Jurnal ILMU DASAR
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Effect of MgO Buffer Layer on The Quality of ZnO Films Grown on C-Sapphire by Plasma-assisted MBE Method
Get PDFoai:jurnal.unej.ac.id:article/57We have investigated the role of low temperature (LT)-MgO buffer layer on the quality of ZnO films grown on c-sapphirebyplasma-assistedmolecularbeamepitaxy(P-MBE)method. EffectofMgObufferthicknessand its annealing were evaluated. We found that surface morphology and crystalline quality of the ZnO layers were improved by controlling of the buffer layers. There is no improvement in morphology and crystalline quality of the ZnO layers if the buffer thickness is less than the critical thickness. The critical thickness is determined to be 1.5 nm. Furthermore, surface, structural, optical, and electrical qualities of the ZnO layers were improved by annealing MgO buffer at high temperature. Dislocation density of the ZnO layer was reduced from 5.3 x109 cm-2 to 1.9 x109 cm-2 by annealing the MgO buffer layer. The results indicate that we can engineer defect in highly mismatched heteroepitaxial using buffer layer
On Total Vertex Irregularity Strength of Cocktail Party Graph
Get PDFA vertex irregular total k-labeling of a graph G is a function λ from both the vertex and the edge sets to {1,2,3,ïŒ,k} such that for every pair of distinct vertices u and x, λ(u)+∑λ(uv)≠λ(x)+∑λ(xy). uv∈E xy∈E. The integer k is called the total vertex irregularity strength, denoted by tvs (G ) , is the minimum value of the largest label over all such irregular assignments. In this paper, we prove that the total vertex irregularity strength of the Cocktail Party graph H2,n ,that is tvs(H2,n )= 3 for n ≥ 3
Modeling Total Maintenance Cost of a Repairable System in Some Bounded Time Interval
Get PDFIn this paper we model the total maintenance cost of a repairable system where the inter-maintenance times are modeled as discrete-time and continuous-time renewal processes. The maintenance cost is assumed to be a function of the lifetime of the system. We derive the probability distribution, including the mean and the variance, of the total maintenance cost. The results are presented in the form of generating functions and Laplace transforms that in general have to be inverted numerically. Some examples are presented in this paper
Phenotypic and genotypic identification of lactic acid bacteria isolated from spontaneous fermentation of unripe var. agung semeru banana (Musa paradisiaca formatypica)
Get PDFLactic acid bacteria (LAB) can be found on food products such as milk and meat products, cerealia, cassava, fruits or vegetable products. The objectives of this research were to identify phenotypic and genotypic of lactic acid bacteria isolated from spontaneous fermentation of unripe var agung semeru banana (Musa paradisiaca formatypica). Phenotypic identification was based on general morphology, physiological test, API and Biolog system. Genotypic identification used polymerase chain reaction (PCR) method and analyses of 16S rRNA sequence. The result showed that two groups of LAB (FSnh 1 and FSnh A isolate) can use glicerol, D-ribose, D- xylose, D-glucose, D-fructose, D-mannose, methyl α D-gluco pyranoside, N-acetyl glucosamine, esculin ferric citrate, salicin, D-celiobiose, D-saccharose, gentibiose and potassium gluconate as carbon source. Beside that FSnh 1 isolate used D-galactose, L-sorbose, L-rhamnose, and amygdalin, while FSnh A isolate used metil αD- glukopiranosa, arbutin, D-maltose, D-lactose, D-trehalose, D-turanose, and potassium 5-ketogluconate as carbon source. The genotypic identification showed that Lactobacillus sp associated with the spontaneous fermentation of var agung semeru banana were identified as Lactobacillus salivarus and Lactobacillus fructivorans
Study of Dehydration of Ricinoleic of Castor Oil By P2O5
Get PDFThe aim of this research is to find out the best temperature, time and amount of dehydrator on dehyration of ricinoleic of castor oil by P2O5. Dehydration as means to obtain linoleic and CLA (conjugated linoleic acid) as glyseride forms. Dehydration was carried out using various temperature, time and amount of dehydrator. The reaction medium was maintained under vacuum through by silica gel to reduced water, gentle bubling with nitrogen thorough by Mg to prevent oxidation, and used Zn powder as an antipolymerization agent. Dehydration was followed by GC which the best result was caused the lowest ricinoleic and the highets linoleic and CLA. Identification was done by FTIR, UV and GC- MS and it was compared with the standard. The best dehydration was obtain for 200oC, 3% (w/w) P2O5, and 4 h with a convertion factor (yield) of 97,94%. The composition of best result was: 1.02% (9c – 12c) linoleic, 41.97% (9c/t – 12t/c) linoleic, 19.50% (9c/t-12t/c) CLA, 4.89% (9t – 12t)linoleic,19.79%(9t–11t)CLA and0.94%ricinoleic.TheratioofCLA:linoleicofdehydrated was 0.82 : 1 or 76.18 % compared to the standard CLA with the proportions of 1.45:1
Triterpenoid Pentacyclic Antimalarial Activity from the Leaves of Erythrina variegata
Get PDFIn the course of our continuing research for novel antimalarial agent from Indonesian plants, the methanol extract of the Erythrina variegata leaves showed significant antimalarial activity against Plasmodium falciparum strain K1 in vitro with IC50 6.8 μg/mL. The methanol extract was separated by using variety of chromatography techniques. The chemical structure of an antimalarial compound was determined on the basis of spectroscopic evidence and compared to previous data then this compound is identified as a pentacyclic triterpenoid oleane derivative, namely 3,22,23-trihydroxy-oleane-12-ene. The pentacyclic triterpenoid, 3,22,23-trihydroxy-oleane- 12-ene showed antimalarial activity against 3D7 and K1 strains with IC50 4.3 μg/mL and 24 μg/mL, respectively. These results strongly suggested that E. variegata is a promising sources of antimalarial agents
