scholarly journals RSFit3000: A MATLAB GUI-based program for determining rate and state frictional parameters from experimental data

Geosphere ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 1665-1676 ◽  
Author(s):  
Rob M. Skarbek ◽  
Heather M. Savage

Abstract We present a MATLAB graphical user interface (GUI) software package for analyzing rate and state friction experiments. Called RSFit3000, the software allows users to easily determine frictional parameters by fitting velocity-step and slide-hold-slide events using the aging- and slip-law forms for state variable evolution. RSFit3000 includes features for removing strain hardening or weakening trends from the data, and provides options for using two state variables, applying a weighting function, and treating stiffness as a fitting parameter. Completed fits are conveniently saved in MATLAB structure arrays that contain fitted parameter values with their error intervals, and all information required to reproduce a given fit. The GUI makes the program simple to use, as all fitting tasks are completed via interaction with the interface. Here we describe how to use the software, and illustrate its flexibility and utility by analyzing two sets of synthetic friction data, as well as some previously published experimental data. Although descriptions of rate and state friction fitting routines have been published in the past, RSFit3000 marks the first time a software package for analyzing friction experiments has been described in the literature.

2010 ◽  
Vol 7 (3) ◽  
Author(s):  
Mahsa Behzadi ◽  
Aicha Demidem ◽  
Daniel Morvan ◽  
Laurent Schwartz ◽  
Georges Stepien ◽  
...  

SummaryWe study, in this paper, a model for the core of the system of the Glycerophospholipid metabolism in the murine cells. It comprises the simple and enzymatic reactions of PhosphatidylEthanolamine and the PhosphatidylCholine . The model’s general structure is taken from a number of books and articles. We translate this model into a set of ordinary differential equations (ODEs), to propose a quantitative explanation of the experimental experiences and the observed results. In order to make it usable as a basis for simulations and mathematical analysis we need to make precise the various constants present in the equations but which are usually not directly accessible in the literature. In a first step we considered experimental data of rat’s liver cells obtained by NMR spectroscopy: given the values of metabolite concentrations we find appropriate parameter values which allow us to describe the system with ODEs. We have then performed several analyses using the developed model such as stability analysis. A first interesting result is the global stability of the system which was observed by simulation and then proved by mathematical arguments. A second important result is that we observe on the diagrams that the steady state for normal cells is precisely a singular point of order two, whereas tumoral cells present different characteristics; this fact has been proved for PhosphatidylEthanolamine N-Methyl transferase (PEMT), an enzyme which seems to be identified for the first time as a crucial element in the tumoral process. In a second step we applied our model to experimental data of proton HRMAS NMR spectroscopy for solid B16 melanoma and Lewis lung (3LL) 3LL carcinoma cells treated by Chloroethyl Nitrosourea (CENU). We performed a complete comparative analysis of parameters in order to learn the predictive statements to explain increases and decreases which one can observe in concentrations.


Author(s):  
C.-L. Ng ◽  
K. A. Sallam

The deformation of laminar liquid jets in gaseous crossflow before the onset of primary breakup is studied motivated by its application to fuel injection in jet afterburners and agricultural sprays, among others. Three crossflow Weber numbers that represent three different liquid jet breakup regimes; column, bag, and shear breakup regimes, were studied at large liquid/gas density ratios and small Ohnesorge numbers. In each case the liquid jet was simulated from the jet exit and ended before the location where the experimental data indicated the onset of breakup. The results show that in column and bag breakup, the reduced pressures along the sides of the jet cause the liquid to move to the sides of the jet and enhance the jet deformation. In shear breakup, the flattened upwind surface pushes the liquid towards the two sides of the jet and causing the gaseous crossflow to separate near the edges of the liquid jet thus preventing further deformation before the onset of breakup. It was also found out that in shear breakup regime, the liquid phase velocity inside the liquid jet was large enough to cause onset of ligament formation along the jet side, which was not the case in the column and bag breakup regimes. In bag breakup, downwind surface waves were observed to grow along the sides of the liquid jet triggered a complimentary experimental study that confirmed the existence of those waves for the first time.


