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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.

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.

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.

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.

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.

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.