48 research outputs found
Satisfying the Need for Relatedness Among Teachers: Benefits of Searching for Social Support
The satisfaction of teachers’ need for relatedness is an important pre-condition for teachers’ wellbeing. Receiving social support plays an important role in satisfying the need for relatedness. Following job crafting theory, the present study aims to examine (1) whether searching for social support results in an increase in the satisfaction of the need for relatedness and (2) whether this effect is mediated by an increase of received social support from the school principal and from colleagues. Using longitudinal data (N = 1071) we calculated residualized change scores and applied structural equation modeling to test the hypothesized mediation model. Results confirmed the beneficial effect of searching for social support on the satisfaction of the need for relatedness. This effect included a direct effect and an indirect effect through the receipt of social support from colleagues. The receipt of social support from the school principal was positively related to searching for social support but was unrelated to the satisfaction of the need for relatedness. These findings emphasize the importance that teachers build strong and supportive relationships within the school team, as this helps to satisfy their need for relatedness, which in turn contributes to better wellbeing among teachers
School principals’ social support and teachers’ basic need satisfaction: The mediating role of job demands and job resources
Many teachers report high levels of occupational stress. Teachers’ basic need satisfaction is essential for teachers’ well-being at work. Social support from school principals is assumed to play an important role for teachers’ basic need satisfaction. However, the underlying mechanisms of the relationship between social support from school principals and teachers’ basic need satisfaction are mostly unknown. Previous research suggests that job demands and job resources may play an important mediating role. Therefore, we examine whether teachers’ perceived job demands and job resources serve as mediators between social support from the school principal and teachers’ basic need satisfaction. Using longitudinal data of N = 1071 teachers over the course of one school year, we applied structural equation modelling to test the hypothesised mediation model. Results showed that the relationship between social support from the school principal and teachers’ basic need satisfaction was mediated by teachers’ perceived job demands and job resources. Particularly, the job demand ‘unclear organisational conditions’ and job resource ‘social support from colleagues’ indicated the strongest effects on teachers’ basic need satisfaction. These findings emphasise the responsibility of school principals to provide social support to their teachers and create a well-structured and supportive workplace. In doing so, school principals contribute to a work environment in which teachers can thrive
Ultrafast dynamics of the indoline dye D149 on electrodeposited ZnO and sintered ZrO2 and TiO2 thin films
The ultrafast photoinjection and subsequent relaxation steps of the indoline dye D149 were investigated in detail for a mesoporous electrodeposited ZnO thin film and compared with experiments on sintered TiO2 and ZrO2 thin films, all in contact with air, using pump-supercontinuum probe (PSCP) transient absorption spectroscopy in the range 370-770 nm. D149 efficiently injects electrons into the ZnO surface with time constants from ≤70 fs (time-resolution-limited) up to 250 fs, without the presence of slower components. Subsequent spectral dynamics with a time constant of 20 ps and no accompanying change in the oscillator strength are assigned to a transient Stark shift of the electronic absorption spectrum of D149 molecules in the electronic ground state due to the local electric field exerted by the D149 •+ radical cations and conduction band electrons in ZnO. This interpretation is consistent with the shape of the relaxed PSCP spectrum at long times, which resembles the first derivative of the inverted steady-state absorption spectrum of D149. In addition, steady-state difference absorption spectra of D149•+ in solution from spectroelectrochemistry display a bleach band with distinctly different position, because no first-order Stark effect is present in that case. Interference features in the PSCP spectra probably arise from a change of the refractive index of ZnO caused by the injected electrons. The 20 ps component in the PSCP spectra is likely a manifestation of the transition from an initially formed bound D149 •+-electron complex to isolated D149•+ and mobile electrons in the ZnO conduction band (which changes the external electric field experienced by D149) and possibly also reorientational motion of D149 molecules in response to the electric field. We identify additional spectral dynamics on a similar timescale, arising from vibrational relaxation of D149•+ by interactions with ZnO. TiO2 exhibits similar dynamics to ZnO. In the case of ZrO2, electron injection accesses trap states, which exhibit a substantial probability for charge recombination. No Stark shift is observed in this case. In addition, the spectroelectrochemical experiments for D149•+ in dichloromethane and acetonitrile, which cover the spectral range up to 2000 nm, provide for the first time access to its complete D0 → D1 absorption band, with the peak located at 1250 and 1055 nm, respectively. Good agreement is obtained with results from DFT/TDDFT calculations of the D149 •+ spectrum employing the MPW1K functional. © 2012 the Owner Societies
Ultrafast photoinduced relaxation dynamics of the indoline dye D149 in organic solvents
