Flow Of Matter Research Articles

Let there be light to interact

Light plays a crucial role in ecological dynamics, both as a consumable resource and as an environmental factor. Prokaryotic and eukaryotic photoautotrophs use light as an energy source for photosynthesis, which forms the basis of food chains and determines the flow of energy and matter in ecosystems. Light availability and quality can influence resource complementarity and species coexistence, as well as the stoichiometry of primary producers and the transfer efficiency of food webs. In addition, light serves as an important source of information for organisms, influencing their activities and interactions with the environment. Light shapes biotic interactions, including competition, predator-prey relationships, and mutualistic and antagonistic relationships between photoautotrophs and heterotrophs. Anthropogenic activities affect these photoecological processes, with largely unknown consequences. Hence, understanding the ecological role and control of light is essential for understanding the functioning of ecosystems and biogeochemical cycles.

Massive star formation in the hub–filament system of RCW 117

ABSTRACT We present a multiwavelength investigation of the hub–filament system RCW 117 (IRAS 17059-4132), which shows intricate filamentary features in the far-infrared, mapped using Herschel images. We obtain the column density and dust temperature maps for the region using the Herschel images and identify 88 cores and 12 filaments from the column density map of the region (18 arcmin × 18 arcmin). We employ the ThrUMMS 13CO (J = 1–0) data for probing the kinematics in RCW 117, and find velocity gradients (∼0.3–1 km s−1 pc−1) with hints of matter inflow along the filamentary structures. Ionized gas emission from the associated H ii region is examined using the Giant Metrewave Radio Telescope (GMRT) at 610 and 1280 MHz and is found to be of extent 5 × 3 pc2 with intensity being brightest towards the hub. We estimate the peak electron density towards the hub to be ∼750 cm−3. Thirty-four Class 0/I young stellar objects (YSOs) have been identified in the region using the Spitzer GLIMPSE colour–colour diagram, with many lying along the filamentary structures. Based on the (i) presence of filamentary structures, (ii) distribution of cores across the region, with ∼39 per cent found along the filamentary structures, (iii) massive star formation tracers in the hub, and (iv) the kinematics, we believe that global hierarchical collapse can plausibly explain the observed features in RCW 117.

FIRST DATA ON VERTICAL PARTICLE FLUXES AND ENVIRONMENTAL CONDITIONS IN THE NORTHERN PART OF THE MOHNS RIDGE, NORWEGIAN SEA

For the first time, a continuous two-year study of the particle fluxes and associated environmental parameters in the axial zone of the Arctic segment of the Mid-Atlantic Ridge at the junction of the Mohns and Knipovich Ridges (Norwegian Sea) was carried out. Sediment traps were deployed from the R/V Akademik Mstislav Keldysh in June 2019 in the northeastern part of the Mohns Ridge and realized in July 2020. It was shown that the sedimentation of sinking particles in the study area was influenced by the global transport of water masses in the northeastern direction, with Atlantic waters in the subsurface, and water masses of Arctic origin recirculating deeper in the subsurface. A weak positive temperature trend at a depth of more than 2500 m (0.02°C) is detected. The bimodal vertical distribution of fluxes and changes in the composition of sinking particles corresponded to the pattern of sediment recycling in the ocean. The annual course of fluxes in the subsurface layer was determined by the activity of silicon-concentrating and calcifying plankton, with the maximum bloom period also manifested in the deep layer. At the same time, the main significant moderator of flux deeper than 2000 m is the inflow of lithogenic matter from the benthic nepheloid layer.

