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The present work investigates the edgewise compression failure for honeycomb paperboards. Various panels are tested under a fixed loading rate with varying aspect ratios. The influence of the varying properties aspect ratio on yield strength is recorded. The experimental results indicate that the honeycomb paperboards are subject a decrease in yield strength with an increase in aspect ratio towards more slender bodies. Buckling was not observed in any of the tested specimens. All experiments are conducted under the general framework of ASTM C364/C364M -16 with a few noted changes.

Soap is a compound of sodium or potassium with fatty acids from vegetable oils or solid animal fats, soft or liquid, and foamy. Considering the potential of VCO as the raw material for making soap and supported by the benefits of red betel leaves, then this research is done by making solid bath soap from VCO which is supplemented with Red betel leaf extract. The purpose of this research is to make solid soap from VCO with an extract of red betel leaf based on SNINo.06-3532199. Analyzing VCO oil, which is used for the manufacture of soap, consists of analysis of saponification figures, Iodine number and peroxide number. Has made solid soap from VCO oil with Red betel leaf extract. From the five quality standards established under SNI 06-3532-1994 only two quality standards that can be done that is water quality and the amount of acidity. The percent of water quality obtained is 10% meanwhile the amount of acidity obtained is 9,32%. According to the data, it can be concluded that the solid soap made was not fulfill SNI 06-3532-1994.

This study was conducted as a response to address the problem of land availability for Cipayung landfill that no longer able to accommodate waste generation Depok City and to protect water pollution in receiving water body. Law No. 8/2008 explained that local governments and cities are required to create a sanitary landfill as a final waste processing system to replace open dumping that had been done by almost all the final processing of waste in cities in Indonesia. Sanitary landfill is the final waste processing system that works best and is environmentally friendly. The sanitary landfill will generate leachate. Leachate is the result of precipitation, evaporation, surface runoff, water infiltration into the waste, and also including the water contained in the waste. The purpose of this study was to determine the utilization of leachate generated by three years aged reactor.This study use a modeling tools as bioreactor landfill tank or so called lysimetric, that made of the polymer material that susceptible to high heat and pressure. This bioreactor landfill tank has a diameter of 0.83 m, with a surface area of 0.54 m2 and a height of 2.02 m, with the examination duration of 115 days. This tank consists of several layer, such as sand layer, solid waste layer, water layer and piping system. These layer has 3 year aged. The In this research, leachate recirculation in bioreactor landfills was conducted with waste layered loading systems with percolation system. This research has been conducted since the beginning of 2016, sampling, field measurement and analysis of leachate and waste quality carried out for approximately 115 days of field measurements.Several parameter were measured such as pH, BOD, COD, nitrate, nitrite and TSS. From the analysis of the leachate quality parameters of pH, BOD, COD, nitrite, TSS, showed a reduction in the concentration of the three reactors. The concentration of parameters measured at the initial stage until the final stage, showed a reduction in the concentration of the parameters, even reaching 90% reduction for BOD (biological oxygen demand), COD, (chemical oxygen demand) nitrite, and TSS (total solid suspended) parameters. So it can be concluded that the recirculation of leachate of the sanitary landfill can reduce the concentration of pollutants in the leachate that will be discharged into water bodies, thereby reducing the pollution of the receiving water body. This research is funding by PUPT Kemristekdikti and DRPM UI

In this study, determine of spray droplets size (SMD) using water sensitive paper (WSP) at low fluid pressure with deflector nozzle or tangential flow nozzle model Delavan AL75 and New Design Nozzle with two different type of swirl (ND2.5 A1.0 & ND2.5 B1.0). These three deflected flat sprays have used at different liquid mixing ratio. These liquid mixture ratios are pure water, 10% of lime juice + 90% of water (L10W90) and 30% of lime juice + 70% of water (L30W70). WSP is used to collect the spray droplets from nozzles. The operational liquid pressure of each nozzle is 3 bar, while air operational pressures are 3 bar and 6 bar. Then, the WSP were scanned using scanner then it was analyzed using ImageJ software. ImageJ can be used for determining the diameter of droplets size on the WSP. As the results from an experiment, the AL75 nozzle recorded the lowest Sauter mean diameter which is 193.69um at 6 bar of pressurized air while ND2.5 A1.0 recorded the highest Sauter mean diameter which is 353.61um at 3 bar of pressurized air. Summary from the experiment shows that the higher of droplet size is because of the lower air pressure (3 Bar). Then, increasing of liquid viscosity also increase the SMD. The orifice diameter for New Design nozzle (ND-2.5) is smaller than AL75, which are 2.5mm and 2.8mm respectively. The different nozzle design also gives effect the SMD. WSP is an alternative method to determine SMD for spray droplets with the low cost if compared to Phase Doppler Anemometry (PDA).

This paper investigates the Subassembly Process Automation (SPA) program’s application and impact on industrial manufacturing processes, particularly underscoring its efficacy in refining production accuracy and efficiency. It explores SPA’s systematic advancements and the incorporation of meticulous quality control strategies, focusing on how it streamlines operations, boosts efficiency, and ensures adherence to industry norms. The SPA program integrates automation for comprehensive process oversight, including job initiation, ongoing production, and critically, scrap reduction, thereby markedly diminishing waste and upholding rigorous quality standards. Offering an indepth evaluation of SPA’s capabilities, the paper illustrates its role in enhancing production flow and supporting environmental sustainability through effective scrap management. By analysing its implementation in crimping operations, from equipment preparation to production execution, the research highlights SPA’s essential contribution to reducing errors, maximizing resource efficiency, and maintaining exceptional manufacturing quality.

