Browsing by Subject "measurement"

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  • Westman, Carl Johan; Starr, Michael; Laine, Jukka (Suomen metsätieteellinen seura, 1985)
  • Rufelt, Henry; Wiese, Björn (Suomen metsätieteellinen seura, 1981)
  • Calderón, Silvia M.; Tonttila, Juha; Buchholz, Angela; Joutsensaari, Jorma; Komppula, Mika; Leskinen, Ari; Hao, Liqing; Moisseev, Dmitri; Pullinen, Iida; Tiitta, Petri; Xu, Jian; Virtanen, Annele; Kokkola, Harri; Romakkaniemi, Sami (Copernicus Publ., 2022)
    Atmospheric chemistry and physics
    We carried out a closure study of aerosol-cloud interactions during stratocumulus formation using a large eddy simulation model UCLALES-SALSA and observations from the 2020 cloud sampling campaign at the Puijo SMEAR IV station in Kuopio, Finland. The unique observational setup combining in situ and cloud remote sensing measurements allowed a closer look into the aerosol size-composition dependence of droplet activation and droplet growth in turbulent boundary layer driven by surface forcing and radiative cooling. UCLALES-SALSA uses spectral bin microphysics for aerosols and hydrometeors and incorporates a full description of their interactions into the turbulent-convective radiation-dynamical model of stratocumulus. Based on our results, the model successfully described the probability distribution of updraft velocities and consequently the size dependency of aerosol activation into cloud droplets, and further recreated the size distributions for both interstitial aerosol and cloud droplets. This is the first time such a detailed closure is achieved not only accounting for activation of cloud droplets in different updrafts, but also accounting for processes evaporating droplets and drizzle production through coagulation-coalescence. We studied two cases of cloud formation, one diurnal (24 September 2020) and one nocturnal (31 October 2020), with high and low aerosol loadings, respectively. Aerosol number concentrations differ more than 1 order of magnitude between cases and therefore, lead to cloud droplet number concentration (CDNC) values which range from less than 100cm-3 up to 1000cm-3. Different aerosol loadings affected supersaturation at the cloud base, and thus the size of aerosol particles activating to cloud droplets. Due to higher CDNC, the mean size of cloud droplets in the diurnal-high aerosol case was lower. Thus, droplet evaporation in downdrafts affected more the observed CDNC at Puijo altitude compared to the low aerosol case. In addition, in the low aerosol case, the presence of large aerosol particles in the accumulation mode played a significant role in the droplet spectrum evolution as it promoted the drizzle formation through collision and coalescence processes. Also, during the event, the formation of ice particles was observed due to subzero temperature at the cloud top. Although the modeled number concentration of ice hydrometeors was too low to be directly measured, the retrieval of hydrometeor sedimentation velocities with cloud radar allowed us to assess the realism of modeled ice particles. The studied cases are presented in detail and can be further used by the cloud modellers to test and validate their models in a well-characterized modelling setup. We also provide recommendations on how increasing amount of information on aerosol properties could improve the understanding of processes affecting cloud droplet number and liquid water content in stratiform clouds.
  • Hari, Pertti; Kanninen, Markku; Kellomäki, Seppo; Luukkanen, Olavi; Pelkonen, Paavo; Salminen, Raimo; Smolander, Heikki (Suomen metsätieteellinen seura, 1979)
  • Kunnari, Anton; Sundvall, Jukka R. I.; Laakasuo, Michael (2020)
    The process dissociation procedure (PDP) for moral cognition was created to separately measure two dispositions of moral judgment based on the dual-process theory of moral reasoning: deontological and utilitarian inclinations. In this paper we raise some concerns from a psychometrics perspective regarding the structure, reliability, and validity of the moral PDP as a measure of individual differences. Using two simulation studies as well as a real sample of N = 1,010, we investigate the psychometric properties of the moral PDP. We present novel evidence showing that (1) some correlations between PDP parameters are mathematical artifacts, and as such cannot be taken as evidence in support of a theory, (2) there are severe response inconsistencies within dilemma batteries, and (3) reliability estimates for these scores seem to be far below the accepted standards. We discuss some potential theoretical and content-related reasons for these statistical issues and their implications. We conclude that in their current form, PDP measures of utilitarian and deontological tendencies are sub-optimal for assessing individual differences.
