bluuebunny/crossref_metadata_2025_split huggingface dataset:
COORDINATION STATE AND AGGREGATION PROCESS OF BACTERIOCHLOROPHYLL A AND ITS DERIVATIVES : STUDY ON ACETONE-WATER AND METHANOL-WATER SOLVENTS
Authors: Heriyanto Heriyanto , Trihandaru Suryasatriya , Limantara Leenawaty 
Published: January 2019

Research on bacteriochlorophyll (BChl) a and its derivatives had been conducted to determine the coordination state and the aggregation process in acetone-water and methanol-water. The results showed that there were mainly two absorption peaks in BChl a and its derivatives, namely: Qx and Qy that were very sensitive to coordination state and aggregation process. The coordination state of pigment could be determined based on Qx absorption peak that was influenced by solvents. In addition, the donor number (DN) and taft parameters (β and π*) from each sovents could also be used to determine the coordination state. One or two of axial coordination toward center metal of BChl a and its derivatives have to be filled by donor electron as a foreign nucleophile. Mg-BChl was exist as five-coordinate complexes in acetone but as six-coordinate complexes in methanol. Five-coordinate complexes of Zn-BChl was occurred either in acetone or methanol. Cu-BChl was exist as four-coordinate complexes in acetone but altered to five-coordinate complexes in methanol. The agregation process was influenced by the existence of water added in pigment solution. The order of Mg-BChl a and its derivatives abilities to form new aggregate in acetone-water and methanol-water, in regard of water-addition percentage was as follow: Cu-BChl > Zn-BChl > Mg-BChl. Methanol was the solvent that could form aggregate of Mg-BChl and its derivatives at lower water-addition percentage compared to acetone. Keywords: aggregation, bacteriochlorophyll & its derivatives, coordination state.
A PRENYLATED FLAVONE FROM THE HEARTWOOD OF Artocarpus scortechinii King (Moraceae)
Authors: Hakim Aliefman 
Published: January 2019

Two prenylated flavones have been successfully isolated from the methanol extract of the heartwood Artocarpus scortechinii King. They were determined as artelastisin and artelastin. It has been reported that artelastisin and artelastin were obtained from Artocarpus elasticus. The cytotoxicity toward cell murine leukemia P-388 showed that artelastisin is active with IC50 3.0 µg/mL. In addition, artelastin is inactive with IC50 5.75 µg/mL. The structures of isolated compounds were determined based on spectroscopy data including UV, IR, 1H and 13C-NMR. These compounds are reported for the fist time from this plant. Keywords: Artocarpus scortechinii King, prenylated flavone, and cell murine leukemia P-388.
TRANSPORT BEHAVIOR OF Cr(III), Cd(II), Pb(II), AND Ag(I) IONS THROUGH BULK LIQUID MEMBRANE CONTAINING <i>p-tert</i>-BUTYLCALIX[4]ARENE–TETRADIETHYLACETAMIDE AS ION CARRIER
Authors: Maming Maming , Jumina Jumina , Siswanta Dwi , Sastrohamidjojo Hardjono , Ohto Keisuke 
Published: January 2019

The study on the transport behavior of Cr(III), Cd(II), Pb(II), and Ag(I) through bulk liquid membrane using p-tert-butylcalix[4]arene-tetradiethylacetamide as ions carrier has been conducted. The aims of this work are to determine the optimum condition, efficiency, and transport selectivity of the carriers for those ions. Both optimum condition and transport efficiency were obtained by determination of the concentration of transported ions with variation of the source phase pH, ion carrier concentration, the nature of decomplexant agent in the receiving phase, and transport time. The transport selectivity of the ion carrier was obtained from the ions competition transport experiments. The amount of Cr(III), Pb(II), Cd(II), and Ag(I) transported across liquid membrane were 11.6, 25.5, 39.5, and 42.1% respectively. The ion carrier is selective for Cd(II), Pb(II), Ag(I), and strongly depends on the nature of decomplexant agent as well as transport mechanism. The remarkable selectivity was shown by the ion carrier to Ag(I) when the transport process was carry out under high concentration of acid in the source phase. Keywords: transport, p-tert-butylcalix[4]arene-tetradiethylacetamide, efficiency, selectivity, bulk liquid membrane, heavy metals
SURFACE MODIFICATION OF SEMICONDUCTOR THIN FILM OF TiO<sub>2</sub> ON GRAPHITE SUBSTRATE BY Cu-ELECTRODEPOSITION
Authors: Rahmawati Fitria , Wahyuningsih Sayekti , Handayani Nurani 
Published: January 2019