A statistical analysis was performed to evaluate the effect of factor and to obtain the optimum configuration of Kraft paper honeycomb. The factors considered in this study include density of paper, thickness of paper and cell size of honeycomb. Based on three level factorial design, two-factor interaction model (2FI) was developed to correlate the factors with specific energy absorption and specific compression strength. From the analysis of variance (ANOVA), the most influential factor on responses and the optimum configuration was identified. After that, Kraft paper honeycomb with optimum configuration is used to fabricate foam-filled paper honeycomb with five different densities of polyurethane foam as filler (31.8, 32.7, 44.5, 45.7, 52 kg/m3). The foam-filled paper honeycomb is subjected to quasi-static compression loading. Failure mechanism of the foam-filled honeycomb was identified, analyzed and compared with the unfilled paper honeycomb. The peak force and energy absorption capability of foam-filled paper honeycomb are increased up to 32% and 30%, respectively, compared to the summation of individual components.

Bio-based composites are a research topic since several decades, which aims for sustainable and durable materials. In the scope of this research, many different sources for biobased reinforcements have been investigated. Typical issues associated with the use of such are property variations due to cultivation area and climate, besides the influences of the type, pretreatment and fibre geometry. Another issue can be the availability of such natural fibres. Due to these reasons, we started using paper sheets as reinforcements in laminate composites with thermoplastic materials. In preliminary studies with polypropylene composites, we found good mechanical properties, even higher than could be expected by estimating the composite properties from the constituents by applying simple rule of mixtures type models. We suspect, besides some effect of paper compaction, interlaminar effects to be the reason for this. Therefore, the aim of this work is to investigate the effects of the interfacial interaction on the different paper laminate properties due to different matrix polymers. For this work, we used polypropylene, polyamide 6 and 12 as well as polystyrene. Composites were produced via compression moulding and samples for mechanical testing and density evaluation were cut from the moulded plates. The results from mechanical tests show, that there is a reinforcing effect, regardless of matrix polymer used. Simple rule of mixtures evaluations show, that the different matrices exhibit different degrees of interaction, based on their chemical structure. In addition, also influences due to processing were found.

Utilization of ginger pulp waste from herbal medicine and instant drinks industry in Indonesia currently used for fertilizer and fuel, whereas the ginger pulp still contains high oleoresin. Active paper packaging were developed incorporated with ginger pulp oleoresin (0%, 2%, 4%, and 6% w/w). Physical (thickness, tensile strength, and folding endurance, moisture content), sensory characteristics and antimicrobial activity of the active paper were evaluated. Selected active paper then were chemically characterized (functional groups). The additional of ginger pulp oleoresin levels are reduced tensile strength, folding endurance and sensory characteristic (color, texture and overall) and increased antimicrobial activity. Due to physical, sensory characteristic and antimicrobial activity, active paper with 2% ginger pulp oleoresin incorporation was selected. Characteristics of selected paper were 9.93% of water content; 0.81 mm of thickness; 0.54 N / mm of tensile strength; 0.30 of folding endurance; 8.43 mm inhibits the growth of Pseudomonas fluorescence and 27.86 mm inhibits the growth of Aspergillus niger (antimicrobial activity) and neutral preference response for sensory properties. For chemical characteristic, selected paper had OH functional group of ginger in 3422.83 cm-1 of wave number and indicated contain red ginger active compounds.

Antimicrobial properties of active paper packaging incorporated with cinnamaldehyde and its application in the storage of agricultural products had been studied. However, changes in grammage, tear resistance and water vapor transmission rate (WVTR) of the active paper during storage is not yet known, whereas it is important to provide consideration in application of the active paper. This study aims to determine the changes in those physical properties during storage (20 days) at various temperatures (10, 20, 25, 30, and 40 degC). The grammage and WVTR of the active paper decreased as increase in storage time and temperature, while the tearing resistance increased as storage time. Higher temperature caused slower increase in tearing resistance, but the results showed fluctuation. The results of Arrhenius plot indicated the activation energy (in kJ/mol) of those physical properties, sorted from the highest to the lowest as follows: 53.6 (grammage), 14.8 (WVTR) and 13.8 (tearing resistance).

Cellulose from mulberry paper waste was converted to carboxymethyl cellulose (CMCm) by etherification using chloroacetic acid and various sodium hydroxide (NaOH) concentrations (30-60 g/100 mL). The degree of substitution of the various CMCm materials produced ranged between 0.33-0.45. The chemical structure of cellulose and the synthesized CMCm materials was characterized using Fourier transform infrared spectroscopy. CMCm films were cast and tested. The tensile strength (TS) and percent elongation at break (EB) of the films were investigated. The highest TS (32.58 MPa) and EB (2.39%) were found using the 50g /100 mL NaOH-synthesized CMCm film. The effect of glycerol as a plasticizer on TS and EB of this CMCm film was also evaluated. Increasing the glycerol content decreased TS and increased EB of the CMCm films.

The paper reviews the recent studies on the lipid extraction of microalgae that mainly highlighted on the cell disruption method using variety of microalgae species. Selection of cell disruption method and devices are crucial in order to achieve the highest extraction percentage of lipid and other valuable intracellular (proteins, carotenoids and chlorophylls) from microalgae cell. Pulsed electric field (PEF) and electrochemical lysis methods were found to be potential for enhancing the extraction efficiencies either conducted in single step extraction or used as pre-treatment followed by conventional extraction method. The PEF technology capable to extract lipid as high as 75%. While, electrochemical lysis treatment capable to extract lipid approximately 93% using Stainless Steel (SS) and Ti/IrO2 as the cathode and anode electrode respectively. PEF technology and electrochemical lysis are still considered to be a new method for microalgae lipid extraction and further investigation can still be done for better improvement of the system.

The effect of exposure to the focused light from the xenon arc lamp on the surface tension of molten enamels was studied with a designed light beam setup as compared to that observed in conventional heating in a resistance furnace. The objects under investigation were enamels No. 261, UES-200 and UES-300. The power density of the light beam was varied in the range of (30-80) W/cm2. When exposed to light, the surface tension is shown to be an order of magnitude lower than that obtained in conventional furnace heating.

