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Solid electrolyte is the essential part in all-solid-state battery (ASSB), in which the sintering step is vital to get a dense and high ionic conductivity. However, Li-loss frequently occurs at a high temperature, causing ionic conductivity to drop. This research investigated a dry-cold sintering process (dry-CSP) to Ta doped-LLZO (LLZTO), in which the LLZTO powder was pressed by cold isostatic pressing (CIP) at 40 MPa without solvent addition and then heated at 300oC for 2h. XRD analysis found that LLZTO300C40P remains crystallized in a single cubic with ionic conductivity of (3.02 0.53) x 10-5 Scm-1, which is higher than another result in Al doped-LLZO by CSP uniaxial pressing and with moistened-solvent (wet-CSP). The feasibility was tested by preparing a coin cell with a LiCoO2 cathode and Li metal anode. Cyclic voltammogram of the LCO-LLZTO300C40P-Li ASSB provides a high current density representing a higher electrochemical reaction rate inside the full cell. The battery ran well with an initial charging capacity of 88 mAh/g, and a discharge capacity of 50 mAh/g, providing 56.8 % Coulombic Efficiency. An interface engineering between electrode-solid electrolyte is essential to develop the ASSB performance.

The KCaF3 perovskite catalyst was successfully synthesized by reacting limestone (natural-CaCO3) with potassium fluoride (KF). The synthesis of the KCaF3 catalyst was conducted with several variations in the mole ratio of CaCO3 to KF (1:1, 1:2, and 1:3). The research results showed that the addition of KF can affect the characteristics of the catalyst. The optimal catalyst is the KCaF3 catalyst with a mole ratio variation of 1:3. X-ray diffractometer analysis revealed that the highest KCaF3 phase composition reached 74.05%, while thermogravimetric analysis indicated a CaCO3 concentration of 34.50%. Surface Area Analyzer analysis shows that KCaF3 has the largest surface area, which is 187.1 m2/g. This catalyst efficiently facilitated the transesterification of palm oil, yielding 93.4% biodiesel.

ABSTRACT. Bio-oil is a renewable energy source with high oxygen levels, and anisole is a chemical widely employed in research to represent it. Catalytic hydrodeoxygenation (HDO) reduces the oxygen content. A catalyst known as nickel-modified HZSM-5 has shown promising results for HDO. Meanwhile, catalyst efficiency depends on the Ni/HZSM-5 ratio. So, this study aims to determine how the Ni/HZSM-5 ratio influences the catalyst's properties, activity, and selectivity in anisole HDO. The Ni/HZSM-5 catalyst was made using the wet impregnation method with various ratios of Ni/HZSM-5. The catalysts were analyzed for their morphology using scanning electron microscopy-energy-dispersive X-ray (SEM-EDX). The diffraction patterns were studied using X-ray diffraction (XRD). Surface area and porosity were determined through gas sorption analysis (GSA). Then, the acidity strength was evaluated via temperature-programmed ammonia desorption (NH3-TPD). The characterization results show Ni was successfully impregnated and distributed evenly in HZSM-5 without changing the primary structure. Adding Ni metal to HZSM-5 increases the surface area of the catalyst but reduces its acid strength. The catalytic performance of the catalysts was then evaluated in a flow reactor at 400 °C, using 15 mL/min H2 gas. The liquid products of the reaction were analyzed using gas chromatography-mass spectroscopy (GC-MS). The results of the catalytic performance show that Ni4.5/HZSM-5 has the highest catalytic activity in anisole conversion. At the same time, Ni6.4/HZSM-5 shows the highest selectivity towards benzene-toluene-xylene (BTX). Keywords: Hydrodeoxygenation, nickel, anisole, heterogeneous catalyst, acidity.

Novel bio-based electrode polyurethane (PU) fabricated using various conducting materials such as graphene oxide (GO), gold (Au), and carbon nanotube (CNT) as the primary source of a charge carrier. Initially, PU/GO, PU/Au, and PU/CNT polymers were synthesized using a pre-polymerization approach. Therefore, the application of conductive materials modifies and increases the conductivity of PU. The connection between PU and the conductive materials (GO, Au, and CNT) was identified using Fourier transform infrared (FTIR), whereby some important functional groups obtained in this spectrum investigation, such as the presence of amide (-NH) and carbonyl urethane(-C = O), following the absence of diisocyanate groups (-NCO) revealed the synthesis was satisfactory. The glass transition temperatures (Tg) of PU/GO, PU/Au, and PU/CNT were analyzed using differential scanning calorimetry (DSC). In contrast, the mass loss during the heat treatment was observed using thermogravimetric analysis (TGA). Furthermore, thermal studies have proven that PU/GO has higher thermal stability compared to PU/Au and PU/CNT. The field emission scanning electron microscopy (FESEM) presents satisfactory results between PU composites and pure PU. The conductivity of PU and PU composites was examined using electrochemical impedance spectroscopy (EIS) and showed that PU/GO has a better electrical conductivity (σ) at 3.68 × 10−3 S cm−1.

