Approaches for sediment associated pollutant monitoring in the River Danube

1994 ◽  
Vol 30 (5) ◽  
pp. 157-165 ◽  
Author(s):  
Peter Literathy ◽  
Ferenc Laszlo ◽  
Bela Csanyi
Keyword(s):  
Hot Spots ◽  
Petroleum Hydrocarbons ◽  
Dynamic Equilibrium ◽  
Pollution Monitoring ◽  
Physical Processes ◽  
Representative Sampling ◽  
Biological Stress ◽  
Chemical Measurements ◽  
Downstream Reach ◽  
Selection Of

Inorganic and organic pollutants (nutrients and toxic pollutants) are liable to accumulate in suspended and bottom sediments. The major transport of these pollutants takes place in the suspended load. Sedimentation and resuspension are in dynamic equilibrium along the river influenced mainly by physical processes. International and national surveys on the Danube sediment concluded that the Danube reach between Vienna and Budapest is one of the most polluted ones in addition to the Irongate reservoir and the downstream reach. The main polluting compounds are petroleum hydrocarbons, including PAHs, and heavy metals. Reservoirs are the major traps of sediment-bound pollutants where pollutant “time-bombs” may be developed. Pollutant monitoring of the bottom sediment requires careful selection of the representative sampling sites where the sediment contains at least 10 percent clay and silt which is enriched in pollutants. Mobilization of the sediment-bound pollutants will result in biological uptake by the benthic organisms. The macrozoobenthons monitoring provides valuable evidence for chronic biological stress associated with contaminated sites. Benthic biodiversity decreased along the studied Danube reach downstream of recognized hot spots such as major cities (Vienna, Bratislava, Budapest) and polluted tributaries (the Vah river, etc.). Harmonization between chemical measurements and biological observations in the sediment could eventually lead to an effective Danube pollution monitoring system.

The main principles and results of pollution monitoring of sediments in the river basin

2020 ◽  
pp. 14-20
Author(s):  
B. Korzhenevsky ◽  
Gleb Tolkachev ◽  
Nikolay Kolomiycev
Keyword(s):  
Heavy Metals ◽  
River Basin ◽  
Water Exchange ◽  
Pollution Monitoring ◽  
Small Rivers ◽  
Volga River ◽  
Natural Landscape ◽  
Volga River Basin ◽  
Ivankovo Reservoir ◽  
Selection Of

The problems of modern geological ecology associated with the study of pollution of sediments of water bodies by heavy metals are considered. The Volga River basin is quite heterogeneous, both in geomorphological and hydrological terms, and in thechnogenical development and usage. A fourrank taxonomy is presented for the selection of sites for monitoring, based on a combination of natural, landscape, climatic and thechnogenical factors. To the largest – the highest taxon – sites of the Ist category – bowls of reservoirs with the slopes and the urban zones, industrial and agricultural structures located within them are carried. Within these areas are allocated to smaller taxa, areas category IInd are the industrial and urban zones, areas category IIIrd are the small rivers without significant contamination and areas category IVth to conduct special observations. The examples of special observations in the study of the annual migration of heavy metals in the system «bottom sediments – water column» on the Ivankovo reservoir are highlighted. The investigations were carried out under the conditions of the standard flow rate for this reservoir and in the conditions of slow water exchange.

scholarly journals Distortion Effects in Equal Area Unit Maps

2021 ◽  
Author(s):  
Jochen Schiewe
Keyword(s):  
Hot Spots ◽  
Extreme Values ◽  
Generation Process ◽  
Equal Area ◽  
Topological Relationships ◽  
Area Unit ◽  
Task Oriented ◽  
Local Topology ◽  
Selection Of ◽  
Local Extreme

AbstractMaps that correctly represent the geographic size and shape of regions, taking into account scaling and generalization, have the disadvantage that small regions can easily be overlooked or not seen at all. Hence, for some map use tasks where small regions are of importance, alternative map types are needed. One option is the so-called equal area unit maps (EAUMs), where every enumeration unit has the same area size, possibly also the same basic shape such as squares or hexagons. The geometrical distortion of EAUMs, however, leads to a more difficult search for regions as well as a falsification of topological relationships and spatial patterns. To describe these distortions, a set of analytical measures is proposed. But it turns out that the expressiveness of these measures is rather limited. To better understand and to model the influence of distortions, two user studies were conducted. The study on the search in EAUMs (also with the aim of reconstruct the search strategies of the users) revealed how important it is to consider the local topology (e.g. corner or border positions of regions) during the generation process. With regard to pattern identification, it could be shown that EAUMs significantly increase the detection rate of local extreme values. On the other hand, global lateral gradients or geostatistical hot spots often get blurred or even lost. As a consequence, a task-oriented selection of map types and further developments are recommended.

