Jurnal ILMU DASAR
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Amperometric biosensor for glucose detection based-on immobilisation of glucose oxidase in acetic cellulose membrane using ferrocene as mediator
Get PDFThe study reported the development of glucose ampherometric biosensor based on immobilization of glucose oxidase on cellulose acetate membrane with ferrocene as a mediator. Biosensor was designed with model Fc, GOx, CP / GOx / CA where ferrocene and the enzyme glucose oxidase on carbon paste in immobilizatin on the electrode body in the form of glass tubes and in other parts of the enzyme glucose oxidase in immobilizatin on cellulose acetate membrane with adsorption techniques are placed in electrode tip by using the o-ring. The presence of enzymes immobilization was determined quantitatively by enzyme immobilization was Km value. The results showed the composition of acetone-water in the optimum coagulation bath is 0:100% and 0,0008 g of Optimum ferrocene. Biosensor for measuring glucose in the area amperometri 0,1 to 3 mM with regression coefficient of 0,996, the detection limit of 0,01 mM, sensitivity of 0,989 μA / mM, the reproducibility of 0,07 to 0,3% and lifetime of 1 day. Keywords : Biosensor; glucose oxidase ; acetic cellulose; Ferrocene: Ampherometric
The Dynamic Population of the Bacterial Hydrocarbonoclastic Concorsium in the Crude Oil Sludge Degradation
Get PDFExperiment in laboratory scale has been carried out to study population dynamic of the bacterial hydrocarbonoclastic consorsium in the crude oil sludge degradation being mixed with NPK fertilizer as nitrogen resources. Aerobic test was carried out by putting erlenmeyers in a shaker incubator, 120 rpm shaking speed, at 50°C temperature. During15 days in laboratory scale observation showed that the consortium has the potential to grow up to 50% (v/v) sludge oil load. Maximum growth and maximum growth rate of the consortium in liquid media occurred in the III C treatment (by adding 50% (v/v) sludge oil and by mixing nitrogen in the form of NPK fertilizer amounting 30% (w/v) of added substrat. At the end of the study 7 species of bacteria were identified, 5 of them are of Bacillus sp, which are aerobical. During degradation process, consorsium growths fluctuativelly. There is spesific process to degrade complex substrat by consortium bacteria.. Specifically, this experiment informs that bacterial consortium degradator of crude oil sludge are more efective than monoculture bacterial. Crude oil consists of complex hydrocarbon, in the other hand for each spesies bacteria has spesific enzyme which work on spesific substrat. They only have limited ability. Each bacteria of its corsorsium has dominated the consorsium which is able to use hydrocarbon fraction
Efficiency Calculation Analysis of A-Si:H Solar Cells for Determination of Optimum Filament Temperature in Material Deposition
Get PDFSolar cell efficiency as a function of the energy gap has been simulated by calculating the output current characteristics of the devices based on the distribution of charge carriers, obtained from the solution of the Poisson equation and the Continuity equation. The hydrogenated amorphous silicon (a-Si:H) based solar cell, has simulated in the form of one-dimensional single junction p/i/n. The junction structure of a-SiC:H/a-Si:H/a-Si:H designed have the thickness of 0,015 μm/0,550 μm/0,030 μm, respectively. For simulation, the energy gap has considered constant in the p and n layers, whereas the i layer varies according to the empirical data of energy gap obtained from the deposition parameters of filament temperature. Simulations performed using the finite element method supported by FEMLAB software. Based on simulation results, obtained the highest efficiency of 9.35% corresponds to the lowest energy gap data of 1.706 eV for layer i. This appropriates to the filament temperature of 800oC and subsequently used as the optimum deposition parameters of the material. Keyword: Energy gap, efficiency, FEM, solar cell, hydrogenated amorphous silico
FLOW INJECTION POTENTIOMETRIC ANALYSIS OF ASPARTIC ACID, GLUTAMIC ACID AND ASCORBIC ACID USING PLATINUM ELECTRODES
Get PDFThe presence of  weak acids in solution can be detected using a potentiometric detector. Platinum was used as a working electrode and Ag/AgCl as a reference electrode. Ascorbic, glutamic and aspartic acid were detected by a platinum electrode in a flow potentiometric system. The influence of pH, flow rate and concentration of phosphate buffers asa a carrier were studied and showed an optimum pH for the detection of ascorbic and glutamic acid at pH 6,5 and pH 7,0 for aspartic acid. Phosphate buffer concentration optimum at 1x10-4M and flow rate of 1,00 mL/min. Linear range for ascorbic and glutamic acid at 2,5 x10-4M to 5x10-2M, with a regression coefficient of  0,974 and 0,958, while for aspartic acid 5x10-4M to 5x10-2M with a regression coefficient 0,911. Detection limit for ascorbic and glutamic acids were 5x10-4M and 1x10-3M for aspartic acid. Sensor reproducibility obtained from variation coefficient  (Kv). Variation coeffiecient (Kv) of ascorbic acids 1,32-1,69%, glutamic acids 0,69- 1,57% and aspartic acid 0,54- 1,29%
Recycle Waste Glass for Thermal Insulator
Get PDFSeries of ceramics from recycle waste glass and mica powder have successfully been made and their physical properties of these glasses which include density, bulk modulus, volume expansion and compressive strength have been determined. Comparison of their physical specification to the conventional insulators has also been made. The results show that these ceramics exhibit reasonable mechanical, thermal and physical properties to be a potential thermal insulator.Â