Macroeconomic dynamics in a finite world based on thermodynamic potential

This paper presents a conceptual model describing the medium and long term co-evolution of natural and socio-economic subsystems of Earth. An economy is viewed as an out-of-equilibrium dissipative structure that can only be maintained with a flow of energy and matter. The distinctive approach emphasized here consists in capturing the economic impact of natural ecosystems’ depletion by human activities via a pinch of thermodynamic potentials. This viewpoint allows: (i) the full-blown integration of a limited quantity of primary resources into a non-linear macrodynamics that is stock-flow consistent both in terms of matter-energy and economic transactions; (ii) the inclusion of natural and forced recycling; (iii) the inclusion of a friction term which reflects the impossibility to produce (and recycle)goods and services without exuding energy and matter wastes, and (iv) the computation of the anthropically produced entropy as a function of metabolizing intensity and frictions. Analysis and numerical computations confirm the role played by intensity and frictions as key factors for sustainability by contrast with real gdp growth—as well as the interplay between resource scarcity, income inequality, and inflation. A more egalitarian society with moderate inflation turns out to be more sustainable than an unequal society with low inflation. Our approach is flexible enough to allow for various economic models to be embedded into our thermodynamic framework. Finally, we propose the open source EcoDyco software as a first complete realization implementing economic dynamics in a multi-resource environment.

Chronic gastrocolocutaneous fistula secondary to percutaneous endoscopic gastrostomy, a case report

Percutaneous endoscopic gastrostomy (PEG) is a widely used procedure that enables enteral nutrition in patients with deglutition anomalies. While this procedure is safe and effective, it has been reported to rarely develop unusual complications such as fistulas. Herein we present a case report of a 68-year-old male presenting a gastrocolocutaneous fistula secondary to PEG. Two years after the PEG tube placement, this patient was hospitalized due to urinary retention, the tube was changed during his stay, which onset postprandial diarrhea and the flow of fecal matter through the tube, thus raising concern for the diagnosis of a gastrocolocutaneous fistula. Keywords: Percutaneous endoscopic gastrostomy; gastrocolocutaneous fistula; gastrostomy.

Dark matter halo mass functions and density profiles from mass and energy cascade

Halo abundance and structure play a central role for modeling structure formation and evolution. Without relying on a spherical or ellipsoidal collapse model, we analytically derive the halo mass function and cuspy halo density (inner slope of −4/3) based on the mass and energy cascade theory in dark matter flow. The hierarchical halo structure formation leads to halo or particle random walk with a position-dependent waiting time tau _g. First, the inverse mass cascade from small to large scales leads to the halo random walk in mass space with tau _gpropto m_h^{-lambda }, where m_h is the halo mass and lambda is a halo geometry parameter with predicted value of 2/3. The corresponding Fokker-Planck solution for halo random walk in mass space gives rise to the halo mass function with a power-law behavior on small scale and exponential decay on large scale. This can be further improved by considering two different lambda for haloes below and above a critical mass scale m_h^*, i.e. a double-lambda halo mass function. Second, a double-gamma density profile can be derived based on the particle random walk in 3D space with a position-dependent waiting time tau _g propto Phi (r)^{-1} propto r^{-gamma }, where Phi is the gravitational potential and r is the particle distance to halo center. Theory predicts gamma =2/3 that leads to a cuspy density profile with an inner slope of −4/3, consistent with the predicted scaling laws from energy cascade. The Press-Schechter mass function and Einasto density profile are just special cases of proposed models. The small scale permanence can be identified due to the scale-independent rate of mass and energy cascade, where density profiles of different halo masses and redshifts converge to the -4/3 scaling law (rho _h propto r^{-4/3}) on small scales. Theory predicts the halo number density scales with halo mass as propto m_h^{-1.9}, while the halo mass density scales as propto m_h^{4/9}. Results were compared against the Illustris simulations. This new perspective provides a theory for nearly universal halo mass functions and density profiles.

A CULTURE OF SECURITY VERSUS DIGITAL EXCLUSION AS A FORM OF SOCIAL EXCLUSION

This article contains a brief description of the creation of an artificial environment, which is the outcome of the evolution of humankind’s natural environment. Its dynamic development is associated with anthropopressure. A sizeable share of scientists agree that we live in a new geological epoch called the Anthropocene (a term proposed in 2000 by Paul Crutzen, an atmospheric chemist), in which humans exert an increasingly noticeable impact on the entire planet and “reach out” into space. The modern human being no longer exists in their natural human environment, but dwells in the “technicized” one. In this article, the authors present the issues of social exclusion through the prism of newly created artificial human environments. They will look at the technicized human environment through the prism of security culture issues, of which exclusion, including digital exclusion, is one. The factor determining the functioning of ecosystems, and thus maintaining the phenomenon of life on Earth and then in Space, is the flow of energy and matter. Everything occurs in time; this very phenomenon is responsible for the aging of biocenosis, which in turn is subjected to exclusion processes in the habitat.

