bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antimicrobial Resistance and Social Inequalities in Health: Considerations of Justice
Authors: Reid Lynette 
Published: October 2020

AbstractWithin-country social inequalities in health have widened while global health inequalities have (with some exceptions) narrowed since the Second World War. On commonly accepted prioritarian and sufficientist views of justice and health, these two trends together would be acceptable: the wealthiest of the wealthy are pulling ahead, but the worst off are catching up and more are achieving sufficiency. Such commitments to priority or sufficiency are compatible with a common “development” narrative about economic and social changes that accompany changes (“transitions”) in population health. I set out a very simple version of health egalitarianism (without commitment to any particular current theory of justice) and focus on two common objections to egalitarianism. Priority and sufficiency both address the levelling down and formalism objections, but these objections are distinct: giving content to equality (I argue here) places in question the claimed normative superiority of priority and sufficiency. Using examples of the role of antimicrobials in both these trends – and the future role of AMR – I clarify (first) the multiple forms and dimensions of justice at play in health, and (second) the different mechanisms at work in generating the two current patterns (seen in life course narratives and narratives of political economy). The “accelerated transition” that narrowed global health inequalities is fed by anti-microbials (among other technology transfers). It did not accelerate but replaced the causal processes by which current HICs achieved the transition (growing and shared economic prosperity and widening political franchise). The impact of AMR on widening social inequalities in health in HICs will be complex: inequality has been fed in part by tertiary care enabled by antimicrobials; AMR might erode the solidarity underlying universal health systems as the well-off seek to maintain current expectations of curative and rehabilitative surgery and chemotherapy while AMR mounts. In light of both speculations about the impact of AMR on social and global health inequalities, I close with practical and with theoretical reflection. I briefly indicate the practical importance of understanding AMR from the perspective of health justice for policy response. Then, from a broader perspective, I argue that the content by which I meet the formalism objection demonstrates that the two trends (broadening within-country inequality and narrowing global inequality) are selective and biased samples of a centuries-long pattern of widening social inequalities in health. We are not in the midst of a process of “catching up”. In light of the long-term pattern described here, is the pursuit of sufficiency or priority morally superior to the pursuit of equality as a response to concrete suffering – or do they rationalize a process more objectively described as the best-off continuing to take the largest share of one of the most important benefits of economic development?
Solidarity and Antimicrobial Resistance
Authors: Holm Søren , Ploug Thomas 
Published: October 2020

AbstractThe concept of solidarity has received increasing attention in discussions about public health interventions, both as a possible justification for such interventions and as a possible motivating factors for individual action. This chapter provides an analysis of whether thinking through a lens of solidarity is likely to be helpful in devising strategies and policies to combat antimicrobial resistance. It first provides a critical overview of recent accounts of solidarity and argues that solidarity must be understood as a group based concept. It then applies this conception of solidarity to individual use of antibiotics through a case study of the antibiotic treatment of moderate and severe acne where it is argued that solidarity based thinking is valuable within a context of shared decision-making. Issues of policy making are then discussed and it is argued that basing a policy on solidarity on the one hand constrains the methods chosen to pursue public health goals, but that on the other hand solidarity may provide a strong and durable motivation to comply with such a policy. The limits of solidarity are explored in the final section and it is concluded that 1) the concept of solidarity does have an important role to play in thinking about public health, 2) considerations of solidarity can help us shape the goals and methods of public health policies in the area of antibiotics, and 3) that it is likely that solidarity may also be helpful in thinking through other contentious issues in public health.
Global Health Governance and Antimicrobial Resistance
Authors: Bennett Belinda , Iredell Jon 
Published: October 2020

