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Rapid development of biodiesel production in Indonesia increases by-product of glycerol availability. As an effect, glycerol is in abundant stock and its market value decreases. This study has been aimed at valorizing glycerol market value by converting it into mono-alcohols, in particular ethanol. Catalytic conversion has been attempted by examining several nickel based catalyst performances on glycerol transformation. The catalysts were developed by impregnating nickel metal salts precursor on activated carbon, silica, magnesium oxide and alumina. Hydrogenolysis was selected to carry out the reaction, conducted at 2 MPa and 473 – 573 K. Analysis of the catalyst performance showed that the highest conversion of glycerol can be obtained with the use of Ni/MgO catalyst, in which 81% conversion could be achieved. The highest yield of ethanol: 1.1%, was recorded when alumina catalyst was applied in the reaction. [ABSTRACT FROM AUTHOR]

Water scarcity has been a severe threat to our society. Indonesia is a tropical country where solar energy is abundant and sustainable because it is available the entire year. In this work, we proposed a bilayer solar steam generation (SSG) system derived from coir fiber biomass as freshwater production from sea water. The proposed bilayer SSG system consisted of cellulose aerogel derived from coir fiber as the support for black ink that serves as photothermal material to convert sunlight into heat to evaporate water. The cellulose aerogel was synthesized from coir fiber using an aqueous urea-ammonia system of the mechanically and chemically pretreated coir fibers. The cellulose aerogel had excellent capillary effect for water with a water rise of approximately 0.63 cm/min. In addition, it also had low thermal conductivity, about 0.41 W/m·K. The water evaporation rate of the SSG system using the cellulose aerogel was relatively high that reached approximately 1.1 L/m2·h under 1 sun irradiation. It appears that cellulose aerogel with excellent capillary effect and low thermal conductivity can function well as both a water transporter and an insulator. The carbon black and cellulose aerogel appear promising as a sustainable photothermal, and substrate material used for solar-driven water purification to supply clean water from seawater. [ABSTRACT FROM AUTHOR]

Capsule is a material used to facilitate drugs for an improved protection and enhanced consumers compliance. Due to several reasons such as related with consumers believe and other personal preferences, alternative materials for capsule manufacturing have been investigated. This research uses carrageenan from seaweed utilizing Indonesia marine resources. The objective of this research is to investigate potency of carrageenan to substitute gelatin as alternative material of hard capsule. Carrageenan was mixed with starch of cassava, using glycerol as plasticizer in various compositions at 70-80℃C. As much as 2 g of sodium tri-polyphosphate (STPP) was added as crosslinker agent. The suspensions were molded by using stainless steel dipping pen. Sample analysis showed produced hard capsule was in the range weight of 87 to 105 mg, and dissolution time of minute, which informs potential of this study for further developments. [ABSTRACT FROM AUTHOR]

In this study, ZnO-Ag nanocomposites with different Ag loadings have been successfully synthesized by spray pyrolysis using nitrogen as a carrier gas. The Ag loading with various concentrations from 0 to 10 %wt was doped to the ZnO particles. The performance of products, ZnO-Ag nanocomposites, was subsequently tested by measuring the photocatalytic degradation of organic waste from the textile dye. Morphology, crystallite size and crystalline phase, surface area and functional group of hydroxyl of the produced nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and Fourier Transform Infrared Spectroscopy (FTIR), respectively. SEM images indicated that the average particle size of the nanocomposite measured by ImageJ software increased with increasing Ag loading. The average size of nanocomposite with Ag loading at 0, 1, 5, and 10 %wt were 784, 850, 856 and 954 nm, respectively. The XRD results detected the existence of Ag in ZnO-Ag nanocomposite. However, the addition of Ag in the nanocomposite did not alter the crystallite size significantly, where the crystallite size was found approximately around 18 to 57 nm. Moreover, BET analysis showed the increase of specific surface area with increasing Ag content in exception for Ag content at 5 %wt. Finally, ultraviolet (UV) light was used as an irradiation source to evaluate the performance of photocatalytic degradation of textile-dye-waste from the textile industry in Gresik-Indonesia. The results showed that Ag loading at 5 %wt produced the highest degradation efficiency among the other concentrations including the pristine ZnO. This research resulted in a simple and effective route for fabricating ZnO-Ag nanocomposite; therefore, it can be considered as a potential candidate for the direct application in degradation of textile-dye-waste. [ABSTRACT FROM AUTHOR]

