Material Consumption Research Articles

Behaviour Analysis of Beam-Type Timber and Timber-Concrete Composite Panels

This study addresses the enhancement of material efficiency and reduction in brittleness in timber-to-concrete adhesive connections for beam-type timber and timber-concrete composite panels. The research explores the potential benefits of adding longitudinal timber ribs to cross-laminated timber (CLT) beam-type panels. Three groups of flexure-tested specimens were analysed as follows: (1) timber panels (1400 mm × 400 mm) with two 100 mm thick CLT panels and two 60 mm thick CLT panels reinforced with 150 × 80 mm timber ribs; (2) eight specimens (600 mm × 100 mm × 150 mm) with CLT members (600 mm × 100 mm × 100 mm) connected to a 50 mm concrete layer using granite chips and Sikadur-31 (AB) epoxy adhesive; (3) six CLT panels (1400 mm × 400 mm × 50 mm) bonded to a 50 mm concrete layer, with two panels containing polypropylene microfibres and two panels incorporating polyethene dowels for mechanical connection. Specimens were subjected to three-point bending tests and analysed using the transformed section method, γ-method, and finite element method with ANSYS 2023R2 software. Results indicated a 53% increase in load-carrying capacity for ribbed CLT panels with no additional material consumption, a 24.8–41.1% increase for CLT panels strengthened with a concrete layer, and improved ductility and prevention of disintegration in timber-concrete composites with polypropylene microfibres.

Photoelectric conversion performance of Ga0.47In0.53As/Ge0.79Sn0.21 dual-junction thermophotovoltaic cell

Based on the photovoltaic characteristics of GeSn-based materials and the theory of stacked solar cells, Ga0.47In0.53As/Ge0.79Sn0.21 dual-junction thermophotovoltaic cell has been simulated and studied for the first time. According to existing experimental material parameters, the structure of the cell is optimized, and the photoelectric performance of the cell is profoundly studied. The findings indicate that the doping concentrations of the top/bottom cell are N a(d),t/N a(d),b = 50(7) × 1016/17(2) × 1019 cm−3, which exhibits superior photoelectric conversion performance. For reducing material consumption and achieving high performance, the thickness of the emitter (base) of the top/bottom cell can be selected as 0.8~2.0(2.0~4.0)/0~0.2(1.0~4.0) μm (T BB = 1500 K). With radiator temperatures increasing, the conversion efficiency of the cell significantly improves, and the open circuit voltage of the cell can reach 0.70~0.91 V (1000~2000 K). The research results can guide the design and fabrication of high-efficiency and economical GeSn-based multi-junction thermophotovoltaic cells, and can also provide a new research and development direction for low-cost thermophotovoltaic cells.

Advancing urban sustainability transitions: A framework for understanding urban complexity and enhancing integrative transformations

Rapid urbanization and industrialization with their negative repercussions draw attention to the need for urban sustainability. This research built on the urban systems understanding linked with resource utilization, environmental effects, people-environment interactions, and adaptive management by integrating quantitative modelling of urban metabolism with a qualitative investigation into human responses. A hybrid methodology was applied in a typical industrial city of Jinchang, China, which exemplified a model of how complex urban dynamics link to and inform sustainability transitions. The study found that Jinchang City had taken on an unsustainable trajectory underpinned by continuous growth of material consumption, whereas a potential for sustainability transitions was also observed in decoupled negative material outputs, improved material efficiency, and environment regeneration collectively. The challenges in industrial cities have been framed in terms of development model lock-in, conceptual and institutional constraints, innovation and human capital deficiencies, and governance failure. The research proposed a government-led transformation system that integrates multi-level and multi-perspective transformations and management employing discipline insights to facilitate urban sustainability transitions. This involves governance, economic and technological innovations, social transformations, and implementations, in which urban governance and public engagement are essential elements for adapting to undesirable difficulties and exploring locally appropriate strategies. This research provided a theoretical and empirical basis along with scientific and policy implications, which contributed to the developing interdisciplinary knowledge on the understanding of complex urban systems and provided insights into real-world sustainability solutions.

