Abstract

Microplastics pose a severe threat to marine ecosystems; however, relevant mathematical modeling and analysis are lacking. This paper formulates two stoichiometric producer-grazer models to investigate the interactive effects of microplastics, nutrients, and light on population dynamics under different settings. One model incorporates optimal microplastic uptake and foraging behavior based on nutrient availability for natural settings, while the other model does not include foraging in laboratory settings. We establish the well-posedness of the models and examine their long-term behaviors. Our results reveal that in natural environments, producers and grazers exhibit higher sensitivity to microplastics, and the system may demonstrate bistability or tristability. Moreover, the influences of microplastics, nutrients, and light intensity are highly intertwined. The presence of microplastics amplifies the constraints on grazer growth related to food quality and quantity imposed by extreme light intensities, while elevated phosphorus input enhances the system’s resistance to intense light conditions. Furthermore, higher environmental microplastic levels do not always imply elevated microplastic body burdens in organisms, as organisms are also influenced by nutrients and light. We also find that grazers are more vulnerable to microplastics, compared to producers. If producers can utilize microplastics for growth, the system displays significantly greater resilience to microplastics.

Introduction

Plastic pollution has steadily increased due to widespread plastic use, insufficient disposal practices, and limited waste management capacity over decades. Plastic wastes discharged into terrestrial and aquatic habitats are considered a serious threat to biodiversity, due to their resistance to decomposition (Gall and Thompson, 2015, Carbery et al., 2018). The small plastic particles, ranging from 0.1 to 5 mm in size, are called microplastics (EFSA Panel on Contaminants in the Food Chain (CONTAM), 2016). Microplastics are observed almost in all aquatic habitats (Eerkes-Medrano et al., 2015, Peeken et al., 2018). Chronic exposure to microplastics presents several challenges for aquatic organisms (Cui et al., 2017, Duis and Coors, 2016, Nolte et al., 2017, Zhang et al., 2017, Khoironi et al., 2019, Sjollema et al., 2016, Besseling et al., 2014).

Studies have shown that microplastics can be absorbed, concentrated, and transported into various organisms, such as algae. This process significantly hampers algal growth, chlorophyll levels, and photosynthetic activity (Cao et al., 2022, Liu et al., 2019, Chae et al., 2019, Wu et al., 2021, Jiao et al., 2022, Gray and Weinstein, 2017, Zhang et al., 2017, Sjollema et al., 2016, Yang et al., 2020, Ferguson, 2011, Wang et al., 2020, Khoironi et al., 2019, Rodrigues et al., 2019, Salman et al., 2016). This inhibition may occur due to physical factors, such as the blockage of light and airflow (Bhattacharya et al., 2010, Wang et al., 2020, Salman et al., 2016, Bhattacharya et al., 2010), or interactions between microplastics and algae, including adsorption, aggregation (Zhang et al., 2017), and the destruction of algal cell walls through surface absorption (Liu et al., 2019). However, it is worth noting that some laboratory studies suggest that certain algae species may increase in the presence of smaller-sized microplastics, possibly because microplastic particles can be utilized as substrates for the growth of algae (Yokota et al., 2017, Mao et al., 2018, Jiao et al., 2022, Canniff and Hoang, 2018).

Discussion

Microplastics can be mistakenly ingested or adhere to the surfaces of marine organisms, resulting in significant adverse effects (Zhang et al., 2017, Liu et al., 2019, Sazli et al., 2023, Gregory, 1996, Derraik, 2002, Blarer and Burkhardt-Holm, 2016, Alomar et al., 2017). This paper presents two stoichiometric models to investigate population dynamics in the presence of microplastics in both field and laboratory settings. The interactive effects of light, nutrients, and microplastics on population dynamics have been rigorously studied.

For natural ecosystems, the OMUF model reveals complex dynamics. When the microplastic concentration is relatively low, the behavior of the system is strongly influenced by the initial conditions and can exhibit bistability or tristability. Conversely, when microplastics in the environment become excessively abundant, the only outcome is the extinction of grazers. Furthermore, the tolerance to microplastics of the producer-grazer system described in OMUF model (3.5) is significantly lower, compared to that of the system defined in NM model (2.11). This discrepancy potentially arises from the fact that in the natural ecosystem, grazers have to face more challenges and pay significant feeding costs, such as food scarcity, nutrient deficiencies, predation risk, multiple toxins, and human impact, making them more susceptible to microplastics.

