bluuebunny/crossref_metadata_2025_split huggingface dataset:
PREPARATION AND CHARACTERIZATION OF POROUS ALUMINA-TITANIA AEROGEL VIA CO<sub>2</sub> SUPERCRITICAL EXTRACTION
Authors: Tursiloadi Silvester , Imai Hiroaki , Hirashima Hiroshi 
Published: January 2019

Porous aerogel of titania-alumina were prepared by hydrolysis of metal alkoxides and supercritical extraction of the solvent. Monolithic wet-gel of 0.2TiO2-0.8Al2O3, prepared by hydrolysis of metal alkoxides in alcoholic solutions, and the solvent in wet gel was supercritically extracted in CO2 at 60oC and 24Mpa for 2h. Thermal evolutions of the microstructure of the gel were evaluated by differential thermal analysis (TG-DTA), N2 adsorption, scanning electron microscopy and X-ray diffractometer. After calcination at 500oC, the specific surface area of the gel was more than 400m2g-1. The average pore radius of aerogel, about 8nm, was about 50% of that for alumina aerogel, but about 4 times larger than that of the xerogel. The specific surface area of the aerogel was more than 200m2g-1 after calcination at 800oC. The pore size and pore volume of aerogel hardly decreased after calcinations at 800oC, although those values of the xerogel remarkably decreased after calcination up to 800oC. The thermal stability of the microstructure of porous titania-alumina is improved by supercritical extraction. Keywords: Oxides, Sol-gel chemistry, X-ray diffraction, Infrared pectroscopy
DETERMINATION OF RATE CONSTANT AND STABILITY OF ADSORPTION IN COMPETITIVE ADSORPTION OF Cr(III) AND Cd(II) ON HUMIC ACID BY USING THE NEW MODEL OF KINETIC FORMULATION
Authors: Suyanta Suyanta , Sudiono Sri , Santosa Sri Juari 
Published: January 2019

Determination of rate and stability constants of adsorption in competitive adsorption of Cr(III) and Cd(II) on humic acid by using the new model of kinetic formulation has been done. The new model based on assumption that those adsorption was first order adsorption rearched equilibrium. Humic acid was isolated from Peat moss of Silaut- West Sumatra by modificated Schnitzer method. Humic acid characterization was conducted by using infrared spectrophotometer with KBR pellet method. The experiment of kinetic adsorption was conducted in batch system reactor using erlenmeyer at 25 ± 0.01 oC of water steam bath and in a series of sampling procedure. Initial concentration of both Cr(III) and Cd(II) was 4x10-4 M. Thirty milligrams of humic acid was added to 200 mL of metal solution, and then stirred continuously. At the fixed periode of time, 10 mL of sample was taken using a syringe, then filterd with 0.45 µm filter paper. Concentration of Cr(III) and Cd(II) in the filtrate was determinated by AAS, while that was adsorbed by humic acid was equal to difference between initial and equilibrium concentration. It was concluded that competitive adsorption of Cr(III) and Cd(II) on humic acid was first order adsorption rearched equilibrium as proposed in this research. Adsorption rate constant of Cr(III) on humic acid at competitive condition was greater than of Cd(II), but on the contrary for stability constant (K). Competition between Cr(III) and Cd(II) to interact with the active side of humic acid was dominated by Cr(III). Keywords: rate constant, stability and competitive adsorption
REDUCTION AND OXIDATION PROCESSES OF CHROMIUM IN HUMIC ACID SUBFRACTION-SENSITIZED PHOTOCATALYST
Authors: Santoso Uripto Trisno , Herdiansyah Herdiansyah , Santosa Sri Juari , Siswanta Dwi 
Published: January 2019

