Theoretical study of magnetism, structure and chemical order in transition-metal alloy clusters

Research on transition-metal nanoalloy clusters composed of a few atoms is fascinating by their unusual properties due to the interplay among the structure, chemical order and magnetism. Such nanoalloy clusters, can be used to construct nanometer devices for technological applications by manipulating their remarkable magnetic, chemical and optical properties. Determining the nanoscopic features exhibited by the magnetic alloy clusters signifies the need for a systematic global and local exploration of their potential-energy surface in order to identify all the relevant energetically low-lying magnetic isomers. In this thesis the sampling of the potential-energy surface has been performed by employing the state-of-the-art spin-polarized density-functional theory in combination with graph theory and the basin-hopping global optimization techniques. This combination is vital for a quantitative analysis of the quantum mechanical energetics. The first approach, i.e., spin-polarized density-functional theory together with the graph theory method, is applied to study the Fe$_m$Rh$_n$ and Co$_m$Pd$_n$ clusters having $N = m+n \leq 8$ atoms. We carried out a thorough and systematic sampling of the potential-energy surface by taking into account all possible initial cluster topologies, all different distributions of the two kinds of atoms within the cluster, the entire concentration range between the pure limits, and different initial magnetic configurations such as ferro- and anti-ferromagnetic coupling. The remarkable magnetic properties shown by FeRh and CoPd nanoclusters are attributed to the extremely reduced coordination number together with the charge transfer from 3$d$ to 4$d$ elements. The second approach, i.e., spin-polarized density-functional theory together with the basin-hopping method is applied to study the small Fe$_6$, Fe$_3$Rh$_3$ and Rh$_6$ and the larger Fe$_{13}$, Fe$_6$Rh$_7$ and Rh$_{13}$ clusters as illustrative benchmark systems. This method is able to identify the true ground-state structures of Fe$_6$ and Fe$_3$Rh$_3$ which were not obtained by using the first approach. However, both approaches predict a similar cluster for the ground-state of Rh$_6$. Moreover, the computational time taken by this approach is found to be significantly lower than the first approach. The ground-state structure of Fe$_{13}$ cluster is found to be an icosahedral structure, whereas Rh$_{13}$ and Fe$_6$Rh$_7$ isomers relax into cage-like and layered-like structures, respectively. All the clusters display a remarkable variety of structural and magnetic behaviors. It is observed that the isomers having similar shape with small distortion with respect to each other can exhibit quite different magnetic moments. This has been interpreted as a probable artifact of spin-rotational symmetry breaking introduced by the spin-polarized GGA. The possibility of combining the spin-polarized density-functional theory with some other global optimization techniques such as minima-hopping method could be the next step in this direction. This combination is expected to be an ideal sampling approach having the advantage of avoiding efficiently the search over irrelevant regions of the potential energy surface.

Magnetic interactions between transition metal impurities and clusters mediated by low-dimensional metallic hosts: A first principles theoretical investigation

The magnetic properties and interactions between transition metal (TM) impurities and clusters in low-dimensional metallic hosts are studied using a first principles theoretical method. In the first part of this work, the effect of magnetic order in 3d-5d systems is addressed from the perspective of its influence on the enhancement of the magnetic anisotropy energy (MAE). In the second part, the possibility of using external electric fields (EFs) to control the magnetic properties and interactions between nanoparticles deposited at noble metal surfaces is investigated. The influence of 3d composition and magnetic order on the spin polarization of the substrate and its consequences on the MAE are analyzed for the case of 3d impurities in one- and two-dimensional polarizable hosts. It is shown that the MAE and easy- axis of monoatomic free standing 3d-Pt wires is mainly determined by the atomic spin-orbit (SO) coupling contributions. The competition between ferromagnetic (FM) and antiferromagnetic (AF) order in FePtn wires is studied in detail for n=1-4 as a function of the relative position between Fe atoms. Our results show an oscillatory behavior of the magnetic polarization of Pt atoms as a function of their distance from the magnetic impurities, which can be correlated to a long-ranged magnetic coupling of the Fe atoms. Exceptionally large variations of the induced spin and orbital moments at the Pt atoms are found as a function of concentration and magnetic order. Along with a violation of the third Hund’s rule at the Fe sites, these variations result in a non trivial behavior of the MAE. In the case of TM impurities and dimers at the Cu(111), the effects of surface charging and applied EFs on the magnetic properties and substrate-mediated magnetic interactions have been investigated. The modifications of the surface electronic structure, impurity local moments and magnetic exchange coupling as a result of the EF-induced metallic screening and charge rearrangements are analysed. In a first study, the properties of surface substitutional Co and Fe impurities are investigated as a function of the external charge per surface atom q. At large inter-impurity distances the effective magnetic exchange coupling ∆E between impurities shows RKKY-like oscillations as a function of the distance which are not significantly affected by the considered values of q. For distances r < 10 Å, important modifications in the magnitude of ∆E, involving changes from FM to AF coupling, are found depending non-monotonously on the value and polarity of q. The interaction energies are analysed from a local perspective. In a second study, the interplay between external EF effects, internal magnetic order and substrate-mediated magnetic coupling has been investigated for Mn dimers on Cu(111). Our calculations show that EF (∼ 1eV/Å) can induce a switching from AF to FM ground-state magnetic order within single Mn dimers. The relative coupling between a pair of dimers also shows RKKY-like oscillations as a function of the inter-dimer distance. Their effective magnetic exchange interaction is found to depend significantly on the magnetic order within the Mn dimers and on their relative orientation on the surface. The dependence of the substrate-mediated interaction on the magnetic state of the dimers is qualitatively explained in terms of the differences in the scattering of surface electrons. At short inter-dimer distances, the ground-state configuration is determined by an interplay between exchange interactions and EF effects. These results demonstrate that external surface charging and applied EFs offer remarkable possibilities of manipulating the sign and strength of the magnetic coupling of surface supported nanoparticles.

