Mitigation of skull formation in high temperature gas extraction system

The adverse impact of particle adhesions and agglomerations on gas flow performance is a prominent concern in high volume extraction systems. The formation of severe skull deposits, involving agglomeration and adhesion processes, particularly at elevated operation temperatures, necessitates labor­intensive and costly manual removal. Consequently, investigating conditions that promote increased skull generation and exploring mechanisms for spontaneous removal through crack formation and chipping are of great significance. This study comprehensively documents the operational conditions of an industrial extraction system, accom panied by elemental gas phase composition analyses. Additionally, the chemical compositions of agglomerated adhesion samples were assessed using X­ray diffraction (XRD) and inductively coupled plasma optical emission spectroscopy (ICP­OES), and their inner structure was examined through SEM. Subsequently, mechanisms leading to these build­ups were simulated on laboratory scale by covering original wall surface samples with agglomeration powder screened for a defined particle size. In experiments conducted at various high temperatures ranging from 800 °C to 1200 °C, while varying the CaCO3 content levels in the powders, a layered structure similar to the real system was successfully acquired. Moreover, under certain defined conditions and different atmospheres, crack formation, significantly impacting the chipping behavior of the skull formations from wall surfaces during application, was observed and the compressive strength was examined. Through our laboratory experiments, specific operating conditions within the calcination cycle were revealed, leading to a substantial enhancement of autonomous discharge of large particleâwall agglomerations. Based on these findings, we propose general process optimization steps to improve the overall performance of the extraction system, such as reduction of fine CaCO3 particles and reduction of the gas flow temperature

The Determination of Immunomodulation and Its Impact on Survival of Rectal Cancer Patients Depends on the Area Comprising a Tissue Microarray.

BACKGROUND: T cell density in colorectal cancer (CRC) has proven to be of high prognostic importance. Here, we evaluated the influence of a hyperfractionated preoperative short-term radiation protocol (25 Gy) on immune cell density in tumor samples of rectal cancer (RC) patients and on patient survival. In addition, we assessed spatial tumor heterogeneity by comparison of analogue T cell quantification on full tissue sections with digital T cell quantification on a virtually established tissue microarray (TMA). METHODS: A total of 75 RC patients (60 irradiated, 15 treatment-naïve) were defined for retrospective analysis. RC samples were processed for immunohistochemistry (CD3, CD8, PD-1, PD-L1). Analogue (score 0-3) as well as digital quantification (TMA: 2 cores vs. 6 cores, mean T cell count) of marker expression in 2 areas (central tumor, CT; invasive margin, IM) was performed. Survival was estimated on the basis of analogue as well as digital marker densities calculated from 2 cores (Immunoscore: CD3/CD8 ratio) and 6 cores per tumor area. RESULTS: Irradiated RC samples showed a significant decrease in CD3 and CD8 positive T cells, independent of quantification mode. T cell densities of 6 virtual cores approximated to T cell densities of full tissue sections, independent of individual core density or location. Survival analysis based on full tissue section quantification demonstrated that CD3 and CD8 positive T cells as well as PD-1 positive tumor infiltrating leucocytes (TILs) in the CT and the IM had a significant impact on disease-free survival (DFS) as well as overall survival (OS). In addition, CD3 and CD8 positive T cells as well as PD-1 positive TILs in the IM proved as independent prognostic factors for DFS and OS; in the CT, PD-1 positive TILs predicted DFS and CD3 and CD8 positive T cells as well as PD-1 positive TILs predicted OS. Survival analysis based on virtual TMA showed no impact on DFS or OS. CONCLUSION: Spatial tumor heterogeneity might result in inadequate quantification of immune marker expression; however, if using a TMA, 6 cores per tumor area and patient sample represent comparable amounts of T cell densities to those quantified on full tissue sections. Consistently, the tissue area used for immune marker quantification represents a crucial factor for the evaluation of prognostic and predictive biomarker potential

Micro- and Nanoplastics Breach the Blood–Brain Barrier (BBB): Biomolecular Corona’s Role Revealed

Humans are continuously exposed to polymeric materials such as in textiles, car tires and packaging. Unfortunately, their break down products pollute our environment, leading to widespread contamination with micro- and nanoplastics (MNPs). The blood–brain barrier (BBB) is an important biological barrier that protects the brain from harmful substances. In our study we performed short term uptake studies in mice with orally administered polystyrene micro-/nanoparticles (9.55 µm, 1.14 µm, 0.293 µm). We show that nanometer sized particles—but not bigger particles—reach the brain within only 2 h after gavage. To understand the transport mechanism, we performed coarse-grained molecular dynamics simulations on the interaction of DOPC bilayers with a polystyrene nanoparticle in the presence and absence of various coronae. We found that the composition of the biomolecular corona surrounding the plastic particles was critical for passage through the BBB. Cholesterol molecules enhanced the uptake of these contaminants into the membrane of the BBB, whereas the protein model inhibited it. These opposing effects could explain the passive transport of the particles into the brain

Eine neue Methode zur Charakterisierung von industrielle Additive von Schmierstoffen in Triboschichten mittels AP-MALDI