The clinical value of deep gray matter 3T MRI perfusion in patients with multiple sclerosis

Background. Multiple sclerosis (MS) is a common neurological disorder between adults. Magnetic resonance imaging (MRI) is the imaging modality of choice, new MRI techniques helped in more accurate assessment of the disease extent, activity and severity. In dynamic susceptibility contrast (DSC), the perfusion of the lesions as well as normally appearing white and gray matter of the brain have been assessed. Objective. To highlight the role of MRI perfusion of the deep gray matter in multiple sclerosis patients and its relation to their clinical disability and cognitive impairment Methods. 40 patients with MS were enrolled in this study, they were divided into two groups (group A with mild clinical disease and preserved cognitive functions, and group B with marked clinical disease and cognitive functions impairment) they were divided according to their clinical disability and cognitive impairment assessed by experienced neurologist, Additional 20 healthy controls were included. Perfusion parameters including cerebral blood volume(CBV), cerebral blood flow (CBF) and mean transit time (MTT) of the deep gray matter were compared for healthy controls and for the study groups. Results. The perfusion values of the thalamus, putamen and caudate were significantly changed in group B that shows marked decrease in CBV and CBF and increased MTT compared with group A and the controls, With respect to group (A), there was no significant difference between the patients and controls Conclusion. The decrease of perfusion of the deep gray matter in patients with MS is associated with the severity of the disease and cognitive impairment.

Soil management in the Atlantic Forest’s rural properties:

The environmental benefits arising from the interaction between matter and energy flows of permacultural systems acceleratethe recovery processes of degraded areas, which can be potentiated by the increase of plant biomass associated with thegreen manure technique, proposed in this work for the study territory: the surroundings of two Conservation Units (UC),of the Private Reserve of Natural Heritage (RPPN) type, the RPPN Águas Claras I and II. The RPPN Águas Claras I andII are located in the Macabu River basin, a microbasin of the Carukango River. The objective of this study was to analyzeareas submitted to reforestation and agroforestry system (SAF) projects, through estimates of local biomass obtained withthe aid of secondary data from the UCs’ forest inventory. As a result, it was possible to list Ficus sp and Sparattospermaleucanthum as priority native species for forest restoration. It was concluded that it is necessary to consort the two specieswith the planting of species considered green manures, in order to increase forest biomass and stimulate the improvementof soil conditions in the degraded portion of the reserve. This strategy can accelerate the regeneration process, as indicatedby secondary soil analysis data using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS),performed in the area of implementation of the SAF.

Specialized fluid estimation implementation on the FPGA

This paper studies the possibility of exploring Field Programmable Gate Array (FPGA) in the acceleration of Computational Fluid Dynamics (CFD). CFD is an industrial analysis tool to estimate the flow of matter. In the previous experience, CFD are most implemented on the conventional CPU, and may accelerate with GPUs in a high-performance computing center. This paper studies the architecture of the FPGA and compared the FPGA to CPU and the application and algorithm of CFD. We studied the previous works from different research and found that CFD occupies a huge advantage on the efficiency of the overall system. FPGA utilize less hardware resources, and usually presents a less computing time and higher throughput of data. So, FPGA is a viable and cost-effective solution for future alternative of the CFD computation with the same cost of constructing a high-performance computing center.

THE STUDY OF SOIL EROSION UNDER A SYSTEMIC CONCEPTION

This article aimed to understand how erosion processes can be analyzed from a systemic point of view. Soil erosion is considered here a naturally occurring phenomenon, which can be (and usually is) influenced by human activities, constituting one of the main environmental problems of the planet, in addition to being the main modeling agent of the terrestrial surface. The consequences of the accelerated action of erosion processes are numerous, such as: reduction of natural fertility and productive capacity of soils; silting and pollution of water bodies; impoverishment of rural communities; rural exodus; among many others. Understanding the dynamics of this phenomenon becomes fundamental because a comprehension of a spatio-temporal scope, coupled with the knowledge of the possible problems that may occur with its accelerated performance, provides support for the development of sustainable management. Given that soils are the 'foundation' of the fauna, flora, and mainly of human subsistence, it is a valuable resource. The analytical procedures of this manuscript followed the construction of a system based on a case study, exemplifying how the systemic approach can be developed in the studies of erosive processes. By analyzing soil erosion from a systemic approach, it was possible to observe how the different flows of matter and energy occurred between the variables, explain the importance of understanding erosion processes in an integrated way, and avoid fragmented and reductionist interpretations.

