Effect of water velocity on the uptake of polychlorinatedd biphenyls (PCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers: an assessment of the efficiency of performance reference compounds (PRCs) in river-like flow conditions

One aim of this study is to determine the impact of water velocity on the uptake of indicator polychlorinated biphenyls (iPCBs) by silicone rubber (SR) and low-density polyethylene (LDPE) passive samplers. A second aim is to assess the efficiency of performance reference compounds (PRCs) to correct for the impact of water velocity. SR and LDPE samplers were spiked with 11 or 12 PRCs and exposed for 6 weeks to four different velocities (in the range of 1.6 to 37.7 cm s−1) in river-like flow conditions using a channel system supplied with river water. A relationship between velocity and the uptakewas found for each iPCB and enables to determine expected changes in the uptake due to velocity variations. For both samplers, velocity increases from 2 to 10 cm s−1, 30 cm s−1 (interpolated data) and 100 cm s−1 (extrapolated data) lead to increases of the uptake which do not exceed a factor of 2, 3 and 4.5, respectively. Results also showed that the influence of velocity decreased with increasing the octanol-water coefficient partition (log Kow) of iPCBs when SR is used whereas the opposite effect was observed for LDPE. Time-weighted average (TWA) concentrations of iPCBs in water were calculated from iPCB uptake and PRC release. These calculations were performed using either a single PRC or all the PRCs. The efficiency of PRCs to correct the impact of velocity was assessed by comparing the TWA concentrations obtained at the four tested velocities. For SR, a good agreement was found among the four TWA concentrations with both methods (average RSD b 10%). Also for LDPE, PRCs offered a good correction of the impact of water velocity (average RSD of about 10 to 20%). These results contribute to the process of acceptance of passive sampling in routine regulatory monitoring programs.

Extending the canopy flow model for natural, highly flexible macrophyte canopies

Flow structures above vegetation canopies have received much attention within terrestrial and aquatic literature. This research has led to a good process understanding of mean and turbulent canopy flow structure. However, much of this research has focused on rigid or semi-rigid vegetation with relatively simple morphology. Aquatic macrophytes differ from this form, exhibiting more complex morphologies, predominantly horizontal posture in the flow and a different force balance. While some recent studies have investigated such canopies, there is still the need to examine the relevance and applicability of general canopy layer theory to these types of vegetation. Here, we report on a range of numerical experiments, using both semi-rigid and highly flexible canopies. The results for the semi-rigid canopies support existing canopy layer theory. However, for the highly flexible vegetation, the flow pattern is much more complex and suggests that a new canopy model may be required.

Using the optical flow to implement a relative virtual mouse controlled by head movements

The following paper introduces the work conducted to create a relative virtual mouse based on the interpretation of head movements and face gesture through a low cost camera and the optical flow of the images. This virtual device is designed specifically as an alternative non-contact pointer for people with mobility impairments in the upper extremities and reduced head control. The proposed virtual device was compared with a conventional mouse, a touchpad and a digital joystick. Validation results show performances close to a digital joystick but far away from a conventional mouse.

Climate and human forcing of Alpine river flow

River flow in Alpine environments is likely to be highly sensitive to climate change because of the effects of warming upon snow and ice, and hence the intra-annual distribution of river runoff. It is also likely to be influenced strongly by human impacts both upon hydrology (e.g. flow abstraction) and river regulation. This paper compares the river flow and sediment flux of two Alpine drainage basins over the last 5 to 7 decades, one that is largely unimpacted by human activities, one strongly impacted by flow abstraction for hydroelectricity. The analysis shows that both river flow and sediment transport capacity are strongly dependent upon the effects of temperature and precipitation availability upon snow accumulation. As the latter tends to increase annual maximum flows, and given the non-linear form of most sediment transport laws, current warming trends may lead to increased sedimentation in Alpine rivers. However, extension to a system impacted upon by flow abstraction reveals the dominant effect that human activity can have upon river sedimentation but also how human response to sediment management has co-evolved with climate forcing to make disentangling the two very difficult.

