Factorial Plan Research Articles

THE INFLUENCE OF THE ELECTRODE TYPES ON THE CARBON MONOXIDE FORMATION DURING THE WELDING PROCESS

A study on the dependence of the carbon monoxide concentration in the working area on the magnitude of the welding current and welding time while using electrodes of different types was conducted in order to choose the methods and means for the protection of welders. An analysis of the latest research and publications on air pollution in the working area by aerosols and gases generated during arc welding was performed. For the experimental determination of carbon monoxide concentrations in the welding area, an individual gas detector-analyzer was used. The research results conducted during arc welding in laboratory conditions using the full factorial planning of the FFE2 type experiment are presented. Based on the obtained regression models, graphical dependences of carbon monoxide concentration in the working area on the welding current and welding time were constructed when using the most common brands of electrodes. It was established that the largest amount of carbon monoxide is formed during welding at a current of 200 A with electrodes having a rutile-cellulose coating, in second place - with electrodes having a basic coating, and in third place - having rutile coating; after 5 minutes of welding with an electric current of 100 A, a larger amount of this gas is formed when using the electrodes having the basic coating. The obtained dependences make it possible to practically choose welding modes that ensure minimum levels of carbon monoxide emissions. A complex of modern solutions for reducing air pollution in the working area with carbon monoxide is given, which consists in the use of neutralization methods, ventilation means, and the use of appropriate means of individual respiratory protection, as well as controlling the air environment state during work.

A Cost/Benefit and Flexibility Evaluation Framework for Additive Technologies in Strategic Factory Planning

There is a growing demand for more flexibility in manufacturing to counter the volatility and unpredictability of the markets and provide more individualization for customers. However, the design and implementation of flexibility within manufacturing systems are costly and only economically viable if applicable to actual demand fluctuations. To this end, companies are considering additive manufacturing (AM) to make production more flexible. This paper develops a conceptual model for the impact quantification of AM on volume and mix flexibility within production systems in the early stages of the factory-planning process. Together with the model, an application guideline is presented to help planners with the flexibility quantification and the factory design process. Following the development of the model and guideline, a case study is presented to indicate the potential impact additive technologies can have on manufacturing flexibility Within the case study, various scenarios with different production system configurations and production programs are analyzed, and the impact of the additive technologies on volume and mix flexibility is calculated. This work will allow factory planners to determine the potential impacts of AM on manufacturing flexibility in an early planning stage and design their production systems accordingly.

A Basic Description Logic for Service-Oriented Architecture in Factory Planning and Operational Control in the Age of Industry 4.0

Manufacturing companies across multiple industries face an increasingly dynamic and unpredictable environment. This development can be seen on both the market and supply side. To respond to these challenges, manufacturing companies must implement smart manufacturing systems and become more flexible and agile. The flexibility in operational planning regarding the scheduling and sequencing of customer orders needs to be increased and new structures must be implemented in manufacturing systems’ fundamental design as they constitute much of the operational flexibility available. To this end, smart and more flexible solutions for production planning and control (PPC) are developed. However, scheduling or sequencing is often only considered isolated in a predefined stable environment. Moreover, their orientation on the fundamental logic of the existing IT solutions and their applicability in a dynamic environment is limited. This paper presents a conceptual model for a task-based description logic that can be applied to factory planning, technology planning, and operational control. By using service-oriented architectures, the goal is to generate smart manufacturing systems. The logic is designed to allow for easy and automated maintenance. It is compatible with the existing resource and process allocation logic across operational and strategic factory and production planning.

Evaluation of process planning in manufacturing by a neural network based on an energy definition of hopfield nets

During the planning stages of new factories for the Body-In-White assembly, the processes used per production system need to be defined. Each production system uses a specific combination of processes, with each process belonging to a main process group. The combination of the processes and groups is subject to restrictions. Since the amount of possible combinations is too large to individually check for restrictions, we propose a Neural Network using an energy measurement derived from Hopfield networks. The proposed network memorizes former correct combinations and provides a recommendation score on how likely a new planned configuration is. Since processes can be paired with processes from their own group or with themselves, the Neural Network is modified to allow loops for joining vertices with themselves. This modification is achieved by adjusting the energy function of Hopfield networks to measure the activation of the combinations of clusters, meaning the edges, and not the activation of vertices during the training phase. We implemented the network for the process planning of factories of a leading European automotive manufacturer, and the results using correct, incorrect, and random process combinations indicate a strong capability of detecting anomalous process combinations.

