Air Filtration in HVAC Systems

The Guidebook presents the theory of air filtration with some basic principles of the physics of pollutants and their effects on indoor quality. The main focus is on practical design, installation and operation of filters in air handling systems. It is intended for the use of designers, manufacturers, installers, and building owners. With its theory, practical solutions and illustrations it is also an excellent textbook for the vocational training of various experts in building services engineering

Valosaasteen ekologiset vaikutukset:keinotekoisen valaistuksen vaikutukset hyönteisten käyttäytymiseen

Tiivistelmä. Keinotekoinen valaistus on lisääntynyt viime vuosisadan aikana niin tilallisesti ja ajallisesti kuin laadullisesti, uusimpien valaisinteknologioiden, kuten ledien, tuottaessa entistä laajemmin eri aallonpituuksia. Valosaasteesta eli haitallisesta keinotekoisesta valosta on tullut yksi yleisimmistä ja nopeimmin lisääntyvistä ympäristömuutoksen muodoista. Valosaaste ulottuu lähes kaikkialle maapallolla, niin maa- kuin vesiekosysteemeihin. Elämä maapallolla on kehittynyt auringon ja tähtien valon sekä kuusta heijastuvan auringonvalon, luonnonvalolle ominaisten voimakkuuksien ja spektrin sekä valon ja pimeyden jaksottaisuuksien vaikutuksessa. Valo ja pimeys toimivat luonnossa resursseina ja valo tiedonlähteenä ympäristöstä, säädellen eliöiden fysiologiaa ja biologisia rytmejä sekä vaikuttaen eläinten visuaaliseen havaitsemiskykyyn ja yöaikaiseen suunnistamiseen. Keinotekoinen valo on historiallisesti uusi ilmiö, joka eroaa ominaisuuksiltaan luonnonvalosta ja häiritsee luonnollisia valon ja pimeyden vaihteluita. Keinotekoisella valolla on merkittäviä biologisia ja ekologisia vaikutuksia luonnonvaraisiin eliöihin, ulottuen yksilöistä ekosysteemien tasolle. Yöaikainen keinotekoinen valo vaikuttaa hyönteisten käyttäytymiseen muuttamalla niiden aktiivisuutta ja suunnistamista, vetämällä hyönteisiä puoleensa sekä häiritsemällä bioluminesoivien hyönteisten viestintää ja lisääntymistä. Muutokset hyönteisten käyttäytymisessä voivat vaikuttaa edelleen lajien väliseen vuorovaikutukseen, kuten peto-saalis-vuorovaikutukseen ja hyönteispölytykseen. Valosaasteella voi olla merkittäviä ympäristövaikutuksia, kuten elinympäristöjen pirstoutuminen ja luonnon monimuotoisuuden heikkeneminen. Valosaasteen uskotaan lisäksi olevan yksi hyönteisten runsauden maailmanlaajuisen vähenemisen taustalla vaikuttavista tekijöistä. Hyönteiset ovat vallitseva eliöryhmä maailmassa ja merkittävä osa ekosysteemejä, minkä vuoksi hyönteisten vasteet ympäristömuutoksiin voivat vaikuttaa dramaattisesti ekosysteemien rakenteeseen ja toimintaan, sekä ihmisten kannalta merkittäviin ekosysteemipalveluihin

Burst analysis tool for developing neuronal networks exhibiting highly varying action potential dynamics

In this paper we propose a firing statistics based neuronal network burst detection algorithm for neuronal networks exhibiting highly variable action potential dynamics. Electrical activity of neuronal networks is generally analyzed by the occurrences of spikes and bursts both in time and space. Commonly accepted analysis tools employ burst detection algorithms based on predefined criteria. However, maturing neuronal networks, such as those originating from human embryonic stem cells (hESCs), exhibit highly variable network structure and time-varying dynamics. To explore the developing burst/spike activities of such networks, we propose a burst detection algorithm which utilizes the firing statistics based on interspike interval (ISI) histograms. Moreover, the algorithm calculates ISI thresholds for burst spikes as well as for pre-burst spikes and burst tails by evaluating the cumulative moving average (CMA) and skewness of the ISI histogram. Because of the adaptive nature of the proposed algorithm, its analysis power is not limited by the type of neuronal cell network at hand. We demonstrate the functionality of our algorithm with two different types of microelectrode array (MEA) data recorded from spontaneously active hESC-derived neuronal cell networks. The same data was also analyzed by two commonly employed burst detection algorithms and the differences in burst detection results are illustrated. The results demonstrate that our method is both adaptive to the firing statistics of the network and yields successful burst detection from the data. In conclusion, the proposed method is a potential tool for analyzing of hESC-derived neuronal cell networks and thus can be utilized in studies aiming to understand the development and functioning of human neuronal networks and as an analysis tool for in vitro drug screening and neurotoxicity assays

Continuous Team Semantics

Peer reviewe

Continuous Team Semantics

We study logics with team semantics in computable metric spaces. We show how to define approximate versions of the usual independence/dependence atoms. For restricted classes of formulae, we show that we can assume w.l.o.g.~that teams are closed sets. This then allows us to import techniques from computable analysis to study the complexity of formula satisfaction and model checking

