Microplastics in Landfills: A Comprehensive Review on Occurrence, Characteristics and Pathways to the Aquatic Environment

Microplastics, a multi-dimensional environmental stressor group, capable of transboundary migration, are a threat to the global ecosystem. Transboundary migration of microplastics across all environmental matrices is known to originate from a multitude of sources and acts in conjugation with each other. This inter-dependence of sources calls for a detailed scientific analysis of all the sources that are in play. Waste management facilities have already been established as a significant contributor of microplastics to the aquatic and terrestrial environment. A systematic overview of the scientific literature reveals that the existing body of scientific knowledge is mainly focused on wastewater treatment facilities as a source/pathway of microplastics in the environment. Recently the focus shifted towards solid waste management facilities through landfills. Poor plastic waste management practices made discarded plastics the most dominant component of solid wastes. This review elucidates the occurrence and distribution of microplastics, characteristics of microplastics, including size, shapes, colors, and polymer types, in leachate and refuse of landfills. Furthermore, we discussed the transport mechanisms and pathways used by microplastic present in landfills to migrate to subsurface or groundwater and adjacent aquatic bodies. Last, based on the findings, we summarized the gaps in existing studies and suggested future perspectives to be focused on the future. The abundance of microplastics is attributed to the volume of plastic waste in landfills, management of leachate originating from landfills, application of leachate, and age of landfills. Microplastics abundance and characteristics vary in leachate and refuse. Smaller microplastics are predominant in leachate while larger microplastics are predominant in refuse. Landfills are capable of generating secondary microplastics from fragmentation and degradation. Further studies on microplastics in landfills are necessa

Enzymatic and Microwave Pretreatments and Supercritical CO2 Extraction for Improving Extraction Efficiency and Quality of Origanum Vulgare L. spp. hirtum Extracts

The goal of the study was to establish a procedure for improving the efficiency of supercritical carbon dioxide (scCO2) extraction of Origanum vulgare L. spp. hirtum (Greek oregano) and enhancing the quality of obtained extracts. Microwave and enzymatic pretreatments of the plant material were applied prior to the scCO2 extraction. It was determined that the microwave pretreatment with irradiation power 360 W during 2 min accelerated the extraction of lipophilic compounds and provided a twofold higher extraction yield compared to the control. Moreover, this pretreatment also led to an increase in oxygenated monoterpenes content and the most dominant component carvacrol, as well as the extracts’ antioxidant activity. The enzymatic pretreatment caused a significant increase in the extraction yield and the attainment of the extract with the most potent antioxidant properties. Coupling the pretreatments with scCO2 extraction improves the process of obtaining high value lipophilic products of oregano in terms of utilization of the plant material, acceleration of the extraction with the possibility to adjust its selectivity and quality of extracts, and enhancement of biological activity.

New In-Flame Flammability Testing Method Applied to Monitor Seasonal Changes in Live Fuel

Improving the accuracy of fire behavior prediction requires better understanding of live fuel, the dominant component of tree crowns, which dictates the consumption and energy release of the crown fire flame-front. Live fuel flammability is not well represented by existing evaluation methods. High-flammability live fuel, e.g., in conifers, may maintain or increase the energy release of the advancing crown fire flame-front, while low-flammability live fuel, e.g., in boreal deciduous stands, may reduce or eventually suppress flame-front energy release. To better characterize these fuel–flame-front interactions, we propose a method for quantifying flammability as the fuel’s net effect on (contribution to) the frontal flame energy release, in which the frontal flame is simulated using a methane diffusion flame. The fuel’s energy release contribution to the methane flame was measured using oxygen consumption calorimetry as the difference in energy release between the methane flame interacting with live fuel and the methane flame alone. In-flame testing resulted in fuel ignition and consumption comparable to those in wildfires. The energy release contribution of live fuel was significantly lower than its energy content measured using standard methods, suggesting better sensitivity of the proposed metric to water content- and oxygen deficiency-associated energy release reductions within the combustion zone.

An overview of tritium retention in dust particles from the JET-ILW divertor

Tritium (T) retention characteristics in dust collected from the divertor in JET with ITER-like wall (JET-ILW) after the third campaign in 2015-2016 (ILW-3) have been examined in individual dust particles by combining radiography (tritium imaging plate technique) and electron probe micro-analysis. The results are summarized and compared with the data obtained after the first campaign in 2011-2012 (ILW-1). The dominant component in ILW-1 dust was carbon (C) originating from tungsten-coated carbon fibre composite (CFC) tiles in JET-ILW divertor and/or legacy of C dust after the JET operation with carbon wall. Around 85 % of the total tritium retention in ILW-1 dust was attributede to the C dust. The retention in tungsten (W) and beryllium (Be) dominated particles was 100 times smaller than the highest T retention in carbon-based particles. After ILW-3 the main component contributing to the T retention was W. The number of small W particles with T increased, in comparison to ILW-1, most probably by the exfoliation and fragmentation of W coatings on CFC tiles though T retention in individual W particles was smaller than in C particles. The detection of only very few Be-dominated dust particles found after ILW-1 and ILW-3 could imply stable Be deposits on the divertor tiles.