AbstractThis chapter analyses the challenges and the adequacy of existing frameworks to provide a strong foundation to support global responses to antimicrobial resistance. Calls for global responses are indicative of a growing global commitment to seeking practical means of tackling the growing problem of antimicrobial resistance. While antimicrobial resistance is often conceptualised as an emergency, the application of the International Health Regulations, designed to govern responses to public health emergencies of international concern, remains unclear. Furthermore, there may be challenges for countries in developing and resourcing national approaches to address antimicrobial resistance. Clarity and agreement around definitions of key concepts related to antimicrobial resistance will also be essential to antibiotic stewardship and development of policy in this area. Finally, improvements to health systems as a result of the Sustainable Development Goals may help to support improvements in public health and may play a role in global strategies to address antimicrobial resistance.
Providing Universal Access While Avoiding Antiretroviral Resistance: Ethical Tensions in HIV Treatment
Authors: Haire Bridget 
Published: October 2020

AbstractThe provision of effective antiretroviral therapy is an ethical imperative, and global access to antiretroviral drugs is an important aspect of this. The other less recognised aspect of effective HIV management is in ensuring that HIV does not become resistant to the drugs used in treatment (and increasingly also in prevention), as multi-drug resistant HIV poses a major threat to the sustainability of current responses to HIV control. In resource-constrained environments, the rapid scale up of access to life-saving anti-HIV treatment was achieved using a public health approach that standardised antiretroviral regimens, minimised laboratory monitoring, and devolved responsibilities from clinicians where necessary. In recent years demand for antiretroviral treatment has increased due to new understandings of the clinical importance of early treatment, but global investment has declined. Exponential growth of the population using antiretrovirals without careful monitoring increases the risk of significant antiretroviral drug resistance. In this chapter, I consider the example of single-drug interventions to prevent parent-to-child HIV transmission, and how the implementation of that strategy increased health risks for mothers. I argue that while global antiretroviral scale up must continue, laboratory monitoring at individual and national levels needs to improve to maintain treatment effectiveness, and protocols for moving people from failing regimens need to be strengthened.
Hospital Infection Prevention and Control (IPC) and Antimicrobial Stewardship (AMS): Dual Strategies to Reduce Antibiotic Resistance (ABR) in Hospitals
Authors: Gilbert Gwendolyn L. , Kerridge Ian 
Published: October 2020

AbstractIn this chapter we review the development of hospital infection prevention and control (IPC) since the nineteenth century and its increasingly important role in reducing the spread of antibiotic resistance (ABR). Excessive rates of hospital-acquired infection (HAI) fell dramatically, towards the end of the nineteenth century, because of improved hygiene and surgical antisepsis, but treatment remained rudimentary until effective antibiotics became widely available in the mid-twentieth century. While antibiotics had profound clinical benefits, their widespread appropriate and inappropriate use in humans and animals inevitably led to the emergence of antibiotic resistance (ABR). Within 50 years, this could no longer be offset by a reliable supply of new drugs, which slowed to a trickle in the 1980s. In hospitals, particularly, high rates of (often unnecessary) antibiotic use and ABR are exacerbated by person-to-person transmission of multi-drug resistant organisms (MDRO), which have, so far, largely resisted the introduction of antimicrobial stewardship (AMS) programs and repeated campaigns to improve infection prevention and control (IPC). Despite clear evidence of efficacy in research settings, both AMS and IPC programs are often ineffective, in practice, because of, inter alia, insufficient resourcing, poor implementation, lack of ongoing evaluation and failure to consult frontline staff. In this chapter we review reasons for the relatively low priority given to preventive programs despite the ethical obligation of healthcare organisations to protect current and future patients from preventable harm. The imminent threat of untreatable infections may provide an impetus for a shared organisational and professional commitment to promoting the cultural and behavioural changes needed to successfully reduce the burdens of ABR and drug-resistant HAIs.
The Virtuous Physician and Antimicrobial Prescribing Policy and Practice
Authors: Oakley Justin 
Published: October 2020