Simulation on the Physical Process of Neural Electromagnetic Signal Generation Based on a Simple but Functional Bionic Na+ Channel

2021 ◽  
Author(s):  
Fan Wang ◽  
Jingjing Xu ◽  
Yanbin Ge ◽  
Shengyong Xu ◽  
Yanjun Fu ◽  
...  
Keyword(s):  
Dynamic Equilibrium ◽  
Electromagnetic Signal ◽  
Na Channel ◽  
Physical Processes ◽  
Flux Transport ◽  
Ionic Flux ◽  
Concentration Difference ◽  
Voltage Gated ◽  
Electromagnetic Signals ◽  
The Impact

Abstract The physical processes occurring at open Na+ channels in neural fibers are essential for understanding the nature of neural signals and the mechanism by which the signals are generated and transmitted along nerves. However, there is less generally accepted description of these physical processes. We studied changes in the transmembrane ionic flux and the resulting two types of electromagnetic signals by simulating the Na+ transport across a bionic nanochannel model simplified from voltage-gated Na+ channels. Results show that the Na+ flux can reach a steady state in approximately 10 ns owing to the dynamic equilibrium of Na+ ions concentration difference between the both sides of membrane. After characterizing the spectrum and transmission of these two electromagnetic signals, the low-frequency transmembrane electric field is regarded as the physical quantity transmitting in waveguide-like lipid dielectric layer and triggering the neighboring voltage-gated channels. Factors influencing the Na+ flux transport are also studied. The impact of the Na+ concentration gradient is found higher than that of the initial transmembrane potential on the Na+ transport rate, and introducing the surface-negative charge in the upper third channel could increase the transmembrane Na+ current. This work can be further studied by improving the simulation model; however, the current work helps to better understand the electrical functions of voltage-gated ion channels in neural systems.

scholarly journals Research progress of analysis method of slope stability combined with hot spots

2020 ◽  
Vol 198 ◽  
pp. 02008
Author(s):  
XIE Qiao ◽  
ZHANG Jia-sheng ◽  
Wang Xuan
Keyword(s):  
Slope Stability ◽  
Hot Spots ◽  
Development Trend ◽  
Research Progress ◽  
Analysis Methods ◽  
Scope Of Application ◽  
The Times ◽  
The Development Trend ◽  
Selection Of

The analysis methods and theories of slope stability are constantly improving and developing, and more methods in line with the development characteristics of the times have been put forward by scholars at home and abroad. Combined with the latest research hot spots in the direction of analysis methods of slope stability in the world, the analysis methods of slope stability are systematically classified and summarized; The principles, characteristics, scope of application of various methods are summarized; The development trend of slope stability analysis is comprehensively analyzed from various aspects. It provides the follow-up scholars with the research of new methods. It can provide reference for the selection of evaluation methods of practical slope engineering stability.

scholarly journals Genomic Diversity ofLactobacillus salivarius

2010 ◽  
Vol 77 (3) ◽  
pp. 954-965 ◽  
Author(s):  
Emma J. Raftis ◽  
Elisa Salvetti ◽  
Sandra Torriani ◽  
Giovanna E. Felis ◽  
Paul W. O'Toole
Keyword(s):  
Hot Spots ◽  
Gene Clusters ◽  
Genomic Variation ◽  
Genomic Diversity ◽  
Comparative Genomic ◽  
Phenotypic Traits ◽  
Lactobacillus Salivarius ◽  
Genome Content ◽  
High Level ◽  
Selection Of