From evolution to co-evolution – An empirical study of the role of innovation, policy and public research in industrial dynamics

In the past decades since Schumpeter’s influential writings economists have pursued research to examine the role of innovation in certain industries on firm as well as on industry level. Researchers describe innovations as the main trigger of industry dynamics, while policy makers argue that research and education are directly linked to economic growth and welfare. Thus, research and education are an important objective of public policy. Firms and public research are regarded as the main actors which are relevant for the creation of new knowledge. This knowledge is finally brought to the market through innovations. What is more, policy makers support innovations. Both actors, i.e. policy makers and researchers, agree that innovation plays a central role but researchers still neglect the role that public policy plays in the field of industrial dynamics. Therefore, the main objective of this work is to learn more about the interdependencies of innovation, policy and public research in industrial dynamics. The overarching research question of this dissertation asks whether it is possible to analyze patterns of industry evolution – from evolution to co-evolution – based on empirical studies of the role of innovation, policy and public research in industrial dynamics. This work starts with a hypothesis-based investigation of traditional approaches of industrial dynamics. Namely, the testing of a basic assumption of the core models of industrial dynamics and the analysis of the evolutionary patterns – though with an industry which is driven by public policy as example. Subsequently it moves to a more explorative approach, investigating co-evolutionary processes. The underlying questions of the research include the following: Do large firms have an advantage because of their size which is attributable to cost spreading? Do firms that plan to grow have more innovations? What role does public policy play for the evolutionary patterns of an industry? Are the same evolutionary patterns observable as those described in the ILC theories? And is it possible to observe regional co-evolutionary processes of science, innovation and industry evolution? Based on two different empirical contexts – namely the laser and the photovoltaic industry – this dissertation tries to answer these questions and combines an evolutionary approach with a co-evolutionary approach. The first chapter starts with an introduction of the topic and the fields this dissertation is based on. The second chapter provides a new test of the Cohen and Klepper (1996) model of cost spreading, which explains the relationship between innovation, firm size and R&D, at the example of the photovoltaic industry in Germany. First, it is analyzed whether the cost spreading mechanism serves as an explanation for size advantages in this industry. This is related to the assumption that the incentives to invest in R&D increase with the ex-ante output. Furthermore, it is investigated whether firms that plan to grow will have more innovative activities. The results indicate that cost spreading serves as an explanation for size advantages in this industry and, furthermore, growth plans lead to higher amount of innovative activities. What is more, the role public policy plays for industry evolution is not finally analyzed in the field of industrial dynamics. In the case of Germany, the introduction of demand inducing policy instruments stimulated market and industry growth. While this policy immediately accelerated market volume, the effect on industry evolution is more ambiguous. Thus, chapter three analyzes this relationship by considering a model of industry evolution, where demand-inducing policies will be discussed as a possible trigger of development. The findings suggest that these instruments can take the same effect as a technical advance to foster the growth of an industry and its shakeout. The fourth chapter explores the regional co-evolution of firm population size, private-sector patenting and public research in the empirical context of German laser research and manufacturing over more than 40 years from the emergence of the industry to the mid-2000s. The qualitative as well as quantitative evidence is suggestive of a co-evolutionary process of mutual interdependence rather than a unidirectional effect of public research on private-sector activities. Chapter five concludes with a summary, the contribution of this work as well as the implications and an outlook of further possible research.

