was harvested using autoflocculation method, and dry biomass was extracted using ultrasound method to obtain lipid content. Our result revealed that C. vulgaris could grow on mixotrophic condition in POME medium and produce higher biomass and lipid content rather than autotrophic condition. Concentration of organic source also influenced in growth rate and biomass production. This provides a promising process to utilize POME and produce biomass as feedstock of biofuel from microalgae. Keywords: biofuel feedstock; Chlorella vulgaris; Mixotrophic cultivation; POM

    Enhancement of Biomass Production from Spirulina sp Cultivated in POME Medium

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    Indonesia is the largest producer coconut palm oil in the world. As increasing in production, the palm oil mill efluent are also produced in about 66% by FFB (Fresh Fruit Bunch). Palm oil mill effluent is usually processed by a traditional aerobic open lagoon or by anaerobic digestion. POMED (palm oil mill effluent digested) has a high nutrient content and it can be used as medium for microalgae cultivation. Spirulina sp is a kind of cyanobacteria contains high protein and a potential product for animal feed. This research purpose is to find optimum saving synthetic nutrient of Spirulina sp cultivated in POMED and to find optimum POMED concentration used for algae cultivation. Research was done in two steps. First step, Spirulina sp was cultivated in 20% POMED concentration with different saving nutrient (0%, 20%, 50%, 70%, and 90%). At second step, Spirulina sp was cultivated in different POMED concentration (10%, 20%, 30%, 40%, 50%, 60% v/v) for 16 days. At first 8 days, nutrient was added to medium. At second 8 days, the nutrient was not added to medium.. Optical density was monitored every day using spectrophotometer with wave length 680nm. At the end of cultivation, medium was filtered to obtain wet biomass (10% Total suspended solid). Spirulina sp can grow well in 20% POMED, save 50% from synthetic nutrient, and produced 5.93gr/l wet biomass for 9 days. Research was continued without adding nutrient and produced optimum biomass 9.8gr/l in 40% POMED for 13 days. Keywords: optimum biomassa, POMED, saving synthetic nutrient, Spirulina s

    Study On Production Process of Biodiesel from Rubber Seed (Hevea Brasiliensis) by In Situ Transesterification Method with Alkaline Catalyzed

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    Biodiesel is methyl or ethyl fatty acids generated from vegetable oils (edible and non edible) or animal fats. Production of biodiesel from rubber seeds by in situ alkaline catalyzed method from non edible raw materials with a major goal for alternative fuels was studied. The objective of this research is to investigate the influence of reaction time, concentration of alkaline catalyst and ratio raw materials : methanol to the production of biodiesel. The first stage was carried out in order to get reaction time based on the density and viscosity of mixture. In this process, KOH 0.5% (w/v) was used as catalyst with the ratio rubber seed to methanol (1:2). Experiments followed by process with catalyst concentration variation in range 0.1-1% (w/v) and ratio rubber seed to methanol in range 1:1.5-1:3. Research method included, the preparation of samples, biodiesel production, biodiesel separation, and biodiesel characterization include density, viscosity, GC analysis, acid value and Iodine number. The results show that operation time for biodiesel production by using in situ method with alkaline catalyzed was 120 minutes and maximum yield of Fatty Acid Methyl Ester (FAME) was obtained at 52.86%. Keywords: Biodiesel, rubber seed, in situ, (trans) esterification, Fatty Acid Methyl Ester (FAME)

    Optimization in Eugenol Production from Clove Oil with Saponification – Neutralization Process by using Response Surface Methods

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    The objective of this research was to obtain optimum condition in eugenol production from clove oil with response surface methods. Clove oil was founded from essential oil cluster in Batang district Central Java. The eugenol was produced with saponification and neutralization process. Eugenol was obtained with vacuum distillation. Eugenol concentration was analyzed with gas chromatography. In this research, the variable was studied are temperature and ratio of sodium hydroxide to clove oil and yield of eugenol as response variable. So the results was obtain in minimum condition with yield of eugenol 39.17% at X 1 = -0,0109 and X 2 = 0.3095 with determinant coefficient 0.764

