High-temperature surface superconductivity in topological flat-band systems

We show that the topologically protected flat band emerging on a surface of a nodal fermionic system promotes the surface superconductivity due to an infinitely large density of states associated with the flat band. The critical temperature depends linearly on the pairing interaction and can be thus considerably higher than the exponentially small bulk critical temperature. We discuss an example of surface superconductivity in multilayered graphene with rhombohedral stacking

Spin heat accumulation and its relaxation in spin valves

We study the concept of spin heat accumulation in excited spin valves, more precisely the effective electron temperature that may become spin dependent, both in linear response and far from equilibrium. A temperature or voltage gradient create non-equilibrium energy distributions of the two spin ensembles in the normal metal spacer, which approach Fermi-Dirac functions through energy relaxation mediated by electron-electron and electron-phonon coupling. Both mechanisms also exchange energy between the spin subsystems. This inter-spin energy exchange may strongly affect thermoelectric properties spin valves, leading, e.g., to violations of the Wiedemann-Franz law.Comment: 4 pages, 4 figures, close to published versio

Quantum transitions induced by the third cumulant of current fluctuations

We investigate the transitions induced by external current fluctuations on a small probe quantum system. The rates for the transitions between the energy states are calculated using the real-time Keldysh formalism for the density matrix evolution. We especially detail the effects of the third cumulant of current fluctuations inductively coupled to a quantum bit and propose a setup for detecting the frequency-dependent third cumulant through the transitions it induces.Comment: 4 pages, 3 figure

Giant current fluctuations in an overheated single electron transistor

Interplay of cotunneling and single-electron tunneling in a thermally isolated single-electron transistor (SET) leads to peculiar overheating effects. In particular, there is an interesting crossover interval where the competition between cotunneling and single-electron tunneling changes to the dominance of the latter. In this interval, the current exhibits anomalous sensitivity to the effective electron temperature of the transistor island and its fluctuations. We present a detailed study of the current and temperature fluctuations at this interesting point. The methods implemented allow for a complete characterization of the distribution of the fluctuating quantities, well beyond the Gaussian approximation. We reveal and explore the parameter range where, for sufficiently small transistor islands, the current fluctuations become gigantic. In this regime, the optimal value of the current, its expectation value, and its standard deviation differ from each other by parametrically large factors. This situation is unique for transport in nanostructures and for electron transport in general. The origin of this spectacular effect is the exponential sensitivity of the current to the fluctuating effective temperature.Comment: 10 pages, 11 figure