This research aimed to produce a screen-printed carbon electrode (SPCE) from an activated coconut shell carbon. As a raw material, coconut shell char provides renewability and is abundantly available in the market. Meanwhile, SPCE offers a simple electroanalytical electrode because the working, counter, and reference electrodes are in one piece. The coconut shell carbon was activated by steam at 700 oC for 1h, producing AC700 that was then characterized to ensure the result by following per under carbon as the main component, the phases, crystal structure, surface area, morphology, and elemental content. The result showed that the surface area of AC700 is 816 m2/g, and the surface structure is porous, as identified by SEM images. Impedance analysis followed by data fitting and conductivity calculation found a high conductivity of 8.68 x 10-2 Scm‑1. The produced-SPCE or SPAC700 was modified by ferrocene at various compositions of 10%; 20%; and 30% of mass. The SPAC700-Fc30 provided the best performance for lead analysis with a detection limit of 0.35 mM, a quantitation limit of 1.17 mM, and good reproducibility with a Repeatability Coefficient (RC) of 0.022. SPAC700-Fc30 showed good lead ions detection despite under 10% Cu2+ and 10% Co2+ interferences. The result confirmed the potential use of coconut shell char as the raw material for SPCE production.

This research studied kinetics of thermal degradation of polystyrene (PS), and sulfonated polustyrene (sPS) which were synthesized from styrofoam waste. The thermal study was conducted by thermogravimetric analysis (TGA) at various heating rate of 10, 15, 20 and 25 dpm. The kinetics parameters were determined by Coats Redfern (CR), Friedman (FM), Kissinger-Akahira-Sunose (KAS) and Ozawa-Flynn-Wall (OFW) models. TGA result found that PS has range thermal stability of 274 – 415 oC, but sPS has range thermal stability of 175 – 582 oC. Kinetic study to PS shows that the activation energy increases by the increasing of fraction conversion for all kinetics parameters with a regression value close to 1. While in sPS, the CR method shows an increase in activation energy value with an increasing fraction convertion. On the other hand, CR-FM-KAS and OFM methods obtained an increase in activation energy, then decreased at the fraction convertion above 0.6, and received negative activation energy. The kinetics model successfully explains the degradation of PS and sPS. In addition, the high thermal stability of sPS from styrofoam waste shows that this material has good potential as polymer electrolyte materials.

This research aims to study the Al-Y dopant to Lithium Lanthanum Zirconate (LLZO) to the characteristics and electrical properties of the LLZO as solid electrolyte. The synthesis was conducted through solid state reaction with Al2O3 and Y2O3 as dopant precursors. X-ray diffraction analysis along with Le Bail refinement was done to understand their structure, and phase content inside. The result found that Al and Y doping increased the cubic phase from 49.58% to 84.91%. The Al-Y doped-LLZO (LLZAYO) powder was then treated by a various cold isostatic pressing, CIP of 0, 20, 30, and 40 MPa to understand the effect of cold isostatic pressure to the ionic conductivity and solid electrolyte performance of the material even without heat sintering treatment. The result found that the green pellet of LLZAYO) which was isostatically pressed by 40 MPa at room temperature provides (9.06 ±0.26) x10-6 Scm-1, about 8 times higher than the LLZO without doping, i.e., (1.25 ±0.01) x 10-6 Scm-1. All solid-state battery with the prepare LLZAYO CIP 40 as solid electrolyte shows reversible reaction of Li/Li+ redox accompanied with Al/Al3+ redox. The Al/Al3+ reaction seems to decrease the electronic resistance between LCO-LLZAYO CIP40-Li which causes the full cell performance to decrease. The initial specific charging capacity is 82 mAh/g, and the initial discharge was 83 mAh/g, confirming 101 % of Coulombic efficiency. The discharge capacity drops to 46 mAh/g at second cycle, leading to a decrease in Coulombic efficiency to 56 %.

Defects in graphene alter its structure, electrical characteristics, and interaction with K+ ions. The related characteristics of divacancy defect graphene and N, S codoped divacancy graphene were effectively explored using the DFTB technique. Divacancy is essential for the band gap opening. The dopants considerably enhance the density of state (DOS) intensity and alter the graphene-character bands. The depletion of density caused by the dopant is seen on the charge density isosurface. Because the charge of the K+ ion is balanced by the dopant, the ion prefers to be adsorbed on divacancy graphene with dopants.

A study on the effect of S doping and K+ adsorption to the electronic properties of graphene has been conducted by DFTB (Density Functional Tight Binding) calculation. The supercell of 40 x 40 x 1 configured from the 4x4x1 unit cell of graphene was optimized. The calculation shows that the Fermi level of graphene shifted from -4.67 eV into -3.57 eV after S doping. In addition, the S presence caused the formation of gap within the Dirac K of valence band and conduction band. Meanwhile, K+ charge distribution was dominantly occurred within the S-graphene than the graphene.

In this research, a cyclic voltammetry (CV) method was applied to intercalate Na+ into an FePO4/Al substrate to produce NaFePO4/Al as a potential cathode material. The sodiation was conducted directly to FePO4 instead of applying delithiation to LiFePO4 followed by sodiation, as was done in previous research. CV was conducted within a potential window of 2.0–4.0 V using a scan rate of 0.05 mVs-1. The result was compared to LiFePO4/Al treated with a similar method. The various scan rate was then applied to understand its effect on the electrochemical activity recorded in the voltammogram and its impedance profile. The results show that the CV product of FePO4/Al (NFP(A)) was crystallized in an orthorhombic olivine NaFePO4, as a result of Le Bail refinement. Orthorhombic Na0.7FePO4, trigonal FePO4, and monoclinic FePO4 were presented as secondary phases. Meanwhile, the CV product of LiFePO4/Al (NFP(B)) was also crystallized in olivine NaFePO4 and possessed secondary phases similar to NFP(A) with an additional Fe2O3 phase. NFP(A) showed two significant peaks at 2.442 V and 3.534 V, confirming sodiation/de-sodiation and Fe3+/Fe2+ activity, respectively. Meanwhile, NFP(B) showed two peaks at 3.183 V and 3.04 V, corresponding to de-lithiation and sodiation, respectively. The Nyquist plots of both materials show a similar profile, with the impedance value of NFP(A) being lower than that of NFP(B). This confirms that the CV treatment of FePO4/Al is more facile than the treatment of the LiFePO4 layer, while also producing a cathode with higher electrical conductivity. Scan rate reduction to 0.04 mVs-1 produced a much lower impedance value, confirming higher electrical conductivity.