The process of reduction and oxidation of soluble chromium in humic acid subfraction-sensitized photocatalyst was studied. Humic acid was extracted from peat soil sampled in Gambut District, South Kalimantan. Humic acid (HA) was fractionated to humic acid subfraction (HAS) by centrifugation method. ZnO and TiO2 were applied as the photocatalysts produced by Merck, suspended in solution of 2 g/L. Two germicide UV lamps 30 watt (Philip®) was placed in a box at 20 cm above the samples. The results showed that HA or HAS sensitized the photoreduction of Cr(VI) by photocatalyst. The low molecular weight of HAS is more effective to act as sensitizer than the high molecular weight one. The yield of the photoreduction of Cr(VI) with photocatalysts enhanced both in the presence of Fe(II) ion and HAS. UV irradiation of the MnO4- solutions containing Cr(III) induced the photooxidation of Cr(III) to Cr(VI). The presence of Fe(III) or HAS doesn't inhibit significantly. The inhibition is enhanced by the present of both HAS and Fe(II) or HAS and Fe(III). This inhibition is enhanced more by the presence of ZnO or TiO2 photocalysts. Keywords: reduction, oxidation, chromium, humic acid, photocatalyst
CORRELATION BETWEEN PREEXPONENTIAL FACTOR AND ACTIVATION ENERGY OF ISOAMYLALCOHOL HYDROGENOLYSIS ON PLATINUM CATALYSTS
Authors: Triyono Triyono 
Published: January 2019

Arrhenius equation stated that reaction will proceed faster at higher temperature and with lower activation energy (Ea). Many literatures reported that preexponential factor (A) is constant for certain reaction and there is no relation between A and Ea. Experiment on the reaction of isoamylalcohol hydrogenolysis showed that logarithm of A increased linearly with Ea. The result of this investigation suggests that the rate of a process is affected by the number of active centers on the surface of a catalysts, which influences the value of the pre-exponential term in the expression for the rate constant of a reaction. An increase in the number of active centers corresponds to a higher value of A, the active centers would be less effective and is attended by a growth in the value of Ea. Therefore, reaction with lower activation energy will not always has higher reaction rate due to decreasing of Ea. Keywords: isoamylalcohol hydrogenolysis, preexponential factor, activation energy.
SUSCEPTIBILY OF <i>Aeromonar hydrophylla</i> BACTERIA ISOLATED FROM UNHEALTHY BAUNG FISH (<i>Mystus nemurus</i>) TOWARDS ANTIMICROBIAL AGENTS
Authors: Taufik Pipik , Bastiawan Dayat 
Published: January 2019

The susceptibility of Aeromonas hydrophila isolated from ikan baung (Mystus nemurus) to antimicrobial agents was carried out. The objective of study is to know the kind of antimicrobial agents for the control aeromonasis of Mystus nemurus. Tryptic soy agar (TSA) plate consisted 106 cells/plate of A. hydrophila on its surface was kept paper disk consisted antimicrobial agent, than incubated on 30 0C for 24 hours. The results showed that from 10 isolates to be tested, 5 isolates were resistant, 2 isolates were intermediate and 3 isolates were sensitive to tetracycline and chloramphenicol respectively; one isolate was resistant, 6 isolates were intermediate and 2 isolates were sensitive to nalidixic acid. Minimal in hibitory concentration (MIC) of tetracycline and chlorampenicol to the sensitive isolates were 0.5 ppm respectively. Keywords: The susceptibility, Aeromonas hydrophila, antimicrobial agents
QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIP ANALYSIS OF CURCUMIN AND ITS DERIVATIVES AS GST INHIBITORS BASED ON COMPUTATIONAL CHEMISTRY CALCULATION
Authors: Istyastono Enade Perdana , Martono Sudibyo , Pranowo Harno Dwi , Tahir Iqmal 
Published: January 2019

