The premise of this work is the modification of the properties of chitosan-based film for possible use in food packaging applications. The biofilm was prepared via thermal and mechanical treatment through blending polymers with chitosan using Polyvinyl Alcohol (PVA) and loading different types of chemical agents, i.e., citric acid (CA), succinic acid (SA), and tetraethoxysilane (TEOS). The modification was carried out under high-speed homogenization at elevated temperature to induce physical cross-linkage of chitosan polymer chains without a catalyst. The findings showed that PVA improved the chitosan films’ Tensile strength (TS) and elongation at break (Eb). The presence of chemicals caused an increase in the film strength for all samples prepared, in which a 5% w/w of chemical in the optimum composition CS/PVA (75/25) provided the maximum strength, namely, 33.9 MPa, 44.0 MPa, and 41.9 MPa, for CA-5, SA-5, and TEOS-5, respectively. The chemical agents also increased the water contact angles for all tested films, indicating that they promoted hydrophobicity. The chemical structure analysis showed that, by incorporating three types of chemical agents into the CS/PVA blend films, no additional spectral bands were found, indicating that no covalent bonds were formed. The thermal properties showed enhancement in melting peak and degradation temperature of the blend films, compared to those without chemical agents at the optimum composition. The X-ray diffraction patterns exhibited that PVA led to an increasing crystallization tendency in the blend films. The morphological observation proved that no irregularities were detected in CS/PVA blend films, representing high compatibility with both polymers.

Covid-19 is an infectious disease caused by acute respiratory syndrome coronavirus 2 (Sars-CoV-2), therefore a study is conducted to break the chain the spread of the coronavirus is a touchless automatic door. In this study, an automatic door is made, and this door uses an Arduino-based ultrasonic sensor. This research aims to be able to design and build sliding doors for automatic doors and can create an Arduino system that is suitable for automatic doors and can use ultrasonic sensors as a touchless medium. This research uses tools and materials, namely Arduino Uno, ultrasonic sensor, dc motor, l298n motor driver, and for the driving mechanism is a dc motor connected to the pinion sprocket and a chain connected to the door surface. This research designs doors in SolidWorks 2018 software and builds doors with specifications (Material: PVC, Height: 1900 mm, Width: 610 mm, Thickness: 40 mm, Mass: 7.5 kg, Weight: 73.5 N) in a street workshop in Leuweung Sawo Cilegon-Banten, as well as making an Arduino system for doors that can move automatically by making a coding program in the Arduino IDE software, for opening and closing the door with an ultrasonic sensor that is set at a distance of about 5 cm..

Preliminary study-design of a piezoelectric floor energy harvester

This study focuses on designing a touch-free door lock system based on Arduino, utilizing ultrasonic sensors, sound sensors, magnetic switches, and slot locks, following the Pahl and Beitz design methodology. The aim is to develop a reliable system that enhances convenience and reduces the need for physical contact with door locks. The results indicate that the ultrasonic sensor performs effectively in detecting distances, while the magnetic switch operates within a maximum reading range of 10 mm. However, the sound sensor demonstrated low accuracy, requiring multiple claps for successful detection. The findings suggest that the developed product functions as intended, though the limitations of the sound sensor highlight the need for further improvements to optimize precision and responsiveness.

Modeling of electromagnetic energy harvesting on the vehicle suspension system is presented in this paper. This study uses the up and down movement oscillation of the shock absorber to vibrate the SDOF module which is consist coil and a permanent magnet. The mathematical model is developed by using Faraday law to estimate the electrical response of the energy harvester. The effect of resistance load is admitted in the mathematical model its effect on the performance of the energy harvester. The effect is investigated for different values of frequency and resistance load. This method proposed regenerative absorber is effective and practical for renewable energy applications.