Desiccant dehumidification systems can be utilized for decoupling moisture removal duty from the conventional mechanical vapor compression systems. Dehumidification using desiccant dehumidifiers is expected to exhibit a better energy efficiency. However, the high energy needed in the regeneration process limits its applicability. To realize the full potential of this technology, it is necessary to develop materials that can be regenerated using heat sources under 70 °C. In this study, activated carbons (ACs) derived from waste biomass were developed as desiccant materials. The ability of activated carbon (AC) to remove the moisture was controlled by carefully preparing the material to achieve the right operation window for optimum moisture sorption processes. The porous and surface characteristics of the newly-prepared AC were analyzed and compared with those of silica gel. The adsorption isotherm measurements were conducted, and the data were fitted with Henry–Sips and Do–Do isotherm models. The current ACs exhibit an excellent water adsorption capacity (up to 0.41 g/g). The efficacy of the ACs for dehumidification applications was assessed using the weather data from several regions of Indonesia, from North Sumatera to Papua. The results revealed that under the studied conditions, the new desiccant material showed a better dehumidification capacity than silica gel. Moreover, the reported AC can be regenerated using temperatures as low as 40 °C, which is readily available from waste heat, including the heat rejection from the condenser of an air-conditioning unit.

Li7La3Zr2O12 (LLZO) is a promising solid electrolyte for all-solid-state lithium-ion batteries. Some studies on LLZO synthesis have been conducted without considering the crystal structure of ZrO2 as the main precursor. In this research, different-precursors have been used for LLZO synthesis which was a monoclinic ZrO2 powder (m-ZrO2) and tetragonal ZrO2 powder (t-ZrO2). The reaction was conducted at 950 °C 6 h and followed by sintering at 1000 °C 6 h under Argon gas flow. The result shows that LLZO made from m-ZrO2 (LLZO(A)) and t-ZrO2 (LLZO(B)) contains t-LLZO and c-LLZO which is surprisingly having a similar c/t ratio of 0.124–0.125. The LLZO(A) and LLZO(B) provide a silver blocking ionic conductivity of 1.245 x 10−6 Scm−1 and 1.647 x 10−6 Scm−1, respectively. In addition, LLZO(B) provides lower specific resistance than LLZO(A) in between LiCoO2 and meso-carbon microbeads (mcmb) electrodes. CV analysis of the symmetrical Li-LLZO(B)–Li cell shows an electrochemical potential of 3.3 V (vs Li/Li+) oxidation and 3.4 V reduction (vs Li/Li+). A time-based Galvanostatic charge–discharge to Li-LLZO(B)–Li shows a capacity drop after the 1st 40 cycles from 0.0383C/cm2 into 0.0303C/cm2 during the 2nd 40 cycles, and it remains stable up to 120 cycles. It confirms the long-term electrochemical stability of LLZO(B) which was produced from t-ZrO2. The solid-state reaction method provides less expensive production and environmentally friendly by the absence of organic solvent.

Environmental literacy related to the utilization of medicinal plants in the community provides a foundation for the younger generation to take an active role and form an attitude of care and responsibility for environmental sustainability. The current research aims to introduce the Inquiry-Etnobotany (IEb) learning model to enhance students' environmental literacy. The research design applied a pretest-posttest control group design to assess the effectiveness of the IEb model intervention, comparing it with the inquiry and discovery learning models. Upon analysis, notable differences emerged between the pre-test and post-test results across various learning models. Specifically, the IEb model exhibited a substantial difference, indicating significant progress in student outcomes. Similarly, the inquiry model showcased an improvement, while the discovery learning model displayed a slightly smaller change. Furthermore, the disparities between pre-test and post-test outcomes were evident across the different schools involved in the study. The IEb model has a significant impact on enhancing students' environmental literacy. However, the research results in each school also demonstrate that various learning models enhance students' understanding of environmental issues despite the different levels of effect.

Li7La3Zr2O12 (LLZO) is a garnet-type electrolyte for all-solid-state lithium-ion batteries (ASSB). It has good chemical and electrochemical stability against lithium and a relatively high ionic conductivity. However, the ionic conductivity needs to be further increased to provide a high specific capacity of the ASSB. Element doping into LLZO is an effort to increase molecular defect, known to enhance the conductivity. This research studied the effect of the Na2B4O7 addition on the LLZO synthesis, producing LLZBO(A). The investigation aims to understand whether the sodium ions dope into the LLZO structure during synthesis, or it is only B ions to enter into the structure. Therefore, another synthesis with B2O3 of B precursor was conducted for comparison (LLZBO(B)). The precursors were mixed stoichiometrically by following the formula of Li7-xLa3-xZr2-xBxNaxO12 (LLZBO, x= 0.15; 0.20; 0.30). XRD analysis equipped with Le Bail refinement found that LLZBO(A) and LLZBO(B) mainly consist of cubic and tetragonal LLZO with a %mol of 69.06 – 69.84 %, and the main secondary phase is La2Zr2O7. The surface morphology of LLZBO(A) and LLZBO(B) is almost similar to the irregular form of large aggregates. The particles become more dispersed when 0.3 %mol dopant was submitted. Impedance analysis found a high ionic conductivity of LLZBAO(A)0.3 1.042x10-3 Scm-1.

