A Simple Simulation of Surface Plasmon Resonance in The Kretschmann Configuration Using Google Sheets

This article describes a simple numerical simulation of three-layer surface plasmon resonance (SPR) in the Kretschmann configuration. The calculation was performed in Google Sheets, a web-based spreadsheet environment that functions similarly to Microsoft Excel where it is easily accessible for students via the internet. Specifically, Fresnel’s equations were utilized to calculate the intensity of the reflected light for the p-polarized incident light on a three-layer system. The complex functions were utilized to plot the SPR curves. We examined the change of the resonance angle by the influence of the incident wavelength. The simulation was also performed for different thicknesses of the gold film layer. To demonstrate the sensitivity, we obtained the SPR curves with the variation of the refractive index in the sensitive medium. The SPR accuracy was analysed by comparing our obtained result with the published work. It is intended to incorporate into undergraduate instrumental analysis courses.

Optimization of The Electrospinning Process for Preparation of Nanofibers From Poly (Vinyl Alcohol) (PVA) and Chromolaena odorata L. Extrac (COE)

The Cromaloena odorata (COE) contains phenols, flavonoids, tannins, alkaloids, saponins, steroids that possess diverse therapeutic effects. However, COE has poor solubility in water and poor absorbtion in the body. Incorporation of COE in nanofiber system is a promising way to increase CEO solubility. One of the method to produce nanofiber is electrospinning. The electrospinning process there are three of the most important process parameters are applied flowrate, voltage and TCD. In this study we developed optimized condition for electrospinning process of polyvinyl alcohol (PVA)/CEO and their characterization. The Scanning electron microscopy (SEM) analysis showed that modification of flowrate and TCD did not affect the morphology of PVA and COE fiber. However fiber diameter decreased when lower flowrate, higher voltage was applied, and TCD. Fourier Transform Infrared (FTIR) study was conducted to identify possible intermolecular interaction between PVA/COE that has potential application as antimicrobial wound dressing.

Impact of Magnetic Field Strengthening on Combustion Performance of Low-Octane Fuel in Two-Stroke Engine

The impacts of strengthening magnetic field exposure on combustion performance of low-octane fuel have been examined experimentally. The combustion test was carried out using a 2-stroke 49 cc engine where the fuel was magnetized using a low magnetic field (<2 kG). Moreover, the molecular behavior of magnetized fuel was also characterized through spectrum tests using NIR and UV-Vis spectrophotometers. The result of this study indicates an exponential decrease of magnetized fuel consumption against the strengthening of magnetic field exposure. This exponential decrease of consumption can be related to the Arrhenius principle. In addition, the decrease of oxygen in the exhaust gas along with the strengthening of the magnetic field also confirms the increase of combustion reactions. Meanwhile, the increase of magnetized fuel absorption against ultraviolet and near-infrared lights along with the increase of the magnetic field intensity indicates a bond weakening, accompanied by the increase of molecular vibrational energy.

Influence of Problem Based Learning Model on Student Mental Models

The purpose of this study was to determine the development of mental models (MM) of students as well as to analyze the differences in MM based on the learning model used. This research is expected to be a guide for teachers in exploring the concept of physics as a whole. The study was conducted at the high school level with a medium level school category. The research method used mixed methods embedded experimental models with surface level, matching and deep (SMD) diagnostic test instruments. The results of the study showed that there were an increase on students’ MM at each meeting in the SMD level. Other results show that there are differences in the mean scores corrected between levels of the learning model. The mean score corrected PBL mental model is significantly different from conventional. The increase in MM students with PBL was higher than the increase in MM students with conventional learning. Thus, PBL can be recommended to increase MM students' physics of high school students.

Pre-Service Science Teachers’ Skills to Express The Algorithms Used in Solving Physics Problems with Flowcharts (An Example From Turkey)

Due to the nature of physics, problem-solving strategies are applied in some cases to teach many subjects. Problem-solving is a process that individuals use, not only in physics classes but also in every stage of life. An algorithm is a pathway to solving a problem or achieving a specific purpose. The purpose of this study is to identify how pre-service science teachers express the algorithms they utilize in the process of solving physics problems. The research design of the study was determined as survey design which is one of the quantitative research methods. The study was carried out with the number of 34 pre-service science teachers consisting of 1st and 3rd-year university students who took General Physics I and General Physics Lab I courses in the undergraduate program in science education at a state university. They were given three problems regarding classical mechanics and then asked to solve these problems and schematize their algorithms by using flowcharts. The International System of Units (SI) was used throughout the research. An evaluation was made by comparing the 3 algorithms of the solution, whose reliability and validity was ensured, and which was previously created with the help of 3 experts. In the study, descriptive survey model was used. Frequency tables were frequently used in the analysis of the data with the intent to present the study in the best way by doing an in-depth analysis. In the findings of the research, it was observed that pre-service science teachers had problems in expressing their algorithms and some of them could not express these algorithms at all. It was also observed that pre-service science teachers had difficulty describing the solutions they created while setting up the problem. However, it was observed that preservice science teachers who could illustrate their algorithms well were usually the ones who solved the problems correctly.

