Journal of Mathematical and Fundamental Sciences
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Demethylation of Quinine Using Anhydrous Aluminium Trichloride
Get PDFQuinine is a natural alkaloid having a methoxy group bound to quinoline ring and an allyl group bound to quinuclidine ring. Demethylation of quinine applying strong acid such as HBr or HI at high temperature was unsuccessful. The aim of this research was to obtain demethylated quinine by means of mild and selective demethylation procedure to prevent the addition reaction of allyl group. Selective demethylation of quinine has been carried out using anhydrous aluminium trichloride as reagent. The demethylation product was achieved in 68.12% yield by mole ratio of quinine to anhydrous aluminium trichloride of 1 to 4 in dried methylene chloride under nitrogen atmosphere. The reaction was firstly carried out at 0°C for 4 h and after the reaction mixture reached room temperature, the reaction was continued up to 24 h
Immobilization of Amino Acids Leucine and Glycine on Polypyrrole for Biosensor Applications: A Density Functional Theory Study
Get PDFAdsorption based on the immobilization of amino acids, i.e. leucine and glycine, on the surface of undoped polypyrrole (Ppy) is investigated. Calculations are done based on density functional theory using Gaussian03 software and applying GGA with 6-31G(d) basis set and exchange-correlation model of PBE (Perdew, Burke, Ernzerhof) level of theory. The energy of the Ppy doped with amino acids are minimized with respect to the orientation and distance of the amino acids to the Ppy. Neutral leucine carboxyl shows greater binding energy as compared to that other leucine configurations. It has adsorption energy of 0.25 eV at optimum distance of 2.2 Ã… from the surface of Ppy. As for the glycine, the zwitterionic carboxyl exhibits the strongest binding energy among other glycine configurations. It has adsorption energy of 0.76 eV at optimum distance of 1.7 Ã… from the surface of Ppy. The adsorption processes for both amino acids should proceed easily because the activation barriers are either absent or very small
Flavonoids from Macaranga lowii
Get PDFA new isoprenylated dihydroflavonol derivative, macalowiinin (1), together with two known flavonoids 4'-O-methyl-8-isoprenylnaringenin (2) and 4'-O-methyl-5,7,4'-trihydroxyflavone (3) (= acasetin), have been isolated from the methanol extract of the leaves of Macaranga lowii. The structures of these compounds were determined based on UV, NMR, and mass spectral data, and optical rotation. Preliminary cytotoxic evaluation of compounds 1 "“ 3 against P-388 cells showed that compound 3 is the most active with IC50 was 58.7 mM
Synthesis and Theoretical Study of Zinc(II) and Nickel(II)-Complexes of 5-Methoxyisatin 3-[N-(4-chlorophenyl)thiosemicarbazone]
Get PDFZinc(II) and nickel(II)-complexes of 5-methoxyisatin 3-[N-(4-chlorophenyl) thiosemicarbazone] (H2MICP) were synthesized and characterized by infrared, ultraviolet and 1H-NMR spectroscopies as well as elemental analysis. Model of H2MICP and its zinc(II) and nickel(II)-complexes were optimized with B3LYP method using 6-31G(d,p), 6-311G(d,p), 6-311++G(d,p), 6-311++G(2d,2p) basis sets. The calculated 1H-NMR, UV and IR spectra data were compared with experimental results. In addition to the Natural Bond Orbital (NBO) analysis of H2MICP and its Zinc(II) and Nickel(II) complexes, Fukui functions of H2MICP were also reported
Computer Model Development on Contact-Stabilization Wastewater Treatment Systems
Get PDFComputer model is developed to relate parameters that determine the performance of a contact-stabilization system. Based on mass and substrate balance in the system, relationships between the variables are developed, then simulations using various values of the parameters can produce trend lines indicating the behavior of a system as well as the required conditions to reach an expected performance. When the operating conditions, such as recycled sludge and wasted sludge are changed, the model demonstrates alterations of the performance consistent to the developed mathematical relationships. Additionally, the computer model shows that the results could produce further explanation on phenomena of biological processes in contact-stabilization systems
Pengolahan Limbah Cair Emulsi Minyak dengan Proses Membran Ultrafiltrasi Dua-tahap Aliran Cross-flow
Get PDFA study on the use of cellulosa acetate membrane using cross-flow system to treat oil-water emulsion waste came from metal cutting process of automotive industry has been done. The objectives of this research are to treat oil water emulsion waste and to see the impact of pretreatment process to membrane performance. The separation mechanism of ultrafiltration process is filtration. The molecule which is smaller than membrane pore size will pass the membrane other wise, the bigger one will be rejected. The ultrafiltration process performance is determined by permeate fluks and rejection. The material of membrane used in this process is cellulosa acetate membrane with 12 % composition for first stage operation and 15 % one for second stage operation, each on 90 minutes operation time. Operation pressure used was 3,5 Bar. There are two type feeding operation treated by membrane, feeding without pretreatment and feeding with pretreatment. On the first stage membrane operation, waste without pretreatment applied flux at 17,03 L/m2.h, and for waste with pretreatment the applied flux was 59,05 L/m2.h. On the second stage membrane operation the applied flux of waste without pretreatment was 22,08 L/m2.h, and the flux of waste with pretreatment was 24,86 L/m2.h. Overall COD and surfaktan rejection involving two stage membrane operation, which COD rejection was 96,57% for waste without pretreatment, and surfactant rejection was 96,35 %. Meanwhile, for waste with pretreatment the COD rejection was 98,56 % and the surfactant rejection 97,44%. It is concluded that pretreatment process give a benefit to increase fluks and goof quality permeate