The relaxation dynamics of the indoline dye D149, a well-known sensitizer for photoelectrochemical solar cells, have been extensively characterized in various organic solvents by combining results from ultrafast pump–supercontinuum probe (PSCP) spectroscopy, transient UV-pump VIS-probe spectroscopy, time-correlated single-photon counting (TCSPC) measurements as well as steady-state absorption and fluorescence. In the steady-state spectra, the position of the absorption maximum shows only a weak solvent dependence, whereas the fluorescence Stokes shift Δ[small nu, Greek, tilde]F correlates with solvent polarity. Photoexcitation at around 480 nm provides access to the S1 state of D149 which exhibits solvation dynamics on characteristic timescales, as monitored by a red-shift of the stimulated emission and spectral development of the excited-state absorption in the transient PSCP spectra. In all cases, the spectral dynamics can be modeled by a global kinetic analysis using a time-dependent S1spectrum. The lifetime τ1 of the S1 state roughly correlates with polarity [acetonitrile (280 ps) < acetone (540 ps) < THF (720 ps) < chloroform (800 ps)], yet in alcohols it is much shorter [methanol (99 ps) < ethanol (178 ps) < acetonitrile (280 ps)], suggesting an appreciable influence of hydrogen bonding on the dynamics. A minor component with a characteristic time constant in the range 19–30 ps, readily observed in the PSCP spectra of D149 in acetonitrile and THF, is likely due to removal of vibrational excess energy from the S1 state by collisions with solvent molecules. Additional weak fluorescence in the range 390–500 nm is observed upon excitation in the S0 → S2 band, which contains short-lived S2 → S0 emission of D149. Transient absorption signals after excitation at 377.5 nm yield an additional time constant in the subpicosecond range, representing the lifetime of the S2 state. S2 excitation also produces photoproducts
Teachers' perceived time pressure, emotional exhaustion and the role of social support from the school principal
Many teachers experience high levels of work-related strain due to time pressure, which over time can lead to various health problems, such as emotional exhaustion. However, there is growing evidence that this could be a reciprocal effect. Moreover, it is known that perceived social support can buffer the negative effects of stress, such as time pressure, on health outcomes. Less is known about buffering effects of received social support. Based on longitudinal data of n = 1071 Swiss primary and secondary school teachers over the course of one school year, the present study examined the reciprocal relationship between teachers’ perceived time pressure and emotional exhaustion and whether received social support from the school principal buffers this relationship. Results of a random intercept cross-lagged panel model show a strong relationship between teachers’ perceived time pressure and emotional exhaustion at the between-person level, but no effects at the within-person level. Further, received social support was directly related to less perceived time pressure and less emotional exhaustion. The results showed neither evidence for reciprocal effects between perceived time pressure and emotional exhaustion nor for a buffering effect of received social support from the school principal. Concluding, present findings indicate that the receipt of social support from the school principal is a central job resource that beneficially relates to teachers’ experience of time pressure and emotional exhaustion
Satisfying the Need for Relatedness Among Teachers: Benefits of Searching for Social Support
The satisfaction of teachers’ need for relatedness is an important pre-condition for teachers’ wellbeing. Receiving social support plays an important role in satisfying the need for relatedness. Following job crafting theory, the present study aims to examine (1) whether searching for social support results in an increase in the satisfaction of the need for relatedness and (2) whether this effect is mediated by an increase of received social support from the school principal and from colleagues. Using longitudinal data (N = 1071) we calculated residualized change scores and applied structural equation modeling to test the hypothesized mediation model. Results confirmed the beneficial effect of searching for social support on the satisfaction of the need for relatedness. This effect included a direct effect and an indirect effect through the receipt of social support from colleagues. The receipt of social support from the school principal was positively related to searching for social support but was unrelated to the satisfaction of the need for relatedness. These findings emphasize the importance that teachers build strong and supportive relationships within the school team, as this helps to satisfy their need for relatedness, which in turn contributes to better wellbeing among teachers
Transformationale Führung und positive Emotionen bei Lehrpersonen – die Rolle der sozialen Unterstützung und der psychologischen Bedürfnisbefriedigung
Positive Emotionen gelten als Schlüsselfaktor zur Steigerung des Wohlbefindens und der Arbeitsleistung. Die vorliegende Studie beleuchtet den Zusammenhang zwischen transformationalem Führungsverhalten der Schulleitung und dem Erleben positiver Emotionen von Lehrpersonen. Es wird untersucht, ob dabei (a) die erhaltene soziale Unterstützung aus dem Team und (b) die Befriedigung der psychologischen Grundbedürfnisse als vermittelnde Mechanismen wirken. Basierend auf Längsschnittdaten von N = 1 217 Lehrpersonen