Leaf spring is the key component of the vehicle suspension system that affects the mechanical behavior of vehicle vibration, stability, damping, and other aspects like comfort. However, depending upon the geography and road conditions, its fatigue life may vary. In Nepal, public vehicles operate mainly on paved roads and gravel roads under variable loading conditions. The road tested in this paper includes an urban road ranging 45km from Ratnapark to Sundarijal. The road consists of paved surfaces and gravel roads with varying degrees of slopes, potholes, and cracks. This paper discusses the fatigue life of a leaf spring in a public bus (TATA-709) operating on an urban road. Miner’s rule is used for the experimental analysis. Miner’s rule requires real-life data for the number of stress cycles. The data is obtained from the public bus using the data collection module. The number of repeated stress cycles was computed using the Rainflow cycle counting method and, the fatigue life is calculated implementing Miner’s rule. To validate the experimental results, fatigue simulation is carried out in ANSYS. The stress history data obtained from the experiment is fed into the fatigue model in ANSYS. The result shows that the number of cycles to failure obtained from ANSYS exceeds the number of cycles of failure obtained from Miner’s rule by 5%. This discrepancy indicates the need to consider further factors beyond this study, such as rusting, creep, and pre-stress, which considerably change the material properties and fatigue. This study sets a method to determine the fatigue life cycle of a leaf spring in various road and loading conditions both experimentally and numerically, to avoid potential damage due to failure of the suspension system in a public vehicle.

The study of modal behaviour for vehicle body panels represents a field of interest for automotive engineering, having a major influence on automotive comfort, with respect to vehicle noise, vibration and harshness, but also concerning the durability of vehicle body. The investigation of natural frequencies and vibration mode shapes is crucial in the design phase, because essential information can be obtained concerning the behaviour of the components in dynamic conditions. The current paper focuses on the investigation of vibration modes and frequency response function on an aluminium alloy sheet. The aim of the paper is to perform the study of modal behaviour both experimentally and theoretically, through measurements using the impact hammer method and respectively through finite element analysis. The CAD model of the aluminium alloy sheet has been developed in Catia V5 environment in view of elaborating the finite element model, which has been used for investigation of modal behaviour, taking into account the case of free vibrations. Through the modal finite element analysis performed in Ansys Workbench, the natural frequencies of the aluminium alloy sheet, as well as the corresponding mode shapes have been obtained. Experiments have been performed on an aluminium alloy sheet, mounted on an elastic support with low natural frequency. The impact hammer method has been used for obtaining the natural frequencies, through frequency analysis of accelerations measured with two piezoelectric accelerometers mounted on the aluminium alloy sheet. The frequency response function has been computed from the response acceleration measured on the aluminium alloy sheet and the impact force measured using the force transducer of the impact hammer. Virtual instruments have been developed in LabVIEW environment for data acquisition, time domain and frequency analysis, as well as for determining the frequency response function using the measured signals. The natural frequencies obtained from the finite element analyses have been compared to the results of measurements and very good similarities have been ascertained. The experimental investigation of modal behaviour contributed to the validation of the finite element model, but further research is required to investigate the possibilities of improving the modal behaviour of the aluminium alloy sheet.

Lately, the rapid growth of traffic led to the construction of a new freeway bridge to ease the road congestion. This paper studied the crash behaviour of steel guardrails for semi-heavy traffic roads used on bridges. The guardrail structure is tested according to the SR EN 1317 standards at two velocity cases, corresponding to the TB 11 and TB 51 impact test description. To perform this evaluation study, the guardrail structure is first modelled in CAD environment software, respecting the commercial dimensions. The boundary conditions, the material properties assignment, and the load case creation are done by using dedicated FEA software. The obtained results are analysed and are proposed some design improvements to the base guardrail structure. The improved guardrail structure is tested under the same work conditions as the base structure. The conclusions of this research are presented in the last part of the paper.

The concept of Passive Safety aims to reduce the harmful effects on vehicle occupants and pedestrians in the event of an accident. Intelligent car bodies and restraint systems have been designed. Thus, side, front, knee and head airbag systems have been introduced, as well as pre-strained seat belts and force limiters. The objectives of car manufacturers are not only to reduce injuries that can cause death, but also a significant reduction of those that can result in permanent damage such as a whiplash. Advanced airbag systems are currently introduced, which offer protection to the occupants at the knees, torso, hips and abdomen. The topic proposed in the paper concerns both theoretical research on the operation of passive security systems, respectively the airbag system, and experimental research. Regarding the theoretical research, this paper proposes a virtual prototyping method by means of the LS Dyna software package of the airbag system functioning in order to protect the driver in the event of a frontal collision. For the analysis of the airbag system functioning, a complex assembly which contains of a dummy, seat, steering wheel, passive safety systems was used. For the experimental research a stand was designed for the analysis and testing of the airbag system, which has the role to protect the driver in the event of a frontal collision of the vehicle. In order to carry out the experimental tests, it was proposed to create a sledge type stand, which simulates frontal collisions.

This paper aims at assessing the influence of data aggregation on the estimation of the accidents’ severity. For this purpose, 27,400 accidents are investigated on three aggregation levels: individually (idl) which is highly disaggregated hourly (hrl), and daily (dil). A Severity Score (SS) is defined based on the injuries’ severity and relative cost weights. Multiple Linear Regressions are developed by assessing the SS’s variation as a collective explanatory effect of 83 predictors related to road environment, weather and lighting conditions, adherence conditions, and number of the involved vehicles. F and t tests are employed in order to assess the developed models and to investigate which variable is of statistical significance. This research shows that the higher the level of aggregation is, the higher the coefficient of determination. SS_dil model has the higher R2value and direct relationships between SS and the number of accidents occurring in “U” curves, on roads with no shoulders, where the roadway was covered with slime or black ice and where the roadway was wet was found. One of the interesting findings of this paper shows that in the models with low R2values (based on individual and hourly aggregated data), snow and fog significantly explain the variation of SS. As these are seasonally and short time phenomena, a further research should be focused on how the estimated models based on individual or hourly aggregated data could be improved by adding other significant predictors related to driver’s and vehicle’s characteristics and road environment’ features.

