Search results for "STABILITY"
showing 10 items of 3085 documents
Le due crisi: crisi del capitalismo e crisi ambientale. Una soluzione sostenibile?
2015
Le due crisi in titolo sono due facce di una stessa medaglia; e il tema verrà trattato su questa rivista in due parti divise solo al fine di agevolare la lettura. Nella Parte I si evidenzia come la crisi ambientale derivi dal generale rapporto di predazione e spoliazione delle risorse naturali, caratteristico del modo capitalistico di produzione e consumo; ancor più devastante nella sua attuale fase “iperliberista”. I danni sociali della crisi economica sono drammaticamente evidenti alla maggior parte dell’opinione pubblica – la critica alle attuali teorie e modelli economici sarà oggetto della Parte II – mentre le altrettanto drammatiche conseguenze della crisi ambientale faticano a diveni…
The Role of Covalent Functionalization in the Thermal Stability and Decomposition of Hybrid Layered Hydroxides
2020
The room temperature synthesis of two Co-based hybrid layered hydroxides containing the same organic ligand (suberate [Sub]), one connected through purely electrostatic interactions (CoAl layered double hydroxide [LDH]), and the other covalently functionalized (α-CoII simonkolleite phase) has been carried out. The magnetic properties exhibit an acute difference in the magnetization temperatures (from ≈10 K for the CoAl-LDH to ≈55 K for the α-CoII). Moreover, the role of the covalent functionalization in the thermal stability and the decomposition has been investigated by a forefront characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spect…
A new testing device for the role of the trunk in force production and in balance control in disabled sitting athletes
2017
In cross-country sit-skiing all athletes compete in a sitting position, but some of them have the ability to control their trunk more than others. The trunk plays an essential role in two performance determinants: propulsion generation and balance maintenance. The aim of the study is to design a new testing device assessing athletes’ responses to these propulsion determinants. The new device was composed of a seat surrounded by a sensorized aluminum frame. To assess propulsion generation, two force sensors were mounted in the anterior and posterior side of the frame, while two force sensors were embedded in two ropes elongated from the top of the frame. To measure trunk control, the device …
Cross-diffusion effects on stationary pattern formation in the FitzHugh-Nagumo model
2022
<p style='text-indent:20px;'>We investigate the formation of stationary patterns in the FitzHugh-Nagumo reaction-diffusion system with linear cross-diffusion terms. We focus our analysis on the effects of cross-diffusion on the Turing mechanism. Linear stability analysis indicates that positive values of the inhibitor cross-diffusion enlarge the region in the parameter space where a Turing instability is excited. A sufficiently large cross-diffusion coefficient of the inhibitor removes the requirement imposed by the classical Turing mechanism that the inhibitor must diffuse faster than the activator. In an extended region of the parameter space a new phenomenon occurs, namely the exis…
The stability of sense of coherence: comparing two age groups in a 5-year follow-up study
2003
In the original theoretical formulation, Antonovsky (1987a) proposed that sense of coherence is a developmental construct that becomes stabilized at the age of 30. The present 5-year follow-up study was designed to test this hypothesis by investigating the differences in stability in sense of coherence among two age groups the younger group of which consisted of individuals under and the older group of individuals over 30 years of age. The participants were Finnish technical designers (N=352) of whom 40% (n=141) comprised the younger age group (25–29 years) and 60% (n=211) the older age group (35–40 years). The 13-item Orientation to Life Questionnaire (Antonovsky, 1987a) was used to measur…
Long- and short-term in vitro D-dimer stability measured with INNOVANCE D-Dimer.
2009
Summary In vitro D-dimer stability in plasma is widely assumed, but has not yet been documented by systematic studies using samples covering a wide range of D-dimer. We investigated the short- and long-term stability of D-dimer in clinical citrated plasma samples with normal and pathological levels. The short-term stability was analysed by measuring D-dimer fresh, after storage of plasma for 4 hours at room temperature (RT) and after an additional 24 h storage at +2 to +8°C (n=40). Long-term stability samples (n=40) were measured fresh and after storage for 19, 25 and 36 months at ≤-60°C. The effect of repeated freezing was analysed by measuring samples (n=50) fresh and after four consecuti…
Complexity traits and synchrony of cryptocurrencies price dynamics
2021
AbstractIn this study, we characterized the dynamics and analyzed the degree of synchronization of the time series of daily closing prices and volumes in US$ of three cryptocurrencies, Bitcoin, Ethereum, and Litecoin, over the period September 1,2015–March 31, 2020. Time series were first mapped into a complex network by the horizontal visibility algorithm in order to revel the structure of their temporal characters and dynamics. Then, the synchrony of the time series was investigated to determine the possibility that the cryptocurrencies under study co-bubble simultaneously. Findings reveal similar complex structures for the three virtual currencies in terms of number and internal composit…
Design of stable mixed-metal MIL-101(Cr/Fe) materials with enhanced catalytic activity for the Prins reaction
2020
[EN] This work highlights the benefit of designing mixed-metal (Cr/Fe) MOFs for enhanced chemical stability and catalytic activity. A robust and stable mixed-metal MIL-101(Cr/Fe) was prepared through a HF-free direct hydrothermal route with Fe(3+)content up to 21 wt%. The incorporation of Fe(3+)cations in the crystal structure was confirmed by(57)Fe Mossbauer spectrometry. The catalytic performance of the mixed metal MIL-101(Cr/Fe) was evaluated in the Prins reaction. MIL-101(Cr/Fe) exhibited a higher catalytic activity compared to MIL-101(Cr), improved chemical stability compared to MIL-101(Fe) and a higher catalytic activity for bulky substrates compared to MIL-100(Fe).In situinfra-red sp…
X‐irradiation induced photo‐ and thermostimulated luminescence of CsCdF 3 :Mn crystals
2005
Photo- and thermostimulated luminescence (PSL and TSL respectively) of previously X-irradiated CsCdF3 crystal doped with Mn were investigated. After X-irradiation of CsCdF3 crystal at 8 K PSL bands at about 300 nm and 550 nm appear. Several stimulation bands can be revealed for luminescence at 300 nm and 550 nm. The stimulation band at 340 nm is related to an F-type centre absorption band in accordance with the Mollwo-Ivey relation for halide crystals. Subsequent heating of the crystal after X-irradiation at 8 K shows TSL peaks in the temperature regions 8 K – 90 K and 200 K – 300 K. The spectral composition of the TSL involves both bands at 300 nm and 550 nm. Experiments performed allow us…
Computational stability of an initially radial solution of a growth/dissolution problem in a nonradial implementation
1991
We consider a free boundary problem modelling the growth/dissolution of a crystal. The aim is to investigate the following question: Does the solution to the crystal growth problem posed in two dimensions with radially symmetric initial and boundary condition evolve as a radially symmetric solution?