Search results for "Stability."
showing 10 items of 3015 documents
Beta-Decay Half-Lives and Neutron-Emission Probabilities of Very Neutron-Rich Y to Tc Isotopes
1996
Neutron-rich {sub 39}Y to {sub 43}Tc isotopes have been produced by fission of uranium with a 50MeV H{sub 2}{sup +} beam. Beta-decay half-lives, delayed neutron-emission probabilities, and production yields have been measured and compared with theory. Beta decay of 4 new isotopes is reported, and the {beta}-delayed neutron-emission mode has been discovered for 12 isotopes of the elements niobium and technetium. The results compared to quasiparticle random phase approximation predictions indicate the increasing importance of fast {beta} transitions to high-lying states of nuclei with large neutron excess. {copyright} {ital 1996 The American Physical Society.}
Change and stability of sense of coherence in adulthood: Longitudinal evidence from the Healthy Child study
2007
Abstract The main aim of this three-wave 35-year follow-up study among Finnish employees ( n = 532) was to investigate whether Sense of Coherence (SOC) is more stable among those with high SOC compared to those with low SOC, as hypothesized by Antonovsky [Antonovsky, A. (1987). Unraveling the mystery of health: how people manage stress and stay well. San Francisco, CA, US: Jossey-Bass], using two measurement points over 13 years. The participants were first studied in adolescence in 1961–1963, after which they responded to two postal questionnaires measuring SOC, first in 1985, and again in 1998. The results of the Factor Mixture Modeling identified two groups of individuals with different…
Effect of Mg2+ ions on competitive metal ions adsorption/desorption on magnesium ferrite : mechanism, reusability and stability studies
2021
The adsorption behavior of magnesium ferrite in single- and multicomponent metal ions solutions in the presence of Mg2+ ions were studied. A dramatic decrease in the adsorption capacity of magnesium ferrite towards Mn2+, Co2+, and Ni2+ ions for comparison study of single- and multicomponent solutions was established. The affinity of the sorbent in accordance with the maximum sorption capacities increases in the following order Cu2+ > Co2+ > Ni2+ > Mn2+. High efficiency of magnesium ferrite regeneration (~100%) with aqueous solutions of magnesium chloride in the concentration range of 0.001-0.1 M was shown. The low degree of toxic metal ions desorption combined with XRD, IR spectroscopy, and…
Sequential dissociation of insulin amyloids probed by high pressure Fourier transform infrared spectroscopy
2012
High Pressure (HP) Fourier Transform Infrared Spectroscopy (FTIR) has been here employed to investigate the thermodynamic stability of bovine pancreatic insulin (BPI) amyloids. Once the aggregation reaction has started, the backbone arrangement of the proteins forming the amyloid is known to reach a stationary phase in few hours; after this time the infrared absorption of fibrils becomes stable. It is here shown how the further stabilization of the structure during the stationary phase can be probed via FTIR spectroscopy, through the observation of the high pressure behaviour of fibrils formed at different maturation stages. We report on the high pressure fragmentation of insulin amyloids, …
La resistenza di interfaccia calcestruzzo poroso-terreni a grana fina per il consolidamento di pendii mediante trincee drenanti profonde
2022
Le trincee drenanti profonde rappresentano uno dei metodi più efficaci per la mitigazione del rischio da frana, in pendii con falda idrica. Esse sono realizzate mediante pannelli o pali secanti. Il riempimento è costituito di calcestruzzo poroso o materiale granulare. Se le trincee sono adeguatamente “innestate” nel terreno stabile e il materiale di riempimento ha sufficiente resistenza e rigidezza come il calcestruzzo poroso, si ha ulteriore in-cremento di resistenza a taglio per effetto shear keys, oltre a quello derivante dalla riduzione delle pressioni in-terstiziali. L’incremento di resistenza è dovuto sia alla resistenza all’interfaccia calcestruzzo–terreni sia a quella intrinseca del…
Age-Related Differences in Intermuscular Coherence EMG-EMG of Ankle Joint Antagonist Muscle Activity during Maximal Leaning
2022
Background: Intermuscular synchronization is one of the fundamental aspects of maintaining a stable posture and is of great importance in the aging process. This study aimed to assess muscle synchronization and postural stabilizer asymmetry during quiet standing and the limits of stability using wavelet analysis. Intermuscular synchrony and antagonistic sEMG-sEMG (surface electromyography) coherence asymmetry were evaluated in the tibialis anterior and soleus muscles. Methods: The study involved 20 elderly (aged 65 ± 3.6) and 20 young (aged 21 ± 1.3) subjects. The task was to perform a maximum forward bend in a standing position. The prone test was divided into three phases: quiet standing …
Reforming the international financial and monetary system: from Keynes to Davidson and Stiglitz
2004
International audience; With the usual debates trumpeting the usual merits of fixed versus flexible exchange rates, or some various incarnations thereof, the authors draw attention to Keynes's original plan for an international clearing union. The paper takes a close look at Joseph Stiglitz's recent suggestions to deal with financial crises along with Paul Davidson's Keynes-Post Keynesian clearinghouse. In the former case, the analysis is left wanting: the author offers nothing more than simple solutions to a system in need of dramatic changes. On the other hand, Davidson's analysis of the current state of affairs requires more than mere "plumbing" and addresses the root causes of the crise…
Quantitative Runge Approximation and Inverse Problems
2017
In this short note we provide a quantitative version of the classical Runge approximation property for second order elliptic operators. This relies on quantitative unique continuation results and duality arguments. We show that these estimates are essentially optimal. As a model application we provide a new proof of the result from \cite{F07}, \cite{AK12} on stability for the Calder\'on problem with local data.
Determination of basic strenght of aliphatic amines through ion pair formation in some ionic liquid solutions
2010
To have an evaluation of the basic strength of aliphatic amines in ionic liquid solution, the stability constants relevant to the formation of amine/p-nitrophenol ion pairs were determined in different ionic liquids at 298 K. In particular, aliphatic (pyrrolidinium) and aromatic (imidazolium) ionic liquids were used. Imidazolium ions, bmim(+) and bm(2)im(+), having different hydrogen bond donor abilities were taken into account. Anions were chosen ([BF(4)(-)], [PF(6)(-)], and [NTf(2)(-)]; where NTf(2) = bis(trifluoromethansulfonyl)imide) showing different shape, size, and coordination ability. Several primary, secondary (cyclic or not), and tertiary amines were used to study the effect of a…
Dicationic organic salts: gelators for ionic liquids
2014
Diimidazolium and dipyrrolidinium organic salts were tested for their ability to gel both organic solvents and ionic liquids. Organic salts containing 1-(1-imidazolylmethyl)-3,5-di-(3'-octylimidazolylmethyl)-benzene and 1-(N-pyrrolidylmethyl)-3,5-di-(N,N-octylpyrrolidylmethyl)-benzene cations were used. In addition to the simple bromide anion, also dianions having a naphthalene core such as 1,5- and 2,6-naphthalenedisulfonate and 2,6-naphthalenedicarboxylate were taken into account. Gelation tests demonstrated that organic salts used were able to harden ionic liquids. The materials obtained were investigated for their thermal stability and also for electric conductivity properties using mic…