The Quantitative Structure-Activity Relationship (QSAR) study was established on curcumin and its derivatives as glutathione S-transferase(s) (GSTs) inhibitors using atomic net charges as the descriptors. The charges were resulted by semiempirical AM1 and PM3 quantum-chemical calculations using computational chemistry approach. The inhibition activity was expressed as the concentration that gave 50% inhibition of GSTs activity (IC50). The selection of the best QSAR equation models was determined by multiple linear regression analysis. This research was related to the nature of GSTs as multifunctional enzymes, which play an important role in the detoxification of electrophilic compounds, the process of inflammation and the effectivity of anticancer compounds. The result showed that AM1 semiempirical method gave better descriptor for the construction of QSAR equation model than PM3 did. The best QSAR equation model was described by : log 1/IC50 = -2,238 - 17,326 qC2' + 1,876 qC4' + 9,200 qC6' The equation was significant at 95% level with statistical parameters : n = 10, m = 3, r­ = 0,839, SE = 0,254, F = 4,764, F/Ftable = 1,001. Keywords: QSAR analysis, curcumin, glutathione S-transferase(s) (GSTs), atomic net charge
PREPARATION OF Ni-Mo/MORDENITE CATALYSTS UNDER THE VARIATION OF Mo/Ni RATIO AND THEIR CHARACTERIZATIONS FOR STEARIC ACID CONVERSION
Authors: Trisunaryanti Wega , Triyono Triyono , A Denty Fibirna 
Published: January 2019

The preparation of Ni-Mo/Mordenite catalysts with variation of Mo/Ni ratio and their characterizations for conversion of stearic acid have been conducted. The catalysts were prepared by loading a small amount of nickel and/or molybdenum on H-Mordenite (H-Mor) with total metal content = 1 wt% based on the mordenite. The metals was supported on to the mordenite by impregnation method using nickel nitrate and/or ammonium heptamolybdate solution. The Mo/Ni ratio was varied as follows 0/1, 1/0, 1/1, 2/1, and 3/1 produced Ni/Mor, Mo/Mor, Ni1-Mo1/Mor, Ni1-Mo2/Mor and Ni1-Mo3/Mor catalyst respectively. The catalysts were then calcinated with nitrogen, oxidized with oxygen and reduced by hydrogen. The characterizations of catalyst were carried out by measuring Ni and Mo contents using atomic absorbtion spectroscopy (AAS), acidity by ammonia vapour adsorption, specific surface area and pore size distribution by nitrogen gas adsorption (NOVA-1000). The catalyst characters on conversion of stearic acid were performed in a flow reaction system at 4000C under hydrogen stream (10 mL/min). The AAS analyses showed that the metal impregnated on to the H-Mor sample were consistent to the initial metal concentrations. The loading of Ni and/or Mo enhanced the acidity, however decreased the specific surface area and total pore volume of the H-Mor sample. The higher the acidity the higher the conversion of stearic acid and the lower the coke formation. The other catalyst characters gave the variation effects toward the stearic acid conversion. The conversions of stearic acid were 34,52%, 43,33%, 65,10%, 80,10%, 86,42% and 95,72% produced by Ni1-Mo3/Mor, H-Mor, Mo/Mor, Ni/Mor, Ni1-Mo2/Mor and Ni1-Mo1/Mor catalyst, respectively. Keywords: Ni-Mo/Mordenite, impregnation, stearic acid, Ni1-Mo1/Mordenite
STUDY OF DOUBLE PROTONS MIGRATION MECHANISM IN SUPRAMOLECULAR STRUCTURES OF ACETIC ACID-WATER AND ACETIC ACID-AMMONIA BY AB INITIO METHOD
Authors: Wijaya Karna , Tahir Iqmal , Harnowo Harnowo 
Published: January 2019

The theoretical study of double protons migration mechanism on acetic acid-water and acetic acid-ammonia associations has been carried out. The research covered determinations the reactant, transition state and product structures. To gain the goal, the research was conducted in three steps, i.e. (i) designing the reactant, transition state and product models, (ii) optimizing of structures, and (iii) calculating of their uncorrected total energy and frequencies with ab initio methods (basis set 6-31G**). All calculations were performed using Hyperchem ver 5.0 for Windows and Gaussian 94W package program. The computational study result showed that the calculated structures were in good agreement with the hypothetical structures. Keywords: double protons migration, acetic acid, water, ammonia, molecular mechanics and ab-initio
THEORETICAL STUDY OF THE EFFECT OF WATER MOLECULE ADDITION ON THE CONFORMATION OF SUBSTITUTED DIBENZO-18-CROWN-6 ETHER IN ITS COMPLEXATION WITH Na<sup>+</sup> CATION USING SEMI EMPIRICAL METHOD MNDO/d
Authors: Pranowo Harno Dwi , Siregar Tuti Hartati , Mudasir Mudasir 
Published: January 2019

