Measuring the Effect of Moist Droplet-laden Flow on Transonic Compressor Cascade Performance

International audienceThis study provides insight on the influence of air humidity on droplet laden flow as it occurs during inlet fogging and in steam turbines. D-LDA is used to gather air-only data at three different humidities to rate humidity-depended cascade losses such as shock and profile boundary layer losses. Likewise, change in aerodynamics is explained using a combination of isentropic and Rayleigh flow. Then, water droplets are added to the flow field and data is collected using D-PDA. Again losses are evaluated. Regarding the droplet-free flow, effects and relations found in literature could be confirmed for the presented cascade flow. However, the results further indicate that for droplet-laden flows favourable humidity effects are decreased and may be neglected since the major loss arises from the increased boundary layer thickness

Environmental management as situated practice

We propose an analysis of environmental management (EM) as work and as practical activity. This approach enables empirical studies of the diverse ways in which professionals, scientists, NGO staffers, and activists achieve the partial manageability of specific “environments”. In this introduction, we sketch the debates in Human Geography, Management Studies, Science and Technology Studies to which this special issue contributes. We identify the limits of understanding EM though the framework of ecological modernization, and show how political ecology and work- place studies provide important departures towards a more critical approach. Developing these further, into a cosmopolitical direction, we propose studying EM as sets of socially and materially situated practices. This enables a shift away from established approaches which treat EM either as a toolbox whose efficiency has to be assessed, or as simply the implementation of dominant projects and the materialisation of hegemonic discourse. Such a shift renders EM as always messy practices of engagement, critique and improvisation. We conclude that studying the distributed and situated managing agencies, actors and their practices allows to imagine new forms of critical interventions

Monte Carlo-simulering av tillverkningskostnaden

DPM is a manufacturing company within the metal cutting industry. A number of years ago there emerged a desire to make statistical calculations for its production. Until today, the company has not done any post-calculations, which means that they have based their cost calculations and sales prices on precalculated costs. The absence of post-calculations leads to lack of cost-consciousness that is required to optimize the product portfolio and sales. Monte Carlo simulation has become a common and useful tool to make statistical studies of processes. The method has been little used in the production economic area until now and this report’s meaning is to fill in the missing gaps and take it to a higher level. The purpose of the Monte Carlo simulation is to obtain the distribution functions of the cost of production and thereby determine the probability to a certain cost or profit. The study shows that Monte Carlo simulation works well to investigate the production economics in a manufacturing company. From the results of the report it can be concluded that some details generates profits while others aren’t. Moreover, it can be seen that great variances occurs in the production, which leads to a higher cost consciousness when recognized. Monte Carlo simulation of the manufacturing cost can be very useful for companies to implement. The methodology requires a deeper knowledge of statistics. This, combined with the large amount of data collection can in many cases lead to absence of simulation. The conclusion is therefore that it would be best if manufacturers of information systems could adopt this method and implement it in their systems. The work has received good response from DPM when it comes to follow-up on details in production. From having abstained completely from the post-calculations and go all the way to follow the statistical methodology of work, considering variations is a major and challenging step. If DPM can continue making postcalculations this will hopefully make the improvement that leads to a more optimized product portfolio with less products that contribute with losses

Ultrafast Photo-Induced Charge Transfer Unveiled by Two-Dimensional Electronic Spectroscopy

The interaction of exciton and charge transfer (CT) states plays a central role in photo-induced CT processes in chemistry, biology and physics. In this work, we use a combination of two-dimensional electronic spectroscopy (2D-ES), pump-probe measurements and quantum chemistry to investigate the ultrafast CT dynamics in a lutetium bisphthalocyanine dimer in different oxidation states. It is found that in the anionic form, the combination of strong CT-exciton interaction and electronic asymmetry induced by a counter-ion enables CT between the two macrocycles of the complex on a 30 fs timescale. Following optical excitation, a chain of electron and hole transfer steps gives rise to characteristic cross-peak dynamics in the electronic 2D spectra, and we monitor how the excited state charge density ultimately localizes on the macrocycle closest to the counter-ion within 100 fs. A comparison with the dynamics in the radical species further elucidates how CT states modulate the electronic structure and tune fs-reaction dynamics. Our experiments demonstrate the unique capability of 2D-ES in combination with other methods to decipher ultrafast CT dynamics.Comment: 14 pages, 11 figures, and Supporting informatio

Co-occurrence, stability and manifestation of child and adolescent mental health problems: a latent transition analysis