Assessment of material consumption planning methods in part of waste and losses at pipe industry enterprises

This article focuses on the subsystem of economic planning, specifically the standardization of material consumption in industrial production within the pipe industry, particularly in terms of calculating planned waste and loss indicators. Waste and losses are key components of the material consumption norm that currently require thorough analysis. The objective of the study is to evaluate the methodologies used in economic planning within pipe industry enterprises for standardizing waste and losses through comparison with the results of a control calculation. The main hypothesis posits that methodologies not fully adhering to the principles of the computational-analytical method of economic planning may not accurately calculate the amount of waste and losses as part of the material consumption norms. The study employs a method of comparative analysis, ensuring its reliability by developing a two-stage approach to comparing methodologies based on objective waste quantity indicators. Real data from pipe manufacturing companies is utilized to validate the author's approach, with calculations conducted using two methodologies and a control model, leading to an assessment and justification of the preferred methodology for standardization practice, highlighting its advantages. The research provides a scientific rationale for selecting the most objective standardization methodology based on two key criteria – the accuracy of economic calculations and their alignment with the production process. The conclusions and recommendations of the authors can be foundational in developing industry-specific guidelines for standardizing material consumption in the pipe industry. The adoption of a more effective methodology will result in the establishment of objective material consumption norms and enhance the quality of economic planning in pipe industry enterprises.

Investigation of static and dynamic mechanical loads on light-weight PV modules for offshore floating applications

Photovoltaic (PV) systems are significant for the transition towards renewable energy. However, their expansion is constrained by the scarcity of suitable land in proximity to electric grids. To address this issue, floating PV is a promising solution. Ensuring the robustness of floating PV installations remains a major concern, particularly regarding the mechanical load due to strong winds in open water. This study aims to assess the impact of wind on floating PV modules, by considering real wind speed values occurring at the North Sea. To achieve this objective, the influence of PV module configuration, such as inclination, is examined. Moreover, different thicknesses of PV glass are considered to find an optimum between mechanical stability and material consumption. Lastly, a resonance vibration test is performed and compared to simulations to estimate the effects of vibration on PV module stress. The findings indicate that a low inclination installation is preferable, and a glass-glass PV module with a 2.5 mm glass thickness can withstand static and dynamic mechanical loads, although long-term durability requires further investigation. Additionally, it is crucial for the standard Dynamic Mechanical Load (DML) test to include higher pressure values and an extended vibration test at the resonance frequency with the highest measured acceleration, identified after a frequency sweep.

Assessing the circularity and sustainability of circular carpets — a demonstration of circular life cycle sustainability assessment

Abstract Purpose Robust assessments are needed to identify the best circular economy (CE) approaches related to their contribution to achieving a CE by simultaneously considering the complexity of the three pillars of sustainability (environmental, economic, social). In this regard, the circular life cycle sustainability assessment (C-LCSA) framework was recently developed. This study aimed to demonstrate its applicability and capability of identifying trade-offs and interlinkages between the different dimensions using a case study of different CE approaches to carpet tiles. Methods C-LCSA integrates circularity and life cycle sustainability assessments (LCSA). Thus, this study applied the material circularity indicator (MCI) in parallel to life cycle assessment (LCA), life cycle costing (LCC), and social life cycle assessment (S-LCA). The last technique was applied as social hotspot assessment. Five CE approaches of carpet tiles produced in the US, including strategies like reducing the consumption of primary materials through recycled and bio-based feedstock or replacing carpet tiles for a longer overall service life, as well as recycling, were assessed and compared to their mainly linear counterpart. Results and discussion The study revealed that recycling carpet tiles containing recycled and bio-based materials at the end-of-life (EoL) resulted in the lowest global warming potential (8.47 kg CO2 eq.) and the highest circularity (MCI value of 0.76, with 1 indicating the maximum level of circularity) compared to the other scenarios. However, this scenario had a trade-off with a higher acidification potential (0.039 kg SO2 eq.) and higher costs (US$19.98) compared to the disposal scenario. On the other hand, the scenario using primary, non-bio-based materials in production and disposing of the carpet tiles at their EoL performed the worst in circularity (MCI value of 0.11) and implied high environmental impacts while being more cost-effective (US$10.27). Conclusions C-LCSA transparently revealed interlinkages in terms of circularity and the overall sustainability performance of different CE approaches. While no significant differences in terms of social hotspots were identified, approaches associated with a higher circularity and improved environmental performance in most impact categories tended to result in higher costs. This emphasized the need for individual and holistic assessments of the new CE approach to identify and address trade-offs. To enhance and foster C-LCSA in academia and industry, further studies applying the framework to different sectors are encouraged.