Visuaaliset menetelmät osallistavassa suunnittelussa

Tiivistelmä. Visuaalinen esittäminen ja performatiivisuus suunnittelukulttuurissa juontavat pitkältä historiasta ympäristön visualisoinnissa. Visualisoimalla tulevaisuuden tilallisia näkymiä voidaan parantaa merkittävästi osallistamista suunnittelussa. GIS (Geographic Information Systems) ovat tärkein kaupunkisuunnittelua tukeva teknologia. Visuaaliset metodit kuten 3D-visualisoinnit, havainnekuvat ja pehmoGIS (SoftGIS) ymmärretään potentiaalisina työkaluina osallistavissa suunnitteluprosesseissa, joissa halutaan parantaa kommunikaatiota suunnittelijan ja osallisten välillä. Tämä näkyy konkreettisesti kaupunkisuunnittelussa ja alueiden kehittämisessä Suomessa. Valmisteilla oleva maankäyttö- ja rakennuslaki tavoittelee laajaa digitalisaation hyödyntämistä maankäytön suunnittelussa. Sen tavoitteena on vahvistaa osallisuutta ja lisätä datan avoimempaa käyttöä rakentamisessa. Ympäristön havaitseminen visuaalisia työkaluja käyttämällä antaa katsojalle mahdollisuuden nähdä suunnittelun vaiheet konkreettisemmin ja liittämään siihen katsojan omiin lähtökohtiin pohjautuvaa kvalitatiivista dataa — kokemuksia, tarinallisuutta ja erilaisia merkityksiä katsojan tulkinnasta riippuen. Nähdään mahdollisena, että visuaaliset menetelmät ja työkalut suunnittelussa voisivat edistää osallistavan suunnittelun prosesseja, jotka toisinaan on nähty haastavina, joskin tarpeellisina. Osallistaminen kuuluu olennaisena osana demokraattiseen ja tasa-arvoiseen suunnitteluun, jossa tilan käyttäjillä on velvollisuus ja oikeus vaikuttaa. Osallistavia prosesseja vahvistamalla ja toteuttamalla ratkaisut ovat tehokkaampia ja noudattelevat yleistä hyötyä. Samoin vahva kansalaisosallistaminen avaa suunnittelijoille sokeita pisteitä ja edistää avointa suunnittelua. Ongelmallisena osallistamisessa nähdään eri sidosryhmien näennäinen valta vaikuttaa. Lisäksi sitä on kritisoitu vain osittaisesta osallistamisesta sellaisissa suunnittelun vaiheissa, jossa mielipiteet ovat vielä epärelevantteja tai mielipiteiden tueksi ei olla annettu riittävän paljon pohjustavaa tietoa. Toisaalta voidaan kyseenalaistaa, keillä henkilöillä ja sidosryhmillä on oikeus vaikuttaa kaupunkikuvaan ja alueiden suunnitteluun ja onko se ylipäänsä prosessin tulosta parantava keino. Suunnittelijan kyky fasilitoida osallistavia aktiviteetteja ja motivoida osallisia vaikuttamaan on haastava tehtävä mutta tavoitettavissa. Mikäli visualisointi on vakuuttavaa ja uskottavaa, sen on todettu parantavan sitoutumista ja motivaatiota vaikuttaa. Tutkielmani tarkastelee visualisointia osallistavan suunnittelun tukimenetelmänä ja pohtii sen potentiaalia ja mahdollisuuksia suunnittelussa. Kirjallisuus pohjautuu paljon visuaalisen suunnittelun ja osallistamisen keskeisiin piirteisiin ja olemukseen

Properties of local produced animal-fat based biodiesel and its blend with fossil fuel

In the near future, more emphasis must be put on reducing greenhouse gas (GHG) emissions in road transportation, house heating, agricultural activities, marine transport etc. This study concentrated on the use of alternative fuels in engine - driven applicat ions of non - road machineries and decentralized energy production . Today, the engines are mainly designed for crude oil derived fuels and liquid renewable fuels are blended with crude oil based fuels to fulfill the requirements of renewable energy usage. Du e to the environmental reasons on one hand and to the agricultural needs, on the other hand , different blends of bio - and fossil fuels are becoming more popular. In Europe, the maximum FAME content in diesel fuel is 7 vol% according to the EN 590:2013 but higher percentages are also available and targeted around the world. For example in the United States, the 20% blend fraction is becoming more common. For these reasons, B20 fuels were chosen to be investigated in this study. Special emphasis was put on im proving blending issues since fuel blending may cause some operating risks. The main aim was to research widely the properties of animal - fat based methyl ester (AFME) and B20 fuel blend produced from it. AFME is a waste based fuel and produced in Ostroboth nia region, Finland. The aim was to find out in which engine applications the fuels are feasible and investigate if the fuels fit in the quality of automotive fuel Standards. According to the results, AFME is a feasible option to increase self - sufficient e ne rgy production in Ostrobothnia.fi=vertaisarvioitu|en=peerReviewed

Exposure to electronic media was negatively associated with speech and language development at 18 and 24 months

