Profile of students' concept understanding in kinematics

This research aims to profile the understanding of physics concepts in kinematics material. Teachers need information on understanding physics concepts in designing their learning. The profile of understanding the concept of kinematics is revealed by administering a concept understanding test. The total number of tests for understanding the concept of kinematics is 30 items. The concept understanding profile is categorized into five indicators: (1) interpretation, (2) classifying, (3) inference, (4) comparing, and (5) explaining—the test applies to 49 students at SMA and MA in Madiun. Based on the profile description analysis results, it was obtained that students had a good percentage of the concept understanding indicator component (39.54%) and the smallest percentage of the interpretation indicator (17.60%). These results can be used as recommendations for facilitators and researchers in determining the learning model that will be applied and the concept of understanding the research topic that will be carried out

Identification of sea breeze front (SBF) characteristics in the dry season using doppler weather radar on the west coast area of south Sulawesi

Sea Breeze Front (SBF) is one of the important components of sea breeze circulation, which plays role in coastal area’s atmospheric dynamics. SBF causes significant changes in temperature and humidity profiles and initiates updrafts that induce convective activity. This study aims to determine the characteristics of SBF and its impact on convection activity using Doppler weather radar on the west coast area of South Sulawesi during dry season. SBF identification utilized PPI and CMAX products to detect convective clouds and SRI to estimate rainfall intensity, then verified it using Automatic Weather Station (AWS) and Automatic Rain Gauge (ARG). SBF was generally detected at 10.30–14.30 LT with an average moving speed of 2.04 m/s. The length of SBF ranges from 15.47–21.08 km and moves inland as far as 12.57–26.09 km with 0.51–0.89 km of column depth. There was a difference in the average value of solar radiation intensity up to 106 W/m2 and 0.5°C of temperature during SBF Days. SBF caused 17 events of convective activity with a maximum reflectivity value of 42–60 dBz and 4–8 km of cloud diameter. Five out of 17 convective activities indicated the occurrence of light rain on the surface

Fabrication of p-type (MCCO) thin film using DC magnetron sputtering as a preparator for thermoelectric module

Based on existing research, thermoelectric efficiency can be improved through material selection. In this study, the material used is CaCO₃ doped with Mn and Co₂O₃ to form CaCo3.5Mn0.5O9 material as a p-type thermoelectric material. The substrate used is glass. The stages in this research are material synthesis, sputtering process using DC Magnetron Sputtering machine to form thin films, and testing. The synthesis process includes grinding, calcination, and sintering. Grinding is done using a Ball Mill machine with a rotation speed of 250 rpm for 5 hours. Furthermore, the calcination step was carried out by heating the sample into a furnace at a temperature of 800°C for 10 hours. Then the sintering process was carried out at a temperature of 850°C for 12 hours. After the synthesis process is complete, enter the sputtering process using a DC Magnetron Sputtering machine for approximately 10 minutes. The gas used in this research is Argon (Ar). After the sputtering process was carried out, several tests appeared, such as the XRD test to determine the type of crystal, the ZEM-3 test to determine the Seebeck coefficient and resistivity, the thickness of the thin film formed, and the power factor test to determine the maximum voltage and power generated by the module formed. Several power factor test results were obtained, consisting of 107 μW/mK² at 100°C, 108 μW/mK² at 200°C, and 332 μW/mK² at 300°C and a thickness of 90.34 nm

Multiple inversions of Rayleigh wave dispersion curve for geotechnical site characterization using particle swarm optimization dan genetic algorithm

The inversion of the Rayleigh wave dispersion curve is a crucial step in the multi-channel analysis of surface waves (MASW) method, used to obtain the shear wave velocity (Vs) profile. The nonlinear and multimodal nature of the dispersion curve makes a global optimization approach, such as particle swarm optimization (PSO) and genetic algorithm (GA), the optimal choice for inversion. This study aims to compare the performance of multiple inversions of PSO (MI-PSO) and multiple inversions of GA (MI-GA) in solving the inversion problem of the Rayleigh wave dispersion curve. The test results indicate that the utilized MI-PSO outperforms MI-GA in terms of computational time and accuracy of the obtained mode

Shielding parameters of leaded cement mortar

The Cathode ray tubes (CRTs) represent more than 70% of global e-waste sets. The glass of the CRT is doped with lead to prevent emission of radiations especially electrons. The glass at the panel and neck of the CRT along with the cement mortar, a mixture of 70% neck glass and 30% cement (mix70), are investigated mathematically as shielding materials from photons having energies in the range 0.06-3 (MeV). Experimentally the material mix70 is tested at energies 0.238 and 0.583 (MeV). Good agreement was recognized between the calculated shielding parameters and that obtained experimentally while complete equality between the calculated parameters carried out using the online XCom software or Phy-X software except at low energies for concrete material. Glass from panel, neck and mix70 have acceptable shielding characteristics at and below the energy 0.238 (MeV) or generally at the X-ray region. Neck glass has good shielding parameters at the chosen energy region and it is nominated as a shielding material for many nuclear applications. To enhance the shielding characteristics of the material mix70 it should be compacted during preparation to get higher density. The present work tested the shielding properties of leaded glass composites to find out its integrity for practical shielding applications and radiological safety