Does circularity mean environmental sustainability? Novel evidence from European countries.

The objective of this research is to evaluate the effects of green economy initiatives (GEI) on environmental sustainability (ES) through empirical means. The degree of green economy efforts is measured using six different metrics: the percentage of circular material consumption (GEI_MA), municipal trash generation per person (GEI_MW), recycling waste performance (GEI_RW), and recycling and secondary raw materials-related patents (GEI_PA). The latter particularly comprises the biowaste (GEI_RB) and e-waste (GEI_RE) recycling shares. Our analysis, which included information gathered from 19 European nations from 2012 to 2019, shows that GEI_MW significantly improves EPI and ECO. On the other hand, there is no meaningful connection between ecological sustainability and GEI_PA. EPI is strongly positively impacted by GEI_MA and EPI and ECO are positively impacted by GEI_RW. Additionally, GEI_RB has a beneficial impact on EPI, HLT, and ECO, but GEI_RE has a considerable favorable impact on both HLT and ECO. These findings highlight how crucial it is for the government to fund R&D for green economy projects in order to achieve ecological sustainability.

Investigation of Back Surface Field Layer for High Efficiency Ultrathin In2S3 based CIGS Solar Cell

AbstractA comprehensive study of a novel structure for In2S3 based CIGS solar cell has been observed. The effects of the absorber layer and temperature with various back surface field (BSF) layers (SnS/SnTe/MoTe2/GeTe) are analyzed with the SCAPS‐1D simulator. Performances of the ultrathin CIGS solar cell enhanced with the proposed structure of ZnO:Al/i‐ZnO/In2S3/CIGS/BSF/Mo and efficiency reached over 24% with 1000 nm CIGS absorber layer. The cell with SnS BSF layer has obtained 24.41% efficiency but shows less stability with temperature variation. On the other hand, the cell with MoTe2 BSF shows better stability at a higher temperature and reached an efficiency of 24.14%. Besides, the cell with SnTe BSF also suitable for ultrathin In2S3/CIGS, which results in an efficiency of 23.27%. However, the cell with GeTe BSF can give just over 18% efficiency, but it shows greater stability with temperature changes. This study highlights the potential of BSF layer in In2S3/CIGS solar cell enhancing the performance and stability of cells by reducing recombination losses. The incorporation of a 50 nm BSF layer allows further thinning of the absorber layer, reducing material consumption in the fabrication process without sacrificing overall efficiency.

Compliance with the SDGS: Eco-Efficiency Index of Thedistrict Municipality of Pichanaqui, Province Ofchanchamayo - Peru

Objective: Determine the eco-efficiency index of the District Municipality of Pichanaqui from June to December 2023. Method: The methodology of the Ministry of Environment of 2016 was used to diagnose the eco-efficiency baseline, to determine the degree of importance of the eco-efficiency indexes, the Delphi survey was applied and the methodology to estimate the level of sustainable development of territories was used for the eco-efficiency index. Results: The eco-efficiency index result was 0.52, representing an unstable state of eco-efficiency. Contribution: It will help the municipality obtain greater value with a lower consumption of resources or raw materials for the production of goods or services they produce, in addition to mitigating the negative effects on the environment that directly or indirectly affect society.