Computational Study of Hydrogen Shifts and Ring-Opening Mechanisms in alpha-Pinene Ozonolysis Products

Autoxidation by: sequential peroxy radical hydrogen shifts (H-shifts) and O-2 additions has recently emerged as a promising mechanism for the rapid formation of highly oxidized, low-Volatility organic Compounds in the. atmosphere: A kg prerequisite for auto)ddation is that the H-shifts of the initial peroxy radicals formed by, e.g., OH or O-3 oxidation are fast enough to compete with bimolecular sink reactions. In most atmospheric conditions, these restrict the lifetime Of peroxy.radicals to be on the order of seconds. We have systematically investigated all potentially important (nonmethyl, sterically unhindered) H-shifts of all four peroxy radicals formed in the ozonolysis of alpha-pinene using density functional (omega B97XD) and coupled cluster [CCSD(T)-F12] theory. In contrast to the related but chemically simpler tyclohexene ozonolysis system, none of the calculated li-shifts have rate constants above 1 s(-1) at 298 K, and most are below 0.01 s(-1). The law rate constants are connected to the presence of the' strained tyclobutyi sing in the alpha-pinene-derived peroxy radicals, which hinders H-shifts both from and across the ring. For autoxidation to yield the experimentally observed highly oxidized products in the alpha-pinene ozonolysis system, additional ring-opening reaction mechanisms breaking the cyclobutyl ring are therefore needed. We further investigate possible uni- and bimolecular pathways for,opening the cydobutyl ring in, the alpha-pinene ozonolysis system.Peer reviewe

The undatables : Quantifying uncertainty in a highly expanded Late Glacial-Holocene sediment sequence recovered from the deepest Baltic Sea basin-IODP Site M0063

Laminated, organic-rich silts and clays with high dissolved gas content characterize sediments at IODP Site M0063 in the Landsort Deep, which at 459 m is the deepest basin in the Baltic Sea. Cores recovered from Hole M0063A experienced significant expansion as gas was released during the recovery process, resulting in high sediment loss. Therefore, during operations at subsequent holes, penetration was reduced to 2 m per 3.3 m core, permitting expansion into 1.3 m of initially empty liner. Fully filled liners were recovered from Holes B through E, indicating that the length of recovered intervals exceeded the penetrated distance by a factor of > 1.5. A typical down-core logarithmic trend in gamma density profiles, with anomalously low-density values within the upper similar to 1 m of each core, suggests that expansion primarily occurred in this upper interval. Thus, we suggest that a simple linear correction is inappropriate. This interpretation is supported by anisotropy of magnetic susceptibility data that indicate vertical stretching in the upper similar to 1.5 m of expanded cores. Based on the mean gamma density profiles of cores from Holes M0063C and D, we obtain an expansion function that is used to adjust the depth of each core to conform to its known penetration. The variance in these profiles allows for quantification of uncertainty in the adjusted depth scale. Using a number of bulk C-14 dates, we explore how the presence of multiple carbon source pathways leads to poorly constrained radiocarbon reservoir age variability that significantly affects age and sedimentation rate calculations.Peer reviewe

3D Scaffolds of Polycaprolactone/Copper-Doped Bioactive Glass: Architecture Engineering with Additive Manufacturing and CellularAssessments in a Coculture of Bone Marrow Stem Cells and Endothelial Cells

The local delivery of Cu2+ from copper-doped bioactive glass (Cu-BaG) was combined with 3D printing of polycaprolactone (PCL) scaffolds for its potent angiogenic effect in bone tissue engineering. PCL and Cu-BaG were, respectively, dissolved and dispersed in acetone to formulate a moderately homogeneous ink. The PCL/Cu-BaG scaffolds were fabricated via direct ink writing into a cold ethanol bath. The architecture of the printed scaffolds, including strut diameter, strut spacing, and porosity, were investigated and characterized. The PCL/Cu-BaG scaffolds showed a Cu-BaG content-dependent mechanical property, as the compressive Young\u27s modulus ranged from 7 to 13 MPa at an apparent porosity of 60%. The ion dissolution behavior in simulated body fluid was evaluated, and the hydroxyapatite-like precipitation on the strut surface was confirmed. Furthermore, the cytocompatibility of the PCL/Cu-BaG scaffolds was assessed in human bone marrow stem cell (hBMSC) culture, and a dose-dependent cytotoxicity of Cu2+ was observed. Here, the PCL/BaG scaffold induced the higher expression of late osteogenic genes OSTEOCALCIN and DLX5 in comparison to the PCL scaffold. The doping of Cu2+ in BaG elicited higher expression of the early osteogenic marker gene RUNX2a but decreased the expression of late osteogenic marker genes OSTEOCALCIN and DLX5 in comparison to the PCL/BaG scaffold, demonstrating the suppressing effect of Cu2+ on osteogenic differentiation of hBMSCs. In a coculture of hBMSCs and human umbilical vein endothelial cells, both the PCL/BaG and PCL/Cu-BaG scaffolds stimulated the formation of a denser tubule network, compared to the PCL scaffold. Meanwhile, only slightly higher gene expression of vWF was observed with the PCL/Cu-BaG scaffold than with the PCL/BaG scaffold, indicating the potent angiogenic effect of the released Cu2+