Environmental stressors altered the groundwater microbiome and nitrogen cycling: A focus on influencing mechanisms and pathways

Nitrogen cycling, as an important biogeochemical process in groundwater, strongly impacts the energy and matter flow of groundwater ecology. Phthalate esters (PAEs) were screened as key environmental stressors in the groundwater of Beijing, contributing to the alteration of microbial community structure and functions; thus, it could be deduced that these stressors might influence nitrogen cycling that is almost exclusively mediated by microorganisms. Identification of the influences of PAEs on groundwater nitrogen cycling and exploration of the potential influence mechanisms and pathways are vital but still challenging. This study explored the influence mechanisms and pathways of the environmental stressor PAE on nitrogen cycling in groundwater collected from a typical monitoring station in Beijing based on high-throughput sequencing and bioinformatics analysis combined with mediation analysis methods. The results suggested that among the 5 detected PAEs, dimethyl phthalate and diethyl phthalate significantly negatively impacted nitrogen cycling processes, especially nitrogen fixation and denitrification processes (p < 0.05), in groundwater. Their influences were fully or partially mediated by functional microorganisms, particularly assigned keystone genera (such as Dechloromonas, Aeromonas and Noviherbaspirillum), whose abundance was significantly inhibited by these PAEs via dysregulation of carbohydrate metabolism and activation of defense mechanisms. These findings confirmed that the influences of environmental stressors PAEs on nitrogen cycling in groundwater might be mediated by the “PAE stress–groundwater microbiome–nitrogen cycling alteration” pathway. This study may advance the understanding of the consequences of environmental stressors on groundwater ecology and support the ecological hazard assessment of groundwater stressors.

Dependency of Arctic zooplankton on pelagic food sources: New insights from fatty acid and stable isotope analyses

AbstractGlobal warming causes dramatic environmental change to Arctic ecosystems. While pelagic primary production is initiated earlier and its intensity can be increased due to earlier ice melt and extended open‐water periods, sea‐ice primary production is progressively confined on a spatio‐temporal scale, leading to unknown consequences for the ice‐associated (sympagic) food web. Understanding ecological responses to changes in the availability and composition of pelagic and sympagic food sources is crucial to determine potential changes of food‐web structure and functioning in Arctic marine communities under increasingly ice‐free conditions. Focus was placed on the importance of suspended particulate organic matter vs. sympagic organic matter for 12 zooplankton species with different feeding modes covering five taxonomic groups (copepods, krill, amphipods, chaetognaths, and appendicularians) at two ice‐covered, but environmentally different, stations in the north‐western Barents Sea in August 2019. Contributions of diatom‐ and flagellate‐associated fatty acids (FAs) to total lipid content and carbon stable isotopic compositions of these FAs were used to discriminate food sources and trace flows of organic matter in marine food webs. Combination of proportional contributions of FA markers with FA isotopic composition indicated that consumers mostly relied, directly (herbivorous species), or indirectly (omnivorous and carnivorous species), on pelagic diatoms and flagellates, independently of environmental conditions at the sampling locations, trophic position, and feeding mode. Differences were nevertheless observed between species. Contrary to other studies demonstrating a high importance of sympagic organic matter for food‐web processes, our results highlight the complexity and variability of trophic structures and dependencies in different Arctic food webs.

