Tallinn University of Technology

About: Tallinn University of Technology is a education organization based out in Tallinn, Estonia. It is known for research contribution in the topics: European union & Oil shale. The organization has 3688 authors who have published 10313 publications receiving 145058 citations. The organization is also known as: Tallinn Technical University & Tallinna Tehnikaülikool.

National Varieties of Public–Private Partnerships (PPPs): A Comparative Analysis of PPP-Supporting Units in 19 European Countries

Abstract: Most countries that have adopted the public–private partnership (PPP) model as a means of implementing infrastructure projects have launched dedicated supporting units to guide policy development and stimulate project implementation. This paper draws on the theoretical notion of PPP-enabling fields to carry out a comparative analysis of the roles and functions of PPP-supporting units across 19 European countries with varying PPP experiences. We distinguish four categories of national support of PPPs, from skeptical systems of zero support to full-fledged PPP systems. Furthermore, we take initial steps to analyze the possible link between national differences in institutionalized PPP support and the amount of implemented PPP projects. Finally, pathways for further research on PPP-supporting units are discussed.

Catalytic ozonation of m-dinitrobenzene

Abstract: The efficiency of catalytic ozonation with homogeneous (containing dissolved ions of Fe2+, Mn2+, Cu2+, Ni2+, Co2+, V5+, Cr3+, Mo6+) and heterogeneous (MnO2, Ni2O3, Fe2O3, CuO, Al2O3, CoO, V2O5, Cr2O3, MoO3, TiO2) catalysts and non-accompanied ozonation was compared for degradation of m-dinitrobenzene (m-DNB). Several transition metals in homogeneous and heterogeneous form improved significantly the ozone performance for degradation of m-DNB. This improvement was found to be due to supplementary formation of reactive species (hydroxyl radicals) and better ozone utilization. The effects observed were found to be strongly dependent on the treatment conditions.

Test Configurations for Diagnosing Faulty Links in NoC Switches

Abstract: The paper proposes a new concept of diagnosing faulty links in network-on-a-chip (NoC) designs. The method is based on functional fault models and it implements packet address driven test configurations. As previous works have shown, such configurations can be applied for achieving near-100 per cent structural fault coverage for the network switches. The main novel contribution of this paper is to extend the use of test configurations for diagnosis purposes and to propose a method for locating faults in the NoC interconnection infrastructure. Additionally, a new concept of functional switch faults, called link faults, is introduced. The approach is well scalable (complexity is square root of the number of switches) and it is capable of unambiguously pinpointing the faulty links inside the switching network.

The electrical and optical properties of kesterites

Abstract: Kesterite Cu2ZnSn(SxSe1-x)4 (CZTSSe) semiconductor materials have been extensively studied over the past decade, however despite significant efforts, the open circuit voltage remains below 60% of the theoretical maximum. Understanding the optical and electrical properties is critical to explaining and solving the voltage deficit. This review aims to summarize the present knowledge of optical and electrical properties of kesterites and specifically focuses on experimental data of intrinsic defects, charge carrier density and transport, and minority carrier lifetime and related rate-limiting recombination mechanisms. It concludes with suggestions for further investigation of the electrical and optical properties of kesterite materials.

Surface wave effects on water temperature in the Baltic Sea: simulations with the coupled NEMO-WAM model

Abstract: Coupled circulation (NEMO) and wave model (WAM) system was used to study the effects of surface ocean waves on water temperature distribution and heat exchange at regional scale (the Baltic Sea). Four scenarios—including Stokes-Coriolis force, sea-state dependent energy flux (additional turbulent kinetic energy due to breaking waves), sea-state dependent momentum flux and the combination these forcings—were simulated to test the impact of different terms on simulated temperature distribution. The scenario simulations were compared to a control simulation, which included a constant wave-breaking coefficient, but otherwise was without any wave effects. The results indicate a pronounced effect of waves on surface temperature, on the distribution of vertical temperature and on upwelling’s. Overall, when all three wave effects were accounted for, did the estimates of temperature improve compared to control simulation. During the summer, the wave-induced water temperature changes were up to 1 °C. In northern parts of the Baltic Sea, a warming of the surface layer occurs in the wave included simulations in summer months. This in turn reduces the cold bias between simulated and measured data, e.g. the control simulation was too cold compared to measurements. The warming is related to sea-state dependent energy flux. This implies that a spatio-temporally varying wave-breaking coefficient is necessary, because it depends on actual sea state. Wave-induced cooling is mostly observed in near-coastal areas and is the result of intensified upwelling in the scenario, when Stokes-Coriolis forcing is accounted for. Accounting for sea-state dependent momentum flux results in modified heat exchange at the water-air boundary which consequently leads to warming of surface water compared to control simulation.