Effect of printing strategies on the properties of product in selective Sorel cement activation

PurposeParticles bed binding by selective cement activation (SCA) method is a computer-aided manufacturing (CAM) technique used to produce cementitious elements. A computer-aided design file is sliced to generate G-codes before printing. This paper aims to study the effect of key input parameters for slicer software on the final properties of printed products.Design/methodology/approachThe one factor at a time (OFAT) methodology is used to investigate the impact of selected parameters on the final properties of printed specimens, and the causes for the variations in outcomes of each variable are discussed.FindingsFiner aggregates can generate a more compact layer, resulting in a denser product with higher strength. Fluid pressure is directly determined by voxel rate (rV); however, high pressures enable better fluid penetration control for fortified products; for extreme rVs, residual voids in the interfaces between successive layers and single-line primitives impair mechanical strength. It was understood that printhead movement along the orientation of the parts in the powder bed improved the mechanical properties.Originality/valueThe design of experiment (DOE) method assesses the influence of process parameters on various input printing variables at the same time. As the resources are limited, a fractional factorial plan is carried out on a subset of a full factorial design; hence, providing physical interpretation behind changes in each factor is difficult. OFAT aids in analyzing the effect of a change in one factor on output while all other parameters are kept constant. The results assist engineers in properly considering the influence of variable variations for future DOE designs.

Calculation of the stress-strain state of the "pipe-composite wrap" system

This study focuses on the application of composite materials for strengthening and repairing worn pipelines. The influence of various structural and operational factors on the stress state of a pipe reinforced with a composite wrap was investigated. A comparative analysis was conducted between the calculations of a steel pipe reinforced with a composite using the finite element method and several analytical methods, including those specified in DSTU ISO 24817:2019. Numerical and analytical calculations were carried out according to a full factorial experiment plan (three factors at three levels, twenty-seven experiments in total), with the variable factors being the wrap thickness, pipe thickness, and the ratio of residual thickness to pipe thickness. The calculations involved two system variants: "undamaged pipe" and "damaged pipe." A new analytical approach was proposed to determine the stress-strain state of the "pipe-composite wrap" system, which provides higher accuracy compared to DSTU ISO 24817:2019.

Characteristics of Aloe-buni Powdered Drinks with the Addition of Arabic Gum and Drying Temperature Variations

Aloe-buni is a functional drink of Aloe vera gel and buni fruit extract, containing fiber and antioxidants that are beneficial to health. Processing of Aloe-buni powder drinks using the foam mat drying method requires arabic gum filler to form powder. The drying temperature also greatly affects the manufacture of powdered drinks. The purpose of this study was to determine the effect of gum arabic concentration and drying temperature on the characteristics of Aloe-buni powdered drink. This study used a two-factor factorial plan, namely the concentration of arabic gum filler material 10%, 20%, 30% and drying temperature consisting of 30°C, 40°C and 50°C. The results showed that the concentration of gum arabic and the drying temperature were different from the characteristics of the Aloe-buni powdered drink. The best characteristics of Aloe-buni powdered drink were obtained of a concentration 30% arabic gum and a heating temperature of 40°C, as for a pH value of 4.30; total dissolve solid 41.33°Brix; color a* 4.86; moisture content 5.61%; solubility 98.56%; antioxidant activity 7.46%; and vitamin C 66.06 mg/100g.

Strategi Perencanaan Bisnis Teaching Factory Dalam Meningkatkan Kemampuan Entrepreneurship Siswa Melalui SWOT (Studi Kasus SMK Darut Taqwa Purwosari Kab. Pasuruan)

This study aims to develop a Teaching Factory planning strategy to enhance the entrepreneurship skills of students at SMK Darut Taqwa. The SWOT analysis method was used in this study, with data collected through observation, interviews, and literature review. The SWOT analysis results indicate that Teaching Factory can strengthen the relationship with stakeholders and the community, and provide opportunities for students to develop entrepreneurship skills and insights. However, there are several limitations and weaknesses in implementing this strategy, such as limited resources and a lack of technology and digital platforms to support student entrepreneurship development. To address these issues, this study recommends several strategies, such as developing entrepreneurship training programs for students, identifying new resources to support student entrepreneurship development, and utilizing technology and digital platforms to support student entrepreneurship development. These strategies can help SMK students develop the necessary entrepreneurship skills and insights to compete with established businesses in the market. It is hoped that the results of this study can serve as a reference for educational institutions and the government in planning effective and sustainable entrepreneurship learning programs in the future.

Retrofitting passive cooling strategies to combat heat stress in the face of climate change: A case study of a ready-made garment factory in Dhaka, Bangladesh.