2020 ◽  
Vol 49 (D1) ◽  
pp. D325-D334
Author(s):  
◽  
Seth Carbon ◽  
Eric Douglass ◽  
Benjamin M Good ◽  
Deepak R Unni ◽  
...  

Abstract The Gene Ontology Consortium (GOC) provides the most comprehensive resource currently available for computable knowledge regarding the functions of genes and gene products. Here, we report the advances of the consortium over the past two years. The new GO-CAM annotation framework was notably improved, and we formalized the model with a computational schema to check and validate the rapidly increasing repository of 2838 GO-CAMs. In addition, we describe the impacts of several collaborations to refine GO and report a 10% increase in the number of GO annotations, a 25% increase in annotated gene products, and over 9,400 new scientific articles annotated. As the project matures, we continue our efforts to review older annotations in light of newer findings, and, to maintain consistency with other ontologies. As a result, 20 000 annotations derived from experimental data were reviewed, corresponding to 2.5% of experimental GO annotations. The website (http://geneontology.org) was redesigned for quick access to documentation, downloads and tools. To maintain an accurate resource and support traceability and reproducibility, we have made available a historical archive covering the past 15 years of GO data with a consistent format and file structure for both the ontology and annotations.


Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 219 ◽  
Author(s):  
Alberto Sanchez ◽  
Elías Todorovich ◽  
Angel de Castro

As the performance of digital devices is improving, Hardware-In-the-Loop (HIL) techniques are being increasingly used. HIL systems are frequently implemented using FPGAs (Field Programmable Gate Array) as they allow faster calculations and therefore smaller simulation steps. As the simulation step is reduced, the incremental values for the state variables are reduced proportionally, increasing the difference between the current value of the state variable and its increments. This difference can lead to numerical resolution issues when both magnitudes cannot be stored simultaneously in the state variable. FPGA-based HIL systems generally use 32-bit floating-point due to hardware and timing restrictions but they may suffer from these resolution problems. This paper explores the limits of 32-bit floating-point arithmetics in the context of hardware-in-the-loop systems, and how a larger format can be used to avoid resolution problems. The consequences in terms of hardware resources and running frequency are also explored. Although the conclusions reached in this work can be applied to any digital device, they can be directly used in the field of FPGAs, where the designer can easily use custom floating-point arithmetics.


Author(s):  
Giacomino Bandini ◽  
Paride Meloni ◽  
Massimiliano Polidori ◽  
Calogera Lombardo

The PERSEO experimental program was performed in the framework of a domestic research program on innovative safety systems with the purpose to increase the reliability of passive decay heat removal systems implementing in-pool heat exchangers. The conceived system was tested at SIET laboratories by modifying the existing PANTHERS IC-PCC facility utilized in the past for testing a full scale module of the GE-SBWR in-pool heat exchanger. Integral tests and stability tests were conducted to verify the operating principles, the steadiness and the effectiveness of the system. Two of the more representative tests have been analyzed with CATHARE V2.5 for code validation purposes. The paper deals with the comparison of code results against experimental data. The capabilities and the limits of the code in simulating such kind of tests are highlighted. An improvement in the modeling of the large water reserve pool is suggested trying to reduce the discrepancies observed between code results and test measurements.


2011 ◽  
Vol 26 (S2) ◽  
pp. 1893-1893
Author(s):  
I. Manor ◽  
G. Yazpan

ADHD is a well-known, chronic disorder that persists in adulthood. During the past 20 years its existence in adults is becoming clearer, yet its dynamic aspects are rarely discussed. The treatment of adults is vital, as much as that of children; however the literature discussing it, especially its non-pharmacological aspect, is scarce.We describe the results of our treatment with drama-therapy of two groups of adults with ADHD. These groups included 11 adults (from both groups), men and women, from most socioeconomic strata, aged ≥ 60 yrs., who were diagnosed as suffering from ADHD and were treated for it for the first time in their life. Drama-therapy was selected as we believed it to be a useful method with associative, distracted ADHD patients, since it enabled the use of transitional space through non-verbal images and acts.This presentation discusses the basic themes with which patients began therapy. Interestingly, all patients, however different, shared the same themes that were built on self doubt and the pre-presumption of disappointment. The impairment related to ADHD, that was felt, but not understood, led to a strong experience of heavy losses, which we tried to define separately: of a clear path, of control, of the inner perception of borders and of the loss of an integrative inner self. All these losses were accumulated in the transitional space in a place we named “Nowhere land”.We would like to present these themes of losses and of becoming lost and to discuss their meaning.