Extreme light condition, either too low or too high, restricts the growth of grazers. When light intensity is excessively low, producers can only survive at low densities due to weakened photosynthesis, and grazers go extinct because of insufficient food. When light intensity is excessively high, the P:C ratio in producers becomes very low, and grazers go extinct due to nutrient deficiency. However, when light intensity falls within a moderate range, coexistence of both species may occur, and the system demonstrates a greater ability to withstand microplastics.

Abstract

Membrane chromatography is mainly used for the separation and purification of proteins and biological macromolecules in the downstream processing process, also applications in sewage disposal. Membrane chromatography is recognized as an effective alternative to column chromatography because it significantly improves chromatography from affinity, hydrophobicity, and ion exchange; the development status of membrane chromatography in membrane matrix and membrane equipment is thoroughly discussed, and the applications of protein capture and intermediate purification, virus, monoclonal antibody purification, water treatment, and others are summarized. This review will provide value for the exploration and potential application of membrane chromatography.

Introduction

Traditional column chromatography has high adsorption capacity and separation accuracy for protein [1, 2]; so far, the downstream processing of biological agents has been highly dependent on the use of packed bed resin columns [3, 4]. However, traditional column chromatography generally suffers from a high-pressure drop; the intraparticle diffusion leads to the accumulation of solute molecules, which made the processing time increases, low ligand utilization, and long treatment time, which limits its productivity [5, 6]; meanwhile, column chromatography is expensive; more than 60% of the cost of the biopharmaceutical production process is concentrated in the downstream process of purification and recovery, in which the downstream purification of virus accounts for 70% of the total production cost [7, 8].

Compared with traditional column chromatography, membrane chromatography is more suitable for large proteins of separation and purification (MR > 250,000); such proteins rarely enter the pores of chromatographic particle matrix [9]. For viruses and macromolecules with obvious diffusion restrictions in conventional chromatographic media, it is particularly important [10]. Although the equilibrium binding capacity is generally low in the membrane, solutes in the membrane pores are mainly transported to the binding sites by convection, reducing the mass transfer resistance of the chromatography process (Fig. 1). Due to the advantage in mass transfer, membrane chromatography is an effective method for extracting trace proteins from large capacity feed, which can maintain their natural conformation by reducing the time in contact with adsorbents, maintaining the biological activity of the required biomolecules while removing impurities [11, 12]. Moenster et al. [13] used the SartobindQ exchange membrane adsorber method to separate and purify penicillin G amidase from cell lysate in one step, compared with previous multiple purification steps, which reduced the operating units and significantly improved the downstream processing efficiency.©

Summary and outlook

As an effective alternative to chromatographic column packing, membrane chromatography has been widely studied in the past to explore the use of virus purification; purified viruses have been used for gene treatment and production of vaccines. Ion-exchange membrane chromatography is currently used for the polishing of monoclonal antibody production processes in the biopharmaceutical industry; hydrophobic interaction chromatography membrane adsorbers are usually in flow mode and are rarely used. At present, the chromatographic process of membrane chromatography combined with column packing or monolithic column has been applied in the field of biological production processes, and has shown good application potential in the treatment of trace harmful matters such as heavy metal ions or dyes in water.

Given the relatively high raw material manufacturing cost of membrane materials, the purification capacity of membrane chromatography must reach a relatively high value, or have a high cycle of reuse to ensure a low commercial cost, to have a relatively high economic value. Predictable and high-precision theoretical models are developing to better clarify the potential mass transfer phenomena and thus improve the separation performance of membranes. Disposable membrane sorbent methods are a small market branch for chromatographic packing at present, from an adoption and evaluation perspective, in the downstream processing technology, which development is more advanced.

Abstract

1. Introduction

2. Experimental

3. Results and discussion

4. Conclusion

Conflict of Interest

Supplementary Information

References

Abstract

     This study investigates the effect of graphene oxide (GO) on the mechanical and corrosion behavior, antibacterial performance, and cell response of Mg—Zn—Mn (MZM) nanocomposite. MZM/GO nanocomposites with different amounts of GO (i.e., 0.5wt%, 1.0wt%, and 1.5wt%) were fabricated by the semi-powder metallurgy method. The influence of GO on the MZM nanocomposite was analyzed through the hardness, compressive, corrosion, antibacterial, and cytotoxicity tests. The experimental results showed that, with the increase in the amount of GO (0.5wt% and 1.5wt%), the hardness value, compressive strength, and antibacterial performance of the MZM nanocomposite increased, whereas the cell viability and osteogenesis level decreased after the addition of 1.5wt% GO. Moreover, the electrochemical examination results showed that the corrosion behavior of the MZM alloy was significantly enhanced after encapsulation in 0.5wt% GO. In summary, MZM nanocomposites reinforced with GO can be used for implant applications because of their antibacterial performance and mechanical property.

