Rakendusliku mõõteteaduse õppekava magistritööd – Master's theses

Selle kollektsiooni püsiv URIhttps://hdl.handle.net/10062/30310

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Nüüd näidatakse 1 - 20 49

A method for characterization of vibration testing setups
(Tartu Ülikool, 2014) Laizans, Kaspar; Vendt, Riho
ATR-FTIR and multivariate analysis of paints and coating materials
(Tartu Ülikool, 2013) Hayes, Philippa Alice; Leito, Ivo, juhendaja; Vahur, Signe, juhendaja
Building Self-Consistent Scales of Anion Binding by Synthetic Receptor Molecules
(Tartu Ülikool, 2013) Haav, Kristjan; Leito, Ivo, juhendaja
Calibration of hygrometers at fluctuating and transient conditions
(Tartu Ülikool, 2016) Panagiotopoulus, Theofanis; Vilbaste, Martin; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Hygrometers are normally calibrated under stable conditions. Relative humidity values in the climatic chamber fluctuate quite much at medium levels. In this work it was measured how much the relative humidity fluctuation in the climatic chamber affects the calibration of hygrometers. Also the time constants of different hygrometers were measured and the hygrometers were calibrated at drifting relative humidity values. Even though the relative humidity values fluctuate in the climatic chamber at medium levels, this fluctuation has a minor effect in calibration. Even the slowest hygrometers can be calibrated under fluctuating conditions. Under drifting conditions the accuracy of calibration depends on the speed of the drift and the time constant of the hygrometer. The calibration of slowest hygrometers at drift speeds 0.5 %/min and 1 %/min can lead to significant lag errors.
Cellular Uptake of ARC-Based Inhibitors of Protein Kinases
(Tartu Ülikool, 2013) Sinijärv, Hedi; Vaasa, Angela, juhendaja; Uri, Asko, juhendaja
Characterization of a Temperature Measurement System for Use in Vacuum
(Tartu Ülikool, 2020) Akintola, Adeyinka Jimoh; Vendt, Riho; Allik, Mari; Jain, Ayush; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Thermal vacuum tests must be performed to ensure the survivability of the spacecraft during the development and performance validation stages. To carry out these tests, vacuum compatible temperature sensors are placed on different sub-systems of a spacecraft in a vacuum chamber. For the reliability of this test, the temperature sensors to be used need to be calibrated. This work, therefore, aims at improving the temperature measurement system currently used for thermal vacuum testing at the Tartu Observatory, University of Tartu. A suitable vacuum compatible sensor was selected and calibrated in the climatic chamber using the existing measurement system available at the observatory and a new measurement system introduced in this work. Both measurement systems were characterized, and measurement and uncertainty models were designed and estimated for the measurements carried out both in the climatic chamber and in the vacuum chamber.
Characterization of natural sedimentary dolomite and limestone reference materials from Geological Survey of Estonia using LA-ICP-MS
(Tartu Ülikool, 2016) Jansons, Martinš; Paiste, Päärn, juhendaja; Kirsimäe, Kalle, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Sedimentary dolomite (Es-16, Es-18) and limestone (Es-3, Es-14, Es-17) from Geological Survey of Estonia have been used as reference materials in X-ray fluorescence analysis in Estonian laboratories. Homogeneity of these materials was investigated with laser-ablation inductively coupled plasma mass-spectrometry using MACS-3 and NIST612 certified reference materials for calibration. Natural limestone CAL-S from CRPG was analyzed for overall comparison. Potential application of Es’s as micro-analytical reference materials was evaluated by quantification of uncertainty due to inhomogeneity and estimation of homogeneity index. Es-17 and Es-16 were found most homogenous. More homogenous distribution and higher concentrations of Cs and Rb were found in Es-17, Es-3 and Es-16 than in MACS-3. Inhomogenous distribution of rare earth elements was observed in Es-14, Es-18 and Es-17.
Computational estimation of receptor-anion binding in solution
(Tartu Ülikool, 2014) Pung, Astrid; Leito, Ivo
Determination of Amino Acids in Bee Products by Diethyl ethoxymethylenemalonate Derivatization Using LC-ESI-MS/MS
(Tartu Ülikool, 2019) Bùi, Nguyên Kim Ngân; Herodes, Koit; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Amino acid content of honey and royal jelly has been used for the product authentication, geographical and botanical origin evaluation, indication of freshness and nutritional value. In this thesis analytical method was tested and improved for analysis of the concentration of free amino acids in Vietnamese monofloral (Robusta coffee) honey and Royal Jelly by derivatization with diethyl ethoxymethylenemalonate (DEEMM) using liquid chromatography coupled to mass spectrometry (LC-MS/MS). The derivatization proceeds under aqueous conditions and is sufficiently fast reaction for most amino acids. Limits of quantitation at ng g-1 level were achieved for most amino acids. The method has good repeatability and recovery in general. Determined amino acid contents agree, in general, well with literature findings in different honey and royal jelly samples. The differences found may be indicative of botanical/geographical origin of these bee products.