Surface modification of graphite/TiO2 has been done by mean of Cu electrodeposition. This research aims to study the effect of Cu electrodeposition on photocatalytic enhancing of TiO2. Electrodeposition has been done using CuSO4 0,4 M as the electrolyte at controlled current. The XRD pattern of modified TiO2 thin film on graphite substrate exhibited new peaks at 2θ= 43-44o and 2θ= 50-51o that have been identified as Cu with crystal cubic system, face-centered crystal lattice and crystallite size of 26-30 nm. CTABr still remains in the material as impurities. Meanwhile, based on morphological analysis, Cu particles are dissipated in the pore of thin film. Graphite/TiO2/Cu has higher photoconversion efficiency than graphite/TiO2. Keywords: semiconductor, graphite/TiO2, Cu electrodeposition
CATALYTIC HYDROCRACKING OF WASTE LUBRICANT OIL INTO LIQUID FUEL FRACTION USING ZnO, Nb<sub>2</sub>O<sub>5</sub>, ACTIVATED NATURAL ZEOLITE AND THEIR MODIFICATION
Authors: Trisunaryanti Wega , Purwono Suryo , Putranto Arista 
Published: January 2019

Catalytic hydrocracking of waste lubricant oil into liquid fuel fraction using ZnO, Nb2O5, activated natural zeolite (ZAAH) and their modification has been investigated. The zeolite was produced in Wonosari, Yogyakarta. Activation of the zeolite was carried out by refluxing with HCl 3M for 30 min, produced the activated natural zeolite (ZAAH). The ZnO/ZAAH catalyst was prepared by impregnation of Zn onto the ZAAH by ion exchange method using salt precursor of Zn(NO3)2.4H2O. The Nb2O5/ZAAH catalyst was prepared by mixing the ZAAH sample with Nb2O5 and oxalic acid solution until the paste was formed. The impregnation of Zn onto Nb2O5/ZAAH was carried out using the same method to that of the ZnO/ZAAH catalyst resulted ZnO/Nb2O5-ZAAH catalyst. Characterization of catalyst includes determination of Zn metal by Atomic Absorption Spectroscopy (AAS), acidity by gravimetric method and catalyst porosity by Surface Area Analyzer (NOVA-1000). Catalytic hydrocracking was carried out in a semi-batch reactor system using ZnO, ZAAH, ZnO/ZAAH and ZnO/Nb2O5-ZAAH catalysts at 450 oC under the H2 flow rate of 15 mL/min. and the ratio of catalyst/feed = 1/5. The composition of liquid products was analyzed by Gas Chromatograpy (GC).The results showed that impregnation of ZnO and/or Nb2O5 on the ZAAH increased the acidity and specific surface area of catalyst. The products of the hydrocracking process were liquid, coke and gas. Conversion of liquid products was increased by the increase of catalyst acidity. The highest liquid product was produced by ZnO/Nb2O5-ZAAH catalyst, 52.97 wt-%, consist of gasoline, 38.87 wt-% and diesel, 14.10 wt-%. Keywords: hydrocracking, waste lubricant oil, liquid fuel fraction
SEPARATION AND IDENTIFICATION OF NORMAL HYDROCARBON, NONADECANE IN THE CABBAGE VEGETABLES SAMPLES (<i>Brassica oleracea VAR. CAPITATA F. ALBA</i>) BY GAS CHROMATOGRAPHY–MASS SPECTROMETRY
Authors: Hossain M. Amzad , Salehuddin S. M. , Kabir M. J. 
Published: January 2019