Abweichender Titel nach Übersetzung der Verfasserin/des VerfassersKumulative Dissertation aus drei ArtikelnInformationen über das Verhalten von Additiven auf Oberflächen sind essentiell für eine Optimierung des Reibverhaltens von Systemkomponenten. Der Erkenntnisgewinn über Tribo-Prozesse und die Anwesenheit und Zusammensetzung der Triboschichten hilft Konzepte zu entwickeln, um das Reibungsverhalten und Additiveffizienz weiter optimieren zu können. Ziel dieser Arbeit soll es sein, eine neue Analysemethode (AP-MALDI-MS) zu etablieren, um Schmierstoff-Additive und eventuelle Reaktionsprodukte direkt auf tribologisch beanspruchten Oberflächen ohne weitere Separationsschritte nachweisen und charakterisieren zu können. Um zu zeigen, dass das Verständnis von Additivverhalten auf Oberflächen wesentlich für die Leistung tribologisch belasteter Systemkomponenten ist, wird eine Schadensanalyse von einem tribologisch stark beanspruchten Realsystem mittels ToF-SIMS und diversen weiteren Analysemethoden durchgeführt. Als neuartiger Ansatz zur Untersuchung von Schmierstoffadditiven auf Oberflächen wird AP-MALDI-MS zur Analyse herangezogen. Verschiedene ausgewählte Modelladditive werden in Reinform mit ESI-MS and AP-MALDI-MS und zusätzlich auch mit ToF-SIMS analysiert und verglichen. Um langwierige Separationsschritte zu umgehen, wird zusätzlich versucht die Modelladditive direkt aus einer Mischung mit einem Basisöl zu identifizieren. Diese Untersuchungen werden auf verschiedenen in der Industrie üblichen metallischen Oberflächen durchgeführt und der Einfluss der Rauigkeit auf die Intensitäten und Messbarkeit untersucht.In weiterer Folge werden einfache Triboversuche unter Verwendung der Modelladditive durchgeführt. Die Tribospur wird mittels neu entwickelter AP-MALDI-MS-Additivanalytik direkt gemessen werden. Unterstützt von ToF-SIMS und ESI-MS werden etwaige Reaktionsprodukte und Fragmente nachgewiesen und analysiert, um den Aufbau einer Triboschicht zu charakterisieren.Information on the behavior of additives on surfaces is essential for optimizing the friction behavior of system components. The knowledge gain about tribo processes and the presence and composition of the tribo layers will help to develop concepts to further optimize the friction behavior and additive efficiency. The aim of this work is to establish a new analytical method (AP-MALDI-MS) to detect and characterize lubricant additives and possible reaction products directly on tribologically stressed surfaces without further separation steps. In order to demonstrate that the understanding of additive behavior on surfaces is essential for the performance of tribologically loaded system components, a damage analysis of a tribologically stressed real system is performed using ToF-SIMS and various other surface analytical methods. As a novel approach for the investiagion of lubricant additives on surfaces AP-MALDI-MS is used for analysis. Various selected model additives are analyzed and compared in pure form with ESI-MS and AP-MALDI-MS as well as with ToF-SIMS. In order to avoid lengthy separation steps, an additional attempt is made to identifymodel additives directly from a blends of base oil. These investigations are carried out on various metallic surfaces common in industry and the influence of roughness on the intensities and measurability is investigated. Subsequently, simple tribo experiments are carried out using the model additives. The wear track will be measured directly using newly developed AP-MALDI-MS additive analysis. Supported by ToF-SIMS and ESI-MS, any reaction products and fragments are detected and analyzed to characterize the composition of boundary surface tribofilms.13

TOF-SIMS investigations of metal impurities in silicon

Zsfassung in dt. SpracheIn dieser Arbeit wurde Diffusion von Kupfer und Natrium in Silizium untersucht. zuerst wurden Gettering Effekte in Silizium Wafern untersucht. Durch Ionenimplantation und thermische Behandlung werden bestimmte Defekt in Silizium generiert. An diesen Fehlstellen werden diffundierende Kupferatome gesammelt. Dieses Verfahren wird benutzt um in Halbleiterbauteilen aktive Regionen frei von Verunreinigungen zu halten.Diese Messungen wurden durchgeführt um die Vergleichbarkeit des neuen TOF-SIMS Gerätes mit vorhergehenden Messungen zu überprüfen. Es wurden n-type und Bor-gedoptes Silizium untersucht, in das Sauerstoff, Phosphor oder Silizium Atome implantiert wurden.Der zweite Teil beschäftigt sich mit der Oberflächendiffusion von Natrium in Silizium. In dieser Arbeit werden einleitende Versuche zu Diffusion von Natriumverunreinigungen in Silizium durchgeführt.Alle Messungen wurden auf dem TOF-SIMS-Gerät der Arbeitsgruppe Prof.Herbert Hutter durchgeführt.In this work focus is on copper and sodium impurities in silicon. First, gettering effects in the silicon wafer bulk are investigated. Through ion implantation and annealing processes certain defects are produced in well controllable depths. Copper atoms diffusing through the wafer bulk gather at these lattice defect sites. This proximity gettering procedure is used to keep active device regions free of impurities. Recent investigations of this problem have been done on the previous SIMS (secondary ion mass spectrometry) instrument, so comparability to the use of the new TOF-SIMS instrument was examined.Two different types of silicon, n-type silicon and highly boron doped silicon, respectively, are used to investigate copper gettering behaviour of oxygen, phosphorus, and silicon ion implanted wafer structures. As a second subject of investigation surface diffusion of sodium into silicon was examined. Sodium is another impurity detrimental to semiconductor devices. It is almost ubiquitous and hardly controllable.During device manufacturing processes sodium consistently contaminates the silicon surface. In this paper, some preliminary studies of sodium diffusion after sodium containing molecules were applied onto the silicon wafer surface were conducted. Samples were annealed at various temperatures to investigate sodium diffusion barriers and behaviour.All our measurements were carried out using the fairly new ION-TOF5 instrument. Semiconductor industries work with highly pure silicon material, therefore already low concentrations of impurities can deteriorate the properties and characteristics of semiconductor devices.SIMS is an excellent analytic method to determine trace elements and impurities in metals and semiconductors due to its very low detection limits and the ability to measure depth profiles.8