Flow resistance equations for mountain rivers

Three models of flow resistance (a Keulegan-type logarithmic law and two models developed for large-scale roughness conditions: the full logarithmic law and a model based on an inflectional velocity profile) were calibrated, validated and compared using an extensive database (N = 1,533) from rivers and flumes, representative of a wide hydraulic and geomorphologic range in the field of gravel-bed and mountain channels. It is preferable to apply the model based on an inflectional velocity profile in the relative submergence (y/d90) interval between 0.5 and 15, while the full logarithmic law is preferable for values below 0.5. For high relative submergence, above 15, either the logarithmic law or the full logarithmic law can be applied. The models fitted to the coarser percentiles are preferable to those fitted to the median diameter, owing to the higher explanatory power achieved by setting a model, the smaller difference in the goodness-of-fit between the different models and the lower influence of the origin of the data (river or flume).

Long-term continuous-flow left ventricular assist devices (LVAD) as bridge to heart transplantation.

Heart transplantation (HTx) is the treatment of choice for end-stage heart failure but the limited availability of heart's donors still represents a major issue. So long-term mechanical circulatory support (MCS) has been proposed as an alternative treatment option to assist patients scheduled on HTx waiting list bridging them for a variable time period to cardiac transplantation-the so-called bridge-to-transplantation (BTT) strategy. Nowadays approximately 90% of patients being considered for MCS receive a left ventricular assist device (LVAD). In fact, LVAD experienced several improvements in the last decade and the predominance of continuous-flow over pulsatile-flow technology has been evident since 2008. The aim of the present report is to give an overview of continuous-flow LVAD utilization in the specific setting of the BTT strategy taking into consideration the most representative articles of the scientific literature and focusing the attention on the evolution, clinical outcomes, relevant implications on the HTx strategy and future perspectives of the continuous-flow LVAD technology.

Disaster recovery of business critical 3-tiered ERP applications: Disaster Recovery of Nokia Groups SAP R/3

Nykyaikaisessa liiketoimintaympäristössä yritysten kriittisiksi resursseiksi ovat muodostuneet liiketoimintaa tukevat tietojärjestelmät. Mahdollisuus hyödyntää näitä resursseja riippuu ko. liiketoiminnalle kriittisten järjestelmien luotettavuudesta ja hyödynnettävien sovellusten saatavuudesta. Eräs tilanne jossa järjestelmien kyky tukea todellisia liiketoimintaprosesseja vaarantuu on katastrofi. Vaikutukseltaan katastrofi voi olla paikallinen tai kattaa laajojakin alueita. Eri tyyppisiin katastrofeihin on varauduttava niiden edellyttämin tavoin. Eräs kriittisten tietojärjestelmien arkkitehtuuriin vaikuttanut trendi 90-luvulla on ollut client/server lähestymistapa. Client/server paradigman mukaan sovellus jaetaan tasoihin siten että esitys-, sovellus- ja tietokantakerrokset voidaan erottaa fyysisesti toisistaan näiden silti muodostaessa loogisesti yhtenäisen kokonaisuuden. Liiketoiminnan näkökulmasta 90- luvun mullistavia IT-uutuuksia olivat toiminnanohjausjärjestelmät, joiden avulla oli mahdollista hallita koko tuotantoketjua ja muita prosessikokonaisuuksia lähes reaaliajassa. Monikerroksisten toiminnanohjausjärjestelmien luotettavuus on osoittautunut haastavavaksi sillä kaikkien kerrosten suojaaminen kaikilta mahdollisilta katastrofeilta täydellisesti on nykyisellä teknologialla mahdotonta. Kompromissien tekemiseksi on oltava selvillä kunkin menetetyn prosessin aiheuttamista taloudellisista ja liiketoiminnallisista vaikutuksista. Tämän vuoksi juuri toiminnanohjausjärjestelmät ovat mielenkiintoisia, vaikuttavathan ne liiketoimintaprosesseihin läpi koko yrityksen prosessiketjun. Monikerroksisten client/server arkkitehtuuriin pohjautuvien toiminnanohjausjärjestelmien suojaamisessa katastrofeilta onkin sovellettava useita tekniikoita ja teknologioita, ja yhdistettävä kokonaisuus prosessikehykseen. Näin voidaan luoda suunnitelmallinen osa IT strategiaa, joka ottaa kantaa liiketoiminnan jatkuvuuteen katastrofitilanteessa ja mahdollistaa nopean ja täydellisen palautumisen kaikissa olosuhteissa.

