CFD Simulation of Flow and Temperature inside a monolith of an Exhaust After-Treatment System (EATS)

Internal Combustion Engine is the most popular and efficient types of engine used in the transport sector. On the other hand, it has serious downside in degrading the environmental stability as well. The exhaust gases after the combustion of fuel contain emissions which are harmful for human health and responsible for the climate change. Treating the exhaust gases of an Internal Combustion Engine is a major operation in the vehicle. Exhaust After Treatment System engineering simply known as EATS, can treat and remove these substances from the engine exhaust. Although the applied technology in EATS engineering are already very efficient, it is of interest to gather more knowledge about the velocity and temperature distributions inside the monolith of the reactor during transient operation to further improve the efficiency. By using computer aided simulations to capture the fine details, CFD has become a vital part to gain high resolution data in the monolith channels inside an EATS with the single channel approach. However, due to the computational cost, solving for a complete EATS with high resolution is not yet a possibility. The idea behind this research is to find a small set of channels which can be modelled to represent a complete EATS. Hence, using the single channel approach on the selected channels, these can represent a high resolution EATS simulation. The goal of this project was mainly focusing on obtaining high detailed simulations of ow and temperature for a specially designed monolithic catalytic reactor in transient state. A range of air ow and temperatures were tested in a laboratory, where the ow and temperatures in the inlet and outlet of monolith were recorded. The same ow conditions were reproduced with CFD simulations and a verification for the CFD model was done by comparing these results. A D-optimal algorithm was used on the outlet data of simulated ow tests, to find the optimal four locations for the different cases. Finally, a weighting model was developed where the four locations represent the complete outlet

Mesenchymal Stem Cell-Derived Extracellular Vesicles in Tendon and Ligament Repair-A Systematic Review of In Vivo Studies.

Tendon and ligament injury poses an increasingly large burden to society. This systematic review explores whether mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) can facilitate tendon/ligament repair in vivo. On 26 May 2021, a systematic search was performed on PubMed, Web of Science, Cochrane Library, Embase, to identify all studies that utilised MSC-EVs for tendon/ligament healing. Studies administering EVs isolated from human or animal-derived MSCs into in vivo models of tendon/ligament injury were included. In vitro, ex vivo, and in silico studies were excluded, and studies without a control group were excluded. Out of 383 studies identified, 11 met the inclusion criteria. Data on isolation, the characterisation of MSCs and EVs, and the in vivo findings in in vivo models were extracted. All included studies reported better tendon/ligament repair following MSC-EV treatment, but not all found improvements in every parameter measured. Biomechanics, an important index for tendon/ligament repair, was reported by only eight studies, from which evidence linking biomechanical alterations to functional improvement was weak. Nevertheless, the studies in this review showcased the safety and efficacy of MSC-EV therapy for tendon/ligament healing, by attenuating the initial inflammatory response and accelerating tendon matrix regeneration, providing a basis for potential clinical use in tendon/ligament repair

A Tale of Two Major Postwar Business Cycle Episodes

We offer a tale of two major postwar business cycle episodes: the pre-1980s and the post-1982s prior to the Great Recession. We revisit the sources of business cycles and the reasons for the large variations in aggregate volatility from the first to the second episode. Using a medium-scale DSGE model where monetary policy potentially has cost-channel effects, we first show the Fed most likely targeted deviations of output growth from trend growth, not the output gap, for measure of economic activity. When estimating our model with a policy rule reacting to output growth with Bayesian techniques, we find the US economy was not in a state of indeterminacy in either of the two subperiods. Thus, aggregate instability before 1980 did not result from self-fulfilling changes in inflation expectations. Our evidence shows the Fed reacted more strongly to inflation after 1982. Based on sub-period estimates, we find that shocks to the marginal efficiency of investment largely drove the cyclical variance of output growth prior to 1980 (61%), while they have seen their importance falls dramatically after 1982 (19%). When looking at the sources of greater macroeconomic stability during the second episode, we find no support for the “good-luck hypothesis”. Change in nominal wage flexibility largely drove the decline in output growth volatility, while the change in monetary policy was a key factor lowering inflation variability

Adipose Tissue-Derived Mesenchymal Stem Cells as a Potential Restorative Treatment for Cartilage Defects: A PRISMA Review and Meta-Analysis.

