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"The mathematical model was selected and the empirical equations were formulated from laboratory measurement by disturbed soil that was applied in undisturbed soil or field so required a correction factor. The correction factor could be expressed as a value of channeling fraction. The channeling process will affect to the average velocity of soil solution flow in soil. The average velocity of soil solution flows in soil controlled the fate of pesticide in undisturbed soil. The soil solution flows at undisturbed soil were expressed as two difference velocity values. The first part has equal velocity as its superficial velocity. The second part, because of chanelling, it was arbitrarily determined to be 10 times of the superficial velocity, and therefore, the superficial velocity of soil solution in the undisturbed soil must be corrected by the channeling fraction. The objective of the verification experiment was to identify a correction factor that could be expressed as channeling fraction in the equation as follows:V undisturbed soil = (1-channeling fraction) V Superficial + chanelling fraction (10 x v superficial)The verification was carried out at undisturbed soil obtained from three locations. The undisturbed soil in PVC pipe was saturated with water. After a saturated condition is reached, the flow direction of water was turned from top to bottom. The water continuously flows. After the steady state condition, water flow were substituted with the flow of fenitrothion solution, at the time was regarded as an initial condition (t=0). At the certain time the soil solutions at the outlet were taken to be determined the concentration of fenitrothion by HPLC. Based on the selected mathematical model and theempiricial equitations, the concentration of pesticide in soil solution as a position and time function can be calculated. The correction factor or the channeling fraction could be evaluated by comparing the fenitrothion concentration as a time function, from laboratory experiment data and from mathematical simulation result. The obtained channeling fraction values are 0.03, 0.05, and 0.1 for the clay loam-clay, the sandy loam-sand, and the loam-sandy loam textures, respectively."

"ABSTRAKAdanya ketidaklinearan pada reaktor alir tangki berpengaduk mampu menyebabkan gangguan ketika proses sedang berjalan. Gangguan tersebut menyebabkan turunnya kualitas produk, sehingga diperlukan penanganan terhadap gangguan. Skripsi ini membahas penggunaan Representative Model Predictive Control (RMPC) dalam memilih beberapa model predictive control (MPC) lokal yang kemudian dikombinasikan untuk membuat Multi Model Predictive Control (MMPC), dan digunakan untuk menangani gangguan pada proses. Penelitian ini menggunakan model reaktor Bequette dan disimulasikan menggunakan perangkat lunak MATLAB. Variabel bebasnya adalah konsentrasi feed sedangkan variabel kontrolnya adalah konsentrasi produk dan suhu reaktor. Hasil dari penelitian menunjukkan IAE MMPC lebih kecil dari IAE PI.

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ABSTRACTExisting nonlinearity in continuous stirred tank reactor can cause disturbances when the process is running. Those disturbances cause a decline in product quality, so that disturbances rejection control is needed. The use of Representative Model Predictive Control (RMPC) in selecting some of the local Model Predictive Control (MPC) and then combined to make Multi Model Predictive Control (MMPC) are discussed and explained. MMPC, a Bequette reactor model, and MATLAB software were used and applied to handle disturbances and simulate. Manipulated variable is feed concentration while the controlled variables are product concentration and reactor temperature. The results of this study show that IAE value of MMPC is smaller than IAE value of PI."