The Effect of Volume Target on Quality of Radiotherapy using 3DCRT and IMRT: Dosimetry and Radiobiological Evaluation

The main goal of radiotherapy is to deliver the maximum possible dose to the target volume and the minimum possible to the surrounding healthy tissue. In this study, planning was carried out on the TPS Eclipse Varian Medical System using 3DCRT and IMRT techniques for 14 cancer patients. 6 cases of lung cancer with PTV were in the range of 175.1 cc - 875.5 cc, and eight brain cancer patients with a PTV range of 148.5 cc - 841.2 cc. This study aims to determine the effect of target volume on the quality of radiation therapy planning using the 3DCRT and IMRT techniques. The evaluation was carried out using dosimetry and radiobiology analysis. Dosimetry assessment analyzes the average dose, D98, D50, D2, CI, and HI on PTV and the average dose on OAR. Radiobiological evaluation by calculating the value of TCP, NTCP, and UTCP. The results showed that based on dosimetry and radiobiology evaluation, the IMRT technique provides better planning quality for radiation therapy by increasing the probability of cancer cells dying at PTV and reducing the risk of OAR compared to planning using the 3DCRT technique. The effect of PTV on planning quality using statistical regression tests showed that PTV did not significantly impact the quality of radiation therapy planning results either using the 3DCRT technique or the IMRT technique

Spectroscopic properties and optoelectronic parameters of ternary composites incorporating poly(L-Tryptophane):P(TER-CO-TRI) and Sudan dye

In this study, the spectroscopic properties and optoelectronic parameters of a ternary composite containing poly(L-Tryptophane): P(TER-CO-TRI) and Sudan dye were thoroughly investigated. Poly(L-Tryptophane) and P (TER-CO-TRI), the electron acceptor and donor, were solution processed and doped with different ratios of Sudan dye to form ternary composite systems. The FTIR technique, UV-Vis spectroscopy, and cyclic voltammetry (CV) were utilized to study the broad properties of the samples. Results showed that with the help of dye doping, the non-dispersive refractive index and energy gap of the ternary system were increased to 2.00 and decreased to 2.11 eV, respectively. The optical band gap, refractive index, dielectric constant, and optical conductivity of the samples were elaborated. The nature of the electronic transition in the studied samples was found to be a direct allowed transition, which was derived from the application of Tauc’s equation. The combination of CV test and absorption spectroscopy was successfully used to determine the molecular energy levels, HOMO and LUMO of the polymer samples

Measurement of Specific Heat of Organic Materials Using Non-Isolating Container and Arduino

This study reports a novel method for specific heat measurements of organic materials namely potaoes, quinces and radishes. The method proposed in this work is novel in the sense that it employs a non-isolated container and an Arduino microprocessors. The actual measurements are simply managed by placing the organic materials within hot water in a non-isolating container and by monitoring the temperature and time by means of Arduino UNO microprocessor. The heat leakage due to the non-isolated container is determined by using the heat versus time graph of the system and by mathematically modeling the temperature decrease by the time due to the heat exchange between the hot water and the environment. The measurements have revealed that the relative errors for the measurements are approximately % 4.75 for potatoes, % 21.50 for radishes and % 1.30 for quinces. The approach described in this work is inexpensive, very easy to apply and can potentially be beneficial for basic physics, science and engineering research activities

The balance In the six dimensions of space-time description of quantum mechanics phenomena and nature of time

This study presents a theory with a six-dimensional space-time structure, R^6, in order to describe quantum mechanic phenomena, the time arrow and quantum gravity. The interpretation of quantum world phenomena using four-dimensional space-time would be a very complicated and indescribable task. The dual wave-particle behavior, entanglement, quantum corridors, etc., represent the complex space-time structure. Previous studies indicate that complicated behaviors of particles in quantum mechanics are basically considered as the inherent behavior of those particles. The theoretical framework of the balance is the transformation of imaginary dimensions into geometric dimensions and the description of quantum mechanical phenomena using external Euclidean geometry. The six-dimensional space-time structure consists of three space and three time dimensions and the time arrow is the result of the impossibility of the existence of matter in six space-time dimensions, and the direction of the arrow is aligned with the expansion of the universe

Understanding of the Experimental Concept of Radiation Absorption of Radioactive Materials

In this article, we discuss the experimental absorption of radioactive light radiation on various materials using Geiger Muller. Under certain conditions, Geiger Muller can be used to determine the absorption coefficient of a material. The radioactive rays observed in this experiment are gamma rays. Gamma rays are radioactive rays that have no charge so they cannot be deflected by magnetic or electric fields and have the greatest penetrating power. We made several important results on experimental studies of the absorption of gamma radiation passing through matter. Our results relate to the trend of the unexpected, measured intensity of radiation versus the thickness of the absorber, which confuses students and cannot be explained by many laboratory assistants. Finally, we believe that a distribution function is an effective tool for examining the contribution of the build-up factor in the Geiger Muller calculation of the measured radiation intensity