Thermoelectric power in one-dimensional Hubbard model

The thermoelectric power S is studied within the one-dimensional Hubbard model using the linear response theory and the numerical exact-diagonalization method for small systems. While both the diagonal and off-diagonal dynamical correlation functions of particle and energy current are singular within the model even at temperature T>0, S behaves regularly as a function of frequency $\omega$ and T. Dependence on the electron density n below the half-filling reveals a change of sign of S at n_0=0.73+/-0.07 due to strong correlations, in the whole T range considered. Approaching half-filling S is hole-like and can become large for U>>t although decreasing with T.Comment: 6 pages, 4 figure

On the Synthesis of and Magnetic Measurements on Xenon Tetrafluoride

Recently the synthesis of XeF4 was reported from the Argonne Nationlll Laborato·ry, and some of its physical properties were given1• In order to obtalin further information on this extraordinarily interesting compound XeF4 was prepared in our laboratory. Siince the details of the synthesis were not available the direct fluorination was performed under pressure at 400°C. The basic .idea was to obtain the maximum possible amount of the product in a small v.ol\u27l.lllle. The p.roduct was identified by mass spectroscopic analysis2 • The X-ray pattern was taken and the magnetic susceptibility was also measured. At present the NMR spectra are al!so under investigatioiil

Uber die Synthese von XeFa

Vergleichen wir di e Ergebnisse unserer Synthese von XeF,1 1 mit den anderen unabhangigen Resultaten ub er dieselbe Xe-Verbindung2,a,4 (die im allgemeinen gut iibereinstimmen), so finden wir doch Unterschiede, die unsere Vermutung, d a.ss s ich bei unseren Bedingungen der Synthese noch hohere Xe-Fluoride bilden, bestatigen. Wahrend namlich das Verhalt nis F: Xe in d en P raparaten uber die die amer ikanischen Authoren berichteten , zwischen 5,76 und 6 ,0 variiert, ist das Verha l tnis in unseren Praparaten 5,8 bis 6,4

Uber die Synthese von XeFa

Vergleichen wir di e Ergebnisse unserer Synthese von XeF,1 1 mit den anderen unabhangigen Resultaten ub er dieselbe Xe-Verbindung2,a,4 (die im allgemeinen gut iibereinstimmen), so finden wir doch Unterschiede, die unsere Vermutung, d a.ss s ich bei unseren Bedingungen der Synthese noch hohere Xe-Fluoride bilden, bestatigen. Wahrend namlich das Verhalt nis F: Xe in d en P raparaten uber die die amer ikanischen Authoren berichteten , zwischen 5,76 und 6 ,0 variiert, ist das Verha l tnis in unseren Praparaten 5,8 bis 6,4

On the Synthesis of and Magnetic Measurements on Xenon Tetrafluoride

Recently the synthesis of XeF4 was reported from the Argonne Nationlll Laborato·ry, and some of its physical properties were given1• In order to obtalin further information on this extraordinarily interesting compound XeF4 was prepared in our laboratory. Siince the details of the synthesis were not available the direct fluorination was performed under pressure at 400°C. The basic .idea was to obtain the maximum possible amount of the product in a small v.ol\u27l.lllle. The p.roduct was identified by mass spectroscopic analysis2 • The X-ray pattern was taken and the magnetic susceptibility was also measured. At present the NMR spectra are al!so under investigatioiil

Uber die Synthese von XeF6

Claassen und Mitarb.1 berlichten iiber die Syinthese von XeF4 , R. Hoppe und Mifarb.2 iiber die Synthese von XeF2 • Wir haiben die Synthese VO!!l XeF43 reproduzii.ert und koomten bei der massenspektrometrischen Analyse des Produktes schwache Andeutungen fiir die .Ainwesenheit hoherer Fluoride feststellen

From thermal rectifiers to thermoelectric devices

We discuss thermal rectification and thermoelectric energy conversion from the perspective of nonequilibrium statistical mechanics and dynamical systems theory. After preliminary considerations on the dynamical foundations of the phenomenological Fourier law in classical and quantum mechanics, we illustrate ways to control the phononic heat flow and design thermal diodes. Finally, we consider the coupled transport of heat and charge and discuss several general mechanisms for optimizing the figure of merit of thermoelectric efficiency.Comment: 42 pages, 22 figures, review paper, to appear in the Springer Lecture Notes in Physics volume "Thermal transport in low dimensions: from statistical physics to nanoscale heat transfer" (S. Lepri ed.