Adsorption thermal energy storage plays a vital role in supporting the availability of renewable energy. Activated carbons produced from local waste biomass have been attracting considerable attention in adsorption technology due to their unique properties and sustainability. However, their limitation in water vapor uptake hinders the practical application of this material. In this work, acorn nutshells were utilized as a base material to produce activated carbon. Air oxidation was performed as a versatile and low-cost technique to enhance the material’s properties and water adsorption capacity. By applying air oxidation as a post-treatment during material production, the amount of active functional groups and the water adsorption on activated carbon has been successfully enhanced. From the theoretical calculation, it is found that activated carbon–water working pairs shown promising performance to be used for adsorption thermal energy storage applications. The adsorption of water vapor on the post-treated-activated carbon releases the isosteric heat between 2400 kJ/kg to 2500 kJ/kg. Moreover, this study’s working pair can be driven by a temperature of less than 50 °C. From the results, it is confirmed that by controlling the adsorbent’s surface properties, activated carbon–water working pairs can be a promising way to provide alternative material and reduce the energy demand for driving the system.

Introduction: Stunting continues to be a prominent health problem in Indonesia. Stunting prevalence is higher in children from poor families or living in rural areas; however, there has been a lack of information on predictors of stunting disparities and stunting risk factors by socioeconomic status (SES) and location of residence (rural or urban). This study aims to examine the factors associated with stunting by SES and rural-urban status, and to assess determinants of stunting disparities by SES and rural-urban status in Indonesia. Methods: This study analysed data from the Indonesian Family and Life Survey (IFLS) wave 5, conducted in 2014. Data for 3887 children aged 0-59 months, including individual, family and community variables, were analysed. Stratified logistic regression was conducted to assess differences in determinants of stunting by household expenditure (poor or non-poor, representing SES) and rural-urban status. The Oaxaca-Blinder decomposition method was used to assess determinants of stunting disparities by household expenditure and rural-urban status. Results: The analyses showed differences in factors associated with stunting among children in rural versus urban areas, or children in poor versus non-poor households. Mother's short stature and low education level increased the odds of stunting across all groups. However, in children of families with a higher household expenditure, unhealthy snacks were a significant predictor of stunting (adjusted odds ratio (aOR) 1.23, 95% confidence interval (CI) 1.04-1.47). This finding was not found in other groups. Good sanitation significantly reduced stunting in children in families with higher household expenditure and children from urban communities. Nutrition services were significantly associated with stunting in poor children and children from urban areas. The decomposition analyses showed that differences in characteristics explained 55.35% stunting disparity by household expenditure. Meanwhile, rural-urban disparity was mostly explained by differences in responses (56.20%), with low birth weight and unexplained variables as predominant contributors. Conclusion: There were slight differences in stunting determinants by household expenditure and rural-urban status in Indonesia. Stunting disparities were attributed to differences in characteristics and responses between the less and more advantaged populations. To improve the effectiveness of stunting reduction programs, specific interventions tailored to address the differences between the more and less advantaged population are needed.

Research to prepare NaFePO4 cathode material from iron sand was conducted. The iron sand consists of ilmenite FeTiO3 and hematite Fe2O3. A caustic fusion method used to precipitate iron as Fe(OH)3 and it increased Fe content up to 94.71 %. Phosphate precipitation successfully produced trigonal FePO4 and monoclinic FePO4 comply with ICSD#412736 and ICSD#281079. The prepared-FePO4 was then used as a precursor for Na insertion by applying cyclic voltammetry mode within 2.0 – 4.0 V with 0.05 mVs-1 of the scan rate. It produced orthorhombic olivine NaFePO4 and a secondary phase of orthorhombic Na0.7FePO4. Impedance analysis at 20 Hz – 5 MHz found that the material provided a semicircle at 100 Hz peak point, indicating electrode-bulk interface with a resistance value of 1735W, comparable to the electrical conductivity of 5.36 x 10-6 Scm-1. Even though the conductivity value is quite lower than NaFePO4 prepared from a commercial FePO4 that has been conducted in our previous research, however the electrical conductivity still reliable for cathode.

This research was aimed at synthesizing metal-organic frameworks (MOFs) based on zinc(II) and a benzene-1,3,5-tricarboxylate (BTC) linker in combination with graphite as anode material in lithium-ion batteries. The MOFs were prepared using sonochemical and solvothermal methods, which led to different materials: [Zn3(BTC)2·12H2O] (MOF 1) and [Zn(BTC)·H2O·3DMF] (MOF 2). The produced materials were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric/differential thermal analysis (TG/DTA), and a battery analyzer. Refinement of the XRD data was performed using the Rietica and Le Bail method. Sharp and intense peaks indicated that the materials had a high degree of crystallinity. The morphology of the materials as analyzed by SEM was cubic, with an average crystal size of 8.377 ± 4.276 µm for MOF 1 and a larger size of 16.351 ± 3.683 µm for MOF 2. MOF 1 was thermally stable up to 378.7 °C while MOF 2 remained stable up to 341.8 °C, as demonstrated by thermogravimetric analysis. The employment of the synthesized materials as anode in a lithium ion battery was proved to yield higher specific capacity and cycle stability compared to those using a graphite anode. The lithium-ion battery with 5 wt% MOF 1 exhibited the highest performance with an efficiency of 97.28%, and charge and discharge specific capacities of 123.792 and 120.421 mAh/g, respectively.