"Tanaman melinjo (Gnetum gnemon L.) memiliki banyak manfaat. Salah satunya pada buah melinjo yang selain bisa sebagai bahan makanan, juga dapat sebagai antioksidan. Pada penelitian ini dilakukan identifikasi kandungan senyawa kimia di dalam ekstrak kasar etanol dari kulit luar, kulit keras dan daging buah pada melinjo. Ketiga bagian buah melinjo yang kering dimaserasi dengan larutan etanol 50%. Filtrat yang didapat dipekatkan, sehingga didapat ekstrak kasar yang berwarna kuning-coklat terang pada daging buah, kuning-coklat gelap pada kulit keras dan kuning-coklat agak gelap pada kulit luar. Hasilnya kemudian di uji bercak KLT untuk mengetahui jumlah komponen senyawa yang ada dengan perbandingan efluen etil asetat : n-heksan, kloroform : metanol dan metanol : etil asetat. Setelah itu, dilakukan pengidentifikasian senyawa dengan menggunakan spektrometer GC-MS. Dari informasi yang didapat, ternyata pemisahan dengan GC-MS ditemukannya senyawa metil-β-D-galaktopiranosida pada sampel daging buah (73,58%, 87) dan kulit keras (84,22%, 87) serta senyawa metil-α-D- glukopiranosida pada sampel kulit luar buah (20,39%, 80). Selain itu juga teridentifikasi adanya senyawa 2,3-dihidro-3,5-dihidroksi-6-metil-4H-piran-4-on pada daging buah (1,87% , 90) dan kulit luar (4,10% , 91).

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Melinjo (Gnetum gnemon L.) has many benefits. One of them can be used a food ingredient and also as a antioxidant. In this research, we identified of chemical compounds in the crude extract ethanol from the outer shell, hard shell and pulp of fruit on melinjo. The three parts are dried fruits macerated melinjo with 50% ethanol solution. The filtrate obtained was concentrated, so to get a crude extract of a yellow-brown light on the pulp of fruit, dark yellow-brown on hard shell and yellow-brown hard bit dark on the outer shell. The result is then tested to determine the amount of spotting KLT components of existing compounds by comparison solvent system, ethyl acetate: n-hexane, chloroform: methanol and methanol: ethyl acetate. After that, the identification of compounds by using GC- MS spectrometer. From the information obtained, we found compound methyl-β- D-galaktopiranosida on pulp of fruit (73.58%, 87) and the hard shell (84.22%, 87) and methyl-α-D –glukopiranosida on the outer shell of the fruit sample (20.39%, 80). It also identified the compound 2,3-dihydro-3 ,5-dihydroxy-6-methyl-4H- pyran-4-on the pulp of the fruit (1.87%, 90) and the outer shell (4.10%, 91 )."

"Penelitian ini membandingkan karakteristik pengabutan dan pembakaran dari campuran minyak nabati dan bahan bakar minyak pada setiap rasio pencampuran nya. Semburan nyala api pada pembakaran yang beroperasi pada tekanan 0,2 hingga 1,2 bar diamati secara optis. Bahan bakar nabati (BBN) memiliki kekentalan (viskositas) yang besar sehingga menjadi kendala dalam proses pembakaran. Karena itu untuk menurunkan viskositas nya perlu dicampur dengan bahan bakar minyak (BBM). Pembakaran yang baik memerlukan proses pengabutan yang baik. Pada penelitian ini proses pengabutan nya menggunakan nosel jet. Pengukuran kualitas pengabutan dan pembakaran dilakukan dengan metode fotografi dan perangkat lunak pemrosesan citra. Hasilnya menunjukkan bahwa rasio campuran BBN dan BBM yang terbaik adalah 40% : 60% untuk semua jenis campuran (minyak jelantah dan solar, minyak curah dan solar, minyak nyamplung dan solar serta minyak curah dan minyak tanah) dan tekanan operasi terbaik adalah 1,2 bar. Pada kondisi tersebut, campuran minyak curah dan minyak solar memiliki rerata suhu nyala yang paling tinggi (391,6oF) dan distribusi partikel aerosol terkecil yang paling tinggi (73%) meskipun masih di bawah BBM murni (100%).

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The spray atomization and combustion characteristic of vegetable oil and fosil fuel are compared to those ratio of mixtures on this paper. The spray flame was contained in an optically accessible combustor which operated at 0,2 - 1,2 bar of air pressure. Vegetable Fuel (VF) contains high viscosity that has been a, constraint in the combustion process; it needs to be mixed with Fosil Fuel (FF) in order to decrease the VF viscosity. A fine atomization process is necessary to fix the combustion. Research of atomization process was tested by using nozzle jet. The atomization and combustion quality were investigate by photographic method and image processing software was used to measure the spray droplet size. As a testing result, ratio mixture of 40% : 60% of VF and FF was good ratio mixtures ( used cooking oil diesel oil, cooking oil and diesel oil, nyamplung oil and diesel fuel, cooking oil and kerosene) compared to others ratio which operated at 1,2 bar of air pressure implying flame temperature. The flame temperatur of cooking oil and diesel oil mixture reached (391,6oF) as the highest mean temperature and distribution of aerosol particle reached (73%) although produced lower than fosil fuel (100%)."

