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Significance of body acceleration and gold nanoparticles through blood flow in an uneven/composite inclined stenosis artery: A finite difference computation
No full textStenosis is a tiny plaque-like structure that builds up in the arterial wall owing to the sediment of cholesterol, fats, and pearly substances. Such inward proliferation in arteries significantly inhibits blood flow, which leads to a lack of nutrients and oxygen in the organs. Therefore, exploring the transport characteristics of blood fluid flow in stenosis arteries plays a prominent role in enhancing blood transportation. As a result, the present mathematical model is devoted to scrutinizing the flow of Sutterby gold blood nanofluid in two distinct stenosis arteries with periodic body acceleration. It is observed that the Sutterby rheology model is treated as blood, and the single-phase model is used for exposing the nanofluid behaviour. Dimensional non-linear PDEs of the current model are reduced to the set of dimensionless PDEs with the help of non-similar variables. A finite-difference approach is manipulated to compute the dimensionless PDEs. The physical features of governing flow parameters on the Sutterby nanofluid velocity, temperature, resistance impedance, flow rate, and wall shear stress are exposed through graphs. It is found that the composite stenosis has a lower wall shear stress than the irregular stenosis. Sutterby blood nanofluid velocity is elevated with the rising of nanoparticle volume fraction. When employing a gold nanofluid containing 5% volume fraction, the temperature in the irregular artery rises by 26.004% compared to the base fluid (blood). Similarly, in the composite artery, utilizing the same 5% volume fraction of the gold nanofluid leads to a temperature increase of 32.6207%. The blood flow pattern exhibits a 0.2340% higher in the irregular artery as compared to the composite artery. & COPY; 2023 International Association for Mathematics and Computers in Simulation (IMACS). Published by Elsevier B.V. All rights reserved
Ultrasound standing wave spatial patterning of human umbilical vein endothelial cells for 3D micro-vascular networks formation
No full textGenerating functional and perfusable micro-vascular networks is an important goal for the fabrication of large and three-dimensional tissues. Up to now, the fabrication of micro-vascular networks is a complicated multitask involving several different factors such as time consuming, cells survival, micro-diameter vasculature and strict alignment. Here, we propose a technique combining multi-material extrusion and ultrasound standing wave forces to create a network structure of human umbilical vein endothelial cells within a mixture of calcium alginate and decellularized extracellular matrix. The functionality of the matured microvasculature networks was demonstrated through the enhancement of cell-cell adhesion, angiogenesis process, and perfusion tests with microparticles, FITC-dextran, and whole mouse blood. Moreover, animal experiments exhibited the implantability including that the pre-existing blood vessels of the host sprout towards the preformed vessels of the scaffold over time and the microvessels inside the implanted scaffold matured from empty tubular structures to functional blood-carrying microvessels in two weeks
Synergistic effect of non-thermal plasma and CH4 addition on turbulent NH3/air premixed flames in a swirl combustor
No full textThe synergistic effect of non-thermal plasma (NTP) induced by a dielectric barrier discharge (DBD) and CH4 addition on turbulent swirl-stabilized NH3/air premixed flames in a laboratory-scale gas turbine combustor is experimentally investigated by varying the mixture equivalence ratio, ??, the mixt velocity, U0, and the mole fraction of CH4 in the fuel,
. It is found that the streamer intensity is significantly increased by adding CH4 to NH3/air flames compared with that by adding H2. This is because positive ions generated by CH4 addition play a critical role in generating streamers. Such streamers intensified by CH4 addition enhance the ammonia combustion more together with CH4, and hence, the lean blowout (LBO) limits of NH3/CH4/air flames are significantly extended compared with those without applying NTP. The maximum streamer intensity is found to be linearly proportional to
in wide ranges of ??,
, and U0. NTP is also found to significantly reduce the amount of NOx and CO emissions simultaneously. All of the results suggest that NTP can be used more effectively with CH4 addition to stabilize turbulent premixed NH3/air flames and reduce NOx/CO emissions, which is attributed to their synergistic effect on the ammonia combustion
Multi-objective robust parameter optimization using the extended and weighted k-means (EWK-means) clustering in laser powder bed fusion (LPBF)
