scholarly journals Pb2+–Calcite Interactions under Far-from-Equilibrium Conditions: Formation of Micropyramids and Pseudomorphic Growth of Cerussite

2018 ◽  
Vol 122 (4) ◽  
pp. 2238-2247 ◽  
Author(s):  
Ke Yuan ◽  
Vincent De Andrade ◽  
Zhange Feng ◽  
Neil C. Sturchio ◽  
Sang Soo Lee ◽  
...  
Keyword(s):  
Equilibrium Conditions ◽  
Far From Equilibrium ◽  
Pseudomorphic Growth

Al-Sm Alloys Under Far-From-Equilibrium Conditions

2021 ◽  
pp. 85-91
Author(s):  
Can Okuyucu ◽  
Burçin Kaygusuz ◽  
Cemil Işıksaçan ◽  
Onur Meydanoğlu ◽  
Amir Motallebzadeh ◽  
...  
Keyword(s):  
Equilibrium Conditions ◽  
Far From Equilibrium

scholarly journals Non-Equilibrium Ionization in Puppis A

1983 ◽  
Vol 101 ◽  
pp. 245-252
Author(s):  
P. F. Winkler ◽  
C. R. Canizares ◽  
B. C. Bromley
Keyword(s):  
High Resolution ◽  
Spectroscopic Data ◽  
Supernova Remnant ◽  
Optical Data ◽  
Equilibrium Conditions ◽  
X Ray ◽  
Flux Measurements ◽  
Far From Equilibrium ◽  
Einstein Observatory ◽  
Non Equilibrium

High resolution X-ray spectroscopy of the brightest knot of emission in the Puppis A supernova remnant shows that it is made up of ionizing plasma, far from equilibrium. Flux measurements in several X-ray lines enable us to determine the non-equilibrium conditions: electron temperature, ion populations, and time since the knot was heated by the supernova shock. Imaging and spectroscopic data from the Einstein Observatory together suggest that this knot is a cloud of density about 10 cm−3 which has recently been shocked to a temperature 7 × 106 K. Radio and optical data on the region appear consistent with this picture.

scholarly journals How and why kinetics, thermodynamics, and chemistry induce the logic of biological evolution

2017 ◽  
Vol 13 ◽  
pp. 665-674 ◽  
Author(s):  
Addy Pross ◽  
Robert Pascal
Keyword(s):  
Present Report ◽  
Biological Evolution ◽  
Evolutionary Process ◽  
Second Law ◽  
Equilibrium Conditions ◽  
Chemical Systems ◽  
Dynamic Kinetic Stability ◽  
Far From Equilibrium ◽  
Self Organisation

Thermodynamic stability, as expressed by the Second Law, generally constitutes the driving force for chemical assembly processes. Yet, somehow, within the living world most self-organisation processes appear to challenge this fundamental rule. Even though the Second Law remains an inescapable constraint, under energy-fuelled, far-from-equilibrium conditions, populations of chemical systems capable of exponential growth can manifest another kind of stability, dynamic kinetic stability (DKS). It is this stability kind based on time/persistence, rather than on free energy, that offers a basis for understanding the evolutionary process. Furthermore, a threshold distance from equilibrium, leading to irreversibility in the reproduction cycle, is needed to switch the directive for evolution from thermodynamic to DKS. The present report develops these lines of thought and argues against the validity of a thermodynamic approach in which the maximisation of the rate of energy dissipation/entropy production is considered to direct the evolutionary process. More generally, our analysis reaffirms the predominant role of kinetics in the self-organisation of life, which, in turn, allows an assessment of semi-quantitative constraints on systems and environments from which life could evolve.

scholarly journals Planetary Nebulae with Massive Nuclei

1983 ◽  
Vol 103 ◽  
pp. 230-230
Author(s):  
R. Tylenda
Keyword(s):  
Thermal Structure ◽  
Planetary Nebulae ◽  
General Rule ◽  
Central Star ◽  
Time Dependent ◽  
Equilibrium Conditions ◽  
Ngc 7027 ◽  
Different Temperatures ◽  
Far From Equilibrium ◽  
Central Stars

Massive central stars (M > 1 Mo) of planetary nebulae burn nuclear fuel on a time scale of hundreds or tens of years which is shorter than the recombination time in a typical planetary nebula. Consequently the ionization and thermal structure of a nebula with such a nucleus is expected to be far from equilibrium conditions. The greatest chance of observing such a nebula is when the central star cools down to the white dwarf region. Time-dependent photoionization models suggest the following non-equilibrium effects to be expected at this stage. Firstly, the nebula shows a double shell structure, i.e. a bright, inner ring is surrounded by a faint, extended halo best seen in the HI lines and infrared lines from low-ionization species, such as (Ne II) 12.8 μ. Secondly, the low-excitation emission ((O II), (Ne II), (S III)) is enhanced relative to the high-excitation ((O III), (Ne III), (S III)). Thirdly, different modifications of the Zanstra method result in significantly different temperatures for the central star with a general rule that THI > THeII > THeII/HI The He II Zanstra method gives the most reliable result. Fourthly, the electron temperature derived from the (O III) lines is appreciably higher than that obtained from the (N II) lines. It is suggested that NGC 7027 and NGC 2440 possess massive central stars and that the above time-dependent effects are currently observed in these nebulae.