Microfluidics of nanoparticles using vibration-mediated regulation of aggregates evolution

Controlling the flow of particulate matter, especially nanoparticles, requires a deep understanding of particle structure and motion. In this study, we present experimental observations and intrinsic mechanisms for controlling the nanoparticle flow using vibration-mediated regulation of aggregates evolution. Our findings demonstrate that vibration could exert significant forces on the particles, causing them held apart or would touch with less force and then leads to re-breakup process of the aggregates. Furthermore, the relationship between the vibration parameter, aggregate size, the microchannel size and flow behavior has also been revealed. Notably, the outflowing aggregates have extremely small Stokes numbers due to their high porosity, and their motion is dominated by gas drag. The relationship between particles flow rate and the size of the microchannel and vibration parameters has been identified. These results have significant implications for precise control and assembly of nanoparticles.

EXERGY-BASED SUSTAINABILITY ANALYSIS OF FOOD PRODUCTION SYSTEMS

As the global population continues to grow, the sustainability of food production systems is increasingly critical, coupled with escalating environmental concerns. Traditional sustainability assessments primarily focus on resource consumption and waste generation, often overlooking the overall efficiency and quality of energy and matter flows within these systems. This comprehensive review paper explores the potential of the exergy concept as a holistic and comprehensive approach to assessing the sustainability of food production systems. Exergy analysis offers valuable insights into the thermodynamic efficiency, resource utilization, and environmental impacts of these systems. By incorporating exergy principles into sustainability assessments, researchers and policymakers can better understand the strengths, weaknesses, and opportunities for improvement in food production systems. This paper highlights key studies and applications that have utilized the exergy concept, discussing its benefits and limitations.

Factors Affecting the Efficiency of Photovoltaic System

The world's most important source of energy is the sun. The solar heating energy is the main energy source that affects the physical formations in the earth and atmosphere system. Matter and energy flows in the world are possible thanks to solar energy. Wind, sea wave, temperature difference in the ocean and biomass energies are modified forms of solar energy. Solar energy also plays a role in the realization of the water cycle in nature and creates the power of the stream. Solar energy, which is the origin of most of the natural energy sources, is directly used for purposes such as heating and electricity generation. One of the strategic goals of developed and developing countries is expanding the use of energy resources. Solar energy is almost the most widely used of alternative energy sources. In the presented article, the factors influencing the efficiency of the photovoltaic system have been determined in order to achieve effective results in the construction of the photovoltaic system. Based on the obtained indicators, it is aimed to build a photovoltaic system based on a GaAs photocell with 75% efficiency in the educational building. Aims: The goal is to use solar panels to ensure continuity of energy supply in educational buildings. Initially, it was considered to determine the parameters that will affect the efficiency of the solar panel system used.

Structural and functional changes in Artificial Reefs ecosystem stressed by trophic modelling approach: Case study in the Bay of Biscay

Artificial Reefs (ARs) are commonly cited as a tool used for increasing fishery production and reinstating ecosystem functionalities. The assessment of ARs deployment is mostly based on analysis of the evolution of fish communities. Recently, studies have focused on trophic modelling to understand the functioning of such ecosystems in a more holistic approach. Trophic models are able to address this concern by describing the interaction between species at different trophic levels and based on the quantification of energy and matter flows through ecosystems. These models allow the application of numerical methods – also called Ecological Network Analysis (ENA) – to characterize emergent properties of the ecosystem. Usually, ENA indices are proposed as indicators of ecosystem health as they are sensitive to different impacts on marine ecosystems. In the present study, the Ecopath software is used to build an ecosystem model composed of 23 compartments, from detritus and phytoplankton to mammals, to describe the situation “before” and “after” the deployment of ARs in the south of the Bay of Biscay along the Landes coast. In addition, ENA indices are calculated for two periods, “before” and “after” the deployment of artificial reefs, to compare network functioning and the overall properties of the structural trophic network. Our results show little structural change in the ecosystem, with a rearrangement of the trophic levels and a simultaneous increase in biomass and system maturity. These preliminary results evidently need to be confronted with other environmental factors such as, for instance, substrate composition, proximity to natural reefs and larval supply. Nonetheless, we consider that the maturity index could be used as a new indicator to assess the evolution of ARs with specific management objectives.