The effect of water molecule addition into modeling structure of complex of substituted dibenzo-18-crown-6 ether with metal ion Na+ was studied. The aim of this research is to find information about geometrical conformation of substituted DB18C6 and its selectivity to complex/coordinate metal ion Na+ in the presence of water molecule. In this research semi empirical method was used for calculation. To find the best conformation, trial and error experiments were conducted using semi empirical method available in HyperChem 6.0, finally MNDO/d method was selected. The result of geometry optimization showed that addition of water molecule improve the stability of the conformation of substituted DB18C6 and increase the selectivity of this compound to complex metal ion Na+. The presence of electron-withdrawing substituents decreased the binding energy while that of electron-donating one increase the binding energy (value of DE more negative). Cavity radii of DB18C6 in the presence of water molecule extended from 2.3 Å to 2.6 Å. This figure is almost similar to that of experimental data. Keywords: Crown ether, molecular modelling, semiempirical method
QUANTITATIVE STRUCTURE AND ACTIVITY RELATIONSHIP ANALYSIS OF 1,2,4-THIADIAZOLINE FUNGICIDES BASED ON MOLECULAR STRUCTURE CALCULATED BY AM1 METHOD
Authors: Mudasir Mudasir , Tahir Iqmal , Putri Ida Puji Astuti Maryono 
Published: January 2019

Quantitative structure-Activity relationship (QSAR) analysis of fungicides having 1,2,4-thiadiazoline structure based on theoretical molecular properties have been done. Calculation of the properties was conducted by semiempirical method AM1 and the activity of the compounds was taken from literature. Relationship analysis between fungicides activity (pEC50) and molecular properties was done using SPSS program. The QSAR analysis gave the best model as follows: pEC50 = 3.842 + (1.807x10-4) ET + (5.841x10-3) Eb - (5.689x10-2) DHf -0.770 log P + 1.144 a - 0.671 m + 9.568 GLOB - (5.54x10-2) MR. n=19 r=0.917 SE=0.216 Fcal/Ftable=2.459 PRESS=0.469. The best model obtained was then used to design and predict the fungicides activity of new compounds derived from 1,2,4-thiadiazoline. Keywords: QSAR, QSPR, fungicide, molecular structure, 1,2,4-thiadiazoline
MULTIFUNCTION OF LAYERED AND POROUS MATERIALS
Authors: Wijaya Karna 
Published: January 2019

In this review, two sort of materials i.e layered and porous materias which were studied by the author and coworkers intensively and extensively will be described. These materials generally can be classified into two groups, namely layered organic and inorganic materials and porous organic and inorganic materials. To the materials which classified in the first group, it will be discussed the syntheses, characterization and application of layered organic materials of imidazolium-dimesylamidate and of layered inorganic materials of montmorillonite. For the second group, as examples we will analogically describe the syntheses, characterization and application of 2,6-dimethylpyridinium-di(methanesulfonyl)amidate porous organic material and zeolite and pillared clay porous inorganic materials. Keywords: layered materials, porous materials, syntheses, characterization, application.
EXPLOITING A BENEFIT OF COCONUT MILK SKIM IN COCONUT OIL PROCESS AS NATA DE COCO SUBSTRATE
Authors: Setiaji Bambang , Setyopratiwi Ani , Cahyandaru Nahar 
Published: January 2019

A research to know influence of mixing concentration of coconut water and sucrose concentration to coconut milk skim as nata de coco substrate has been conducted. The variation was taken from mixing coconut water (0%, 25%, 35% and 50% and 100% as control) and the sucrose concentration (0.5%, 1%, 1.5% and 2%). Coconut milk skim boiled before used as substrat, yielded a coconut protein (blondo). The result of research showed that coconut milk skim can be used as nata de coco substrate with mixing coconut water and sucrose addition, mixing 50 % concentration coconut water representing optimum concentration. The content of crude fibre nata was yielded by higher concentration of sucrose, while mixing concentration coconut water do not influence crude fibre content. Keyword: Coconut milk skim, substrate, nata de coco
CHARACTERIZATION OF MODIFIED BENTONITE USING ALUMINUM POLYCATION
Authors: Haerudin Hery , Rinaldi Nino , Fisli Adel 
Published: January 2019