  • Berg, Annukka; Antikainen, Riina; Hartikainen, Ernesto; Kauppi, Sari; Kautto, Petrus; Lazarevic, David; Piesik, Sandra; Saikku, Laura (Finnish Environment Institute, 2018)
    Reports of the Finnish Environment Institute 26/2018
    As a new paradigm for economic development, the circular economy has significant environmental, economic and social benefits at the global scale. The circular economy concept highlights the notion of replacing the ‘end-of-life’ in current production and consumption practices by reducing, reusing, and recycling products and materials in production, distribution and consumption processes. Promoting circularity aims to accomplish sustainable development, and the circular economy has links to many of the 17 Sustainable Development Goals (SDGs) approved by the United Nations in 2015. This report is a background contribution asked by the Independent group of scientists writing the Global Sustainable Development Report (GSDR) 2019. The GSDR 2019 is the first in a series of comprehensive, in-depth Reports that will be produced every four years to inform the High-level Political Forum on Sustainable Development convened under the auspices of the General Assembly. Thus, this background report seeks to provide a condensed package on the circular economy; the concept, its history, potentials, business opportunities, management and measurement. Some of the key messages entail that moving towards a circular economy presents vast opportunities for businesses of various kind, and that increasing the material circularity of economy can also be a way to alleviate poverty. Yet, the systemic and disruptive changes required for a circular economy transition will not take place without significant changes to existing regulatory structures.
  • Sulkunen, Pekka (2017)
  • Luo, Fuhe (Suomen metsätieteellinen seura, 1983)
  • Saarilahti, Martti (Suomen metsätieteellinen seura, 1988)
  • Kaipio, Johanna; Karisalmi, N.; Hiekkanen, K.; Stenhammar, H.; Lahdenne, P. (IOS PRESS, 2019)
    Studies in Health Technology and Informatics
    Patient experience (PX) is an important evaluation criterion for quality in healthcare. Compared to patient satisfaction, however less research has focused on the development of instruments to measure experiences of patients and their families. In the article, we describe the process of developing a PX questionnaire for the parents of pediatric patients in the context of children's hospital and illustrate the questionnaire items for measuring PX. The phases of the development process included retrospective interviews, description of the themes influencing PX and the metrics for measuring PX, as well as iterative development of three versions of questionnaires including data gathering and factor analysis. The final versions of the surveys suggested for implementation at the hospitals include eight PX statements for the outpatient clinic and five statements for the ward. Compared to satisfaction surveys, the developed surveys emphasize the aspects of parent's attitude towards the illness, support for families, and daily arrangements with a child patient. © 2019 American Psychological Association Inc. All rights reserved.
  • Harni, Sami D.; Saarikoski, Sanna; Kuula, Joel; Helin, Aku; Aurela, Minna; Niemi, Jarkko V.; Kousa, Anu; Rönkkö, Topi; Timonen, Hilkka (Pergamon., 2023)
    Atmospheric environment
    Particle size distribution is a major factor in the health and climate effects of ambient aerosols, and it shows a large variation depending on the prevailing atmospheric emission sources. In this work, the particle number size distributions of ambient air were investigated at a suburban detached housing area in northern Helsinki, Finland, during a half-year period from winter to summer of 2020. The measurements were conducted with a scanning mobility particle sizer (SMPS) with a particle size range of 16–698 nm (mobility diameter), and the events with a dominant particle source were identified systematically from the data based on the time of the day and different particle physical and chemical properties. During the measurement period, four different types of events with a dominant contribution from either wood-burning (WB), traffic (TRA), secondary biogenic (BIO), or long-range transported (LRT) aerosol were observed. The particle size was the largest for the LRT events followed by BIO, WB, and TRA events with the geometric mean diameters of 72, 62, 57, and 41 nm, respectively. BIO and LRT produced the largest particle mode sizes followed by WB, and TRA with the modes of 69, 69, 46, and 25 nm, respectively. Each event type had also a noticeably different shape of the average number size distribution (NSD). In addition to the evaluation of NSDs representing different particle sources, also the effects of COVID-19 lockdown on specific aerosol properties were studied as during the measurement period the COVID-19 restrictions took place greatly reducing the traffic volumes in the Helsinki area in the spring of 2020. These restrictions had a significant contribution to reducing the concentrations of NOx and black carbon originating from fossil fuel combustion concentration, but insignificant effects on other studied variables such as number concentration and size distribution or particle mass concentrations (PM1, PM2.5, or PM10).
