Search results for "Stability"

Tungsten(VI) complexes formed in an excess of gluconic acid: A polarimetric and spectrophotometric study

1985

The tungsten(VI)-gluconic acid system in an excess of this organic reagent has been spectroscopically and polarimetrically studied and four species, two mononuclear with stoichiometry 1∶2 (metal∶ligand) and two dinuclear with composition 2∶2, have been identified. The non-formation of a binuclear species with stoichiometry 2∶1 (metal∶ligand) demonstrates some preference towards coordination of carboxylate group.

Stability Analysis and Stabilization of T-S Fuzzy Delta Operator Systems with Time-Varying Delay via an Input-Output Approach

2013

Published version of an article in the journal: Mathematical Problems in Engineering. Also available from the publisher at: http://dx.doi.org/10.1155/2013/913234 Open Access The stability analysis and stabilization of Takagi-Sugeno (T-S) fuzzy delta operator systems with time-varying delay are investigated via an input-output approach. A model transformation method is employed to approximate the time-varying delay. The original system is transformed into a feedback interconnection form which has a forward subsystem with constant delays and a feedback one with uncertainties. By applying the scaled small gain (SSG) theorem to deal with this new system, and based on a Lyapunov Krasovskii funct…

Robust stability and stabilization of uncertain T-S fuzzy systems with time-varying delay: An input-output approach

2013

An input-output approach to the stability and stabilization of uncertain Takagi-Sugeno (T-S) fuzzy systems with time-varying delay is proposed in this paper. The time-varying parameter uncertainties are assumed to be norm-bounded, and the delay is intervally time varying. A novel method is employed to approximate the time-varying delay, based on which the considered system is transformed into a feedback interconnection form. The new formulation of the system is comprised of a forward subsystem with constant time delay and a feedback subsystem embedding the uncertainties. By applying the scaled small-gain theorem to the converted system, less conservative stability and stabilization criteria…

Input-Output Finite-Time Stability of Discrete-Time Impulsive Switched Linear Systems with State Delays

2013

Published version of an article in the journal: Circuits, Systems, and Signal Processing. Also available from the publisher at: http://dx.doi.org/10.1007/s00034-013-9610-7 This paper is concerned with the problem of input-output finite-time stability (IO-FTS) for discrete impulsive switched systems with state delays. Sufficient conditions are presented for the existence of IO-FTS for such systems under the cases of certain switching, arbitrary switching, and uncertain switching. All the obtained results are formulated in a set of linear matrix inequalities (LMIs). Two numerical examples are given to illustrate the effectiveness of the proposed results.

Domain shuffling between Vip3Aa and Vip3Ca: chimera stability and insecticidal activity against European, American, African, and Asian pests

2020

The bacterium Bacillus thuringiensis produces insecticidal Vip3 proteins during the vegetative growth phase with activity against several lepidopteran pests. To date, three different Vip3 protein families have been identified based on sequence identity: Vip3A, Vip3B, and Vip3C. In this study, we report the construction of chimeras by exchanging domains between Vip3Aa and Vip3Ca, two proteins with marked specificity differences against lepidopteran pests. We found that some domain combinations made proteins insoluble or prone to degradation by trypsin as most abundant insect gut protease. The soluble and trypsin-stable chimeras, along with the parental proteins Vip3Aa and Vip3Ca, were tested…

PERSISTENCE OF SOME PESTICIDES IN THE AQUATIC ENVIRONMENT

1992

Design characteristics, primary stability and risk of fracture of orthodontic mini-implants: Pilot scan electron microscope and mechanical studies

2013

Objectives: Orthodontic mini-implants (OMIs) are increasingly used in orthodontics but can fail for various reasons. This study investigates the effects of OMI design characteristics on the mechanical properties in artificial bone. Material and Methods: Twelve self-drilling OMIs (2 small, 6 medium, 4 large) from 8 manufacturers were tested for their primary stability in simulated medium-high cancellous bone and the risk to fracture in high-density methacrylate blocks. For the assessments of the maximum insertion torque (IT) and torsional fracture (TF) 5 of each OMI were used and for the pull-out strength (POS) 10. The OMIs were inserted with a torque screwdriver (12 sec/360°) until the bott…

Intersystem Crossing and Light-Induced Bistability in Iron(?) Spin-Crossover Compounds

1996

Abstract The dynamics of the high-spin→low-spin intersystem crossing process in iron(?) spin-crossover compounds are strongly influenced by cooperative effects of elastic origin which are due to the large difference in volume between high-spin and low-spin complexes. The deviation from first order kinetics is attributed to a build-up of an internal pressure as the relaxation proceeds, leading to a characteristic self-acceleration. The elastic interactions may lead to a light-induced bistability for systems which otherwise remain in the high-spin state down to cryogenic temperatures.

Model Exploration and Computer Experiments

2017

This chapter contains a description of a set of simulation experiments for exploration of the agent-based model proposed in the present work, devised to illustrate the model’s generative capacity and highlight the influence of the newly introduced mechanisms on the complexity of the solutions. The first experiment shows the influence of the critical “cop”-to-“active” ratio ρ c in the risk perception model on the size, duration, and recurrence of rebellion peaks. The relationship between ρ c , the occurrence of cascades and the maximum possible peak size was demonstrated analytically and then studied via computer simulations. It was shown that the value of ρ c has a strong impact on the stab…

Assessment of Osstell ISQ's reliability for implant stability measurement: a cross-sectional clinical study

2013

Resonance frequency analysis (RFA) allows assess implant stability by measuring implant oscillation frequency on the bone. RFA is an objective and non-invasive method for implant stability measurement, although scarce evidence has been provided so far on its reliability. Objectives: Assess the Osstell ISQ system's reliability (i.e., its measurement reproducibility and repeatability) by means of the intraclass correlation coefficient (ICC) as statistical method. Study Desing: Implants stability registers were completed by means of Osstell ISQ on 85 implants on 23 patients. Six measurements were completed on each implant by means of two different SmartPegs (types I and II); that is, three con…