Surface quality studies of high Tc_{c} superconductors of the Hg , Tl and Hgx_{x}Tl1−x_{1-x}-families: RBS and resonant C and O backscattering studies

The composition, crystallinity, uniformity, purity, and thermal stability of cuprate superconductors have been studied by Rutherford backscattering and channeling spectrometry, and 3.045 MeV He$^{+}$ oxygen non-Rutherford resonant scattering. Further experiments have been performed with 1.75 MeV H$^{+}$carbon non-Rutherford resonant scattering. Three sets of samples were studied : HgBa$_{2}$CuO$_{(4+\delta)}$ (Hg1201), Hg$_{x}$T1$_{1-x}$Ba$_{2}$Ca$_{2}$Cu$_{3}$O$_{(2n+\delta)}$ (Hg,T1-1223) and T1$_{1.85}$Ba$_{2}$CuO$_{6}$/LaA10$_{3}$ (T1-2201), either in bulk or as an epitaxial thin film. It was observed that the superconductors exhibit a metal deficiency near the surface, which is largely compensated by excess oxygen. Moreover, the samples are significantly contaminated with carbon within the probing region of the H$^+$ beam. The thermal stability and surface degradation were studied in both oxidizing ambient and vacuum. As a general trend, the heavy metal deficiency — and consequently the compensating oxygen excess — is enhanced as the temperature increases

Realising local government visions for developing district heating: experiences from a learning country

District heating (DH) has an important role to play in enabling cities to transition to low-carbon heating. Although schemes are commonplace in some countries, in ‘learning countries’ where building-level technologies make up the majority of heating systems there are numerous barriers to introducing DH. Local governments are seen as key actors in helping to create a ‘shared vision’ for DH amongst stakeholders. This study uses interviews with stakeholders from a range of sectors in the UK (an example of a learning country) to examine the visions of local actors for developing DH and the types of national policy that would support local implementation of these visions. The analysis shows that in engaging with DH development local governments seek multiple types of value. Realising this value will most likely happen by taking a long-term, planned approach to development. In contrast, national government policy is geared towards techno-economic criteria and may lead to only a minority of potential sites being developed, without realisation of wider social or environmental benefits aligned to local visions. The work highlights the importance of local strategic planning, enabled by aligned national policy, in realising the full economic, environmental and social benefits of DH

Room Temperature Electrochemical Synthesis of Hg-1212 Superconducting Thin Films

In the present investigation, the novel two-step electrochemical process of room temperature synthesis of Hg-1212 superconducting films has been developed and reported first time. Electrochemical parameters were optimized by studying cyclic voltammetry (CV), linear sweep voltammetry (LSV) and chronoamperometry (CA) for the deposition of Hg-Ba-Ca-Cu alloy at room temperature. Current time transient showed progressive growth with hemispheriodal granules, which were then revealed by scanning electron microscopy (SEM). Stoichiometric electrocrystallization to get Hg1Ba2Ca1Cu2O6+x (Hg-1212) was completed by electrochemically intercalating oxygen species into Hg-Ba-Ca-Cu alloy at room temperature. The oxygen content in the samples was varied by varying the electrochemical oxidation period and the changes in the crystal structure, microstructure, and superconducting transition temperature (Tc) and critical current density (Jc) were recorded. The films oxidized for 28 min showed Tc = 104.7 K with Jc = 1.437 x 103 A/cm2. The dependence of superconducting parameters on oxygen content is correlated with structure property relations and reported in this paper.Comment: 39 pages, 17 figures. Submitted to Physica

Kontraktsstyrning i teori och praktik

The general aim of this thesis is to develop an increased understanding of contract management as a mode of governance. A specific aim has been to explore how complex municipal services are managed by contract. A framework for analysis of contract management was developed by combining elements from interorganisational theories with different perspectives, such as transaction cost theories, network theories, and sociological institutional theories. The framework was applied in empirical studies of contract management of technical services in local authorities in Sweden, England and Germany. A follow-up study was carried out after four years. The empirical findings revealed a mixture of different governance mechanisms. Competition and conditionality were combined with trust and continuity. Detailed specifications and formal contracts were combined with a flexible and problem-solving approach to variations. Local agreements were combined with standardised contract conditions. Short contracts were combined with long-term relationships. There were differences in the style of contract management between large and small organisations, between stable services and services characterised by uncertainty and risk, and between countries with different societal systems. The style of management changed significantly within four years, from a stronger emphasis on price competition and adversial pressure to an emphasis on quality and partnership. A general conclusion is that contract management can be regarded as a mixture of governance mechanisms of opposite character, creating a balance of co-operation and competition. It is proposed that formal procedures can be seen as enhancing the evolution of trust in complex relationships. This contradicts the common view of formalism as an obstacle and opposing feature to trust. The use of standard contract conditions also indicates that contract relationships are partially constructed at an aggregate level. This confirms that contract management has to be analysed in a societal context. The general change of style of contract management within four years indicates that there might be general patterns of contract management, which change over time

Valkompetens i arbetslinjens tjänst - diskursiva föreställningar om valkompetens bland studie- och yrkesvägledare på gymnasiet

Syftet med examensarbetet är att undersöka och synliggöra hur studie- och yrkesvägledare på gymnasieskolan talar om den valkompetenta eleven och den icke-valkompetenta eleven, samt vad valkompetensen tillskrivs för betydelse. I förlängningen är även syftet att synliggöra hur studie- och yrkesvägledarens profession kan förstås ur ett samhälleligt perspektiv. Studien har en socialkonstruktivistisk utgångspunkt och använder diskursanalys av intervjuer med studie- och yrkesvägledare på gymnasieskolan som metod. Frågeställningarna är: (1) Hur konstrueras den valkompetenta och icke-valkompetenta eleven av sex studie- och yrkesvägledare på gymnasieskolan? (2) Hur konstruerar studie- och yrkesvägledare på gymnasiekolan vad valkompetensen ska åstadkomma och förhindra? (3) Hur konstruerar studie- och yrkesvägledare på gymnasiekolan ansvaret för att eleverna utvecklar valkompetents? (4) Vilken samhällelig funktion kan studie- och yrkesvägledaren på gymnasiet tillskrivas utifrån den diskurs som framträder i studiens material? Studien har identifierat hur valkompetens definieras av intervjupersonerna, vilket utgörs av ett antal förmågor och egenskaper. Vem som tillskrivs och inte tillskrivs besitta dessa förmågor redogörs för, och synliggör därmed vilka elever som antas vara i störst behov av att utveckla valkompetens. De konstruerade konsekvenserna av bristande valkompetens identifieras som ohälsa och att fastna på jobb. Studie- och yrkesvägledare positioneras som medansvarig för valkompetensutvecklingen hos elever, tillsammans med eleven själv och lärare likaså, och i hög grad rektorer, beslutsfattare och utbildningssystemens utformning. Studie- och yrkesvägledare kan förstås som en institutionell upprätthållare av Arbetslinjen