922 research outputs found
Ajatuksen ja toiminnan tiet : Matti Juntusen muistokirja
No full textMatti Juntunen (1943-1979) had many friends. He was known as a scientist and teacher especially at the universities of Jyvaskyla, Tampere and Turku. His friends and colleagues decided to dedicate this book to his memory. This book contains articles by Matti's teachers, colleagues and students. The first part of the book consists of articles by his teachers, the second part consists of "academic" articles by his colleagues and students and the third part contains articles of a more personal nature. There is not specific theme in this book. Instead, each writer deals with a subject of his own interest. The common aim of the writers has been a wish to honour the memory of Matti Juntunen.unknown accessibilityei tietoa saavutettavuudest
Poliisin yhteiskuntavastuu - pohdiskelua organisaatiotutkimuksen ja Matti Yrjänä Joensuun romaanien pohjalta
No full textThe article describes the societalresponsibility of the police administration fromtwo viewpoints: how it is present inadministrative science and administrativeculture of the police and what kind of picturecan be found in the Finnish detective novelswritten by Matti Yrjänä Joensuu. The focus ofthe article is to make administrative scientificand literal viewpoints to discuss with eachothers. The article is created by tworesearchers. Markku Temmes aims to useadministrative science which emphasizes therole of the police as a basic organisation inthe society and in the politico-administrativesystem. The second author of the articleVoitto Ruohonen has in this article and in hisdissertation tackled the societal picture of thenovels by Matti Yrjänä Joensuu from viewpointof literature and sociological research
Selluloosan nanokuituihin perustuvat materiaalit
No full textNanocelluloses are a novel class of materials, which have drawn significant interest due to their potential for high-performance sustainable materials. Cellulose nanofibrils (CNF) are an important subcategory of nanocelluloses, and this thesis explores possible routes for their processing in orderto achieve novel property combinations. Their morphology and surface properties as chemo-physical substrates are considered central for this purpose.
Several polysaccharides adsorb irreversibly on the CNF surface upon mixing in aqueous conditions. Exploiting this tendency, Publication 1 presents a facile strategy for enhancing the properties of CNF-based materials, namely the wet mechanical properties, by physical adsorption of a stimulus-responsive polysaccharide.
The CNF surface allows versatile covalent surface modifications. The introduction of surface charge enables CNF to complex with oppositely charged compounds. Publication 2 demonstrates the feasibilityof forming strong continuous CNF-based fibers by interfacial surface complexation with polyelectrolytes. This further enables facile fabrication of strictly compartmentalized bicomponent fibers, which can exhibit humidity-driven shape change.
CNF are an attractive material for high-performance fibers, but their uniaxial alignment by stretching results in embrittlement. Publication 3 explores the alignment of CNF by shear forces during extrusion. The use of long extrusion capillaries lead to alignment of the fibrils, and consequently stiff and strong fibers, but in contrast to the literature, without reducing extensibility. The explored processing route leads to CNF-based fibers of high toughness.
CNF have a very high persistence length and the fibrils readily bond to each other by hydrogen bonding. Therefore, CNF are well suited to fabricate porous materials, such as aerogels. Publication 4 demonstrates the feasibility of ambient drying of transparent CNF aerogel membranes and their use for fabricating transparent conductors by collecting a network of single-walled carbon nanotubes from a gas-phase synthesis process.
A CNF dispersion typically consists of fibrils with a distribution of diameters. Publication 5 demonstrates the tunability of the scattering properties of CNF-based materials by their porosity and constituent diameter distribution. Interestingly, light was shown to undergo superdiffusion in these strongly scattering materials.
