Baigiamajame darbe analizuojamas sapropelio kaip rišiklio panaudojimas termoizoliacinių plokščių gamyboje. Kompozicines medžiagas užpildant spygliuočių medžių pjuvenomis. Šiems tyrimams buvo pasirinktas užpelkėjusio Dobilios ežero esančio Kauno rajone sapropelis. Buvo Pagaminta speciali forma bandiniams formuoti. Formuojami bandiniai turėjo skirtinga sapropelio kiekį 200g formavimo masėje. Pasirinktas sapropelio kiekis bandinyje kito nuo 20 iki 35%. Sapropelio ir pjuvenų mišinys formoje buvo slegiamas 0,5; 1,5; 2,5; 3,5; 4,5 MPa slėgiu. Buvo ištirtas šių bandinių atsparumas gniuždymui, atsparumas lenkimui bei nustatytas bandinių tankis ir šiluminis laidumas. Taip pat buvo nustatyta šiluminio laidžio koeficiento priklausomybė nuo sapropelio kiekio bandinyje. / This Master Thesis analyses the appliance of sapropel as a binder in a heat insulation plate production. As a rest composing material sawdust of conifer was used. For the research was chosen a silt of a waterlogged lake Dobilė, located in Kaunas region. Samples were formed with a specially for the research made form. Every sample had a different quantity of sapropel in a forming mass of 200g. A chosen quantity of sapropel in a sample variated from 20 to 35% percents. The mix of sapropel and sawdust in a form was pressed by 0.5, 1.5, 2.5, 3.5, 4.5 MPa pressure. During the research was analyzed sample resistance to compression and flexure, estimated sample density and thermal conductivity. Thermal conductivity dependence on the quantity of sapropel in a sample was estimated as well.

Baigiamajame darbe analizuojamas sapropelio kaip rišiklio panaudojimas termoizoliacinių sapropelio-šiaudų plokščių gamyboje. Šiems tyrimams buvo pasirinktas užpelkėjusio Dobilios ežero, esančio Kauno rajone, organinis sapropelis. Bandiniai buvo gaminami su skirtingu sapropelio-šiaudų kiekiu juose ir formuojami specialioje tyrimams pagamintoje formoje. Suformuotų bandinių masė buvo apie 130g. Suformuotų bandinių sapropelio kiekis kito nuo 15% iki 35%. Presavimo slėgis buvo 0,25; 0,5; 0,75; 1,0 MPa. Buvo nustatomas tiriamų bandinių, tankis atsparumas lenkimui ir gniuždymui, taip pat apskaičiuojamas šiluminis laidumas. Raktiniai žodžiai: sapropelis, šiaudai, plokštelės, lenkimas, gniuždymas, stipris. / This Master Thesis analyses the appliance of sapropel as a binder in a heat insulation plate production. For the research was chosen a silt of a waterlogged lake Dobilė, located in Kaunas region. All samples were formed with specially made form for research. Every sample had different quantity of sapropel and strawdust. Forming weight of samples were approx 130g. A chosen quantity of sapropel variated from 15 to 35 percents in a sample. The mix of sapropel and strawdust in a form was pressed by 0,25; 0,5; 0,75; 1,0 MPa pressure. During the research samples were analysed their resistance to compression and flexure, estimated sample density and thermal conductivity. Keywords: binder, sapropel, plate, compression, flexure, straw.

Pirmoje šio darbo dalyje pristatomi temperatūros pasiskirstymo aktyviojoje lazerio terpėje kompiuterinio modeliavimo rezultatai. Skaičiavimai atlikti dviem aktyviosios terpės geometrijoms – plono disko ir plokščiojo kompozitinio elemento. Apžvelgiama skirtingų aktyvios terpės ir kaupinimo parametrų įtaka temperatūros pasiskirstymui. Antroje darbo dalyje pristatomi lazerio pluošto bangos fronto iškraipymų, atsirandančių dėl nevienodo temperatūros pasiskirstymo aktyvioje terpėje ir paviršiaus deformacijų, skaičiavimo rezultatai. / This work presents results of numerical simulation of temperature distribution inside laser active medium. Calculations were performed for two different active medium geometries. First one thin disk geometry and second - composite slab. Influence of different pump and active medium parameters on temperature distribution are presented. Second part of this work presents results of wave front aberrations calculations. Those aberrations were resulted by irregular temperature distribution and surface deformations.

One of the main problems in neurosurgery is knowledge about human brain. It's very important to see the whole brain with its critical neurostructures in virtual reality. This document is about three dimensional human brain visualization strategies. Review most recently used three dimensional objects building strategies from two dimensional medical MRI images. This task was split into 4 significant problems: image segmentation, point-sets correspondence, image registration and its frequently used transformation functions with image matching measurements. All these problems were addressed reader to show most recently used algorithms with advantages and disadvantages. Atlas types, patterns and maps survey was introduced with widely popular brain model coordinate systems. In order to find a better correspondence between two point sets it was modeled a new robust and accurate Overhauser spline points location optimization algorithm. Instead of deletion outlier points from overloaded point set, this algorithm generates more points in other set at optimized points locations. Determination of an accurate point location and choosing the correct transformation function are the key steps in registration process. Whereas registration is vital task in precise human brain visualization for neurosurgeries at preoperative and intraoperative process.