A Numerical Implementation of the Soret Effect in Drying Processes

Drying of porous media is strictly governed by heat and mass transfer. However, contrary to the definition that drying is simultaneous transport mechanisms of heat and mass, most past and current models either account for temperature or concentration gradient effects on drying. Even though the complexity of computations of these processes varies with area of application, in most cases, the Dufour and Soret effects are neglected. This leads to deviations and uncertainties on the assumptions and interpretations of these and other relevant effects on drying. This paper covers the theoretical methods to derive the coupled transfer effects. In addition, this work proposes and formulates relevant heat and mass transfer equations, as well as the governing equations for drying processes with Dufour and Soret effects. The application of a numerical approach to solve the equations allows for studying of the influence of these effects on the design and operation of dryers. It is shown that the Soret effect can be highly relevant on drying operations with dynamic heating operation. While for drying processes where the steady state drying process predominates, the effect is deemed negligible

News on demand considered useless: An explorative assessment of database news publication features

this paper describes the video scenario, details the interviews and their results, answers the main questions tentatively and finaLLy identifies what appears to be promising research direction

Uncertainty Analysis for Data-Driven Chance-Constrained Optimization

In this contribution our developed framework for data-driven chance-constrained optimization is extended with an uncertainty analysis module. The module quantifies uncertainty in output variables of rigorous simulations. It chooses the most accurate parametric continuous probability distribution model, minimizing deviation between model and data. A constraint is added to favour less complex models with a minimal required quality regarding the fit. The bases of the module are over 100 probability distribution models provided in the Scipy package in Python, a rigorous case-study is conducted selecting the four most relevant models for the application at hand. The applicability and precision of the uncertainty analyser module is investigated for an impact factor calculation in life cycle impact assessment to quantify the uncertainty in the results. Furthermore, the extended framework is verified with data from a first principle process model of a chloralkali plant, demonstrating the increased precision of the uncertainty description of the output variables, resulting in 25% increase in accuracy in the chance-constraint calculation.BMWi, 0350013A, ChemEFlex - Umsetzbarkeitsanalyse zur Lastflexibilisierung elektrochemischer Verfahren in der Industrie; Teilvorhaben: Modellierung der Chlor-Alkali-Elektrolyse sowie anderer Prozesse und deren Bewertung hinsichtlich Wirtschaftlichkeit und möglicher HemmnisseDFG, 414044773, Open Access Publizieren 2019 - 2020 / Technische Universität Berli

Designing social play through interpersonal touch:An annotated portfolio

We present five design cases as an annotated portfolio, exploring ways to design for intimate, interpersonal touch and social intimacy in interaction design. Five key qualities are elicited from the cases, including novel connotations sparking curiosity; providing an excuse to interact; unfolding internal complexity; social ambiguity; norm-bending intimacy. The work highlights novel interaction design approaches fostering social play, turning participants into performers of their own narratives

