Search results for "AAL"

Acoustic wave tunneling across a vacuum gap between two piezoelectric crystals with arbitrary symmetry and orientation

2022

It is not widely appreciated that an acoustic wave can “jump” or “tunnel” across a vacuum gap between two piezoelectric solids, nor has the general case been formulated or studied in detail. Here, we remedy that situation, by presenting a general formalism and approach to study such an acoustic tunneling effect between two arbitrarily oriented anisotropic piezoelectric semi-infinite crystals. The approach allows one to solve for the reflection and transmission coefficients of all the partial-wave modes, and is amenable to practical numerical or even analytical implementation, as we demonstrate by a few chosen examples. The formalism can be used in the future for quantitative studies of the …

Digitaalisten kuvaväärennösten tunnistaminen JPEG-pakkausta hyödyntäen

2010

Digitaalisten valokuvien muokkaamisesta on tullut hyvin helppoa ja yleistä, mikä on nostanut esille huolen valokuvien uskottavuudesta. Ongelman ratkaisuksi on esitetty erilaisia tekniikoita, joilla valokuvien aitoutta voidaan arvioida. Tarkastelen tässä tutkielmassa niin sanottuja passiivisia tekniikoita, jotka eivät edellytä kuvasta minkäänlaista ennakkotietoa, kuten vesileimaa. Vertailen viittä tällaista tekniikkaa laatimani neljä kohtaa käsittävän kriteeristön pohjalta. Vertailtavia ominaisuuksia ovat tarkkuus, tunnistetut muokkaustyypit, rajoitukset sekä vakaus vastatoimia vastaan. Vertailu osoittaa, että eräs merkittävimmistä tekniikoiden ongelmista on niiden huono toleranssi kuvan häv…

Seeing red? Colour biases of foraging birds are context dependent.

2020

Funder: Suomen Kulttuurirahasto; doi: http://dx.doi.org/10.13039/501100003125

Multimodal Aposematic Signals and Their Emerging Role in Mate Attraction

2018

Chemically defended animals often display conspicuous color patterns that predators learn to associate with their unprofitability and subsequently avoid. Such animals (i.e., aposematic), deter predators by stimulating their visual and chemical sensory channels. Hence, aposematism is considered to be “multimodal.” The evolution of warning signals (and to a lesser degree their accompanying chemical defenses) is fundamentally linked to natural selection by predators. Lately, however, increasing evidence also points to a role of sexual selection shaping warning signal evolution. One of the species in which this has been shown is the wood tiger moth, Arctia plantaginis, which we here put forward…

From ‘no dogs here!’ to ‘beware of the dog!’ : restricting dog signs as a reflection of social norms

2019

Signs in public space reflect ‘normalcy’ in a community. The authors ask what restricting signs tell us about a society? In order to explore the system and variation in the ways dog signs manifest different norms and control, they compare two different data sets: dog signs in a Northern European town, Jyväskylä in Finland, and two Eastern European villages in Romania. They apply a qualitative methodology based on visual communication, geosemiotics and linguistic landscape studies. The focus of the article is on the resources of addressing and the visual semiotics of the image. The investigated communities seem to create a complementary distribution of what they regulate that is also displa…

Karoliinien soturiarvot : kunnian hallitsema maailmankuva Ruotsin valtakunnassa 1700-luvun alussa

2011

Effect of temperature on anaerobic treatment of black water in UASB-septic tank systems

2007

The effect of northern European seasonal temperature changes and low temperature on the performance of upflow anaerobic sludge blanket (UASB)-septic tanks treating black water was studied. Three UASB-septic tanks were monitored with different operational parameters and at different temperatures. The results indicated the feasibility of the UASB-septic tank for (pre)treatment of black water at low temperatures with respect to removal of suspended solids and dissolved organic material. Inoculum sludge had little effect on COD(ss) removal, though in the start-up phase some poorly adapted inoculum disintegrated and washed out, thus requiring consideration when designing the process. Removal of …

The sustainable lifestyle of Aalborg

2020

The strongest and most appealing image of Aalborg is its waterfront, facing the Limfjord that runs across Denmark, halfway between Kattegat and the North Sea. However, until a few decades ago, this water-“front” could have been described more likely as a sequence of “rears” of inaccessible, degraded and disused factories and abandoned port infrastructures. Fed by the strongest will power, the city council decided to adopt a new project in order to emerge from the economic crisis that, between the Seventies and Eighties, saw factories and industries shutting down one by one. The idea therefore was to reconvert the image of the city from an industrial and port center into a strategic, innovat…

Extended Families as Communities of Religious Experience in Late Seventeenth-Century Eastern Finland

2022

AbstractThis chapter offers an interpretation of extended families as communities of experience in a rural area close to the eastern border of the Swedish realm. Through a case study of lower court records, Kuha examines the social and religious life in a 17th-century farm culminating in the crisis of an extended family. The chapter explores how practices of lived religion shaped the relationship of the community and the individual, and how experiences were negotiated within families and local communities. The analysis highlights the importance of protecting the boundaries of the household as well as the meaning of religious practices in creating cohesion within the community.

Characterization of three-dimensional microstructure of composite materials by X-ray tomography

2016

Analysis methods for X-ray microtomographic images of short fibre composite materials were developed. The methods enable estimation of microstructural properties of the material, e.g., aspect ratio and orientation of fibres. Being based on X-ray microtomography and image analysis, the methods are nondestructive and do not require user intervention. In particular, a method for determination of the aspect ratio of fibres was first developed. The method contains an assumption about similarity of the shape of the fibres. The assumption was relaxed in an improved method that can estimate cross-sectional properties of fibres, too, e.g., cross-sectional area. Additionally, the effect of finite ima…