Spline Regression Modelling for Health Problem: Study of Knot and Confidence Interval
Get PDFThis article aimed to study about knot and confidence interval for health science using spline nonparameteric regression.The study used simulation and real data. The result showed that numbers of knot should be placed according to the quantil variable in order to get a good estimation of the data function. Inadditon,confidence interval using bayesian and bootstrap method gave no different result for a small sample size whereas for a big sample size bootstrap gave narrower interval
On Ï„ [M ]-Cohereditary Modules
No full textLet R be a ring with unity and N a left R-module. Then N is said linearly independent to R (or N is R-linearly independent) if there exists a monomorphism φ : R(Λ) → N . We can define a generalization of linearly independency relative to an R-module M. N is called M-linearly independent if there exists a monomorphism φ:M(Λ) →N. Amodule  iscalled M-sublinearly independentif  is a factormodule of a module which is M-linearly independent. The set of M-sublinearly independent modules is denoted by τ [M ]. It is easy to see that τ [M ] is subcategory of category R-Mod. Furthermore, any submodule, factor module and external direct sum of module in τ [M ] are also in τ [M ]. A module is called τ [M ]-injective if it is P-injective, for all modules P in τ [M ]. Q is called τ [M ]-cohereditary if Q ∈τ [M ] and any factor module of Q is τ [M ]-injective. In this paper, we study the characterization of category τ [M ]-cohereditary modules. For any Q in τ [M ], Q is a τ [M ]-cohereditary if and only if every submodule of Q-projective module in τ [M ] is Q-projective. Moreover, Q is a τ [M ]-cohereditary if and only if every factor module of Q is a direct summand of module which contains this factor module. Also, we obtain some cohereditary properties of category τ [M ]. There are: for any R-modules P, Q. If Q is P-injective and every submodule of P is Q-projective, then Q is cohereditary (1); if P is Q-projective and Q is cohereditary, then every submodule of P is Q-projective (2); a direct product of modules which τ [M ]-cohereditary is τ [M ]-cohereditary (3). The cohereditary characterization and properties of category τ [M ] above is truly dual of characterization and properties of category τ [M ]
Application of Ionic Liquids ss Reaction Media for The Xylanase Reaction
Get PDFThe potential for performing Thermomyces lanuginosus xylanase-catalyzed reactions on birchwood xylan dissolved in a range of ionic liquids has been investigated. As apparent from the results, some of the selected hydrophobic ionic liquids performed as better facilitators of the hydrolysis reactions than the hydrophilic ones. Thus, the xylanase reaction profiles in these hydrophobic ionic liquids, including [Py1,4]tfsa, [C4MIm]PF6, [P6,6,6,14]BF4, [P6,6,6,14]dca, [P6,6,6,14]bisphosphinate, and [C1MIm]MeSO4, were investigated in greater detail and the conditions for optimum temperature, optimum pH, and kinetic parameters documented. [P6,6,6,14]bisphosphinate was found to be the best ionic liquid producing the highest xylanase activity (84.98 unit/mg protein) at high temperature and pH, namely at 85°C and pH 9.0, respectively, among all of the ionic liquids tested. In addition, this ionic liquid increases the specificity of the xylanase toward xylan, indicated by lower KM (6.42 mg/mL), though it does not observed well on its enzyme’s enhancement rate. Therefore, this study indicates that the application of this ionic liquid for the hydrolysis of real lignocellulosic samples, such as wood pulp, is warranted. Further investigations, outside the scope of this research will be required to validate these observations
A Comparison Study for Agrobacterium-mediated transformation Method in Sugarcane (Saccharum spp L.)
Get PDFIn order to compare transient expression of gus gene driven by CaMV 35S or rice ubiquitin RUBQ2 promoter, Agrobacterium-mediated transformation was conducted using embryogenic callus and suspension cultures of sugarcane. Histochemical observation of GUS activity after co-cultivation showed that rice ubiquitin promoter produced high level of clear blue spots both in embryogenic callus and suspension cultures, while the CaMV35S promoter was not detected. Regenerated shoots from the infected materials were found higher in suspension cultures than embryogenic callus. The results showed that the rice ubiquitin promoter as well as suspension cultures are more efficient for the Agrobacterium-mediated transformation. However, PCR analysis found there was no amplification of DNA neither for CaMV35 nor rice ubiquitin in genome DNA of regenerated shoot. Lacking of integration of the DNA into the genome showed that the regenerated shoots were not truly transformants might due to the presence of somaclonal variation that was common phenomenon in the regeneration from callus. To avoid the presence of somaclonal variation the transformation was then conduced using in vitro plant without intervening callus phase. Basal segment of in vitro plants prepared from axillary buds of sugarcane were used as the explants for the transformation. The histochemical observation of GUS activity showed that almost all of the infected materials partially exhibited blue color on the basal region. Infected in vitro plants showed rapidly grow and multiplied in theselection medium. Further investigation of the transformation using in vitro plants and Agrobacterium harboring SoSUT1 DNA construct driven by rice actin promoter resulted in development of antibiotic resistant sugarcane shoots. Interestingly the PCR analysis found an insertion of the antibiotic DNA fragment into the sugarcane genome DNA. This result suggests that in vitro plant is an effective target tissue for Agrobacterium-mediated transformation in sugarcane