Search results for "Small"
showing 10 items of 2441 documents
Supramolecular polymerization of electronically complementary linear motifs: anti-cooperativity by attenuated growth†
2021
Anti-cooperative supramolecular polymerization by attenuated growth exhibited by self-assembling units of two electron-donor benzo[1,2-b:4,5-b′]dithiophene (BDT) derivatives (compounds 1a and 1b) and the electron-acceptor 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) (compound 2) is reported. Despite the apparent cooperative mechanism of 1 and 2, AFM imaging and SAXS measurements reveal the formation of small aggregates that suggest the operation of an anti-cooperative mechanism strongly conditioned by an attenuated growth. In this mechanism, the formation of the nuclei is favoured over the subsequent addition of monomeric units to the aggregate, which finally results in short aggrega…
Synthesis of Fluorinated Bent-Core Mesogens (BCMs) Containing the 1,2,4-Oxadiazole Ring
2015
New fluorinated bent-core mesogens containing the 1,2,4-oxadiazole or 1,2,4-triazole nucleus have been synthesized taking advantage of the ANRORC (Addition of Nucleophile, Ring-Opening, Ring-Closure) reactivity of 5-perfluoroalkyl-1,2,4-oxadiazoles. Physical state changes of the obtained compounds were characterized through DSC, POM, and SAXS. Besides the formation of a smectic mesophase, a novel behavior as organic molecular glass was evidenced for some 1,2,4-oxadiazole derivatives.
SAXS Study on Myoglobin Embedded in Amorphous Saccharide Matrices
2011
We report on Small Angle X-ray Scattering (SAXS) measurements performed on samples of carboxy-myoglobin and met-myoglobin embedded in low hydrated matrices of four different saccharides (trehalose, sucrose, maltose and lactose). Results confirm the already reported occurrence of inhomogeneities, which are not peculiar of trehalose samples, but appear also in maltose and lactose, and in some cases also sucrose, being dependent on the sample hydration and on the presence of sodium dithionite. This behaviour confirms our previous interpretation about the nature of the inhomogeneities, and prompt it as a possible general behaviour for highly concentrated sugar matrices.
Further results on H<inf>&#x221E;</inf> control of switched linear time-delay systems
2012
In this note, we study the problems of stability analysis and H ∞ controller synthesis of discrete-time switched systems with time-varying delay. The system under consideration is firstly transformed into an interconnection system. Based on the system transformation and the scaled small gain theorem, the asymptotic stability of the original system is examined via the version of the bounded realness of the transformed forward system. The aim of the proposed approach is to reduce conservatism, which is made possible by a precise approximation of the time-varying delay and the input-output approach. The proposed stability condition is demonstrated to be much less conservative than most existin…
Fuzzy filter design for discrete-time delayed systems with distributed probabilistic sensor faults
2013
In this paper, the problem of distributed fuzzy filter design has been solved for T-S fuzzy systems with time-varying delays and multiple probabilistic packet losses. Our attention is paid to designing the distributed fuzzy filters to guarantee the filtering error dynamic system to be mean-square asymptotically stable with an average ℋ∞ performance. Sufficient conditions for the obtained filtering error dynamic system are proposed by applying a comparison model and the scaled small gain theorem. Based on the measurements and estimates of the system states for each sensor and its neighbors, the solution of the parameters of the distributed fuzzy filters is characterized in terms of the feasi…
Analytical Solutions of Viscoelastic Nonlocal Timoshenko Beams
2022
A consistent nonlocal viscoelastic beam model is proposed in this paper. Specifically, a Timoshenko bending problem, where size- and time-dependent effects cannot be neglected, is investigated. In order to inspect scale phenomena, a stress-driven nonlocal formulation is used, whereas to simulate time-dependent effects, fractional linear viscoelasticity is considered. These two approaches are adopted to develop a new Timoshenko bending model. Analytical solutions and application samples of the proposed formulation are presented. Moreover, in order to show influences of viscoelastic and size effects on mechanical response, parametric analyses are provided. The contributed results can be usefu…
Alternative energy storage options for heat pump water heater coupled with photovoltaic plant for domestic hot water production
2019
The present work relies on the topic of energy storage for Heat and Electricity applied to Heat Pump Water Heaters coupled with photovoltaic plants for Domestic Hot Water production. The main idea is to evaluate the possibility to exploit the water tank as heat storage for the produced photovoltaic energy and, where appropriate combined with electrical storage. For this reason, two heat pumps with different volume size have been chosen and smart control strategies have been applied while monitoring the water temperature in the tank. Calculations account on tapping profile inferred from monitored data of a representative end-user in a Mediterranean small island. Results show how the combinat…
Social cognition theories and behavior change in COVID-19: A conceptual review.
2022
The COVID-19 pandemic has had unprecedented health, economic, and social consequences worldwide. Although contact reductions and wearing face coverings have reduced infection rates, and vaccines have reduced illness severity, emergence of new variants of the coronavirus that causes COVID-19, and the shift from pandemic to endemic patterns of infection, highlights the importance of ongoing preventive behavior adherence to manage future outbreaks. Research applying social cognition theories may assist in explaining variance in these behaviors and inform the development of efficacious behavior change interventions to promote adherence. In the present article, we summarize research applying the…
Environmental Management Systems (Ems) - Control Instrument of the Impact of the Organization Activities on the Environment
2015
Abstract Due to the ability to create and use technology, the human being has found various ways to transform the resources of the Earth in all sorts of new materials, equipment and energy sources. At least since the last industrial revolution until now, each generation has added more technology to the received legacy, but at the same time, left the planet in a far more degraded state than the inherited condition. Within these changes, small and medium enterprises (SME) in their capacity as pillars of the economic development of a nation, have been compelled to change their previous strategies. Implementing an Environmental Management Systems (EMS) can be seen as the only way to connect the…
Les déterminants de la complexité des systèmes d’information comptables des dirigeants de PME : contingences culturelles et endogénéité
2018
Le premier objectif est d’étudier le lien entre les dimensions de la culture nationale et la complexité des systèmes d’information comptables (SIC) des dirigeants de PME. Le second est de contribuer au débat sur la présence potentielle de biais d’endogénéité dans les précédentes études réalisées sur le thème. Une régression multiple et un test d’Hausman ont été mobilisés en utilisant les réponses de 276 dirigeants de PME françaises, tunisiennes et syriennes. Les quatre dimensions de la culture proposées par Hofstede sont des déterminants significatifs de la complexité des SIC. Le test d’Hausman révèle que l’existence d’endogénéité est peu plausible.