Strategic use of thermo-chemical processes for plastic waste valorization

Plastic is one of the most widely used materials in industries including packaging, building, and construction due to its lightweight, low cost, durability, and versatility. However, the mass production of plastics has exacerbated plastic pollution. Globally, plastic waste is predominantly incinerated, landfilled, or released into the environment;only 5-6% is recycled in the United States. Although conventional management protocols such as incineration and landfilling are evidently effective for plastic waste disposal, they are associated with significant environmental and societal challenges. In addition, most recycled plastic is downcycled, and thus does not provide sufficient incentive to use recycled materials instead of virgin materials. This review discusses thermo-chemical upcycling processes such as (catalytic) pyrolysis and heterogeneous catalysis. Furthermore, we present the recent progress in the thermo-chemical upgrading of single-type plastic waste, heterogeneous plastic mixtures, and post-consumer plastic waste obtained from different locations and, finally, suggest future research directions.

Optimizing process parameters for the production of intercalated melt-blown nonwoven materials for face masks based on machine learning algorithms

Currently a new type of coronavirus is raging around the world, and many countries have relaxed the control of the epidemic. Wearing a mask has become the best self-protection measure for people to travel. Intercalated melt-blown nonwoven materials are in short supply as filter layers for daily-worn masks. This paper studies the relationship between the process parameters and structural variables of intercalated melt-blown nonwoven materials, and creatively uses machine learning-related algorithms to solve its nonlinear relationship. The optimized back propagation neural network model is the most suitable in this field, and the goodness of fit can reach more than 99.99%. Based on various limitations of actual industrial production, this model is used to traverse the process parameters, and the intercalated melt-blown nonwoven material is obtained. The best process parameters, in which the receiving distance is 27 cm, and the hot air velocity is 890 r/min, in this case, the thickness and porosity of the material produced are very low, while the compression resilience is very high, considering the filtration efficiency of the mask and comfort. © The Author(s) 2023.

A Review on the Recycling Technologies of Fibre-Reinforced Plastic (FRP) Materials Used in Industrial Fields

Fibre-reinforced plastic (FRP) materials are attracting growing interest because of their high specific mechanical properties. These characteristics, in addition to a high level of tailorability and design of freedom, make them attractive for marine, aerospace, automotive, sports and energy applications. However, the large use of this class of material dramatically increases the amount of waste that derives from end-of-life products and offcuts generated during the manufacturing processes. In this context, especially when thermosetting matrices are considered, the need to deeply study the recycling process of FRPs is an open topic both in academic and industrial research. This review aims to present the current state of the art of the most affirmed recycling technologies used for polymeric composites commonly used in industrial applications, such as carbon and glass FRPs. Each recycling method (i.e., chemical, thermal and mechanical) was analysed in terms of technological solutions and process parameters required for matrix dissolution and fibre recovery, showing their advantages, drawbacks, applications and properties of the recycled composites. Therefore, the aim of this review is to offer an extensive overview of the recycling process of polymeric composite materials, which is useful to academic and industrial researchers that work on this topic.

A Review on Current Nanofiber Technologies: Electrospinning, Centrifugal Spinning, and Electro‐Centrifugal Spinning

Nanofiber‐based products are widely used in the fields of public health, air/water filtration, energy storage, etc. The demand for nonwoven products is rapidly increasing especially after COVID‐19 pandemic. Electrospinning is the most popular technology to produce nanofiber‐based products from various kinds of materials in bench and commercial scales. While centrifugal spinning and electro‐centrifugal spinning are considered to be the other two well‐known technologies to fabricate nanofibers. However, their developments are restricted mainly due to the unnormalized spinning devices and spinning principles. High solution concentration and high production efficiency are the two main strengths of centrifugal spinning, but beaded fibers can be formed easily due to air perturbation or device vibration. Electro‐centrifugal spinning is formed by introducing a high voltage electrostatic field into the centrifugal spinning system, which suppresses the formation of beaded fibers and results in producing elegant nanofibers. It is believed that electrospinning can be replaced by electro‐centrifugal spinning in some specific application areas. This article gives an overview on the existing devices and the crucial processing parameters of these nanofiber technologies, also constructive suggestions are proposed to facilitate the development of centrifugal and electro‐centrifugal spinning.