A research on the preparation of Carbon Waste Powder, CWP, was conducted and made from carbon rod waste which was extracted from used zinc-carbon batteries. This research was an effort to overcome environmental problem caused by battery waste by converting into adsorbent for methyl orange (MO) that frequently used by textile industries. The prepared powder was then analyzed to understand its characteristic peaks, crystallinity, and to compare the properties with other carbonaceous forms, i.e. a commercial Carbon Paper (CP), and a commercial meso- carbon micro-beads (MCMB). The analysis found that CWP is dominated by graphitic carbon. An adsorption experiment was then conducted to study their adsorption ability to methyl orange solution. The result found that those three carbonaceous materials have the ability to adsorb methyl orange with different activities. MCMB has the highest adsorption capacity of 0.197 mg.g-1. Meanwhile, CWP and CP show adsorption capacity of 0.066 mg.g-1 and 0.062 mg.g-1, respectively. Methyl orange adsorption on CWP and CP were under second order, which means the adsorption could be four times faster as the MO solution doubled. Moreover, the rate constant of MO adsorption on CWP is 8×10-4 min-1, which was higher than the rate constant of MO adsorption on CP. It confirmed that the CWP can be used as a promising adsorbent for dye waste water. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

At the factory of CV. Solo Button, coconut shell charcoal is made by heating the raw material in the open concrete reactor. This simple process results in minimal surface area characteristics and pore size, so the chrocoal is less suitable for the use as an adsorbent. Addition of treatment with degassing using N2 at temperatures of 200 oC and 300 oC can increase surface area, pore size and number of pore charcoal. The SAA and BET analysis showed an increase in surface area of 6.2% and 93.6% as well as an increased pore size of 14.5% and 12.29% at both temperatures. Adsorption-desorption graphs indicate that the untreated charcoal has uneven surfaces and the pores are not detected while the degassing treatment at these temperatures indicates the formation of micropores from the charcoal. Keywords: chrocoal, pore, surface area, coconut shell

The use of a Learning Management System (LMS) in education, including in English as Foreign Language classrooms, is widely deliberated ever since the appearance of Web 2.0 technology. Its use as a virtual classroom works as an alternative approach of teaching that allows teachers and students to perform various tasks and functions. For students, it eases them to both learn and practice the target language. This paper aims to report insights on how EFL students perceived the use of LMS, especially Edmodo. The researchers gathered data by interviewing four EFL students of a private Islamic university in Yogyakarta. The results clarify their impression towards Edmodo depicted in two main aspects; the features and activities when utilizing Edmodo. The participants reported a positive belief in the integration of Edmodo in language learning. The research also found that students' backpacks, quizzes, assignments, posts, and comments were useful features that assist them. Besides, the participants explained how they integrated Edmodo in the EFL classroom, including undertaking quizzes, submitting the assignment, practicing writing, speaking, reading, and listening. This study suggested that Edmodo is a valuable tool for learning languages.

Research on preparing yttria stabilized-zirconia film was conducted with polyacrylic acid (PAA) dispersant (YSZ film-A) and mix of PAA with surfactant blend as a dispersant (YSZ film-B). The YSZ powder was prepared by introducing nano-yttrium dioxide powder to nano-zirconia powder through solid-state reaction. The surfactant blend consists of sodium dodecyl sulfate, SDS (HLB 40), and Tween-80 (HLB 15) at a definite ratio to produce a required-HLB (Hydrophilic-Lipophilic-Balance) value. The prepared-YSZ films were analyzed to study its crystallinity, crystal structure and its cell parameters, surface morphology, particle size, the thickness of the film, thermal properties, the functional group content, and the electrical conductivity. The result found that both YSZ film is in cubic structure with a space group of Fm3m. The crystal structure is exactly similar to the YSZ powder. A characteristic peak of Zr (Y)-O vibration at 561.31–561.24 cm−1 appears from both YSZ film as well as from the prepared YSZ powder. SEM image shows YSZ film-A more compact than YSZ film-B, with the particle size of 11.92 ± 1.41 μm. Meanwhile, the particle size of the YSZ film-B is 14.41 ± 2.08 μm. Both YSZ film shows a proper ionic conductivity for solid electrolyte purpose at 600 °C, i.e., 2.08 × 10−4 Scm−1 and 2.25 × 10−4 Scm−1 for YSZ film-A and YSZ film-B, respectively. The measured activation energies (Ea) for ionic migration are 0.687 eV and 0.562 eV for YSZ film A and YSZ film-B, respectively. Keywords: YSZ film, Aqueous slurry, PAA dispersant, Surfactant blend, Solid electrolyte

