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.

A Review of the Synthesis and Photoluminescence Properties of Hybrid ZnO and Carbon Nanomaterials

Abstract: Photoluminescent ZnO carbon nanomaterials are an emerging class of nanomaterials with unique optical properties. They each, ZnO and carbon nanomaterials, have an advantage of being nontoxic and environmentally friendly. Their cost-effective production methods along with simple synthesis routes are also of interest. Moreover, ZnO presents photoluminescence emission in the UV and visible region depending on the synthesis routes, shape, size, deep level, and surface defects. When combined with carbon nanomaterials, modification of surface defects in ZnO allows tuning of these photoluminescence properties to produce, for example, white light. Moreover, efficient energy transfer from the ZnO to carbon nanostructures makes them suitable candidates not only in energy harvesting applications but also in biosensors, photodetectors, and low temperature thermal imaging. This work reviews the synthesis and photoluminescence properties of 3 carbon allotropes: carbon quantum or nanodots, graphene, and carbon nanotubes when hybridized with ZnO nanostructures. Various synthesis routes for the hybrid materials with different morphologies of ZnO are presented. Moreover, differences in photoluminescence emission when combining ZnO with each of the three different allotropes are analysed.

Molecularly Imprinted Polymer Integrated with a Surface Acoustic Wave Technique for Detection of Sulfamethizole.

Abstract: The synergistic effect of combining molecular imprinting and surface acoustic wave (SAW) technologies for the selective and label-free detection of sulfamethizole as a model antibiotic in aqueous environment was demonstrated. A molecularly imprinted polymer (MIP) for sulfamethizole (SMZ) selective recognition was prepared in the form of a homogeneous thin film on the sensing surfaces of SAW chip by oxidative electropolymerization of m-phenylenediamine (mPD) in the presence of SMZ, acting as a template. Special attention was paid to the rational selection of the functional monomer using computational and spectroscopic approaches. SMZ template incorporation and its subsequent release from the polymer was supported by IR microscopic measurements. Precise control of the thicknesses of the SMZ-MIP and respective nonimprinted reference films (NIP) was achieved by correlating the electrical charge dosage during electrodeposition with spectroscopic ellipsometry measurements in order to ensure accurate interpretat...

A Fuzzy Logic Model to Describe the Cyanobacteria Nodularia spumigena Blooms in the Gulf of Finland, Baltic Sea

Abstract: A fuzzy logic model to describe the seasonal evolution of Nodularia spumigena blooms in the Gulf of Finland was built and calibrated on the basis of monitoring data. The model includes three phosphate sources: excess phosphate after the annual spring bloom and parameterised phosphate transport to the upper mixed layer by turbulent mixing and upwelling events. Surface layer temperature and wind mixing form the physical conditions controlling the growth of N. spumigena. Model simulations revealed that phosphate input caused by turbulent mixing and upwelling have to be taken into account to achieve the best fit with observed data. Testing the fuzzy model for early prediction of maximum N. spumigena biomass about a month before the usual occurrence of blooms, gave good results. The potential use of the model for prediction of bloom risk at a certain location along the Estonian or Finnish coast was tested. The bloom transport velocities used in the fuzzy model were pre-calculated by a 3D numerical circulation model for different wind regimes.