Search results for "suodatus"
showing 10 items of 10 documents
Lignin recovery from spent alkaline pulping liquors using acidification, membrane separation, and related processing steps: A Review
2019
The separation of lignin from the black liquor generated during alkaline pulping is reviewed in this article with an emphasis on chemistry. Based on published accounts, the precipitation of lignin from spent pulping liquor by addition of acids can be understood based on dissociation equilibria of weak acid groups, which affects the solubility behavior of lignin-related chemical species. Solubility issues also govern lignin separation technologies based on ultrafiltration membranes; reduction in membrane permeability is often affected by conditions leading to decreased solubility of lignin decomposition products and the presence of colloidal matter. Advances in understanding of such phenomen…
Is Aquaponics Beneficial in Terms of Fish and Plant Growth and Water Quality in Comparison to Separate Recirculating Aquaculture and Hydroponic Syste…
2022
Aquaponics is a technique where a recirculating aquaculture system (RAS) and hydroponics are integrated to grow plants and fish in a closed system. We investigated if the growth of rainbow trout (Oncorhynchus mykiss) and baby spinach (Spinacia oleracea) would be affected in a coupled aquaponic system compared to the growth of the fish in RAS or plants in a hydroponic system, all systems as three replicates. We also investigated the possible effects of plants on the onset of nitrification in biofilters and on the concentration of off-flavor-causing agents geosmin (GSM) and 2-methylisoborneol (MIB) in rainbow trout flesh and spinach. For the fish grown in aquaponics, the weight gain and speci…
Datan analysointi verkkokauppojen suosittelujärjestelmissä big datan konteks-tissa
2015
Tämä tutkielma keskittyy suosittelujärjestelmien yleiseen toimintaperiaattee-seen ja niiden tarjoamiin hyötyihin. Suosittelujärjestelmien toiminta täyttää Big datalle ominaiset piirteet, mistä syystä asiaa lähestytään Big datan analysointi-na. Tarkoituksena on antaa lukijalle yleiskuva suosittelujärjestelmistä, niiden toimintaperiaatteesta ja käyttötarkoituksesta. Tutkielmassa käsitellään suositte-lujärjestelmistä yhteisöllistä, yhteistoimintapohjaista, demografista ja tietä-myspohjaista suodatusta sekä hybridejä variaatioita. Lisäksi kerrotaan suositte-lujärjestelmien tarjoamista hyödyistä nimenomaan palveluntarjoajan näkökul-masta. Tutkielma on toteutettu kirjallisuuskatsauksena. Lähdeain…
Microbiome response to foam fractionation and ozonation in RAS
2022
Efficient water treatment is required to maintain high water quality and control microbial growth in recirculating aquaculture systems (RAS). Here, we examined the effects of two treatment methods, ozonation and foam fractionation, separately and combined, on the microbiology in twelve identical experimental RAS with rainbow trout (Oncorhyncus mykiss) during 8 weeks. Microbes suspended in water and growing in biofilter biofilms were examined using flow cytometry analysis and high throughput sequencing of the 16S rRNA gene. The results showed that foam fractionation did not cause large changes in abundance or overall community composition of free-living microbes. Instead, through decreasing …
Käyttäjien profilointi verkkokaupoissa : viitekehysmalli profilointimenetelmien vertailuun
2006
Comparing ranking-based collaborative filtering algorithms to a rating-based alternative in recommender systems context
2017
Suuri sisältövalikoima eri internet palveluissa, kuten verkkokaupoissa, voi aiheuttaa liian suurta informaatiomäärää, mikä heikentää asiakaskokemusta. Suosittelujärjestelmät ovat teknologioita, jotka tukevat asiakkaan päätöksentekoa tarjoamalla ennustettuja suosituksia. On yleistä, että asiakkaalle näytetään lista tuotteista, joista asiakas voisi pitää, esimerkiksi top-10 lista elokuvista. Perinteisesti nämä listat ovat tuotettu käyttäen perinteistä arvosanapohjaista menetelmää, missä tuntemattomille tuotteille ennustetaan arvosana ja järjestetty lista muodostetaan arvosanojen perusteella. Sijoitusperusteinen lähestyminen laskee käyttäjien väliset samankaltaisuudet ja ennustaa järjestetyn l…
The effects of different combinations of fixed and moving bed bioreactors on rainbow trout (Oncorhynchus mykiss) growth and health, water quality and…
2019
The effect of bioreactor design on nitrification efficiency has been well studied, but less is known about the overall impacts on water quality. Besides nitrification, submerged fixed bed bioreactors (FBBR) trap fine solid particles, whereas moving bed bioreactors (MBBR) grind solids, possibly increasing solids and particle accumulation in the system. In this experiment, the effects of different combinations of fixed bed and moving bed bioreactors on water quality, solids removal, particle size distribution, fish health based on histopathological changes and nitrification efficiency were studied in laboratory scale recirculating aquaculture systems (RAS) with rainbow trout (Oncorhynchus myk…
The effects of different combinations of fixed and moving bed bioreactors on rainbow trout (Oncorhynchus mykiss) growth and health, water quality and…
2019
Abstract The effect of bioreactor design on nitrification efficiency has been well studied, but less is known about the overall impacts on water quality. Besides nitrification, submerged fixed bed bioreactors (FBBR) trap fine solid particles, whereas moving bed bioreactors (MBBR) grind solids, possibly increasing solids and particle accumulation in the system. In this experiment, the effects of different combinations of fixed bed and moving bed bioreactors on water quality, solids removal, particle size distribution, fish health based on histopathological changes and nitrification efficiency were studied in laboratory scale recirculating aquaculture systems (RAS) with rainbow trout (Oncorhy…
Does the freshwater mussel Anodonta anatina remove the fish pathogen Flavobacterium columnare from water?
2021
AbstractGlobal decline of freshwater mussels (Unionoida) is threatening biodiversity and the essential ecosystem services that mussels provide. As filter-feeding organisms, freshwater mussels remove phytoplankton and suspended particles from the water. By filtering bacteria, freshwater mussels also decrease pathogen loads in the water. The objective of this study was to evaluate whether the common freshwater bivalve Anodonta anatina (duck mussel) could remove the bacterial fish pathogen Flavobacterium columnare from the water. Mussels reduced bacteria in both of the two experiments performed, so that the bacterial concentration at the end of the 96-h monitoring in mussel treatments was only…
Tracing activation efficiency of the bio-filtration bacteria in a recirculating aquaculture system using stable isotope analysis
2016
One challenge in starting a new recirculation aquaculture system (RAS) is to find the most efficient method to activate the nitrifying bacterial biofilm in the bio-filtration system. It has been suggested that chemical startup with ammonia and nitrite surpasses the “cold start” method where biofilm originates from the fish introduced to the un-activated system. However, there is no information on how the start-up method affects the actual nitrification activity of the bio- filtration system. The objectives of this study were to evaluate how different activation techniques affect the overall function and the nitrification activity of the bio-filtration units, and the interactions between het…