ABSTRACTStrains ofLactobacillus salivariusare increasingly employed as probiotic agents for humans or animals. Despite the diversity of environmental sources from which they have been isolated, the genomic diversity ofL. salivariushas been poorly characterized, and the implications of this diversity for strain selection have not been examined. To tackle this, we applied comparative genomic hybridization (CGH) and multilocus sequence typing (MLST) to 33 strains derived from humans, animals, or food. The CGH, based on total genome content, including small plasmids, identified 18 major regions of genomic variation, or hot spots for variation. Three major divisions were thus identified, with only a subset of the human isolates constituting an ecologically discernible group. Omission of the small plasmids from the CGH or analysis by MLST provided broadly concordant fine divisions and separated human-derived and animal-derived strains more clearly. The two gene clusters for exopolysaccharide (EPS) biosynthesis corresponded to regions of significant genomic diversity. The CGH-based groupings of these regions did not correlate with levels of production of bound or released EPS. Furthermore, EPS production was significantly modulated by available carbohydrate. In addition to proving difficult to predict from the gene content, EPS production levels correlated inversely with production of biofilms, a trait considered desirable in probiotic commensals.L. salivariusdisplays a high level of genomic diversity, and while selection ofL. salivariusstrains for probiotic use can be informed by CGH or MLST, it also requires pragmatic experimental validation of desired phenotypic traits.

scholarly journals OBSERVATION OF ΔφΔη SCALED CORRELATION SIGNALS WHICH INCREASE WITH CENTRALITY OF AuAu COLLISIONS AT $\sqrt{^SNN} = 200\ {\rm GeV}$

2007 ◽  
Vol 16 (07n08) ◽  
pp. 2149-2153 ◽  
Author(s):  
◽  
R. S. LONGACRE
Keyword(s):  
Charged Particle ◽  
Transverse Momentum ◽  
Hot Spots ◽  
Poster Session ◽  
Pair Correlation ◽  
Wave Model ◽  
Minimum Bias ◽  
Momentum Range ◽  
Selection Of ◽  
Star Detector

We show the preliminary charged-particle pair correlation analyses presented in a poster session at the 2006 International Quark Matter Conference in Shanghai China. The correlation analysis space of Δφ (azimuth) and Δη (pseudo-rapidity) are considered as a function of centrality for minimum bias Au + Au collisions in the mid-transverse momentum range in the STAR detector. The analyses involve unlike-sign charge pairs and like-sign charge pairs, which are transformed into charge-dependent (CD) signals and charge-independent (CI) signals. We use a multiplicity scale to compare the different centralities. We find the signals increase with increasing centrality. A model featuring dense gluonic hot spots as first proposed by van Hove predicts that the observables under investigation would have sensitivity to such a substructure should it occur. A blast wave model including multiple hot spots motivates the selection of transverse momenta in the range 0.8 GeV /c < pt < 4.0 GeV /c.

Research on Establishing Monitoring Index System of Pollution Source in Puhe Basin

2014 ◽  
Vol 641-642 ◽  
pp. 1159-1162
Author(s):  
Di Wang ◽  
Kun You ◽  
Jin Xiang Fu ◽  
Si Peng Cao
Keyword(s):  
Monitoring System ◽  
Comprehensive Evaluation ◽  
Thermal Power ◽  
Water Environment ◽  
Ammonia Nitrogen ◽  
Pollution Source ◽  
Pollution Monitoring ◽  
Volatile Phenol ◽  
Construct System ◽  
Selection Of

Scientific and reasonable monitoring indexes are the key to establish monitoring system. Based on the single index, it is essential to launch the optimization and selection of indicators. Take thermal power as the research object in demonstration area and adopt comprehensive evaluation and three parameters evaluation methods to select index, successfully construct system of monitoring indicators which include in COD, suspended solids, sulfur, oil, volatile phenol and ammonia nitrogen. It will provide theoretical basis and technical support to build intelligent water environment safety and pollution monitoring system.

scholarly journals Marine Litter Windrows: A Strategic Target to Understand and Manage the Ocean Plastic Pollution