Background Complex constellations of socio-emotional and behavioural problems (i.e., mental health problems) in childhood and adolescence are common and heighten the risk for subsequent personality, anxiety and mood disorders in adulthood. Aims of this study included the examination of patterns of mental health problems (e.g., externalizing-internalizing co-occurrence) and their transitions to reported mental disorders by using a longitudinal person-centered approach (latent class and latent transition analysis). Methods The sample consisted of 1255 children and adolescents (51.7% female, mean age = 12.3 years, age range 8–26 years) from three time points of the comprehensive mental health and wellbeing BELLA study. Children and their parents completed the German SDQ (Strength and Difficulties Questionnaire, Goodman, 1997) and reported on diagnoses of ADHD, depression, and anxiety. Results Latent class analysis identified a normative class, an emotional problem class, and a multiple problem class. According to latent transition analysis, the majority of the sample (91.6%) did not change latent class membership over time; 14.7% of individuals showed a persistent pattern of mental health problems. Diagnoses of mental disorders were more likely to be reported by individuals in the emotional problem or multiple problem class. Conclusions Results highlight the need for early prevention of mental health problems to avoid accumulation and manifestation in the transition to adolescence and young adulthood

Switching the Switch: Ligand Induced Disulfide Formation in HDAC8

Human histone deacetylase 8 is a well‐recognized target for T‐cell lymphoma and particularly childhood neuroblastoma. PD‐404,182 was shown to be a selective covalent inhibitor of HDAC8 that forms mixed disulfides with several cysteine residues and is also able to transform thiol groups to thiocyanates. Moreover, HDAC8 was shown to be regulated by a redox switch based on the reversible formation of a disulfide bond between cysteines Cys$_{102}$ and Cys$_{153}$. This study on the distinct effects of PD‐404,182 on HDAC8 reveals that this compound induces the dose‐dependent formation of intramolecular disulfide bridges. Therefore, the inhibition mechanism of HDAC8 by PD‐404,182 involves both, covalent modification of thiols as well as ligand mediated disulfide formation. Moreover, this study provides a deep molecular insight into the regulation mechanism of HDAC8 involving several cysteines with graduated capability to form reversible disulfide bridges

A neutron trigger detector for pulsed neutron sources

A variety of experiments investigating properties of neutrons can be performed at pulsed source facilities like the research reactor TRIGA Mainz. A typical problem faced by these experiments is the non-availibility of a reliable facility-provided trigger signal in coincidence with the neutron production. Here we present the design and implementation of a neutron pulse detector that provides a coincident trigger signal for experimental timing with a relative precision of 4.5 ms.Comment: 16 pages, 10 figure

Leitfaden zum wissenschaftlichen Arbeiten im Fach Kunstgeschichte

Dieser Leitfaden dient als erste Orientierung für die eigenständige Erstellung wissenschaftlicher Vorträge und Erarbeitung wissenschaftlicher Texte. Dabei gibt es verschiedene Möglichkeiten, diesen Leitfaden zu nutzen: Sie können ihn – wie ein Buch – als eine erste Einführung in die wissenschaftliche Auseinandersetzung mit kunsthistorischen Fragen verwenden oder aber anlassbezogen einzelne Kapitel herausgreifen und wiederlesen, etwa immer dann, wenn Sie an der Ausarbeitung eines Referats oder einer schriftlichen Hausarbeit sitzen. Für beide Verwendungsarten ist der Text ausgelegt. Wir hoffen, Ihnen damit einen Kompass für Ihre Erkundungen im Feld der Kunstgeschichte an die Hand geben zu können: Der Wege gibt es viele – nach und nach werden Sie unterschiedliche Herangehensweisen und Themenfelder kennenlernen

Leitfaden zum wissenschaftlichen Arbeiten im Fach Kunstgeschichte

Dieser Leitfaden dient als erste Orientierung für die eigenständige Erstellung wissenschaftlicher Vorträge und Erarbeitung wissenschaftlicher Texte. Dabei gibt es verschiedene Möglichkeiten, diesen Leitfaden zu nutzen: Sie können ihn – wie ein Buch – als eine erste Einführung in die wissenschaftliche Auseinandersetzung mit kunsthistorischen Fragen verwenden oder aber anlassbezogen einzelne Kapitel herausgreifen und wiederlesen, etwa immer dann, wenn Sie an der Ausarbeitung eines Referats oder einer schriftlichen Hausarbeit sitzen. Für beide Verwendungsarten ist der Text ausgelegt. Wir hoffen, Ihnen damit einen Kompass für Ihre Erkundungen im Feld der Kunstgeschichte an die Hand geben zu können: Der Wege gibt es viele – nach und nach werden Sie unterschiedliche Herangehensweisen und Themenfelder kennenlernen