Tecnología industrial I : una ventana abierta a la investigación y experimentación en bachillerato.

Se presenta memoria final de proyecto educativo que propone la estructuración de los bloques temáticos de la asignatura de tecnología industrial I perteneciente al bachillerato tecnológico, a través de dos grandes centros de interés, uno de ellos estará basado en el azulejo sevillano y el otro en el aprovechamiento energético del sol. Se realiza en el IES Pablo Picasso en Sevilla. Los objetivos son: superar el anquilosamiento de un sistema excesivamente teórico; despertar el interés por el derecho que asiste a los pueblos a conocer a su cultura, valorando nuestro patrimonio tecnológico como bien social e irrenunciable; promover un proceso de aprendizaje en la línea de 'aprender a aprender'; aproximar al alumno a un contexto sociolocacional cultural de su entorno; despertar en el alumnado interés por la experimentación y la investigación; permitir un acercamiento globalizador o interdisciplinar con otras áreas; fomentar y ejercitar la creatividad, la capacidad de diseño, organización a nivel grupal e ingenio investigando y construyendo artilugios con materiales de desecho; habilitar a adquirir conocimientos también fuera del aula; descubrir con ambas propuestas las posibilidades de integración laboral; contribuir a que el alumnado tengan cabezas bien hechas que no bien llenas. El proceso consta de varias fases: aproximación, conocimiento, implicación y aportaciones; organización por grupos, asumir roles, directrices a seguir; concreción de contenidos; de desarrollo, salidas diversas, recogida de información; elaboración y organización de 'carpetas-dossier'; elaboración de documentos resumen; revisión y montaje de documentos definitivos; presentación de trabajos.

Lean Transition of Emerging Industrial Capability

This volume of the final report documents the technical work performed from December 1998 through December 2002 under Cooperative Agreement F33615-97-2-5153 executed between the U.S. Air Force, Air Force Research Laboratory, Materials and Manufacturing Directorate, Manufacturing Technology Division (AFRL/MLM) and the McDonnell Douglas Corporation, a wholly-owned subsidiary of The Boeing Company. The work was accomplished by The Boeing Company, Phantom Works, Huntington Beach, St. Louis, and Seattle; Ford Motor Company; Integral Inc.; Sloan School of Management in the Massachusetts Institute of Technology; Pratt & Whitney; and Central State University in Xenia, Ohio and in association with Raytheon Corporation. The LeanTEC program manager for AFRL is John Crabill of AFRL / MLMP and The Boeing Company program manager is Ed Shroyer of Boeing Phantom Works in Huntington Beach, CA. Financial performance under this contract is documented in the Financial Volume of the final report.

La escuela del paternalismo industrial asturiano (1880-1936).

Conocer la intervención escolar y las realizaciones educativas del empresario minero asturiano. Método de investigación descriptivo de tipo histórico y retrospectivo que trata de analizar la intervención escolar y las realizaciones educativas del empresario minero asturiano entre 1880 y 1936. Las fuentes documentales de análisis proceden de los archivos de la empresa estatal HUNOSA y la empresa privada Duro-Felguera (Asturias). En la historia de la escolarización en la Asturias contemporánea ha sido determinante la actuación del empresario minero. Esta investigación histórica contribuye a comprender las claves, el sentido y alcance de tal contribución, centrándose en el análisis de su intervención escolar y socioeducativa desde la década de los ochenta del siglo XIX hasta el término de la II República, abordando el despliegue del programa educativo del paternalismo industrial. Un programa que preseguía configurar el nuevo trabajador industrial, sustentándose en la 'filantropía científica', que aconsejaba al patrón ocuparse de las provisiones sociales que atiende en el tiempo de no trabajo de la población obrera y el tiempo escolar y no escolar de la infancia. Entre estas provisiones, la escuela del paternalismo industrial, respondiendo exclusivamente a criterios de política patronal, tendrá una funcionalidad disciplinante e ideológica llevada a cabo por distintas órdenes y congregaciones religiosas, que realizarán también una intervención moralizadora en el ocio infantojuvenil y adulto, desplegando hacia ambos colectivos instituciones y espacios específicos de sociabilidad. De esta doble dimensión se ocupa ampliamente este texto, procediendo igualmente a cuantificar y periodizar el desarrollo del mapa escolar patronal, así como a analizar su incidencia tanto en la propia ordenación del territorio industrial como en el desarrollo de la red escolar pública.