Impact of design strategy favoring powder removal on mechanical performance of bio-inspired porous architectures for laser-based powder-bed fusion additive manufacturing

Mass reduction is a concern both in mechanical engineering and living organisms to reduce energy and materials consumption. Lately, transfer of knowledge from biology to engineering has become easier thanks to additive manufacturing. Trabecular bone for example optimally adapts to the mechanical stress it undergoes. Mass reduction methods bio-inspired from trabecular architecture, proposed in the literature, are not always applicable for laser-based powder-bed fusion. In particular, bio-inspired mass reduction methods based on a material removal principle generate porosities throughout a solid initial part which can result in enclosed porosities that trap un-melted powders. Here, we propose a 3D depowderable bio-inspired mass reduction method. Powder removal was controlled in different samples through weighing and X-ray computed microtomography and the impact of the design strategy that ensures correct powder removal on mechanical performance (stiffness) was quantified. Mean performance difference is 10.35 % (between 1.82 % and 26.47 %). For stiff and light parts loaded in bending, the proposed method outperforms parts made of bulk steel alloy by leveraging an architecture bio-inspired from trabecular bone.

Optimizing compressive strength prediction using adversarial learning and hybrid regularization

The infrastructure industry consumes natural resources and produces construction waste, which has a detrimental impact on the environment. To mitigate these adverse effects and reduce raw material consumption, waste materials can be repurposed to achieve sustainability. However, recycled materials deteriorate the intrinsic properties of concrete. A suitable ratio of natural resources and recycled aggregates can produce the desired compressive strength. Compiling sufficient data in civil engineering laboratories to make reliable conclusions is time-consuming and costly. Therefore, this research proposes a novel approach for predicting compressive strengths using limited data. The generative adversarial network was employed to generate synthetic data. Hybrid training, utilizing either conventional loss or heuristic loss, prevents the model from overfitting by adaptively adjusting the regularization term. Random noise from a multivariate normal distribution is embedded heuristically into the training samples to capture intricate data variations. Sensitivity analysis indicated that the size of recycled coarse aggregate and water are the most significant features, aligning with their correlations. Interestingly, superplasticizer, density of recycled coarse aggregate, and water absorption ratio of recycled coarse aggregate contributed significantly to predictions despite their low correlations. The propounded method outperforms random forest, support vector regression, artificial neural network, and adaptive boosting by scoring a mean squared error of 7.97, a root mean squared error of 2.82, a mean absolute error of 2.13, and a coefficient of determination of 0.96. These results suggest that the proposed technique can effectively contribute to sustainable construction practices by accurately predicting compressive strengths.

Coordinate system setting for post-machining of impeller shape by wire arc DED and evaluation of processing efficiency

Wire arc additive manufacturing (WAAM) is a direct energy deposition (DED) process that uses arc welding. It is a method of stacking beads made by melting metal wires with an arc heat source generated by a short-circuit current. Compared to other metal additive manufacturing methods, this process can be used to quickly produce large and complex-shaped metal parts. However, due to the multi-bead stacking method, the surface is highly curved and the dimensional errors are large; therefore, post-processing of the surface by cutting is required. Impellers, which are widely used in various industries, have complex shapes and high material consumption during cutting; therefore, the WAAM process can improve the manufacturing efficiency. In this study, a manufacturing process for an impeller with a diameter of 160 mm was developed by using the WAAM process. A 6-bladed fan-type impeller used for high-pressure fluid delivery was similarly modeled, and the product was additively manufactured using an Inconel 625 alloy wire. Manufacturing conditions that ensure productivity and quality or the product were determined through experimentation. Considering the post-processing of the WAAM-fabricated structure, the robot and tool paths of the impeller model were designed, and the error in the process coordinate system caused by attaching and detaching the workpiece between the two processes was reduced. Through the post-processing of the WAAM-fabricated structure, the production efficiency and process reliability were verified when the conventional manufacturing method and WAAM process were applied.

