Verktyg för akustisk design

Behovet av att kontrollera ljud blir viktigare när våra städer förtätas. Utmaningen ligger i att skapa en fungerande stadsmiljö med hänsyn till bland annat ändamål, upplevelsevärden och hälsa. Stadens ljud handlar därför om mer än bara buller – det kan handla om att introducera önskade ljud likväl som att reducera oönskade. I detta Movium Fakta presenterar de två skribenterna ”blå-gröna” verktyg för akustiska designåtgärder, reder ut frågetecken och missförstånd kring ljudlandskap samt ger exempel på genomförda projekt

Energy efficient fish attraction

Fish migration past a hydro power plant (HPP) requires not only flow in the actual fish passage (e.g. fish ladder) but also sufficient water to attract the fish to the entrance. Such attraction water is typically created by spilling water of the order of 10 m3/s, and there are potential savings if the amount of water can be reduced without loss of functionality. The possibility to use ejectors (jet pumps) to pump water from the area downstream of the HPP into the fish passage has been investigated with physical model tests and numerical modelling (CFD). The ambition has been to make use of fairly simple geometries without changing the layout of the suggested fish ladder, and a solution in which the ejectors are located in a separate channel parallel to the fish ladder has been evaluated. The results show that the required spill can be reduced to 1/3 despite the low head (7 m) of the considered HPP, and the savings will be even larger in HPPs with higher head. More energy efficient ways to attract fish can be obtained if the jets are positioned within the actual fish way, but a prerequisite for such solution is that the fish is not intimidated by the jets. Another interesting option to evaluate is the possibility to guide the fish to the fish ladder entrance by an array of individual jets positioned in the river. To investigate these ideas tests with live fish are scheduled during second half of 2018

Evaluation of Guiding Device for Downstream Fish Migration with in-Field Particle Tracking Velocimetry and CFD

The performance of a fish guiding device located just upstream a hydropower plant is scrutinized. The device is designed to redirect surface orientated down-stream migrating fish (smolts) away from the turbines towards a spillway that act as a relatively safe fishway. Particles are added up-stream the device and the fraction particles going to the spillway is measured. A two-frame Particle Tracking Velocimetry algorithm is used to derive the velocity field of the water. The experimental results are compared to simulations with CFD. If the smolts move passively as the particles used in the study the guiding device works very well and some modifications may optimize its performance. In-field Particle Tracking Velocimetry is a suitable technique for the current case and the results compare well with numerical simulations

Laxens nedströmsvandring mot fiskavledare till Stornorrfors fisktrappa i Umeälvens nedre del