Projectes (Enginyeria Industrial) [versió html]

Aquest llibre ha de permetre desenvolupar els criteris que ens permeten d'establir la metodologia de treball que s'ha de seguir en la redacció de Projectes. Tant des del punt de vista d'organització i de gestió, (pràctica i tècnica) i ha de garantir un correcte coneixement de tots i cadascun dels conceptes que intervenen i que permeten d'assolir el producte final: un document redactat pel projectista que recull l'objectiu pel qual ens ha estat encarregat i apte per fer-ne una realitat

Lean Transition of Emerging Industrial Capability (LeanTEC)

Lean Transition of Emerging Industrial Capability (LeanTEC) program was a cooperative agreement between the Boeing Company and AFRL conducted from January 1998 to January 2002. The results of this program are documented in the Manual for Effective Technology Transition Processes included as an attachment to this report. This manual provides processes, procedures, and tools for greatly improving technology transition in the aerospace industry. Methodology for the implementation of these improvements is given along with methods for customizing the various processes, procedures, and tools for a given company or business unit. The indicated methodology was tested by the LeanTEC team and results are documented in the report.

Industrial Relations and "Humanware"

This is a preliminary paper. Please do not quote without the permission of the author. The research on which this paper is based has been conducted with the collaboration of John Paul MacDuffie, MIT. The researchers owe much to the warm cooperation of managers, employees, and union officials of Japanese auto companies and joint venture companies in the U.S. as well as American auto companies and the UAW. We would like to express our sincere appreciation for their assistance.

Projectes (Enginyeria Industrial) [versió comprimida]

Aquest llibre ha de permetre desenvolupar els criteris que ens permeten d'establir la metodologia de treball que s'ha de seguir en la redacció de Projectes. Tant des del punt de vista d'organització i de gestió, (pràctica i tècnica) i ha de garantir un correcte coneixement de tots i cadascun dels conceptes que intervenen i que permeten d'assolir el producte final: un document redactat pel projectista que recull l'objectiu pel qual ens ha estat encarregat i apte per fer-ne una realitat

Creativitat industrial: quinze anys de projectes

L'exposició Creativitat industrial vol ser un reconeixement a la tasca de les persones que han participat en els estudis de Disseny Industrial: estudiants, professors i empreses. Els estudis de Disseny Industrial i Desenvolupament de Producte de la Universitat de Girona fan quinze anys i, en aquest temps, han estat molts els projectes que s’han convertit en realitat

Professionals: L'experiència de la inserció laboral d'un enginyer industrial acabat de titular

Sóc Aleix Avalos Sans, enginyer industrial titulat a la Universitat de Girona. Vaig finalitzar els estudis el gener del 2007. En aquest escrit us explico la meva experiència professional com a recent titulat de la UdG incidint especialment en la meva participació en un conveni universitat-empresa mentre estava finalitzant els estudis, cosa que em va facilitar posteriorment la meva ràpida i adient inserció al món laboral

Projecte constructiu d’una nau industrial

Definició d’una nau industrial per a magatzem frigorífic mitjançant la memòria tècnica, els plànols i els càlculs ubicada al terme municipal de Begur (Baix Empordà)

La Felguera : un n??cleo de la revoluci??n industrial

Se trata de un trabajo complementario del v??deo del mismo t??tulo que consiste en unas explicaciones y una gu??a para la explotaci??n did??ctica del mismo. Se incluyen en ??l una ficha t??cnica del v??deo seguida de una explicaci??n del proyecto y de sus objetivos generales. A continuaci??n se adjunta una gu??a did??ctica dividida en siete apartados de trabajo correspondiendo a las secuencias del v??deo y, en una segunda parte, se adjunta el texto completo del v??deo seguido de la bibliograf??a utilizada. Se explican los or??genes y desarrollo urbano de La Felguera como resultado de la implantaci??n de la industria. Los objetivos comunes para la gu??a y el v??deo son: utilizar el entorno como recurso did??ctico, dar a conocer a los alumnos su realidad social y urban??stica y la funcionalidad de las Ciencias Sociales para analizar el entorno. No se ha pretendido hacer una unidad did??ctica sino m??s bien un tema hist??rico local que puede constitu??rse como eje de contenidos transversales, com??n a diversos bloques tem??ticos del dise??o curricular base.