scholarly journals Gas Mixing and Final Mixture Composition Control in Simple Geometry Micro-mixers via DSMC Analysis

Micromachines ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 178 ◽  
Author(s):  
Stavros Meskos ◽  
Stefan Stefanov ◽  
Dimitris Valougeorgis
Keyword(s):  
Relative Density ◽  
Molecular Mass ◽  
Hard Sphere ◽  
Density Difference ◽  
Mixture Composition ◽  
Minor Effect ◽  
Mixing Length ◽  
Mass Ratio ◽  
Gas Mixing ◽  
A Minor

The mixing process of two pressure driven steady-state rarefied gas streams flowing between two parallel plates was investigated via DSMC (Direct Simulation Monte Carlo) for different combinations of gases. The distance from the inlet, where the associated relative density difference of each species is minimized and the associated mixture homogeneity is optimized, is the so-called mixing length. In general, gas mixing progressed very rapidly. The type of gas surface interaction was clearly the most important parameter affecting gas mixing. As the reflection became more specular, the mixing length significantly increased. The mixing lengths of the HS (hard sphere) and VHS (variable hard sphere) collision models were higher than those of the VSS (variable soft sphere) model, while the corresponding relative density differences were negligible. In addition, the molecular mass ratio of the two components had a minor effect on the mixing length and a more important effect on the relative density difference. The mixture became less homogenous as the molecular mass ratio reduced. Finally, varying the channel length and/or the wall temperature had a minor effect. Furthermore, it was proposed to control the output mixture composition by adding in the mixing zone, the so-called splitter, separating the downstream flow into two outlet mainstreams. Based on intensive simulation data with the splitter, simple approximate expressions were derived, capable of providing, once the desired outlet mixture composition was specified, the correct position of the splitter, without performing time consuming simulations. The mixing analysis performed and the proposed approach for controlling gas mixing may support corresponding experimental work, as well as the design of gas micro-mixers.

Hindrance to diffusive gas mixing in the lung in hyperbaric environments

1981 ◽  
Vol 51 (2) ◽  
pp. 243-247 ◽  
Author(s):  
H. D. Van Liew ◽  
E. D. Thalmann ◽  
D. K. Sponholtz
Keyword(s):  
Atmospheric Pressure ◽  
Minor Effect ◽  
Gas Mixing ◽  
Positive Relation ◽  
Single Breath ◽  
Molecular Diffusivity ◽  
Residual Capacity ◽  
Residual Gas ◽  
A Minor ◽  
Diffusive Mixing

Diffusivity of a gas is inversely proportional to atmospheric pressure. We studied pulmonary gas mixing in hyperbaric environments (5.5 and 9.5 ATA) as a means of understanding the role played by diffusion in normal situations and also as a means of determining whether persons in hyperbaric environments will be handicapped by poor diffusive mixing. Our subjects took single breaths of a mixture of indicator gases (5% each of SF6, Ar, Ne, and He; 20% O2, balance N2). Recordings of expired volumes and concentrations showed that heavier indicators were less well mixed than lighter ones, as evidenced by a slower fall during the transition between dead space and "alveolar" gas and a steeper slope of the alveolar plateau. Differences between light and heavy gases increased as pressure increased. Amounts of the indicators retained in the functional residual capacity (FRC) or residual volume after a single breath had a weak positive relation to diffusivity; the amounts (A) in the FRC (as fraction of inspired amounts) were well fitted by a simple equation. ARFC/AI = 0.55 - (0.0010/D), where D is molecular diffusivity. We conclude that the changes of distribution of inspired gas that occur with large changes of diffusivity have only a minor effect on the amount of gas exchanged between the inspirate and residual gas in the FRC.