Exchange ◽  
1982 ◽  
Vol 11 (1) ◽  
pp. 48-57

AbstractMons. Antonio Batista Fragoso has been bishop of Crateus in Northeast Brazil for the past ten years. Eighty percent of the 360,000 people in his diocese are impoverished peasants who engage in rudimentary farming. At least half of the peasants are landless. It is among these people that Bishop Fragoso has encouraged the formation of small grassroots Christian communities that are responsible for a profound change in the patterns of Christian living in his diocese. The following is LP's translation of excerpts from a talk that Bishop Fragoso gave to his fellow bishops and priests in Managua in October, 1980. This is the first time it has appeared in English. (Editor Latinamerica Press)


2015 ◽  
Vol 370 (1681) ◽  
pp. 20140267 ◽  
Author(s):  
Paul J. Ferraro ◽  
Merlin M. Hanauer

To develop effective protected area policies, scholars and practitioners must better understand the mechanisms through which protected areas affect social and environmental outcomes. With strong evidence about mechanisms, the key elements of success can be strengthened, and the key elements of failure can be eliminated or repaired. Unfortunately, empirical evidence about these mechanisms is limited, and little guidance for quantifying them exists. This essay assesses what mechanisms have been hypothesized, what empirical evidence exists for their relative contributions and what advances have been made in the past decade for estimating mechanism causal effects from non-experimental data. The essay concludes with a proposed agenda for building an evidence base about protected area mechanisms.


2004 ◽  
Vol 19 (12) ◽  
pp. 3607-3613 ◽  
Author(s):  
H. Iikawa ◽  
M. Nakao ◽  
K. Izumi

Separation by implemented oxygen (SIMOX)(111) substrates have been formed by oxygen-ion (16O+) implantation into Si(111), showing that a so-called “dose-window” at 16O+-implantation into Si differs from Si(100) to Si(111). In SIMOX(100), an oxygen dose of 4 × 1017/cm2 into Si(100) is widely recognized as the dose-window when the acceleration energy is 180 keV. For the first time, our work shows that an oxygen dose of 5 × 1017/cm2 into Si(111) is the dose-window for the formation of SIMOX(111) substrates when the acceleration energy is 180 keV. The difference between dose-windows is caused by anisotropy of the crystal orientation during growth of the faceted buried SiO2. We also numerically analyzed the data at different oxidation velocities for each facet of the polyhedral SiO2 islands. Numerical analysis results show good agreement with the experimental data.


1990 ◽  
Vol 43 (7) ◽  
pp. 131-151 ◽  
Author(s):  
Sanda Cleja T¸igoiu ◽  
Eugen Soo´s

We present the microstructural basis, the initial macroscopical formulations, and a possible axiomatic reconstruction of the elastoviscoplastic model for metals based on the use of the local, current, relaxed configurations. Structural analysis and experimental data show that using these configurations offers advantages for the formulation of the material laws when the deformations are small or moderately large. Our review aims to be a concise, historical, and critical exposition of the main stages, contributions and results, which led, during the late sixties and the beginning of seventies, to the formulation of the fundamental ideas lying at the basis of the model. We delineate the role played by Lee, Liu, Teodosiu, Sidoroff, Mandel, and Kratochvil in the first formulation of the theory between 1966 and 1972, as well as the contributions of Dafalias and Loret to the development of the model between 1983 and 1985. Finally, we discuss some results obtained between 1985 and 1988 with models based on local current relaxed configurations.


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