Introduction

     Currently, because magnesium (Mg) alloys have more benefits than common metallic materials, ceramics, and biodegradable polymers, their biomedical applications have been increasing. In terms of mechanical features, metals have higher mechanical strength and fracture toughness than ceramics or polymers; thus, metals are more appropriate for load-bearing usages than ceramics or polymers [1–2]. The density of human cortical bone (1.75 g/cm3 ) is similar to the density of Mg (1.738 g/cm3 ) and Mg alloys (1.75–1.85 g/cm3 ) but lower than the density of biomedical titanium alloy Ti6Al4V (4.47 g/cm3 ) [3–4]. In terms of biocompatibility, certain amounts of Mg ions in the human body are connected with many metabolic reactions and biological mechanisms [5–6]. Mg alloys are suitable orthopedic and cardiovascular implants because further surgery to remove them is not needed [7–8]. However, an important drawback of Mgbased implants is that they do not have good resistance against corrosion in physiological environments [9]. Mechanical strength could be significantly reduced by rapid and uncontrollable corrosion processes, which leads to premature failure [10]. Moreover, the health of patients who have such implants could be at risk because of the evolution of hydrogen gas and alkalinization of the environments close to the interface between implant and tissue [11]. Therefore, to achieve the secure deployment of biomedical devices, the degradation/corrosion rate of Mg alloys needs to be controlled [12]. In this context, several methods, such as alloying, powder metallurgy (PM), and surface modification strategies, have been used in an extensive number of studies that aimed to solve the problem of corrosion in Mg alloys [13–14]. Among the best methods to enhance the corrosion resistance of porous Mg are PM processes, such as mechanical alloying [15–17].

Conclusion

     In this study, using the semi-powder metallurgy method, different contents of GO were embedded in the Mg–Zn–Mn (MZM) matrix to prepare MZM/xGO nanocomposites for orthopedic applications. The corrosion performance and the 24 20 16 12 8 4 0 0 −0.5 −1.0 −1.5 −2.0 Extension / mm MZM/GO Graphene oxide Graphene oxide Graphene oxide Graphene oxide Crack Crack (a) (c) 1.5GO 0.5GO 1GO MZM (b) MZM composite MZM/0.5GO MZM/1GO MZM/1.5GO 49 59 63 64 Compression strength / N 4820 17810 19960 9620 1.12 1.31 1.44 0.72 Force / (10 3 N) Micro hardness, HV Extension / mm Material nanocomposite Fig. 10.    (a) Typical compressive curves and (b) hardness and compressive strength values of the MZM/xGO nanocomposites; (c) schematic diagram of the crack deflection toughening mechanisms of GO in the MZM/xGO nanocomposites. S. Jabbarzare et al., Effect of graphene oxide on the corrosion, mechanical and biological properties of Mg-based … 317 mechanical and biological characteristics of the MZM/xGO nanocomposites were analyzed. The microstructural assessment showed that a uniform distribution was achieved in the MZM/0.5GO and MZM/1GO nanocomposite specimens. However, agglomeration was observed in the MZM/1.5GO nanocomposite specimen. The results showed that the GO content, hardness value, and compressive strength are positively associated. In this context, the MZM/1GO nanocomposite has higher hardness value and compressive strength than the Mg-based nanocomposite without GO. The MZM/ 0.5GO nanocomposite exhibited a nearly comparable corrosion resistance to the MZM/1GO nanocomposite, even though the incorporation of more GO has an unfavorable effect on the Rct value of the MZM matrix. The MTT assay results showed that the MZM/1GO nanocomposite increased the MG63 cell viability and ALP activity, indicating the increasing level of osteogenesis. The results of the analysis of antibacterial activity showed that the MZM/1.5GO nanocomposite had a noticeable effect on antibacterial effectiveness toward bacteria, including Salmonella–Shigella and Klebsiella pneumoniae. In summary, the results indicate the possibility of utilizing the MZM/1GO nanocomposite for implant applications with effective anti-infection characteristics.