The impact of social networks on knowledge transfer in long-term care facilities: Protocol for a study

<p>Abstract</p> <p>Background</p> <p>Social networks are theorized as significant influences in the innovation adoption and behavior change processes. Our understanding of how social networks operate within healthcare settings is limited. As a result, our ability to design optimal interventions that employ social networks as a method of fostering planned behavior change is also limited. Through this proposed project, we expect to contribute new knowledge about factors influencing uptake of knowledge translation interventions.</p> <p>Objectives</p> <p>Our specific aims include: To collect social network data among staff in two long-term care (LTC) facilities; to characterize social networks in these units; and to describe how social networks influence uptake and use of feedback reports.</p> <p>Methods and design</p> <p>In this prospective study, we will collect data on social networks in nursing units in two LTC facilities, and use social network analysis techniques to characterize and describe the networks. These data will be combined with data from a funded project to explore the impact of social networks on uptake and use of feedback reports. In this parent study, feedback reports using standardized resident assessment data are distributed on a monthly basis. Surveys are administered to assess report uptake. In the proposed project, we will collect data on social networks, analyzing the data using graphical and quantitative techniques. We will combine the social network data with survey data to assess the influence of social networks on uptake of feedback reports.</p> <p>Discussion</p> <p>This study will contribute to understanding mechanisms for knowledge sharing among staff on units to permit more efficient and effective intervention design. A growing number of studies in the social network literature suggest that social networks can be studied not only as influences on knowledge translation, but also as possible mechanisms for fostering knowledge translation. This study will contribute to building theory to design such interventions.</p

Manufacture Techniques of Chitosan-Based Microcapsules to Enhance Functional Properties of Textiles

In recent years, the textile industry has been moving to novel concepts of products, which could deliver to the user, improved performances. Such smart textiles have been proven to have the potential to integrate within a commodity garment advanced feature and functional properties of different kinds. Among those functionalities, considerable interest has been played in functionalizing commodity garments in order to make them positively interact with the human body and therefore being beneficial to the user health. This kind of functionalization generally exploits biopolymers, a class of materials that possess peculiar properties such as biocompatibility and biodegradability that make them suitable for bio-functional textile production. In the context of biopolymer chitosan has been proved to be an excellent potential candidate for this kind of application given its abundant availability and its chemical properties that it positively interacts with biological tissue. Notwithstanding the high potential of chitosan-based technologies in the textile sectors, several issues limit the large-scale production of such innovative garments. In facts the morphologies of chitosan structures should be optimized in order to make them better exploit the biological activity; moreover a suitable process for the application of chitosan structures to the textile must be designed. The application process should indeed not only allow an effective and durable fixation of chitosan to textile but also comply with environmental rules concerning pollution emission and utilization of harmful substances. This chapter reviews the use of microencapsulation technique as an approach to effectively apply chitosan to the textile material while overcoming the significant limitations of finishing processes. The assembly of chitosan macromolecules into microcapsules was proved to boost the biological properties of the polymer thanks to a considerable increase in the surface area available for interactions with the living tissues. Moreover, the incorporation of different active substances into chitosan shells allows the design of multifunctional materials that effectively combine core and shell properties. Based on the kind of substances to be incorporated, several encapsulation processes have been developed. The literature evidences how the proper choices concerning encapsulation technology, chemical formulations, and process parameter allow tuning the properties and the performances of the obtained microcapsules. Furthermore, the microcapsules based finishing process have been reviewed evidencing how the microcapsules morphology can positively interact with textile substrate allowing an improvement in the durability of the treatment. The application of the chitosan shelled microcapsules was proved to be capable of imparting different functionalities to textile substrates opening possibilities for a new generation of garments with improved performances and with the potential of protecting the user from multiple harms. Lastly, a continuous interest was observed in improving the process and formulation design in order to avoid the usage of toxic substances, therefore, complying with an environmentally friendly approach