Designing π\pi-stacked molecular structures to control heat transport through molecular junctions

We propose and analyze a new way of using $\pi$ stacking to design molecular junctions that either enhance or suppress a phononic heat current, but at the same time remain conductors for an electric current. Such functionality is highly desirable in thermoelectric energy converters, as well as in other electronic components where heat dissipation should be minimized or maximized. We suggest a molecular design consisting of two masses coupled to each other with one mass coupled to each lead. By having a small coupling (spring constant) between the masses, it is possible to either reduce, or perhaps more surprisingly enhance the phonon conductance. We investigate a simple model system to identify optimal parameter regimes and then use first principle calculations to extract model parameters for a number of specific molecular realizations, confirming that our proposal can indeed be realized using standard molecular building blocks.Comment: 5 pages + supplemental material, 3 figure

Human-Readable and Machine-Readable Knowledge Bases Using Specialized Word Processors

The maintenance of knowledge bases is one of the crucial activities in the life cycle of knowledge systems. This paper describes an innovative approach to write complex and large knowledge bases using specialized word processors. According to this, a knowledge model is represented as a conventional document that is written following the standard operations of word processors. Following this approach, domain experts that are not familiar with computer languages could easier read and write complex knowledge models. In addition to that, the processor is able of interpreting the content of the document to automatically perform tasks of the knowledge model. The paper describes the basic characteristics of the document and its specialized word processor and presents our experience following this approach for a knowledge system in the domain of hydrology

KATS: A Knowledge Acquisition Tool Based on Electronic Document Processing

This paper describes a particular knowledge acquisition tool for the construction and maintenance of the knowledge model of an intelligent system for emergency management in the field of hydrology. This tool has been developed following an innovative approach directed to end-users non familiarized in computer oriented terminology. According to this approach, the tool is conceived as a document processor specialized in a particular domain (hydrology) in such a way that the whole knowledge model is viewed by the user as an electronic document. The paper first describes the characteristics of the knowledge model of the intelligent system and summarizes the problems that we found during the development and maintenance of such type of model. Then, the paper describes the KATS tool, a software application that we have designed to help in this task to be used by users who are not experts in computer programming. Finally, the paper shows a comparison between KATS and other approaches for knowledge acquisition

Quantum Interference in Off-Resonant Transport through Single Molecules

We provide a simple set of rules for predicting interference effects in off-resonant transport through single-molecule junctions. These effects fall in two classes, showing respectively an odd or an even number of nodes in the linear conductance within a given molecular charge state, and we demonstrate how to decide the interference class directly from the contacting geometry. For neutral alternant hydrocarbons, we employ the Coulson-Rushbrooke-McLachlan pairing theorem to show that the interference class is decided simply by tunneling on and off the molecule from same, or different sublattices. More generally, we investigate a range of smaller molecules by means of exact diag- onalization combined with a perturbative treatment of the molecule-lead tunnel coupling. While these results generally agree well with GW calculations, they are shown to be at odds with simpler mean-field treatments. For molecules with spin-degenerate ground states, we show that for most junctions, interference causes no transmission nodes, but argue that it may lead to a non-standard gate-dependence of the zero-bias Kondo resonance.Comment: 12 pages, 7 figure

The U(1) Lattice Gauge Theory Universally Connects All Classical Models with Continuous Variables, Including Background Gravity

We show that the partition function of many classical models with continuous degrees of freedom, e.g. abelian lattice gauge theories and statistical mechanical models, can be written as the partition function of an (enlarged) four-dimensional lattice gauge theory (LGT) with gauge group U(1). This result is very general that it includes models in different dimensions with different symmetries. In particular, we show that a U(1) LGT defined in a curved spacetime can be mapped to a U(1) LGT with a flat background metric. The result is achieved by expressing the U(1) LGT partition function as an inner product between two quantum states.Comment: Published version, 31 pages, 12 figures; references update