Organic waste derived from the textile dye of textile industry in Gresik is toxic and dangerous to humans and the ecosystem. The waste from textile dye must be handled properly before its disposal to the river. Photodegradation of the organic pollutant by catalyst derived from semiconductor materials is one of the promising methods. ZnO is widely used as photocatalyst because of its wide bandgap energy (3.4 eV) and large free excitation binding energy. Furthermore, the addition of ZnO with noble metals can enhance the photocatalytic performance. In this study, ZnO-Ag nanocomposites have been successfully synthesized via a one-step process using spray pyrolysis method. Pure oxygen was used as the carrier gas. The effect of Ag content ranging from 0 to 10 %wt on the photocatalytic performance was studied. Zinc acetate dihydrate 0.1 M and silver nitrate were used as precursors to produce ZnO-Ag nanocomposite inside the tubular reactor. The produced nanocomposites were analyzed by Scanning Electron Microscopy (SEM) and X-ray Diffractometry (XRD). SEM observation showed that the morphology of the produced nanocomposite was sphere-like structures with interwoven nanoplate particles with some aggregation. The different crystallite size was also observed by XRD analyses. Based on the XRD patterns, the existence of Ag in the nanocomposite was detected when the Ag concentration was greater or equal to 5 %wt. Brunauer–Emmett–Teller (BET) was also performed to estimate the specific surface area of the nanocomposites, where the increase of Ag content is proportional to the specific surface area. Fourier Transform Infrared Spectroscopy (FTIR) was conducted to better understand the functional groups in the nanocomposites and dye pollutants. Finally, the photocatalytic activity of ZnO-Ag was evaluated by the degradation of the dye pollutants from textile home industry at Kabupaten Gresik under UV light irradiation. The photocatalytic activity of the ZnO-Ag was higher than that of pristine ZnO, where the maximum photodegradation was obtained at Ag content as much as 5 %wt with the degradation efficiency that reached 23%. [ABSTRACT FROM AUTHOR]

Sugarcane bagasse is generated in large quantities during the processing of sugarcane in the sugarcane industry. For a country like Indonesia with its vast agricultural residues such as sugarcane bagasse, it is imperative to have an efficient power generation system utilizing the residues. Gasification of sugarcane bagasse is a carbon dioxide emission neutral source of energy and also has the advantage of syngas production. Syngas composition varies based on gasification technology used and can be adapted to specific applications. Among the gasification technologies that are widely used are downdraft and fludized beds. The objective of this work, therefore, is to provide a comparison between downdraft and fluidized bed gasification based on the production capacity of syngas using Aspen Plus simulation. The sugarcane bagasse used in the simulation was obtained from sugar factory PG Gempolkrep Mojokerto, East Java. The results show that at the ratio of steam to biomass equal 1.0, H2 decreases with increasing temperature both with downdraft and fluidized bed gasification. CO increases with increasing temperature in the downdraft gasification, but decreases with increasing temperature in fluidized bed gasification. At temperature 750°C, H2 increases with increasing the ratio of steam to biomass, but decreases with increasing the ratio of steam to biomass. Meanwhile, CO decreases with increasing the ratio of steam to biomass for both downdraft and fluidized bed gasification. From the aspect of CO2 produced, it can be concluded that fluidized bed gasification is more environmentally friendly than downdraft gasification. [ABSTRACT FROM AUTHOR]

Biogas is produced when certain kinds of bacteria digest organic substances in an anaerobic environment. Typical raw biogas consists of about two thirds of methane (CH4) and one third of carbon dioxide (CO2). Even though raw biogas can be used directly to generate power, but the large volume of CO2 reduces the heating value of the gas, increasing compression and transportation costs and limiting economic feasibility. In this work, the raw biogas from small scale digester was upgraded by counter-current contacting it with a saturated Ca(OH)2 solution in a bubble column contactor to capture CO2. The bubble column comprises of a cylindrical column 7.3 cm in diameter and 100 cm high and is equipped with a perforated plate gas distributor. The CO2 content in upgraded biogas exit from top bubble column was sampled and measured using Gas Chromatography. The effect of ratio raw biogas to Ca(OH)2 solution flow rate with different liquid height and concentration of Ca(OH)2 solution on CO2 removal were investigated. The results showed that CO2 removal depends on the superficial velocity of the biogas, the flow rate of the Ca(OH)2 solution, the liquid height. The absorption of CO2 increases as the absorbent flow rate increases and decreases as the gas flow rate increases. The use of Ca(OH)2 above the solubility shown in the continuous process showed higher absorption of CO2. However, the increasing CO2 absorption is not significant with increasing Ca(OH)2 concentration. The highest absorption of CO2 obtained in the continuous process is 79.34 %. [ABSTRACT FROM AUTHOR]