Aim: This study evaluated early speech and language development at 18 and 24 months, and associated factors, based on parental reports. Method: We followed up the CHILD-SLEEP birth cohort of 1667 Finnish-speaking families, who were randomly recruited in 2011–2013 during routine visits to maternity clinics in the Pirkanmaa Hospital District of Finland. The women were approximately 32 weeks’ pregnant at enrolment. Parents reported the size of their child's expressive vocabulary, word combinations, intelligibility, finger-pointing and adherence to instructions. A subsample was studied using the Expressive Language subscale of the Bayley Scales of Infant and Toddler Development, Third Edition. Results: The children's vocabulary was smaller than previously reported. At 18 months of age, 68.8% of the 997 children had a vocabulary of 20 words or less and 35.7% used about five words at most. At 24 months, 32.4% of the 822 children had a vocabulary of 50 words or less and 18.4% used about 20 words at most. Longer child and parental exposure to electronic media was negatively associated with the size of the child's expressive vocabulary. Conclusion: Vocabulary size at 18 and 24 months was smaller than previously reported and negatively associated with exposure to electronic media.Aim This study evaluated early speech and language development at 18 and 24 months, and associated factors, based on parental reports. Method We followed up the CHILD-SLEEP birth cohort of 1667 Finnish-speaking families, who were randomly recruited in 2011-2013 during routine visits to maternity clinics in the Pirkanmaa Hospital District of Finland. The women were approximately 32 weeks' pregnant at enrolment. Parents reported the size of their child's expressive vocabulary, word combinations, intelligibility, finger-pointing and adherence to instructions. A subsample was studied using the Expressive Language subscale of the Bayley Scales of Infant and Toddler Development, Third Edition. Results The children's vocabulary was smaller than previously reported. At 18 months of age, 68.8% of the 997 children had a vocabulary of 20 words or less and 35.7% used about five words at most. At 24 months, 32.4% of the 822 children had a vocabulary of 50 words or less and 18.4% used about 20 words at most. Longer child and parental exposure to electronic media was negatively associated with the size of the child's expressive vocabulary. Conclusion Vocabulary size at 18 and 24 months was smaller than previously reported and negatively associated with exposure to electronic media.Peer reviewe

Observation of shot-noise-induced asymmetry in the Coulomb blockaded Josephson junction

We have investigated the influence of shot noise on the IV-curves of a single mesoscopic Josephson junction. We observe a linear enhancement of zero-bias conductance of the Josephson junction with increasing shot noise power. Moreover, the IV-curves become increasingly asymmetric. Our analysis on the asymmetry shows that the Coulomb blockade of Cooper pairs is strongly influenced by the non-Gaussian character of the shot noise.Comment: 4 pages, 5 figures, RevTE

Ins1 (Cre) knock-in mice for beta cell-specific gene recombination.

AIMS/HYPOTHESIS: Pancreatic beta cells play a central role in the control of glucose homeostasis by secreting insulin to stimulate glucose uptake by peripheral tissues. Understanding the molecular mechanisms that control beta cell function and plasticity has critical implications for the pathophysiology and therapy of major forms of diabetes. Selective gene inactivation in pancreatic beta cells, using the Cre-lox system, is a powerful approach to assess the role of particular genes in beta cells and their impact on whole body glucose homeostasis. Several Cre recombinase (Cre) deleter mice have been established to allow inactivation of genes in beta cells, but many show non-specific recombination in other cell types, often in the brain. METHODS: We describe the generation of Ins1 (Cre) and Ins1 (CreERT2) mice in which the Cre or Cre-oestrogen receptor fusion protein (CreERT2) recombinases have been introduced at the initiation codon of the Ins1 gene. RESULTS: We show that Ins1 (Cre) mice induce efficient and selective recombination of floxed genes in beta cells from the time of birth, with no recombination in the central nervous system. These mice have normal body weight and glucose homeostasis. Furthermore, we show that tamoxifen treatment of adult Ins1 (CreERT2) mice crossed with Rosa26-tdTomato mice induces efficient recombination in beta cells. CONCLUSIONS/INTERPRETATION: These two strains of deleter mice are useful new resources to investigate the molecular physiology of pancreatic beta cells

The connection between migration and regional structure in Finland around 1990 - a GIS viewpoint

The connection between migration and regional structure in Finland in the early 19905 is discussed on the basis of Geographic Irformation Systems (GIS) data from Statistics Finland, compiled for map coordinate grid cells of 1 x 1 km. The results indicate that data of this kind enable a more detailed typology to be drawn up for migration. At the regional level, this allows the defining of places of "passing through '' which gain population from other local government districts but lose population through migration within their own district. The connection between migration and regional structure is manifested in the fact that flows both between and within local government districts mainly involve the more urbanised population centres and areas with: high levels of unemployment