Responding to imposed job redesign : the evolving dynamics of work and identity in restructuring professional identity

Professionals are increasingly prevalent in organizations and are required to change their professional practice in response to requirements from employers. It is therefore important to understand how professionals respond when they are required to conduct work that does not match with their identity. We investigated this situation in an English public services organisation where a major work redesign initiative required professionals to engage in new tasks that they did not want to do. Based on our findings, we develop a process model of professional identity restructuring that includes the following four stages: (1) resisting identity change and mourning loss of previous work, (2) conserving professional identity and avoiding the new work, (3) parking professional identity and learning the new work, and (4) retrieving and modifying professional identity and affirming the new work. We contribute to the literature by showing how parking one’s professional identity facilitates the creation of liminal space, which enables the restructuring of one’s professional identity. Our model also explicates the dynamics between professional work and professional identity, showing how requirements for new professional work can lead to a new professional identity

Leadership Influence on Collective Teacher Efficacy in Multi-cultural Teams: A Mixed-Methods Study

As evidence for positive effects of collective teacher efficacy on student performance and teacher well-being grow, increasing efforts have been made worldwide to understand how teachers’ beliefs in the team’s capacity form in schools. This study adopts a mixed-methods approach; 90 teachers from seven international schools in China participated in the survey, and eight teachers from these schools joined focus group interviews. This paper seeks to understand the relationship between teachers’ perceptions of instructional school leadership and collective efficacy, and how individual leaders’ character strength of encouragement and structural factors, including school levels and cultural dimensions, affect the relationship. Quantitative results show a significant correlation between instructional school leadership and collective teacher efficacy. Power distance is a significant moderator in the relationship, but school-level and cultural dimension of collectivism are not. Although leaders’ character strength of encouragement is not a significant mediator in the influence of instructional school leadership on collective teacher efficacy, it significantly mediates the influence of collective efficacy on teachers’ perceptions of instructional school leadership. Focus group participants recognized leadership as a critical factor in the formation of collective teacher efficacy at the school level and identified four categories of leadership practices shaping the formation: Developing School Learning Climate, Defining School Mission, Supervising and Evaluating Instruction, and Leading by Example. Findings, study limitations, and implications for future research and practice are further discussed

Surface silanization of carbon nanofibers and nanotubes for altering the properties of epoxy composites

Diese Arbeit beschreibt die Oberflächenmodifizierung von Kohlenstoffnanofasern (CNFs) und mehrwandigen Kohlenstoffnanoröhren (MWCNTs) sowie die Eigenschaften von damit hergestellten Epoxid-Kompositen. Es wurden Korrelationen zwischen chemischen Oberflächenmodifizierungen und Kompositeigenschaften untersucht.Im ersten Teil wurden nach einer Oxidation zur Erzeugung von Carboxygruppen daran anknüpfend drei unterschiedliche Reaktionswege zur Silanisierung der oxidierten Oberflächen der nanoskaligen Kohlenstoffmaterialien untersucht: direkte Silanisierung mit 3-Glycidoxypropyltrimethoxysilan Reduktion der Carboxygruppen zu den alkoholischen Hydroxygruppen und Silanisierung mit 3-Aminopropyltrimethoxysilan3) Silanisierung mit 3-Isocyanatopropyltriethoxysilan und weitere Silanisierung mit 3-AminopropyltrimethoxysilanDie Oxidation sowie die Silanisierung der CNFs und MWCNTs wurden systematisch und detailliert anhand verschiedener analytisch-chemischer Methoden charakterisiert.Im zweiten Teil wurden CNFs oder MWCNTs in Epoxidharzen dispergiert und die physikalischen Eigenschaften der daraus hergestellten Nanokomposite beschrieben. So zeigten Epoxid-Komposite, die mit silanisierten CNFs versetzt wurden, verbesserte mechanische Eigenschaften. Auch die elektrische Leitfähigkeit der Epoxid-Komposite stieg mit zunehmendem Gehalt der Nanofüllstoffe, wobei die elektrische Leitfähigkeit von Epoxid-Kompositen mit silanisierten CNFs aufgrund der isolierenden Silanschicht niedriger war als die der Epoxid-Komposite mit unmodifizierten CNFs. Bei MWCNTs-Epoxid-Kompositen bewirkte die Silanisierung eine größere Änderung der elektrischen Leitfähigkeit im Vergleich zu den CNFs-Epoxid-Kompositen. Das Einbringen von CNFs in das Epoxidharz erhöhte die thermische Leitfähigkeit. Die Wärmeleitfähigkeit der Epoxid-Komposite konnte in Abhängigkeit von der Silanmenge auf den CNFs höher oder niedriger sein als die der Epoxid-Komposite mit unmodifizierten CNFs. Die MWCNTs in den Epoxid-Kompositen konnten durch Anlegen eines elektrischen Wechselstromfeldes parallel zu den Feldlinien ausgerichtet werden, was Messungen einer anisotropen elektrischen Leitfähigkeit an den Kompositen belegten.Die nasschemische Silanisierung der nanoskaligen Kohlenstoffmaterialien stellt eine vielseitige und einfache Methode dar, die Eigenschaften von Polymerkompositen gezielt zu modifizieren. Diese Änderungen der Materialeigenschaften wurden dann vor allem durch stärkere Wechselwirkungen an den Grenzflächen zwischen Füllstoffen und Polymer sowie durch eine bessere Verteilung der Füllstoffe in der Polymermatrix erreicht.Surface silanization of carbon nanofibers (CNFs) and multi-walled nanotubes (MWCNTs) was carried out to investigate its effect on properties of epoxy composites. Unlike previous researches which worked mainly on the silanization of carbon nanotubes (CNTs), the focus of this thesis was the silanization of oxygenated CNFs with alkoxysilanes. However, oxygenated MWCNTs were also silanized as a comparison. In the first part, different oxidations were applied on CNFs and MWCNTs to find the optimal condition to introduce carboxyl groups on the surface. Three silanization procedures were performed on oxidized CNFs: 1) direct silanization with 3-glycidoxypropyltrimethoxysilane 2) first reduction of carboxyl groups on oxidized CNFs into alcoholic hydroxyl groups and then silanization with 3-aminopropyltrimethoxysilane 3) initially silanization with 3-isocyanatopropyltriethoxysilane and then a further silanization with 3-aminopropyltrimethoxysilane The procedure 2) was also performed on oxidized MWCNTs. The oxidation as well as the silanization of CNFs and MWCNTs was characterized systematically and explicitly by various analytical methods. In the second part, epoxy nanocomposites with CNFs or MWCNTs were prepared. Silanized CNFs improved the mechanical properties of composites. The electrical conductivity of composites was increased with the addition of fillers, but silanized CNFs/epoxy composites demonstrated smaller increments than original CNFs/epoxy composites due to the insulating silane coating on the CNF surface. Silanization has a greater effect on changing the electrical conductivity of MWCNTs/epoxy composites than CNFs/epoxy composites. The thermal conductivity of epoxy composites was also improved by the infusion of CNFs. Depending on the amount of silanes on CNFs, the thermal conductivity of epoxy composites with silanized CNFs could be higher or lower than that of composites with original CNFs. Epoxy composites with aligned MWCNTs could be prepared under alternating current electric field, which was confirmed by the anisotropy in the electrical conductivity of composites.The silanization of carbon nanofillers provides a facile way to adjust the properties of polymer composites by strengthening the interfacial interaction between fillers and polymer matrices as well as improving the dispersion of fillers in the matrix