The paper presents the evaluation of the feasibility of a single-seat solar prototype vehicle for the World Solar Challenge competition, by estimating its autonomy. The research carried out contains several stages of study, including the development of mathematical models that are intended to be accurate enough to provide realistic predictions on the functional behaviour of the battery pack, so that it can be determined whether the designed vehicle will be able to complete the stages of the proposed competition. The paper also presents the CFD modeling approach, and the results obtained after simulating different body shapes advancements. In addition, the functional modeling approach is presented to evaluate the vehicle battery range, including the possibility to use different designs and types for the battery pack and to verify if the designed vehicle can achieve the race finish line.

Due to progressive increase of complexity, the automotive industry is subject to constantly changing trends varying from the introduction of greener products and components to the deployment of technological advances in development and engineering processes. In relation to both, sustainable automotive products as well as the deployment of technological advances, the integration of AI (Artificial Intelligence) approaches in combination with virtual products in automotive development and engineering processes is of great importance. In combination with knowledge-based CAx (Computer-Aided engineering), the integration of AI approaches delivers an enormous potential to enhance automotive development processes. In addition to process optimizations, the integration of various AI approaches considers sustainability (e.g., optimization of component geometries and materials, reduction of emissions over the entire life cycle, CO2reduction through improved development) and economical aspects (e.g., resources savings throughout the entire development process, time and cost savings through earlier error detection, avoidance of unnecessary process steps). The present approach deals with the integration of AI and knowledge-based engineering methods in the early phases of automotive development and engineering processes. Furthermore, the paper points to the time, cost and resources reduction potential, leading to earlier market entries and a greener industry. Finally, the paper demonstrates the integration of AI technologies into industrial development and engineering processes based on selected application scenarios.

In the reliability literature, there are completely different representations for two of the most common graphs: the graph that expresses the failure rate over the life of a product (bathtub curve) and the one that graphically identifies the Weibull triparametric model (linear regression of the Weibull curve using the Allan-Plaît graph). Even if the identification of the Weibull model is no longer done graphically, but with the help of dedicated calculation programs, the mathematical bases of the linearization of the F(t) fault distribution function by logarithm remain equally important. The present paper aims to establish which of the graphic variants are the correct ones and to identify the causes that led to the incorrect graphic representations. Based on an extensive theoretical documentation (analysis of numerous works in the field of reliability, published over the last decades, in the country and abroad) it is concluded that in foreign literature these graphs are always correct and that they were taken correctly in Romanian works from the 70’s to the 80’s of the last century, but starting with the 90’s there are fundamentally different representations, especially in the field of reliability engineering. Finally, the causes that led to these non-compliant graphical representations are identified. As these misrepresentations seem to persist, this paper is intended to be a signal of this issue.

Nowadays, the chassis represents the most important structural part of the vehicle, that has a great influence on the passenger’s safety. Lately, topology optimization represents a vital part of the automotive design process. The chassis design can improve the stability and rigidity of the vehicle for accurate handling. In this paper is presented the conceptual design of an EV (electric vehicle) chassis generated by using the topology optimization method. The introduction of the paper presents the latest method used in automotive optimization and the theoretical aspects. In the second part, the basic chassis structure is modelled using CAD software. The objective of this optimization study is to decrease the mass of the chassis to a minimum, without affecting the mechanical properties. Two optimization cases are studied using the steel and aluminium allow material at different boundary conditions. At the final of this research, all results are compared, and the conclusions are presented.

In recent development of goods transportation by road, there has been a growing interest in truck aerodynamics as a consequence of increased desire to reduce fuel consumption and emissions. Commercial vehicles have undergone continuous modifications in terms of body design (cabin) and trailers or semi-trailers. There have been and still are areas that disrupt air flow and can be optimized for an improved aerodynamic performance. As part of this areas, the paper will study the influence of beacon lights and light ramps positioned on cabin roof for European type trucks (tractor units). These warning equipment’s are imposed by transportation laws, reason for which eliminating them for achieving described purpose is not an option. In this context, the reduction of aerodynamic coefficient (Cd) can be pursued by analysing and optimizing the dimensions, shape and position for warning lights, in order to reduce the magnitude level of swirling effect. Different configurations of these elements will be tested and their impact in terms of air flow on the truck body will be analysed, with focus on roof area. The study will be done by simulating the interaction between airflow and truck in a virtual aerodynamic wind tunnel. The results will be analysed with the help of parameters like velocities, streamlines and pressures from a theoretical and experimental point of view to find the most viable option for each of the presented elements. The CFD (computational fluid dynamics) numerical simulations for chosen tests will be performed at a speed of 110 km/h considering that it is an often-encountered speed for trucks and also that aerodynamic phenomenology can be BETTER observed. By analysing the results obtained from the performed CFD simulations, the best positions and shapes for the beacon and ramp lights are desired to be identified. The paper conclusions will contain best configurations of warning lights and emissions improvement.

The fast growth of Internet applications brings with it new challenges for researchers to provide new solutions that guarantee better Internet access for mobile hosts and networks. The globally reachable, Home-Agent based, infrastructure Network Mobility (NEMO) and the local, multi-hop, and infrastructure-less Mobile Ad hoc Network (MANET) developed by Internet Engineering Task Force (IETF) support different topologies of the mobile networks. A new architecture was proposed by combining both topologies to obtain Mobile Ad Hoc NEMO (MANEMO). However, the integration of NEMO and MANET introduces many challenges such as network loops, sub-optimal route, redundant tunnel problem, absence of communication without Home Agent reachability, and exit router selection when multiple Exit Routers to the Internet exist. This paper aims to review the different proposed models that could be used to implement the gateway selection mechanism and it highlights the strengths as well as the limitations of these approaches.