AbstractIn this chapter, I outline some key patient-centred medical virtues and several community-centred medical virtues, and I consider what sorts of antimicrobial prescribing decisions such virtues would lead physicians to make. I argue that practically-intelligent virtuous physicians should also have an awareness of the sorts of cognitive biases that are especially likely to distort their antimicrobial prescribing decisions, and I urge physicians to develop ways of avoiding or counteracting such biases. Further, I argue that effectively addressing the impact of these biases and other countervailing factors that inhibit virtuous prescribing practices is the responsibility not only of individual physicians, but also of institutions and regulators. I outline some strategies that individual physicians, institutions, and healthcare policymakers could develop to help physicians hit the targets of those patient-centred and community-centred medical virtues, and to thereby play their part in redressing the problems of antimicrobial resistance.
Numerical Analysis of the Turbulent Wake for a Generic Space Launcher with a Dual-Bell Nozzle
Authors: Loosen Simon , Meinke Matthias , Schröder Wolfgang 
Published: October 2020

Abstract
The turbulent wake of an axisymmetric generic space launcher equipped with a dual-bell nozzle is simulated at transonic ($$Ma_\infty = 0.8$$ and $$Re_D = 4.3\cdot 10^5$$) and supersonic ($$Ma_\infty = 3$$ and $$Re_D = 1.2\cdot 10^6$$) freestream conditions, to investigate the influence of the dual-bell nozzle jet onto the wake flow and vice versa. In addition, flow control by means of four in circumferential direction equally distributed jets injecting air encountering the backflow in the recirculation region is utilized to determine if the coherence of the wake and consequently, the buffet loads can be reduced by flow control. The simulations are performed using a zonal RANS/LES approach. The time-resolved flow field data are analyzed by classical spectral analysis, two-point correlation analysis, and dynamic mode decomposition (DMD). At supersonic freestream conditions, the nozzle counter pressure is reduced by the expansion of the outer flow around the nozzle lip leading to a decreased transition nozzle pressure ratio. In the transonic configuration a spatio-temporal mode with an eigenvalue matching the characteristic buffet frequency of $$Sr_D=0.2$$ is extracted by the spectral and DMD analysis. The spatial shape of the detected mode describes an antisymmetric wave-like undulating motion of the shear layer inducing the low frequency dynamic buffet loads. By flow control this antisymmetric coherent motion is weakened leading to a reduction of the buffet loads on the nozzle fairing.
Numerical Investigation of Injection, Mixing and Combustion in Rocket Engines Under High-Pressure Conditions
Authors: Traxinger Christoph , Zips Julian , Stemmer Christian , Pfitzner Michael 
Published: October 2020

Abstract
The design and development of future rocket engines severely relies on accurate, efficient and robust numerical tools. Large-Eddy Simulation in combination with high-fidelity thermodynamics and combustion models is a promising candidate for the accurate prediction of the flow field and the investigation and understanding of the on-going processes during mixing and combustion. In the present work, a numerical framework is presented capable of predicting real-gas behavior and nonadiabatic combustion under conditions typically encountered in liquid rocket engines. Results of Large-Eddy Simulations are compared to experimental investigations. Overall, a good agreement is found making the introduced numerical tool suitable for the high-fidelity investigation of high-pressure mixing and combustion.
Experimental Investigation of Injection-Coupled High-Frequency Combustion Instabilities
Authors: Armbruster Wolfgang , Hardi Justin S. , Oschwald Michael 
Published: October 2020

Abstract
Self-excited high-frequency combustion instabilities were investigated in a 42-injector cryogenic rocket combustor under representative conditions. In previous research it was found that the instabilities are connected to acoustic resonance of the shear-coaxial injectors. In order to gain a better understanding of the flame dynamics during instabilities, an optical access window was realised in the research combustor. This allowed 2D visualisation of supercritical flame response to acoustics under conditions similar to those found in European launcher engines. Through the window, high-speed imaging of the flame was conducted. Dynamic Mode Decomposition was applied to analyse the flame dynamics at specific frequencies, and was able to isolate the flame response to injector or combustion chamber acoustic modes. The flame response at the eigenfrequencies of the oxygen injectors showed symmetric and longitudinal wave-like structures on the dense oxygen core. With the gained understanding of the BKD coupling mechanism it was possible to derive LOX injector geometry changes in order to reduce the risks of injection-coupled instabilities for future cryogenic rocket engines.
Pseudo-transient 3D Conjugate Heat Transfer Simulation and Lifetime Prediction of a Rocket Combustion Chamber
Authors: Barfusz Oliver , Hötte Felix , Reese Stefanie , Haupt Matthias 
Published: October 2020