The ready-made garment industry is critical to the Bangladesh economy. There is an urgent need to improve current working conditions and build capacity for heat mitigation as conditions worsen due to climate change. We modelled a typical, mid-sized, non-air-conditioned factory in Bangladesh and simulated how the indoor thermal environment is altered by four rooftop retrofits (1. extensive green roof, 2. rooftop shading, 3. white cool roof, 4. insulated white cool roof) on present-day and future decades under different climate scenarios. Simulations showed that all strategies reduce indoor air temperatures by around 2 °C on average and reduce the number of present-day annual work-hours during which wetbulb globe temperature exceeds the standardised limits for moderate work rates by up to 603 h - the equivalent of 75 (8 h) working days per year. By 2050 under a high-emissions scenario, indoor conditions with a rooftop intervention are comparable to present-day conditions. To reduce the growing need for carbon-intensive air-conditioning, sustainable heat mitigation strategies need to be incorporated into a wider range of solutions at the individual, building, and urban level. The results presented here have implications for factory planning and retrofit design, and may inform policies targeting worker health, well-being, and productivity.

Recovery of Platinum and Palladium from Spent Automotive Catalysts: Study of a New Leaching System Using a Complete Factorial Design

The recovery of materials and energy from end-of-life products is increasingly a fundamental factor in the sustainable development of various countries. Recovering metals from different types of waste is not only a practice in support of the environment, but is also a profitable economic activity. For this reason, exhausted automotive catalysts can become renewable sources of critical raw materials such as Pt, Pd, and Rh. However, recovering Pt and Pd from spent catalysts through an efficient, economical, and green method remains a challenge. This article presents a new leaching process for the hydrometallurgical recovery of Pt and Pd from exhausted automotive catalysts. The leaching solution consists of an aqueous mixture of hydrochloric acid, two organic acids (citric acid and acetic acid) and hydrogen peroxide. A complete factorial plan on two levels (2k) was performed in order to evaluate the main effects of the analyzed factors and their interactions. The factors that were presumed to be the most influential on the leaching of Pt and Pd were the concentrations of the different reagents and the reaction time. The optimal circumstances for achieving the largest recovery (over 80% Pt and 100% Pd) were achieved using the following conditions: a concentration of HCl of 5 M, a concentration of H2O2 of 10% wt./vol., a concentration of C2H4O2 of 10%vol./vol., and a reaction time of 3 h.

Energy audit of a sugarcane plant to find out the main energy saving opportunities

Sugar extraction from sugarcane/sugar-beet is an energy-intensive process, both thermal and electrical energies. However, there are numerous opportunities for energy efficiency improvements. A number of tests were conducted in an old sugarcane factory, including the boiler, electricity generation, process, and mill section, to better understand these opportunities. During four years, specific energy consumption was 16-28 GJ/ton of raw sugar. Measurements and calculations revealed that some equipment, e.g. shredder's steam turbine and some gearboxes, require extensive repairs. The second set of areas for improvement relates to proper operation, such as determining the boiler excess air (which results in an average 0.6% efficiency reduction) and factory planning (near 200 MWh per year). The third type of improvement is to modify or integrate new elements into the existing plant, like water storage tank insulation (3.8 MW) and switching from load-unload operation to drive control for instrumentation compressors (43 MWh). Bangladesh J. Sci. Ind. Res. 58(1), 09-18, 2023

Towards a Holistic Life Cycle Costing and Assessment of Factories: Qualitative Modeling of Interdependencies in Factory Systems

Modern factory planning requires a holistic perspective taking economic as well as environmental sustainability over the entire factory life cycle into account. As a complex socio-technical system, the factory life cycle consists of multiple life cycles of the inherent factory elements. A holistic understanding of the individual life cycles and their interdependencies is missing for both planning and operation of a factory. Therefore, the goal is to develop a system understanding about life cycle-oriented factory planning and to analyze the contribution of relevant factory elements to the sustainability of a factory. As a result, a knowledge base for life cycle costing and assessment of the entire factory is established using an impact path model. The qualitative model supports factory planners in deriving planning measures for the sustainable design of a factory and in determining data requirements for the quantitative evaluation of the economic and environmental sustainability of a factory. It shows that the production and logistics concepts essentially define the sustainability potential during planning, while the resulting life cycle behavior of the process facilities and workers is responsible for the majority of costs and environmental impacts of a factory. Factory planners must therefore become aware of the implications of planning decisions on factory operation when developing concepts in the future.