The fabrication of Mg-Zn-Al Hydrotalcite (HT) was carried out by the co-precipitation method at various molar ratios. The Mg-Zn-Al HT compound at the optimum molar ratio was then calcined to determine the effect of calcination on the Pb2+ adsorption. The kinetics of the adsorption type was determined by applying pseudo first order and pseudo second order kinetics models. Meanwhile, to investigate the adsorption process, the Freundlich and Langmuir equations were applied to determine the adsorption isotherm. The results showed that the optimum Mg-Zn-Al HT was at a molar ratio of 3 : 1 : 1 with an adsorption efficiency of 73.16 %, while Mg-Zn-Al HT oxide increased the adsorption efficiency to 98.12 %. The optimum condition of Pb2+ removal using Mg-Zn-Al HT oxide was reached at pH 5 and a contact time of 30 minutes. The adsorption kinetics follows the pseudo second order kinetics model with a rate constant of 0.544 g/mg·min. The isotherm adsorption follows the Langmuir isotherm model with a maximum capacity of 3.916 mg/g and adsorption energy of 28.756 kJ/mol.

Conversion of wood waste into bio-oil with low temperature pyrolysis method has been successfully carried out using tubular transport reactors. Pyrolysis carried out at temperatures of 250-300°C without using N2 gas. Bio-oil purified by a fractionation distillation method to remove water and light fraction compounds. The materials obtained from different types of wood waste, namely: Randu wood (Ceiba pentandra), Sengon wood (Paraserianthes falcataria), Coconut wood (Cocos nucifera), Bangkirei wood (Shorea laevis Ridl), Kruing wood (Dipterocarpus) and Meranti wood (Shorea leprosula). Bio-oil products are analyzed for their properties and characteristics, namely the nature of density, acidity, high heat value (HHV), and elements contained in bio-oil such as carbon, nitrogen and sulfur content based on SNI procedures, while bio-oil chemical compositions are investigated using Gas Chromatography Mass Spectroscopy (GC-MS). The maximum yield of bio-oil products occurs at 300°C by 40%. Bio-oil purification by fractional distillation method can produce purity of 16-31% wt. The characterization results of the chemical content of bio-oil showed that bio-oil of methyl formate, 2,6-dimetoxy phenol, 1,2,3 trimethoxy benzene, levoglucosan, 2,4-hexadienedioic acid and 1,2- benzenediol.

Lithium titanate, LTO, was synthesized by solid state reaction with Li2CO3 and TiO2 powder as precursors. The result was characterized to investigate its crystal structure, phase content, cell parameters, surface morphology, electrical conductivity and its performance as electrode in a lithium ion battery. XRD analysis with Le Bail refinement showed that the prepared materials consisted of 4 phases of Li4Ti5O12, Li2TiO3, anatase TiO2 and rutile TiO2. The surface morphology was still not homogeneous, with an average grain size of 0.533 ± 0.157 µm. When 1% LTO was mixed with graphite and used as anode of an LFP battery, it produced a specific capacity of 130.66 mAhg 1 with Coulombic efficiency of 94.2%. When the composition was 5% of the total anode powder, the specific capacity was 118.74 mAhg-1 and Coulombic efficiency was 92.72%.

Masalah status gizi balita di Indonesia cukup memprihatinkan. Faktor predisposisi yang menjadi penyebab masalah ini masih sangat sedikit diketahui. Pendekatan teori Health Belief Model (HBM) diharapkan dapat menjelaskan faktor-faktor orangtua yang berhubungan dengan status gizi anak usia dibawah lima tahun. Tujuan penelitian ini adalah untuk Mengetahui hubungan pengetahuan ibu, pola pemberian makan, dan pendapatan keluarga terhadap status gizi anak usia di bawah lima tahun. Metode penelitian yang digunakan adalah metode kuantitatif dengan desain penelitian cross sectional. Populasi dan sampel dalam penelitian ini berjumlah 189 responden dan sampel berjumlah 65 responden dengan teknik simple random sampling. Analisis data menggunakan uji chi-square. Hasil penelitian menunjukkan bahwa variabel persepsi kerentanan yang dirasakan (perceived susceptibility) yang berhubungan dengan status gizi anak di bawah usia lima tahun yaitu pengetahuan (p = 0.034), pola pemberian makan (p = 0.008), dan pendapatan keluarga (p = 0.004). Penelitian ini menyimpulkan bahwa terdapat hubungan persepsi kerentanan yang dirasakan (perceived susceptibility) yaitu pengetahuan, pola pemberian makan dan pendapatan keluarga dengan status gizi anak usia di bawah lima tahun.

Exploration of the use of medicinal plants to lower uric acid levels has been widely practiced. Stages of new drug development research is a preclinical test using experimental animals, therefore the manufacture of an animal model of hyperuricemia is necessary. This study aims to determine the optimal induction of uric acid to increase blood uric acid levels by administering high purine foods such as cow’s liver, cow’s spleen, Gnetum gnemon, emping and fried peanuts. Eighty male white rats were used individuals to be divided into 4 groups, they were: (I) cow’s liver, (II) cow’s liver and cow’s spleen, (III) cow’s liver, cow’s spleen and boiled gnetum gnemon beans, and (IV) cow’s liver, cow’s spleen, emping and fried peanuts. This study using easy touch GCU to measure blood uric acid level. The result of statistical analysis of uric acid level means with 5 times repetition using One Way ANOVA showed that there was a very significant difference between treatments (p

Doping yttrium ions, Y3+ into ZrO2 produced Yttria-Stabilized Zirconia, YSZ. Various amount of yttrium ions could provide different ionic conductivity. This research investigated electrical conductivity of various YSZ composition, i.e., 4.5; 8.0 and 10% mol yttrium in ZrO2. The ZrO2 powder used was synthesized from zircon sand, a side product of tin mining plant, Bangka Island, Indonesia. Structural investigation on the prepared YSZ found that yttrium ion doping has changed the crystal structure of ZrO2 from monoclinic to cubic, even though the monoclinic and tetragonal are also still exist. The Y3+ doping changed the cell parameter of ZrO2 crystal. It indicates that the Y3+ entered into the ZrO2 structure and produced vacancy sites. The highest ionic conductivity is provided by 8% mol Yttrium doping or 8YSZ, i.e., 2.74×10-4 S.cm-1 at 700oC with an activation energy of 0.741 eV.

