Search results for " Programming"

Development of non-equilibrium Green's functions for use with full interaction in complex systems

2016

We present an ongoing development of an existing code for calculating groundstate, steady-state, and transient properties of many-particle systems. The development involves the addition of the full four-index two electron integrals, which allows for the calculation of transport systems, as well as the extension to multi-level electronic systems, such as atomic and molecular systems and other applications. The necessary derivations are shown, along with some preliminary results and a summary of future plans for the code. peerReviewed

Chromogenic and fluorogenic reagents for chemical warfare nerve agents' detection

2008

The ease of production, the extreme toxicity of organophosphorus-containing nerve agents, and their facile use in terrorism attacks underscores the need to develop accurate systems to detect these chemicals. Among different technologies we review here recent advances in the design of chromo-fluorogenic methods for the specific detection of nerve agents. Optical sensing (especially colorimetric detection) requires usually low-cost and widely used instrumentation and offers the possibility of so-called “naked eye detection”. Recent reported examples suggest that the application of chromo-fluorogenic supramolecular concepts for the chromogenic or fluorogenic sensing of nerve agents might be an…

Electro-organic Synthesis as a Sustainable Alternative for Dehydrogenative Cross-Coupling of Phenols and Naphthols

2016

The dehydrogenative cross-coupling of phenols and naphthols can be achieved by several oxidative methods. However, the key is the use of fluorinated alcohols such as 1,1,1,3,3,3-hexafluoroisopropanol. The direct application of electricity represents an alternative synthetic approach, which is superior to other oxidizers (e.g., peroxides). The method is sustainable, inherently safe, and easily scalable.

Magnetic exchange interaction in clusters of orbitally degenerate ions. I. Effective Hamiltonian

2001

Abstract A new effective Hamiltonian is reported for the kinetic exchange between two arbitrary terms 2S A +1 Λ A and 2S B +1 Λ B that can be ground or excited in octahedrally coordinated transition metal ions. This Hamiltonian is applicable to both homo- and heterometallic clusters. For the homonuclear cluster the resonance part of the effective Hamiltonian is also presented for the case when one of the ions is excited. The operator part of the exchange Hamiltonian contains symmetry adapted products of the cubic irreducible tensors acting in orbital spaces ΛA and ΛB and scalar product of site spin operators. The parameters of the Hamiltonian are defined by the relevant intercenter transfer…

Decision letter: Activity-dependent death of transient Cajal-Retzius neurons is required for functional cortical wiring

2019

Schools That ‘Open Doors’ to Prevent Child Abuse in Confinement by COVID-19

2020

Background: Due to the expected increase in child abuse during the period of COVID-19 confinement, it is essential that social researchers and other professionals work together very quickly to provide alternatives that protect children. To respond to this extremely urgent demand, evidence-based actions are presented that are being carried out in nine schools in the autonomous communities of Valencia and Murcia, Spain, during the confinement with the goal of “opening doors” to foster supportive relationships and a safe environment to prevent child abuse. Methods: The research was conducted through the inclusion of teachers who are implementing these actions in dialogue with the researchers t…

Description of the Retention and Peak Profile for Chromolith Columns in Isocratic and Gradient Elution Using Mobile Phase Composition and Flow Rate a…

2014

The effect of the modifier concentration and flow rate on the chromatographic performance of a second generation Chromolith® RP-18e column, under isocratic and gradient elution with acetonitrile-water mixtures, was examined using four sulphonamides as probe compounds. The acetonitrile concentration was varied between 5 and 55% (v/v), and the flow rate between 0.1 and 5.0 mL/min, keeping the other factors constant. The changes in both retention and peak profile were modelled, and used to build simple plots, where the logarithm of the retention factor was represented against the modifier concentration (in gradient elution, against the initial modifier concentration), and the half-widths or wi…

A Small Special Needs Class or a Smaller Class at the Beginning of the Educational Path?

2016

<p>This article is based on the case study which focuses on the small class (in this article used to describe a small special needs class) operation of one medium-sized Finnish town. In the study an attempt was made to clarify what kind of alternative the small class is to the first grade of general education at the beginning of the child's educational path, what kind of experiences the teachers had of the pupils of the small class, of multi-vocational cooperation and of pupils' integration and success in general education. The results of the study showed that a large part of the pupils who come to the small classes had learning difficulties, and attention and behavioural disorders. I…

The object-tool duality in mathematical modelling. A framework to analyze students’ appropriation of Sankey diagrams to model dynamic processes

2020

Students often do not experience the relevance of learning mathematics. This paper reports on an exploratory case study, in which a class of grade 8 students (n=35) was introduced to Sankey diagrams. The aim was to explore to what extent these students could appropriate Sankey diagrams, meaning: they could describe these as objects in themselves and they could use them to model and visualize phenomena relevant to them. Based on Cultural-Historical Activity Theory, we developed an analytical construct defined as the object-tool duality, coordinating mathematics as a set of objects and as a set of tools. The analysis of students’ answers showed that they could use these diagrams as tools to v…

Supporting Dispute Handling in E-Commerce Transactions, a Framework and Related Methodologies

2004

An E-commerce transaction is a means to conduct particular commercial activities using the global digital E-commerce infrastructure. We concentrate here on business to customer (B-to-C) E-commerce transactions. These transactions are based on protocols offered by the global infrastructure, primarily the Internet. Using electronic means to do business can greatly improve the efficiency of the business transactions. It, however, poses some problems that were rarely considered to be important before. One class of problems is caused by the behavior of untrusted participants. For reasons such as dishonesty, disputes may arise. In the general case, when a dispute arises an untrustworthy participa…