zeigte sich, dass das individuelle transformationale Führungsverhalten die Bedürfnisse nach Autonomie und sozialer Eingebundenheit befriedigt, was zu einer Erhöhung der positiven Emotionen der Lehrpersonen beiträgt. Für die kollektive transformationale Führung waren die Ergebnisse weniger eindeutig. Sie weisen aber darauf hin, dass diese zu mehr sozialer Unterstützung innerhalb des Teams führt. Dadurch werden die Bedürfnisse nach Autonomie und sozialer Eingebundenheit stärker befriedigt, was wiederum zur Steigerung der positiven Emotionen der Lehrpersonen beiträgt. Schulleitungen können folglich positive Emotionen von Lehrpersonen über zwei verschiedene Wege fördern: Indem sie (1) die psychologischen Grundbedürfnisse der Lehrpersonen befriedigen und (2) die Voraussetzungen für ein unterstützendes Teamklima schaffen
Dual-Focused Transformational Leadership, Teachers’ Satisfaction of the Need for Relatedness, and the Mediating Role of Social Support
Basic psychological need satisfaction is essential for the wellbeing of teachers and motivation at work. Transformational leadership contributes to the development and maintenance of a respectful, constructive atmosphere, a supportive working climate, and has been suggested to be a crucial factor for the satisfaction of the need for relatedness of employees. Transformational leadership is also considered as an ideal leadership style in the school setting, but most studies did not distinguish between individual and team effects of this leadership behavior. In the present study, we applied the dual-focused model of transformational leadership and focused on social processes to address the question of whether individual- and group-focused transformational leadership behavior contribute differently to satisfaction of the need for relatedness of teachers. Based on longitudinal data with three measurement points across one school year of N = 1,217 teachers, results of structural equational models supported the notion of the dual effects of transformational leadership: Individual-focused transformational leadership was directly positively related to change in satisfaction of the need for relatedness of teachers. The relationship between group-focused transformational leadership and change in satisfaction of the need for relatedness was mediated by received social support from team members. These findings emphasize the importance of school leadership behavior of principals for satisfaction of the need for relatedness of teachers. The satisfaction of the need for relatedness is, therefore, not only satisfied through the direct interaction between the school principal and the individual teacher but also through interactions of the school principal with the whole team. Our results confirm that school principals should focus their leadership behavior both on individual need satisfaction of teachers as well as on team development
Time-Resolved Soft X-ray Diffraction Reveals Transient Structural Distortions of Ternary Liquid Crystals
Home-based soft X-ray time-resolved scattering experiments with nanosecond time resolution (10 ns) and nanometer spatial resolution were carried out at a table top soft X-ray plasma source (2.2–5.2 nm). The investigated system was the lyotropic liquid crystal C16E7/paraffin/glycerol/formamide/IR 5. Usually, major changes in physical, chemical, and/or optical properties of the sample occur as a result of structural changes and shrinking morphology. Here, these effects occur as a consequence of the energy absorption in the sample upon optical laser excitation in the IR regime. The liquid crystal shows changes in the structural response within few hundred nanoseconds showing a time decay of 182 ns. A decrease of the Bragg peak diffracted intensity of 30% and a coherent macroscopic movement of the Bragg reflection are found as a response to the optical pump. The Bragg reflection movement is established to be isotropic and diffusion controlled (1 μs). Structural processes are analyzed in the Patterson analysis framework of the time-varying diffraction peaks revealing that the inter-lamellar distance increases by 2.7 Å resulting in an elongation of the coherently expanding lamella crystallite. The present studies emphasize the possibility of applying TR-SXRD techniques for studying the mechanical dynamics of nanosystems
System level ESD protection
This book addresses key aspects of analog integrated circuits and systems design related to system level electrostatic discharge (ESD) protection. It is an invaluable reference for anyone developing systems-on-chip (SoC) and systems-on-package (SoP), integrated with system-level ESD protection. The book focuses on both the design of semiconductor integrated circuit (IC) components with embedded, on-chip system level protection and IC-system co-design. The readers will be enabled to bring the system level ESD protection solutions to the level of integrated circuits, thereby reducing or completely eliminating the need for additional, discrete components on the printed circuit board (PCB) and meeting system-level ESD requirements. The authors take a systematic approach, based on IC-system ESD protection co-design. A detailed description of the available IC-level ESD testing methods is provided, together with a discussion of the correlation between IC-level and system-level ESD testing methods. The IC-level ESD protection design is demonstrated with representative case studies which are analyzed with various numerical simulations and ESD testing. The overall methodology for IC-system ESD co-design is presented as a step-by-step procedure that involves both ESD testing and numerical simulations.  • Provides a systematic approach for on-chip ESD protection design for system-level IC pins; • Describes a system-level co-design methodology, which uses external system level ESD protection components, together with on-chip ESD protection structure; • Includes a comprehensive description of wafer- level and component-level test methodologies and numerical simulations