Sebelas Maret University

About: Sebelas Maret University is a education organization based out in Surakarta, Indonesia. It is known for research contribution in the topics: Population & Public health. The organization has 10901 authors who have published 10832 publications receiving 33057 citations. The organization is also known as: Universitas Negeri Surakarta & Universitas Sebelas Maret.

Effects of multiwall carbon nanotubes on viscoelastic properties of magnetorheological elastomers

Abstract: The effect of different types of multiwall carbon nanotubes (MWCNTs) on the morphological, magnetic and viscoelastic properties of magnetorheological elastomers (MREs) are studied in this work. A series of natural rubber MRE are prepared by adding MWCNTs as a new additive in MRE. Effects of functionalized MWCNT namely carboxylated MWCNT (COOH-MWCNT) and hydroxylated MWCNT (OH-MWCNT) on the rheological properties of MREs are investigated and the pristine MWCNTs is referred as a control. Epoxidised palm oil (EPO) is used as a medium to disperse carbonyl iron particle (CIP) and sonicate the MWCNTs. Morphological and magnetic properties of MREs are characterized by field emission scanning electron microscopy (FESEM) and vibrating sample magnetometer (VSM), respectively. Rheological properties under different magnetic field are evaluated by using parallel plate rheometer. From the results obtained, FESEM images indicate that COOH-MWCNT and CIP have better compatibility which leads to the formation of interconnected network in the matrix. In addition, by adding functionalized COOH-MWCNT, it is shown that the saturation magnetization is 5% higher than the pristine MWCNTs. It is also found that with the addition of COOH-MWCNT, the magnetic properties are improved parallel with enhancement of MR effect particularly at low strain amplitude. It is finally shown that the use of EPO also can contribute to the enhancement of MR performance.

Effectiveness of Critical Thinking Indicator-Based Module in Empowering Student’s Learning Outcome in Respiratory System Study Material

Abstract: Research and development are aiming to develop critical thinking skills-based modules on the respiration system materials to empower the learning outcomes; verify the effectiveness of critical thinking skills-based modules with teaching materials in schools based on student learning outcomes. Research and development method are using Borg & Gall development procedure with nine phases. Data analysis that used for the research and development are qualitative and quantitative descriptive. Research and development results show that critical thinking skills-based modules on the respiration system materials were developed according to the indicators of critical thinking skills and knowledge dimension that visualised on the objectives, materials, activities and evaluation questions which are developed to empower the learning outcomes. The result of module effectiveness test, showed by Anacova test result are FCount = 180,4 on factual, conceptual, procedural learning outcomes which are visualised in the form of multiple choice questions and FCount = 40.2 metacognitive learning results are visualised in the form of essays.

Ruthenium Supported on High‐Surface‐Area Zirconia as an Efficient Catalyst for the Base‐Free Oxidation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxylic Acid

Abstract: Several ZrO2 -supported ruthenium catalysts were prepared and utilized in the oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) under base-free conditions. Full conversion of HMF and almost perfect selectivity towards FDCA (97 %) were achieved after 16 h by using pure O2 as an oxidant and water as a solvent. The catalytic tests show that the size of the Ru particles is crucial for the catalytic performance and that the utilization of high-surface-area ZrO2 leads to formation of very small Ru particles. Superior activity was obtained for catalysts based on ZrO2 that had been synthesized by a surface-casting method and has high surface areas up to 256 m2 g-1 . In addition to good activity and selectivity, these catalysts show also high stability and constant activity upon recycling, confirming the suitability of Ru/ZrO2 in the base-free oxidation of HMF.

Corporate governance and dividend policy in Indonesia

Abstract: Purpose – This study aims at examining the impact of corporate governance on dividend policy among Indonesian companies. There are two theories of the effect of corporate governance on dividend policy: substitution and outcome theory. Substitution theory argue that corporate governance have negative effect on dividend policy, while outcome theory argue that corporate governance have positive effect on dividend policy. Therefore, this study investigates the effect of corporate governance on dividend policy in Indonesia. This study aims at examining the impact of corporate governance on dividend policy among Indonesian companies. There are two theories of the effect of corporate governance on dividend policy: substitution and outcome theory. Substitution theory argue that corporate governance have negative effect on dividend policy, while outcome theory argue that corporate governance have positive effect on dividend policy. Therefore, this study investigates the effect of corporate governance on dividend p...