Numerical Prediction and Validation of Suspension Flows and its Erosive Effect

Erosive wear occurs in many fields of materials handling technology; e.g., during transportation of bulk materials or suspensions, when particles collide with the walls of material handling components such as ducts or pumps. The severity of wear is closely determined by both, component materials and the flow conditions in the medium. Hence a prediction of the wear needs a combination of Computational Fluid Dynamics (CFD) and a Finite Element Method (FEM) that offers realistic simulation of erosion in materials handling components. This paper presents an approach to calculate particle trajectories of a suspension flow. The particle trajectories of a suspension flow are simulated using CFD and experimentally validated. The presented results are part of a project attributed to the VDMA Pumps + Systems which includes the erosion simulation using FEM [1]. The presented approach contributes to the pre-development of material handling components such as pumps and offers valuable assistance to manufactures. This allows a time- and costefficient development of wear-resistant components

Oxidative stress and inflammation distinctly drive molecular mechanisms of diastolic dysfunction and remodeling in female and male heart failure with preserved ejection fraction rats

Heart failure with preserved ejection fraction (HFpEF) is a complex cardiovascular insufficiency syndrome presenting with an ejection fraction (EF) of greater than 50% along with different proinflammatory and metabolic co-morbidities. Despite previous work provided key insights into our understanding of HFpEF, effective treatments are still limited. In the current study we attempted to unravel the molecular basis of sex-dependent differences in HFpEF pathology. We analyzed left ventricular samples from 1-year-old female and male transgenic (TG) rats homozygous for the rat Ren-2 renin gene (mRen2) characterized with hypertension and diastolic dysfunction and compared it to age-matched female and male wild type rats (WT) served as control. Cardiomyocytes from female and male TG rats exhibited an elevated titin-based stiffness (Fpassive), which was corrected to control level upon treatment with reduced glutathione indicating titin oxidation. This was accompanied with high levels of oxidative stress in TG rats with more prominent effects in female group. In vitro supplementation with heat shock proteins (HSPs) reversed the elevated Fpassive indicating restoration of their cytoprotective function. Furthermore, the TG group exhibited high levels of proinflammatory cytokines with significant alterations in apoptotic and autophagy pathways in both sexes. Distinct alterations in the expression of several proteins between both sexes suggest their differential impact on disease development and necessitate distinct treatment options. Hence, our data suggested that oxidative stress and inflammation distinctly drive diastolic dysfunction and remodeling in female and male rats with HFpEF and that the sex-dependent mechanisms contribute to HF pathology

Higher thyrotropin leads to unfavorable lipid profile and somewhat higher cardiovascular disease risk: evidence from multi-cohort Mendelian randomization and metabolomic profiling.

BACKGROUND: Observational studies suggest interconnections between thyroid status, metabolism, and risk of coronary artery disease (CAD), but causality remains to be proven. The present study aimed to investigate the potential causal relationship between thyroid status and cardiovascular disease and to characterize the metabolomic profile associated with thyroid status. METHODS: Multi-cohort two-sample Mendelian randomization (MR) was performed utilizing genome-wide significant variants as instruments for standardized thyrotropin (TSH) and free thyroxine (fT4) within the reference range. Associations between TSH and fT4 and metabolic profile were investigated in a two-stage manner: associations between TSH and fT4 and the full panel of 161 metabolomic markers were first assessed hypothesis-free, then directional consistency was assessed through Mendelian randomization, another metabolic profile platform, and in individuals with biochemically defined thyroid dysfunction. RESULTS: Circulating TSH was associated with 52/161 metabolomic markers, and fT4 levels were associated with 21/161 metabolomic markers among 9432 euthyroid individuals (median age varied from 23.0 to 75.4 years, 54.5% women). Positive associations between circulating TSH levels and concentrations of very low-density lipoprotein subclasses and components, triglycerides, and triglyceride content of lipoproteins were directionally consistent across the multivariable regression, MR, metabolomic platforms, and for individuals with hypo- and hyperthyroidism. Associations with fT4 levels inversely reflected those observed with TSH. Among 91,810 CAD cases and 656,091 controls of European ancestry, per 1-SD increase of genetically determined TSH concentration risk of CAD increased slightly, but not significantly, with an OR of 1.03 (95% CI 0.99-1.07; p value 0.16), whereas higher genetically determined fT4 levels were not associated with CAD risk (OR 1.00 per SD increase of fT4; 95% CI 0.96-1.04; p value 0.59). CONCLUSIONS: Lower thyroid status leads to an unfavorable lipid profile and a somewhat increased cardiovascular disease risk