Toxic normal hydrocarbon (NH), nonadecane in the methanolic extract of the whole of cabbage samples collected from different districts of Bangladesh was analyzed by GC-MS. It was observed that NH deposition on the samples takes place in different morphological parts of the biological materials. The NH, nonadecane, was found in the cabbage samples collected from the highway road side by the extraction of methanol. The identification and quantification of the title compounds have not been reported previously in the cabbage sample. Keywords: Cabbage; brassica oleracea var. capitata f. alba; quantification; normal hydrocarbon, nonadecane, GC-MS
CONFORMATIONAL EQUILIBRIUM AND SPECTROSCOPIC PROPERTIES OF CALIX[4]ARENE: THEORETICAL STUDY USING <i>AB INITIO</i> METHOD
Authors: Sudrajat Hanggara , Armunanto Ria 
Published: January 2019

Molecular structures were optimized for the calix[4]arene by ab initio method at the Hartree-Fock level of theory using LANL2DZ and 6-311G basis sets. Conformational equilibrium of four calix[4]arene conformers are reported. The results are compared with experiment, force field, and semiempirical molecular orbital calculations. General trends in relative stabilities of calix[4]arene decrease in following order: cone > partial-cone > 1,2-alternate > 1,3-alternate. The most stable conformer is the cone conformer that is stabilized by an array of four hydrogen bonds and these results agree with the reported experimental observations. All structures were analyzed using theoretical IR, UV-Vis, and 1H NMR spectra attributed to the conformational equilibrium at the Hartree-Fock level of theory using LANL2DZ basis set. Keywords: ab initio calculation, calix[4]arene, conformations, cone
1D AND 2D NMR STUDIES OF BENZYL O–VANILLIN
Authors: Al–Douh Mohammed Hadi , Abd Hamid Shafida , Osman Hasnah 
Published: January 2019

The reaction of o-vanillin A with benzyl bromide B2 in acetone as the solvent and K2CO3 as a base in the presence of tetra-n-butylammonium iodide (TBAI) as catalyst formed benzyl o-vanillin, C. The complete assignments of C using PROTON, APT, DEPT-135, COSY, NOESY, HMQC and HMBC NMR in both CDCl3 and acetone-d6 are discussed, and the coupling constants J are reported in Hertz (Hz). Keywords: 1H NMR; 13C NMR; 2D NMR; Benzyl o-Vanillin
ISOFLAVONES AGLICONE OF TEMPE MALANG FRIED SLICES
Authors: Iskandar Yetti Mulyati , Priatni Sri 
Published: January 2019

Soybean fermentation was carried out by using mixed culture Rhizopus oligosporus C and Rhizopus oryzae L16 (1:1) as inoculum. Incubation places in an incubator at 30 oC for 5 days and assessment of β-glucosidase activity daily was investigated. Isoflavones aglicone of tempe produced in laboratory scale, tempe commercial and fried slices tempe from Malang were analized by chromatography technique. Bioconversion of isoflavonoida in soybean to isoflavone aglicone compounds can be caused by extracelluler enzyme b -glucosidase. The observation showed that fresh tempe Malang was obtained genistein content 15.57 mg/100 g defatted tempe higher than tempe produced from laboratorium scale that was 5.45 mg/100 g defatted tempe. However, genistein content of fried slices tempe from Malang content decreased 25%, that was 11.45 mg/100 g defatted tempe. Tempe prepared at laboratory had the highest specific activity of β-glucosidase at day two that was 1693 U/g protein. Keywords: tempe, Rhizopus oligosporus C, Rhizopus oryzae L16, genistein
PARTIAL CHARACTERIZATION of lipase from COCOA BEANS (<i>Theobroma cacao.</i> L.) of clone PBC 159
Authors: Samsumaharto Ratna Agung 
Published: January 2019

