848 research outputs found
Nonequilibrium phase transitions and stationary state solutions of a three-dimensional random-field Ising model under a time dependent periodic external field
Nonequilibrium behavior and dynamic phase transition properties of a kinetic
Ising model under the influence of periodically oscillating random-fields have
been analyzed within the framework of effective field theory (EFT) based on a
decoupling approximation (DA). Dynamic equation of motion has been solved for a
simple cubic lattice () by utilizing a Glauber type stochastic process.
Amplitude of the sinusoidally oscillating magnetic field is randomly
distributed on the lattice sites according to bimodal and trimodal distribution
functions. For a bimodal type of amplitude distribution, it is found in the
high frequency regime that the dynamic phase diagrams of the system in
temperature versus field amplitude plane resemble the corresponding phase
diagrams of pure kinetic Ising model. Our numerical results indicate that for a
bimodal distribution, both in the low and high frequency regimes, the dynamic
phase diagrams always exhibit a coexistence region in which the stationary
state (ferro or para) of the system is completely dependent on the initial
conditions whereas for a trimodal distribution, coexistence region disappears
depending on the values of system parameters.Comment: 11 pages, 11 figure
Narcissus dubius, Narcisse Douteux
This species is endemic to southern France and eastern Spain. It is assessed as Least Concern because it has a widespread distribution, occurs in several protected areas throughout its range and its population is not expected to significantly decline in the near future. Further studies on the genetic structure of its population and trends in population size at global level are needed
Behavior of Reinforced Wall System During the 1999 Kocaeli (Izmit), Turkey, Earthquake
A four-span bridge together with a 10 m-high and 100 m-long bridge approach fill was one of the highway facilities damaged due to surface faulting along the Trans-European Motorway during 1999 Kocaeli Earthquake (Mw 7.4). The fault rupture crossed beneath an overpass bridge within a few meters away from the bridge abutment while damaging the approach fill which was reinforced with a double-faced mechanically stabilized earth wall (MSEW) system. The faulting-induced excessive tectonic ground deformations including near-field seismic shakings were the main sources of damage in the walls. Such effects, along with the others, caused cracks and panel separations in wall faces as a result of a liquefaction-induced differential settlement in the cross section. The performance of the reinforced walls was satisfactory that there was no significant structural damage despite the total collapse of the bridge decks. The wall system provided a unique case history under extreme loading conditions, while proving that they are flexible and can withstand large ground deformations. This paper discusses how the walls performed based on post-earthquake reconnaissance studies. The faulting activity, geology of the site, strong ground motions and damage states in the reinforced wall are discussed in details
Methodology for Evaluation of Seal-Coated, Gravel, and Dirt Roads
The objective of this research project was to develop methodologies for the evaluation of different types of seal-coated, gravel,
and dirt roads by using a best-practice-oriented pavement-management system in Illinois. A statewide survey comprised of 13
questions collected 133 responses from county engineers and highway commissioners. Many counties and townships in Illinois
performed similar practices to maintain seal-coated, gravel, and dirt roads. The subjective windshield surveys were often
conducted on a weekly basis to identify the most common distresses, such as potholes, rutting, and roadside drainage. Several
seal-coated, gravel, and dirt roads were evaluated using a field distress-survey manual method based on the newly developed
Seal-Coated Road Condition Index (SCRCI) and an Unsurfaced-Road Condition Index (URCI) that was adopted to measure surface
conditions of gravel and dirt roads. In addition, some of the commercially available cell phone applications, or apps, were
investigated for their effectiveness next to the use of a rolling or high-speed profilometer for assessing roughness conditions of
seal-coated, gravel, and dirt roads in this research study. Future research is recommended to fully establish guidelines about the
use of a cell phone app to be adopted by the Illinois Department of Transportation (IDOT) and for use by local agency officials in
Illinois. In conclusion, this research project established a database to develop a best-practice guide for effectively evaluating
unpaved roads maintained by local agencies.IDOT-R27-174Ope
Dynamic phase transition properties and hysteretic behavior of a ferrimagnetic core-shell nanoparticle in the presence of a time dependent magnetic field
We have presented dynamic phase transition features and stationary-state
behavior of a ferrimagnetic small nanoparticle system with a core-shell
structure. By means of detailed Monte Carlo simulations, a complete picture of
the phase diagrams and magnetization profiles have been presented and the
conditions for the occurrence of a compensation point in the system
have been investigated. According to N\'{e}el nomenclature, the magnetization
curves of the particle have been found to obey P-type, N-type and Q-type
classification schemes under certain conditions. Much effort has been devoted