"Saat ini masih terdapat beberapa kendala dalam penggunaan bio oil sebagai bahan bakar yaitu rendahnya nilai heating value tingginya tingkat keasaman korosif dan tidak stabil disebabkan tingginya kandungan senyawa oksigenat di dalam bio oil Penelitian ini bertujuan untuk mendapatkan bio oil dengan kadar oksigenat lebih rendah dan aromatik lebih tinggi Dalam penelitian ini digunakan metode fast pyrolysis pada temperatur 550oC dengan empat variasi yaitu produksi bio oil tanpa katalis dan produksi bio oil dari 3 jenis biomassa jerami padi kayu karet dan tandan kosong kelapa sawit dengan katalis Ni ZSM 5 Penggunaan katalis terbukti berpengaruh aktif terhadap proses deoksigenasi dan aromatisasi Secara berurutan kandungan senyawa aromatik paling tinggi didapat dari proses pirolisis katalitik biomassa kayu karet 10 25 pirolisis katalitik jerami padi 7 8 pirolisis katalitik TKKS 6 22 dan pada pirolisis non katalitik tidak ditemukan senyawa aromatik Kayu karet merupakan biomassa yang paling banyak mengandung selulosa.

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There are several obstacles that inhibit the use of bio oil as fuel such as low heating value high levels of acidity corrosive and unstable due to high content of oxygenated compounds in the bio oil This study aims to obtain bio oil with less oxygenated compounds and higher aromatics This study use fast pyrolysis method at 550oC with four variations ie the production of bio oil without catalyst and bio oil production from 3 types of biomass rice straw rubber wood and empty fruit bunches with Ni ZSM 5 catalyst The use of catalyst proved to affect the process of deoxygenation and aromatization Sequentially the high content of aromatic compounds derived from catalytic pyrolysis of rubberwood 10 25 catalytic pyrolysis of rice straw 7 8 catalytic pyrolysis of EFB 6 22 and aromatics were not found in non catalytic pyrolysis Rubber wood is biomass that mostly contain cellulose and hemicellulose as the largest contributor to the content of aromatic hydrocarbons."

"Konsumsi energi proses produksi klor alkali yang tinggi mendorong perlu dilakukannya peningkatan efisiensi proses. Elektrolisis plasma merupakan modifikasi proses elektrolisis yang dapat meningkatkan nilai produksi dan efisiensi energi hingga berkali-kali lipat. Penelitian ini menggunakan larutan kalium klorida sebagai bahan baku elektrolisis untuk memproduksi gas klor sebagai produk utama. Pada penelitian ini, berbagai fenomena terkait pembentukan plasma dijelaskan, seperti intensitas warna, penurunan nilai arus, dan pengaruh ketinggian elektroda. Hasil penelitian menunjukkan efisiensi tertinggi didapat pada konsentrasi tertinggi dan tegangan 400 V dengan peningkatan efisiensi terhadap proses elektrolisis mencapai 13 kali lebih besar.

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High energy consumption of chlor-alkali process encourage the importance of the efficiency improvement. Plasma electrolysis is a modification of electrolysis method that can increase productiviy and efficiency level up to several times. This study uses a solution of potassium chloride as a raw material to produce chlorine gas as the main product.

In this study, various phenomena related to plasma formation are described, such as color intensity, decreasing of the current value, and the influence of the electrode height. The results showed the highest efficiency obtained at the highest concentration and 400 volt with an increase in the efficiency of the electrolysis process at 13 times greater."