ZnO-SiO2 nanocomposite particles were prepared by sonochemical method under continuous ultrasound irradiation for an hour. Zinc nitrate and sodium silicate were used as zinc oxide and silica sources, respectively. Silica concentration was varied to investigate the effect of silica on the characteristics of the generated composite particles and they were also compared to ZnO particles. Morphology, crystallinity, chemical bonding analysis, photoluminescence spectra, and photocatalytic activity were characterized by scanning electron microscopy (SEM), X-Ray diffraction, Fourier Transform Infrared (FTIR), luminescence spectrophotometer, and UV-Vis spectrophotometer, respectively. Nanorod structures were observed for pure ZnO, ZnO-SiO2 particles with 250 ppm and 750 ppm silica addition during synthesis. Spherical agglomerated particles were found for particle with 0.1 M silica addition. The crystalline size and photocalytic activity decreased with the silica addition. A strongest chemical bonding for ZnO and SiO2 was also observed for particle with 0.1 M silica addition based on FTIR spectra. However, the highest photoluminescence emission by excitation wavelength at 250 nm, was observed for ZnO-SiO2 particles with 750 ppm silica addition with emission peak at 515 nm wavelength. [ABSTRACT FROM AUTHOR]

Antioxidant compounds from mangosteen pericarps have been extracted with low-transition-temperature mixture (LTTM) assisted hydrothermal method. Extracted antioxidant compounds were determined as xanthone and total phenolic compounds. The effects of temperature, concentration of LTTM, and sonication pretreatment on the recovery of xanthone and total phenolic compounds were investigated. Extraction were carried out in a batch extractor at various temperatures (120 - 160°C), concentrations of LTTM (0.1 - 0.3 mg/mL), and sonication pretreatments (0 - 10 min). LTTM used for extraction was consisted of citric acid as hydrogen bond donor and alanine as hydrogen bond acceptor. Xanthone and total phenolic compounds were analyzed by spectrophotometer. In order to determine the effect of extraction condition on the antioxidant efficiency of the extract, the antioxidant efficiency of extract were analyzed by DPPH assay method. Based on the result, the recovery of xanthone increased as increasing temperature and concentration of LTTM. Inversely, the recovery of total phenolic compounds decreased as increasing temperature. The sonication pretreatment had significantly effect on the recovery of both xanthone and total phenolic compounds, however the optimum condition of sonication pretreatment was at 5 min. The antioxidant efficiency of the extract was affected by the extraction condition, and the highest antioxidant efficiency was 1.395 obtained at temperature of 120°C, LTTM concentration of 0.3 mg/mL, and sonication time of 5 min. [ABSTRACT FROM AUTHOR]

Scralatina or Dengue Fever is a kind of fever caused by serotype virus which Flavivirus genus and be known as Dengue Virus. Dengue Fever caused by Aedes Aegipty Mosquito bites who infected by a dengue virus. The study was conducted in 151 villages in Bandung. Health Analysts believes that there are two factors that affect the dengue cases, Internal factor (individual) and external factor (environment). The data who used in this research is hierarchical data. The method is used for hierarchical data modelling is multilevel method. Which is, the level 1 is village and level 2 is sub-district. According exploration data analysis, the suitable Multilevel Method is Random Intercept Model. Penalized Quasi Likelihood (PQL) approach on multilevel Poisson is a proper analysis to determine factors that affecting dengue cases in the city of Bandung. Clean and Healthy Behavior factor from the village level have an effect on the number of cases of dengue fever in the city of Bandung. Factor from the sub-district level has no effect. [ABSTRACT FROM AUTHOR]

So far, most of the data published by Statistics Indonesia (BPS) as data providers for national statistics are still limited to the district level. Less sufficient sample size for smaller area levels to make the measurement of poverty indicators with direct estimation produced high standard error. Therefore, the analysis based on it is unreliable. To solve this problem, the estimation method which can provide a better accuracy by combining survey data and other auxiliary data is required. One method often used for the estimation is the Small Area Estimation (SAE). There are many methods used in SAE, one of them is Empirical Best Linear Unbiased Prediction (EBLUP). EBLUP method of maximum likelihood (ML) procedures does not consider the loss of degrees of freedom due to estimating β with .... This drawback motivates the use of the restricted maximum likelihood (REML) procedure. This paper proposed EBLUP with REML procedure for estimating poverty indicators by modeling the average of household expenditures per capita and implemented bootstrap procedure to calculate MSE (Mean Square Error) to compare the accuracy EBLUP method with the direct estimation method. Results show that EBLUP method reduced MSE in small area estimation. [ABSTRACT FROM AUTHOR]