to investigation of hysteretic response of the particle and we observed the
existence of triple hysteresis loop behavior which originates from the
existence of a weak ferromagnetic core coupling , as well as a
strong antiferromagnetic interface exchange interaction . Most
of the calculations have been performed for a particle in the presence of
oscillating fields of very high frequencies and high amplitudes in comparison
with exchange interactions which resembles a magnetic system under the
influence of ultrafast switching fields. Particular attention has also been
paid on the influence of the particle size on the thermal and magnetic
properties, as well as magnetic features such as coercivity, remanence and
compensation temperature of the particle. We have found that in the presence of
ultrafast switching fields, the particle may exhibit a dynamic phase transition
from paramagnetic to a dynamically ordered phase with increasing ferromagnetic
shell thickness.Comment: 12 pages, 12 figure
Durability of geothermal grouting materials considering extreme loads
The concern about the massive use of the non-renewable and very limited fossil fuels together with the well-known effects of the global warming makes it more necessary the efficient use of the current forms of renewable energy generation. Because of the crucial role played by the grouting materials in the Ground Source Heat Pumps (GSHP), a proper selection of these elements should be made based on a deep knowledge of their performance. In this paper, thermal conductivity, mechanical strength and grout-pipe permeability of four different highly workable grouts have been tested before and after they were subjected to wet-dry and freeze-thaw durability treatments. Results obtained demonstrated the harmful effects of using a large amount of mixing water in grouts subjected to those extreme loads. However, the use of these type of grouts with very good workability is still possible in GSHP installations with balanced thermal designs provided that regular operational and environment conditions are considered.The authors wish to express their gratitude to the Ministry of Economy and Competitiveness which funded this study within the Spanish National Plan for Scientific and Technical Research and Innovation (INNPACTO program) through the research project IPT-2011-0877-920000. The authors are also grateful to all the organizations and companies participating in this project: Sacyr Industrial, Universidad Politécnica de Madrid and Cype
Recommended from our members
Role and task recommendation and social tagging to enable social business process management
Traditional Business Process Management (BPM) poses a number of limitations for the management of ad-hoc processes, where the execution paths are not designed a priori and evolve during enactment. Social BPM, which predicates to integrate social software into the BPM lifecycle, has emerged as an answer to such limitations. This paper presents a framework for social BPM in which social tagging is used to capture process knowledge emerging during the enactment and design of the processes. Process knowledge concerns both the type of activities chosen to fulfil a certain goal and the skills and experience of users in executing specific tasks. Such knowledge is exploited by recommendation tools to support the design and enactment of future process instances. We first provide an overview of our framework, introducing the concepts of role and task recommendations, which are supported by social tagging. These mechanisms are then elaborated further by an example. Eventually, we discuss a prototype of our framework enabling collaborative process design and execution
Energy-Efficient Neuromorphic Architectures for Nuclear Radiation Detection Applications
A comprehensive analysis and simulation of two memristor-based neuromorphic architectures for nuclear radiation detection is presented. Both scalable architectures retrofit a locally competitive algorithm to solve overcomplete sparse approximation problems by harnessing memristor crossbar execution of vector–matrix multiplications. The proposed systems demonstrate excellent accuracy and throughput while consuming minimal energy for radionuclide detection. To ensure that the simulation results of our proposed hardware are realistic, the memristor parameters are chosen from our own fabricated memristor devices. Based on these results, we conclude that memristor-based computing is the preeminent technology for a radiation detection platform
Dynamic phase transition of the Blume-Capel model in an oscillating magnetic field
We employ numerical simulations and finite-size scaling techniques to
investigate the properties of the dynamic phase transition that is encountered
in the Blume-Capel model subjected to a periodically oscillating magnetic
field. We mainly focus on the study of the two-dimensional system for various
values of the crystal-field coupling in the second-order transition regime. Our
results indicate that the present non-equilibrium phase transition belongs to
the universality class of the equilibrium Ising model and allow us to construct
a dynamic phase diagram, in analogy to the equilibrium case, at least for the
range of parameters considered. Finally, we present some complementary results
for the three-dimensional model, where again the obtained estimates for the
critical exponents fall into the universality class of the corresponding
three-dimensional equilibrium Ising ferromagnet.Comment: 27 pages, 1 table, 15 figures, minor corrections (updated figures 3
and 4
- …