Scattering Center Extraction and Recognition Based on ESPRIT Algorithm

Inverse Synthetic Aperture Radar (ISAR) generates high quality radar images even in low visibility. And it provides important physical features for space target recognition and location. This thesis focuses on ISAR rapid imaging, scattering center information extraction, and target classification. Based on the principle of Fourier imaging, the backscattering field of radar target is obtained by physical optics (PO) algorithm, and the relation between scattering field and objective function is deduced. According to the resolution formula, the incident parameters of electromagnetic wave are set reasonably. The interpolation method is used to realize three-dimensional (3D) simulation of aircraft target, and the results are compared with direct imaging results. CLEAN algorithm extracts scattering center information effectively. But due to the limitation of resolution parameters, traditional imaging can’t meet the actual demand. Therefore, the super-resolution Estimation of Signal Parameters via Rotational Invariance Techniques (ESPRIT) algorithm is used to obtain spatial target location information. The signal subspace and noise subspace are orthogonal to each other. By combining spatial smoothing method with ESPRIT algorithm, the physical characteristics of geometric target scattering center are obtained accurately. In particular, the proposed method is validated on complex 3D aircraft targets and it proves that this method is applied to most scattering mechanisms. The distribution of scattering centers reflects the geometric information of the target. Therefore, the electromagnetic image to be recognized and ESPRIT image are matched by the domain matching method. And the classification results under different radii are obtained. In addition, because the neural network can extract rich image features, the improved ALEX network is used to classify and recognize target data processed by ESPRIT. It proves that ESPRIT algorithm can be used to expand the existing datasets and prepare for future identification of targets in real environments. Final a visual classification system is constructed to visually display the results

Budget transparency and internal revenue mobilisation at sub-national government level: evidence from Nigeria

Internal revenue mobilisation by governments at the sub-national level has been low in Nigeria. In view of the rise in the level of budget transparency at the subnational level in recent times, this study examines the hypothesis that improved budget transparency leads to greater revenue mobilisation. The study adopts both cross-sectional and panel regression analyses based on data for 2015, 2018 and 2020. The findings suggest that the hypothesis that improved budget transparency improves revenue mobilisation cannot be rejected, but population density (urbanisation), poverty and unemployment are the dominant factors that explain revenue mobilisation by the state governments in Nigeria. The study also reiterates the need to control corruption in order to make sustainable progress in revenue mobilisation at sub-national level