Search results for "Diss"
showing 10 items of 2500 documents
Efficient ultraviolet-light energy dissipation by an aromatic ketone.
2010
Experimental evidence on the efficiency of 2,2'4,4'-tetramethoxybenzil for UV-light energy dissipation is provided. This non-phenolic aromatic ketone has a low energy triplet which quickly decays to the ketone ground state, thus avoiding the generation of undesirable reactive species. El Moncef, Abdelkarim, elmonab@alumni.uv.es ; Cuquerella Alabort, Maria Consuelo, Chelo.Cuquerella@uv.es ; Zaballos Garcia, Elena, Elena.Zaballos@uv.es ; Ramirez de Arellano Sanchez, Maria del Carmen, Carmen.Ramirezdearellano@uv.es ; Stiriba, Salah Eddine, Salah.Stiriba@uv.es ; Perez Prieto, Julia, Julia.Perez@uv.es
Current‐voltage curves of bipolar membranes
1992
Bipolar membranes consist of a layered ion‐exchange structure composed of a cation selective membrane joined to an anion selective membrane. They are analogous to semiconductor p‐n devices as both of them present current‐voltage curves exhibiting similar rectification properties. In this article, we present some current‐voltage curves obtained for different bipolar membranes at several temperatures. The results can be interpreted in terms of a simple model for ion transport and field‐enhanced water dissociation previously developed. The mechanism responsible for water splitting is assumed to be a catalytic proton transfer reaction between the charged groups and the water at the membrane int…
Temperature dependent mechanical unfolding of calixarene nanocapsules studied by molecular dynamics simulations.
2019
Using atomistic molecular dynamics simulations, we study the temperature dependence of the mechanical unfolding of a model supramolecular complex, a dimer of interlocked calixarene capsules. This system shows reversible transitions between two conformations that are stabilized by different networks of hydrogen bonds. We study the forced dissociation and formation of these networks as a function of temperature and find a strong impact of the nonequilibrium conditions imposed by pulling the system mechanically. The kinetics of the transition between the two conformations is ideally suited to investigate the range of validity of the stochastic models employed in the analysis of force dependent…
Fragmentation of polycarbonate macroinitiators in solution and in the bulk state
1990
The diphenylethane initiator 3,4-diethyl-3,4-(p-methoxyphenyl)-hexane (T–OCH3) was synthesized. By cocondensation of bisphenol A or C and the bisphenol derivative (“T”) of T–OCH3 with phosgene, polycarbonate macroinitiators PC(TxA1-x) and PC(TxC1-x) with different compositions x were made. The thermal fragmentation of T–OCH3 and the copolycarbonates was investigated with and without a radical scavenger both in solution and in the bulk state. The primary dissociation of T–OCH3 is a monomolecular Arrhenius process with a characteristic temperature of T* (τ = 1h) = 140°C (τ: average life time of the intact molecule). When the radicals are not intercepted, the dissociation is excessively revert…
The Relationship Between Aortic Root Size and Hypertension: An Unsolved Conundrum
2017
Thoracic aortic aneurysms rupture and dissection are among the most devastating vascular diseases, being characterized by elevated mortality, despite improvements in diagnostic imaging and surgical techniques. An increased aortic root diameter (ARD) represents the main risk factor for thoracic aortic dissection and rupture and for aortic valve regurgitation. Even though arterial hypertension is commonly regarded as a predisposing condition for the development of thoracic aorta aneurysms, the role of blood pressure (BP) as determinant of aortic root enlargement is still controversial. The use of different methods for indexation of ARD may have in part contributed to the heterogeneous finding…
Energy-efficient routing control algorithm in large-scale WSN for water environment monitoring with application to Three Gorges Reservoir area
2013
Published version of an article in the journal: The Scientific World Journal. Also available from the publisher at: http://dx.doi.org/10.1155/2014/802915 Open Access The typical application backgrounds of large-scale WSN (wireless sensor networks) for the water environment monitoring in the Three Gorges Reservoir are large coverage area and wide distribution. To maximally prolong lifetime of large-scale WSN, a new energy-saving routing algorithm has been proposed, using the method of maximum energy-welfare optimization clustering. Firstly, temporary clusters are formed based on two main parameters, the remaining energy of nodes and the distance between a node and the base station. Secondly,…
On the global dissipative and multipeakon dissipative behavior of the two-component Camassa-Holm system
2014
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2014/348695 Open Access The global dissipative and multipeakon dissipative behavior of the two-component Camassa-Holm shallow water system after wave breaking was studied in this paper. The underlying approach is based on a skillfully defined characteristic and a set of newly introduced variables which transform the original system into a Lagrangian semilinear system. It is the transformation, together with the associated properties, that allows for the continuity of the solution beyond collision time to be established, leading to a uniquely global d…
Stepping on invisible land: on the importance of communicating the value of soils.
2022
Soils play fundamental roles in the functioning of the Earth's ecosystems. Despite numerous initiatives to protect soils, it continues to be generally perceived as dirt or, at best, the surface we walk on. To better understand soil perception by the public, we conducted a survey with 99 participants from Poland and Brazil. We applied opportunity sampling and conducted semi-structured interviews with 40 respondents from Poland and 30 from Brazil, and 29 unstructured interviews in Brazil. Most of the respondents (53%) of the semi-structured interviews associated soil with the surface where plants grow, while 27% said that it is the ground we step on. When asked about pro-environmental campaig…
From measuring to revealing. 7 Paradigmatic actions for the construction of models as tools of representation
2017
L’esperienza maturata nel corso della ricerca: Progettazione, Organizzazione e Gestione di un nuovo Laboratorio di modellistica: metodologie, materiali e strumenti, (piani cazione, organizzazione e gestione di un nuovo laboratorio di modellazione: metodologie, materiali e strumenti), presso il Politecnico di Milano, è il background di questo articolo proposto per la giornata di studi. Da questa esperienza il testo si concentra sul set-up della seguente dichiarazione: il modello architettonico come strumento di rappresentazione. L’obiettivo è quello di formulare alcune procedure metodologiche, attraverso sette diverse azioni di progetto: scavo, taglio, piegatura, stratificazione, intaglio, m…
A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1
2020
The hydroxyl radical (OH) plays critical roles within the troposphere, such as determining the lifetime of methane (CH4), yet is challenging to model due to its fast cycling and dependence on a multitude of sources and sinks. As a result, the reasons for variations in OH and the resulting methane lifetime (τCH4), both between models and in time, are difficult to diagnose. We apply a neural network (NN) approach to address this issue within a group of models that participated in the Chemistry-Climate Model Initiative (CCMI). Analysis of the historical specified dynamics simulations performed for CCMI indicates that the primary drivers of τCH4 differences among 10 models are the flux of UV li…