Production Optimization and Cellulose System Characterization of Bacillus circulans Local Strain Using Inducer Avicel
Get PDFExploration of aerobic bacteria which can produce cellulase system is very important to discover potential celulase resourse which can hydrolysis lignocelulose waste into glucose. The aimed of this researched were determine optimum condition of cellulase system production in Berg’s media with avicel as inducer and it’s characterization. Bacillus circulans local strain from laboratory of Microbiology ITB produced consist of CMC- ase(111.11U/mL)andavicelas (55.56U/mL) in Berg’s medium contain 0.5% avicel, pH=9.0 and 5 days of incubation. Characteristic of this cellulase system were: (1) optimum level of CMC-ase (129.97 U/mL) and avicelase (87.96 U/mL) was obtained at pH= 7.0, temperature 50oC and 2 hours incubation, (2) Vmaks and Km of CMC-ase was 1000 μg glucose/hour and 5%, Vmaks and Km of avicelase was 200 μg glucose/hour and 1.2%, (3) capable of hidrolizing sugarcane, corn cob and rice bran during optimum condition and released glucose 262 ppm, 81 ppm and 78 ppm. This research encouraged that Bacillus circulans capable of producing cellulose system with high activity and suggested to degradated lignocelluloses as feedstocks of bioetanol
Estimation and Statistical Test in Bivariate Binary Probit Model
Get PDFOne of the models that can be used to analyze two binary response variables data is bivariate binary probit model. This paper tried to estimate the parameters of bivariate binary probit model using Maximum Likelihood Estimationmethod, whereastoget the statistical test using Maximum Likelihood Ratio Test method
A Study of Solid-Liquid Extraction with HF And HNO3 as Solvent for Determination of Cr and Cu in the River Sediment near the Muria Nuclear Power Plant
Get PDFA Study of solid-liquid extraction for determination of Cr and Cu in the river sediment near the Muria Nuclear Power Plant has been studied. The river sediment assayed is in Kancilan, Balong, Suru, Dombang, and Wareng rivers. A study of solid liquid extraction focus on the optimum condition of extraction such as: concentrations of HF and HNO3 as are solvent, the extraction time, the accurate of this method; and comparing HF+ HNO3 solvent ability with HNO3 4N + HCl 0.7N and HCl 0.5N in extracting Cr and Cu in the river sediment. Determination of Cr and Cu concentration uses Atomic Absorpton Spectrometry. The research result shows that the optimum condition of extraction obtained in HF and HNO3 concentrations is 40% and 65% v/v respectively; and the extraction time is 5 hours. This research method shows good accuracy that is 84.810 % and 102.461 % for Cr and Cu respectively. In comparing the solvent ability to extract metal, it is obtained that HF 40% + HNO3 65% solvent is the best solvent in Cr metal extraction, whereas HNO3 4N + HCl 0.7N solvent is the best solvent in Cu metal extraction from the river sediment sample
On The Graphs and Their Complements with Prescribed Circumference
Get PDFLet Gt(n) be the class of connected graphs on n vertices having the longest cycle of length t and let G ∈ Gt(n). Woodall (1976) determined the maximum number of edges of G. An alternative proof and characterization of the extremal (edge-maximal) graphs given by Caccetta & Vijayan (1991). The edge-maximal graphs have the property that their complements are either disconnected or have a cycle going through each vertex (i.e. they are hamiltonian). This motivates us to investigate connected graphs with prescribed circumference (length of the longest cycle) having connected complements with cycles . More specifically, we focus our investigations on the class G (n, c, c) denoting the class of connected graphs on n vertices having circumference c and whose connected complements have circumference c. The problem of interest is that of determining the bounds of the number of edges of a graph G∈ G(n, c, c) and characterize the extremal graphs of G(n, c, c). We discuss the class G (n, c, c) and present some results for small c. In particular for c=4 and c =n-2, we provide a complete solution
In Vitro Regeneration of Three Gladiolus Cultivars Using Cormel Explants
Get PDF In vitro technique was dedicated to alleviate the technical problems in conventional propagation of gladiolus for healthy planting material production in marketable quantities. Two experimental series were conducted in non factorial and factorial designs respectively. Cormels of three gladiolus cultivars namely Kaifa, Clara and Nabila were inoculated into free hormone media for plantlet establishment and dormancy breaking observations among genotypes. The established plantlets were then deflasked into solidified MS + 0.5 mg/l NAA with various BA concentrations (1, 2, 3 and 4 mg/l). A randomized complete experiment with seven replications was designed to accomplish these subsequent experiment to determine optimal BA for shoot-leaves initiations and complete plantlet formations. The results showed that in free hormone media, the dormancy breakings of cormel were varied among cultivars tested. The variation among cultivars was also detected on the level of BA for optimum shoot and leaf formations. 2 mg/l BA gave highest shoot and leaves formations for cv. Nabila while higher concentrations needed by other two cultivars. Thus, BA concentrations ranged from 2–3 mg/l were recommended shoot inductions on in vitro propagation of gladiolus