Search

Tiivistelmä. Teknologia on olennainen osa nyky-yhteiskuntaa ja yhteiskunta kehittyy koko ajan yhä teknologisempaan suuntaan. Teknologian kehityksen takia tulevaisuudessa tullaan tarvitsemaan uusia innovaatioita, jotta voidaan säilyttää kestävä kehitys ja ratkaista kestävyysvaje. Tämän takia tulevaisuudessa tullaan tarvitsemaan enemmän teknologian, tekniikan, matemaattisten sekä luonnontieteellisten alojen osaajia. Teknologiakasvatus ja STEAM-toiminta pyrkivät vastaamaan tulevaisuuden osaajatarpeeseen innostamalla lapsia jo pienestä pitäen teknologian, tekniikan, matematiikan ja luonnontieteiden pariin. Teknologiakasvatuksella ja STEAM-toiminnalla oppilaille pyritään samalla opettamaan tulevaisuuden taitoja, kuten ongelmanratkaisun, luovan- ja kriittisen ajattelun, sekä ryhmätyöskentelytaitoja. Tutkielman tavoitteena on perehtyä teknologiakasvatukseen sekä STEAM-toimintaan ja tarkastella näiden kahden eroja ja yhtäläisyyksiä niiden määritelmien, tavoitteiden ja opetusmenetelmien kautta. Tutkimuksen teoreettinen viitekehys koostuu teknologiakasvatuksen, STEM:in ja STEAM:in määritelmistä sekä näiden yhtäläisyyksistä ja eroista määritelmien ja tavoitteiden tasolla. Tutkimuksessani pääpaino sijoittuu teknologiakasvatukseen ja STEAM:iin, mutta käsittelen myös STEM:iä sekä sen määritelmää, sillä se on olennainen osa STEAM:ia ja sen kehitystä. Olen toteuttanut tutkimukseni kirjallisuuskatsauksena ja tarkastelen aihettani aikaisempien tutkimusten perusteella. Teknologiakasvatus ja STEAM ovat ajankohtaisia aiheita, sillä teknologiakasvatus on ollut osa suomalaista perusopetusta jo useamman vuoden ajan, kun taas STEAM on suomalaisessa koulumaailmassa vielä suhteellisen tuore lähestymistapa opetukseen. Koska teknologiakasvatus on kentällä jo tuttu, olisi hyvä tarkastella ja tutkia STEAM:ia tarkemmin, jotta tietoisuutta ja ymmärrystä STEAM:ista saataisiin vietyä myös kentälle. Tutkimuksessa selviää, että teknologiakasvatuksella ja STEAM-toiminnalla on useita yhtymäkohtia keskenään. Molemmilla on myös yhteyksiä konstruktivistiseen oppimiskäsitykseen ja konstruktivistisiin opetusmenetelmiin.

Funding Information: The authors of PTB are grateful to Ingmar Müller who designed, set up and characterized the PQEDs calibrated by PTB and to Uwe Johannsen who set up and improved the cryogenic radiometer calibration facility of PTB. The research leading to these results has received funding from the European Community’s Seventh Framework Programme, ERA-NET Plus, under Grant Agreement No. 217257, from the European Metrology Research Programme (EMRP) Project SIB57 ‘New Primary Standards and Traceability for Radiometry’ and from the project 18SIB10 chipS.CALe (EMPIR). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union. The EMPIR programme is co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme. EI acknowledges the support by the Academy of Finland Flagship Programme, Photonics Research and Innovation (PREIN), decision number: 320167. Publisher Copyright: © 2022 BIPM & IOP Publishing Ltd. The stability of induced junction silicon photodiodes used to construct the predictable quantum efficient detector (PQED) has been studied over a time period of a decade by measurements of its spectral responsivity against absolute cryogenic radiometers (CR) in two independent laboratories at CMI and PTB. PQEDs operated at room temperature show a long-term temporal stability within 150 ppm over a broad spectral range during a 10-year period, well within the range of the claimed measurement uncertainty values of the CRs. This long term stability fulfills one of the fundamental requirements to establish a new primary standard for the measurement of power of optical radiation.

This paper develops an operation strategy for hybrid power production units (turbine integrated with energy storage) participating in the balancing of the power grid. The developed strategy targets the reduction of the mechanical stress of the hybrid’s turbine unit by utilizing the available storage capacity. The problem is addressed using the methods of operations research combined with the receding horizon control approach. The benefits of the operational strategy are demonstrated via numerical simulations.

This paper presents a robust soft sensor for estimating heat exchanger fouling in combustion–thermal power plant context. The approach is data–driven and focuses on identifying the effect of plant load changes to fouling estimation. Proposed method is applied to real process measurements and results are presented. The method consists of two blocks; a static energy balance calculation block for “traditional” fouling indicator calculation and a dynamic subspace identification block for finding sootblowing– and load level dynamics components of the static fouling indicator signal. Results from applying the proposed method to real plant data show that load level dynamics can be decoupled from static fouling estimate.