Substantiation of rational design factors of a metropolitan railway station without side railway platforms

This article presents the results of a study on the stress-strain state of a metropolitan railway station structure without side railway platforms during the construction of the upper arch of the middle station tunnel using in-situ reinforced concrete. The study was conducted using a systematic approach methodology based on a full factorial experiment plan, with subsequent processing of the calculation results using mathematical statistical methods and regression analysis to create a probabilistic-statistical model. The initial data for the analysis were obtained through numerical analysis using mathematical models and the finite element method in the Midas GTS NX program. Within the framework of the study, the design parameters of the metropolitan railway station that had the greatest impact on the stress-strain state of the station structure and the surrounding soil mass were identified. A multifactorial experiment was conducted based on the obtained data, involving the mathematical modeling of the «station lining — soil massif» system using the finite element method. The results of the modeling allowed for the assessment of the influence of the tunnel casing design factors on the stress-strain state of the «station lining — soil mass» system. Based on the results of the regression analysis, patterns of influence on the stress-strain state of the «station lining — soil mass» system were revealed. Relationships for determining the rational design factors of a metropolitan railway station without side railway platforms during the construction of the upper arch of the middle station tunnel using in-situ reinforced concrete were obtained, forming the basis of a probabilistic-statistical model of the system. The developed probabilistic-statistical model enables the prediction of the static performance of the metropolitan railway station structure without side railway platforms, and provides substantiation for the rational parameters of the station tunnel casing structural elements in the engineering-geological conditions of St. Petersburg.

Ozonation for oxidation and transformation of pharmaceuticals in Arroio Diluvio River in Southern Brazil

ABSTRACT Pharmaceuticals are often found in the water environment and are not completely degraded by conventional treatment processes. There are some techniques, such as advanced oxidative processes (AOPs), which can promote, in addition to the total removal of contaminants, their mineralization, transforming them into CO2 and water. Thus, the objective of this work was to evaluate the mineralization capacity of the emerging pollutants caffeine and ampicillin, present in a real aqueous matrix, through ozonation. Factorial planning was carried out by Central Composite Design (CCD) under the Response Surface Methodology (RSM). Water samples were collected from Arroio Dilúvio, a river that cuts through the city of Porto Alegre (RS – Brazil), which receives domestic, hospital, and industrial effluents in nature. The experiments were conducted from the analysis of the influence of pH, time, and ozone flow rate variables. The ozonation system consisted of an oxygen concentrator, an ozone generator, and a gas washer bottle. With removals of caffeine and ampicillin around 100 and 99.7%, respectively, a mineralization of 30.8% was also obtained under conditions of pH 8, with an applied ozone dosage of 830 mg.L−1. In this process, the gas phase concentration was at 16.7 mg.L−1 when applied to 200 mL sample for 10 minutes and ozone flow rate of 1 L.min−1. A linear relationship was observed between the real and predicted values, and it has been shown that the relationship of the residual plot confirmed a sufficient approximation of the method for the optimization process. Finally, the desirability function showed adequate operating conditions for the mineralization of compounds by ozonation. Therefore, it is considered that this technique is effective for the mineralization of the pharmaceuticals studied, and can be applied as a way of treating a contaminated real matrix.

Modelling of micro-electrochemical machining parameters used for machining of holes on copper plate

The electrochemical machining is a non-conventional machining process based on the electrolysis principle. It is used to machine various features on conducting engineering materials with the required accuracy and precision. So an attempt has been made to machine micro-holes on a 300 μm thick copper plate as an anode and a hollow stainless steel tool electrode of 250 μm diameter as the cathode. The machining operation is performed on the in-house developed micro-ECM experimental setup with controlled machining parameters voltage, concentration, and duty factor varied in three levels. A full factorial experimental plan is used to study the output responses material removal rate (MRR), radial overcut (ROC), circularity, and taper angle (TA). Later an adaptive neuro-fuzzy inference system (ANFIS) model has been developed and shown the effectiveness of the developed model in the paper. The Sugeno fuzzy model has been used in ANFIS to generate the fuzzy rules required for the model. Out of 27 experiments, 22 machining data are used for training the model, and the remaining 5 machining data are used for testing the developed model. The average error observed between the ANFIS predicted values and experimental values of MRR is 12.56%, circularity is 43.09%, ROC is 13%, and TA is 27.53%, respectively.

Concept for modeling and quantitative evaluation of life cycle dynamics in factory systems

Against the background of the climate crisis, fast innovation space in emerging technologies and the global competitive environment for manufacturing companies, a sound understanding of the life cycle behavior of factory systems becomes more and more important. The decision context of the factory life cycle conveys a high level of complexity, e.g. by the heterogeneous nature of factory element life cycles, manifold interactions between them as well as external change drivers. A model-based understanding as well as methods and tools are required that support factory planners and operators in this regard. This paper presents an approach for the modeling and quantitative evaluation of life cycle dynamics in factory systems while respecting the dynamic behavior of factory operation, as well. The purpose of the modeling is to deepen the knowledge of the prevailing life cycle mechanisms and their implications for factory planning and operation. The application of the approach is demonstrated in an exemplary case study.