No full textMetal additive manufacturing (AM) technology, especially laser powder bed fusion (LPBF), has received abundant interest from industries and the research community. Process optimization methods have thus multiplied to improve the overall quality of the final parts. However, little attention has been given to the quality repeatability issue. This paper proposes a novel multi-objective robust parameter optimization framework to explore optimal process parameters with respect to relative density and dimensional accuracy of LPBF-fabricated parts. Specifically, a modified k-means clustering, named the Extended and Weighted K-means (EWK-means), was constructed to simultaneously optimize the mean and the variance of the multiple responses. Experiments were conducted to verify the effectiveness of the proposed optimization framework. In addition, the effects of the process parameters, environment-related parameters, and physical properties on the hardness of the parts were analyzed using several machine learning models. The results showed that the proposed method achieved a set of optimal process parameters with better quality and satisfactory variability in the printed parts compared with other robust parameter optimization methods
EUSO-SPB1 mission and science
No full textThe Extreme Universe Space Observatory on a Super Pressure Balloon 1 (EUSO-SPB1) was launched in 2017 April from Wanaka, New Zealand. The plan of this mission of opportunity on a NASA super pressure balloon test flight was to circle the southern hemisphere. The primary scientific goal was to make the first observations of ultra-high-energy cosmic-ray extensive air showers (EASs) by looking down on the atmosphere with an ultraviolet (UV) fluorescence telescope from suborbital altitude (33 km). After 12 days and 4 h aloft, the flight was terminated prematurely in the Pacific Ocean. Before the flight, the instrument was tested extensively in the West Desert of Utah, USA, with UV point sources and lasers. The test results indicated that the instrument had sensitivity to EASs of (sic) 3 EeV. Simulations of the telescope system, telescope on time, and realized flight trajectory predicted an observation of about 1 event assuming clear sky conditions. The effects of high clouds were estimated to reduce this value by approximately a factor of 2. A manual search and a machine-learning-based search did not find any EAS signals in these data. Here we review the EUSO-SPB1 instrument and flight and the EAS search
On detecting the trivial rational 3-tangle
No full textAn important issue in classifying rational 3-tangles is how to know whether or not a given tangle is the trivial rational 3-tangle called infinity-tangle. The author [4] provided a certain algorithm to detect the infinity-tangle. In this paper, we give a much simpler method to detect the infinity-tangle by using the bridge arc replacement. We hope that this method can help prove many application problems such as a classification of 3-bridge knots.(c) 2023 Elsevier B.V. All rights reserved
Interaction mechanism between low molecular weight chitosan nanofilm and functionalized surfaces in aqueous solutions
No full textLow-molecular-weight chitosan (LMW chitosan, <10 kDa) have a significant potential for biomedical applications (e.g., antimicrobial and gene/drug delivery) because of their higher water solubility at pH values ranging from 3.0 to 8.5, compared to that of the high-molecular-weight (>100 kDa) chitosan. A comprehensive understanding of the LMW interaction mechanism with specific functional groups is necessary to predict their binding efficiency to other molecules for effectively utilizing their potential within biological systems. In this study, we used a surface forces apparatus (SFA) to investigate molecular interactions between LMW chitosan and four different functionalized self-assembled monolayers (SAMs) in aqueous solutions at pH values of 3.0, 6.5, and 8.5. Chitosan exhibited the strongest interaction energy with methyl-terminated SAM (CH3-SAM), indicating the significance of hydrophobic interaction. Many chitin/chitosan fibers in nature bind polyphenols (e.g., eumelanin) to form robust composites, which can be attributed to the strong attraction between chitosan and phenyl-SAM, presumably caused by cation????? interactions. These findings demonstrate the potential of modulating the magnitude of the interaction energy by controlling the solution pH and types of targeted functional groups to realize the optimal design of chitosan-based hybrid composites with other biomolecules or synthetic materials
Mapping techniques for collocation method of time-fractional convection???diffusion equations in domains with cracks
No full textThis paper proposes numerical methods that effectively deal with time-fractional convection???diffusion equations containing crack singularities. To deal with singularities, we design the geometrical mapping whose push-forward from the parameter space into the physical space generates point singularity functions based on the parametrization of the circular arc and NURBS (non-uniform rational B-spline). We adopt the collocation method with B-spline basis functions to approximate the solution in the spatial direction and enrich the approximation space by k-refinements in IGA (Isogeometric Analysis). For the discretization along the temporal direction, we employ the explicit Predictor-Corrector (PC) scheme that has the order and of the truncation error for the linear and quadratic interpolation, respectively. Taking advantage of the NURBS geometrical mapping, we demonstrate the performance of the proposed methods applying to time-fractional convection???diffusion equations with nonlinear terms on curved domains containing crack singularities
Leveraging ChatGPT and Bard: What does it convey for water treatment/desalination and harvesting sectors?