Determination of antibacterials in river water by solid phase extraction using LC -MS/MS
(Tartu Ülikool, 2020) Iftikhar, Waseem Ahmad; Herodes, Koit; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Analytical method was developed for the detection of fluoroquinolones (FQs), sulfonamides and Amphenicol in Emajogi river in Tartu City. The compounds were simultaneously extracted from river water using solid phase extraction (SPE). Identification and quantification was done through Liquid chromatography – tandem mass spectrometry (LC-MS/MS) in selected reaction monitoring (MRM) mode.The recovery of FQs ranged 62% for Enrofloxacin to 76% Marbofloxacin and 68% Florfenicol ,69% sulfamethoxazole. Limit of Quantification ranged from 0.1 ngg-1 for SA’s ,0.6 - 1.5 ngg-1 for FQ’s, and 0.9ngg-1 for FF. The method was developed and valdated for river water analysis of samples from upstream, midpoint and down stream of the WWTP. The method developed may be used for a more in-depth study on the occurence and fate of these commonly used pharmaceuticals in river water bodies.
Development and validation of gamma spectrometric analysis procedure using a high purity Germanium detector
(Tartu Ülikool, 2016) Sanni, Oluwamayowa Sharon; Tkaczyk, Alan, juhendaja; Goronovski, Andrei, juhendaja; Kiisk, Madis, juhendaja; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
A new detection system, broad energy high purity germanium detector with software (Genie 2000 software) was used to develop a gamma spectrometric analysis procedure. LabSOCS as a tool in Genie was needed to perform a standard-free calibration measurement. Validation of analysis procedure was important to know if the procedure is fit for purpose.
Development and validation of UHPLC-MS/MS method for analysis of sedative drugs and their metabolites in blood plasma
(Tartu Ülikool, 2016) Veigure, Ruta; Herodes, Koit; Kipper, Karin; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
In intensive care units, the precise administration of sedative drugs is crucial in order to avoid under- or over sedation – both of which can be very harmful. It is especially important in case of paediatric patients. A highly sensitive simultaneous UHPLC-MS/MS method was developed for the quantification of morphine, morphine-3-β-glucuronide, morphine-6-β-glucuronide, clonidine, midazolam and 1’-hydroximidazolam in human plasma samples. The lowest limit of quantification for all analytes was 50 pg/mL using only 100 μL of blood plasma. Analytes were separated chromatographically using C18 column with weak ion-pairing additive 1,1,1,3,3,3-hexafluoro-2-propanol with pH = 9 (adjusted using ammonium hydroxide) and methanol. Method was fully validated and method was using matrix matched calibration in the range of 0.05-250 ng/mL for all analytes. Within-day accuracy for all analytes remained 87-113 %, but within-day precision remained within 3-11 % for all analytes at all concentration levels over the calibration range. The method will be applied for real patients’ samples in the EU FP7 project CloSed – "Clonidine for Sedation of Paediatric Patients in the Intensive Care Unit”.
Development of a high-throughput method for soil fatty acid derivatization and analysis
(Tartu Ülikool, 2021) Aleihela Yamannalage, Ayesh Piyara Wipulasena; Vahter, Tanel; Herodes, Koit; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
The Bligh and Dyer method of extraction and separation of phospholipid fatty acids (PLFAs) and neutral lipid fatty acids (NLFAs) has been extensively used in soil microbial community studies. A high throughput method of soil fatty acid analysis was developed which involves the extraction of fatty acids, separation of the fatty acids to PLFAs and NLFAs using solid-phase extraction technique, and subjecting the fatty acids to mild alkaline methanolysis prior to analysis using a GC-FID. Where possible stages were modified to be carried on a 96 well plate multi-tier unit, increasing the sample throughput and decreasing the overall consumption of solvents, cost of analysis, and time. The novel high throughput method showed comparable biomass and community characteristics to that of the standard method and thus, could be proposed as a novel method of fatty acid analysis.