RA-MAP, molecular immunological landscapes in early rheumatoid arthritis and healthy vaccine recipients

Rheumatoid arthritis (RA) is a chronic inflammatory disorder with poorly defined aetiology characterised by synovial inflammation with variable disease severity and drug responsiveness. To investigate the peripheral blood immune cell landscape of early, drug naive RA, we performed comprehensive clinical and molecular profiling of 267 RA patients and 52 healthy vaccine recipients for up to 18 months to establish a high quality sample biobank including plasma, serum, peripheral blood cells, urine, genomic DNA, RNA from whole blood, lymphocyte and monocyte subsets. We have performed extensive multi-omic immune phenotyping, including genomic, metabolomic, proteomic, transcriptomic and autoantibody profiling. We anticipate that these detailed clinical and molecular data will serve as a fundamental resource offering insights into immune-mediated disease pathogenesis, progression and therapeutic response, ultimately contributing to the development and application of targeted therapies for RA.</p

Strömungsinduzierte Schwingungen durchströmter Hubventile

In industriellen Anlagen werden Hubventile eingesetzt, um Stoffströme zu regulieren. Im durchströmten Hubventil können Schwingungen im Betrieb entstehen, die zum Stillstand der Anlage führen. Das Hubventil setzt sich aus einem Gehäuse, der Ventilgarnitur, bestehend aus Ventilstange mit angeschraubten Drosselkörper und Ventilsitz sowie dem Gehäusedeckel, in dem die Lagerung der Ventilstange untergebracht ist, zusammen. Das Hubventil regelt den Stoffstrom, indem es seinen Strömungswiderstand anpasst. Der Strömungswiderstand wird durch Heraus- oder Hineinfahren des Drosselkörpers in den Ventilsitz eingestellt. Dabei wird die Strömung in den Spalt zwischen Drosselkörper und Ventilsitz beschleunigt und beim Verlassen des Spaltes verzögert. In der Dissertation wird die Hypothese aufgestellt, dass die Spaltströmung zwischen Drosselkörper und Ventilsitz der Grund für selbsterregte Schwingungen des Hubventils ist. Zur Überprüfung dieser Hypothese werden umfangreiche experimentelle Parameterstudien durchgeführt, bei denen die radiale Bewegung des Drosselkörpers in der Ebene und damit die transversale Schwingung der Ventilstange erfasst werden. Die Experimente zeigen Schwingungen der Ventilstange nahe ihrer Biegeeigenfrequenzen. Dabei bestätigen die Experimente teilweise die Berechnungsergebnisse, deren Grundlage ein Eigenwertproblem darstellt. Das aufgestellte Berechnungsmodell zeigt einen deutlichen Einfluss der Neigung zwischen Drosselkörper und Ventilsitz auf die Schwingungen des Ventils. Eine messtechnische Erfassung der Neigung des Drosselkörpers war jedoch nicht möglich. Die Rechenzeit des aufgestellten Modells ist im Vergleich zu dreidimensionalen Fluid-Struktur-Simulation drastisch reduziert und kann daher zur Auslegung von Hubventilen wirtschaftlich eingesetzt werden

A fresh outlook

[No abstract available

Strömungsinduzierte Schwingungen in Regelarmaturen

Regelarmaturen werden eingesetzt, um Stoffströme in Anlagen durch Drosselung zu regeln. Die gewünschte Drosselwirkung ist Hauptauslegungskriterium einer Armatur. Die Armatur wird jedoch nicht auf ihr Schwingverhalten im Betrieb untersucht. Die Wechselwirkung zwischen der elastischen Struktur einer Armatur und der Strömung des durchfließenden Mediums kann zu erheblichen Schäden an der Armatur führen. Um Schadensfälle und Ausfallzeiten zu verringern, wird das Problem strömungsinduzierter Schwingungen in Regelarmaturen am Institut für Fluidsystemtechnik der TU Darmstadt experimentell wie auch analytisch untersucht. Erste Ergebnisse dazu beschreibt der folgende Beitrag