Global existence of weak and classical solutions for the Navier–Stokes–Vlasov–Fokker–Planck equations

AbstractWe consider a system coupling the incompressible Navier–Stokes equations to the Vlasov–Fokker–Planck equation. The coupling arises from a drag force exerted by each other. We establish existence of global weak solutions for the system in two and three dimensions. Furthermore, we obtain the existence and uniqueness result of global smooth solutions for dimension two. In case of three dimensions, we also prove that strong solutions exist globally in time for the Vlasov–Stokes system

Nitrate Leaching from Sand and Pumice Geomedia Amended with Pyrogenic Carbon Materials

There is increasing interest in using pyrogenic carbon as an adsorbent for aqueous contaminants in stormwater. The objective of this study was to investigate pyrogenic carbon materials as an amendment to geomedia to reduce nitrate leaching. Batch adsorption and column experiments were conducted to evaluate the performance of a commercial activated carbon and two biochars incorporated (5% by weight) into sand and pumice columns. The batch adsorption with 50 mg L−1 of nitrate solution showed that only activated carbon resulted in a substantial adsorption for nitrate up to 41%. Tested biochars were not effective in removing aqueous nitrate and even released nitrate.Tested biochars were not effective in removing aqueous nitrate and even released nitrate (\u3c1%) with 1 h reaction time. Column experiment with a pulse input of nitrate solution (50 mg L−1) confirmed that the sand or pumice columns amended with biochars were not as effective as those amended with activated carbon for reducing nitrate leaching. Our results suggested that net negatively charged surfaces of biochar may inhibit nitrate anion adsorption while activated carbon has reactive sites containing acidic functional groups to improve nitrate retention. There was no difference between sand and pumice for nitrate retention in any of the carbon amendments. Additional surface activation process during biochar production may be needed to improve adsorptive capacity of biochar for aqueous nitrate removal

Notes on the Global Well-Posedness for the Maxwell-Navier-Stokes System

Masmoudi (2010) obtained global well-posedness for 2D Maxwell-Navier-Stokes system. In this paper, we reprove global existence of regular solutions to the 2D system by using energy estimates and Brezis-Gallouet inequality. Also we obtain a blow-up criterion for solutions to 3D Maxwell-Navier-Stokes system

Sand and pumice filter amended with activated carbon and biochar for phosphorus retention

Phosphorus (P) loss via stormwater runoff is a water quality concern. The objective of this study was to investigate two commercial biochars relative to an activated carbon as an additive to geomedia (sand and pumice) for P removal. The batch adsorption experiment was conducted to assess P sorption of the geomedia and carbon materials while the leaching experiment was conducted in sand and pumice columns amended with carbon materials (5 % by weight). The batch adsorption test revealed that only activated carbon showed an appreciable P adsorption up to 19 %. Tested biochar materials showed no adsorption capacity for P and rather released P. The leaching experiment with the P solution (16.3 mg L-1) confirmed that AC-amended sand or pumice columns were more effective in P retention than those amended with biochars. Our results indicated that pristine biomass-based biochars have a limited adsorption for anionic pollutants such as P probably due to limited metal-containing functional groups while activated carbon has reactive functional groups. Future studies for aqueous P removal using biochar should consider surface modification of biochars using metal salts and/or metal-containing feedstock such as biosolids to improve their performance on aqueous P removal

Adsorptive and kinetic characterization of aqueous zinc removal by biochars

Biochars have shown a great potential to treat stormwater runoff contaminated with heavy metals due to their favorable physical and chemical characteristics. Biochar materials were produced from pyrolysis of oak tree and wood at 400C and 450C respectively, and their Zn adsorption behavior from aqueous solutions were evaluated to assess their applicability as a filter media for stormwater treatment. Two adsorption isotherm models, Freundlich and Langmuir, were used to fit the batch-scale experimental data. The kinetics of Zn adsorption was investigated under two contrasting physical condition (stagnant vs. agitated). The adsorption isotherm was better fitted with the Langmuir model (R2 = 0.99) than the Freundlich model (R2 = 0.62-0.72). Oak tree biochar (~ 21,400 mg kg-1) outperformed wood biochar (~ 6,100 mg kg-1) in the Zn adsorption due to higher molar ratio of oxygen to carbon in the oak tree biochar. The Zn adsorption by the biochars were less effective under stagnant condition, suggesting that external energy for agitation is needed when considering biochar as a stormwater filter media. Overall the kinetics data of Zn adsorption fitted well with the pseudo-second order model (R2 = 0.99), indicating that chemisorption was dominant mechanism for the Zn adsorption onto the biochars. This study highlights a potential for biochar to be an effective adsorbent to remove Zn with relatively short contact time for stormwater and industrial applications

