Search results for " tanks"
showing 10 items of 26 documents
Teaching Green Analytical Chemistry on the Example of Bioindication and Biomonitoring (B & B) Technologies
2019
Teaching of Green Analytical Chemistry (GAC) requires a not inconsiderable willingness on the part of the lecturer to familiarize himself with a relatively new field in analytical chemistry. Although there is much that can be derived from Green and Sustainable Chemistry, the GAC’s forward-looking perspectives in particular are independent approaches that must not be neglected. In the first chapter of this article, approaches are pursued “how (teachers) learn to learn,” ultimately based on a consensus on ethics, which allows dealing with people, society and the environment to become an interdisciplinary unit. The end of all this is a smart method of conflict management which provides solutio…
Baseline port surveys for invasive marine species in the Northeastern Baltic
2006
Marine ecosystems around the world are being transformed and degraded by non-indigenous species, which affect the structure and function of the ecosystem, causing major ecological and economic implications. Ships have been recognized as a major vector for the introduction of non-indigenous harmful organisms, carrying them in ballast water tanks and sediments. Activities to prevent and mitigate the impact of invasive alien species have to be based on cooperation. Financed by Phare Cross Border Co-operation Programme in the Baltic Sea Region (2005–2006) Latvia together with Estonia will focus on baseline port surveys for non-indigenous species in the north-eastern part of the Baltic Sea.
Top-covered unbaffled stirred tanks: experiments and numerical simulations
2015
In this work computational fluid dynamics was employed to predict the flow field of an unbaffled stirred tank from steady to turbulent conditions
Think tanks for a new generation of regional innovation policies
2021
Regional innovation policy, and related research, are being pressurized to transform by today’s grand societal challenges. Our paper acknowledges the efforts of authors in this field to address thi...
Oscillation dynamics of free vortex surface in uncovered unbaffled stirred vessels
2016
Abstract The main feature of unbaffled stirred tanks is the highly swirling liquid motion, which leads to the formation of a central vortex on the liquid free surface, when the vessel is operated without top-cover (Uncovered Unbaffled Stirred Tanks, UUST). One of the main drawbacks of such vessels, that limits their industrial applicability, is the possible onset of low-frequency sloshing of the free surface. In this work, original data on oscillation dynamics in UUST are presented. In particular, data focus on the oscillation amplitude as well as on their frequency. Data were obtained by means of a novel experimental technique based on digital image analysis. The effect of impeller geometr…
Mass transfer and hydrodynamic characteristics of unbaffled stirred bio-reactors: Influence of impeller design
2014
Abstract Unbaffled stirred tanks are increasingly recognized as a viable alternative to common baffled tanks for a range of processes where the presence of baffles is undesirable for some reason. For instance, in the case of shear sensitive cell cultivation (e.g. human cells), unbaffled tanks have been recently found to be able to provide sufficient mass transfer through the free surface vortex. As a consequence the need for bubble formation and subsequent bursting, along with relevant cells damage, is conveniently avoided. In this work the influence of impeller geometry on mass transfer performance and power demand of an unbaffled stirred vessel operating both in sub-critical conditions (t…
Unbaffled, Stirred Bioreactors for Animal Cell Cultivation
2017
One of the main features of animal cell bioreactors is that the cultured cells lack a strong membrane and are therefore more prone to shear damage. It is widely accepted that animal cell damage in aerated bioreactors is mainly related to burst bubbles at the air–liquid interface. A viable alternative to sparged bioreactors, aimed at minimizing cell damage, may be represented by uncovered, unbaffled, stirred tanks, which are able to provide sufficient mass transfer through the deep free surface vortex that takes place under agitation. As a consequence the need for bubble formation and subsequent bursting accompanied by cell damage is conveniently avoided. In this chapter, mass transfer perfo…
On vortex shape in unbaffled stirred vessels as measured by digital image analysis
2012
In this work, digital image analysis coupled with a suitable shadowgraphy-based technique is employed to investigate the shape of the free-surface vortex that forms in uncovered unbaffled tanks stirred by either a D=T/3 Lightnin A310 or a D=T/3 Rushton turbine. The technique is based on back-lighting the vessel and suitably averaging vortex images over time. Data obtained show that the two different impellers give rise to quite different vortex shapes. A novel 2-parameter model is proposed that successfully describes vortex shapes obtained with both impellers.
Un nuovo campionatore per la misura della perdita di suolo in parcelle attrezzate
2012
Le misure di perdita di suolo in parcelle attrezzate necessitano la conoscenza del peso del materiale eroso intercettato nella sezione terminale delle parcelle. Nell’area sperimentale di Sparacia attrezzata per la misura della perdita di suolo i deflussi torbidi prodotti in seguito ad un evento erosivo vengono convogliati mediante una grondaia posta a valle di ciascuna parcella all’interno di vasche di accumulo. Per misurare la frazione di materiale solido presente nel volume della sospensione raccolto in dette vasche, si propone l’utilizzo di un nuovo campionatore appositamente predisposto. Esso consiste in un cilindro di ottone, di noto diametro, dotato nella sezione terminale di una valv…
The emission saving related to the use of renewable energy sources: The case study of solar thermal collectors
2003
The employment of renewable energy sources can represent a useful way to reduce air emissions released by conventional ones. In this paper we describe the results of a Life Cycle Analysis performed upon one of the most world-wide diffused renewable technologies: the solar thermal collectors for warm sanitary water. Two domestic solar plants have been investigated: mono-familiar plant with a passive flat collector and a large solar plant with forced fluid circulation. The first step has been the evaluation of direct and indirect emissions related to the production and use of plants. The main emissions have been categorised in three of the most important indicators (Global Warming Potential, …