This study aims to show changes in the performance of combustion using pulse combustion at specified intervals using simulation. Simulations is performed using Computational Fluid Dynamics analysis (CFD) software Ansys Fluent 15.0. Analysis used 2D illustration axisymmetric with k-ε turbulence models. Propane was selected as fuel at a flow rate of 15 L/min. Air with flow rate of 375 L/min is used as oxidizer. To investigate the advantages of using pulse combustion, the simulated pulse combustion is compared to normal combustion without a pulse. This is done by displaying descriptions of the phenomenon, mechanisms and results output gas combustor. From the analysis of simulation results showed that in 1 minute burning time, burning fuel without requiring pulse as much as 15 L while the pulse combustion requires half of the fuel which is 12.5 L. However, the higher average of temperature was generated by pulse combustion and the amounts of unburned fuel that comes out of the combustor less than without the use of pulse combustion. So, it can be concluded that the pulse combustion is more efficient than combustion without a pulse. [ABSTRACT FROM AUTHOR]

Flame assisted spray dryer are widely uses for large-scale production of nanoparticles because of it ability. Numerical approach is needed to predict combustion and particles production in scale up and optimization process due to difficulty in experimental observation and relatively high cost. Computational Fluid Dynamics (CFD) can provide the momentum, energy and mass transfer, so that CFD more efficient than experiment due to time and cost. Here, two turbulence models, k-ε and Large Eddy Simulation were compared and applied in flame assisted spray dryer system. The energy sources for particle drying was obtained from combustion between LPG as fuel and air as oxidizer and carrier gas that modelled by non-premixed combustion in simulation. Silica particles was used to particle modelling from sol silica solution precursor. From the several comparison result, i.e. flame contour, temperature distribution and particle size distribution, Large Eddy Simulation turbulence model can provide the closest data to the experimental result. [ABSTRACT FROM AUTHOR]

The multiphase polymerization reaction of the silica sol formation produced from silicic acid and potassium hydroxide solutions in laboratory scale agitated tank was studied. The reactor is equipped with four segmental baffle and top entering impeller. The inside diameter of reactor is 9 cm, the baffle width is 0.9 cm, and the impeller position is 3 cm from tank bottom. The diameter of standard six blades Rushton and three blades marine propeller impellers are 5 cm. The silicic acid solution was made from 0.2 volume fraction of water glass (sodium silicate) solution in which the sodium ion was exchanged by hydrogen ion from cation resin. The reactor initially filled with 286 ml silicic acid solution was operated in semi batch mode and the temperature was kept constant in 60 °C. The 3 ml/minute of 1 M potassium hydroxide solution was added into stirred tank and the solution was stirred. The impeller rotational speed was varied from 100 until 700 rpm. This titration was stopped if the solution in stirred tank had reached the pH of 10-11. The morphology of the silica particles in the silica sol product was analyzed by Scanning Electron Microscope (SEM). The size of silica particles in silica sol was measured based on the SEM image. The silica particle obtained in this research was amorphous particle and the shape was roughly cylinder. The flow field generated by different impeller gave significant effect on particle size and shape. The smallest geometric mean of length and diameter of particle (4.92 µm and 2.42 µm, respectively) was generated in reactor with marine propeller at 600 rpm. The reactor with Rushton impeller produced particle which the geometric mean of length and diameter of particle was 4.85 µm and 2.36 µm, respectively, at 150 rpm. [ABSTRACT FROM AUTHOR]