This paper presents the development and mathematical analysis of an open-channel flow model. A tanks-in-series model relying on systems engineering perspectives is constructed. Through a series of assumptions, the obtained nonlinear model is approximated by a linear dynamics, and its asymptotic modal behavior is analysed in infinite dimensions using rigorous mathematical machinery. The analysis exploits the repeating tridiagonal structure of the system matrix using Chebyshev polynomials and elaborates the dependence of the modal dynamics on the so-called flow coefficient, which accounts for the description of the flow of the model. The analysis presented in this paper reveals that using constant flow coefficient for flow description in cascade arrangement of liquid storages results in physically meaningless asymptotic modal behavior. The asymptotic modal behavior is well defined if the flow coefficient is an affine function or higher-order polynomial of the number of elements in the cascade structure.

Lataa OA-artikkeli, kun julkaistu. Light-emitting diodes (LEDs) have many applications in optical metrology. Depending on the measurement scheme, an LED might be driven, for example, using constant current, amplitude or pulsewidth modulated current, or current pulses. We present the design and characterization of a transconductance amplifier (TCA) optimized to drive LEDs in optical metrology applications. The device is capable of delivering peak and root mean square (rms) currents up to 10 and 1 A, respectively, and has a selectable transconductance ranging from 100 mu text{S} to 10 S. The typical cutoff frequency for the current output is around 10 MHz for various types of LEDs.

Foils made of different materials are often used as reflective insulators. Many manufacturers aim to accurately measure their optical properties to estimate and improve their performance. However, flat reflectance reference samples used in measurements do not correctly represent reflective insulators and cause discrepancies between different measurement techniques. The current work presents a method for modelling surface shape of appropriate reflectance reference samples that could be produced by additive manufacturing. The method is based on studying the reflection distribution of reflective insulators and is described with an example of aluminium foil. The method's performance is validated using Monte-Carlo simulations.

Cholesterol accumulation in late endosomes is a prevailing phenotype of Niemann-Pick type C1 (NPC1) mutant cells. Likewise, annexin A6 (AnxA6) overexpression induces a phenotype reminiscent of NPC1 mutant cells. Here, we demonstrate that this cellular cholesterol imbalance is due to AnxA6 promoting Rab7 inactivation via TBC1D15, a Rab7-GAP. In NPC1 mutant cells, AnxA6 depletion and eventual Rab7 activation was associated with peripheral distribution and increased mobility of late endosomes. This was accompanied by an enhanced lipid accumulation in lipid droplets in an acyl-CoA:cholesterol acyltransferase (ACAT)-dependent manner. Moreover, in AnxA6-deficient NPC1 mutant cells, Rab7-mediated rescue of late endosome-cholesterol export required the StAR-related lipid transfer domain-3 (StARD3) protein. Electron microscopy revealed a significant increase of membrane contact sites (MCS) between late endosomes and ER in NPC1 mutant cells lacking AnxA6, suggesting late endosome-cholesterol transfer to the ER via Rab7 and StARD3-dependent MCS formation. This study identifies AnxA6 as a novel gatekeeper that controls cellular distribution of late endosome-cholesterol via regulation of a Rab7-GAP and MCS formation. © 2019, The Author(s).

10 pags., 8 figs., 4 tabs. -- Open Access funded by Creative Commons Atribution Licence 3.0, In this paper, the fisheye camera method is validated for spatial non-uniformity corrections in luminous flux measurements with integrating spheres. The method was tested in eight integrating spheres with six LED lamps, and the determined angular intensity distributions and spatial non-uniformity correction factors were compared with the results of five goniophotometers. The average closeness score, describing the similarity between any two distributions, was 94.6 out of 100 for the distributions obtained using the fisheye camera method when compared with the goniophotometric results. The average closeness score for the five goniophotometers, when each goniophotometer was compared with the other four, was 96.6. On average, the relative deviation between the two methods was 0.05% when calculating the spatial corrections. The most significant sources of uncertainty for the fisheye camera method were large, view-obstructing sphere elements residing close to the camera port., The work leading to this study is partly funded by the European Metrology Programme for Innovation and Research (EMPIR) Project 15SIB07 PhotoLED ‘Future Photometry Based on Solid State Lighting Products’. The EMPIR initiative is cofunded by the European Union’s Horizon 2020 research and innovation programme and the EMPIR Participating States. Acknowledges the funded position of Aalto ELEC doctoral school and the support of the Tutkijat Maailmalle program.

Submitted document is an extended abstract.

CIE 2019, Washington DC, June 14 to 22, 2019. -- http://washington2019.cie.co.at, Angular intensity distributions of light sources are traditionally measured using goniophotometers. Usually, goniophotometers are expensive to obtain and resource intensive to operate, due to requirements of a dedicated laboratory and the time consuming nature of the measurements. In addition to other applications, such as lighting design, angular intensity distribution data are used for spatial corrections to increase accuracy of luminous flux measurements with integrating spheres. Because goniometric measurements are so laborious, many laboratories omit the spatial correction altogether, increasing their measurement uncertainty by up to a few percent, depending on the integrating sphere and the light source under test. Previously, the fisheye camera method was developed to enable faster and more cost-effective measurements of angular intensity distributions of light sources. Using the fisheye camera method, such angular distribution is obtained in a matter of seconds from a fisheye camera image captured through a port of an integrating sphere, while the sphere is illuminated by the lamp under test. The method was reported in CIE 2017 Midterm Meeting in Jeju, where doubts were presented about the wide applicability of the method and its comparability with traditional goniophotometers. In this study, the performance of the method is confirmed. The fisheye camera method is validated by measuring six LED lamps in eight integrating spheres of various configurations, and by comparing the obtained angular data with that measured using five goniophotometers of different types.