The Root Mycobiota of Betula aetnensis Raf., an Endemic Tree Species Colonizing the Lavas of Mt. Etna (Italy)

Betula aetnensis is an endemic tree of high conservation value, which thrives on the nutrient-poor volcanic soils of Mount Etna. Since plant–microbe interactions could play a crucial role in plant growth, resource uptake, and resistance to abiotic stresses, we aimed to characterize the root and rhizosphere microbial communities. Individuals from natural habitat (NAT) and forest nursery (NURS) were surveyed through microscopy observations and molecular tools: bacterial and fungal automated ribosomal intergenic spacer analysis (ARISA), fungal denaturing gradient gel electrophoresis (DGGE). B. aetnensis was found to be simultaneously colonized by arbuscular (AM), ectomycorrhizal (ECM), ericoid (ERM) fungi, and dark septate endophytes (DSE). A high diversity of the bacterial community was observed whilst the root fungal assemblage of NAT plants was richer than that of NURS. Root and rhizosphere fungal communities from NAT plants were characterized by Illumina MiSeq sequencing. Most of the identified sequences were affiliated to Helotiales, Pezizales, and Malasseziales. Ascomycota and Basidiomycota dominated roots and rhizosphere but differed in community structure and composition. ECM in the roots mainly belonged to Tylospora and Leccinum, while Rhizopogon was abundant in the rhizosphere. The Helotiales, including ERM (mostly Oidiodendron) and DSE (mostly Phialocephala), appeared the dominant component of the fungal community. B. aetnensis harbors an extraordinarily wide array of root-associated soil microorganisms, which are likely to be involved in the adaptation and resistance mechanisms to the extreme environmental conditions in volcano Etna. We argue that nursery-produced seedlings could lack the necessary microbiota for growth and development in natural conditions.

Fundamental investigation using active plasma control to reduce blade–vortex interaction noise

Blade vortex interaction noise is a problematic and dominant component of rotor noise. Plasma actuators strategically placed at the tip of the rotor blades can reduce the strength of the tip vortices. This reduction has the potential to significantly reduce blade vortex interaction noise. A combined experimental, numerical, and theoretical program shows supporting evidence that low power plasma actuators can effectively lower coherence of the blade tip vortex and reduce blade vortex interaction noise over-pressure by up to 80%. For a nominal small five-bladed unmanned aerial vehicle, we predict an approximate 8.88 maximum ΔdB reduction for a 150 m/s tip speed. Experimental, computational, and acoustic modeling support these predictions. This study represents a fundamental investigation in the fixed-frame, which provides evidence for higher level research and testing in a rotating framework.

Cosmological scenario in κ(R,T) gravity

In this paper, we investigate the cosmic acceleration and the behavior of dark energy (DE) in the structure of the recently proposed [Formula: see text] gravity theory [G. R. P. Teruel, [Formula: see text] gravity, Eur. Phys. J. C 78 (2018) 660]. In this study, we obtained some fascinating cosmological features that are coherent with observational evidences and the touchstone [Formula: see text]CDM model. To find the deterministic solution, we consider a periodic deceleration parameter [Formula: see text], where [Formula: see text] [M. Shen and L. Zhao, Oscillating quintom model with time periodic varying deceleration parameter, Chin. Phys. Lett. 31 (2014) 010401], which predicts the decelerating and accelerating phases of the universe. The Equation of State (EoS) parameter also supports the idea of DE, which is the dominant component and it is responsible for the universe’s accelerated expansion. Here, we also construct cosmographic parameters, like, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and studied their evolution in spatially flat [Formula: see text] gravity. We find that these observations are sufficient in comparison with the universe’s physical and kinematic properties and also consistent with ongoing (OHD[Formula: see text][Formula: see text][Formula: see text]JLA) observation. Next, we apply the geometric diagnostics, the state-finder ([Formula: see text]) in [Formula: see text] gravity to discriminate from the [Formula: see text]CDM model. We found that our model lies in quintessence and the Chaplygin Gas region. Finally, the model approaches [Formula: see text]CDM at the present epoch of the universe.