Nanostructured ZnO was synthesized by a sonochemical reaction. Ultrasonic irradiation were set up in continuous, pulse in 3 seconds on and a second off (on:off = 3:1), and pulse in 2 seconds on and a second off (on:off = 2:1) wave modes for 1.5 hours. The characteristics of particles generated by these modes such as morphology, crystallinity, FTIR, photoluminescence, and photocatalytic activity to degrade methylene blue were compared. Zinc nitrate and ammonia water-based solutions were selected as chemicals without the addition of other surfactants. The morphology of the generated ZnO particles could be tuned from flower-like, needle- or hairy-like, and spherical structures by changing the mode of ultrasonic irradiation from continuous, on:off=3:1, and on:off=2:1 modes, respectively. The generated particles indicated that a wurtzite structure of ZnO in a hexagonal phase was formed. The crystalline sizes of particles generated in continuous, on:off=3:1, and on:off=2:1 modes were 28, 27, 24 nm. A similar position of reduction peak of FTIR in all samples indicated that no differences in particles chemical bonding characteristics. Photoluminescence intensity was also decreased with changes the wave mode from continuous to pulse. Photocatalytic activity was also evaluated resulting in particles synthesized by continuous mode had the highest methylene blue degradation degree following by on:off=3:1, and on:off=2:1 modes. [ABSTRACT FROM AUTHOR]

In this study the effect of fuel rate and annealing on particle formation of LiFePO4 as battery cathode using flame spray pyrolysis method was investigated numerically and experimentally. Numerical study was done using ANSYS FLUENT program. In experimentally, LiFePO4 was synthesized from inorganic aqueous solution followed by annealing. LPG was used as fuel and air was used as oxidizer and carrier gas. Annealing process attempted in inert atmosphere at 700°C for 240 min. Numerical result showed that the increase of fuel rate caused the increase of flame temperature. Microscopic observation using Scanning Electron Microscopy (SEM) revealed that all particles have sphere and polydisperse. Increasing fuel rate caused decreasing particle size and increasing particles crystallinity. This phenomenon attributed to the flame temperature. However, all produced particles still have more amorphous phase. Therefore, annealing needed to increase particles crystallinity. Fourier Transform Infrared (FTIR) analysis showed that all particles have PO4 function group. Increasing fuel rate led to the increase of infrared spectrum absorption corresponding to the increase of particles crystallinity. This result indicated that phosphate group vibrated easily in crystalline phase. From Electrochemical Impedance Spectroscopy (EIS) analysis, annealing can cause the increase of Li+ diffusivity. The diffusivity coefficient of without and with annealing particles were 6.84399×10-10 and 8.59888×10-10 cm2 s-1, respectively. [ABSTRACT FROM AUTHOR]

Zirconium oxide (zirconia, ZrO2) is the most common material used for electrolyte of solid oxide fuel cells (SOFCs). Zirconia has attracted attention for applications in optical coatings, buffer layers for growing superconductors, thermal-shield, corrosion resistant coatings, ionic conductors, and oxygen sensors, and for potential applications including transparent optical devices and electrochemical capacitor electrodes, fuel cells, catalysts, and advanced ceramics. In this work, zirconia particles were synthesized from ZrCl4 precursor with hydrothermal treatment in a batch reactor. Hydrothermal treatment may allow obtaining nanoparticles and sintered materials with controlled chemical and structural characteristics. Hydrothermal treatment was carried out at temperatures of 150 - 200°C with precursor concentration of 0.1 - 0.5 M. Zirconia particles obtained from this treatment were analyzed by using SEM, PSD and XRD to characterize the morphology, particle size distribution, and crystallinity, respectively. Based on the analysis, the size of zirconia particles were around 200 nm and it became smaller with decreasing precursor concentration. The increasing temperature caused the particles formed having uniform size. Zirconia particles formed by hydrothermal treatment were monoclinic, tetragonal and cubic crystal. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA) or (Ca10(PO4)6(OH)2 has been widely used in orthopedics and dental applications for human bone implant and teeth filler due to their biocompatibility and osteoconductive properties. Fine to nanoparticles of HA with appropriate stoichiometry and purity are preferred because they enhance densification and bioactive properties. Here, we reported the synthesis of hydroxyapatite particles in a diffusion flame reactor. LPG mainly consisting of butane and propane was used as fuel and compressed air was used as oxidizer and carrier gas. The effects of urea adding into precursor on morphology and crystallinity of the generated particles were investigated. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to observe particles morphology and crystallinity, respectively. Purity of the generated particles was analyzed quantitatively from XRD pattern using Rietveld method. Spherical shape of particles morphology was obtained for particles synthesized without urea added into precursor. Increasing fuel flow rate and urea concentration led to further disintegration of the generated particles. Nano sized particles were generated using fuel flow rate of 1 L/min and 30 w% concentration of urea added into precursor. However, increasing urea concentration led to the increase of tricalcium phosphate as a further reaction of hydroxyapatite for flame generated by using LPG as fuel of 1 L/min. [ABSTRACT FROM AUTHOR]