Four different fractions of phosphogypsum were characterized by several analytical techniques. The size and shape of particles were determined by scanning electron microscopy. Analyses of infrared spectroscopy and X-ray diffraction have shown that these particles are mainly composed of calcium sulfate more or less hydrated. Calcination tests were carried out showed that treatment of these powders at 600degC for one hour increase their initial britghtness to values high enough to be used as a filler in paper.

Underground utility refers to any below-ground line, installation, or structure used by a service or utility provider. Underground utility inspection is a process of examining the designated area that needs to be inspected in detail. The purpose of the inspection is to ensure that the underground utility is in good condition and to check for any faults. By using the ground penetrating radar (GPR), the technology can capture images below the surface of the ground using radio waves. The various data through previous references are used to discuss and analyse the capability of GPR for underground utility inspection to ensure its gives the best performance for the inspection. GPR technology has become an essential tool for locating buried utilities and preventing damage and accidents during construction projects. This paper explores various advancements in GPR technology, including data processing methods and scanning techniques, to improve the accuracy and effectiveness of underground utility mapping. The research presented in this paper highlights the abilities of GPR to inspect underground utilities. The GPR data used in this project was collected from the evaluation and verification facility (EVF) in the Malaysia Nuclear Agency. The accuracy of these predicted positions was validated from GPR data and compared with as-built drawings from the contractor. The alternative analysis approaches that could be applied to improve the GPR accuracy when the optimum conditions are not met are also discussed.

In this paper, we present a radiation detector module that can be seamlessly integrated with Robot Operating System (ROS) to enable robots to perform radiation measurements in hazardous environments. The module is designed with a detector PCB and connectors that are compatible with an Arduino shield. The Arduino firmware is programmed with a counter-timer algorithm and publishes data to the ROS environment, allowing for easy visualization of the data in a 2D occupancy map. Our experimental results demonstrate the module’s effectiveness in inspecting and reconstructing the robot’s path during operations. This paper provides a valuable contribution to the field of robotics by enabling robots to perform radiation measurements safely and accurately in dangerous environments.

The paper aims to investigate some important thermal effects that could affect the Additive Manufacturing (AM) process of Laser Powder Bed Fusion. This analysis starts with investigating the variation of the material substrate temperature due to a variation of the Interlayer Cooling-Time (ILCT); then, the paper analyzes the effect of Preheating temperature on the material microstructure of the first building layers. Finally, we assess the effect of variation in gas flow speed as a function of part position on the building platform. In addition, in this work, the previously mentioned thermal aspects are evaluated in detail under particular geometrical and printing conditions considered the most critical for the L-PBF process. All cases studied are performed on IN718 superalloy specimens. In particular, for ILCT investigation, 60 microns layered specimens are printed for Preheating temperature analysis 40 and 60 layered specimens and for gas flow speed evaluation 40 microns one. All the results are evaluated through a porosity and melt pool analysis. The results obtained in this work highlight a critical range for low ILCT, 2-6 seconds, for part integrity that could be affected by overheating effects. To avoid this criticality, inserting ghost parts during the printing or reducing the laser power value is suggested. Concerning the preheating temperature effect, the first 1.2 mm of printed layers are found to be critical and affected by melt pool instability. In this case, a sacrificial substrate used in the first layers could save the quality of a few layers height part. The gas flow analysis highlights how some areas of the building platform are affected by particular thermal conditions negatively influencing material printability. To minimize this issue as much as possible, modify the job layout to avoid printing parts in the critical zones.

Cryogenic power electronic conversion (< 123 K) is expected to offer higher efficiencies for future all-electric transportation platforms. Low temperature operation of converters together with integration of wide bandgap devices (WBG) can enable higher switching frequencies with reduced filtering components. This paper briefly reviews the passive components involved in the development of a cryogenic converter. The paper also reviews in detail the converter development with WBG devices by far, and provides a discussion on benefits achieved, and challenges in terms of auxiliary components and measurements. The last part of the paper gives a discussion on envisioned challenges, and different research directions for future superconducting power conversion systems.

All papers published in this volume have been peer reviewed through processes administered by the Editors. Reviews (2 required per paper) were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

Prior to the invention of the vacuum flask by James Dewar in 1895, cryogenic temperatures below 100 K could not be sustained very long. The Development of the modern cryostat was an extension of the basic Dewar vacuum flask. The design of the cryostat, its insulation, and the cold mass support system is a function of the cryostat’s intended use. The type of refrigeration available also influenced the development insulation systems, support systems, transfer lines and electrical leads that are part of the cryostat. In recent years the availability and the cost of helium has been a significant factor in cryostat design and the methods used to cool and cool-down cryostats. This paper explores the historical development of today’s cryostats and how that can be tied to the source of cryogenic cooling. This paper is focused on earth bound cryostats. Some of the same principles can be applied cryostats used in space.

Exergy analysis was applied to the evaluation of helium internal purifier in this paper. The important operating parameters has been given to determine the exergy destructions in components as well as in the entire cycle of internal purifier. The analysis results show that the recovery of liquefied air energy can improve the performance of purifier and the exergy destruction of different heat exchanger is different. Results from the analysis helped evolving guidelines for designing appropriate technological process for practical helium internal purifier. An internal purifier with an optimized structure was designed to remove air impurities up to 10 mol%, beyond previous maximum impurity content. The impact on liquefaction capacity is minimized because of the small consumption of cold flow. The achievable performance was also provided in this paper. The purifier could remove air impurities up to 8 mol%.

