BIOPOLYMER-BASED FILM PREPARATION FOR POTENTIAL SMART FOOD PACKAGING MATERIAL APLLICATION

Public interest in colorimetric films for food freshness monitoring has increased recently. In addition to extending the shelf life of packaged food products, packaging materials are also required to provide current information about the freshness of the food while ensuring food quality and safety. The current work aims to prepare smart biodegradable films based on biopolymer-containing color indicators to monitor the quality of Decapterus spp. The pH-sensing colorimetric film was developed from a chitosan biopolymer modified using polyvinyl alcohol (PVA) and glycerol, as well as methyl red, as an indicator of fish freshness. The effect of using PVA and stirring conditions (temperature and time) on film production was evaluated on its physical appearance, water vapor permeability, and mechanical properties. The results show that the use of PVA can increase the transparency of chitosan films. Incorporating PVA into the film results in brighter and clearer colors compared to films without PVA. The temperature used in the preparation of the film solution has an influence on the mechanical properties and the water vapor permeability. The increasing stirring temperature leads to the enhancement of Young's modulus and the barrier properties against water vapor and moisture, still concurrently impacting a decrease in the film's yield strength and strain. Additionally, the film also exhibits responsiveness to pH during fish spoilage, with a color change that occurs from pink to yellowish. This confirms that the pH-responsive film resulting from this research has great potential to be applied as a real-time indicator of fish freshness during storage

Impact of Extended Intervals on Diesel Engine Performance with 15W-40 DH1 Lubricant Oil

Engine lubricant oil is crucial for minimizing friction between moving components within an engine, directly influencing the engine's reliability and lifespan. Determining the appropriate oil replacement intervals is essential, as extending these intervals necessitates more rigorous monitoring of both oil quality and engine condition. This study investigated the performance of SAKAI 15W-40 DH1 engine oil in the SAKAI Vibrating Roller SV526 over varying operational periods: 125 hours, 250 hours, 375 hours, and 500 hours. The research involved analyzing oil samples for viscosity, metal additives, total base number (TBN), and contaminants using Fourier Transform Infrared Spectroscopy (FTIR). Additionally, key engine performance indicators, including fuel consumption, valve clearance, and compression pressure, were measured. The findings revealed a gradual decrease in oil viscosity from 13.48 cSt to 11.56 cSt, approaching the minimum acceptable threshold of 11.45 cSt. Concurrently, the Fe content in the oil increased to 11 ppm, indicating wear, while the valve clearance in cylinder number three expanded to 0.48 mm, and compression pressure dropped from 31 kg/cm² to 28 kg/cm². Despite these changes, the oil remained within the standard operational limits, and the engine continued to perform adequately. However, based on the observed trends, extending the oil replacement interval to 500 hours cannot be conclusively recommended, as the oil's condition and engine performance may begin to decline beyond this point

Sustainable Biodiesel Production from Waste Cooking Oil and Crude Palm Oil Using a Custom Mini Pilot Plant

The widespread practice of reusing Waste Cooking Oil (WCO) in hawker food stalls, often for multiple frying cycles, presents a significant public health concern due to the degradation of the oil, which can lead to the formation of toxic compounds. These practices not only pose health risks, such as increasing the potential for cardiovascular diseases and cancer, but also contribute to environmental pollution when the oil is improperly disposed of. This study seeks to address these issues by converting WCO, along with crude palm oil (CPO), into biodiesel using a custom-designed mini pilot plant. The biodiesel production process involved a two-step reaction. The first step, esterification, was conducted using a 55:100 alcohol-to-oil volume ratio with 1% by volume sulfuric acid (H₂SO₄) as the acid catalyst, at 60°C, with a reaction time of 30 minutes and a stirring speed of 800 rpm. The second step, transesterification, utilized a 6:1 alcohol-to-oil molar ratio, with 1 wt.% sodium hydroxide (NaOH) as the alkaline catalyst, carried out at 70°C over the course of one hour. These conditions were carefully selected to optimize the conversion efficiency and to minimize the free fatty acid content, which is crucial for achieving a high yield of biodiesel. The results demonstrated that the mini pilot plant is highly effective in producing biodiesel from both WCO and CPO. The study also led to the development of a standard operating procedure (SOP) for the biodiesel production process, ensuring reproducibility and efficiency

Heat Distribution Simulation in a Square Aluminum 7075 Plate Using Laplace Equation and MATLAB

