RWTH Aachen University

This paper investigates evaluation methods of thermal transient measurements to obtain the internal thermal structure of semiconductor devices. First, the study uncovers the limitations of a widely accepted standard method that uses frequency-domain deconvolution. An important finding is that the sideband of the time constant spectrum by the standard method has no physical meaning despite it has been interpreted as a continuous spectrum for a long time. Second, by understanding the limitations of the existing method, the paper proposes an alternative method that remodels the frequency-domain deconvolution as a regularized least squares problem in the time domain. With the benchmark of the true values of several thermal networks based on simulation, the proposed sparsity-promoting method demonstrates several advantages, including a better ability to identify adjacent parameters in the time-constant spectrum and the obtained structure function reducing relative error by an order of magnitude. The influence of varying noise levels has also been evaluated. Finally, a proof-of-concept experiment using a commercial power semiconductor device validates its effectiveness

Establishing an economic and sustained Fenton oxidation system to enhance sludge dewaterability and carbamazepine (CBZ) removal rate is a crucial path to simultaneously achieve sludge reduction and harmless. Leveraging the principles akin to "tea making", we harnessed tea waste to continually release tea polyphenols (TP), thus effectively maintaining high level of oxidation efficiency through the sustained Fenton reaction. The results illustrated that the incorporation of tea waste yielded more favorable outcomes in terms of water content reduction and CBZ removal compared to direct TP addition within the Fe(III)/hydrogen peroxide (H2O2) system. Concomitantly, this process mainly generated hydroxyl radical (•OH) via three oxidation pathways, effectively altering the properties of extracellular polymeric substances (EPS) and promoting the degradation of CBZ from the sludge mixture. The interval addition of Fe(III) and H2O2 heightened extracellular oxidation efficacy, promoting the desorption and removal of CBZ. The degradation of EPS prompted the transformation of bound water to free water, while the formation of larger channels drove the discharge of water. This work achieved the concept of treating waste with waste through using tea waste to treat sludge, meanwhile, can provide ideas for subsequent sludge harmless disposal.

Each year, an enormous number of tires approach the end of their useful lives, posing threats to human health and the environment. On the other hand, cement is frequently used to treat soils in geotechnical applications, while its production causes a significant environmental impact. Thus, this study provides a disposal alternative by investigating the influence of tire rubber fiber (TRF) as a partial replacement of cement in artificially cemented soils. Unconfined compressive strength (qu) and ultrasonic pulse velocity (UPV) were measured on the various mixtures to assess strength, stiffness, and ductility index. Statistical analysis and regression models were conducted, and a novel approach to estimate rubberized-cemented-clay was proposed to determine Go, qu, and E from a single nondestructive test. Moreover, SEM was performed to observe the interaction of the TRF and cement with the clay on a microscopic scale. The results showed that the 2.5% TRF content improves rubberized cemented clay’s strength, stiffness, and ductility index by around 12–15%. Furthermore, up to 10% of the TRF blends achieved the minimum requirements for rammed earth, base, and sub-base treated soils. However, 20% of TRF reduces Go, and qu, by around 20–30% while improving the ductility index by 35–40%.

This article presents an experimental investigation on failure strengths and mechanical responses of transversely isotropic slates under the compressive differential cyclic loading. The tests involve five bedding orientations (0°, 30°, 45°, 60°, 90°) and two loading modes. The tests aim to investigate the coupled influence of the distinct loading/unloading rates and bedding orientation on the anisotropic characteristics, incl. the deformability, energy dissipation, damping ratio, phase shift and failure patterns. The results show that both loading modes and bedding angles have impacts on the mechanical responses of slates. Specifically, it is observed that rapid loading and slow unloading result in a higher growth rate of peak/residual strain versus cycle number as well as more intensive energy dissipation, and correspond to more significant phase shift. The influence of bedding angles on energy dissipation and strain is less pronounced compared to the effects of differential cyclic loading. The nuclear magnetic resonance was used to analyze the T2 spectra of the failed samples with different bedding angles.

Aging is the most important risk factor for the development of cardiovascular diseases. Senescent cells release plethora of factors commonly known as the senescence-associated secretory phenotype, which can modulate the normal function of the vascular wall. It is currently not well understood if and how endothelial cell senescence can affect adventitial niche. The aim of this study was to characterize oxidative stress-induced endothelial cells senescence and identify their paracrine effects on the primary cell type of the adventitia, the fibroblasts. Human aortic endothelial cells (HAEC) were treated with hydrogen peroxide to induce premature senescence. Mass spectrometry analysis identified several proteomic changes in senescent HAEC with top upregulated secretory protein growth differentiation factor 15 (GDF-15). Treatment of the human adventitial fibroblast cell line (hAdv cells) with conditioned medium (CM) from senescent HAEC resulted in alterations in the proteome of hAdv cells identified in mass spectrometry analysis. Majority of differentially expressed proteins in hAdv cells treated with CM from senescent HAEC were involved in the uptake and metabolism of lipoproteins, mitophagy and ferroptosis. We next analyzed if some of these changes and pathways might be regulated by GDF-15. We found that recombinant GDF-15 affected some ferroptosis-related factors (e.g. ferritin) and decreased oxidative stress in the analyzed adventitial fibroblast cell line, but it had no effect on erastin-induced cell death. Contrary, silencing of GDF-15 in hAdv cells was protective against this ferroptotic stimuli. Our findings can be of importance for potential therapeutic strategies targeting cell senescence or ferroptosis to alleviate vascular diseases.