The modification of bentonite by pillarization using aluminum polycation type Keggin [Al13O4(OH)24(H2O)12]7+ has been carried out, by exchange of cation from interlayer with aluminum polycation. The amount of aluminum polycation, which was used for the pillaring of bentonite was varied, i.e. 5 mmol/gram, 10 mmol/gram, and 20 mmol/gram of bentonite. After drying, the pillared bentonite was calcined at 400 oC for 6 hour with temperature rate of 5 oC/min. The cationic exchange capacity (CEC) of starting bentonite was 98.3 meq/100 gram. The concentration ratio of Al/Si increased from 0.27 to 0.34 for pillared bentonite and of Ca/Si was decreased from 0.06 to 0.006 for pillared bentonite. The basal space for pillared bentonit increased significantly from 7.30 Å to about 18 Å . The measured specific surface area (by BET) of pillared bentonite was also increased significantly from 46 m2/g to about 162 m2/g. It was concluded that bentonite has been pillared by aluminum polication successfully. Keywords: aluminum polycation, bentonite
QSAR STUDY OF 1,10-PHENANTHROLINE DERIVATIVES AS THE ANTIMALARIAL COMPOUNDS USING ELECTRONIC DESCRIPTORS BASED ON SEMIEMPIRICAL AM1 CALCULATION
Authors: Mustofa Mustofa , Tahir Iqmal , Jumina Jumina 
Published: January 2019

Quantitative Structure-Activity Relationship (QSAR) analysis of 1,10-phenantroline analogs as antimalarial drug has been conducted using atomic net charges (q) as predictors of their activity. Data of predictors are obtained from computational chemistry method using semi-empirical molecular orbital AM1 calculation. Antimalarial activities are taken as the activity of the drugs against plasmodium falciparum (FcM29-Cameroun) strain and are presented as the value of ln(1/IC50) where IC50 is an effective concentration inhibiting 50 % of the parasite growth. The results show that there is correlation between antiplasmodial activity and electronic structure as represented by a linear function of activity versus atomic net charges of N1, C7, C10, C14 atoms on the 1,10-phenanthroline skeleton and is expressed by : log IC50 = -3,4398 - 14,9050 qN1 - 8,5589 qC10 - 14,7565 qC7 + 5,0457 qC11 The equation is significant at 95% level with statistical parameters : n = 13; r = 0,96275; r2 = 0,92689; SE = 0,61578 and F (4,8) = 25,3556. Keywords: antimalarial drug; 1,10-phenanthroline; QSAR; antiplasmodial activity.
EFFECT OF DIATOMEAOUS EARTH TREATMENT USING HYDROGEN CHLORIDE AND SULFURIC ACID ON KINETICS OF CADMIUM(II) ADSORPTION
Authors: Nuryono Nuryono , Narsito Narsito 
Published: January 2019

In this research, treatment of diatomaceous earth, Sangiran, Central Java using hydrogen chloride (HCl) and sulfuric acid (H2SO4) on kinetics of Cd(II) adsorption in aqueous solution has been carried out. The work was conducted by mixing an amount of grounded diatomaceous earth (200 mesh in size) with HCl or H2SO4 solution in various concentrations for two hours at temperature range of 100 - 150oC. The mixture was then filtered and washed with water until the filtrate pH is approximately 7 and then the residue was dried for four hours at a temperature of 70oC. The product was used as an adsorbent to adsorb Cd(II) in aqueous solution with various concentrations. The Cd(II) adsorbed was determined by analyzing the rest of Cd(II) in the solution using atomic absorption spectrophotometry. The effect of treatment was evaluated from kinetic parameter of adsorption rate constant calculated based on the simple kinetic model. Results showed that before equilibrium condition reached, adsorpstion of Cd(II) occurred through two steps, i.e. a step tends to follow a reaction of irreversible first order (step I) followed by reaction of reversible first order (step II). Treatment with acids, either hydrogen chloride or sulfuric acid, decreased adsorption rate constant for the step I from 15.2/min to a range of 6.4 - 9.4/min. However, increasing concentration of acid (in a range of concentration investigated) did not give significant and constant change of adsorption rate constant. For step II process, adsorption involved physical interaction with the sufficient low adsorption energy (in a range of 311.3 - 1001 J/mol). Keywords: adsorption, cdmium, diatomaceous earth, kinetics.
THERMAL EFFECT OF COCONUT CREAMS ABILITY TO ADSORB CALCIUM(II)
Authors: Tahir Fatmawati , Setyopratiwi Ani , Sudiono Sri 
Published: January 2019

