Modelling of migration of leached radionuclides by groundwater

1986 ◽  
Vol 319 (1545) ◽  
pp. 97-108
Keyword(s):  
Mathematical Modelling ◽  
Water Flow ◽  
Chemical Processes ◽  
Levels Of Detail ◽  
Mathematical Expressions ◽  
Waste Repository ◽  
Physical And Chemical ◽  
Future Work ◽  
The Way

Radionuclides may be carried by groundwater from an underground waste repository to places accessible to man. The central role of mathematical modelling is to predict how their concentration varies in time at positions around the repository. This requires consideration of the physical and chemical processes at work and representation of the most important by mathematical expressions. As this can be done on several levels of detail both for water flow and radionuclide behaviour the resulting overall models can differ greatly in completeness and complexity. We discuss briefly some examples of such models, the data they require, the way these are gathered and how they have been used in practice. It is necessary to examine the validity of proposed models and we describe some approaches to this. We indicate the strengths and weaknesses of some commonly adopted models and outline current and future work aimed at improving our understanding.

Fate of Chemicals

2017 ◽  
Author(s):  
Morton Lippmann ◽  
Richard B. Schlesinger
Keyword(s):  
Biogeochemical Cycles ◽  
Chemical Processes ◽  
Physical And Chemical ◽  
Biotic Environment

This chapter discusses how, following their release into the environment, chemicals may be converted into different forms and/or transferred within and between the atmosphere, hydrosphere, lithosphere, and biosphere. It reviews the physical and chemical processes by which specific pollutants and classes of pollutions may be altered and ultimately dispersed within each of the components of the environment. The role of biogeochemical cycles in the movement of pollutants from the abiotic to the biotic environment is reviewed. Ultimate sinks for pollutants are discussed as are pollutant residues in the environment.

Understanding the role of post-CCVD synthetic impurities, functional groups and functionalization-based oxidation debris on the behaviour of carbon nanotubes as a catalyst support in cyclohexene hydrogenation over Pd nanoparticles

RSC Advances ◽  
2016 ◽  
Vol 6 (91) ◽  
pp. 88538-88545 ◽  
Author(s):  
R. Puskas ◽  
A. Sápi ◽  
Á. Kukovecz ◽  
Z. Kónya
Keyword(s):  
Catalyst Support ◽  
Chemical Properties ◽  
Pd Nanoparticles ◽  
Chemical Processes ◽  
Physical And Chemical Properties ◽  
Surface Chemical ◽  
Physical And Chemical ◽  
Striking Effect ◽  
And Chemical Properties

Tuning of the surface modification has a striking effect on the physical and chemical properties of CNTs in surface chemical processes.

Reply to Professor Katznelson

1989 ◽  
Vol 3 ◽  
pp. 51-55
Author(s):  
Terrence J. Mcdonald
Keyword(s):  
Recent Work ◽  
Political Development ◽  
Urban Politics ◽  
American Political Development ◽  
Political Machine ◽  
Future Work ◽  
The Way

Professor Katznelson's essay deserves a lengthy reply, but space limitations require me to keep my response brief. I strongly disagree with the way that he has characterized the thrust of my essay, the point of my other work, and the implications of recent work by other urban historians. But rather than hash over these misinterpretations, I will focus instead on the issue between us that I think has the most relevance for future work on the role of urban politics in American political development: the utility of a focus on the urban political machine.

scholarly journals Impact of Biocorrosion on the Durability of Etics and Empirical Findings About the Periodocity of Maintenance

2013 ◽  
Vol 21 (2) ◽  
pp. 21-28
Author(s):  
Naďa Antošová
Keyword(s):  
Building Materials ◽  
Composite System ◽  
Chemical Processes ◽  
Biological Factors ◽  
Wide Range ◽  
Living Organisms ◽  
Physical And Chemical ◽  
The Impact ◽  
Complete Collapse

Abstract Generally, the role of living organisms (especially bacteria, cyanophytes, algae and fungi) in the physical and chemical processes of the biocorrosion of an external thermal insulation composite system (ETICS) is underestimated. These organisms are the ones that are responsible for a wide range of changes in or "diseases" of building materials and constructions, including damage to a building´s appearance or the destruction and complete collapse of the characteristics and requirements of materials and the ETICS construction. The following article concerns the impact of biological factors on the durability of ETICS. It shows the importance of and necessity to maintain it, and the method and periodicity of the maintenance.

scholarly journals Digitalisation and Sustainable Work: obstacles and pathways

2021 ◽  
Vol 6 (2) ◽  
pp. 187-197
Author(s):  
Jan Jan Johansson ◽  
Lena Abrahamsson
Keyword(s):  
New Technology ◽  
Paid Work ◽  
Human Beings ◽  
The Future ◽  
Future Work ◽  
The Way

Work is a central part of our lives in many aspects. Half of our awake time is for most of us performed as paid work. At work, we create the values we need to live the life we desire. At work, we are socialized and shaped into the human beings we are. We are all concerned about how our work will be in the future; will we be able to handle the new technology or will we be replaced by a robot? Do we see the new technology as The wolf is coming or God's gift to mankind? This is an existential question and the future work is shaped here and now. This means that we need to get a picture of what is happening so we can act, but we also need a vision of where we want to go. Our mission as a researcher is to find the pathways to the Sustainable work, but in order to to find the way, we sometimes have to take on the role of the wolf and ask the uncomfortable questions.