Rapporten sammanfattar våra arbeten med målsättning att skapa en fungerande fiskavledning för nedströmsvandrande fisk i vid Stornorrfors kraftverkskomplex i Umeälven. Rapporten visar även på verksamheter som nyttjats vid planering och utvärdering av gjorda åtgärder. Åtgärder i fisktrappan, fiskavledare och utrustning för registrering av PIT-tags har möjliggjorts genom finansiering av Europeiska Fiskefonden, Havs- och Vattenmyndigheten, Umeå kommun, Vattenfall och SLU. Arbetena har genomförts som två pilotprojekt (3b Nedströmsvandring Stornorrfors 2009-2010 och 3b2 Nedströmsvandring Stornorrfors 2011-2013). Vilda lax- och öring bestånd i våra älvar är viktiga naturresurser för människan och ekosystemet. Vindelälvens naturliga fiskproduktion av lax- och havsöring ungar är betydande för Östersjöns laxbestånd. De senaste åren har mer än 10 000 lax årligen vandrat uppströms för lek i älven. Många föräldrafiskar (Kelt, vraklax, besa, mm) överlever leken och vill vandra tillbaka till havet. Laxens naturliga avkomma, smolten, strävar också att ta sig till födoområdena i Östersjön. I flödesreglerade vattendrag som Umeälven med sitt unika laxbestånd i biflödet Vindelälven finns problem med dödlighet då kelt och smolt på sin nedströmsvandring ska passera Stornorrfors kraftverk. I Umeälvens nedre del färdigställdes en ny fisktrappa i Norrfors 2010 som utrustats med en ”fiskavledare”. Projektets mål var att bygga och ansluta fiskavledaren till nya fisktrappan och utvärdera dess funktion/effektivitet. Det mätbara målet för den planerade anläggningen vid Stornorrfors utskovsdamm sattes till att 75 % av den utvandrande vilda smolten och minst 50 % av den övervintrande kelten skulle avledas till nya fisktrappan för vidare vandring till havet. Detta mål kunde inte uppnås. Den nya fisktrappan skulle alltså fungera som ett klassiskt "omlöp" förbi kraftverket. Vild smolt har märkts med Passiva Integrerade Transpondrar (PIT) eller aktiva Radiomärken (RT) och senare skannats vid passage i fisktrappsområdet (PIT + RT-märkt fisk) eller vid intaget till Stornorrfors kraftverk (RT-märkt fisk). SLU’s utvärdering av ledarmens funktion och fiskens vandring nedströms har visat att fiskavledarens funktion varit mycket svår att kontrollera då ledarmen inte fungerat som tänkt i den tuffa strömmiljön ovan fisktrappans område mellan 2010-2012. Avledningseffektiviteten kunde med visst förtroende endast värderas vid 2013 års försök med PIT-märkt fisk (n=1749 fiskar) som släpptes dagligen efter fångst i Vindelälven (INDEX Spöland) när flödet var < 800 m3/s i älven. Den totala avledningseffektiviteten visade sig vara 4,5 %. Begränsande för utvärderingen har varit att stora grupper smolt periodvis inte kunnat fångas och märkas på grund av höga flöden i Vindelälven. Effektiviteten i ledarmen har varierat mellan 0 och 100 % under säsongen. Väldigt få Kelt av lax kunde avledas. Höga turbinflöden tycks haft en positiv inverkan på ledarmens funktion. Smoltens passage nedströms i och genom fisktrappan verkar fungera utan större problem. Via PIT-märkt fisk och videofilmning i flera delförsök kunde vi visa på en lyckad genomfart där laxsmolten passerar fisktrappan inom några timmar till 2-3 dagar. Flödesmätning och modellering av strömningen runt fiskavledarens område mot ingången till nya fisktrappan visar att ledarmen borde ökas till ca 150 meters längd istället för dagens 110 meter. Flödesmodelleringar visar då att en större del av ytströmmen kan styras in mot fisktrappans ingång. Försöken med fångst, märkning, utsättning och återfångst har fungerat bra och PIT-märkningstekniken bedöms överlägsen andra märktekniker för detektering av fisk om detekteringsutrustning installerats. Detta kan utvecklas vidare inom ramen för indexälvsverksamheten (ICES-DCF) som nu bedrivs i Vindelälven. Sverige bör fortsätta att ta ansvar för den här typen av utveckling då det finns samordningsvinster mellan indexvattendrag, fiskavledning och utvärdering av fisktrappan för lekvandrande fisk. Lyckas man avleda den naturligt producerade avkomman av lax och öring i reglerade vattendrag med unika bestånd finns mycket att vinna för att etablera långsiktigt hållbara bestånd av vandringsfisk. Den typ av fiskavledare som nu prövats har tidigare inte prövats i Europa varför detta pilotprojekt är unikt. Arbetet som nu avslutats har varit ett samverkansprojekt mellan Europeiska Fiskerifonden, Havs- och Vattenmyndigheten, vattenkraftsägare, lokala och nationella fiskeriadministratörer samt forskare i fiskbiologi och hydraulik

Challenges for 10 nm MOSFET process integration, Journal of Telecommunications and Information Technology, 2007, nr 2

An overview of critical integration issues for future generation MOSFETs towards 10 nm gate length is presented. Novel materials and innovative structures are discussed. The need for high-k gate dielectrics and a metal gate electrode is discussed. Different techniques for strain-enhanced mobility are discussed. As an example, ultra thin body SOI devices with high mobility SiGe channels are demonstrated

Malmbanan Diaries

This booklet is a report for a case study visit during four day field trip, a group of nine PhD students and their supervisors – all part of the National Research School for Architecture and Planning in the Urban Landscape, APULA – set out to explore what may be considered the outback of Western Europe’s conurbations, the transnational region of Kiruna -Narvik.Both “remote” and “resourceful”, “threatened” and “thriving” (equally relative notions), this region seemed to offer possibilities to reflect upon many of the current tendencies influencing contemporary planning practice and research

Clinical use of cerebral oximetry in extremely preterm infants is feasible

Introduction: The research programme Safeguarding the Brains of our smallest Children (SafeBoosC) aims to test the benefits and harms of cerebral near-infrared spectroscopy (NIRS) oximetry in infants born before 28 weeks of gestation. In a phase II trial, infants will be randomised to visible cerebral NIRS oximetry with pre-specified treatment guidelines compared to standard care with blinded NIRS-monitoring. The primary outcome is duration multiplied with the extent outside the normal range of regional tissue oxygen saturation of haemoglobin (rStO2) of 55 to 85% in percentage hours (burden). This study was a pilot of the Visible ­Oximetry Group. Material and methods: This was an observational study including ten infants. Results: The median gestational age was 26 weeks + three days, and the median start-up time was 133 minutes after delivery. The median recording time was 69.7 hours, mean rStO2 was 64.2 ± 4.5%, median burden of hyper- and hy­poxia was 30.3% hours (range 2.8-112.3). Clinical staff responded to an out of range value 29 times – only once to values above 85%. In comparison, there were 83 periods of more than ten minutes with an rStO2 below 55% and four episodes with an rStO2 above 85%. These periods accounted for 72% of the total hypoxia burden. A total of 18 of the 29 interventions were adjustments of FiO2 which in 13 of the 18 times resulted in an out-of-range SpO2. Two infants suffered second-degree burns from the sensor. Five infants died. In all cases, this was unrelated to NIRS monitoring and treatment. Conclusion: The intervention of early cerebral NIRS monitoring proved feasible, but prolonged periods of hypoxia went untreated. Thus, a revision of the treatment guideline and an alarm system is required