Research progress on the effects of postharvest storage methods on melon quality

Background As an important global agricultural cash crop, melon has a long history of cultivation and a wide planting area. The physiological metabolism of melon after harvest is relatively strong; if not properly stored, melon is easily invaded by external pathogens during transportation, resulting in economic losses and greatly limiting its production, development and market supply. Therefore, the storage and freshness of melon are the main challenges in realizing the annual supply of melon, so postharvest storage has received increasing amounts of attention from researchers. Methods This study used academic, PubMed, and Web of Science resources to retrieve keywords related to postharvest storage and melon quality; read, refined, classified, and sorted the retrieved literature; sorted and summarized the relevant research results; and finally completed this article. Results This article reviews the mechanism and effects of physical, chemical and biological preservation techniques on the sensory quality, compound contents and respiratory physiological activities of different varieties of melon fruits. When maintaining normal metabolism and not producing physiological disorders, melon inhibits cell wall metabolism, reactive oxygen species metabolism and the ethylene biosynthesis pathway, etc., to the greatest extent during postharvest storage, thereby reducing the material consumption of fruits, delaying the ripening and senescence process, and prolonging the postharvest life and shelf life. Conclusion The literature provides a theoretical basis for postharvest preservation technology in the melon industry in the future and provides corresponding guidance for the development of the melon industry.

Quantitative Measurement of Multiple Elements in Micro‐Quantities of Crude Oil Using In Situ Analysis by Laser Ablation‐ICP‐MS

Multi‐element quantification in small amounts of material and in situ measurements at the micrometre scale are essential aspects of geological sample investigation. A direct and rapid simultaneous multi‐elemental determination of metals in crude oil samples was carried out by combining direct laser ablation of the oil inserted in silica capillaries with inductively coupled plasma‐mass spectrometry. The accuracy of LA‐ICP‐MS determination was demonstrated by analysing CONOSTAN reference material oils, certified for multiple elements, and by comparing LA‐ICP‐MS measurement results with those obtained by ICP‐OES using microwave‐assisted sample digestion. The results obtained by both methods were in agreement with certified values. The LA‐ICP‐MS method showed an adequate precision with a mean relative standard deviation of less than 10% for multi‐element determination, and was sufficiently sensitive to determine the majority of elements. LA‐ICP‐MS was also applied to the determination of elements in crude oils of different origins. LA‐ICP‐MS is a good alternative method allowing the determination of elements in organic fluids (oil and bitumen) in shorter times, involving less material consumption, smaller test portion size and with higher throughput compared with protocols using, for instance, sample digestion. It validates the possible application of metal analysis in hydrocarbon‐containing fluid inclusions for metallogenic purposes.

Invited Article: The oxidation kinetics and mechanisms observed during ultra-high temperature oxidation of (HfZrTiTaNb)C and (HfZrTiTaNb)B2

Ultra-high temperature ceramics (UHTCs), most notably transition metal carbides and borides, exhibit melting temperatures exceeding 3000 °C, making them appropriate candidates to withstand the extreme temperatures (∼2000 °C) expected to occur at the leading edges of hypersonic vehicles. However, their propensity to react rapidly with oxygen limits their sustained application. The high entropy paradigm enables the exploration of novel UHTC compositions that may improve on the oxidation resistance of conventional refractory mono-carbides and -diborides. The oxidation kinetics of candidate high entropy group IV + V (HfZrTiTaNb)C and (HfZrTiTaNb)B2 materials were evaluated at 1500–1800 °C using Joule heating in one atmosphere 0.1%–1% oxygen/argon gas mixtures for times up to 15 min. Possible mechanisms based on the resulting complex time, temperature, and oxygen partial pressure dependencies are discussed. The carbides formed porous and intergranular oxides. Oxidation resistance was improved upon a continuous external scale formation. The diborides formed dense external scales and exhibited better oxidation resistance compared to the carbides. This improvement was attributed to the formation of liquid boria. Both compositions showed an unexpected reduction in material consumption at 1800 °C for all times tested, compared to results at lower temperatures. An in-depth analysis of the composition and morphology of the oxide scale and sub-surface regions for specimens tested at 1800 °C revealed that the formation of denser group IV-rich (Hf, Zr, Ti) oxides mitigated the formation of the otherwise detrimental liquid-forming group V (Ta, Nb) oxides, leading to the improved oxidation resistance.