Improvement of monitoring of tertiary filtration with particle counting

2006 ◽  
Vol 6 (1) ◽  
pp. 1-9
Author(s):  
V. Miska ◽  
J.H.J.M. van der Graaf ◽  
J. de Koning
Keyword(s):  
Particle Surface ◽  
Minor Effect ◽  
Particle Size Distributions ◽  
Particle Volume ◽  
Mass Distributions ◽  
Particle Counting ◽  
Total Particle ◽  
Particle Counts ◽  
A Minor ◽  
Sample Dilution

Nowadays filtration processes are still monitored with conventional analyses like turbidity measurements and, in case of flocculation–filtration, with phosphorus analyses. Turbidity measurements have the disadvantage that breakthrough of small flocs cannot be displayed, because of the blindness regarding changes in the mass distributions. Additional particle volume distributions calculated from particle size distributions (PSDs) would provide a better assessment of filtration performance. Lab-scale experiments have been executed on a flocculation–filtration column fed with effluent from WWTP Beverwijk in The Netherlands. Besides particle counting at various sampling points, the effect of sample dilution on the accuracy of PSD measurements has been reflected. It was found that the dilution has a minor effect on PSD of low turbidity samples such as process filtrate. The correlation between total particle counts, total particle volume (TPV) and total particle surface is not high but is at least better for diluted measurements of particles in the range 2–10 μm. Furthermore, possible relations between floc-bound phosphorus and TPV removal had been investigated. A good correlation coefficient is found for TPV removal versus floc-bound phosphorus removal for the experiments with polyaluminiumchloride and the experiments with single denitrifying and blank filtration.

scholarly journals Linkage mapping identifies a non-synonymous mutation in FLOWERING LOCUS T (FT-B1) increasing spikelet number per spike

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan Brassac ◽  
Quddoos H. Muqaddasi ◽  
Jörg Plieske ◽  
Martin W. Ganal ◽  
Marion S. Röder
Keyword(s):  
Flowering Time ◽  
Aspartic Acid ◽  
Synonymous Substitution ◽  
Minor Effect ◽  
Phenotypic Variance ◽  
Spikelet Number ◽  
Wheat Varieties ◽  
Trait Locus ◽  
A Minor ◽  
Spikelet Number Per Spike

AbstractTotal spikelet number per spike (TSN) is a major component of spike architecture in wheat (Triticumaestivum L.). A major and consistent quantitative trait locus (QTL) was discovered for TSN in a doubled haploid spring wheat population grown in the field over 4 years. The QTL on chromosome 7B explained up to 20.5% of phenotypic variance. In its physical interval (7B: 6.37–21.67 Mb), the gene FLOWERINGLOCUST (FT-B1) emerged as candidate for the observed effect. In one of the parental lines, FT-B1 carried a non-synonymous substitution on position 19 of the coding sequence. This mutation modifying an aspartic acid (D) into a histidine (H) occurred in a highly conserved position. The mutation was observed with a frequency of ca. 68% in a set of 135 hexaploid wheat varieties and landraces, while it was not found in other plant species. FT-B1 only showed a minor effect on heading and flowering time (FT) which were dominated by a major QTL on chromosome 5A caused by segregation of the vernalization gene VRN-A1. Individuals carrying the FT-B1 allele with amino acid histidine had, on average, a higher number of spikelets (15.1) than individuals with the aspartic acid allele (14.3) independent of their VRN-A1 allele. We show that the effect of TSN is not mainly related to flowering time; however, the duration of pre-anthesis phases may play a major role.

scholarly journals IL-6 Is Not Absolutely Essential for the Development of a TH17 Immune Response after an Aerosol Infection with Mycobacterium tuberculosis H37rv

Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Kristina Ritter ◽  
Jan Christian Sodenkamp ◽  
Alexandra Hölscher ◽  
Jochen Behrends ◽  
Christoph Hölscher
Keyword(s):  
Immune Response ◽  
Inflammatory Diseases ◽  
Mycobacterial Infection ◽  
Minor Effect ◽  
Mycobacterium Tuberculosis H37rv ◽  
Th 17 ◽  
Anti Inflammatory ◽  
A Minor ◽  
Aerosol Infection ◽  
Deficient Mice