A study was carried out to characterize the cocoa lipase from cocoa beans (Theobroma cacao, L.) of clone PBC 159. The optimum temperature of cocoa lipase was 30-40 °C and the pH optimum was 7.0-8.0. The moleculer weight of the lipase enzyme was in between 45-66 kDa. The results indicate that Km value for cocoa bean lipase was 2.63 mM, when trimyristin was used as a substrate. The incubation of cocoa bean lipase with triolein and tributyrin (as substrate) yielded Km of 11.24 and 35.71 mM, respectively. The Vmax value obtained from the incubation of the lipase with a wide range of substrates, including tributyrin, trimyristin and triolein, are expressed as µmole acid/min/mg protein for cocoa lipase. Vmax values decreased with the increase in the triacylglycerol chain-length, with Vmax values of 27.78, 13.16 and 11.63 µmole acid/min/mg protein when incubated with tributyrin, trimyristin and triolein, respectively. Inhibition of lipase occurred in the presence of diisopropyl flourophosphate, N-bromosuccinimide and 5,5-dithiobis-(-2-nitrobenzoic acid). Keywords: characterization, lipase, cocoa beans
IDENTIFICATION OF SOME CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS IN BANGLADESHI VEHICLES EXHAUST TAR BY GAS CHROMATOGRAPHY-MASS SPECTROPHOTOMETER
Authors: Hossain M. Amzad , Salehuddin S. M. 
Published: January 2019

A more sensitive GC-MS method has been established for the determination of some carcinogenic polycyclic aromatic hydrocarbons (PAHs) in vehicles exhaust tar samples. The tar samples were extracted using dichloromethane (DMC): n-hexane solvent mixture. A multi-layer clean-up (silica gel/sodium sulphate) column was used, followed by glass fiber filter (GFF) paper. The method was successfully applied to determine a number of PAHs present in exhaust tar sample of different vehicles of the Atomic Energy Centre, Dhaka, Bangladesh. Keywords: Carcinogenic polycyclic aromatic hydrocarbons, vehicles tar samples, identification, GC-MS/MS
INVESTIGATION OF STABLE ISOTOPE OF <sup>18</sup>O AND <sup>2</sup>H IN SHALLOW GROUNDWATER FROM KARAWANG AREA
Authors: Pujiindiyati E. Ristin 
Published: January 2019

Karawang area is well known as an agriculture area and 2% area is utilized for industries. Clean water demands increase due to developing industry development and population increasement. The origin of groundwater is necessary to keep the sustainability of water resources in this area. Stable isotopes such as 18O and 2H can be used as a parameter to trace the ground water origin. The methods used were Epstein-Mayeda and Zinc reduction for analysis 18O and 2H, respectively. Sampling period was conducted in major dry season in year 2002. The result showed that evaporation effect had influenced to the content of both isotopes in its shallow groundwater that caused a slope shift from its local meteoric line. The origin of its shallow groundwater was from rainwater infiltrating directly in less than 10 m altitude. Citarum River showed more depleted values in both isotopes compared to shallow groundwater and it indicated that its water might originate from spring at the altitude of 600 m. Keywords: oxygene-18, deuterium, groundwater, isotope
TOXIC NORMAL HYDROCARBONS (NHs) IN THE FISH SAMPLES FROM DIFFERENT PARTS OF BANGLADESH
Authors: Hossain M. Amzad , Salehuddin S. M. 
Published: January 2019

Toxic normal hydrocarbon (NH), nonadecane in the dichloromethane-hexane crude extract of the flesh of fish samples collected from the different districts of Bangladesh was analyzed by GC-MS/MS. It was observed that NH deposition on the samples takes place in different morphological parts of the biological materials. The NH, nonadecane, was found in the fish samples collected from the roadside by the extraction of dichloromethane-hexane mixture solvents. Keywords: Toxic normal hydrocarbon, nonadecane, quantification, Bangladeshi fish GC-MS/MS
ENCAPSULATION OF HORSERADISH PEROXIDASE-GLUCOSE OXIDASE (HRP-GOx) IN SILICA AQUAGEL SYNTHESIZED FROM RICE HULL ASH FOR ENZYMATIC REACTION OF GLUCOSE
Authors: Nuryono Nuryono , Narsito Narsito , Astuti Endang 
Published: January 2019