A phase II randomized clinical trial on cerebral near-infrared spectroscopy plus a treatment guideline versus treatment as usual for extremely preterm infants during the first three days of life (SafeBoosC): study protocol for a randomized controlled trial

Background: Every year in Europe about 25,000 infants are born extremely preterm. These infants have a 20% mortality rate, and 25% of survivors have severe long-term cerebral impairment. Preventative measures are key to reduce mortality and morbidity in an extremely preterm population. The primary objective of the SafeBoosC phase II trial is to examine if it is possible to stabilize the cerebral oxygenation of extremely preterm infants during the first 72 hours of life through the application of cerebral near-infrared spectroscopy (NIRS) oximetry and implementation of an clinical treatment guideline based on intervention thresholds of cerebral regional tissue saturation rStO2. Methods/Design: SafeBoosC is a randomized, blinded, multinational, phase II clinical trial. The inclusion criteria are: neonates born more than 12 weeks preterm; decision to conduct full life support; parental informed consent; and possibility to place the cerebral NIRS oximeter within 3 hours after birth. The infants will be randomized into one of two groups. Both groups will have a cerebral oximeter monitoring device placed within three hours of birth. In the experimental group, the cerebral oxygenation reading will supplement the standard treatment using a predefined treatment guideline. In the control group, the cerebral oxygenation reading will not be visible and the infant will be treated according to the local standards. The primary outcome is the multiplication of the duration and magnitude of rStO2 values outside the target ranges of 55% to 85%, that is, the ‘burden of hypoxia and hyperoxia’ expressed in ‘%hours’. To detect a 50% difference between the experimental and control group in %hours, 166 infants in total must be randomized. Secondary outcomes are mortality at term date, cerebral ultrasound score, and interburst intervals on an amplitude-integrated electroencephalogram at 64 hours of life and explorative outcomes include neurodevelopmental outcome at 2 years corrected age, magnetic resonance imaging at term, blood biomarkers at 6 and 64 hours after birth, and adverse events. Discussion: Cerebral oximetry guided interventions have the potential to improve neurodevelopmental outcome in extremely preterm infants. It is a logical first step to test if it is possible to reduce the burden of hypoxia and hyperoxia. Trial registration: ClinicalTrial.gov, NCT0159031

A phase II randomized clinical trial on cerebral near-infrared spectroscopy plus a treatment guideline versus treatment as usual for extremely preterm infants during the first three days of life (SafeBoosC): study protocol for a randomized controlled trial.

BACKGROUND: Every year in Europe about 25,000 infants are born extremely preterm. These infants have a 20% mortality rate, and 25% of survivors have severe long-term cerebral impairment. Preventative measures are key to reduce mortality and morbidity in an extremely preterm population. The primary objective of the SafeBoosC phase II trial is to examine if it is possible to stabilize the cerebral oxygenation of extremely preterm infants during the first 72 hours of life through the application of cerebral near-infrared spectroscopy (NIRS) oximetry and implementation of an clinical treatment guideline based on intervention thresholds of cerebral regional tissue saturation rStO2. METHODS/DESIGN: SafeBoosC is a randomized, blinded, multinational, phase II clinical trial. The inclusion criteria are: neonates born more than 12 weeks preterm; decision to conduct full life support; parental informed consent; and possibility to place the cerebral NIRS oximeter within 3 hours after birth. The infants will be randomized into one of two groups. Both groups will have a cerebral oximeter monitoring device placed within three hours of birth. In the experimental group, the cerebral oxygenation reading will supplement the standard treatment using a predefined treatment guideline. In the control group, the cerebral oxygenation reading will not be visible and the infant will be treated according to the local standards. The primary outcome is the multiplication of the duration and magnitude of rStO2 values outside the target ranges of 55% to 85%, that is, the 'burden of hypoxia and hyperoxia' expressed in '%hours'. To detect a 50% difference between the experimental and control group in %hours, 166 infants in total must be randomized. Secondary outcomes are mortality at term date, cerebral ultrasound score, and interburst intervals on an amplitude-integrated electroencephalogram at 64 hours of life and explorative outcomes include neurodevelopmental outcome at 2 years corrected age, magnetic resonance imaging at term, blood biomarkers at 6 and 64 hours after birth, and adverse events. DISCUSSION: Cerebral oximetry guided interventions have the potential to improve neurodevelopmental outcome in extremely preterm infants. It is a logical first step to test if it is possible to reduce the burden of hypoxia and hyperoxia. TRIAL REGISTRATION: ClinicalTrial.gov, NCT01590316.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are