No full textArtificial intelligence (AI) has emerged as a prominent tool in the modern day. The utilization of AI and advanced language models such as chat generative pre-trained transformer (ChatGPT) and Bard is not only innovative but also crucial for handling challenges related to water research. ChatGPT is an AI chatbot that uses natural language processing to create humanlike conversations. ChatGPT has recently gained considerable public interest, owing to its unique ability to simplify tasks from various backgrounds. Similarly, Google introduced Bard, an AI-powered chatbot to simulate human conversations. Herein, we investigated how ChatGPT and Bard (AI powdered chatbots) tools can impact water research through interactive sessions. Typically, ChatGPT and Bard offer significant benefits to various fields, including research, education, scientific publications, and outreach. ChatGPT and Bard simplify complex and challenging tasks. For instance, 50 important questions about water treatment/desalination techniques and 50 questions about water harvesting techniques were provided to both chatbots. Time analytics was performed by ChatGPT 3.5, and Bard was used to generate full responses. In particular, the effectiveness of this emerging tool for research purposes in the field of conventional water treatment techniques, advanced water treatment techniques, membrane technology and seawater desalination has been thoroughly demonstrated. Moreover, potential pitfalls and challenges were also highlighted. Thus, sharing these experiences may encourage the effective and responsible use of Bard and ChatGPT in research purposes. Finally, the responses were compared from the perspective of an expert. Although ChatGPT and Bard possess huge benefits, there are several issues, which are discussed in this study. Based on this study, we can compare the abilities of artificial intelligence and human intelligence in water sector research
Enhancing catalytic performance and hot electron generation through engineering metal-oxide and oxide-oxide interfaces
No full textInterfaces are of utmost importance in catalytic reactions, influencing reaction kinetics and electron transfer processes. However, investigations in combined interfaces of metal-oxide and oxide-oxide at heterogeneous catalysts still have challenges due to their complex structure. Herein, we synthesized well-defined Co3O4 and CeO2 cubes with distinct facets and investigated their catalytic performance when deposited on a Pt-thin film, focusing on the influence of metal-oxide and oxide-oxide interfaces. Catalytic measurements demonstrated that the CeO2/Pt interface significantly enhanced turnover frequency (TOF) and selectivity for partial methanol oxidation compared to Co3O4/Pt and bare Pt. Notably, the CeO2/Co3O4/Pt nanodevice exhibited improved partial oxidation selectivity, highlighting the role of the CeO2/Co3O4 interface in methyl formate production. Chemicurrent measurements demonstrate enhanced hot electron generation due to increased overall TOF and partial oxidation production. We also conducted near ambient pressure X-ray photoelectron spectroscopy (NAPXPS) analysis, revealing a higher concentration of Ce3+ ions and increased oxygen vacancies in the CeO2/Co3O4/ Pt catalyst, suggesting oxygen migration from CeO2 to Co3O4, leading to methoxy species stabilization and promoting methyl formate formation