2021 ◽  
Vol 8 ◽  
Author(s):  
Andrés Cózar ◽  
Stefano Aliani ◽  
Oihane C. Basurko ◽  
Manuel Arias ◽  
Atsuhiko Isobe ◽  
...  
Keyword(s):  
Hot Spots ◽  
Applied Research ◽  
Pollution Monitoring ◽  
Plastic Pollution ◽  
Marine Litter ◽  
Large Item ◽  
Marine Life ◽  
Aerial Surveys ◽  
Management Plans ◽  
Methodological Approaches

Windrow is a long-established term for the aggregations of seafoam, seaweeds, plankton and natural debris that appear on the ocean surface. Here, we define a “litter windrow” as any aggregation of floating litter at the submesoscale domain (&lt;10 km horizontally), regardless of the force inducing the surface convergence, be it wind or other forces such as tides or density-driven currents. The marine litter windrows observed to date usually form stripes from tens up to thousands of meters long, with litter densities often exceeding 10 small items (&lt;2 cm) per m2 or 1 large item (&gt;2 cm) per 10 m2. Litter windrows are generally overlooked in research due to their dispersion, small size and ephemeral nature. However, applied research on windrows offers unique possibilities to advance on the knowledge and management of marine litter pollution. Litter windrows are hot spots of interaction with marine life. In addition, since the formation of dense litter windrows requires especially high loads of floating litter in the environment, their detection from space-borne sensors, aerial surveys or other platforms might be used to flag areas and periods of severe pollution. Monitoring and assessing of management plans, identification of pollution sources, or impact prevention are identified as some of the most promising fields of application for the marine litter windrows. In the present Perspective, we develop a conceptual framework and point out the main obstacles, opportunities and methodological approaches to address the study of litter windrows.

Extended Observations and New Insights of Dynamically Triggered Tremor in Parkfield

2021 ◽  
Author(s):  
Allie Hutchison ◽  
Piero Poli
Keyword(s):  
San Andreas Fault ◽  
Peak Ground Velocity ◽  
Dynamic Strain ◽  
Frequency Content ◽  
Physical Processes ◽  
Dynamic Triggering ◽  
Physical Conditions ◽  
San Andreas ◽  
Triggered Tremor ◽  
Selection Of

&lt;p&gt;We create an extended catalog of dynamically triggered tremor in the Parkfield region of the San Andreas Fault for teleseismic and regional earthquakes from 2001-2020 with a magnitude threshold of M &gt;7. After selection of clear dynamic triggering episodes, each tremor event is precisely located using a multi station approach. Using this new catalog of triggered tremor, we quantitatively evaluate the conditions under which tremor is triggered. In particular, we study the effect of frequency dependent peak dynamic strain, peak ground velocity, and the incident azimuth of triggering waves. We further try to assess if the triggering potential in the San Andreas Fault evolves as function of time. Finally, we search for differences and similarities (e.g. frequency content, location) between triggered and regular tremor. Our observations provide new insights about the physical conditions necessary for triggering tremor, and in general, on the physical processes generating non-volcanic tremors.&lt;/p&gt;

scholarly journals Safeguarding the microbial water quality from source to tap

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jorien Favere ◽  
Raquel G. Barbosa ◽  
Tom Sleutels ◽  
Willy Verstraete ◽  
Bart De Gusseme ◽  
...  
Keyword(s):  
Drinking Water ◽  
Dynamic Equilibrium ◽  
Anthropogenic Activities ◽  
Microbiological Quality ◽  
High Quality ◽  
Microbial Water Quality ◽  
Available Nutrients ◽  
Quality Water ◽  
Selection Of

AbstractAnthropogenic activities and climate change can deteriorate the freshwater quality and stress its availability. This stress can, in turn, have an impact on the biostability of drinking water. Up to now, the microbiological quality of drinking water has been maintained through the selection of high-quality water sources allied to the use of disinfectants and the removal of organic carbon. But as freshwater becomes richer in other nutrients, strategies used so far may not suffice to keep a steady and high-quality supply of drinking water in the future. This article readdresses the discussion on drinking water biostability. We need to reframe the concept as a dynamic equilibrium that considers the available nutrients and energy sources (potential for growth) relative to the abundance and composition of the bacterial community (potential to consume the available resources).

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