This paper investigates how numerical modelling can be used to explore thermoacoustic machines and compares the accuracy of the performance predictions for different simulation software. The software used includes one designed for modelling Stirling machines called ‘Sage’ and for modelling thermoacoustic machines called ‘DeltaEC.’ To compare their results, a model of both a thermoacoustic Stirling engine and refrigerator were developed from existing models in published papers, which contained experimental data to validate the numerical models. Overall, it was found that although both can accurately model thermoacoustic machines, they present different optimal conditions, and Sage’s solving method makes it more complex to model the standing wave.

This paper is aimed at studying and improving the phenomenon of pressure degradation in a helium cryogenic system. There are two 450W helium cryogenic systems for the Taiwan light source (TLS) and one 890W helium cryogenic system for the Taiwan photon source (TPS) housed at the National Synchrotron Radiation Research Center (NSRRC). The TLS helium cryogenic system is used for one superconducting radio frequency (SRF) cavity and five superconducting magnets. The TPS helium cryogenic system is used for two SRF cavities at the present stage. These three helium cryogenic systems have experienced pressure degradation, which reduced their performance and increased liquid nitrogen consumption for precooling over the past few years. A cryogenic adsorber was set up in an effort to capture the impurities, but this made no difference for pressure degradation in the system. The impurities were comprised of not only gas but also moisture. It was found that the cryogenic adsorber was not efficient enough to remove the moisture. This paper presents the study for the phenomena of pressure degradation. A moisture removal system was designed which is also discussed.

NASA is considering a “probe” class mission with a far-infrared imaging and spectroscopy space telescope. A critical technology need for this mission is an efficient, high capacity, low-temperature cryocooler with low exported vibrations to enable its cryogenic instruments to achieve exquisite sensitivity and low internal noise to observe far distant faint cosmic sources. This paper discusses the design of a 4.5 K hybrid cooler consisting of a pulse tube precooler and a JT stage. The JT stage uses 3He as its working fluid to achieve a low cooling temperature of 4.5 K. The cooler will build on the JWST MIRI spare flight cooler, using existing TRL 9 component and subsystem hardware technologies. The paper will discuss the cooler configuration, thermodynamic design, predicted performance, and sensitivity to operating conditions. The impact of pressure drops and thermal ineffectiveness in the JT stage recuperators are discussed and compared to those in the MIRI cooler. Finally, test results for MIRI Development Model (DM) compressor with 4He are presented. Test data include compressor volumetric flow rates and power inputs at different pressure ratios and piston stroke lengths. The DM compressor test results and flight compressor test data collected during MIRI spare flight cooler acceptance testing both indicate that the 4.5 K cooler will be able to meet the cooling requirement of 48 mW at 4.5 K and 230 mW at 18 K with a significant margin.

Recent helium shortages and helium price increases have lead to an increased emphasis being placed on conserving helium. The need to conserve helium must be balanced with need to maintain the high levels of purity necessary to prevent operational problems caused by contamination. Helium losses and contamination control are especially important for test stands that have cryogenic distribution systems operating continuously with frequent changeover of cryogenic temperature components that are being tested. This paper describes a mathematical model to estimate the quantity of helium lost and the purity of the helium after the pump and backfill procedure is complete. The process to determine the optimal time during pump down to cut off pumping and start backfilling is described. There is a tradeoff between trying to achieve the lowest possible pressure during pumping and the quantity of air leaking into the volume while pumping is occurring. An additional benefit of careful selection of pump and backfill parameters in conjunction with real-time pressure monitoring can reduce the labor and time required to complete a successful pump and backfill procedure. This paper is intended to be a tool for engineers to review their pump and backfill procedures and measured data to optimize helium losses, system purity, and labor required.

The need to decrease the gross weight of cryogenic hydrogen fuel systems in future zero emission mobility leads to increasing activities in the field of cryogenic lightweight engineering. Fibre reinforced thermoplastic composite materials (FRT) are considered for cryogenic applications despite their bias towards permeation. However, permeation through plastic materials is of major concern in cryogenic applications. Even tiny fluxes can very much compromise the insulating power of high vacuum spaces required for insulation of cryogenic systems such as tank structures or transfer lines. Hence, it is essential to qualify those FRT in terms of their hydrogen permeability for future usage in mobile cryogenic applications. The conventional concepts for measuring permeability in plastic materials are not sufficient for cryogenic measurements of FRT as shown in a previous paper. For that, a novel laboratory test rig concept was proposed. In this paper, we validate this concept and show its eligibility for measuring permeation of hydrogen through thermoplastic materials. Therefore, we report results of helium permeation through polytetrafluoroethylene (PTFE) at room temperature and compare those results to literature permeability data.

Liquid hydrogen cold-chain logistics vehicle (LHCCLV) is a special vehicle using liquid hydrogen (LH2) as the source of both power and cold energy. A significant weakness of LH2 is its high energy consumption during the hydrogen liquefaction process, thus the utilization of cold energy in LHCCLV can improve the economic performance and competitiveness of LH2. Because of the high energy storage density of LH2 and the relatively high efficiency of fuel cells, we find that cold energy can not meet the demand of LHCCLV. Therefore, we consider enlarging the cold energy by efforts including the para-ortho hydrogen conversion (POC), whose reverse reaction consumes an energy level exceeding 20% during the hydrogen liquefaction process. In this paper, numerical models of discharging hydrogen from the LH2 and subcooling hydrogen tank are established, and the influence of POC and other efforts on the supply of cold energy is analyzed. The changes in instantaneous and total cold energy supply under different working conditions are analyzed, and the important influence of POC and other efforts is confirmed. The beneficial effect of POC is quantified in the paper, especially for the cold energy supply. This paper provides an essential reference for the research and development of LHCCLV. Also, it guides the comprehensive utilization of cold energy in other situations to promote the improvement of the economy of hydrogen energy utilization routes in the form of LH2.