scholarly journals Nonlinear Pulsations of Luminous Blue Variables

2000 ◽  
Vol 176 ◽  
pp. 109-112
Author(s):  
Ernst A. Dorfl ◽  
Michael U. Feuchtinger ◽  
Alfred Gautschy
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Stellar Atmospheres ◽  
Radial Pulsation ◽  
Equilibrium Conditions ◽  
Stellar Radius ◽  
Luminous Blue Variables ◽  
Mass Ratios ◽  
Far From Equilibrium

AbstractWe present the results of various nonlinear radial pulsation calculations of LBVs with different luminosity to mass ratios. Depending on the stellar parameters, most of these objects undergo strongly non-adiabatic pulsations which can also modify their stellar atmospheres. In some cases part of the kinetic energy of the motions is transferred by shock waves into the atmospheric layers leading to an overall decrease or increase of the stellar radius. This results in different mean density accompanied by a change of the pulsational behavior which can be compared to the results of a linear stability analysis. We also find that regular pulsations can occur around a different equilibrium than the initial configuration which has been determined by stellar evolution calculations. In cases of even higher luminosity to mass ratios the linear stability analysis predicts several unstable modes and the nonlinear computations can exhibit rather irregular light curves. Due to the large non-adiabaticity of the pulsation the corresponding velocity curves still remain more regular, but show increasing amplitudes until the energy stored is released. The pulsations are far from equilibrium conditions and may also lead to a pulsationally driven mass loss for certain stellar parameters.

scholarly journals An experimental study of tremolite dissolution rates as a function of pH and temperature: Implications for tremolite toxicity and its use in carbon storage

2014 ◽  
Vol 78 (6) ◽  
pp. 1449-1464 ◽  
Author(s):  
Tamara Diedrich ◽  
Jacques Schott ◽  
Eric H. Oelkers
Keyword(s):  
Steady State ◽  
Absolute Temperature ◽  
Bet Surface Area ◽  
Release Rates ◽  
Dissolution Rates ◽  
Equilibrium Conditions ◽  
Exponential Factor ◽  
Near Surface ◽  
Far From Equilibrium ◽  
Aqueous Species

Steady-state tremolite dissolution rates, at far-from-equilibrium conditions, were measured as a function of aqueous silica and magnesium activity, pH from 1.9 to 6.7, and temperature from 25 to 150ºC. Calcium is released from tremolite faster than either Mg or Si throughout most of the experiments even after these latter elements attained steady-state release rates. The preferential removal of Ca releases fine Mg-Si rich needle-like fibres from the tremolite, probably promoting its toxicity. In contrast, Mg was released in stoichiometric or near to stoichiometric proportion to Si once steady-state was attained. Measured steady-state tremolite dissolution rates based on Si release can be described using where r+ signifies the BET surface area-normalized forward tremolite steady-state dissolution rate, AA refers to a pre-exponential factor = 6610–3 mol cm–2 s–1, EA designates an activation energy equal to 80 kJ mol–1, R represents the gas constant, T denotes absolute temperature, and ai refers to the activity of the subscripted aqueous species. This rate expression is consistent with tremolite dissolution rates at acidic pH being controlled by the detachment of partially liberated silica tetrahedra formed from the exchange of Mg2+ for two protons near the mineral surface after the near-surface Ca has been removed. Nevertheless, Mg release rates from tremolite are ~3 orders of magnitude slower than those from forsterite and enstatite suggesting that tremolite carbonation will be far less efficient than the carbonation of these other Mg-silicate minerals.

scholarly journals Sustainability at the Edge of Chaos: Its Limits and Possibilities in Public Health

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Christopher G. Hudson ◽  
Yvonne M. Vissing
Keyword(s):  
Public Health ◽  
Health Care ◽  
Complex Systems ◽  
Systems Theory ◽  
Equilibrium Conditions ◽  
Edge Of Chaos ◽  
Evaluative Criteria ◽  
Far From Equilibrium ◽  
Central Meaning ◽  
Policy And Planning

This paper critically reviews the expanding literature on applications of sustainability to healthcare policy and planning. It argues that the concept has been overgeneralized and has become a buzzword masking disparate agendas. It ignores the insights of the newest generation of systems theory on complex systems on the ubiquity of far-from-equilibrium conditions. Yet, a central meaning often ascribed to sustainability is the level continuation of healthcare programs and their institutionalization. Sustainability is only coherent in health care when it is more narrowly delimited to involve public health and treated as only one of several evaluative criteria that informs not only the continuation of programs but more often their expansion or contraction as needs dynamically change.

scholarly journals The dissolution behavior of borosilicate glasses in far-from equilibrium conditions

2018 ◽  
Vol 226 ◽  
pp. 132-148 ◽  
Author(s):  
James J. Neeway ◽  
Peter C. Rieke ◽  
Benjamin P. Parruzot ◽  
Joseph V. Ryan ◽  
R. Matthew Asmussen
Keyword(s):  
Dissolution Behavior ◽  
Borosilicate Glasses ◽  
Equilibrium Conditions ◽  
Far From Equilibrium
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