Simulationsgestützte Analyse eines Wertstroms als Beitrag zu nachhaltigen Produktions- und Logistiksystemen von KMUs

In crises, small and medium-sized enterprises (SMEs) are under more significant pressure than large companies. However, SMEs are more adaptable to changes caused by external influences. To leverage this strength, the focus is on increasing transparency, identifying bottlenecks in the material flow, and evaluating a defined target state of the material flow based on company-specific key performance indicators (KPIs) for sustainable production. Varieties of different methods are suitable for determining these KPIs. In this paper, a simulation-based analysis is performed to determine such indicators. For this purpose, an application example from practice illustrates these methods' applicability to increase the SMEs' adaptability to external influencing factors. First, a value stream analysis of the current state of the material flow is performed. Based on the results, suggestions for changes are given and implemented in a new optimized value stream. A simulation study compares the new value stream with the current one

Metal-Dependent and Selective Crystallization of CAU-10 and MIL-53 Frameworks through Linker Nitration

The reaction of the V-shaped linker molecule 5-hydroxyisophthalic acid (H2 L0 ), with Al or Ga nitrate under almost identical reaction conditions leads to the nitration of the linker and subsequent formation of metal-organic frameworks (MOFs) with CAU-10 or MIL-53 type structure of composition [Al(OH)(L)], denoted as Al-CAU-10-L0, 2, 4, 6 or [Ga(OH)(L)], denoted as Ga-MIL-53-L2 . The Al-MOF contains the original linker L0 as well as three different nitration products (L2 , L4 and L4/6 ), whereas the Ga-MOF mainly incorporates the linker L2 . The compositions were deduced by 1 H NMR spectroscopy and confirmed by Rietveld refinement. In situ and ex situ studies were carried out to follow the nitration and crystallization, as well as the composition of the MOFs. The crystal structures were refined against powder X-ray diffraction (PXRD) data. As anticipated, the use of the V-shaped linker results in the formation of the CAU-10 type structure in the Al-MOF. Unexpectedly, the Ga-MOF crystallizes in a MIL-53 type structure, which is usually observed with linear or slightly bent linker molecules. To study the structure directing effect of the in situ nitrated linker, pure 2-nitrobenzene-1,3-dicarboxylic acid (m-H2 BDC-NO2 ) was employed which exclusively led to the formation of [Ga(OH)(C8 H3 NO6 )] (Ga-MIL-53-m-BDC-NO2 ), which is isoreticular to Ga-MIL-53-L2 . Density Functional Theory (DFT) calculations confirmed the higher stability of Ga-MIL-53-L2 compared to Ga-CAU-10-L2 and grand canonical Monte Carlo simulations (GCMC) are in agreement with the observed water adsorption isotherms of Ga-MIL-53-L2

Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe

Nrf2-interacting nutrients and COVID-19 : time for research to develop adaptation strategies

There are large between- and within-country variations in COVID-19 death rates. Some very low death rate settings such as Eastern Asia, Central Europe, the Balkans and Africa have a common feature of eating large quantities of fermented foods whose intake is associated with the activation of the Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) anti-oxidant transcription factor. There are many Nrf2-interacting nutrients (berberine, curcumin, epigallocatechin gallate, genistein, quercetin, resveratrol, sulforaphane) that all act similarly to reduce insulin resistance, endothelial damage, lung injury and cytokine storm. They also act on the same mechanisms (mTOR: Mammalian target of rapamycin, PPAR gamma:Peroxisome proliferator-activated receptor, NF kappa B: Nuclear factor kappa B, ERK: Extracellular signal-regulated kinases and eIF2 alpha:Elongation initiation factor 2 alpha). They may as a result be important in mitigating the severity of COVID-19, acting through the endoplasmic reticulum stress or ACE-Angiotensin-II-AT(1)R axis (AT(1)R) pathway. Many Nrf2-interacting nutrients are also interacting with TRPA1 and/or TRPV1. Interestingly, geographical areas with very low COVID-19 mortality are those with the lowest prevalence of obesity (Sub-Saharan Africa and Asia). It is tempting to propose that Nrf2-interacting foods and nutrients can re-balance insulin resistance and have a significant effect on COVID-19 severity. It is therefore possible that the intake of these foods may restore an optimal natural balance for the Nrf2 pathway and may be of interest in the mitigation of COVID-19 severity

Inter- and Transdisciplinary Collaboration in an International Research Project – The Case of the German-Ghanaian Project EnerSHelF (Energy-Self-Sufficiency for Health Facilities in Ghana)

Interdisciplinary research (IDR) is a widely applied research approach, combing the efforts of multiple academic disciplines to work on complex problems. Within transdisciplinary research (TDR), non-academic stakeholders participate in the project and offer hands-on experience to the research. These integrative approaches are praised for the ability for addressing ‘wicked problems’ and can lead to new perspectives on relevant contemporary challenges. This working paper is analysing the cooperation and exchange of involved disciplines in the German-Ghanaian interdisciplinary research project Energy-Self-Sufficiency for Health Facilities in Ghana (EnerSHelF). The results are presented in a Collaboration Frequency Network (CFN) as well as qualitatively examined to unravel the level of interaction and perspectives on chances and challenges of IDR and TDR. The analysis shows that disciplinary closeness, data collection and exchange, and individual effort are affecting the level of collaboration among other reasons. Concluding the authors develop recommendations for future IDR and TDR projects

Direct Observation of Deformation in Microgel Filtration

Colloidal filtration processes using porous membranes suffer from productivity loss due to colloidal matter retention and continuous build-up by the retained matter. Especially during filtration of soft matter, the deformation of the individual colloids that make up the filter cake may be significant; however, this deformation and its impact remain unresolved so far. Yet, understanding the deformation on the single colloid level as well as on the ensemble level is important to be able to deconvolute filter cake properties from resistance increase of the membrane either by simultaneous internal adsorption or blocking of pores. Here, we report on the compression of a filter cake by filtrating soft microgels in a microfluidic channel in front of a model membrane. To study the single colloid deformation amorphous and crystalline domains were built up in front of the membrane and visualized on-line using confocal fluorescence microscopy while adjusting the degree of permeation, i.e., the transmembrane flux. Results show locally pronounced asymmetric deformation in amorphous domains, while the microgels in colloidal crystals approached regular polyeder shape. Increasing the flux beyond the maximum colloid deformation results in non-isochoric microgel behavior. The presented methodology enables a realistic description of complex colloidal matter deposits during filtration