In this paper, the results of a nitrogen-based pulsating heat pipe (PHP) with the ability to change the number of turns are presented. The experiment assembly consists of two identical PHP subsections with their own fill lines. The length of the condenser, the adiabatic section, and the evaporator section of each PHP are 90mm, 1000mm, and 60mm respectively. Because of the unique design of the condenser section of the PHP, it can change the configuration into 1-turn, 3-turn, 5-turn, and 7-turn PHP. The PHP was tested at the condenser temperatures 77.4K, and 84.5K, which are at, and above the boiling point of the liquid nitrogen at ambient pressure. At each condenser temperature, the PHP was tested at three different initial fill ratios (50%, 63%, and 75%). The experimental results and analysis for the 1-turn setup of this nitrogen-based PHP assembly are presented in this paper.

All papers published in this volume have been peer reviewed through processes administered by the Editors. Reviews (2 required per paper) were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

The European Academic Symposium on EAF Steelmaking (EASES) is a series of events targeted at researchers and doctoral candidates working with different aspects of electric arc furnace (EAF) steelmaking. Previously, four events were organised in 2015, 2016, 2018, and 2021 in Aachen, Germany. The 5th European Academic Symposium on EAF Steelmaking (EASES 2023) was organised jointly by the RWTH Aachen University (Department for Industrial Furnaces and Heat Engineering) and University of Oulu (Process Metallurgy Research Unit) and held at the University of Oulu in Oulu, Finland on 5-7 June 2023. A total of 29 presentations were held at the event, out of which 13 featured an accompanying full paper. After the symposium, the authors of the full papers were invited to submit their manuscripts to be included in the proceedings. The proceedings consist of a total of 12 peer-reviewed papers published in the IOP Conference Series: Materials Science and Engineering. Based on the presentations, the development of modelling and monitoring tools for process optimization, the use of biochar to replace fossil carbon for slag foaming, and the use of hydrogen as an alternative burner fuel were identified as current hot topics. In the future, the importance of the EAF process is expected to increase further due to the increasing availability of scrap and plans for ore-based production routes based on hydrogen direct reduction.

We present the experimental decomposition kinetics for the synthesis of metal oxide 2D nanosheets by the virtual substrate method. In this method, acetates of Mg and Cu were used as precursors for the growth of prototype MgO and CuO nanosheets, while the filter paper was utilized as a virtual substrate. The synthesized samples were characterized by X-ray diffraction for the phase analysis of the nanostructures, which confirms the cubic phase of MgO and monoclinic phase of CuO; with a minor Cu2O phase. Field emission scanning electron microscopy was used to determine the surface morphology of the nanosheets. Fourier transform infrared spectroscopy was utilized to identify the vibrational modes of the metal oxides and the functional groups present in the sample. Thermogravimetric analysis revealed the evolution of combustive oxidation of filter paper with the thermal decomposition of acetates situated on its surface.

Designing modern control systems is a critical factor in producing rigid control and effective performance of non-linear and complex systems—particularly employing intelligence-based controllers, derived from soft computing algorithms. It is known to be well capable of exploiting tolerances for uncertainty and nonlinearity. Fuzzy logic, which utilizes soft computing techniques, deals with vague information and approximate reasoning, yet it lacks effective learning capability, while ANN is known for exceptional learning and adaptation of training data. Adaptive neuro-fuzzy interference system (ANFIS), a hybrid of these two algorithms, is a fuzzy interference system optimized by neural networks. Most nuclear generating stations still use PID controllers, which does not show good controlling capabilities, resulting in large coolant level overshoot and longer settling time. This paper bridges this gap by testing an ANFIS approach that yields high predictive and control capability. In validating the configured control loop model, three loss-of-load transients from a Shippingport reactor were tested, trained and demonstrated using the simulations in the MATLAB/Simulink environment. The minimal training RMSE for the 51 MW(e), 74 MW(e), and 105 MW(e) loss-of-load transients are 18.85%, 19.37%, and 24.36%. The pressure response showed ideal output, with all three steady-state pressures close at setpoint (14 MPa), proving that the ANFIS controller is well capable of rejecting disturbances with lesser overshoot and faster settling times in maintaining level setpoint. Validating solely the pressurizer model was executed in a turbine leading power trip from a 100% to 75% reduction range in PCTRAN, a pressurized water reactor (PWR) simulator made available by IAEA. The comparative performance exhibited a good fit between the reported simulation data and model data. Both results against simulation and experimental transients captured the effective predictive and control capabilities of the pressurizer unit and control system.

Rare earth elements (REE) play an integral part of modern life, from smartphones to satellites. Dubbed ‘critical metals’, the demand for REE has significantly increased, driven by the growth in global production for green technologies such as e-vehicles, solar panels, wind turbines, and other energy-economic infrastructure. Therefore, there is a need to explore alternative REE sources to ensure continued development of emerging green technologies. A possible alternative REE source is bauxite, which is soil that forms from intense weathering of aluminum oxide-rich rocks exposed to tropical climate. This paper investigates the REE enrichment and extraction potential from bauxite deposits in Paranas, Samar, Philippines. The sampling survey included collection of rock and soil on surface exposures, test pits, and drill cores from accessible portions of the bauxite mineral reservation site. The soil and parent rock samples collected were then subjected to various geochemical and mineralogical analyses. The main ore minerals of aluminum are gibbsite and boehmite; with minor goethite, hematite, and magnetite. Investigation of the geochemical composition of the bauxite reveals a total REE content of up to ~300 ppm, which is one of the highest REE and critical metal content among geological deposits in the country. These results will provide inputs in the design of a green and economical process to recover REE from bauxites. If the bauxite deposits prove to be a valuable REE resource, this study will help maximize the economic potential of the mineral resource in the Philippines and contribute to an economically efficient and environment-friendly way to produce e-tech elements for the country.