    VALORISASI MIKROALGA UNTUK PENGOLAHAN LIMBAH CAIR KELAPA SAWIT DAN SEBAGAI SUMBER ENERGI DAN PANGAN ALTERNATIF

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    Limbah Cair Kelapa Sawit (Palm Oil Mill Effluent-POME) merupakan limbah hasil pemrosesan buah kelapa sawit mentah (Fresh Fruit Bunch) menjadi Crude Palm Oil (CPO). Dari 1 ton FFB akan dihasilkan 0.2 ton CPO dan 0.6 ton POME serta sisanya limbah padat. Dengan kandungan COD 50.000 ppm dan BOD 25.000 ppm, maka limbah POME ini merupakan limbah berbaya yang memerlukan penanganan sebelum dibuang ke lingkungan. Selain kandunagn COD dan BOD yang tinggi, limbah POME masih mengandung nutrisi tinggi yaitu Nitrogen, Phosphor dan Kalium yang dapat digunakan sebagai nutrisi untuk tanaman termasuk mikroalga. Penanganan yang selama ini dilakukan adalah dengan menggunakan kolam facultative anaerob di mana limbah POME diaerasi dalam sehingga kandungan COD akan turun. Namun demikian, metode ini masih menjadi persoalan saat aerasi gas CH4 dan CO2 terlepas ke udara sehingga POME menjadi sumber pencemaran gas rumah kaca. Diperkirakan 1 ton POME dapat menghasilkan 12.36 kg gas CH4 dan 6.4 kg gas CO2. Sehingga diperlukan suatu metode pengolahan dan pemanfaatan limbah cair kalapa sawit ini untuk menurunkan kandungan COD sekaligus mengurangi emisi gas rumah kaca yang dihasilkan. Pada karya unggulan ini, akan ditampilkan metode pengolahan limbah POME dengan memanfaatkan mikroalga. Limbah cair kelapa sawit dengan kandungan COD tinggi difermentasi secara anaerob dalam biodigester untuk menghasilkan biogas dimana 1 ton POME akan dihasilkan 28 m3 biogas. Selanjutnya sisa limbah yang telah difermentasi digunakan sebagai media tumbuh mikroalga karena masih mengandung nutrisi (N,P dan K) tinggi. Untuk tumbuh, mikroalga dalam open pond dialiri biogas sebagai sumber carbon untuk fotosintesis. Mikroalga setelah 1-2 minggu dapat meghasilkan biomasa dengan kandungan protein, lipid maupun karbohidrat tergantung pada jenis mikroalganya. Biomasa ini dapat dimanfaatkan sebagai pakan ternak, sedangkan biogas dapat dimanfaatkan sebagai sumber energy listrik maupun memasak. Kata Kunci : Mikroalga, Spirulina, Biorefiney, Energi, Paka

    The Electrical Properties of Al, ga1-Xn Thin Films Deposited on Si(111) Substrate by Chemical Solution Deposition Method

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    AlxGa1-xN thin films with the GaN buffer layer was deposited on Si(111) substrate by chemical solution deposition (CSD) method. The objective of this research was to evaluate the electrical properties of AlxGa1-xN with variation of Al mole fraction. The source for Ga and Al were gallium oxide (Ga2O3) and aluminum oxide (Al2O3), respectively as group III precursors and radical nitrogen resulted by high temperature decomposition of nitrogen gas. The mole fractions of solutions were varied between 15 to 35%. The formed white crystal was dissolved in ethylene diamine to form gel with molarities of 3-6 M. Therefore, the gel was superimposed on substrates Si with spin-coater at speed of 1100 rpm. The formed layer was then sintered at temperature of 900 C o such that it decomposed at N2 gas environment to form AlxGa1-xN. The composition of films was measured by energy dispersive of x-ray (EDX) and the measured Al concentrations were in the range of 9.52% to 24.19%. The electrical transport of the films was measured by means of Hall effect measurement at room temperature. The Hall mobility decreases with the increase of aluminum (Al) concentration and decrease carbon concentration. The resistivity increases with the increase of Al concentration. From the Hall effects measurement the AlxGa1-xN films have n-type conduction originated from nitrogen vacancy