In recent years, the sol-gel technique has attracted increasing interest as a unique approach to immobilize biomolecules for bioanalytical applications as well as biochemical and biophysical studies. In this research, encapsulation of Horseradish peroxidase-Glucose oxidase (HRP-GOx) enzymes in silica aquagel from rice hull ash by sol-gel process has been carried out. In addition, the effect of several parameters (weight ratio of HRP to GOx, pH, temperature, sodium ion concentration) on enzyme activity was studied, as well. Rice hull ash, which was produced by ashing at 700 °C, was extracted it's silika by NaOH solution 1 M at 100 °C for two hours to produce sodium silikate (Na2SiO3) solution. The Na2SiO3 solution with pH of 13 was added with a strong cation exchanger resin, to produce sol solution with the pH of 4. Encapsulation was emphasized by mixing sol solution and phosphate buffer pH 7 containing HRP-GOx solution at volume ratio of buffer to sol solution 1:5. The mixture was transferred into 96-microwell plate and was aged for 24 hours. Enzymatic reaction was carried out by adding chromogenic solution of phenol and 4-aminoantipyrine (4-AAP) and b-D-glucose solution (as substrate) into the microwell. Enzymatic activity was examined by measuring absorbance of product solution at 490 nm with ELISA reader. Result of enzymatic activity for encapsulated enzymes (SGE) was compared to that for free enzymes (EB). Results showed that at the investigated condition, HRP-GOx enzymes gave high activity at weight ratio of HRP to GOx 10:1 and pH 7 for both SGE and EB. Encapsulation caused the enzymes activity decrease to 53.0±0.2 %. However, SGE was observed to be more stable on pH and temperature changes than EB. Study on the effect of sodium concentration showed that the increase of sodium concentration from 0.10 to 0.37 M decreased the enzymatic activity to 56±0.2%. Reusability test showed that the synthesized SGE was reusable with activity decrease of 60% within 23 days. Keywords: rice hull ash, encapsulation, aquagel, horseradish peroxidase, glucose oxidase
SYNTHESIS OF MESOPOROUS METHYL-SILICA HYBRID FOR ADSORPTION OF ALIZARIN RED-S
Authors: Rusdiarso Bambang , Kunarti Eko Sri , Hamdiani Saprini 
Published: January 2019

Mesoporous methyl-silica hybrid has been synthesized through sol-gel process, by using tetraethylorthosilicate and methyltriethoxysilane as precursors and tartaric acid as a template. The adsorbent was applied to study the adsorption of alizarin red-S. The preparation of methyl-silica hybrid was carried out at various mol ratios of precursors and tartaric acid concentration. The methyl-silica hybrid result was characterized by infrared spectroscopy, X-ray diffraction, and surface area analyzer. Adsorption experiment was conducted to study the effect of pH and Alizarin Red-S concentration on the adsorption capacity of the adsorbent. The adsorbed Alizarin Red-S was calculated from different of Alizarin Red-S concentration before and after adsorption based on the analysis with UV-Vis method. Characterization with Infrared Spectroscopy showed that methyl-silica hybrid has been successfully synthesized as indicated by appearance of characteristic functional group vibrations i.e Si-C, silanol (Si-OH) and siloksan (Si-O-Si). The X-ray diffraction data showed amorphous structure of methyl-silica Hybrid. The Surface Area Analyzer analysis data showed that the pore diameter and surface area of methyl-silica hybrid tended to increase as the template concentration increases. Adsorption study of methyl-silica hybrid showed that the adsorption decreased as the pH was increased. The optimum adsorption was obtained at pH=2.0 with the concentration of Alizarin Red-S of 70 mg/L. Keywords: sol-gel, tartaric acid template, mesoporous, adsorption
KINETICS OF PALM OIL TRANSESTERIFICATION IN METHANOL WITH POTASSIUM HYDROXIDE AS A CATALYST
Authors: Yoeswono Yoeswono , Triyono Triyono , Tahir Iqmal 
Published: January 2019