Bonobo geophagy at Wamba.

Geophagy, the deliberate consumption of earth materials, is widely observed in animals. While anecdotal evidence exists of bonobos (Pan paniscus) consuming soil from Cubitermes termite mounds, the functions of their geophagic behavior remains unexplored. This study aims to examine a preliminary hypothesis that termite mound geophagy of free-ranging bonobos at Wamba are helpful for iron supplementation. Here, we tested the following three predictions: (1) the soil of Cubitermes termite mounds at Wamba would have high iron content, (2) bonobos would engage in termite mound geophagy regularly across all seasons, and (3) termite mound soil would be more often consumed by (a) females than males, (b) pregnant than non-pregnant females, and (c) adolescents than adults. As predicted, soil samples collected from the pointy protrusions on the caps of the mushroom-shaped mounds, the part typically consumed by bonobos, had a much higher iron content than other food items for them. In addition, geophagic behavior was noted on 48 out of 116 days (41.3%) with full-day focal animal sampling, and was observed throughout the entire study duration without any bias in frequency toward a certain period. However, contrary to our prediction, there was no significant variation in the frequency of geophagic behavior by sex nor by pregnancy status, although it occurred more frequently among adolescents than adults. Our findings partially support the Iron Supplementation Hypothesis, suggesting that Cubitermes termite mound soils could offer a readily accessible source of iron for bonobos. However, we cannot draw definitive conclusions on the function of their geophagic behavior from our findings without in vitro studies examining whether the ingested iron is bioavailable and whether the soil does not have properties inhibiting iron absorption. Nonetheless, this study is a first step to explore the health implications of geophagy in bonobos, extending our knowledge of this behavior in primates.

Development of universal working bodies for cultivators in inter-row processing of cotton

Abstract The development of multifunctional universal working bodies that can perform various functions with quick and uncomplicated adjustment, low energy and material consumption, and ensure high-quality processing of row spacing throughout the entire growing season of plants is in high demand. The project documents were developed for mastering the production of a cultivator with a universal working body and were introduced into the design process at BMKB-Agromash JSC. As a result, a universal working body was developed and installed on the beam of the KXU-4B cultivator, featuring quick and easy adjustment and low metal consumption. The use of a cotton cultivator equipped with universal working bodies in inter-row processing of cotton is expected to reduce labor costs by 16.0%, exploitation costs by 15.56%, and metal consumption of the aggregate by 1.23 times, as well as fuel consumption per hectare of cultivated field by 11.26%. To achieve this, a universal working body was designed that performs all technological operations typically performed by multiple working bodies mounted on existing cultivators without compromising quality. The universal working body is equipped with a wide right and left blade, allowing for the cultivation of the middle of the cotton row, slopes, and weed cutting. The result is a constructive scheme of a universal working body, where working parts are concentrated in one column, enabling the performance of technological operations during different vegetative seasons.