Optimization of gasification process parameters for COVID-19 medical masks using response surface methodology

Due to the COVID-19 pandemic, large amounts of medical wastes have been produced and their disposal has resulted in environmental and human health problems. This medical waste may include face masks, gloves, face shields, goggles, coverall suits, and other related wastes, such as hand sanitizer and disinfectant containers. To address this issue, the effect was investigated of gasification process parameters (type of COVID-19 medical mask based on the polypropylene ratio, pressure, steam ratio, and temperature) on hydrogen syngas and cold gas efficiency. The gasification model was developed using process modeling based on the Aspen Plus software. Response surface methodology with a 3k statistical factorial design was used to optimize the process aiming for the highest hydrogen yield and cold gas efficiency. Analysis of variance showed that both the steam ratio and temperature were significant parameters regarding the hydrogen yield and cold gas efficiency. Proposed models were constructed with very high accuracy based on their coefficient of determination (R2) values being greater than 0.97. The optimum conditions were: 65 % polypropylene in the mixture, a pressure of 1 bar, a steam ratio of 0.38, and a temperature of 900 °C, producing a maximum hydrogen yield of 40.61 % and cold gas efficiency of 81.43 %. These results supported the efficacy of the primary design for steam gasification using a mixture of plastic wastes as feedstock. The hydrogen could be utilized in chemical applications, whereas the efficiency could be used as a basis for further development of the process. © 2022 THE AUTHORS

2nd International Conference on Recent Advances in Mechanical Engineering Research and Development, ICRAMERD 2021

The proceedings contain 79 papers presendted at a virtual meeting. The special focus in this conference is on Recent Advances in Mechanical Engineering Research and Development. The topics include: Firmware of Indigenous and Custom-Built Flexible Robots for Indoor Assistance;Automation of AM Via IoT Towards Implementation of e-logistics in Supply Chain for Industry 4.0;Evaluation and Optimization of Process Parameter for Surface Roughness of 3D-Printed PETG Specimens Using Taguchi Method at Constant Printing Temperature;Evaluation of Preventive Activities of COVID-19 Using Multi-criteria Decision Making Method;mechanical Characterization of Concrete with Rice Husk-Based Biochar as Sustainable Cementitious Admixture;Ranking of Barriers for SSCM Implementation in Indian Textile Industries;Framework to Monitor Vehicular GHG Footprint;solution to Real-Time Problem in Shifter Knob Assembly at Automobile Manufacturing Industry;performance of Chemical Route-Synthesized SnO2 Nanoparticles;a Numerical Study to Choose the Best Model for a Bladeless Wind Turbine;Effect of Tissue Properties on the Efficacy of MA on Lungs;effect of Process Parameters and Coolant Application on Cutting Performance of Centrifugal Cast Single Point Cutting Tools;Study and Analysis of Thermal Barrier Application of Lanthanum Oxide Coated SS-304 Steel;recovery of Iron Values from Blast Furnace Gas Cleaning Process Sludge by Medium Intensity Magnetic Separation Method;fatigue Analysis of Rectangular Plate with a Circular Cut-Out;protection of Vital Facilities from the Threat of External Explosion Using D3o Material;investigation on Coefficient of Heat Transfer Through Impact of Engine Vibration;electrical Modulus and Conductivity Study of Styrene-Butadiene Rubber/Barium Hexaferrite Flexible Polymer Dielectrics;preface.

A case study on dynamic capabilities developed by a product start-up to grow at the time of pandemic: JITCAR

Business operations became challenging when the COVID-19 pandemic struck, and governments applied significant lockdown measures to stop the spread. Start-ups and small-medium businesses started facing hardships due to the changes in the business environment and the resulting constricted cash flow. This case describes challenges faced by a high-tech product start-up company and the way they tackled these hardships. The company had adopted an agile programming methodology for product development which faced a major challenge because of the sudden introduction of “work from remote” (WFR). WFR had disrupted collaboration between clients, sales teams, and development teams. The success of agile methodology was dissipating as teams could not do on-premise huddles. The company witnessed an overrun in the sprint schedule, increase of budgeted cost, and sliding customer satisfaction. Senior management could not manage process parameters properly, and therefore predictability of the processes waned. The start-up owners, through the application of the “dynamic capabilities framework,” focused on reconfiguring the agile working processes and improving the remote working capability of employees. This case shows the start-up’s agile development process transformation journey following the dynamic capabilities framework to overcome the challenges posed by the pandemic. The teaching case focuses on imparting knowledge on agile development and dynamic capabilities to Information Systems students.