Uric acid is the end product of purine degradation. When uric acid levels exceed normal limits, it will build up and cause hyperuricemia. Allopurinol is one of the most effective and common medicine for hyperuricemia, but it brings serious side effects, therefore it is needed alternative therapy for hyperuricemia. One plant that may be expected to low uric acid levels is green tea (Camellia sinensis L.), that contains many antioxidants polyphenols, especially flavonoids. Flavonoid has strong antioxidant properties, act as free radical and metal scavengers, and also xanthine oxidase (XOD) inhibitors. This study investigates the potential of green tea using various doses of 150 mg/kg, 300 mg/kg, and 600 mg/kg of body weight in 24 white male rats (Rattus norvegicus) Wistar strain that has been received high purine diet in 60 consecutive days. This study used DHBSA methods to measure uric acid levels in blood serum and urine that excreted 8 hours before surgery. Green tea extract that contains polyphenol can inhibit XOD activities, therefore, it leads to decrease uric acid level in blood and increase the excretion through urine by modulating urate gene transporter. A therapy with 600 mg/kg body weight of GTE is the most effective dose to decrease uric acid levels in serum and to increase excretion of exceeding uric acid significantly (p < 0.01), from One Way ANOVA and Tukey analysis.

This research work reports on the potential of bagasse, a solid waste from sugar factories, to produce activated-carbon (AC) as an adsorbent. The activation was conducted under 500, 600, and 700 °C using steam as the activation agent to produce AC500, AC600, and AC700, respectively. The prepared-materials were characterized to understand their elemental content, surface morphology, thermal properties, functional groups identification, surface area, and pore size. AC700 provided the highest surface area of 592.36 m2/g and indicated the contribution of mesopores distributes along 1.5–8.0 nm of pore size. Therefore, an adsorption test was conducted with AC700 as adsorbent. The results show that methylene blue (MB) adsorption reached equilibrium after 30 min of adsorption time. The adsorption isotherm applied to a monolayer Langmuir isotherm was fitted by linearization, resulting in a constant R2 of 0.999. The MB adsorption to AC700 favorably occurred, as proven by the Freundlich parameter 1/n of 0.881, which is less than 1. The Dubinin-Radushkevich isotherm confirmed that the adsorption proceeded through physical interaction with adsorption energy of 3.536 kJ/mol.

In this research, a composite of ZrO2-TiO2 was used as a photocatalyst in the degradation of dye wastewater. The dye waste water is a single Methylene Blue, MB, wastewater from Batik industry. Meanwhile, the ZrO2 was prepared from zircon sand founded from Bangka Island, Indonesia. The composite was prepared at various weight ratio and heat treated at 500 oC. The result shows that the purity of ZrO2 from zircon sand is only 66.46 %. However, the addition of ZrO2 into TiO2 able to increase the photocatalytic activity proven by 88.75 % degradation of MB at a ZrO2-TiO2 weight ratio of 1:1. The result is higher than the degradation with anatase TiO2; that is only 62.67 %. The kinetics study found that the photocatalytic degradation of MB with single TiO2 has the rate constant of 1.85x10-2 minutes-1. Meanwhile, the rate constant of the MB degradation with the composite ZrO2-TiO2 is 16.73x10-2 minutes-1.

This paper discuss research about the optical properties and photo catalytic activity of TiO2 film on graphite substrate and its modification with ZnS. The optical properties investigated are the light response at various light wavelength and the gap energy (Eg). Meanwhile, the photocatalytic activity was studied from isopropanol degradation to determine the Quantum Yield, QY and kinetics of reaction. The results show that the TiO2 layer is consisted of rutile and anatase phases. Meanwhile, the ZnS peaks are at 2θ of 27.91o and 54.58o. The gap energy of TiO2/G consist of two band gap representing the band gap of rutile and anatase. The ZnS deposition shifted the band gap into single gap of 3.40 eV which is in between the gap energy of single TiO2 and single ZnS. The isopropanol degradation with TiO2/G photocatalyst under visible light radiation did not produce any new peaks representing product. Meanwhile, the photocatalytic process under 380 nm light produce new peaks representing the electronic transition of acetone. The isopropanol degradation with ZnS-TiO2/Graphite produced new peaks that indicates the photocataytic activity of ZnS-TiO2/Graphite whether under UV or visible light radiation. The siginificant role of ZnS also proven by the increase of QY values and the increase of rate constant, k. Copyright © 2015 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

