ARTICLE | doi:10.20944/preprints202310.0687.v1
Subject: Chemistry And Materials Science, Ceramics And Composites Keywords: Zalacca Midrib fiber, microcrystalline cellulose, Interfacial shear strength, mechanical properties
Online: 11 October 2023 (09:23:42 CEST)
This research aimed to determine the effect of alkaline treatment on zalacca midrib fiber (ZMF) concerning various aspects such as thermal stability, crystallinity index, interfacial bonding, interfacial shear strength, water absorption capacity, as well as conducting Scanning Electron Microscopy (SEM). This investigation extended to evaluating the mechanical properties of composites enriched with microcrystalline cellulose with prosthetic socket materials available on the market. Subsequently, ZMF was obtained by splitting and soaking zalacca midrib for 12 hours. Each of ZMF was removed from the midrib and soaked in 5% sodium hydroxide for 3, 6, 9, and 12 hours. The composite material was molded by mixing 10% microcrystalline cellulose with a rotational speed of 150 rpm, maintaining a temperature of 40°C, and continuing the mixing process for 30 minutes. As a result of the alkaline treatment, several positive effects were observed, including increased fiber density, improved particle bonding, increased thermal compatibility, and cleaner fiber surfaces, attributed to reduced levels of hemicellulose, lignin, pectin, and other impurities as confirmed by SEM analysis. The microcrystalline cellulose added to the composite increased the interfacial shear strength, and tensile strength increased by 56.74%, composite flexural strength increased by 76.43%. The SEM analysis results showed that the composite with ZMF on the base fiber broke during the tensile test because fiber experienced an increase in interfacial bonding between fiber and the matrix. The water absorption test showed that untreated fiber had a higher level of absorption
ARTICLE | doi:10.20944/preprints202206.0283.v1
Subject: Social Sciences, Education Keywords: physics teacher; perception; judgment; differentiated instruction; technology
Online: 21 June 2022 (04:46:53 CEST)
There is a national shift in the new Indonesian curriculum to employ differentiated learning approach in addressing diversity of students’ needs and abilities. Teachers’ judgment obviously corresponds to the duty that takes physics teachers to monitor their students at individual level. Within Indonesian physics education research (PER) context, empirical study that has addressed this subject is still lacking. To fill this gap, eight Indonesian physics teachers’ experiences and limitations about their judgment within differentiated learning environment has been investigated through phenomenological study. Physics teachers were voluntarily recruited after they have declared their endorsement and personal consent to participate in the study. Our participants were distributed over several teaching experiences, geographic regions, and ICT experiences. The latter experience might be taken into account since, through this study, we would project upcoming developmental research about engaging recent technological approaches to cope limitations of teachers’ judgment. Online semi-structured interviews (~ 50 min) were conducted by the first author (P.H.S.) to all physics teachers. Other authors contributed in reviewing the interview protocol (E.I. and H) and training the first author’s pilot interview (H.R.). Model of teachers’ thought and action was implemented to uncover physics teachers’ experiences and limitations in making judgment within diverse students. Findings revealed that physics teachers have conceded that they should adapt learning process in order to meet heterogeneous students’ needs. Personal observation has mainly informed teachers to identify students’ differences. After students have been identified, they creatively designed learning transformations to accommodate spectrum of students’ abilities. Nevertheless, we discovered several limitations encountered by teachers particularly in terms of judgments’ equity, accuracy, and their workload. To overcome this, teachers indicated various and supportive attitudes about technology implementation to assist their judgment. Implications for technological development was provided to address obstacles during the teachers’ judgment.
ARTICLE | doi:10.20944/preprints202208.0198.v1
Subject: Social Sciences, Education Keywords: thematic analysis; Indonesia; physics education research; natural language processing
Online: 10 August 2022 (09:42:09 CEST)
Emergent physics education research (PER) literatures have been disseminated through academic publications within the community. The growing body of literatures over years challenge Indonesian PER scholars to understand how the research community has been progressed and what possible future work that should be emphasized. Nevertheless, previous traditional method of thematic analysis performed serious limitation when the number of PER literatures exponentially increased. Dealing with this large volume of publications, one of the machine learning studies namely natural language processing (NLP) was employed in this study to automate our thematic analysis among Indonesian PER literatures that are still limited to be explored. One of the well-known NLP algorithm, latent Dirichlet allocation (LDA), has been performed to extract Indonesian PER topics and their associated development between 2014 and 2021. A total of 852 papers (~ 4 to 8 pages each) were collectively downloaded from five international conference proceedings organized by Indonesian PER researchers. Before their topics were modeled through LDA algorithm, our data corpus should be previously preprocessed through several common procedures of established NLP studies. Findings revealed that LDA has thematically quantified Indonesian PER topics and described their distinct development over certain period. The identified topics from this study demonstrated that Indonesian PER community has established robust development in eight distinctive topics to the present. They begin with initial interest in focusing research on physics laboratory and following the research based instruction in the late 2015. Indonesian PER scholars sustained to study continuous topic on 21st century skill until 2019 which gave way to a focus on developing relevant educational technology to address several forms of students’ performance including scientific literacy and problem solving. There is still lack of Indonesian PER literatures that have been attempted to address qualitative aspects of physics teaching and learning.