Abstract

     Circular economy approaches are commonly depicted by two cycles, where the biological cycle is associated with regeneration in the biosphere and the technical cycle with reuse, refurbishment, and recycling to maintain value and maximize material recovery. This work, instead, presents an alternative vision to the management of carbon-based materials that integrates the two cycles and enables the phasing-out of fossil carbon from the material system. The aim is to investigate the benefits and global potential of a co-recycling system, as an alternative to conventional recycling systems that separate biomass-based materials (e.g., wood, paper) from fossil-based materials (e.g., plastics). Thermochemical recycling technologies enable the conversion of carbon-based waste materials into high-quality synthetic products, promoting circularity and avoiding carbon losses such as carbon emissions and waste accumulation in landfills and nature. Here, the construction and analysis of co-recycling scenarios show how the deployment of thermochemical recycling technologies can decouple the material system from fossil resource extraction. Furthermore, energy use is reduced if pyrolysis and/or gasification are included in the portfolio of recycling technologies. In a decarbonized energy system, deployment of co-recycling can lead to near-zero carbon emissions, while in more carbon-intensive energy systems the choice of thermochemical recycling route is key to limiting carbon emissions.

Introduction

     Carbon-based fuels (mainly fossil fuels but also biomass) account for about 90% of the current global primary energy supply. Carbon is also a building block in a wide range of materials (carbon-based materials; C-materials) used in society. While fossil fuel use is the main cause of anthropogenic greenhouse gas (GHG) emissions, and a transition away from the use of such fuels is essential to limit the global temperature increase to 1.5 °C (IPCC et al., 2018), the production and use of materials such as plastics, cement and steel entail significant GHG emissions (IEA, 2018; Jambeck et al., 2015). The use of biomass-based products can effectively reduce the use of fossil fuels and GHG-intensive materials. There is also scope for substituting existing biobased products with more benign products. For example, cellulose-based textiles can replace cotton which is associated with soil and water depletion, as well as harmful impacts on human health and biodiversity due to excessive use of pesticides and fertilizers (IPCC et al., 2019c; Niinimäki et al., 2020). However, the biomass supply potential is limited by resource constraints (Gerten, 2018) and implications of expanded biomass use for mitigation and other objectives depend on many factors, including soil and climate conditions, biomass type, land management system, scale and pace of deployment, and influence on land use (Calvin et al., 2021). For instance, cropland expansion for energy crop production may cause deforestation, with consequent GHG emissions and negative impacts on biodiversity (IPCC et al., 2019b).

Conclusion

     A co-recycling scenario utilizing advanced thermochemical recycling is proposed and analyzed. The results show that such a scenario can combine natural and synthetic C-materials in the same recycling scheme and that enables to decoupling of the Carbon Material System from the extraction of fossil resources, as well as minimizing waste generation. Advanced thermochemical recycling enables the recovery of any carbon flow (CO2, natural or synthetic, losses, etc.) and the production of high-quality products. A focus on carbon recycling, instead of material recycling, can improve C-materials (wood, paper, plastics, and textiles) resource management, by increasing the resource utilization from 0.7 to 1.1 tC-material/tCRtM, i.e., producing more C-materials than resources used, as well as reducing the CMS losses by half.

Abstract

Compound separation plays a key role in producing and analyzing chemical compounds. Various methods are offered to obtain high-quality separation results. Liquid chromatography is one of the most common tools used in compound separation across length scales, from larger biomacromolecules to smaller organic compounds. Liquid chromatography also allows ease of modification, the ability to combine compatible mobile and stationary phases, the ability to conduct qualitative and quantitative analyses, and the ability to concentrate samples. Notably, the main feature of a liquid chromatography setup is the stationary phase. The stationary phase directly interacts with the samples via various basic mode of interactions based on affinity, size, and electrostatic interactions. Different interactions between compounds and the stationary phase will eventually result in compound separation. Recent years have witnessed the development of stationary phases to increase binding selectivity, tunability, and reusability. To demonstrate the use of liquid chromatography across length scales of target molecules, this review discusses the recent development of stationary phases for separating macromolecule proteins and small organic compounds, such as small chiral molecules and polycyclic aromatic hydrocarbons (PAHs).