Obtaining the effective gripper dimensions for a kiwifruit harvesting robot using kinematic calibration procedures

Purpose>A harvesting robot is developed as part of kiwifruit industry automation in New Zealand. This kiwifruit harvester is currently not economically viable, as it drops and damages too many kiwifruit in the harvesting task due to the positional inaccuracy of the gripper. This is due to the difficulties in measuring the exact effective dimensions of the gripper from the manipulator. The purpose of this study is to obtain the effective gripper dimensions using kinematic calibration procedures.Design/methodology/approach>A setup of a constraint plate with a dial gauge is proposed to acquire the calibration data. The constraint plate is positioned above the robot. The data is obtained by using a dial gauge and a permanent marker. The effective dimensions of the gripper are used as error parameters in the calibration process. Calibration is exercised by minimizing the difference between target positions and measured positions iteratively.Findings>The robot with the obtained effective dimensions is tested in the field. It is found that the fruit drops due to positional inaccuracy of the gripper are greatly reduced after calibration.Practical implications>The kiwifruit industry in New Zealand is growing rapidly and announced plans in 2017 to double global sales by 2025. This growth will put extra pressure on the labour supply for harvesting. Furthermore, the Covid pandemic and resulting border restrictions have dramatically reduced seasonal imported labour availability. A robotic system is a potential solution to address the labour shortages for harvesting kiwifruit.Originality/value>For kiwifruit harvesting, the picking envelope is well above the robot;the experimental data points obtained by placing a constraint plate above the robot are at similar positions to the target positions of kiwifruit. Using this set of data points for calibration yields a good effect of obtaining the effective dimension of the gripper, which reduces the positional inaccuracy as shown in the field test results.

Generalized Type-2 Fuzzy Parameter Adaptation in the Marine Predator Algorithm for Fuzzy Controller Parameterization in Mobile Robots

This article is oriented to the application of generalized type-2 fuzzy systems in the dynamic adjustment of the parameters of a recent metaheuristic based on nature that follows the rules of the best feeding strategies of predators and prey in ecosystems. This metaheuristic is called fuzzy marine predator algorithm (FMPA) and is presented as an improved variant of the original marine predator algorithm (MPA). The FMPA balances the degree of exploration and exploitation through its iterations according to the advancement of the predator. In the state of the art, it has been shown that type-2 fuzzy increases metaheuristic performance when adapting parameters, although there is also an increase in the execution time. The FMPA with generalized type-2 and interval type-2 parameter adaptations was applied to a group of benchmark functions introduced in the competition on evolutionary computation (CEC2017);the results show that generalized FMPA provides better solutions. A second case for FMPA is also presented, which is the optimal fuzzy control design, in the search for the optimal membership function parameters. A symmetrical distribution of these functions is assumed for reducing complexity in the search process for optimal parameters. Simulations were carried out considering different degrees of noise when analyzing the performance when simulating each of the used fuzzy methods.

Problems and technical solutions of capture fisheries in Eastern Indonesian waters

Problems concerning capture fisheries in Eastern Indonesian Waters cover the existing of fishes at sea, continuity of catching activities, the use of fishing gears, safety aspects, market, price and recent situation of pandemic Covid-19. This conditions have the impact on decreasing of economy aspect of local fishermen. The purpose of this research is to develop facility of capture fisheries and other related technical aspects to overcome the existing problems and to keep the continuity of fishing activities. The research started by initial field survey by the authors. In addition, related problems from other references are used as input design parameters. Design process end-up with the blue prints and the design specifications of fishing boats and fishing gears. The research was continued with construction of boats prototype, training for the fishermen and sea trials. The results of research were prototypes and design specifications of several types of fishing boats. Fishing boats with hull configurations (monohull, catamaran and trimaran) and fishing gears specification were fixed due to boat operational aspects. In addition, the results of study concerning safety aspect and ship operation in period of Pandemic Covid-19 are presented in this paper. Recommendations of results of this study are presented for future development of fishing boats for local fishermen.