The Dynamics of Life model

AbstractThis paper attempts to formulate a generic model of living and social system at all levels with three parts. The first is the Dynamics of Life diagram, which follows flows of energy, matter and information through the system. A rule set controls how the parts co‐operate to maintain internal and external processes. As a system acts, it creates the space for a shadow system that opposes it. Unmanaged entropy is expelled or remains as a toxic element.The second is the Tree of Life that outlines the levels of functioning in a human being from biological to psychological to social. Each level manifests the flows as in the Dynamics of Life diagram.The third explores the processes of living and social systems through time and borrows heavily from Holling and Gunderson's Adaptive Cycle. The three parts present an integrated overview of the functioning of living and social systems.

On the statistical theory of self-gravitating collisionless dark matter flow

Dark matter, if it exists, accounts for five times as much as the ordinary baryonic matter. Compared to hydrodynamic turbulence, the flow of dark matter might possess the widest presence in our universe. This paper presents a statistical theory for the flow of dark matter that is compared with N-body simulations. By contrast to hydrodynamics of normal fluids, dark matter flow is self-gravitating, long-range, and collisionless with a scale-dependent flow behavior. The peculiar velocity field is of constant divergence nature on small scale and irrotational on large scale. The statistical measures, i.e., correlation, structure, dispersion, and spectrum functions, are modeled on both small and large scales, respectively. Kinematic relations between statistical measures are fully developed for incompressible, constant divergence, and irrotational flow. Incompressible and constant divergence flow share the same kinematic relations for even order correlations. The limiting correlation of velocity ρL=1/2 on the smallest scale (r = 0) is a unique feature of collisionless flow (ρL=1 for incompressible flow). On large scale, transverse velocity correlation has an exponential form T2∝e−r/r2 with a constant comoving scale r2=21.3 Mpc/h that may be related to the horizon size at matter–radiation equality. All other correlation, structure, dispersion, and spectrum functions for velocity, density, and potential fields are derived analytically from kinematic relations for irrotational flow. On small scale, longitudinal structure function follows one-fourth law of S2l∝r1/4. All other statistical measures can be obtained from kinematic relations for constant divergence flow. Vorticity is negatively correlated for scale r between 1 and 7 Mpc/h. Divergence is negatively correlated for r &amp;gt; 30 Mpc/h that leads to a negative density correlation.

Effects of connectivity on carbon and nitrogen stocks in mangrove and seagrass ecosystems

Seascape connectivity increases carbon and nitrogen exchange across coastal ecosystems through flow of particulate organic matter (POM). However, there are still critical gaps in knowledge about the drivers that mediate these processes, especially at regional seascape scales. The aim of this study was to associate three seascape-level drivers which could influence carbon and nitrogen stocks in intertidal coastal seascape: connectivity between ecosystems, ecosystem surface area, and standing vegetation biomass of ecosystems. Firstly, we compared whether connected mangrove and seagrass ecosystems contain larger carbon and nitrogen storage than isolated mangrove and seagrass ecosystems. Secondly, we compared autochthonous and allochthonous POM in mangrove patches and seagrass beds, simultaneously estimating the area and biomass relative contribution to POM of the different coastal vegetated ecosystem. Connected vs isolated mangrove and seagrass ecosystems were studied at six locations in a temperate seascape, and their carbon and nitrogen content in the standing vegetation biomass and sediments were measured. POM contributions of these and surrounding ecosystems were determined using stable isotopic tracers. In connected mangrove-seagrass seascapes, mangroves occupied 3 % of total coastal ecosystem surface area, however, their standing biomass carbon content and nitrogen per unit area was 9–12 times higher than seagrasses and twice as high as macroalgal beds (both in connected and isolated seascapes). Additionally in connected mangrove-seagrass seascapes, the largest contributors to POM were mangroves (10–50 %) and macroalgal beds (20–50 %). In isolated seagrasses, seagrass (37–77 %) and macroalgal thalli (9–43 %) contributed the most, whilst in the isolated mangrove, salt marshes were the main contributor (17–47 %). Seagrass connectivity enhances mangrove carbon sequestration per unit area, whilst internal attributes enhance seagrass carbon sequestration. Mangroves and macroalgal beds are potential critical contributors of nitrogen and carbon to other ecosystems. Considering all ecosystems as a continuing system with seascape-level connectivity will support management and improve knowledge of critical ecosystem services.