The efficient management of heat transfer from aircraft engines to the wings is vital for maintaining thermal efficiency and structural integrity in modern aircraft design. Excessive heating of the wings, caused by engine-generated heat, can negatively impact aerodynamic performance and safety. This study focuses on analyzing heat distribution in a square aluminum 7075 plate to better understand heat transfer mechanisms. Using the Laplace equation, implemented through MATLAB (2023 Online Version), we aim to simulate and analyze heat distribution on the plate. The numerical method employed in this research involves solving the Laplace equation with Neumann boundary conditions, which represent insulated edges. The Liebmann method is used to iteratively reduce error to less than 1%. Simulations are conducted on an aluminum 7075 plate of dimensions 4x10⁻² m x 4x10⁻² m under various temperature conditions at the edges. Numerical results show that at the 9th iteration, the error reaches 0.71%, while MATLAB simulations yield an error of 0.4681% at the same iteration. The heat distribution across the plate is clearly visualized, and the analysis indicates that increasing the number of grids improves both the clarity and accuracy of the simulation results. In conclusion, this study demonstrates that applying the Laplace equation via MATLAB is an effective approach for analyzing heat distribution in aluminum 7075 plates. The results show that a finer grid resolution enhances accuracy, with a 101-grid system providing particularly clear and precise heat distribution patterns. These findings contribute to the optimization of thermal system designs, especially in aviation-related applications

Comparative Analysis of Cooling Load Calculations: CLTD Method vs. Carrier HAP 5.01 Software for Hotel HVAC Design

This study examines the cooling load requirements of a hotel building by comparing two methodologies: the traditional Cooling Load Temperature Difference (CLTD) method and the Carrier Hourly Analysis Program (HAP) 5.01 software. The primary objective is to validate the accuracy and reliability of these methods in calculating cooling loads across different room types, from standard rooms to larger, more complex suites. The results show that the CLTD method consistently yields higher cooling load estimates, with discrepancies ranging from 3% to 14% compared to HAP 5.01 calculations. These differences are most significant in larger rooms, such as suites and owner’s suites, which have more extensive glass areas, higher occupancy, and more heat-generating equipment. The findings indicate that while the CLTD method is valuable for quick, preliminary estimates, the HAP 5.01 software provides a more precise and comprehensive analysis, taking into account hourly variations, equipment schedules, and other factors that impact cooling loads. This research highlights the need for careful selection of the appropriate calculation method to ensure the efficient design of HVAC systems, maximizing energy efficiency, and maintaining occupant comfort. The study concludes that for projects requiring high accuracy, particularly in complex or large spaces, dynamic simulation tools like HAP 5.01 are preferable. Detailed cooling load results and comparisons are provided in the supplementary documentation, offering further insights into the analysis and its implications for HVAC design

ENHANCING HIGH-SPEED PERFORMANCE: MODIFICATION OF BOOM BARRIER GATE WITH PUSH BRAKING SYSTEM FOR ETC APPLICATION

Congestion at toll roads has become a pervasive issue in contemporary times, predominantly manifesting at toll booths during the payment process. A noteworthy contributor to this congestion has been identified as the sluggish operational speed of boom gates. In response to this challenge, a modification strategy was implemented to enhance the operational efficiency of existing boom gates. The primary modification involved substituting the conventional electric motor with a more advanced Brushless DC (BLDC) motor boasting a power rating of 660 watts. Additionally, an innovative augmentation integrated a motorcycle disk brake system into the boom gate mechanism. Replacing the original electric motor's internal brake system with the disk brake system aimed to optimize the overall performance of the boom gate. The integration of the motorcycle disk brake system was further complemented by incorporating the push braking system (knoken braking system), serving as the actuator instead of the traditional motorcycle lever handle. This strategic substitution was instrumental in activating the disk brake function at the boom gate. During peak rush hours, the modified boom gate underwent rigorous testing at both the Ciawi and Kelapa Gading toll gates. Results from the trial activities unveiled a remarkable improvement in the boom gate's operational speed. Specifically, the opening speed demonstrated an impressive surge of 51 percent, catapulting from 548 ms to 265 ms. Similarly, the closing speed exhibited a commendable enhancement of 44 percent, elevating from 602 ms to 332 ms. Furthermore, the boom gate cycle per hour experienced a notable escalation, increasing by 25 percent from 356 to 449 cars per hour. These findings underscore the efficacy of the implemented modifications in ameliorating congestion issues at toll booths

Optimized Frame Design for Head Loss Testing Equipment Through Material Strength Analysis

This article presents the design and analysis of a frame for head loss testing equipment, crucial for evaluating flow losses in pipe installations. The objective was to develop a robust yet lightweight frame that could withstand the operational loads imposed by the testing equipment. The frame, which supports essential components such as pipes, venturi meters, elbows, and reducers, was constructed using ASTM A500 hollow sections with dimensions of 20 x 20 x 1.6 mm and 35 x 35 x 1.6 mm. These dimensions were selected for their balance between strength and weight, validated through strength analysis and SolidWorks simulations. Conducted at Universitas Mercu Buana, the project involved the design, manufacturing, and testing of the frame to determine its load-bearing capacity. The results from the SolidWorks simulations confirmed the frame's structural integrity, which was further validated by its successful application in a practical setup. This study demonstrates the effectiveness of a systematic design approach, integrating material selection, load analysis, and simulation to achieve an optimal solution. The findings contribute valuable insights into the use of ASTM A500 hollow sections in structural applications, particularly where both strength and weight are critical. This work sets a precedent for future designs in mechanical engineering, offering a reliable framework for developing durable and efficient testing equipment