Development of foreign body detection methodology in industrial food preparation process
(Tartu Ülikool, 2016) Patel, Sagar Ramanbhai; Tamm, Tarmo; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Several techniques for the detection of the FB in food were studied and the advantages and disadvantages of each technique were analyzed. Among all the available techniques, ultrasound technique was found to be most promising in the detection of FB. The system for the FB detection using ultrasound was based upon pulse echo technique and was analyzed by the means of simulation, using COMSOL multiphysics 5.2 software. The model includes food pipe, transducer and possible FBs inside the liquid food. The applicability of ultrasound to the detection of FB as small as 0.1 mm in radius was established, temperature and frequency dependence was studied. A multiple time shifted transducer scheme was designed to cover maximum area of the food pipe.
Development of Li column chemistry procedure for calcium carbonate material
(Tartu Ülikool, 2021) Zhang, Nanyun; Paiste, Päärn; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
The main objective of the study was to develop a relatively fast and robust column to isolate Li from the matrix components in solutions prepared from carbonate materials. Four parameters, eluent concentration, matrix loading, Li and acid concentration in sample solutions, were used to evaluate the column's efficiency and robustness. The thesis results show that Li and acid concentration in the sample solution do not affect the Li isolation, but the elution range of higher matrix loading will shift to the smaller range. The whole eluting procedure with optimized concentration 0.3 M HCl only takes around 4 hours. The ��7 Li values with uncertainties (2σ) of samples prepared using the developed set-up were highly consistent with the reference values and the comparative measurement.
Development of method for boron determination in basalt fibers
(Tartu Ülikool, 2022) Mamun, Faisal-Al; Paiste, Päärn; Mõtlep, Riho; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
The main objective of the present thesis was to develop a method to determine the boron content of boron doped basalt fibers. Two types of samples were investigated: natural basalt powders doped with H3BO3 were used for method development and the method was applied to basalt fiber samples from two different fiber producers. Na2O2 based alkaline fusion with different sample masses and the use of HCl and HNO3 for dissolution of fusion residues was investigated. The results show that using 10:1 flux to sample ratio and HCl as dissolving acid allows for full digestion of sample and determination of boron content by MP-AES analysis. Results from the analysis of commercial basalt fibers revealed that fibers from one producer, contrary to the suppliers claim, did not contain any boron, highlighting the need for quality check and the development of method to do that.
Development of method for preliminary identification of cyclic dinucleotides in bacterial cultures
(Tartu Ülikool, 2016) Andres, Stanislav; Hartig, Jörg; Herodes, Koit; ; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Cyclic dinucleotides are perspective second messengers in Bacteria. Known compounds of the class play various roles in many processes in bacteria from cell cycle to pathogenesis. In vivo compounds are synthesized with cyclic dinucleotide cyclases and degrade with specific phosphodiesterases. Many of discovered proteins of these classes do not interact with known cyclic dinucleotide compounds, which suggest another compounds of the class may be also in the bacterial cell. In this work a method was developed , based on liquid chromatography coupled mass spectrometry with several columns, which is capable to distinguish possible compound of interest in the bacterial extract based on the chemically synthesized compounds of the class. Method is shown to have LOD lower, than in any method proposed before for single cyclic dinucleotide compound. As a proof of principle, several bacteria reported to produce cyclic diguanylate or cyclic diadenylate were tested. In addition, it was demonstrated that levels of some of cyclic dinucleotides are dependent on growing phase of bacteria.
Effect of soil sample preparation on fatty acid biomarker content
(Tartu Ülikool, 2021) Kasaju, Manju; Vahter, Tanel; Herodes, Koit; Tartu Ülikool. Loodus- ja täppisteaduste valdkond
Different techniques for the pre-treatments were applied at various time frames to evaluate their impact on fatty acid biomarkers content for the soil sampled from Suurmetsa, Põlva County, Estonia, one from the arable field the other from grassland. The fatty acids were extracted by the PLFA method and analysed by using GC-FID. The study included eight bacterial biomarkers (i15:0, a15:0, i16:0, a17:0, 17:0, 10Me17:0 ,10Me18:0, cy19:0),total fungal biomass 18:2ꙍ6,9 and AM fungal biomass by group specific NLFA (16:1ꙍ5). Three pre-treatment methods ( Freezing and Lyophilization, Silica gel, and Hot Air Oven) on four different time frame (0, 8, 24, 48) was carried out. Comparing different pre-treatment methods showed both freezing and lyophilization, and the silica gel method is adequate to identify fatty acid biomarkers content. Still, soil pre-treatment should be done as early as possible to get better results. However, for studying general ecological patterns, whichever approaches, or treatment methods can be chosen.
Electron- vibrational coupling in phycobiliproteins of Acaryochloris marina
(Tartu Ülikool, 2013) Gryliuk, Galyna; Pieper, Jörg, juhendaja
Energy level structure and electron - phonon coupling in the light - harvesting complex II
(Tartu Ülikool, 2014) Artene, Petrica; Pieper, Jörg

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