This thesis gives insight on how the fundamental properties of CNF relate to the possible processing routes, and further to the feasibility of various property combinations, of CNF-based materials. The recognized processing routes offer direct possibilities from the industrial point of view, and the novel property combinations further extend the scope of potential applications of nanocelluloses.Selluloosan nanokuidut (SNK) ovat tärkeä nanoselluloosien kategoria ja ovat herättäneet kiinnostusta materiaalitieteissä, koska ne ovat lupaavia uusiutuvia raaka-aineita moniin sovelluksiin. Tässä työssä tutkitaan uusia valmistustapoja SNK:hin pohjautuville materiaaleille erilaisten ominaisuusyhdistelmien mahdollistamiseksi. Valmistustapojen kannalta SNK:jen keskeisinä piirteinä tunnistettiin niiden morfologia ja selluloosalle ominaiset kemiallis-fysikaaliset pintaominaisuudet.
Monet polysakkaridit sitoutuvat peruuttamattomasti SNK:jen pinnalle vesi-ympäristössä, mitä hyödyntäen Julkaisussa 1 esitetään yksinkertainen tapa muokata SNK:hin perustuvien materiaalien ominaisuuksia (tässä tapauksessa märkälujuutta) yhdistämällä SNK:t ärsykevasteisen polysakkaridin kanssa.
Selluloosan pintaa on mahdollista muokata myös kemiallisesti ja nanofibrillien pintavarausta lisättäessä ne voivat osallistua ioniseen kompleksointiin. Julkaisussa 2 esitetään tapa koostaa SNK:ista ja polyelektrolyyteistä pitkiä kuituja rajapintakompleksoinnilla vedessä. Esitetyllä valmistustavalla on helppoa valmistaa selkeästi osittuneita kaksikomponenttikuituja, jotka voivat muuttaa muotoaan vasteena ilmankosteuden muutoksiin.
SNK:t soveltuvat lujien ja jäykkien kuitujen koostamiseen, mutta niiden suuntautuneisuuden lisääminen venyttämällä johtaa kuitenkin tyypillisesti haurastumiseen. Julkaisussa 3 esitetään miten voi suunnata SNK:ja pursotusprosessin aiheuttamilla leikkausvoimilla ja saavuttaa paremmat mekaaniset ominaisuudetilman haurastumista. Näin aikaansaadaan ennennäkemättömän sitkeitä SNK-pohjaisia kuituja.
SNK:illa on korkea persistenssipituus ja taipumus sitoutua toisiinsa vetysidoksilla. Nämä ominaisuudet tekevät SNK:ista hyvin sopivia huokoisten materiaalien, kuten aerogeelien, valmistukseen. Julkaisussa 4 esitetään tapa valmistaa SNK:ista läpinäkyviä aerogeelimembraaneja huoneilman olosuhteissa. Nämä membraanit soveltuvat mm. kaasuvirtauksen suodatukseen ja läpinäkyvien ja taipuisien johtimien valmistamiseen.SNK:jen paksuusjakauma riippuu niiden valmistustavasta. Julkaisussa 5 esitetään miten SNK:ihin perustuvien materiaalien valonsirotustehokkuutta voidaan säätää huokoisuuden ja halkaisija-jakauman kautta. Valon eteneminen muuttuu superdiffusiiviseksi voimakkaimmin sirottavissa membraaneissa.
Tämä työ tarjoaa näkökulmia suhteeseen, joka vallitsee SNK:jen perusominaisuuksien, niiden käsittelytapojen ja ominaisuusyhdistelmien välillä. Työssä esitetyt käsittelytavat tarjoavat suoria kehityssuuntia kaupallisillekin toimijoille, sekä uudet saavutetut ominaisuuksien yhdistelmät laajentavat mahdollisten sovelluskohteiden kirjoa entisestään
Benchmarking and the bottom line
No full textMatti Siemiatycki presents the case for expanding and formalising performance benchmarking processes to address the persistent problems of escalating costs and missed deadlines in infrastructure and public works projects Copyright (c) 2009 The Author. Journal compilation (c) 2009 ippr.