Anti-inflammatory treatment of chronic inflammatory diseases often increases susceptibility to infectious diseases such as tuberculosis (TB). Since numerous chronic inflammatory and autoimmune diseases are mediated by interleukin (IL)-6-induced T helper (TH) 17 cells, a TH17-directed anti-inflammatory therapy may be preferable to an IL-12-dependent TH1 inhibition in order to avoid reactivation of latent infections. To assess, however, the risk of inhibition of IL-6-dependent TH17-mediated inflammation, we examined the TH17 immune response and the course of experimental TB in IL-6- and T-cell-specific gp130-deficient mice. Our study revealed that the absence of IL-6 or gp130 on T cells has only a minor effect on the development of antigen-specific TH1 and TH17 cells. Importantly, these gene-deficient mice were as capable as wild type mice to control mycobacterial infection. Together, in contrast to its key function for TH17 development in other inflammatory diseases, IL-6 plays an inferior role for the generation of TH17 immune responses during experimental TB.

scholarly journals Sweet taste of heavy water

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Natalie Ben Abu ◽  
Philip E. Mason ◽  
Hadar Klein ◽  
Nitzan Dubovski ◽  
Yaron Ben Shoshan-Galeczki ◽  
...  
Keyword(s):  
Heavy Water ◽  
Calcium Release ◽  
Homology Modelling ◽  
Taste Receptor ◽  
Chemical Properties ◽  
Sweet Taste ◽  
Minor Effect ◽  
Dynamics Simulations ◽  
A Minor ◽  
Physical And Chemical

AbstractHydrogen to deuterium isotopic substitution has only a minor effect on physical and chemical properties of water and, as such, is not supposed to influence its neutral taste. Here we conclusively demonstrate that humans are, nevertheless, able to distinguish D2O from H2O by taste. Indeed, highly purified heavy water has a distinctly sweeter taste than same-purity normal water and can add to perceived sweetness of sweeteners. In contrast, mice do not prefer D2O over H2O, indicating that they are not likely to perceive heavy water as sweet. HEK 293T cells transfected with the TAS1R2/TAS1R3 heterodimer and chimeric G-proteins are activated by D2O but not by H2O. Lactisole, which is a known sweetness inhibitor acting via the TAS1R3 monomer of the TAS1R2/TAS1R3, suppresses the sweetness of D2O in human sensory tests, as well as the calcium release elicited by D2O in sweet taste receptor-expressing cells. The present multifaceted experimental study, complemented by homology modelling and molecular dynamics simulations, resolves a long-standing controversy about the taste of heavy water, shows that its sweet taste is mediated by the human TAS1R2/TAS1R3 taste receptor, and opens way to future studies of the detailed mechanism of action.

scholarly journals Effect of Different SiO2 Polymorphs on the Reaction Between SiO2 and SiC in Si Production

2021 ◽  
Vol 52 (2) ◽  
pp. 792-803
Author(s):  
Marit Buhaug Folstad ◽  
Eli Ringdalen ◽  
Halvard Tveit ◽  
Merete Tangstad
Keyword(s):  
Amorphous Silica ◽  
Reaction Rate ◽  
Reduction Reaction ◽  
Minor Effect ◽  
Target Temperature ◽  
Heating Rates ◽  
Significant Difference ◽  
Sio2 Polymorphs ◽  
A Minor ◽  
Final Composition

AbstractThis work investigates the phase transformations in silica (SiO2) during heating to a target temperature between 1700 °C and 1900 °C and the effect of SiO2 polymorphs on the reduction reaction 2SiO2 + SiC = 3SiO + CO in silicon production. Different heating rates up to target temperature have been used to achieve the different compositions of quartz, amorphous silica and cristobalite. The different heating rates had a minor effect on the final composition, and longer time at temperatures > 1400 °C were necessary to achieve greater variations in the final composition. Heating above the melting temperature gave more amorphous silica and less cristobalite, as amorphous silica also may form from β-cristobalite. Isothermal furnace experiments were conducted to study the extent of the reduction reaction. This study did not find any significant difference in the effects of quartz, amorphous silica or cristobalite. Increased temperature from 1700 °C to 1900 °C increased the reaction rate.

