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Institution

Helsinki University of Technology

About: Helsinki University of Technology is a based out in . It is known for research contribution in the topics: Thin film & Vortex. The organization has 8962 authors who have published 20136 publications receiving 723787 citations. The organization is also known as: TKK & Teknillinen korkeakoulu.


Papers
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Proceedings ArticleDOI
12 Apr 2007
TL;DR: In this paper, a generalized formulation for determining the optimal operating strategy and cost optimization scheme as well as reducing the emissions of a microgrid (MG) is presented. And the optimization is aimed at minimizing the cost function of the system while constraining it to meet the costumer demand and safety.
Abstract: This paper presents a generalized formulation for determining the optimal operating strategy and cost optimization scheme as well as reducing the emissions of a MicroGrid (MG). Multiobjective (MO) optimization is applied to the environmental economic problem of the MG. The proposed problem is formulated as a nonlinear constrained MO optimization problem Prior to the optimization, system model components taken from real manufactural data are constructed. The model takes into consideration the operation and maintenance costs as well as the reduction in emissions of NOx, SO 2 , and CO 2 . The MG considered in this paper consists of a wind turbine, a micro turbine, a diesel generator, a photovoltaic array, a fuel cell, and a battery storage. The optimization is aimed at minimizing the cost function of the system while constraining it to meet the costumer demand and safety of the system. The results demonstrate the efficiency of the proposed approach to satisfy the load and to reduce the cost and the emissions in one single run.

144 citations

Journal ArticleDOI
TL;DR: In this article, the size of bubbles in flotation cells was measured using the UCT bubble size meter and the HUT bubble size analyser, and the results revealed important differences.

144 citations

Journal ArticleDOI
A. A. Abdo1, A. A. Abdo2, A. A. Abdo3, Markus Ackermann4  +262 moreInstitutions (55)
TL;DR: In this article, the authors report on the multi-wavelength observations of PKS 1510-089 (a flat spectrum radio quasar) at z = 0.361 during its high activity period between 2008 September and 2009 June.
Abstract: We report on the multi-wavelength observations of PKS 1510-089 (a flat spectrum radio quasar (FSRQ) at z = 0.361) during its high activity period between 2008 September and 2009 June. During this 11 month period, the source was characterized by a complex variability at optical, UV, and gamma-ray bands, on timescales down to 6-12 hr. The brightest gamma-ray isotropic luminosity, recorded on 2009 March 26, was similar or equal to 2 x 1048 erg s-1. The spectrum in the Fermi Large Area Telescope energy range shows a mild curvature described well by a log-parabolic law, and can be understood as due to the Klein-Nishina effect. The. -ray flux has a complex correlation with the other wavelengths. There is no correlation at all with the X-ray band, a weak correlation with the UV, and a significant correlation with the optical flux. The. -ray flux seems to lead the optical one by about 13 days. From the UV photometry, we estimated a black hole mass of similar or equal to 5.4 x 10(8)M(circle dot) and an accretion rate of similar or equal to 0.5M(circle dot) yr(-1). Although the power in the thermal and non-thermal outputs is smaller compared to the very luminous and distant FSRQs, PKS 1510-089 exhibits a quite large Compton dominance and a prominent big blue bump (BBB) as observed in the most powerful gamma-ray quasars. The BBB was still prominent during the historical maximum optical state in 2009 May, but the optical/ UV spectral index was softer than in the quiescent state. This seems to indicate that the BBB was not completely dominated by the synchrotron emission during the highest optical state. We model the broadband spectrum assuming a leptonic scenario in which the inverse Compton emission is dominated by the scattering of soft photons produced externally to the jet. The resulting model-dependent jet energetic content is compatible with a scenario in which the jet is powered by the accretion disk, with a total efficiency within the Kerr black hole limit.

143 citations

Journal ArticleDOI
TL;DR: The first DTI and tractography results of human distal peripheral nerves are presented, showing that DTI is a quantitative method that could provide useful information for the diagnosis and follow-up of nerve lesions, entrapments, and regeneration.

143 citations

Journal ArticleDOI
TL;DR: In this article, a series of temperature-responsive polystyrene-block-poly(N-isopropylacrylamide)-blockpolystyrene triblock copolymers were synthesized using reversible addition−fragmentation chain transfer (RAFT) polymerization.
Abstract: This work describes the synthesis of temperature-responsive polystyrene-block-poly(N-isopropylacrylamide)-block-polystyrene triblock copolymers, i.e., PS-b-PNIPAM-b-PS, their self-assembly and phase behavior in bulk, and demonstration of aqueous thermoresponsive membranes. A series of PS-b-PNIPAM-b-PS triblock copolymers were synthesized using reversible addition−fragmentation chain transfer (RAFT) polymerization. The hydrophobic PS end blocks were selected to form the minority component, whereas the temperature-responsive PNIPAM midblock accounted for the majority component. The self-assembly and phase behavior in bulk of PS-b-PNIPAM-b-PS as well as selected blends with low molecular weight PNIPAM homopolymers were studied using transmission electron microscopy (TEM). Classical lamellar, cylindrical, spherical, and bicontinuous double gyroid morphologies were observed in the dried state. In aqueous solutions, the glassy PS domains act as physical cross-links, and hydrogels were therefore formed. The bulk...

143 citations


Authors

Showing all 8962 results

NameH-indexPapersCitations
Ashok Kumar1515654164086
Hannu Kurki-Suonio13843399607
Nicolas Gisin12582764298
Anne Lähteenmäki11648581977
Riitta Hari11149143873
Andreas Richter11076948262
Mika Sillanpää96101944260
Markku Leskelä9487636881
Ullrich Scherf9273536972
Mikko Ritala9158429934
Axel H. E. Müller8956430283
Karl Henrik Johansson88108933751
T. Poutanen8612033158
Elina Lindfors8642023846
Günter Breithardt8555433165
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
2021154
2020153
2019155
201851
201714
201630