Porosity/Diffusivity And Alkali-Silica Reaction

1988 ◽  
Vol 137 ◽  
Author(s):  
Micheline Moranville-Resocurd
Keyword(s):  
Chemical Processes ◽  
Alkali Silica Reaction ◽  
Physical Processes ◽  
Alkali Ions ◽  
Water Imbibition ◽  
Corrosion Of Steel ◽  
Physical And Chemical ◽  
Secondary Chemical ◽  
And Diffusion

AbstractPhysical and chemical processes are responsible for the alkali-silica reaction in concrete. Physical processes include (i) migration of hydroxyl and alkali ions (ii) swelling by water imbibition of the alkali-silica gel produced, (iii) development of cracks. Chemical processes involve (i) neutralisation of acidic silanol groups and attack of siloxane bridges, both by OH- ions (ii) formation of an alkali silicate. These reactions result in a breakdown in the silica structure and diffusion of some silicate and impregnate the cement paste filling the capillary pores. The increase in permeability due to the opening and progression of cracks facilitates secondary chemical deteriorations like the formation of ettrinqite, carbonation and corrosion of steel reinforcement. Recent studies have emphasized the role of Ca(OH)2 preventing the dissolution or miqration of freed silica out of the structure. Only the removal of Ca(OH)2 is able to stop the expansion of concrete.The paper will present some new interpretations of alkali-silica reaction related to the diffusivity of various ions from the pore solution.

scholarly journals Water Flow, Solute and Heat Transfer in Groundwater

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1851 ◽  
Author(s):  
Alexander Yakirevich
Keyword(s):  
Heat Transfer ◽  
Water Flow ◽  
Groundwater Protection ◽  
Groundwater Resources ◽  
Chemical Processes ◽  
Parameters Estimation ◽  
The Sustainable Development ◽  
Wide Range ◽  
Drinking Water Production ◽  
Physical And Chemical

Groundwater is an essential and vital water resource for drinking water production, agricultural irrigation, and industrial processes. The better understanding of physical and chemical processes in aquifers enables more reliable decisions and reduces the investments concerning water management. This Special Issue on “Water Flow, Solute and Heat Transfer in Groundwater” of Water focuses on the recent advances in groundwater dynamics. In this editorial, we introduce 12 high-quality papers that cover a wide range of issues on different aspects related to groundwater: protection from contamination, recharge, heat transfer, hydraulic parameters estimation, well hydraulics, microbial community, colloid transport, and mathematical models. By presenting this integrative volume, we aim to transfer knowledge to hydrologists, hydraulic engineers, and water resources planners who are engaged in the sustainable development of groundwater resources.

Ignition delays of biodiesel-diesel blends: Investigations into the role of physical and chemical processes

Fuel ◽  
2021 ◽  
Vol 303 ◽  
pp. 121251
Author(s):  
Phuong X. Pham ◽  
Nam V.T. Pham ◽  
Thin V. Pham ◽  
Vu H. Nguyen ◽  
Kien T. Nguyen
Keyword(s):  
Chemical Processes ◽  
Physical And Chemical

scholarly journals ALUMINIUM BRONZE. NANOSTRUCTURAL PROCESSES OF MELTING AND MOULDING

2018 ◽  
pp. 12-15
Author(s):  
E. I. Marukovich ◽  
V. Yu. Stetsenko
Keyword(s):  
Dissolved Oxygen ◽  
Chemical Processes ◽  
Adsorbed Oxygen ◽  
Aluminum Bronze ◽  
Aluminium Bronze ◽  
Physical And Chemical

It is shown that melting and molding of aluminum bronze are difficult physical and chemical processes. In them the major role is played by the centers of crystallization of dendrites of a a-phase, the a-phase nanocrystals dissolved and the adsorbed oxygen and hydrogen. The role of the modifying crystals of an intermetallid of ZrAl3 is reduced to reduction of concentration of the dissolved oxygen and hydrogen and an intensifi ation of process of coagulation of nanocrystals of a a-phase in the centers of crystallization of dendrites of a a-phase.

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