High‐performance supercapacitors using nanostructured polyaniline‐based carbon: Effect of electrolytes

AbstractDeveloping high‐performance materials for electrochemical energy storage devices such as batteries, and supercapacitors is a significant topic in material chemistry‐based research. The high consumption and limited availability of numerous materials used in energy devices lead to the development of alternative, effective, and cost‐effective materials exhibiting superior electrochemical chemical performance. A porous activated carbon, derived from polyaniline (PANI) synthesized through chemical oxidative polymerization, can be considered a viable solution in this context. In this study, the electrochemical window of the nitrogen‐doped porous activated carbon was enhanced through a combined synthesis process involving the carbonization and activation of PANI nanotubes with KOH. Moreover, alternations in surface area and porosity were evaluated using BET analysis for the samples having PANI to KOH ratios 1:0.5, 1:1, and 1:2. The results revealed a significant improvement in surface area and pore volume, increasing from 18 to 3535 m2/g from pure PANI to chemically treated samples. Among those materials, the PANI to KOH ratio of 1:1 exhibited the highest surface area of 3535 m2/g and the highest pore volume of 0.7131 cm3/g. Subsequently, the electrochemical performance of all materials was evaluated using a three‐electrode cell system and a symmetrical coin‐cell device. Electrodes fabricated with PANI to KOH ratio of 1:1 by weight showed better electrochemical performance in an aqueous electrolyte (6 M KOH) in both systems. This material exhibited the highest capacitance of 378 F/g (at 0.5 A/g) in the three‐electrode system and 143 F/g (at 0.5 A/g) in the SCCD. The SCCD achieved a maximum energy density of 23 Wh/kg with a power density of 544 W/kg. Additionally, these supercapacitors provided a good Coulombic efficiency of about 99% with capacitance retention of 97% at 7 A/g current density after 10 000 charge–discharge cycles. Further, this study expanded by investigating variations of electrochemical performance across various electrolytes, including aqueous, organic, and ionic liquids in coin‐cell supercapacitors. The findings reveal promising results, suggesting potential commercial applications for this facile approach to synthesize nitrogen‐doped activated carbon, especially for supercapacitors with aqueous electrolytes.

Analysis of carbon shell of billets with high casting speed

Abstract The increasing casting speed of billets is beneficial for improving single-machine production efficiency, reducing refractory material consumption, and achieving energy conservation and consumption reduction. However, as the casting speed increases, the probability of steel leakage also increases. An analysis of the thickness of the billet shell under high casting speed allows us to analyze the reasons for steel leakage and propose targeted solutions. This article analyzes the steel leakage billet shell of grade 40 steel and concludes that the thickness of the billet shell is between 8-20 mm at the upper of the mold, and only 5-10 mm at the lower of the mold. At the beginning of its formation, the shell of the cast billet is not uniform, with a maximum difference of up to 8 mm. As the casting progresses, the shell of the billet actually becomes thinner. At a distance of 100-200 mm from the mold, the maximum air gap between the billet shell and the copper tube reaches about 5.5 mm. The air gap reduces the uniformity of heat transfer, resulting in an uneven billet shell. After the liquid steel is injected into the shell, it will cause remelting of the solidification shell, resulting in thinning of the casting shell and causing steel leakage at the outlet of the mold.

Tracking and risk assessment of microplastics in a wastewater treatment plant

AbstractToday, microplastics have become one of the most important environmental concerns. Wastewater treatment plants are a major source of microplastics in the environment. The aim of this study is to track and assess the risk of microplastics in a wastewater treatment plant. Samples were taken from different units of sewage treatment plants in the spring and winter. Microplastics were separated using sieves and density‐based methods. Analysis revealed a higher abundance of microplastics in spring. The highest amount of microplastic removal was in the disinfection and secondary sedimentation units in the winter season. Fragments are the most common shape. Poly Ethylene Terephthalate (PET) polymers were most prevalent. Black was the most common colour. Poly Ethylene (PE), PET and poly Amide (PA) polymers posed the highest risk, according to calculations. One of the most important ways to prevent microplastics from entering water sources is to reduce the consumption of plastic materials, recycle plastic waste and remove microplastics from the wastewater treatment process.