To counteract global crises such as climate change or Covid-19, it is becoming increasingly important to make work systems more sustainable and resilient. This applies not only to ecological sustainability, but also to economic, social and security policy sustainability. Against this background, the task arises of critically reflecting on, adapting and further developing established research methods. In this theoretical paper, approaches to value-based system design and development were analyzed, with a particular focus on anchoring sustainability as a fundamental value in system design. Two models were developed that can provide an initial qualitative approach: The “angels diamond” diagram shows sustainability on the same level as time, costs, functions and quality described in the classical devil’s square diagram. The “holistic bow-tie model” shows the connections and interactions between a local sociotechnical system and its global metasystems like organizations, societies, and environment. The practical application of the models as part of a NATO workshop demonstrates the relevance and effectiveness of both models in the context of designing an AI-based safety system. Practical Relevance: The practical relevance of the contribution lies in the development and application of models that contribute to the systematic integration of sustainability aspects into the design of work systems. They make it possible to consider the effects on ecological, economic, social and security policy sustainability in system development decisions and promote a more comprehensive understanding of the interactions between local and global systems. The application of the models helps to analyze complex interactions and to make decisions about the ecological, economic and social impacts of products or systems.

Cognates are studied in many psychological studies of bilingual language processing. Despite their frequent use, there is no clear operationalized definition of what constitutes a cognate. We conducted a literature search in three major journals to better understand how cognate status is typically defined and operationalized. In these journals, we analyzed similarity of cognate and non-cognate stimuli. We found that approximately 60% of the reviewed studies operationalized cognate status empirically. Stimulus analyses revealed a similarity continuum between cognates and non-cognates without a consistent cut-off. Based on these results, we make recommendations for future research.

The coastal plain of Rio Grande do Sul state, in Brazil, is highly vulnerable to expected changes in sea level, while having an increasing population and consequently increasing water demands. Adequate management is essential to restrain contamination, depletion and salinization of the region’s aquifers considering current and future challenges, but geologic knowledge is essential to guide groundwater sustainable practices. To contribute to this discussion, this work integrated existing geological data from the northern coast of Rio Grande do Sul state to create a three-dimensional representation of the main hydrostratigraphical units of the region and its relation to the basement rocks, expanding the current knowledge of the coastal aquifer system. A review of existing data was carried out, consisting of 307 borehole logs from 13 municipalities inside the area of interest, as well as 19 vertical electrical soundings and 37 logs from oil and coal exploratory drillings, that resulted in 315 input points for the model. This work builds up on the conceptual model previously developed for the area, that defined four hydrostratigraphical units for the region, and was able to constrain the geometries of the main aquifers (unit 1 and 3) and aquitards (unit 2 and 4) and their relation to the basement rocks, showing them to be more heterogeneous in thicknesses and extent than previously thought. In addition, this work was able to model what could be a fifth hydrostratigraphical unit, that strongly differs from the other four and could be an indication of the alluvial fans previously described in the literature.

Charge-shift bonds have been hypothesized as a third type of chemical bonds in addition to covalent and ionic bonds. They have first been described with valence bond theory where they are identified by the resonance energy resulting from ionic contributions. While other indicators have been described, a clear real space fingerprint for charge-shift bonding is still lacking. Probability density analysis has been developed as a real space method, allowing chemical bonding to be identified from the many-electron probability density |Ψ|² where the wave function Ψ can be obtained from any quantum chemical method. Recently, barriers of a probability potential, which depends on this density, have proven to be good measures for delocalization and covalent bonding. In this work, we employ many examples to demonstrate that a well-suited measure for charge-shift bonding can be defined within the framework of probability density analysis. This measure correlates well with the charge-shift resonance energy from valence bond theory and thus strongly supports the charge-shift bonding concept. It is, unlike the charge-shift resonance energy, not dependent on a reference state. Moreover, it is independent of the polarity of the bond, suggesting to characterize bonds in molecules by both their polarity and their charge-shift character.