Introduction

Separation is a critical process to isolate a particular compound, whether it is a natural product or a synthetic product. Studies of a compound’s characteristics and elucidation structure provides reliable results for pure compounds because there is no interference from other compounds. The primary source of difficulty in a separation process is the high similarity between two or more compounds, such as racemic and homologous mixtures. Liquid chromatography has proven to be an effective solution to those problems. The key to liquid chromatography separation is a sustainable retention and elution process. Stationary phases essential for separating compounds in liquid chromatography. Various liquid chromatography columns of both preparative and quantitative types have been used and continue to develop. For this reason, multiple studies and publications related to liquid chromatography can be found and accessed easily.

This review will discuss recent developments in liquid chromatography stationary phase technology for compound separation. Analytes that were once inseparable can now be separated and appropriately analyzed. The discussion focuses on the development of column material and separation interactions. This development aims to optimize and overcome the lack of existing columns. This review will discuss three types of analytes to demonstrate the use of liquid chromatography across length scales of target molecules, which are (1) larger biomolecules, particularly the proteins, (2) small chiral molecules, and (3) polycyclic aromatic hydrocarbons (PAHs).

Outlook

As liquid chromatography continues to be one of the main tools in the preparation and analysis of chemical compounds, various developments have been made to improve the binding selectivity and reusability of the columns. The surface chemistry of the stationary phases of silica, polysaccharides, and synthetic polymer matrixes has been adjusted and modified to result in better separation across length scales. The stationary phases can be chemically decorated with desired functional groups to ensure a stable and selective binding to the target molecule. For selective separation of chiral molecules, chiral stationary phases (CSPs) have been prepared using modified polystyrene, cellohydrobiolase, cyclodextrins, chiral metal–organic frameworks (MOF), and ionic liquids as chiral selectors. Hydrophobic surfaces are an essential component of liquid chromatography for PAH binding. Several hydrophobic chemical modifiers have been covalently anchored at silica surfaces to increase their affinities towards PAHs. Moreover, hydrophobic MOF and particle-based acrylics have also been developed as stationary phases to capture PAHs efficiently. In the case of protein capture and purification, affinity chromatography is commonly established through metal–protein complexation as well as ligand–protein complexation. Furthermore, by adjusting the conditions of elution, particularly the pH and ionic strength, hydrophobic charge-induction chromatography (HCIC) and mixed-mode chromatography (MMC) have also been investigated to achieve better protein purification.

Abstract

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Abstract

Worldwide, nitrogen (N) deficiency is the main yield limiting factor owing to its losses via leaching and volatilization. Urease inhibitors slow down urea hydrolysis in soil by inhibiting urease enzyme activities whereas gibberellic acid is growth regulator. That is why, we evaluated the role of urease inhibitor [N-(n-butyl)thiophosphorictriamide (NBPT)] and gibberellic acid (GA3) in improving nitrogen uptake and yield of maize under different N levels (120 and 150 kg ha−1) along with control. Both N levels alone and in combination with GA3 and NBPT significantly increased yield and yield components of maize over control. In addition, 150 kg N ha−1 + NBPT + GA3 produced highest biological, grain, and stover yields, 1000 grain weight, plant height, and N uptake exhibiting 33.15%, 56.46%, 27.56%, 19.56%, 23.24%, and 78% increase over 150 kg N ha−1, respectively. The sole use of gibberellic acid or NBPT with each level of N also improved the yield and yield components of maize compared to sole N application and control. Furthermore, application of 120 kg N ha−1 along with NBPT and GA3 performed at par to 150 kg N ha−1 + NBPT + GA3 but it was superior than sole applied 150 kg N ha−1 for all the studied traits. These results imply that application of GA3 and/or NBPT can reduce dependence on urea and improve the yield and N uptake in maize by slowing urea hydrolysis in calcareous soils and shall be practiced.

Introduction

Maize (Zea mays L.) belongs to family Poaceae and is one of the most important cultivated crop in tropical and subtropical region of the world (Nabizadeh et al. 2012; Khan et al. 2014a, b). It is the 3rd largest grain crop in Pakistan following wheat and rice (Harris et al. 2007). Maize is an exhaustive crop needs an adequate amount of essential nutrients for its abundant production, in order to fulfill the demand of the rapid increasing population of the world. Nitrogen (N) is an essential nutrient, is a basic constituent of plant growth, and improves crop production and other nutrients uptake (Zaman et al. 2008a, b; Nasim et al. 2018). Nitrogen is a mobile nutrient, it moves and is lost easily from the soil (Junejo et al. 2011) and is usually deficient in calcarious soils (Adnan et al. 2018a; Snyder et al. 2007; Shah et al. 2012). Worldwide increase in crop yield is directly proportional to synthetic fertilizer application, though the higher N fertilizer has drastically declined nitrogen use efficiency (NUE) (Tilman et al. 2002; Liu et al. 2013; Erisman et al. 2007; Turan 2021a).