Effect of the Position in the Build Chamber on the Fatigue Strength of Additively Manufactured Maraging Steel MS1

The quality of additively produced parts and the achievable mechanical response may be affected by several factors, such as build orientation, heat treatment, or machining. A further rarely investigated factor is the position of the built part in the chamber with respect to inert gas flow. Previous studies have highlighted that the interaction between gas flow and laser track may induce an intense vaporization with consequent lack of fusion, particle entrainment, drop in density and denudation of the produced part, which is likely to detrimentally affect mechanical properties. This study addresses the effect of part position on the fatigue strength of heat-treated maraging steel MS1 produced by an EOSINT M280 machine in a nitrogen environment. Novelty arises from the lack of studies in this field, especially under fatigue. A factorial plan with subsequent statistical analysis highlighted that positioning the part upstream with respect to the gas flow leads to a slightly lower fatigue strength; however, no significant differences are observed. The failure mode, involving initiation from subsurface porosities of the same size, is also unaffected. Finally, a fatigue limit of 26% of the ultimate tensile strength is found, which is consistent with previous outcomes.

Effect of Diamond Burnishing on the Properties of FSW Joints of EN AW-2024 Aluminum Alloys

The article presents the results of an analysis of the surface roughness parameters, microhardness, and the stresses of the surface layer ofFSW butt joints subjected to the burnishing process with a diamond tip. This can be useful in selecting the optimal parameters of the burnishing process, ensuring the best properties of the surface layer of the FSW joint. Burnishing force and feed rate influence were analyzed according to the two-factor three-level full factorial statistical completed plan PS/DC 32. The tested material was 2024-T3 aluminum alloy sheets with a thickness of 2 mm. The results show that burnishing significantly reduced the surface roughness from Sa = 6.46 μm to Sa in the range of 0.33 μm–1.7 μm. This treatment provides high compressive residual stresses σx from −86 to −130 MPa and σy from −158 to −242 MPa. Microhardness increased from 84.19% to 174.53% compared to butt joints. Based on the obtained results, multi-criteria optimization was carried out. This optimization allows us to obtain a compromise solution ensuring compressive stresses in the surface layer (σx=−123 MPa and σy=−202 MPa) and microhardness HV=362.56 mm/mm2 with the roughness of the weld surface Sa = 0.28 µm, Sku = 3.93 and Spc = 35.88 1/mm.

Study on Pulse-Reverse Electroplating Process for the Manufacturing of a Graphene-Based Coating.

This work investigates the feasibility of increasing the electric conductivity of an AA1370 aluminium wire by using pulse-reverse electrodeposition to realize Cu-Graphene composite coating. The graphene adopted was in the form of nanoplates (GnP). To study the effects of plating parameters, a 23 factorial plan was developed and tested. During the tests, the following process parameters were varied: the current density, the frequency and the duty cycle. The ANalysis Of VAriance (ANOVA)) was adopted to evaluate their influence on the coated wires' morphology and electrical conductivity resistance. The results show that all the tested conditions allow good compactness to the coating, and the amount of graphene is well incorporated within the microstructure of the copper deposit. In addition, in the best conditions, the electrical resistivity decreases up to 3.4% than the uncoated aluminum.

Experimental Evaluation of the Factors That Influence Cylindrical Water Projection Devices against IEDs

Terrorists usually employ Improvised Explosive Devices (IEDs) to cause maximum damage with a single action, in asymmetric war scenarios. In the counter-terrorism fight, bomb disposal specialists have to combat these instruments by safeguarding their lives, avoiding fortuitous IED explosion, and preserving evidence of the device that could lead to the capture of the perpetrators. Some very effective deactivation tools that combine these features are high-speed water-explosive projection devices. To understand and quantify the impacts of the many factors that intervene in their operation and effectiveness, extensive experimental tests should be conducted. However, Operations Research techniques allow robust results to be obtained by minimizing experiments. This study focuses on the use of Design of Experiments (DoE), with a factorial experiment plan divided into two levels, to analyze the influence of the amount of explosive, the diameter of the device (that is, the mass of water to be projected), the density of the water, the distance at which the IED is located, and the resistance of the inner tube material. Results show that the mass of explosive, the diameter of the device, the interaction of the mass of explosive and the density of the water, and the interaction between the resistance of the inner tube and the diameter of the container have a strong influence on the speed of projected water.