Magistratūros baigiamajame darbe buvo analizuojamas jūrinio transportinio laivo korpuso korozinis dilimas ir jo priežastys, pateikiami defektacijos metodai, vertinami eksperimentinių matavimų metu gauti rezultatai. Baigiamasis darbas susideda iš teorinės, eksperimentinės ir praktinės dalies. Teorinėje dalyje apžvelgtos laivo korpuso nusidėvėjimo problemos, apžvelgti klasifikacinių bendrovių reikalavimai laivo korpuso būklei, išnagrinėtos laivo korpuso remonto technologijos. Eksperimentinėje dalyje pateiktos balkerio ,,LEDI CHRIS“ korpuso konstrukcijų liekamojo storio matavimo ultragarsiniu stormačiu rezultatai, palyginti matavimų duomenys, gauti laivo korpuso defektacijos tyrimo metu 2002, 2007 ir 2012 m., nustatytos labiausiai korozinio proceso paveiktos laivo konstrukcijos. Praktinėje baigiamojo darbo dalyje buvo atlikti skaičiavimai, siekiant nustatyti laivo korpuso lakštu stipruma po korozijos poveikio ir apskaičiuota tikimybes analize. / The master‘s thesis analyses the causes of the corrosive wear in marine transport ships. It is further followed by the examples of the flaw detection methods and the assessment of the results obtained through experimental measurements. The thesis has theoretical, experimental and practical parts to it. The theoretical part entails the review of the issues related to the depreciation of the ship‘s hull. Moreover, the theory includes the overview of the requirements imposed by the classification society in regards to the condition of the ship‘s hull. The thesis also brings forth the examination of the repair technology that is being used in connection to such issues. The experimental section of the thesis entails the residual thickness measurements of the hull structures obtained through the ultrasonic calipers that were applied on the bunker „LEDI CHRIS“. The comparison of the measurements‘results is also provided, based mainly on the data taken from the flaw detection test that was administered in the years 2002, 2007 and 2012. Additionally, the thesis identifies the structures of the ship that were impacted the most by the process of the corrosion. Last but not least, the practical part of the thesis presents calculations that were conducted in order to determine the durability of the ship‘s hull plating that was affected by the corrosion. The thesis concludes with the probability analysis of the corrosion causes.

<p>The small intestine of the gastrointestinal tract displays a variety of motor patterns involved in the mixing, digestion, and propulsion of luminal content. Ultimately, it is the co-ordinated effort of smooth muscle contraction influenced by neural and myogenic stimulation that facilitate these motor patterns. While neural input from the enteric nervous system (ENS) and slow wave producing activity of the peacemaking interstitial cells of Cajal (ICC) in the myenteric plexus (ICC-MP) are key players in the manipulation of smooth muscle cells, the mechanisms behind the onset the segmentation motor pattern are currently unknown. I have demonstrated with intracellular recordings of electrical activity from circular smooth muscle cells, the same nutrient stimulants used to induce the segmentation motor pattern in whole organ preparations evokes the waxing waning phenomenon of the smooth muscle slow wave. Through the use of continuous wavelet transformation analysis on nutrient induced waxing waning, it was determined that the induction of a rhythmic low frequency component is responsible for the generation of waxing waning. Stimulated low frequency activity after methylene blue mediated elimination of ICC-MP slow wave activity suggested the low frequency component did not originate from the ICC-MP. The hypothesis emerged that the ICC of the deep muscular plexus (ICC-DMP), on the opposite side of the circular muscle thickness to the ICC-MP, were responsible for the low frequency oscillations. ICC-DMP networks in close physical proximity to nerve fibers were found to be under tonic inhibited by nitric oxide, and to respond to substance P stimulation. Both alleviation of the inhibition and stimulus by tachykinergic neurotransmission induced the low frequency component and waxing waning. The ENS and myogenic pacemakers play an important role in stimulating the segmentation motor pattern. ICC-DMP are the pacemakers responsible for generation of the low frequency component involved in waxing waning and segmentation.</p> / Master of Science (MSc)