Abstract

     With the emergence of battery-based electric vehicles, transportation systems gradually leave using fossil fuel-based combustion engines. Due to their reasonable performance, Lithium-ion batteries have become one of the major batteries used for electric vehicles. Although these batteries are being used in most companies, their high production cost, rare raw material, and short life cycle have raised important incentives for their recovery process. However, locating a recovery center for end-of-life Lithium-ion batteries is a multi-aspect decision making problem influenced by many criteria. For this purpose, a novel integrated decision-making model is developed based on Measuring Attractiveness by a Categorical Based Evaluation TecHnique (MACBETH) for calculating the criteria weights and Weight Aggregated Sum Product ASsessment (WASPAS) methods under the fuzzy environment with Dombi norms for evaluating the alternatives to address recovery center location selection problem considering technical as well as environmental, economic, and social aspects. To show the reliability and applicability of the developed method, a real-world case study in Istanbul is investigated. The developed method is used to evaluate six potential locations for the possible establishment of a recovery center. Results showed that Tuzla district is the most suitable location for opening a recovery center for end-of-life Lithium-ion batteries. Tuzla is in a very good position in terms of proximity to suppliers, transportation and location. To illustrate the robustness of the obtained results, extensive sensitivity analysis tests are performed.

Introduction

     Electric vehicles (EVs) are an appealing solution for the decarburization of the transportation sector (Romero-Ocaño et al., 2022, Zhang et al., 2020). It is estimated that more than 125 million EVs will be on the road worldwide by 2030 (Hua et al., 2020). Lithium-ion batteries (LiBs) have exponential growth and a key portion of industry investments (Chen et al., 2019, Cui et al., 2022). An automobile Lithium-ion battery (ALiB) is a major component of an EV (Pelletier et al., 2017, Ramoni and Zhang, 2013). ALiBs provide the required energy storage for EVs due to the superiority of high energy density, high output voltage, low self-discharge rate, and long cycling life (Tang et al., 2019, Wang et al., 2022). They are composed of a cathode, an anode, an electrolyte, and a separator (Olivetti, Ceder, Gaustad, & Fu, 2017). The useful lifetime of ALiBs is 120,000–240,000 km (Onat, Kucukvar, Tatari, & Zheng, 2016).

     Approximately 11 million ALiBs are expected to be sold worldwide by 2020 (Li et al., 2018; Alamerew & Brissaud, 2020). Due to the degradation in capacity and quality, the service life of these complex multiple material products, which belong to class 9 of dangerous goods, is 5–10 years (Li et al., 2018; Chen et al., 2019, Tang et al., 2019, Alamerew and Brissaud, 2020, Li et al., 2020). ALiB is replaced when the capacity has reached 70–80 % of its initial capacity (Alamerew and Brissaud, 2020, Hua et al., 2020, Ramoni and Zhang, 2013).

Conclusions

     The emergence of EVs has been a noticeable point for transportation systems to transform from fossil fuel-based vehicles to cleaner vehicles which require lower energy costs and also produce lower negative environmental, economic, and social impacts. The utilization of ALiBs is of great importance for EVs, but more and more valuable resources are being depleted without appropriate recovery. Therefore, countries should consider establishing recovery centers for ALiBs as soon as possible. However, locating a recovery center is a complex and multi-aspect decision-making problem. For this purpose, we developed a novel decision-making approach based on the MACBETH-D-WASPAS model under the fuzzy environment. The proposed integrated fuzzy decision-making approach empowers experts in the field of LiB management to enhance their decision-making capabilities and select the most suitable location for an EoL ALiB recovery center. Besides, the real-life case study of Istanbul is provided to show the feasibility and applicability of the developed methodology for solving the recovery center location selection problem. Results showed that Sariyer and Büyükçekmece are top first and second locations that a recovery center for an EoL ALiB recovery center. On the other hand, results pointed out that Ümraniye is the least preferred location for establishment of an EoL ALiB recovery center.