  • Bettencourt da Silva, Ricardo J.N; Saame, Jaan; Anes, Bárbara; Heering, Agnes; Leito, Ivo; Näykki, Teemu; Stoica, Daniela; Deleebeeck, Lisa; Bastkowski, Frank; Snedden, Alan; Camões, M. Filomena (Elsevier, 2021)
    Analytica Chimica Acta 1182 (2021), 338923
    The use of the unified pH concept, pHabsH2O, applicable to aqueous and non-aqueous solutions, which allows interpreting and comparison of the acidity of different types of solutions, requires reliable and objective determination. The pHabsH2O can be determined by a single differential potentiometry measurement referenced to an aqueous reference buffer or by a ladder of differential potentiometric measurements that allows minimisation of inconsistencies of various determinations. This work describes and assesses bottom-up evaluations of the uncertainty of these measurements, where uncertainty components are combined by the Monte Carlo Method (MCM) or Taylor Series Approximation (TSM). The MCM allows a detailed simulation of the measurements, including an iterative process involving in minimising ladder deviations. On the other hand, the TSM requires the approximate determination of minimisation uncertainty. The uncertainty evaluation was successfully applied to measuring aqueous buffers with pH of 2.00, 4.00, 7.00, and 10.00, with a standard uncertainty of 0.01. The reference and estimated values from both approaches are metrologically compatible for a 95% confidence level even when a negligible contribution of liquid junction potential uncertainty is assumed. The MCM estimated pH values with an expanded uncertainty, for the 95% confidence level, between 0.26 and 0.51, depending on the pH value and ladder inconsistencies. The minimisation uncertainty is negligible or responsible for up to 87% of the measurement uncertainty. The TSM quantified measurement uncertainties on average only 0.05 units larger than the MCM estimated ones. Additional experimental tests should be performed to test these uncertainty models for analysis performed in other laboratories and on non-aqueous solutions.
  • Korhonen, Keijo (Helsingin yliopisto, 2022)
    The variational quantum eigensolver (VQE) is one of the most promising proposals for a hybrid quantum-classical algorithm made to take advantage of near-term quantum computers. With the VQE it is possible to find ground state properties of various of molecules, a task which many classical algorithms have been developed for, but either become too inaccurate or too resource-intensive especially for so called strongly correlated problems. The advantage of the VQE comes in the ability of a quantum computer to represent a complex system with fewer so-called qubits than a classical computer would with bits, thus making the simulation of large molecules possible. One of the major bottlenecks for the VQE to become viable for simulating large molecules however, is the scaling of the number of measurements necessary to estimate expectation values of operators. Numerous solutions have been proposed including the use of adaptive informationally complete positive operator-valued measures (IC-POVMs) by García-Pérez et al. (2021). Adaptive IC-POVMs have shown to improve the precision of estimations of expectation values on quantum computers with better scaling in the number of measurements compared to existing methods. The use of these adaptive IC-POVMs in a VQE allows for more precise energy estimations and additional expectation value estimations of separate operators without any further overhead on the quantum computer. We show that this approach improves upon existing measurement schemes and adds a layer of flexibility, as IC-POVMs represent a form of generalized measurements. In addition to a naive implementation of using IC-POVMs as part of the energy estimations in the VQE, we propose techniques to reduce the number of measurements by adapting the number of measurements necessary for a given energy estimation or through the estimation of the operator variance for a Hamiltonian. We present results for simulations using the former technique, showing that we are able to reduce the number of measurements while retaining the improvement in the measurement precision obtained from IC-POVMs.
  • Tiitta, Petri; Leskinen, Ari; Kaikkonen, Ville A.; Molkoselkä, Eero O.; Mäkynen, Anssi J.; Joutsensaari, Jorma; Calderon, Silvia; Romakkaniemi, Sami; Komppula, Mika (Copernicus publications, 2022)
    Atmospehric measurement techniques
    Upon a new measurement technique, it is possible to sharpen the determination of microphysical properties of cloud droplets using high resolving power imaging. The shape, size, and position of each particle inside a welldefined, three-dimensional sample volume can be measured with holographic methods without assumptions of particle properties. In situ cloud measurements were carried out at the Puijo station in Kuopio, Finland, focusing on intercomparisons between cloud droplet analyzers over 2 months in September–November 2020. The novel holographic imaging instrument (ICEMET) was adapted to measure microphysical properties of liquid clouds, and these values were compared with parallel measurements of a cloud droplet spectrometer (FM-120) and particle measurements using a twininlet system. When the intercomparison was carried out during isoaxial sampling, our results showed good agreement in terms of variability between the instruments, with the averaged ratios between ICEMET and FM-120 being 0.6 ± 0.2, 1.0 ± 0.5, and 1.2 ± 0.2 for the total number concentration (Nd) of droplets, liquid water content (LWC), and median volume diameter (MVD), respectively. This agreement during isoaxial sampling was also confirmed by mutual correlation and Pearson correlation coefficients. The ICEMETobserved LWC was more reliable than FM-120 (without a swivel-head mount), which was verified by comparing the estimated LWC to measured values, whereas the twin-inlet DMPS system and FM-120 observations of Nd showed good agreement both in variability and amplitude. Field data revealed that ICEMET can detect small cloud droplets down to5 µm via geometric magnification.