Maladaptive personality traits, such as ‘dark personalities’ are found to result in a diverse set of negative outcomes, including paraphilic interests and associated (illegal) behaviors. It is however unclear how these are exactly related, and if related, if then only those individuals higher on dark personality traits and higher impulsivity engage in paraphilic behaviors. In the current study, 50 participants were recruited to investigate the relationship between Dark Tetrad personality traits (i.e., narcissism, psychopathy, Machiavellianism and everyday sadism), paraphilic interests (arousal and behavior) and the moderating role of impulsivity. Personality and paraphilic interests were investigated through self-report questionnaires. Impulsivity was measured both through self-reported dysfunctional impulsivity and the P3 event related potential using electroencephalography during the Go/No-Go task (i.e. response inhibition). The results showed that there was a positive association between psychopathy, sadism and paraphilic interests. Whereas everyday sadism was associated with paraphilic (self-reported) arousal, psychopathy was associated with paraphilic behavior. Although P3 amplitude was not associated with paraphilic interests, self-reported dysfunctional impulsivity was associated with paraphilic behavior specifically. However, there was no moderating role of dysfunctional impulsivity and response inhibition (P3) in the relationship between psychopathy and paraphilic behavior. Findings indicate that the relation between specific dark personalities and paraphilic interests may be more complex than initially thought. Nevertheless, risk assessment and intervention approaches for paraphilia and related behavior both may benefit from incorporating Dark Tetrad and impulsivity measurements.

The metallurgical industry is a major source of anthropogenic greenhouse gas emissions. This study explores the replacement of fossil-reducing agents with potentially CO2-neutral bio-based reducing agents. Since reducing agents remove oxygen bonded with metal oxides present in the ore, they are a necessity for the production of metallic elements. The investigated metal is chromium, a major part of stainless steel, and therefore a highly relevant element for the transition from a fossil-based energy system to a renewable one. The state-of-the-art smelting reduction and pre-reduction process followed by subsequent smelting using various reducing agents are investigated in this article. The obtained products, metallurgical efficiencies, energy consumption and off-gas generation were compared. While the products produced with bio-based reducing agents are comparable with the reference trials using metallurgical coke regarding the major components in the metal, the concentration of detrimental phosphorus is significantly higher using bio-based reducing agents. The metallurgical efficiency of the process is comparable to the usage of bio-based reducing agents and coke. However, the energy consumption and the generation of off-gas is higher, when coke is replaced by bio-based reducing agents.

This study presents an in-depth spatiotemporal analysis of mangrove ecosystems along Egypt’s Red Sea coast, utilizing satellite imagery and GIS to examine changes from 2003 to 2022. We evaluate the effects of hydrological factors, specifically rainfall and runoff -presented by Stream Power Index-, on mangrove growth patterns. Results indicate a significant increase in mangrove areas, with a notable annual growth rate, despite a reduction in a specific region. This research highlights the integral role of catchment area runoff (R ² = 0.735, R = 0.857, P -value = 0.003 < 0.05, CV = 70.26%), rather than direct rainfall, in mangrove expansion, contributing to the understanding of mangrove resilience and informing sustainable coastal management strategies. The study bridges a significant research gap by mapping decadal mangrove changes, offering insights into the dynamics affecting these crucial ecosystems.

Callose is a vital component in plant biology, contributing to essential processes like pollen maturation and defense against pathogens. However, misconceptions surrounding callose staining persist, particularly regarding the role of aniline blue. It is now known that commercial aniline blue contains sirofluor, and it is this fluorophore, rather than aniline blue itself, that is responsible for the observed fluorescence during callose detection.

Traditional data monetization approaches face challenges related todata protection and logistics. In response, digital data marketplaceshave emerged as intermediaries simplifying data transactions. De-spite the growing establishment and acceptance of digital datamarketplaces, significant challenges hinder efficient data trading.As a result, few companies can derive tangible value from their data,leading to missed opportunities in understanding customers, pric-ing decisions, and fraud prevention. In this paper, we explore bothtechnical and organizational challenges affecting data monetization.Moreover, we identify areas in need of further research, aimingto expand the boundaries of current knowledge by emphasizingwhere research is currently limited or lacking.

Recent trends in numerical studies suggest the possible need for scale-resolving simulations for resolving shock oscillations on transonic compressors, the sources of which are unclear. The effect of promoting transition on the suction side upstream of self-sustained shock oscillations from a laminar shock/boundary-layer interaction (altitude conditions) in transonic compressors is studied using implicit large-eddy simulation, as well as experiments in a transonic cascade. The experiment is performed at conditions leading to different shock structures, and the shock behavior is captured with high-speed schlieren imaging. The Rolls-Royce HYDRA in-house code is employed for the numerical simulations. Trends in the change of oscillation behavior are discussed. The work addresses the fundamentally different behavior between an idealized quasi-2D LES case and an experimental cascade. This suggests that a simplification of the shock oscillation problem to a more canonical form is needed in order to investigate the oscillation mechanism itself experimentally and validate the CFD of the mechanism before returning to more complex cases. The reader is referred to youtu.be/CNRz7IYl1Pk for a condensed summary of the work with flow visualization.