Abstract

     Two dimensional nanomaterials, such as graphene and MXene, have been widely used to fabricate high performance nanocomposite films owing to their unique structure and excellent physiochemical properties, showing enormous potential applications in many areas. However, the existing voids and wrinkling in the nanocomposite films inevitably impedes realizing the high performance of the nanocomposite films during the assembly process of graphene and MXene nanosheets. Nacre provides an inspiration for fabricating high performance graphene and MXene nanocomposite films through constructing a high alignment structure and strong interface interactions. In this review, we summarize the preparation approaches of graphene and MXene nanocomposite films and discuss the mechanical properties. Then, several effective strategies for assembling graphene and MXene nanosheets have been concluded and discussed. Meanwhile, we also summarize and discuss the applications of graphene and MXene nanocomposite films including electromagnetic interference (EMI) shielding and thermal management. Finally, outlooks and challenges are proposed to promote their progress and applications in the future.

Introduction

     Since the first discovery of graphene in 2004, graphene has gradually aroused widespread attention [1]. Due to the outstanding mechanical, electrical and thermal properties, graphene has been applied in flexible electronic devices, aerospace and thermal management fields in the past decade [2], [3], [4], [5], [6]. For instance, the single-layer graphene has a Young’s modulus of 1.0 TPa [7] and a superhigh thermal conductivity of about 5300 W/mK [8] at room temperature, demonstrating enormous practical potentiality in the above mentioned fields. Before realizing these applications, it is crucial to assemble graphene nanosheets into high performance graphene nanocomposites including one dimensional (1D) fiber, two dimensional (2D) film and three dimensional (3D) bulk. Especially, high performance graphene nanocomposite films have gained enormous attention. However, it is difficult to achieve high performance nanocomposite films due to weak interaction between adjacent graphene nanosheets. Graphene oxide (GO) is a usual precursor for obtaining graphene with plentiful surface terminating groups, which can easily interact with various materials for preparing nanocomposite films [9,10]. Meanwhile, in recent years, MXene, a novel two dimensional (2D) materials, shows promising electrical and thermal properties, which shows promising application in aerospace field [11], [12], [13], [14], [15], [16]. Indeed, compared with graphene, the intrinsic mechanical and thermal conductivity properties and stabilities of MXene is relatively poor. Furthermore, the easily oxidizable characteristics and thermal vulnerability of MXene may restrict its practical applications. However, compared with graphene, MXene has plentiful surface functional groups, which is an ideal building block for fabricating nanocomposite films without chemical modification any more.

Summary and outlook

     In the past several years, two dimensional materials such as graphene and MXene have been widely studied owing to the excellent physiochemical properties. In this review, we have focused on the preparation methods, assembling strategies and mechanical properties of graphene and MXene nanocomposite films. Moreover, we have also discussed the applications of obtained graphene and MXene nanocomposite films such as EMI shielding and thermal conductivity. Various methods such as VAF, blade coating, drop casting and LbL have been used to prepare high performance graphene and MXene nanocomposite films. However, as aforementioned, the existing voids and wrinkling are harmful for the mechanical properties of graphene and MXene nanocomposite films. Hence, several strategies for fabricating high performance graphene and MXene nanocomposite films are proposed.

Abstract

I. INTRODUCTION

II. EXPERIMENTAL DETAILS

III. RESULTS

IV. DISCUSSION

V. CONCLUSION

REFERENCES

Abstract

     Nanocomposites have been developed as the third-generation insulating materials. This article introduces the crosslinked polyethylene (XLPE) nanocomposite dielectric doped with a small amount of nano-hexagonal boron nitride ( h -BN), which exhibits excellent insulation properties under high dc voltage. The test results show that XLPE/ h -BN nanocomposites possess significant improvements in dc breakdown strength and 0.1 wt% nano h -BN doping can actually increase the dc breakdown strength by 39%. The space charge properties of the XLPE/ h -BN obtained by the pulsed electro-acoustic (PEA) measurements and the direct current integrated charge [DCIC- Q(t) ] measurements show that the positive homocharge injection under dc voltage is obviously suppressed, and the electrical conductivity under relatively high electric field decreases. The thermally stimulated current results show that the nano h -BN doping introduces only deep charge traps (above 1 eV) to the XLPE matrix. The trap energy is deeper than that of the original traps, and this is the main factor leading to the improvement of the dc insulation properties. Besides, the doping of h -BN does not introduce impurities or change the crystallinity of XLPE. This article presents the novel XLPE/ h -BN nanocomposites with excellent dc insulation properties and indicates the large potential of the nano h -BN-doped insulation materials.