All papers published in this volume have been reviewed through processes administered by the Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

This paper introduces a novel quantitative structure-activity relationship (QSAR) system for predicting the biodegradability of chemicals. The system focuses on evaluating the ratio of biochemical oxygen demand (BOD) to theoretical oxygen demand (ThOD) (%BOD/ThOD) and the presence of degradation products to categorize chemicals as “readily biodegradable” (RB) or “not readily biodegradable” (NB). The conventional laboratory testing method for biodegradability assessment is time-consuming and expensive, thus highlighting the need for a quantitative structure-activity relationship (QSAR) system that can predict biodegradability without the need for extensive testing. The authors acquired a dataset of 3948 chemicals from the National Institute of Technology and Evaluation (NITE) database, which included information on molecular structure, %BOD/ThOD values, and the presence of degradation products. The QSAR system consists of two prediction models: a %BOD/ThOD prediction model and a discrimination prediction model. Multiple algorithms were employed in each model to enhance prediction accuracy. The %BOD/ThOD prediction model utilizes eight algorithms, including linear, nonlinear, and tree-structured models. The discrimination prediction model employs ten algorithms, and the outcomes are combined using majority voting. Explanatory variables for both models include molecular descriptors and spatial structure derived from the chemical’s molecular representation. The performance of the QSAR system was evaluated based on training and validation datasets. Results showed that the combination of three %BOD/ThOD prediction algorithms improved the average correction rate compared to using all algorithms. Similarly, selecting the discrimination prediction algorithm further enhanced the average correction rate.

Cellulose from macroalgae is potential for the extraction of nanomaterials due to its availability and its great fraction in the biomass. Cladophora rupestrisis a macroalgae and is a good material to which a cellulose may be extracted. The said macroalgae has no value-added products or uses yet. It has a lignocellulosic profile of: alpha-cellulose, 33.43 %; hemicellulose, 15.48%; holocellulose, 48.93; acid soluble lignin, 2.22%; acid insoluble lignin, 22.33%, extractives, 5.67% and total ash, 39.65%. Identifying the best method and conditions for the extraction of cellulose from the said material is a challenge that needs to be addressed. The process for the cellulose extraction considered variations on drying (oven, air, and sun drying), defatting (using solvents: methanol and hexane; and extraction time: 8 hrs and 4 days), solvent drying (oven and air drying), alkaline pre-treatment (0.1, 0.5, and 1M NaOH), fixed conditions on bleaching, bleached biomass oven drying. The biomass weight losses were monitored for some steps, attributing this on the removal of the lignin and extractives. The lignocellulosic profile of the crude cellulose extracted from the macroalgae using the best conditions was determined indicating an increased fraction of the cellulose components in the biomass and a transformation of the rigid biomass into a soft and paper-like texture. The functional groups present on the cellulose was determined. The extracted cellulose was used to produced cellulose nanofibril (CNF) with fiber diameter of the CNF ranges on 14.29 – 37.50 nm and crystallinity index of 92.48%. Attempts were done on extraction of cellulose nanocrystal (CNC) utilizing microwave-assisted acid hydrolysis (MAAH) and semi-batch acid hydrolysis (SBAH); and variation on the acid used (sulfuric acid, and oxalic acid), concentration of the acid, and the temperature conditions.

The paper presents the results from a study of the corrosion behaviour of different metallic materials, such as copper, aluminium and OL 52 steel in the presences of various concentrations of citric acid added in neutral solution (Na2SO4 0.25 M).

The tire is one of the most complex components of the vehicle, which justifies strict standards and regulations set by governments worldwide to ensure the performance, durability, and reliability of tires approved for use in the transport sector. Among these requirements, tire durability testing involves the assessment of short-and long-term tire response to determine optimum conditions of use and service life. Therefore, this paper focuses on the creep performance of tires using the finite element method in ABAQUS. As a case study, a selected tire with visco-hyperelastic rubber compounds and linear elastic reinforcements is subjected to a constant prescribed force for a period of time, and the resulting strain evolution is recorded till the release of the applied load. Several parameters are accounted for, such as the inflation pressure, material characteristic times, and load amplitude. The post-processing of results enabled the prediction of the overall creep response of the tire over time with respect to the prescribed load. The knowledge gained in this study can be exploited to predict tire failure caused by excessive strain and pinpoint the areas of the tire that are the most exposed to creep failure.

Additive manufacturing is in continuous development, and the obtained components still have some shortcomings. The vast majority of mechanical characterizations are performed on polymer materials, using in particular the material extrusion process, while metallic components face not negligible deficiencies. This paper presents an experimental investigation of the vibration behaviour of selective laser melting (SLM) 3D printed specimens. The specimens were printed “on-edge” from AlSi10Mg aluminium alloys and subjected to fatigue tests. By using an electrodynamic shaker, controller, acceleration transducer, and laser vibrometer, the tests have been performed and the data analysed. After the tests, a correlation was obtained by using a finite element analysis (FEA). The damping coefficients (alpha and beta) are obtained from the experimental data. These coefficients are then used to check the accuracy of each FEA model. The results reveal the correlation between structural damping and anisotropy of additive manufacturing specimens, and their impact on high-cycle fatigue performance.

This paper examined the influence of the sulfite concentration introduced in the electrolyte added to the neutral solution (1 mol L-1 Na2SO4) on the corrosion process of 304L stainless steel material. 304L. The accelerated effect of sulfite ions under corrosion rate of 304L austenitic stainless steel was demonstrated using electrochemical techniques such as linear sweep voltammetry at a low scan rate −1 mV s−1, the Tafel slope method, chronoamperometry, and electrochemical impedance spectroscopy. Electrochemical studies were conducted using a BioLogic SP150 potentiostat/galvanostat.