Development of Analogy-Based Material Physics Module to Provide Analogy Ability of Physics Teachers Candidates

It is known that the 'electronic structure of atoms' in material physics is microscopic. This atomic structure has an abstract and complicated concept, therefore good analogy skills are needed to study comprehensively. This research develops a free analogy-based material physics module to supply analogy skills to prospective physics teacher students. Module development uses the 4D model namely Define, Design, Development and Disseminate. The feasibility aspects are required based on the presentation, content, and grammar. Data obtained from expert assessment and trials using questionnaires, interviews, and tests. Increased student analogy skills were analyzed using normalized N-gain. The results obtained are: (1) the characteristics of the module that has learning steps such as teaching with analogy models, namely: introducing the concept of targets, reviewing the concept of analogies, identifying the relevant nature of targets and analogies, mapping analogies with targets, identifying analogies that are not relevant to targets, and make conclusions, (2) module quality on atomic electronic structure material developed is categorized as feasible, (3) modules are proven to increase mastery of the concept of atomic electronic structure (N-gain = 54%) and analytical skills prospective teachers physics (N-gain = 56%). The development of physics modules based on free analogies can be applied to other learning, such as biology, chemistry, and mathematics to explain abstract material.

The Development of Experimental Absorption Based on Arduino-Uno and Labview on Light Radiation by Colourful Surface

This development research aims to make a tool and test its ability to absorb the heat in light radiation by colored surfaces (black, dark green, blue, white). The benefit of this research is to present a simple laboratory that can be used in physics education class as a test tool for heat absorption. The research method that applied is Microcomputer Based Laboratory (MBL). The software that used is LabVIEW which connected to Arduino Uno hardware and heat source. The appropriate set of tools and materials is then tested for eligibility. The feasibility test of the device is reviewed from the aspect of content, linguistic, presentation and graphic by an expert validator as well as the compatibility of the findings with the theory. The results found that the darker the color of the object, the greater the ability of heat absorption and vice versa. Changes in power at a light source can affect changes in maximum temperature in the color absorption of heat. The greater the power provided by the light source, the greater the increase in maximum temperature. This development research concludes that the tools are feasible to use and appropriate based on existing theories.

Realization of Polarization and Malus’s Law Using The Smartphones

This work provides an approach for simplifying and teaching of the confusing topic of Polarisation of light and relating Malus’s Law. Teaching Polarisation and the Malus’s Law are modestly achieved by means of smartphones with a convenient light meter application. The apparatus is designed so that the polarizer, the analyser, the laser light source and the smartphone are precisely aligned on a rail. During the performance, the angle of the analyser is basically varied with respect to the polariser and the transmitted light intensity is measured by the light meter application. The results clearly show that the transmitted light intensity is directly proportional to the squared polarization angle. The approach surely provides accessibility for physics teachers and would help students to learn and internalize Polarisation and relating Malus’s Law in a better manner.

Relationship Between Behavior of Learning and Student Achievement in Physics Subject

Behavioral problems become special attention to learning. Some teachers confronted with a variety of student behaviors and varied learning outcomes. This research was aimed to determine the relationship between learning outcomes and student learning behavior with ranking score. A total of 91 of 10th-grade students with three different classes became respondents. The research was used Mixed methods with the sequential explanatory approach. Quantitative data were obtained by giving multiple-choice questions. The interview method was used to collect qualitative data. Kruskal Wallis test was used to analyze quantitative data and the interview transcript analyzed by the keyword of student behavior in learning physics. The results show that behavior while learning is very significant towards student learning outcomes. Interview findings show that student behavior during the learning process could affect learning outcomes.

Prediction of Dengue Hemorrhagic Fever Cases Based on Weather Parameters Using Back Propagation Neural Networks (Case Study in Pontianak City)

Research has been conducted by predicting cases of dengue hemorrhagic fever based on weather parameters. The data used are weather parameters in the form of air temperature data, air humidity, rainfall, duration of solar radiation and wind speed as input data and data on dengue hemorrhagic fever cases as the target data. This study aims to see the confirmation of dengue hemorrhagic parameters in Pontianak. The benefit in the field of education is that students and teachers are aware of the dangers of dengue because it can cause death. The method used is back propagation neural networks with the best network architecture in predicting cases of dengue hemorrhagic fever are [50 40 30 1] and binary sigmoid activation function, bipolar sigmoid and linear function. The activation function will determine whether the signal from the neuron input will be forwarded to other neurons and is also used to determine the output of a neuron. Network training correlation value is 0.9995 (very strong correlation) with MSE 0.0001 and network testing is 0.9325 (very strong correlation) with MSE 1.61. Determination coefficient serve as accuracy with values obtained is 0.85, which means that 85% of weather parameters can be used as input in predicting the incidence of dengue hemorrhagic fever in Pontianak City.