OP65 Pharmacoeconomic Evaluation Of Orphan Drugs: Impact Of Extra Criteria?

2019 ◽  
Vol 35 (S1) ◽  
pp. 16-16
Author(s):  
Orla Maguire ◽  
Laura McCullagh ◽  
Cara Usher ◽  
Michael Barry
Keyword(s):  
Cost Effectiveness ◽  
Orphan Drug ◽  
Societal Perspective ◽  
Evaluation Process ◽  
Orphan Drugs ◽  
Pharmacoeconomic Evaluation ◽  
Qaly Gain ◽  
Minor Effect ◽  
Orphan Medicinal Products ◽  
A Minor

IntroductionThere is ongoing debate as to whether conventional pharmacoeconomic evaluation (PE) methods are appropriate for orphan medicinal products (OMPs). The National Centre for Pharmacoeconomics (NCPE) in Ireland has a well-defined process for conducting pharmacoeconomic evaluations of pharmaceuticals, which is the same for OMPs and non-OMPs. The objective of this study was to identify whether supplementary criteria considered in the pharmacoeconomic evaluation of OMPs would affect final reimbursement recommendations.MethodsA literature search was conducted to identify criteria. Orphan drug pharmacoeconomic evaluations completed by the NCPE between January 2015 and December 2017 were identified and supplementary criteria, where feasible, were applied.ResultsFourteen pharmacoeconomic evaluations were included in the study. Three criteria that could feasibly be applied to the NCPE evaluation process were identified, all three of which essentially broadened the economic perspective of the pharmacoeconomic evaluation. Higher cost-effectiveness threshold: Despite being arbitrarily raised from EUR 45,000/QALY to EUR 100,000/QALY, only one orphan drug demonstrated cost-effectiveness at this higher threshold. Weighted QALY gain: here, a weighted gain of between one and three is applied to drugs demonstrating QALY gains between 10 and 30, respectively. No OMPs included in the study showed a QALY gain of more than 10. Thirteen demonstrated QALY gains less than 10 and one could not be evaluated. Societal perspective: six submissions incorporated societal perspective as a scenario analysis. Despite incremental cost-effectiveness ratios (ICERs) being reduced between 4 percent and 58 percent, only two OMPs demonstrated cost-effectiveness at the higher threshold (EUR 100,000/QALY).ConclusionsApplication of supplementary criteria to the pharmacoeconomic evaluation of OMPs had a minor effect on three products assessed. However, for the majority, the final cost-effectiveness outcomes remained the same. The study highlights that other criteria are being considered in the decision to reimburse.

Hardness Evolution and High Temperature Mechanical Properties of Laser Welded DP980 Steel Joints

2018 ◽  
Vol 37 (6) ◽  
pp. 587-595
Author(s):  
Zhandong Wan ◽  
Wei Guo ◽  
Qiang Jia ◽  
Lang Xu ◽  
Peng Peng
Keyword(s):  
Yield Strength ◽  
Energy Absorption ◽  
Base Metal ◽  
Welded Joint ◽  
Dynamic Strain ◽  
Minor Effect ◽  
Fiber Laser Welding ◽  
Fine Grained ◽  
High Temperature Mechanical Properties ◽  
A Minor

AbstractDP980 steels were joined using fiber laser welding. The welded joint was characterized in terms of hardness distribution and tensile behavior at room temperature, 150 ℃, and 300 ℃, respectively. The fine-grained martensite in supercritical heat affected zone (HAZ) resulted in the highest hardness (428 Hv), while the tempered martensite contributed to the hardness decreasing (‒31 Hv). Both the ultimate tensile strength and yield strength of the base metal and welded joint decreased at 150 ℃, and then increased at 300 ℃ due to dynamic strain aging (DSA). The welded joint exhibited slightly higher yield strength and lower elongation at all the test temperatures compared to base metal due to the hardened fusion zone. The energy absorption reduced slightly with increasing temperature both for base metal and welded joint, and the weld posed a minor effect on the energy absorption. Deformation was one of the requirements for DSA effect. DSA enhanced the hardness of base metal (+78 Hv) and softened zone (+53 Hv). HAZ was not softened enough to become the weakest position during tensile test.