Study of thermal effect of coconut cream's ability to adsorb Ca (II) has been done at various temperatures of 49 oC, 59 oC and 80 oC. The adsorption study was performed to check capacity, energy and rate of adsorption by varying the number of initial concentration of CaCl2 bounded on coconut protein. This research was also done to determine number of Ca (II) in the coconut protein using the salt addition and elicits reaction methods. The result showed that adsorption ability tends to increased with the increase of temperature). Coconut cream heated at 59 oC adsorb Ca(II) with the highest adsorption capacity of 3.98 mg/g and K = 3.48x104 mol-1. The salt addition method on the coconut cream gives more Ca (II) than elicit reaction method. The first method gives 0.01137 mol/L and the second was 0.02845 mol/L. Based on the energy of adsorption, cream without heating had 20.59 kJ/mol as a physical adsorption and heating effect at temperatures 49 oC, 59 oC and 80 oC had 24.95; 28.87 and 24.87 kJ/mol respectively as a chemical adsoprtion with the rate of adsorptions of 0,0054; 0,0510 dan 0,3. 10-4 minute-1, respectively. Keywords: coconut cream, adsorption, thermal effect.
THE SYNTHESIS OF Cr<sub>2</sub>O<sub>3</sub>-PILLARED MONTMORILLONITE (CrPM) AND ITS USAGE FOR HOST MATERIAL OF p-NITROANILINE
Authors: Wijaya Karna , Tahir Iqmal , Baikuni Ahmad 
Published: January 2019

The synthesis of Cr2O3-pillared montmorillonite (CrPM) and its usage for host material of p-nitroaniline have been conducted. The Cr2O3-pillared montmorillonite clays was prepared by a direct ion exchange method. First, the polyhydroxychromium as a pillaring spesies was intercalated into the interlayer region of the montmorillonite clays (purified clay in the monocation form), result in a montmorillonite-polyoxychromium intercalation compound. The precursors/pillaring spesies was not stable, hence it must be stabilized by calcination in order to transform the polyoxychromium via dehydration and dehydroxylation processes into Cr2O3. This oxide constituts the so-called pillar that prop the clay layers apart to a relatively large distance. The Cr2O3-pillared clays as a host material was added into ethanol solution saturated with p-nitroaniline, and mixture was stirred for 24 h at room temperature. The Na-montmorillonite, Cr2O3-pillared clay and p-nitroaniline-Cr2O3-pillared clay (pNA-CrPM) were characterized by X-Ray Diffraction (XRD), Gas Sorption Analysis, Infrared Spectroscopy (FTIR) and Activated Neutron Analysis (ANA) methods. The result of research showed that basal spacing (d001) of Cr2O3-pillared montmorillonite (CrPM) was 18,55 Å, meanwhile the basal spacing of the hydrated Na-montmorillonite was 14,43 Å. The specific surface area of the Cr2O3-pillared montmorillonite was 174,308 m2/g, whereas p-nitroaniline-Cr2O3-pillared clay (pNA-CrPM) was 133,331641 m2/g. This fact indicated that p-nitroaniline has been included into the pore of the Cr2O3-pillared clay. Keyword: montmorillonite, pillared-clay, ion exchange, intercalate.