Introduction

     NANOCOMPOSITES have excellent dielectric properties and have become the third-generation insulating materials [1]. Nano-doping can improve corona resistance and electrical tree characteristics as well as regulate dielectric properties of the polymer matrix. More importantly, the dc insulation properties can be enhanced to various degrees by inorganic nanoparticle doping, such as the suppression of the charge injection and transportation, as well as the increase of the breakdown strength. With the construction of high-voltage direct current (HVDC) transmission line in a large scale, the power industries have proposed stricter requirements on the dc insulation performance of insulating materials. Therefore,nanocomposite dielectrics may be more suitable for dc insulation systems in the future, and nanocomposite materials with higher insulation performance need to be continuously developed. For example, crosslinked polyethylene (XLPE)- based nanocomposites are expected to be used in the new generation of HVDC cable.

Conclusion

     The XLPE/h-BN nanocomposite with high dc breakdown strength and suppressed charge injection features were introduced in this study. It is useful to reach the conclusions as follows.

     1) XLPE/h-BN nanocomposite samples with loading content ranging from 0.1 to 3 wt% were prepared successfully. The dc Eb of the nanocomposite sample shows at most a 39% increase under 0.1 wt% loading.

     2) The effect of h-BN doping on the charge trap characteristics of XLPE is a significant increase in the density of deep traps, and this is the main cause for the improvement of dc insulation properties.

Abstract

     Concrete is a primary material in infrastructure projects and is a significant contributor to global climate emissions. However, there is a lack of readily available cement and ready-mix concrete inventory data for evaluating the environmental performance of the industries. This study describes the development of cradle-to-gate inventories for U.S. ready-mix concrete and gate-to-gate inventories for portland cement production technologies. These life-cycle inventories provide baselines for the environmental releases associated with concrete that is used for major infrastructure projects. The inventories are incorporated into the publicly available Greenhouse gases, Regulated Emissions, and Energy use in Technologies (GREET) model. The life-cycle inventories are created using facility-level environmental release data from U.S. datasets normalized to activity levels which are based on production capacity and utilization data provided by Portland Cement Association (PCA) and the U.S. Geological Survey Minerals Yearbook. Unit processes for limestone quarrying, sand and gravel quarrying, and wet-mix concrete batch plants are developed on the basis of national total point-source environmental releases and production statistics, coupled with corresponding flows associated with off-road fuel consumption and other non-point-source emissions. Midpoint impact assessment results are normalized to provide insight into their relative significance in the context of U.S.

Introduction

     Concrete is a primary structural material central to the construction projects throughout the world. It is the second most-consumed material in the world, after water (Miller et al., 2018b). Cement is the binder that holds concrete aggregates together, enabling structural performance. Global cement production of about 4.1 billion tonnes year after year since 2013 (IEA, 2021). Of this, 102 million tonnes, or 2.5%, were consumed in the U.S. Concrete can be transported, pumped, and poured to fill frames in a wide range of forms, and once cured, it is rigid and durable, making it ideal for structural elements, especially distributed transportation infrastructure. As a result, concrete is used in a wide range of construction projects. The Portland Cement Association (PCA) reports that in 2015, 30% of the cement use in the U.S. was for transportation infrastructure, 28% for residential buildings, 18% for nonresidential buildings, 13% for public utilities and water/wastewater systems, and 10% for other applications (PCA, 2016).

Conclusions

     This study provides transparent emissions data for infrastructure modeling within the GREET framework, as well as robust inventories for openLCA modeling, available for free download on the Federal LCA Commons. The four primary kiln technologies employed to produce cement are all available, in addition to the U.S. national average blend, enabling specification of blends that may be more regionally appropriate for specific LCA studies. The ready-mix concrete inventory is appropriate for commonly available truck-delivered concrete and is also adaptable for specified cement blends, including adjustments for modeling batch plants that may be set up for larger infrastructure projects. These data enable transparent assessments of concrete applications with complete inventories across a full suite of life-cycle impact categories. Researchers and decision-makers can use GREET or the data on the Federal Commons to assess the impacts associated with major concrete infrastructure projects.