Cartilage defects are a predisposing factor for osteoarthritis. Conventional therapies are mostly palliative and there is an interest in developing newer therapies that target the disease's progression. Mesenchymal stem cells (MSCs) have been suggested as a promising therapy to restore hyaline cartilage to cartilage defects, though the optimal cell source has remained under investigation. A PRISMA systematic review was conducted utilising five databases (MEDLINE, EMBASE, Cochrane Library, Scopus, Web of Science) which identified nineteen human studies that used adipose tissue-derived MSC (AMSC)-based therapies, including culture-expanded AMSCs and stromal vascular fraction, to treat cartilage defects. Clinical, imaging and histological outcomes, as well as other relevant details pertaining to cartilage regeneration, were extracted from each study. Pooled analysis revealed a significant improvement in WOMAC scores (mean difference: -25.52; 95%CI (-30.93, -20.10); p < 0.001), VAS scores (mean difference: -3.30; 95%CI (-3.72, -2.89); p < 0.001), KOOS scores and end point MOCART score (mean: 68.12; 95%CI (62.18, 74.05)), thus showing improvement. The studies in this review demonstrate the safety and efficacy of AMSC-based therapies for cartilage defects. Establishing standardised methods for MSC extraction and delivery, and performing studies with long follow-up should enable future high-quality research to provide the evidence needed to bring AMSC-based therapies into the market

Teaching Programming and Design-by-Contract

This paper summarizes the experience of teaching an introductory course to programming by using a correctness by construction approach at Innopolis University, Russian Federation. In this paper we claim that division in beginner and advanced groups improves the learning outcomes, present the discussion and the data that support the claim.Comment: 21th International Conference on Interactive Collaborative Learnin

Laparoscopic Heminephrectomy of a Horseshoe Kidney

These authors suggest that laparoscopic heminephrectomy is a feasible option in the surgical management of diseases of the horseshoe kidney and can be performed safely using a transperitoneal or retroperitoneal approach

Run ‐ to ‐Run Control of ITO Deposition Process

This paper describes the design and development of run‐to‐run control solution for an Indium Tin Oxide (ITO) deposition process. ITO deposition is an inherently complex process making it hard to simultaneously optimize the many characteristics of the ITO film such as optical transmission, resistivity, stresses in the film etc. With the run‐to‐run control solution, post‐process measurements made after every run are used along with empirical process models and drift compensation and noise rejection techniques to suggest new equipment settings for the next run. Theoretical models and simulation results show that this approach gives very stable ITO characteristics. Some of the methods that improve the control algorithm are discussed and future work is explored.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92093/1/1.1833812.pd

Enhanced Tissue Integration During Cartilage RepairIn VitroCan Be Achieved by Inhibiting Chondrocyte Death at the Wound Edge

Objective: Experimental wounding of articular cartilage results in cell death at the lesion edge. The objective of this study was to investigate whether inhibition of this cell death results in enhanced integrative cartilage repair. Methods: Bovine articular cartilage discs (6mm) were incubated in media containing inhibitors of necrosis (Necrostatin-1, Nec-1) or apoptosis (Z-VAD-FMK, ZVF) before cutting a 3mm inner core. This core was left in situ to create disc/ring composites, cultured for up to 6 weeks with the inhibitors, and analyzed for cell death, sulfated glycosaminoglycan release, and tissue integration. Results: Creating the disc/ring composites resulted in a significant increase in necrosis. ZVF significantly reduced necrosis and apoptosis at the wound edge. Nec-1 reduced necrosis. Both inhibitors reduced the level of wound-induced sulfated glycosaminoglycan loss. Toluidine blue staining and electron microscopy of cartilage revealed significant integration of the wound edges in disc/ring composites treated with ZVF. Nec-1 improved integration, but to a lesser extent. Push-out testing revealed that ZVF increased adhesive strength compared to control composites. Conclusions: This study shows that treatment of articular cartilage with cell death inhibitors during wound repair increases the number of viable cells at the wound edge, prevents matrix loss, and results in a significant improvement in cartilage-cartilage integration