Reflection silencers are installed in the exhaust system of stationary combustion engines to attenuate low-frequency noise by means of destructive interference. The acoustic properties of mufflers are experimentally determined by the standard two-load method, which only considers measurements without mean flow. In real engine operation, however, exhaust mass flow is always present. Measurements are significantly more complex and expensive if fluid flow is taken into account, which is why the available data is limited. Thus, the impact of mean flow on the attenuation of silencers is not clearly known yet. This work contributes to the state of the art by quantifying the influence of the Mach number on the transmission loss of double-tuned straight-through mufflers based on reproducible, noise corrected measurement results that include uncertainties. A frequency range between 20 Hz and 891 Hz is investigated at eleven different Mach numbers between 0 and 0.1 under ambient conditions. It is found that resonance peaks diminish with increasing Mach number, while other frequencies remain unaffected by mean flow. These findings can be transferred to operating conditions of stationary combustion engines and other exhaust systems. The experimental data will serve as a basis for the validation of analytical and numerical models in subsequent work.

In this work, the Theory of Porous Media (TPM) is employed to model percutaneous vertebroplasty, a medical procedure in which acrylic cement is injected into cancellous vertebral bone. Previously, isothermal macroscale models have been derived to describe this material injection and the arising mechanical interactions. However, the temperature of the injected cement is typically below the human body temperature, necessitating the extension of these existing models to the non-isothermal case. Following the modelling principles of the TPM and considering local thermal non-equilibrium conditions, our model introduces three energy balances as well as constitutive relations for thermal conduction and heat transfer. If restricted to local thermal equilibrium conditions, our model equations are in agreement with other TPM-based models. We observe that our model elicits physically reasonable behaviour in numerical simulations that employ parameter values and initial and boundary conditions relevant for our application. We claim our model to be thermodynamically consistent despite the employment of the Coleman and Noll procedure.

Empirische Rechtswissenschaft im Fokus: Dieses Buch bietet einen fundierten Überblick über Stand und Perspektiven interdisziplinärer Rechtswissenschaften. Von Verfassungs-, Europa-, Kartell- und Strafrecht über richterliches Entscheidungsverhalten bis hin zu Fragen von Politikberatung, Arbeitsmärkten und Gemeinschaftsgütern entfalten die Beiträge ein breites thematisches Spektrum. Zugleich zeigen sie, wie Verhaltenswissenschaften, datengetriebene Methoden und Künstliche Intelligenz unser Verständnis des Rechts vertiefen und verändern. Sie zeichnen dabei auch das Wirken von Christoph Engel, Direktor am Max-Planck-Institut zur Erforschung von Gemeinschaftsgütern, nach. 

While forests are known to increase turbulence and fatigue loads on wind turbines, the impact of smaller-scale vegetation such as tree rows has received limited attention. This study investigates speed-up effects caused by a tree row and their influence on wind turbine power and blade loads using Detached Eddy Simulation (DES) and OpenFAST. A realistically modeled tree row at the Risø campus is considered, including seasonal variations in leaf area index (LAI). The simulations reveal a speed-up region above the canopy, leading to a relative power increase of approximately 6% for the high-LAI case and about half that value for the low-LAI case. Aeroelastic simulations with the NREL 5 MW wind turbine confirm the power increase and show a rise in flapwise blade root bending loads. Second-order statistics within the rotor plane remain largely unchanged, indicating that the load increase is driven by mean flow acceleration rather than turbulence. These results demonstrate that tree rows can increase power and highlight the influence of local vegetation in wind turbine siting.

This paper experimentally examines how different greenfluencer message types (emotional, informational, social, and neutral) on Instagram affect purchase intention and attitudes toward sustainable fashion, with a particular focus on non-sustainable consumers. In an online experiment, 202 participants were randomly assigned to one of four fictitious Instagram posts and completed pre- and post-measures of attitudes and purchase intention. The results show that none of the message types improved purchase intention or attitudes; instead, most effects were negative. However, attitudes remained positively associated with purchase intention. The findings suggest that greenfluencer communication does not automatically promote sustainable consumer responses and is not more effective among non-sustainable consumers.

Background:
While border screening measures were widely adopted by countries during the COVID-19 pandemic, a lack of consensus on the utility of border screening created a gap in best practice for its implementation. As such, countries adopted a diversity of approaches, providing an opportunity to evaluate the configuration and evolution of border screening systems. The
article addresses three questions: (i) how did countries configure their border screeningsystems for COVID-19? (ii) In what contexts did countries rely on public or private providers of these services? (iii) what do policies and narratives reveal about the perceived role of border screening in global public health? The article contributes to long-standing debates over the
private sector’s role in public health and the perceived value of border screening measures.

Methods:
This article presents results from an international comparative study based on tracking the organisation of border screening in eight countries. Secondary data was collected between  July 2021 – June 2022 from official government websites and policy publications, private sector sources where relevant, and trusted media sources in each study country. The
countries included are Australia, Canada, Germany, Ireland, South Africa, South Korea, Spain, and the United Kingdom.

Results:
All study countries used private provision for pre-departure diagnostic testing for international travellers. In contrast, screening of arriving travellers was more diverse. Countries that opted for private sector post-arrival screening saw governance challenges around accreditation and monitoring of providers, while public service provision saw challenges in capacity and high
resource costs. Travel was often framed as a ‘luxury,’ allowing states to shift responsibility for obtaining tests onto individuals; especially in the context of individuals travelling from low income to high income countries.

Conclusions:
The different approaches countries followed for screening of departing and incoming travellers suggests wealthy countries were more oriented towards defending their populations against disease importation, rather protecting the international community from disease exportation. These findings provide an opportunity to reflect on the purpose and
implementation of border screening. We emphasise a need for further discussion on the efficacy of border screening from both perspectives, given the tendency for countries to rely on these measures