This research study the mixed semiconductor of SiO2-TiO2 which was immobilized on graphite substrate and also studies the effect of surface modification on its mixed semiconductor. The surface modification was carried out by electrode position of Ag from 0.4 M of AgNO3 solution at various applied current. The electrode position was conducted for 30 minutes at 0.004; 0.008; 0.010; 0.012 and 0.014 A. In the electrode position cell, SiO2-TiO2/Graphite was used as cathode and a graphite rod was used as anode. The weight of deposited Ag was analyzed gravimetrically. The current efficiency of electrode position was calculated by comparing its experimental weight to its theoretical weight founded from calculation using Faraday’s equation for electrolytic cell. Meanwhile, the photo electrochemical testing was carried out to investigate the efficiency of induced photon to current conversion; it was measured as %IPCE (% Induced Photon to Current Efficiency). The crystallinity and crystal structure of the prepared materials were analyzed by X-ray diffraction and their surface morphology was analyzed by Scanning Electron Microscope (SEM). This research found that silver was deposited as silver metal, Ag and as silver oxide, AgO. The electrode position efficiency at applied current of 0.014 A is 92.30 % with diameter of cluster is 7 - 11.9 mm. It is founded that Ag and AgO deposition enhanced the efficiency of photon conversion into current up to 89.92 %. The optimum %IPCE value is at 28.6 % of Ag content. Ag-SiO2-TiO2/G has higher photo conversion than Ag-TiO2/G, shown by the %IPCE value at 300 nm is 83.25 % higher than Ag-TiO2/G. It indicates the significant role of silica network in photo excitation mechanisms in the composite material. © 2014 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)

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

The objective of this research is to study wheather the emulsion system of water/SDS (Sodium Dodecyl Sulphate)/ethanol/n-hexane can be transformed from S1 (hydrocarbon in water) type to S2 (water in hydrocarbon). CdS can be synthesized in the transformed product of microemulsion medium. The emulsion type transformation from S1 to S2 was conducted by adding n-hexane increment of 5 mL as hydrocarbon phase and stirring at 300 rpm for 2 minutes. The inversion point was defined from the measurement of emulsion conductivity and was supported by data of the droplet view under optical microscope. CdS was synthesized from reaction of Cd(NO3)2.4H2O with Na2S in phase transformed microemulsion medium. CdS cluster size was obtained from its UV-Vis spectrum and was characterized using X-ray diffraction to analyse the crystallinity and crystal system, then the influence of the variation of SDS amount to the CdS cluster size and its UV-Vis spectrum was observed.The result of this research shows that the system of n-hexane/SDS/water emulsion can be transformed from S1 to S2 type. The SDS amount in the microemulsion has influence the CdS cluster size. The larger amount of SDS added, the smaller of CdS cluster size was obtained. XRD data indicated that CdS cluster has been obtained with 40.613 % of purity. Keywords: emulsion system, nanoparticle semiconductor, CdS, sodium dodecyl sulphate

Thin film of TiO2 on graphite substrat has been prepared by means of chemical bath deposition. Cetyltrimethylammonium Bromide served as linking agent of synthesized TiO2 to graphite substrate.The optical microscope and Scanning Electron Microscope (SEM) indicate that surfactant concentration affects the pore morphology of thin film Surface Area Analysis (SAA) of thin film indicated that the pore of thin film included in mesopore category. The anatase phase of TiO2 quantity arised as the surfactant concentration increase, gave high efficiency of induced photon conversion to current efficiency (% IPCE). Keywords: thin film, TiO2, deposition, graphite

Research on the kinetics of electrode reaction during copper electro-deposition on the surface of TiO2/graphite has been conducted. The aims of this research are to determine the ratio of anodic reaction rate to cathodic reaction rate , the ratio of anodic rate constant to cathodic rate constant , the equilibrium constant when the reaction reach equilibrium condition and to study the polarization in the electro-deposition reaction. Copper was deposited electrochemically from CuSO4 solution at various concentration i.e. 0.1 M; 0.2 M; 0.3 M; 0.4 M; 0.5 M. In every 5 minutes during electro-deposition process, the pH changes in anode cell was recorded and the change of Cu2+ concentration was also analyzed by spectrophotometric method. The result shows that the reaction order of Cu2+ reduction is first order and the oxidation of H2O in anodic cell is zero order. The ratio of anodic rate constant to cathodic rate constant, is 4.589´10-3 ± 0.071´10‑3. It indicates that the reaction rate in cathode is larger than the reaction rate in anode and it allowed polarization. The electrochemical cell reached equilibrium after 25 minutes with the equilibrium constant is 8.188´10-10 ± 1.628´10-10.

Zirconia has been prepared from Zircon concentrate by caustic fusion methods. Zircon is a by product from tin ore concentration plant at Bangka island of Indonesia. Yttria Stabilized-Zirconia (YSZ) was prepared by introducing the 8 % mol yttrium oxide into zirconia and sintered at 1500 "žaC for 5 hours. In order to obtain constant oxygen vacancy of 8 % mol in Zirconia, an appropriate amount of Yttria and Calcia were introduced into Zirconia and the mixtures were heated at 1350 oC for 5 hours. Elemental composition was determined by SEM/EDX and XRF and lattice parameters were determined using X-ray diffraction method. Ionic conductivity was measured by complex impedance spectroscopy. The results show that doping of Yttria into Zirconia (YSZ) and Calcia-Yttria into Zirconia (CYZ) allows phase transformation of Zirconia from tetragonal with space group P42/nmc into cubic Fm3m and enhance the ionic conductivity. However, the prepared materials are porous and have not met the requirement for the electrolyte material yet.