AbstractRocket engine nozzle structures typically fail after a few engine cycles due to the extreme thermomechanical loading near the nozzle throat. In order to obtain an accurate lifetime prediction and to increase the lifetime, a detailed understanding of the thermomechanical behavior and the acting loads is indispensable. The first part is devoted to a thermally coupled simulation (conjugate heat transfer) of a fatigue experiment. The simulation contains a thermal FEM model of the fatigue specimen structure, RANS simulations of nine cooling channel flows and a Flamelet-based RANS simulation of the hot gas flow. A pseudo-transient, implicit Dirichlet–Neumann scheme is utilized for the partitioned coupling. A comparison with the experiment shows a good agreement between the nodal temperatures and their corresponding thermocouple measurements. The second part consists of the lifetime prediction of the fatigue experiment utilizing a sequentially coupled thermomechanical analysis scheme. First, a transient thermal analysis is carried out to obtain the temperature field within the fatigue specimen. Afterwards, the computed temperature serves as input for a series of quasi-static mechanical analyses, in which a viscoplastic damage model is utilized. The evolution and progression of the damage variable within the regions of interest are thoroughly discussed. A comparison between simulation and experiment shows that the results are in good agreement. The crucial failure mode (doghouse effect) is captured very well.
Lifetime Experiments of Regeneratively Cooled Rocket Combustion Chambers and PIV Measurements in a High Aspect Ratio Cooling Duct
Authors: Hötte Felix , Günther Oliver , von Sethe Christoph , Haupt Matthias , Scholz Peter , Rohdenburg Michael 
Published: October 2020

AbstractThis paper aims at experimental investigations of the life limiting mechanisms of regeneratively cooled rocket combustion chambers, especially the so called doghouse effect. In this paper the set up of a cyclic thermo-mechanical fatigue experiment and its results are shown. This experiment has an actively cooled fatigue specimen that is mounted downstream of a subscale GOX-GCH$$_{\text {4}}$$combustion chamber with rectangular cross section. The specimen is loaded cyclically and inspected after each cycle. The effects of roughness, the use of thermal barrier coatings, the length of the hot gas phase, the oxygen/fuel ratio and the hot gas pressure are shown. In a second experiment the flow in a generic high aspect ratio cooling duct is measured with the Particle Image Velocimetry (PIV) to characterize the basic flow. The main focus of the analysis is on the different recording and processing parameters of the PIV method. Based on this analysis a laser pulse interval and the window size for auto correlation is chosen. Also the repeatability of the measurements is demonstrated. These results are the starting point for future measurements on the roughness effect on heat transfer and pressure loss in a high aspect ratio cooling duct.
Mechanical Integrity of Thermal Barrier Coatings: Coating Development and Micromechanics
Authors: Fiedler Torben , Rösler Joachim , Bäker Martin , Hötte Felix , von Sethe Christoph , Daub Dennis , Haupt Matthias , Haidn Oskar J. , Esser Burkard , Gülhan Ali 
Published: October 2020

Abstract
To protect the copper liners of liquid-fuel rocket combustion chambers, a thermal barrier coating can be applied. Previously, a new metallic coating system was developed, consisting of a NiCuCrAl bond-coat and a Rene 80 top-coat, applied with high velocity oxyfuel spray (HVOF). The coatings are tested in laser cycling experiments to develop a detailed failure model, and critical loads for coating failure were defined. In this work, a coating system is designed for a generic engine to demonstrate the benefits of TBCs in rocket engines, and the mechanical loads and possible coating failure are analysed. Finally, the coatings are tested in a hypersonic wind tunnel with surface temperatures of 1350 K and above, where no coating failure was observed. Furthermore, cyclic experiments with a subscale combustion chamber were carried out. With a diffusion heat treatment, no large-scale coating delamination was observed, but the coating cracked vertically due to large cooling-induced stresses. These cracks are inevitable in rocket engines due to the very large thermal-strain differences between hot coating and cooled substrate. It is supposed that the cracks can be tolerated in rocket-engine application.
A Coupled Two-Domain Approach for Transpiration Cooling
Authors: König Valentina , Rom Michael , Müller Siegfried 
Published: October 2020