Penentuan Tinggi Orthometrik Gunung Semeru Berdasarkan Data Survei GPS dan Model Geoid EGM 1996
Get PDFSemeru is the highest mountain in Java island with an altitude of about +3676 m above the sea level. This altitude was measured during the Dutch colonial times using the Triangulation method, which is based on angles measurements using a theodolite on the measurement points. At the present times, with the advancement in positioning technology and better knowledge on the Earth's gravity field, an orthometric altitude of a mountain can also be determined by utilizing GPS satellites observation data and a global geopotential model. In this paper, the methodology, mechanism and results of the altitude determination of Semeru mountain using the August 2003 and August 2004 GPS survey data and EGM 1996 geoid model will be described and discussed.The obtained results show that the altitude of Semeru at the present times is about +3677 m above the mean sea level.The paper will be sum up with some closing remarks
Beam Positions Optimization to Achieve Improved CT Images with Limited Data
Get PDF In radiotherapy planning, margins are used to account for the uncertainties due to internal organ and patient motion as well as set-up error. Improvement in radiotherapy treatments may be achieved by reducing the set-up uncertainty and thus treatment margins allowing a higher dose to be delivered to the target volume. It is important to be able to verify the success of the treatment by determining the position of patient and the dose deposited in the patient at each fraction. One possibility for achieving this would be to collect limited information while the patient is on the treatment couch. The aim of this study is to develop a method for determining intelligent angles to use to reconstruct an image for dose verification.A method optimizing the angles based on an objective function is required. The methods developed here are based on image correlation and projection correlation that have been investigated previously. Two optimization methods, deterministic and stochastic (simulated annealing), were also assessed. The effectiveness and practicality of each of these combinations were compared
Estimating Oil Reservoir Permeability and Porosity from Two Interacting Wells
Get PDFThe Ensemble Kalman Filter (EnKF) can be used as a method to estimate reservoir parameters, such as permeability and porosity. These parameters play an important role in characterizing reservoir performance. The EnKF is a sequential estimation method that uses the parameters at t "“ 1 (called prior) to estimate the parameters at t adjusted by observations at t (called posterior). In this paper, the EnKF was used to estimate the reservoir parameters for the case of a linear flow of two interacting production-injection oil wells. The Laplace transform was used to obtain an analytical solution of the diffusivity equation. A state space representation was generated using the analytical solution. A simulation study showed that the proposed method can be used successfully to estimate the reservoir parameters using well-pressure observations
Pengukuran Parameter Seismik dan Difraksi Sinar-X (XRD) pada Batuan Karbonat Formasi Parigi
Get PDFSubstitusi fluida merupakan bagian dari studi seismik untuk memodelkan dan menghitung berbagai macam skenario substitusi fluida yang memberi petunjuk pada pengamatan respon AVO (Amplitude Variation with Offset) dan data seismik post stack. Substitusi fluida melibatkan persamaan Gassmann yang akan mengestimasi efek fluida terhadap parameter modulus bulk. Prediksi parameter modulus bulk ini dapat dipakai untuk mencari keberadaan hidrokarbon.Eksperimen dilakukan terhadap beberapa sampel core batuan karbonat formasi Parigi di daerah Cirebon. Batuan karbonat yang diprediksi berkategori reef dengan kandungan mineral Calcite yang dominan. Kemudian diukur di dalam laboratorium seismik batuan tekanan tinggi dengan variasi tekanan berupa overburden dan pore pressure. Pengamatan dilakukan saat fluida berupa air disubstitusikan ke dalam batuan serta mengamati efek fluida yang terjadi ketika variasi tekanan diberikan. Pengaruh dari kehadiran fluida ini akan digunakan untuk menjelaskan efek substitusi fluida pada batuan karbonat.Kenaikan atau bertambahnya kecepatan gelombang-P ini berbanding lurus dengan modulus bulk dari fluida pengisi pori, sedangkan kecepatan gelombang-S cenderung menurun dengan kehadiran fluida. Hal ini menyatakan bahwa asumsi Gassmann tidak berlaku untuk batuan karbonat