scholarly journals Cross-linking of the electron-transfer flavoprotein to electron-transfer flavoprotein-ubiquinone oxidoreductase with heterobifunctional reagents

1988 ◽  
Vol 255 (3) ◽  
pp. 869-876 ◽  
Author(s):  
D J Steenkamp
Keyword(s):  
Electron Transfer ◽  
Small Subunit ◽  
Cross Linking ◽  
Minor Effect ◽  
Electron Transfer Flavoprotein ◽  
Ubiquinone Oxidoreductase ◽  
Lysine Residues ◽  
Cross Links ◽  
A Minor ◽  
Chemical Cross Linking

The mitochondrial electron-transfer flavoprotein (ETF) is a heterodimer containing only one FAD. In previous work on the structure-function relationships of ETF, its interaction with the general acyl-CoA dehydrogenase (GAD) was studied by chemical cross-linking with heterobifunctional reagents [D. J. Steenkamp (1987) Biochem. J. 243, 519-524]. GAD whose lysine residues were substituted with 3-(2-pyridyldithio)propionyl groups was preferentially cross-linked to the small subunit of ETF, the lysine residues of which had been substituted with 4-mercaptobutyramidine (MBA) groups. This work was extended to the interaction of ETF with ETF-ubiquinone oxidoreductase (ETF-Q ox). ETF-Q ox was partially inactivated by modification with N-succinimidyl 3-(2-pyridyldithio)propionate to introduce pyridyl disulphide structures. A similar modification of ETF caused a large increase in the apparent Michaelis constant of ETF-Q ox for modified ETF owing to the loss of positive charge on some critical lysines of ETF. When ETF-Q ox was modified with 2-iminothiolane to introduce 4-mercaptobutyramidine groups, only a minor effect on the activity of the enzyme was observed. To retain the positive charges on the lysine residues of ETF, pyridyl disulphide structures were introduced by treating ETF with 2-iminothiolane in the presence of 2,2′-dithiodipyridyl. The electron-transfer activity of the resultant ETF preparation containing 4-(2-pyridyldithio)butyramidine (PDBA) groups was only slightly affected. When ETF-Q ox substituted with MBA groups was mixed with ETF bearing PDBA groups, at least 70% of the cross-links formed between the two proteins were between the small subunit of ETF and ETF-Q ox. ETF-Q ox, therefore, interacts predominantly with the same subunit of ETF as GAD. Variables which affect the selectivity of ETF-Q ox cross-linking to the subunits of ETF are considered.

Differences in solubility parameters and susceptibility to salting-out between softwood and hardwood lignosulfonates

Holzforschung ◽  
2016 ◽  
Vol 70 (11) ◽  
pp. 1015-1021 ◽  
Author(s):  
Bernt O. Myrvold
Keyword(s):  
Molecular Weight ◽  
Salt Tolerance ◽  
Plant Species ◽  
Post Treatment ◽  
Solubility Parameters ◽  
Minor Effect ◽  
Hofmeister Series ◽  
Salt Tolerant ◽  
Salting Out ◽  
A Minor

Abstract The salting-out of lignosulfonates (LSs) follows the Hofmeister series, but different LSs show different susceptibility to salting-out. By comparing results for a large number of LSs from different plant species, pulping conditions, and post-treatment of the LS, it was found that the salting-out concentration for different LSs is mainly due to differences in the plant species with guaiacyl LS being much more salt-tolerant than guaiacyl-syringyl LS. The pulping conditions have only a minor effect on the salt tolerance of the different LSs. Post-treatment that increases the molecular weight or reduces the sulfonation also reduces the salt tolerance.

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