Abstract
Transpiration cooling is an innovative cooling concept where a coolant is injected through a porous ceramic matrix composite (CMC) material into a hot gas flow. This setting is modeled by a two-domain approach coupling two models for the hot gas domain and the porous medium to each other by coupling conditions imposed at the interface. For this purpose, appropriate coupling conditions, in particular accounting for local mass injection, are developed. To verify the feasibility of the two-domain approach numerical simulations in 3D are performed for two different application scenarios: a subsonic thrust chamber and a supersonic nozzle.
Experiments on Aerothermal Supersonic Fluid-Structure Interaction
Authors: Daub Dennis , Willems Sebastian , Esser Burkard , Gülhan Ali 
Published: October 2020

AbstractMastering aerothermal fluid-structure interaction (FSI) is crucial for the efficient and reliable design of future (reusable) launch vehicles. However, capabilities in this area are still quite limited. To address this issue, a multidisciplinary experimental and numerical study of such problems was conducted within SFB TRR 40. Our work during the last funding period was focused on studying the effects of moderate and high thermal loads. This paper provides an overview of our experiments on FSI including structural dynamics and thermal effects for configurations in two different flow regimes. The first setup was designed to study the combined effects of thermal and pressure loads. We investigated a range of conditions including shock-wave/boundary-layer interaction (SWBLI) with various incident shock angles leading to, in some cases, large flow separation with high amplitude temperature dependent panel oscillations. The respective aerothermal loads were studied in detail using a rigid reference panel. The second setup allowed us to study the effects of severe heating leading to plastic deformation of the structure. We obtained severe localized heating resulting in partly plastic deformations of more than 12 times the panel thickness. Furthermore, the effects of repeated load cycles were studied.
Rocket Combustion Chamber Simulations Using High-Order Methods
Authors: Seitz Timo , Lechtenberg Ansgar , Gerlinger Peter 
Published: October 2020

Abstract
High-order spatial discretizations significantly improve the accuracy of flow simulations. In this work, a multi-dimensional limiting process with low diffusion (MLP$$^\text {ld}$$) and up to fifth order accuracy is employed. The advantage of MLP is that all surrounding volumes of a specific volume may be used to obtain cell interface values. This prevents oscillations at oblique discontinuities and improves convergence. This numerical scheme is utilized to investigate three different rocket combustors, namely a seven injector methane/oxygen combustion chamber, the widely simulated PennState preburner combustor and a single injector chamber called BKC, where pressure oscillations are important.
Definition and Evaluation of Advanced Rocket Thrust Chamber Demonstrator Concepts
Authors: Eiringhaus Daniel , Riedmann Hendrik , Knab Oliver 
Published: October 2020

Abstract
Since the beginning of the German collaborative research center SFB-TRR 40 in 2008 ArianeGroup has been involved as industrial partner and supported the research activities with its expertise. For the final funding period ArianeGroup actively contributes to the SFB-TRR 40 with the self-financed project K4. Within project K4 virtual thrust chamber demonstrators have been defined that allow the application of the attained knowledge of the entire collaborative research center to state-of-the-art numerical benchmark cases. Furthermore, ArianeGroup uses these testcases to continue the development of its in-house spray combustion and performance analysis tool Rocflam3. Unique within the collaborative research center fully three-dimensional conjugate heat transfer computations have been performed for a full-scale 100 kN upper stage thrust chamber. The strong three-dimensionality of the temperature field in the structure resulting from injection element and cooling channel configuration is displayed.