Studija o analizi međuodnosa između Epa o Gilgamešu i Biblije pomoću rudarenja teksta; fokusiranje na epizodu velikog potopa

The development of human civilization is a continuous process of imitation and creation  based on exchange. Most historical research is performed qualitatively, so consequently, historical interpretations tend to be biased with personal or subjective viewpoints. In this context, Bible is the most-read book in history and comparative studies are steadily conducted owing to its similarities with the myths of ancient civilizations. This study combines qualitative and quantitative analysis to analyze the interrelationship between a myth and the Bible. Specifically, intertextuality analysis was performed around the great flood episode in Mesopotamia’s Epic of Gilgamesh and the Bible’s Genesis. Text mining–based association rule analysis and word cloud analysis were combined to verify this. Intertextuality analysis revealed the interrelationship between the Epic of Gilgamesh and the Bible; moreover, text mining helped verify the association in intertextuality analysis. Through this, the study proposes a research method for civilization exchange studies by objectively approaching the flow and directionality of exchanges among civilizations in the ancient Mediterranean regions. Furthermore, along with civilization exchange studies, a practical convergent research method for studies in the areas of humanities, regional studies, and history was suggested.Razvoj ljudske civilizacije kontinuirani je proces oponašanja i stvaranja temeljen na razmjeni. Većina povijesnih istraživanja provodi se kvalitativno, zbog čega su povijesne interpretacije nerijetko pristrane, s osobnim ili subjektivnim stajalištima. U tom pogledu Biblija je najčitanija knjiga u povijesti te su komparativne studije često rađene zbog njezinih sličnosti s mitovima drevnih civilizacija. Ova studija kombinira kvalitativnu i kvantitativnu analizu kako bi analizirala međuodnos između mita i Biblije. Točnije, analiza intertekstualnosti provedena je na osnovi epizode velikog potopa u mezopotamskom Epu o Gilgamešu i biblijskom Postanku. Analiza pravila asocijacija temeljena na rudarenju teksta i analiza oblaka riječi kombinirane su kako bi se to potvrdilo. Kao rezultat analize intertekstualnosti, potvrđeno je da je otkriven međuodnos između Epa o Gilgamešu i Biblije, a kao rezultat rudarenja teksta, povezanost se može provjeriti u analizi intertekstualnosti. Slijedom rezultata studija predlaže istraživačku metodu za proučavanje civilizacijske razmjene objektivnim pristupom tijeku i usmjerenosti razmjene među civilizacijama u drevnim mediteranskim regijama. Štoviše, uz studije civilizacijske razmjene, predložena je praktična konvergentna istraživačka metoda za studije u područjima humanističkih znanosti, regionalnih studija i povijesti

Performance Comparison of Design Optimization and Deep Learning-based Inverse Design

Surrogate model-based optimization has been increasingly used in the field of engineering design. It involves creating a surrogate model with objective functions or constraints based on the data obtained from simulations or real-world experiments, and then finding the optimal solution from the model using numerical optimization methods. Recent advancements in deep learning-based inverse design methods have made it possible to generate real-time optimal solutions for engineering design problems, eliminating the requirement for iterative optimization processes. Nevertheless, no comprehensive study has yet closely examined the specific advantages and disadvantages of this novel approach compared to the traditional design optimization method. The objective of this paper is to compare the performance of traditional design optimization methods with deep learning-based inverse design methods by employing benchmark problems across various scenarios. Based on the findings of this study, we provide guidelines that can be taken into account for the future utilization of deep learning-based inverse design. It is anticipated that these guidelines will enhance the practical applicability of this approach to real engineering design problems