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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."

"Reaktor plasma dengan konfigurasi umpan 3-lewatan untuk konversi gas CO2 dan CH4 perlu dimodelkan agar dapat merepresentasikan fenomena fisika dan kimia yang terjadi dalam reaktor. Pemodelan ini juga bertujuan mendapatkan kinerja reaktor yang diinginkan agar bisa digunakan sebagai dasar scale-up. Model reaktor disimulasikan dalam tiga dimensi menggunakan COMSOL Multiphysics dengan melihat pengaruh variasi laju alir umpan, temperatur di dalam reaktor, serta rasio mol umpan terhadap konversi dan produk syngas yang dihasilkan. Konversi tertinggi dicapai pada laju alir 4,6 mL/ menit dengan konversi CO2 sebesar 22% dan konversi CH4 sebesar 88,4% dengan rasio syngas yang dihasilkan CO2: CH4 = 1:1,14. Konversi yang dihasilkan tidak mengalami perubahan yang signifikan dengan naik atau turunnya temperatur di dalam reaktor. Dari variasi rasio mol umpan, konsentrasi CO yang dihasilkan meningkat sebanding dengan naiknya konsentrasi umpan CO2. Konsentrasi H2 yang dihasilkan meningkat sebanding dengan naiknya konsentrasi umpan CH4.

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Plasma reactor with 3-pass flow configuration for conversion CO2 and CH4 gas needs to be modeled in order to represent the physical and chemical phenomena that occur in the reactor. This modeling also aims to obtain the desired performance of the reactor to be used as the basis for scale-up. Reactor modeled in three dimensions using COMSOL Multiphysics to see the effect of the feed flow rate variations, the temperature inside the reactor, as well as the mole ratio of the feed to the conversion and syngas produced. The highest conversion achieved at a flow rate 4.6 mL/min, respectively the conversion of CO2 and CH4 is 22% and 88.4% with a ratio syngas produced CO2: CH4 = 1: 1.14. The conversion in the reactor did not change significantly with the increase or decrease the temperature in the reactor. The concentration of CO produced increase with increasing inflow concentration of CO2. The concentration of H2 produced increase with increasing inflow concentration of CH4."

"Kebanyakan dari penghantaran obat untuk mata bagian dalam atau posterior adalah melalui jalur topikal dan sangat jarang melalui jalur sistemik dan sebelum obat dapat mencapai kornea, terlebih dahulu obat tersebut harus melewati pelindung mata yang terdapat dibagian anterior. Salah satu solusi yang dapat dilakukan adalah dengan memformulasikan pelepasan terkendali obat dengan menggunakan modifikasi mikropratikel Poly(lactide acid) (PLA) dan Poly(Lactide-co-Glyoclide Acid) (PLGA) dengan menggunakan surfaktan kationik didodecylammonium bromide (DMAB). Dari penelitian ini, didapatkan hasil uji enkapsulasi dan pemuatan obat untuk PLA Acid Terminated 15,49 ± 0,17 % dan 18,33 ± 0,24 %, PLA Ester Terminated 13,07 ± 0,15 % dan 15,04 ± 0,2 %, serta PLGA (50:50 Acid Terminated) 15,3 ± 0,25 % dan 18,03 ± 0,35 %. Serta kuran partikel yang dihasilkan dengan PVA 0,002% untuk PLA Acid Terminated 4,42 ± 1,57, PLA Ester Terminated 1,26 ± 0,77, serta PLGA (50:50 Acid Terminated) 9,89 ± 2,32.

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Most of the drug to the inner eye or posterior is through topical and very rarely through systemic and before the drug can reach the cornea, the first drug must pass through eye protection contained in anterior. One solution that can be done is to formulate controlled release of drugs using a modified micropartciles Poly (lactide acid) (PLA) and Poly (Lactide-co-Glyoclide acid) (PLGA) using a cationic surfactant didodecylammonium bromide (DMAB).

From this research, test results obtained encapsulation and drug loading for PLA Acid Terminated 15.49 ± 0.17% and 18.33 ± 0.24%, PLA Ester Terminated 13.07 ± 0.15% and 15.04 ± 0 , 2%, and the PLGA (50:50 Acid Terminated) 15.3 ± 0.25% and 18.03 ± 0.35%. As well as the size of the particles produced by the PVA 0.002% for the PLA Acid Terminated 4.42 ± 1.57, 1.26 ± PLA Ester Terminated 0.77, and PLGA (50:50 Acid Terminated) 9.89 ± 2.32."

""Chemical Engineering: An Introduction is designed to enable the student to explore a broad range of activities in which a modern cheical engineer might be involved by focusing on mass and energy balances in liquid-phase processes. Thus, in one semester, the student addresses such problems as the design of a feedback level controller, membrane separation, and hemodialysis, optimal design of a process with chemical reaction and separation, washout in a bioreactor, kinetic and mass transfer limits in a two-phase reactor, and the use of the membrane reactor to overcome equilibrium limits on conversion. Mathematics is employed as a language, but the mathematics is at the most elementary level and serves to reinforce what the student has already studied; nothing more than basic differential and integral calculus is required, together with elementary chemistry. Students using this text will understand what they can expect to do as chemical engineering graduates, and they will appreciate why they need the courses that follow in the core curriculum"--"