Study of Eigenvalues and Matrix Eigenvectors Using MATLAB: Vibration Systems of Multi-Purpose Vehicle (MPV)

Vehicle vibration is a critical factor influencing both passenger comfort and vehicle performance. In this study, we analyze the multi-degree-of-freedom (MDOF) vibrational behavior of a multi-purpose vehicle (MPV) using matrix eigenvalue and eigenvector methods. The vehicle’s dynamics are modeled by developing a set of equations of motion that account for the forces acting on the front and rear tires, car body, and pitch angle. MATLAB is utilized to numerically compute the system’s eigenvalues and eigenvectors, representing the natural frequencies and vibration modes of the vehicle, respectively. The analysis focuses on the vehicle’s response to a 50 mm displacement at the front tire, simulating the effect of road disturbances. The resulting vibrations in the front and rear tires, car body, and vehicle pitch are illustrated over a 1-second time frame. The findings show that the front tire experiences the largest oscillation amplitude of ±1 mm, while the rear tire exhibits a much smaller displacement of ±0.04 mm. The overall car body displacement reaches a maximum amplitude of ±1.3 mm, indicating partial damping of the front tire vibrations. However, the results reveal that the vehicle’s suspension system lacks effective damping, as the vibrations do not decrease over time. This behavior could negatively impact ride comfort and safety, particularly on uneven roads. The study concludes that improvements to the vehicle’s suspension system are necessary to enhance damping performance. The presented MATLAB-based approach offers a valuable tool for analyzing and optimizing vehicle vibration systems

Performance Evaluation of Ammonia Refrigeration Systems in a Texturizing Plant

This study evaluates the performance of an ammonia refrigeration system used as a cooling medium in a texturizing plant. The analysis was conducted over a 10-day period, focusing on key performance indicators such as compressor work, condenser exhaust heat, refrigeration effect, mass flow rate, Coefficient of Performance (COP), and overall system efficiency. The data revealed that the system performed optimally on Day 5, achieving a peak efficiency of 91%, with compressor work at 304.1 kJ/kg and condenser exhaust heat at 1414.6 kJ/kg. In contrast, the lowest efficiency was recorded on Day 3, at 77%. The refrigeration effect reached its highest value of 491.3 kJ/kg on Day 3, highlighting efficient heat absorption despite lower overall system efficiency. On Day 4, the mass flow rate was 0.001049929 kg/s, with an actual COP of 1.39, while the ideal COP peaked on Day 10 at 1.69, reflecting the system’s theoretical maximum efficiency under optimal conditions. The study emphasizes the critical role of the condenser in the system’s performance. Optimizing the condenser’s operation by controlling temperature, pressure, and flow rates, alongside regular maintenance, significantly impacts system efficiency. The findings suggest that careful monitoring of operational parameters, including compressor work and refrigerant flow, can enhance the overall efficiency and reliability of ammonia refrigeration systems in industrial settings. This research provides practical insights into improving the cooling performance, reducing energy consumption, and ensuring consistent production quality in texturizing plants

COMPARING ROTATION-ROBUST MECHANISMS IN LOCAL FEATURE MATCHING: HAND-CRAFTED VS. DEEP LEARNING ALGORITHMS

The objective of this research is to conduct a performance comparison between hand-crafted feature matching algorithms and deep learning-based counterparts in the context of rotational variances. Hand-crafted algorithms underwent testing utilizing FLANN (Fast Library for Approximate Nearest Neighbors) as the matcher and RANSAC (Random sample consensus) for outlier detection and elimination, contributing to enhanced accuracy in the results. Surprisingly, experiments revealed that hand-crafted algorithms could yield comparable or superior results to deep learning-based algorithms when exposed to rotational variances. Notably, the application of horizontally flipped images showcased a distinct advantage for deep learning-based algorithms, demonstrating significantly improved results compared to their hand-crafted counterparts. While deep learning-based algorithms exhibit technological advancements, the study found that hand-crafted algorithms like AKAZE and AKAZE-SIFT could effectively compete with their deep learning counterparts, particularly in scenarios involving rotational variances. However, the same level of competitiveness was not observed in horizontally flipped cases, where hand-crafted algorithms exhibited suboptimal results. Conversely, deep learning algorithms such as DELF demonstrated superior results and accuracy in horizontally flipped scenarios. The research underscores that the choice between hand-crafted and deep learning-based algorithms depends on the specific use case. Hand-crafted algorithms exhibit competitiveness, especially in addressing rotational variances, while deep learning-based algorithms, exemplified by DELF, excel in scenarios involving horizontally flipped images, showcasing the unique advantages each approach holds in different contexts