Comparison of Compound Lean Nozzles and Controlled Flow Nozzles at Off-Design

Turbokoneet ja etenkin höyryturbiinit ovat usein suunniteltu ja optimoitu toimimaan tietyssä toimintapisteessä jossa häviöt on minimoitu ja hyötysuhde maksimoitu. Joissakin tapauksissa on kuitenkin tarpeellista käyttää turbiinia toimintapisteen ulkopuolella. Tällöin turbiinin läpi virtaava massavirta muuttuu ja yleensä heikentää hyötysuhdetta. Turbokoneiden suorituskykyä voidaan parantaa käyttämällä kolmidimensionaalisesti muotoiltuja siipiä. Työssä on vertailtu laskennallisesti kahta kohtuullisesti muotoiltua suutinta (Compound lean ja Controlled flow) niiden suunnitellun toimintapisteen ulkopuolella. Kolmas suutin, ilman kolmidimensionaalista muotoilua on mukana vertailukohteena. Suutinten suorituskykyä tutkitaan laskennallisen virtausmekaniikan avulla olosuhteissa, jotka ovat toimintapisteen ulkopuolella. Virtauksen muutoksia tutkitaan kokonaispainehäviön, isentrooppisen hyötysuhteen ja virtauspinnan yhdenmukaisuuden avulla. Virtauspintoja verrataan ulosvirtauskulman, massavirran ja toisiovirtausvektoreiden jakauman avulla. Erot suutinten suorituskykyvyssä korostavat ylikuormalla. Kun massavirran arvoa on kohotettu eniten, Compound lean suuttimilla hyötysuhde laskee Controlled flow suuttimeen verrattuna vähemmän. Alikuormalla, kun massavirran arvoa lasketaan, erot suuttimien suorituskyvyssä pienenevät ja tutkittujen suuttimien ulosvirtaus on samankaltainen.

Implantació de SAP ERP a una empresa de laboratoris

Projecte d'implantació de SAP ERP en una empresa.

SAP R/3 -toimimianohjausjärjestelmän käytettävyyden parantaminen metsäteollisuusyrityksessä

Työn tavoitteena on parantaa SAP R/3-järjestelmän käytettävyyttä muutoksenhallintaprosessia mallintamalla. Työn alussa selkeytetään järjestelmän käytön nykytilaa yrityksessä sekä käyttäjien vaatimia parannuskohteita. Työn teoriaosassa käsitellään asiakasnäkökulmasta prosessien kehittämisen sekä niiden mallintamisen teoriaa. Teoriaosassa haetaan vastauksia järjestelmiin liittyviin kysymyksiin: - Kuinka selkeytetään käyttöönottoa sekä hyödynnetään toiminnan prosessilähtöistä kehittämistä? - Kuinka asiakastarpeita kartoittamalla huomioidaan käyttäjien tulevat taipeet? - Miten prosessimallintaminen lisää käyttäjien luottamusta ja yrityksen kilpailukykyä? Soveltavassa osassa tutkitaan vika- ja pienkehityspyyntöjen hallintaa ARIS-mallinnuksen avulla. Toimintoketjun avulla luodaan M-real-konsemissa käyttäjien ja palveluntarjoajan yhteinen toimintamalli. Prosessin omistajuus, käyttäjien liittymäpinta sekä toiminnan organisointi huomioidaan kaikkien osapuolten kesken

Gene flow and gene flux shape evolutionary patterns of variation in Drosophila subobscura

Gene flow (defined as allele exchange between populations) and gene flux (defined as allele exchange during meiosis in heterokaryotypic females) are important factors decreasing genetic differentiation between populations and inversions. Many chromosomal inversions are under strong selection and their role in recombination reduction enhances the maintenance of their genetic distinctness. Here we analyze levels and patterns of nucleotide diversity, selection and demographic history, using 37 individuals of Drosophila subobscura from Mount Parnes (Greece) and Barcelona (Spain). Our sampling focused on two frequent O-chromosome arrangements that differ by two overlapping inversions (OST and O3+4), which are differentially adapted to the environment as observed by their opposing latitudinal clines in inversion frequencies. The six analyzed genes (Pif1A, Abi, Sqd, Yrt, Atpa and Fmr1) were selected for their location across the O-chromosome and their implication in thermal adaptation. Despite the extensive gene flux detected outside the inverted region, significant genetic differentiation between both arrangements was found inside it. However, high levels of gene flow were detected for all six genes when comparing the same arrangement among populations. These results suggest that the adaptive value of inversions is maintained, regardless of the lack of genetic differentiation within arrangements from different populations, and thus favors the Local Adaptation hypothesis over the Coadapted Genome hypothesis as the basis of the selection acting on inversions in these populations.