"What's in a Lunchbox?": A Story About New Zealand Ideals of Health, Social Class and Ethnicity Told Through Sandwiches and the Children Who Eat Them

<p>Through an ethnographic investigation of school lunchboxes, this thesis explores if and how difference and Otherness is understood by children. In three urban New Zealand primary schools I examine how children construct, affirm and/or challenge social inequalities and issues of inclusion by looking at the contents, concepts, narratives and activities related to the consumption and sharing of their lunch food. Literature dedicated to social class (Bourdieu, 1984) and identity (Rikoon, 1982; Stern, 1977) has documented the way in which food is creatively used to reaffirm unity and belonging within minority groups (Camp, 1979; Abrahams & Kalcik, 1978). In contrast to this approach, I review the role of food as a ‘safe space’ (Mercon, 2008: 5) where diversity may be allowed to symbolically exist for the purpose of affirming the unity of the nation state, while ultimately muffling deeper social differences. The thesis thus questions the assumption that food, identity and social cohesion are conceptually linked. My overall argument centres on the “humble” sandwich, which I claim is constructed as the core, dominant component of the lunchbox, mutually constituting nutritional, social class and ethnic tropes, practices and values. I assess the discourses, behaviours and symbolism that historically situates the sandwich as iconicaly or emblematically “Kiwi”, contending that via the creation of a dychotomized system (i.e. healthy, good, skinny, well-behaved, energetic, Kiwi versus junk-food, bad, fat, naughty, sick, Other) children are enculturated into the logics of work and socialized to be compliant with structures of inequality. Thus, while the sandwich appears equally accessible to all, the differences in its production can result in practices of class based distinction (Bourdieu, 1984) and ethnic exclusion (Hage, 2003). However, my analysis also reveals that children are not mere subjects of structure, but that they reproduce, challenge, mediate, and re-shape these discourses and behaviours.</p>

"What's in a Lunchbox?": A Story About New Zealand Ideals of Health, Social Class and Ethnicity Told Through Sandwiches and the Children Who Eat Them

<p>Through an ethnographic investigation of school lunchboxes, this thesis explores if and how difference and Otherness is understood by children. In three urban New Zealand primary schools I examine how children construct, affirm and/or challenge social inequalities and issues of inclusion by looking at the contents, concepts, narratives and activities related to the consumption and sharing of their lunch food. Literature dedicated to social class (Bourdieu, 1984) and identity (Rikoon, 1982; Stern, 1977) has documented the way in which food is creatively used to reaffirm unity and belonging within minority groups (Camp, 1979; Abrahams & Kalcik, 1978). In contrast to this approach, I review the role of food as a ‘safe space’ (Mercon, 2008: 5) where diversity may be allowed to symbolically exist for the purpose of affirming the unity of the nation state, while ultimately muffling deeper social differences. The thesis thus questions the assumption that food, identity and social cohesion are conceptually linked. My overall argument centres on the “humble” sandwich, which I claim is constructed as the core, dominant component of the lunchbox, mutually constituting nutritional, social class and ethnic tropes, practices and values. I assess the discourses, behaviours and symbolism that historically situates the sandwich as iconicaly or emblematically “Kiwi”, contending that via the creation of a dychotomized system (i.e. healthy, good, skinny, well-behaved, energetic, Kiwi versus junk-food, bad, fat, naughty, sick, Other) children are enculturated into the logics of work and socialized to be compliant with structures of inequality. Thus, while the sandwich appears equally accessible to all, the differences in its production can result in practices of class based distinction (Bourdieu, 1984) and ethnic exclusion (Hage, 2003). However, my analysis also reveals that children are not mere subjects of structure, but that they reproduce, challenge, mediate, and re-shape these discourses and behaviours.</p>

Adaptive strategies of the microbial community in meromictic soda Lake Doroninskoye (Transbaikalia, Russia)

The adaptive strategies of biogeochemical systems are considered as a criterion for natural fluctuations of the territory using the example of the microbial community in meromictic soda Lake Doroninskoye (Transbaikalia, Russia). The features of the phylogenetic and functional diversity of the microbial community of the lake have been investigated. In the off-season, a change in the dominant component of the community in the chemocline of the lake was established. During the ice period, the lake is dominated by metabolically flexible, anoxygenic, photoheterotrophic non-sulfuric purple bacteria Rhodospirillaceae and Rhodobacteraceae (class Alphaproteobacteria), which can switch from anoxic photosynthesis to aerobic chemotrophic metabolism. During the open water period, facultative aerobic bacteria of the families Enterobacteriaceae (class Gammaproteobacteria) and Alcaligenaceae (class Betaproteobacteria) predominate, which switch to denitrification in the absence of oxygen.