    Catatan taksonomi polychaeta di pantai intertidal berbatu Gunung Kidul, Yogyakarta

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    Tiga puluh spesies polychaeta telah dilaporkan dari pantai intertidal berbatu “Gunung Kidulâ€, Yogyakarta. Semua spesimen disimpan di Pusat Penelitian Oseanografi (P2O-LIPI), Jakarta. Kebanyakan polychaeta tersebut tersebar luas di perairan Indo-West Pacific. Sembilan belas dari seluruh spesies yang teridentifikasi terindikasi sebagai temuan pertama di perairan Indonesia, tetapi temuan tersebut perlu diverifikas

    “Denmark As A Prison of Life” In Shakespeare’s Hamlet (A Semiotic Approach In Literature)

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    AbstractHamlet is one of the well-known Shakespeare’s drama highlighting betrayal, murder, and revenge. This paper discusses Shakespeare’s Hamlet by studying signs in the text with a semiotic approach in literature. “Denmark is prison” is chosen to be the primary signifier in Shakespeare’s Hamlet that can represent all the main characters’ feeling and perspective in the text such as Hamlet, Claudius, Getrude, Hamlet’s ghostly father, Polonius, Ophelia, Laertes, Horatio, Fortinbras, Rosencrantz, and Guildenstern. They feel Denmark is a prison for their heart. Prison is a symbol of an unpleasant place where the dwellers do not feel happy since they cannot live freely. The characters’ own feeling leads them to live in Denmark unhappily. The story climax is that all of the main characters at the end of the story suffer or die tragically. Key words: Hamlet, signifier, prison, betrayal, murder

    THE FREUDIAN PSYCHOLOGICAL PHENOMENA AND COMPLEXITY IN DAPHNE DU MAURIER’S “REBECCA†(A PSYCHOLOGICAL STUDY OF LITERATURE)

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    The relationship between literature and psychology commonly derives from psychological dimension in literary works and the application of psychology theory in interpreting literary texts. This essay discusses a psychological study in Daphne Du Maurier’s Rebecca based on Sigmund Freud’s psychoanalysis theory. Rebecca is a very psychological novel, since a lot of psychological phenomena emerges from the beginning to the end of the novel. Psychological phenomena found in the novel among other things are dream analysis, Narcissist complex, Cinderella complex, Electra complex, impulsive id, ego, and super ego, cathexis, as well as various types of ego defense mechanism. Each character within the novel such as Rebecca, Maxim de Winter, Maxim’s second wife, and Mrs. Danvers, have his or her psychological characteristics, reaction, and problem. Dream in the beginning and the burning Manderley house at the end of the story are symbol of the ultimate psychological phenomena in the novel Rebecca

    INTEGRASI PENDIDIKAN KARAKTER DI SMP PONDOK PESANTREN MODERN NURUL IKHLAS KABUPATEN TANAH DATAR SUMATERA BARAT

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    The study of integration of character education in Junior Secondary School Nurul Ikhlas Tanah Datar, West Sumatra is a joint research with the approach of a combination of quantitative and qualitative, aims to understand the efforts undertaken by the leadership of the boarding school and the principal to integrate character education or character values that are universal to the school management processes. Among the character values uniquely invested in modern boarding school Nurul Ikhlas are: Deepening Religious Sciences, the mole, Compliance, Modeling, Piety, Independence, Discipline, Simplicity, Tolerance, feel enough, Humility, Fortitude, Solidarity, Sincerity, Cling to religion, Society, Cleanliness.  The seventeenth character is jointly invested well for students to learn at school and when students receive education from boarding schools, to teachers and other education personnel. The uniqueness of Junior Secondary Boarding School Nurul Ikhlas in integrating character education into the educational process so as to produce quality graduates, an attraction for parents and prospective students to study at the boarding school.  This concern which contribute optimally to support both leaders and the head of the boarding school so that the educational process can be managed optimally.  This suggests the process of character education is not only optimal in boarding schools, but also in regular schools, both public and private that currently require it
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