Skillnader i farmakologiska egenskaper mellan ketamins enantiomerer

Ketamin är ett anestetikum som används inom veterinärmedicinen på en rad djurslag. Den har sin huvudsakliga verkningsmekanism som icke-komepetetiv anatgonist på NMDA-receptorer och producerar en dissociativ anestesi. Ketamin förekommer som två enantiomerer, S-ketamin och R-ketamin, som på våra djurslag administreras gemensamt som ett racemat. Hos människa har det observerats skillnader i farmakokinetik och farmakodynamik mellan dessa isomerer. Senantiomeren har visat sig mer potent samt inducerar mindre orolighet och färre hallucinationer under uppvak. I den aktuella litteraturstudien görs en genomgång av det vetenskapliga underlag som berör skillnader i farmakologi för ketamins enantiomerer på våra husdjur. Dessutom görs ett försök att besvara frågan hurvida det är motiverat att använda en beredeningsform med endast S-enantiomeren istället för racemat ketamin. Författaren gör en presentation av ketamins kemiska struktur, basala fakta om stereospecificitet samt ketamins huvudsakliga verkningsmekanism, farmakokinetik och farmakodynamik. Där utöver berörs skillnader mellan enantiomererna gällande koncentrationer av modersubstans och metaboliter i plasma, systemiskt clearance, potens och tid för återhämtning. Djurslag så som häst, hund, katt, svin, gnagare och idisslare är inkluederade i materialet. Hos häst och hund verkar metabolismen av ketamin vara enantioselektiv men vid vilket metaboliskt steg verkar vara oklart. Det är möjligt att enantioselektivitet finns hos de enzymer som metaboliserar ketamin till dess aktiva metabolit norketamin. Det är också en möjlighet att det sker i hydroxylationen av norketamin, det vill säga nästkommande steg i ketamins metaboliska väg. Det finns i det presenterade materialet inga skillnader i systemiskt clearance mellan enantiomererna, bortsett från hos hund som sövts med halotan. Där misstänks dock läkemedelsinterkationer vara en faktor som påverkar. Bland våra husdjur, likt för människa, har S-ketamin generellt en högre potens än R-enantiomeren och racematet. Det är troligt att skillnaden kommer sig av en högre affinitet för NMDA-receptorerna hos S-enantiomeren. I litteraturen finns även beskrivet att anestesi med S-ketamin efterföljs av ett snabbare uppvak på hund. Detta gäller även häst, som reser sig snabbare eller med bättre koordination efter avslutad anestesi. Det skall dock poängteras att studiepopulationerna för de presenterade studierna har genomgående varit små. Det är därför svårt att dra slutsatser utifrån endast det presenterade materialet. Avslutningsvis kan därmed sägas att trots vissa skillnader enantiomererna emellan är det, baserat på den här litteraturstudien, inte motiverat att frångå veterinärmedicinsk praxis och administrera S-enantiomeren isolerad istället för i racemat form.Ketamine is an anestethic drug used in veterinary medicine on a variety of species. It’s main mechanism of action is as a non-competitive antagonist on the NMDA-receptors and produces a dissociative anesthesia. Ketamine excists as two enantiomers, S-ketamine and R-ketamine, that are administered together as a racemic to our domestic animals. In humans differences in pharmacokinetics and pharmacodynamics between these two isomers have been observed. The S-enantiomorph has been shown to be more potent and provide less agitation and hallucinations during emergence from anesthesia in humans. The present litterature review presents available scientific litterature that describes differences in pharmacology between the enantimorphs on our domesticated animals. Furthermore, the author has attempted to adress the question on whether usage of the isolated S-enantiomer instead of racemic ketamine would be motivated on these species. The review presents the chemical structure of ketamine, the basics of stereospecificity and ketamines mechanism of action, pharmacokinetics and pharmacodynamics. It addresses differences in concentration of ketamin and its active metabolite norketamine in plasma, systemic clearance, potency and time of recovery in species such as equines, canines, felines, porcine, rodents and ruminants. For equines and canines, the metabolism seems to be enantioselective although at what metabolic step is inconclusive. It could be that enantioselectivity occurs in the enzymes that metabolizes ketamin to norketamine. There is also the possibility that it occus in the hydroxylation of norketamin, which is the following step in ketamines metabolic pathway. In the presented material there are no differences in systemic clearance between the two enantiomers, except for canines sedated with halothane. Here druginteractions seems to be a contributing factor. In animals, much like in humans, the S-enantiomer is generally more potent than the R-enantiomer and the racemic. It is possible this is a result of S-ketamine having a higher affinitiy for the NMDA-receptors. Following anesthesia with S-ketamine the time of recovery is shorter in canines. This has been observed in equines as well, who stand up faster or with better coordination. However, the study populations in the presented literature has been overall small. Drawing conclusions from the presented material only is therefore difficult. In conclusion, despite suggested differences between ketamine enantiomorhps it would not be motivated to break clinical protocol and administer the isolated S-enantiomer instead of racemic ketamine based on this literature study alone

A Longer Interstimulus Interval Yields Better Learning in Adults and Young Adolescents

Eyeblink conditioning is one of the most popular experimental paradigms for studying the neural mechanisms underlying learning and memory. A key parameter in eyeblink conditioning is the interstimulus interval (ISI), the time between the onset of the conditional stimulus (CS) and the onset of the unconditional stimulus (US). Though previous studies have examined how the ISI affects learning there is no clear consensus concerning which ISI is most effective and different researchers use different ISIs. Importantly, the brain undergoes changes throughout life with significant cerebellar growth in adolescents, which could mean that different ISIs might be called for in children, adolescents and adults. Moreover, the fact that animals are often trained with a shorter ISI than humans make direct comparisons problematic. In this study, we compared eyeblink conditioning in young adolescents aged 10–15 and adults using one short ISI (300 ms) and one long ISI (500 ms). The results demonstrate that young adolescents and adults produce a higher percentage of CRs when they are trained with a 500 ms ISI compared to a 300 ms ISI. The results also show that learning is better in the adults, especially for the shorter ISI