Kummallinen yhdistelmä - Marskin ritari ja sosiologi
No full textMarskin ritari Paavo Koli : itseään käskenyt mies / Matti Parjanen. Tampere, 2009
A 24-hour dynamic population distribution dataset based on mobile phone data from Helsinki Metropolitan Area, Finland
No full textRelated article: Bergroth, C., Järv, O., Tenkanen, H., Manninen, M., Toivonen, T., 2022. A 24-hour population distribution dataset based on mobile phone data from Helsinki Metropolitan Area, Finland. Scientific Data 9, 39.
In this dataset:
We present temporally dynamic population distribution data from the Helsinki Metropolitan Area, Finland, at the level of 250 m by 250 m statistical grid cells. Three hourly population distribution datasets are provided for regular workdays (Mon – Thu), Saturdays and Sundays. The data are based on aggregated mobile phone data collected by the biggest mobile network operator in Finland. Mobile phone data are assigned to statistical grid cells using an advanced dasymetric interpolation method based on ancillary data about land cover, buildings and a time use survey. The data were validated by comparing population register data from Statistics Finland for night-time hours and a daytime workplace registry. The resulting 24-hour population data can be used to reveal the temporal dynamics of the city and examine population variations relevant to for instance spatial accessibility analyses, crisis management and planning.
Please cite this dataset as:
Bergroth, C., Järv, O., Tenkanen, H., Manninen, M., Toivonen, T., 2022. A 24-hour population distribution dataset based on mobile phone data from Helsinki Metropolitan Area, Finland. Scientific Data 9, 39. https://doi.org/10.1038/s41597-021-01113-4
Organization of data
The dataset is packaged into a single Zipfile Helsinki_dynpop_matrix.zip which contains following files:
HMA_Dynamic_population_24H_workdays.csv represents the dynamic population for average workday in the study area.
HMA_Dynamic_population_24H_sat.csv represents the dynamic population for average saturday in the study area.
HMA_Dynamic_population_24H_sun.csv represents the dynamic population for average sunday in the study area.
target_zones_grid250m_EPSG3067.geojson represents the statistical grid in ETRS89/ETRS-TM35FIN projection that can be used to visualize the data on a map using e.g. QGIS.
Column names
YKR_ID : a unique identifier for each statistical grid cell (n=13,231). The identifier is compatible with the statistical YKR grid cell data by Statistics Finland and Finnish Environment Institute.
H0, H1 ... H23 : Each field represents the proportional distribution of the total population in the study area between grid cells during a one-hour period. In total, 24 fields are formatted as “Hx”, where x stands for the hour of the day (values ranging from 0-23). For example, H0 stands for the first hour of the day: 00:00 - 00:59.
The sum of all cell values for each field equals to 100 (i.e. 100% of total population for each one-hour period)
In order to visualize the data on a map, the result tables can be joined with the target_zones_grid250m_EPSG3067.geojson data. The data can be joined by using the field YKR_ID as a common key between the datasets.
License
Creative Commons Attribution 4.0 International.
Related datasets
Järv, Olle; Tenkanen, Henrikki & Toivonen, Tuuli. (2017). Multi-temporal function-based dasymetric interpolation tool for mobile phone data. Zenodo. https://doi.org/10.5281/zenodo.252612
Tenkanen, Henrikki, & Toivonen, Tuuli. (2019). Helsinki Region Travel Time Matrix [Data set]. Zenodo. http://doi.org/10.5281/zenodo.324756
Sudden Death Associated with Incarcerated Small Bowel due to Mesodiverticular Band
No full textMeckel’s diverticulum is a congenital anomaly present in about 3% of the population and usually asymptomatic. Rarely, a mesodiverticular band extends from the tip of a Meckel’s diverticulum to the mesentery, thought to be due to lack of involution of the left vitelline artery. The presence of this band creates a closed loop through which loops of bowel can become entrapped. Rare case reports have described incarceration of bowel, and sudden death in children. We present such a case, and discuss this entity.Peer reviewe
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