  • Alasaarela, Juha (Helsingin yliopisto, 2019)
    Ruukkusalaattien tuotanto on kasvanut Suomessa jo vuosikymmeniä. Kasvihuoneet mahdollistavat tuoreiden lehtivihannesten kasvatuksen ympärivuotisesti, mutta pimeä vuodenaika tai valonsaannin heikentyminen yhdessä korkean nitraattilannoituksen kanssa aiheuttavat nitraatin kertymistä salaattiin. Nitraatti ei itsessään ole kovin myrkyllistä ihmiselle, mutta sen aineenvaihduntatuotteet elimistössä voivat olla haitallisia. Siksi ravinnon nitraattipitoisuuksia rajoitetaan EU asetuksella ja kasvisten nitraattipitoisuuksia valvoo Ruokavirasto. Tutkimuksen tavoitteena oli selvittää jääsalaatin (Lactuca sativa L.) nitraattipitoisuuteen vaikuttavia tekijöitä yksityisellä kasvihuonepuutarhalla, ja ehdottaa helposti sovellettavia keinoja nitraattipitoisuuden alentamiseksi. Tutkimuksessa mitattiin vuorokaudenajan, iän ja olosuhteiden vaikutusta jääsalaatin nitraattipitoisuuteen. Mittaukset tehtiin eri kellonaikoina korjatuilta salaateilta, neljän, viiden ja kuuden viikon ikäisiltä salaateilta, sekä viikoittaisilla seurantamittauksilla kolmen kuukauden ajan syksyllä 2017. Salaattien nitraattipitoisuus määriteltiin pikamittausmenetelmällä. Kasveille tulevaa PAR-valoa ja kiertoliuoksen nitraattityppipitoisuutta mitattiin jatkuvatoimisella mittalaitteella. Lisäksi kasvihuoneen automaattisesta ohjausjärjestelmästä saatiin tietoa muista kasvuolosuhteista. Sadonkorjuun kellonaika ei vaikuttanut jääsalaatin nitraattipitoisuuteen. Ikä vaikutti neljän ja viiden viikon ikäisten salaattien nitraattipitoisuuteen, mutta paremmissa valo-olosuhteissa iän vaikutus heikkeni kuuden viikon ikäisillä salaateilla. Nitraattityppilannoituksella ei ollut suoraa vaikutusta salaatin nitraattipitoisuuteen, mutta enemmän valoa saaneissa salaateissa oli vähemmän nitraattia. Kasvuston tasolta tehdystä jatkuvatoimisesta valon mittauksesta on hyötyä salaatin nitraattipitoisuuden hallinnassa. Riski nitraatin enimmäispitoisuusrajan ylitykseen on suuri syyskuussa luonnonvalon määrän vähentyessä. Tekovalojen käytön lisäämisellä voidaan alentaa salaatin nitraattipitoisuutta.
  • Smolander, Heikki (Suomen metsätieteellinen seura, 1984)
    Measurements were made of temporal and spatial microvariations in irradiance in a small part of the canopy of a 20-yr-old Scots pine stand. Linear integration of the variations gave biased estimates; second order Taylor series approximations were satisfactory only for a low curvature response; two-point distribution approximations were applicable to high and low curvature response but presupposed that the mean and variance were known. It is suggested that a light measuring method in which first power (mean) and second power (variance) of irradiance are integrated resolves these problems; the method takes into account the geometry of the shoot and can also be used in transpiration studies.
  • ten Brink, H.M.; Hitzenberger, R.; Virkkula, A. (Pergamon., 2022)
    Atmospheric environment
    Air pollution by diesel traffic became a concern in the UK in the 1950s. Exposure levels were assessed via probing the light absorption of filter samples, which was translated to a mass concentration of “diesel smoke” (DS), based on the results of a measurements in the exhaust of a test diesel engine. We convert these DS values to concentrations of Elemental Carbon (EC), the current proxy for diesel exhaust. In a recent study in the literature and an earlier own investigation a high similarity (R2 = 0.97) was found of the light absorption by aerosol collected in parallel on glass and quartz fibre filters and probed by smoke-stain reflectometers similar to those used historically. For samples on quartz fibre filters the relation between light absorption and EC was taken from recent studies. The shape of the absorption/EC curve is highly similar to the absorption/DS curve, with an equivalency factor of 1.6 ± 20% between DS and EC concentration (expressed according to the EUSAAR2-TOT method). Converted EC concentrations for workday average 24-hr and morning rush hour samples were around 75 and 150 μg m− 3 at the kerbside of the busy London A1 ring-road in 1960. In 1961–1962 the average weekday daytime EC concentration at a traffic island in inner city Fleet Street was 200–250 μg m− 3. Only 45 m into a sidestreet the concentration was an order of magnitude less. At the end of the 1990-ies EC concentrations at the nearby Marylebone Road were around 9 μg m− 3, dropping to 3 μg m− 3 in recent years. In addition, we found the correct factor to convert light absorption to EC mass concentration of samples obtained in the FH62 beta gauge monitors used in Germany in compliance measurements for the national “soot law” preceeding the EU PM10 regulation of 1997.
  • Kuusipalo, Jussi (Suomen metsätieteellinen seura, 1985)