A study on palm oil transesterification to evaluate the effect of some parameters in the reaction on the reaction kinetics has been carried out. Transesterification was started by preparing potassium methoxide from potassium hydroxide and methanol and then mixed it with the palm oil. An aliquot was taken at certain time interval during transesterification and poured into test tube filled with distilled water to stop the reaction immediately. The oil phase that separated from the glycerol phase by centrifugation was analyzed by 1H-NMR spectrometer to determine the percentage of methyl ester conversion. Temperature and catalyst concentration were varied in order to determine the reaction rate constants, activation energies, pre-exponential factors, and effective collisions. The results showed that palm oil transesterification in methanol with 0.5 and 1 % w/w KOH/palm oil catalyst concentration appeared to follow pseudo-first order reaction. The rate constants increase with temperature. After 13 min of reaction, More methyl esters were formed using KOH 1 % than using 0.5 % w/w KOH/palm oil catalyst concentration. The activation energy (Ea) and pre-exponential factor (A) for reaction using 1 % w/w KOH was lower than those using 0.5 % w/w KOH. Keywords: palm oil, transesterification, catalyst, first order kinetics, activation energy, pre-exponential factor
THE EFFECT OF HYDROGEL DRESSING COPOLYMER POLI(VINYLPIRROLIDONE) (PVP) - k- CARRAGEENAN PREPARED BY RADIATION AND HEALING TIMES ON THE RADIUS REDUCTIONS BURN INJURIED OF WISTAR WHITE RAT
Authors: Erizal Erizal 
Published: January 2019

The pre-clinical study of poly (vinyl pirrolidone) (PVP)-k- carrageenan hydrogel has been carried out. The aim of this study is to investigate the effect of hydrogel for healing burn injuried in the rats. The hydrogels were prepared by g-irradiation of aqueous solutions of 15 wt.-% PVP and 2 wt.-% k- carrageenan at a sterilization dose of 25 kGy. The physico-chemical properties of hydrogels were investigated. The results showed that the hydrogels suitable as candidate for wound dressing with gel fraction of 90 ± 5 (%), the water absorption was 4500 ± 55 (w/w), the water content was 83 ± 2 (%), tensile strength was 1,5 ± 0,1 kg/cm2 and adhesiveness was 0. The effect of the hydrogel as wound dressing was evaluated by attaching to a burn of the back skin of rats as a function of time observation. Advantages of the hydrogel were slightly faster rate of reducing radius diameter of injured burn skin, easy removal without damage to renewed skin. Keywords: hydrogel, irradiation, copolymer, PVP, k carrageenan, diameter
PHOTODYNAMIC THERAPY: NEW LIGHT IN MEDICINE WORLD
Authors: Santosa Venny , Limantara Leenawaty 
Published: January 2019

Photodynamic therapy (PDT) is a considerably new kind of photochemotherapeutic treatment in medical field. It combines the use of three components, which are a photosensitizer, light and oxygen. Photosensitizer is a compound activated by light. The application can be oral, topical or intravenous. It usually member of porphyrin group with ampiphilic characteristics. Photosensitizer can be of generation I, II or III, each generation step develops more specificity, selectivity and deeper tissue application. This review will discuss photosensitizer development consecutively, with its benefit and lackness. The light used is usually on red region, while the oxygen is involved in reactive oxygen species generation. Its mechanism action can go through either in type I or type II reaction. This kind of therapy is usually being used in oncology, especially in superficial and in-lining cancers, dermatology and ophthalmology field. This therapy can be safely given to patients with complication and has distinct advantages compare with other treatment such as chemotherapy and surgery. It also considerably has lesser side effects and risks. Broader application is being developed through various experiments and photosensitizer modification. Keywords: light spectrum, photoactivation, photodynamic therapy, photosensitizer
EFFECT OF CERIUM ON HYDRODESULFURIZATION CATALYST PERFORMANCE
Authors: Triyono Triyono , Trisunaryanti Wega 
Published: January 2019

Effect of cerium on hydrodesulfurization catalysts performance have been investigated. The catalysts were Pt or Pt-Ce supported on zeolite. The Pt/Zeolite catalyst was prepared by wet impregnation method, while that of Pt-Ce/Zeolite catalyst was prepared using coimpregnation method both were followed by drying, calcination, oxidation and reduction. The catalysts activity test was performed in a micro reactor and products composition was determined using gas chromatography. The results showed that cerium enhanced catalyst performance especially catalyst lifetime. Therefore, the catalysts have higher tendency to remain active for longer period. Due to its function, cerium might be used as a promoter of hydrodesulfurization catalysts. Keywords: Cerium, hydrodesulfurization, promoter, life time