Unseen and unheard? Women managers and organizational learning

This paper aims to use (in)visibility as a lens to understand the lived experience of six women managers in the headquarters of a large multinational organization in the UK to identify how “gender” is expressed in the context of organizational learning. Design/methodology/approach: The researchers take a phenomenological approach via qualitative data collection with a purposeful sample – the six female managers in a group of 24. Data were collected through quarterly semi-structured interviews over 12 months with the themes – knowledge, interaction and gender. Findings: Organizations seek to build advantage to gain and retain competitive leadership. Their resilience in a changing task environment depends on their ability to recognize, gain and use knowledge likely to deliver these capabilities. Here, gender was a barrier to effective organizational learning with women’s knowledge and experience often unseen and unheard. Research limitations/implications: This is a piece of research limited to exploration of gender as other, but ethnicity, age, social class, disability and sexual preference, alone or in combination, may be equally subject to invisibility in knowledge terms; further research would be needed to test this however. Practical implications: Practical applications relate to the need for organizations to examine and address their operations for exclusion based on perceived “otherness”. Gendered organizations cause problems for their female members, but they also exclude the experience and knowledge of key individuals as seen here, where gender impacted on effective knowledge sharing and cocreation of knowledge. Social implications: The study offers further evidence of gendered organizations and their impacts on organizational effectiveness, but it also offers insights into the continues social acceptance of a masculinized normative model for socio-economic practice. Originality/value: This exploration of gender and organizational learning offers new insights to help explain the way in which organizational learning occurs – or fails to occur – with visibility/invisibility of one group shaped by gendered attitudes and processes. It shows that organizational learning is not gender neutral (as it appears in mainstream organizational learning research) and calls for researchers to include this as a factor in future research

The “Space Between”: Situated Professional Development to Enhance 4-H Educators’ Pedagogical Design Capacity for Effective Curriculum Enactment

Curricula are planned and written by curriculum developers; they serve as instructional guides for educators. Educators make adaptations to written curricula to meet learners’ needs and achieve intended learning outcomes. The efficacy of curriculum adaptations is enhanced when educators have a high pedagogical design capacity, which can be improved through effective professional development. Lesson study is a model of situated professional development centered around ongoing improvement of curriculum enactment. Educators work collaboratively to make curriculum modifications and data-driven decisions to improve their teaching practices. Lesson study occurs at regular intervals over an extended duration

Self-management support intervention for parents of children with developmental disorders: The role of gratitude and hope

Objectives: Many parents of children with developmental disabilities, including autism spectrum disorders and attention deficit disorders, experience poor well-being and increased anxiety and depression. Very few interventions directly target parents’ needs. The peer-delivered HOPE Programme was designed to address this with six weekly group sessions focusing on self-management skills, including goal setting and expressing gratitude. Methods: This pre-post study aimed to examine changes in anxiety, depression, well-being, hope and gratitude, and to explore associations between changes in anxiety and depression and changes in gratitude and hope. Validated measures of depression, anxiety, positive well-being, gratitude and hope were used. Parents of children with a range of developmental disabilities, most commonly autism spectrum disorders, were recruited. Results: Of 137 (86.9% female) recruited, 108 parents completed the course and post-course data. Parents’ depression, anxiety, well-being, gratitude and hope all significantly improved between baseline and post-course. Hope and gratitude correlated significantly with depression, anxiety and well-being. Baseline depression, baseline gratitude, post-course hope and gratitude explained 50% of the variance in post-course depression. Reduced work hours, and baseline and post-course hope and gratitude explained 40% of the variance in post-course well-being. Anxiety was not associated to hope nor gratitude at either time point. Conclusions: This study provides initial support for feasibility and potential effect of the peer delivered self-management intervention on parental anxiety and depression. Changes in gratitude and hope account for some change in depression, but not anxiety. A randomised controlled trial is needed to establish efficacy and explore mechanisms of change in-depth