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

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.

2016 ◽  
Vol 11 (S321) ◽  
pp. 283-283
Author(s):  
Thomas Martinsson ◽  
Marc Verheijen ◽  
Matthew Bershady ◽  
Kyle Westfall ◽  
David Andersen ◽  
...  

AbstractWe present results on luminous and dark matter mass distributions in disk galaxies from the DiskMass Survey. As expected for normal disk galaxies, stars dominate the baryonic mass budget in the inner region of the disk; however, at about four optical scale lengths (hR) the atomic gas starts to become the dominant contributor. Unexpectedly, we find the total baryon to dark-matter fraction within a galaxy stays nearly constant with radius from 1hR out to at least 6hR, with a baryon fraction of 15–50% among galaxies. On average, only one third of the mass within 2.2hR in a disk galaxy is baryonic and these baryons appear to have had only a minor effect on the distribution of the dark matter.


2011 ◽  
Vol 4 (3) ◽  
pp. 557-570 ◽  
Author(s):  
F. Cairo ◽  
G. Di Donfrancesco ◽  
M. Snels ◽  
F. Fierli ◽  
M. Viterbini ◽  
...  

Abstract. An FSSP-100 Optical Particle Counter designed to count and size particles in the micron range and a backscattersonde that measures in-situ particle optical properties such as backscatter and depolarization ratio, are part of the payload of the high altitude research aircraft M55 Geophysica. This aircraft was deployed in tropical field campaigns in Bauru, Brasil (TROCCINOX, 2004) Darwin, Australia (SCOUT-Darwin, 2005) and Ouagadougou, Burkina Faso (SCOUT-AMMA, 2006). In those occasions, measurements of particle size distributions and optical properties within cirrus cloud were performed. Scope of the present work is to assess and discuss the consistency between the particle volume backscatter coefficient observed by the backscattersonde and the same parameter retrieved by optical scattering theory applied to particle size distributions as measured by the FSSP-100. In addition, empirical relationships linking the optical properties measured in-situ by the backscattersonde, which generally can be obtained by remote sensing techniques (LIDAR), and microphysical bulk properties like total particle number, surface and volume density will be presented and discussed.


2010 ◽  
Vol 3 (5) ◽  
pp. 4059-4089 ◽  
Author(s):  
F. Cairo ◽  
G. Di Donfrancesco ◽  
M. Snels ◽  
F. Fierli ◽  
M. Viterbini ◽  
...  

Abstract. An FSSP-100 Optical Particle Counter designed to count and size particles in the micron range and a backscattersonde that measures in-situ particle optical properties such as backscatter and depolarization ratio, are part of the payload of the high altitude research aircraft M55 Geophysica. This aircraft was deployed in tropical field campaigns in Bauru, Brasil (TROCCINOX, 2004) Darwin, Australia (SCOUT-Darwin, 2005) and Ouagadougou, Burkina Faso (SCOUT-AMMA, 2006). In those occasions, measurements of particle size distributions and optical properties within cirrus cloud were performed. Scope of the present work is to assess and discuss the consistency between the particle volume backscatter coefficient observed by the backscattersonde and the same parameter retrieved by optical scattering theory applied to particle size distributions as measured by the FSSP-100. In addition, empirical relationships linking the optical properties measured in-situ by the backscattersonde, which generally can be obtained by remote sensing techniques (LIDAR), and microphysical bulk properties like total particle number, surface and volume density will be presented and discussed.


1987 ◽  
Vol 44 (11) ◽  
pp. 1898-1914 ◽  
Author(s):  
Henry A. Vanderploeg ◽  
Brian J. Eadie ◽  
James R. Liebig ◽  
Stephen J. Tarapchak ◽  
Rebecca M. Glover

We determined the contribution of calcite to the total particle-size spectrum of Lake Michigan seston during different seasons in 1978–83 and 1985, employing a novel Coulter counter method, to examine the intensity and ecological effects of calcite whitings that result from autogenic precipitation of calcite. The whitings were most intense during September, when 12–56% of the total particle volume was calcite. Overall, food web dynamics were more controlling of than controlled by whitings. Year-to-year variation in calcite concentration was probably caused by predation-controlled variation in primary production, which drives calcite precipitation through CO2 uptake. Feeding rate of cladocerans in Lake Michigan is slightly reduced (16%) by calcite, but that of copepods is not. Light extinction is only slightly increased. Coprecipitation and sinking of P with calcite is probably a minor factor in regulating P concentration in the epilimnion of Lake Michigan. Removal of nutrients is enhanced by increased sinking rates caused by inclusion of calcite in fecal pellets and matter. Although all of the effects of calcite on plankton dynamics appear to be subtle in Lake Michigan, large effects can be expected for lakes of greater calcium hardness and eutrophy.


Author(s):  
Eaton E. Lattman ◽  
Thomas D. Grant ◽  
Edward H. Snell

In this chapter we note that solution scattering data can be divided into four regions. At zero scattering angle, the scattering provides information on molecular weight of the particle in solution. Beyond that, the scattering is influenced by the radius of gyration. As the scattering angle increases, the scattering is influenced by the particle shape, and finally by the interface with the particle and the solution. There are a number of important invariants that can be calculated directly from the data including molecular mass, radius of gyration, Porod invariant, particle volume, maximum particle dimension, particle surface area, correlation length, and volume of correlation. The meaning of these is described in turn along with their mathematical derivations.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonathan Brassac ◽  
Quddoos H. Muqaddasi ◽  
Jörg Plieske ◽  
Martin W. Ganal ◽  
Marion S. Röder

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.


Cells ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Kristina Ritter ◽  
Jan Christian Sodenkamp ◽  
Alexandra Hölscher ◽  
Jochen Behrends ◽  
Christoph Hölscher

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.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Natalie Ben Abu ◽  
Philip E. Mason ◽  
Hadar Klein ◽  
Nitzan Dubovski ◽  
Yaron Ben Shoshan-Galeczki ◽  
...  

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.


2021 ◽  
Vol 52 (2) ◽  
pp. 792-803
Author(s):  
Marit Buhaug Folstad ◽  
Eli Ringdalen ◽  
Halvard Tveit ◽  
Merete Tangstad

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.


2019 ◽  
Vol 35 (S1) ◽  
pp. 16-16
Author(s):  
Orla Maguire ◽  
Laura McCullagh ◽  
Cara Usher ◽  
Michael Barry

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.


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