Effects of the 3DP process parameters on mechanical properties of polylactic acid part used for medical purposes

PurposeThis paper aims to investigate effect of infill density, fabricated built orientation and dose of gamma radiation to mechanical tensile and compressive properties of polylactic acid (PLA) part fabricated by fused deposit modelling (FDM) technique for medical applications.Design/methodology/approachPLA specimens for tensile and compressive tests were fabricated using FDM machine. The specimens geometry and test method were referred to ASTM D638 and ASTM D695, respectively. Three orientations under consideration were flat, edge and upright, whereas the infill density ranged from 0 to 100%. The gamma radiation dose used to expose to specimens was 25 kGy. The collected data included stress and strain, which was used to find mechanical properties, i.e. yield strength, ultimate tensile strength (UTS), fracture strength, elongation at yield, elongation at UTS and elongation at break. The t-test was used to access the difference in mechanical properties.FindingsCompressive mechanical properties is greater than tensile mechanical properties. Increasing number of layer parallel to loading direction and infill density, it enhances the material property. Upright presents the lowest mechanical property in tensile test, but greatest in compressive test. Upright orientation should not be used for part subjecting to tensile load. FDM is more proper for part subjecting to compressive load. FDM part requires undergoing gamma ray for sterilisation, the infill density no less than 70 and 60% should be selected for part subjecting to tensile and compressive load, respectively.Originality/valueThis study investigated all mechanical properties in both tension and compression as well as exposure to gamma radiation. The results can be applied in selection of FDM parameters for medical device manufacturing.

A QbD Approach for Evaluating the Effect of Selective Laser Sintering Parameters on Printability and Properties of Solid Oral Forms.

The aim of this work was to investigate the effect of process parameters on the printability of a formulation containing copovidone and paracetamol, and on the properties of solid oral forms 3D-printed through selective laser sintering. Firstly, the influence of the heating temperature was evaluated individually, and it was revealed that this parameter was critical for printability, as a sufficiently high temperature (100 °C) is necessary to avoid curling. Secondly, the effects of laser power, scan speed, and layer thickness were determined using a Box-Behnken design. The measured responses, printing yield, height, weight, hardness, disintegration time, and percentage of drug release at 10 min showed the following ranges of values: 55.6-100%, 2.92-3.96 mm, 98.2-187.2 mg, 9.2-83.4 N, 9.7-997.7 s, and 25.8-99.9%, respectively. Analysis of variance (ANOVA) proved that the generated quadratic models and the effect of the three-process parameters were significant (p < 0.05). Yield improved at high laser power, low scan speed, and increased layer thickness. Height was proportional to laser power, and inversely proportional to scan speed and layer thickness. Variations in the other responses were related to the porosity of the SOFs, which were dependent on the value of energy density. Low laser power, fast scan speed, and high layer thickness values favored a lower energy density, resulting in low weight and hardness, rapid disintegration, and a high percentage of drug release at 10 min. Finally, an optimization was performed, and an additional experiment validated the model. In conclusion, by applying a Quality by Design approach, this study demonstrates that process parameters are critical for printability, but also offer a way to personalize the properties of the SOFs.

Manufacturing Considerations for the Development of Lipid Nanoparticles Using Microfluidics.

In the recent of years, the use of lipid nanoparticles (LNPs) for RNA delivery has gained considerable attention, with a large number in the clinical pipeline as vaccine candidates or to treat a wide range of diseases. Microfluidics offers considerable advantages for their manufacture due to its scalability, reproducibility and fast preparation. Thus, in this study, we have evaluated operating and formulation parameters to be considered when developing LNPs. Among them, the flow rate ratio (FRR) and the total flow rate (TFR) have been shown to significantly influence the physicochemical characteristics of the produced particles. In particular, increasing the TFR or increasing the FRR decreased the particle size. The amino lipid choice (cationic-DOTAP and DDAB; ionisable-MC3), buffer choice (citrate buffer pH 6 or TRIS pH 7.4) and type of nucleic acid payload (PolyA, ssDNA or mRNA) have also been shown to have an impact on the characteristics of these LNPs. LNPs were shown to have a high (>90%) loading in all cases and were below 100 nm with a low polydispersity index (≤0.25). The results within this paper could be used as a guide for the development and scalable manufacture of LNP systems using microfluidics.