A heterocyclic aromatic rigid-rod polymer poly-p-phenylene-benzobisoxazole (PBO) was applied as the opto-electronic layer¡Fand a conducting material of poly(3,4-ethylenedioxythio-phene):poly(4-styrenesulfonic acid) (PEDOT: PSS) was used as the hole transport layer. Aluminum (Al) and indium tin oxide (ITO) were served as device cathode and anode¡Arespectively, fabricated into a bi-layer structure of ITO/PEDOT:PSS/PBO/Al for electrical and luminescence responses. This research demonstrated an increase of current density and a decrease of threshold voltage with a decrease of PBO layer thickness from 90 nm to 27 nm to facilitate electron tunneling and electron-hole recombination. With a lower spin coating speed, polymer chain would aggregate and inter-penetrate resulted in red-shift of electroluminescence (EL) emission spectrum. Furthermore, micro-cavity effect might influence EL spectrum by varying layer thickness. Modulation of PBO layer thickness led to tunable EL emission color. It was also demonstrated that an increase of current density and a slightly decrease of threshold voltage with a PEDOT:PSS film thickness changing from 96 nm to 17 nm at a constant PBO layer thickness of 90 nm. Micro-cavity effect thus influenced EL emission for a tunable emission color. Photolithography was applied to obtain ITO substrate of grating depth of periodic variation and then coated with a PEDOT:PSS leading to a grated PEDOT:PSS layer of periodic thickness. This led to ITO/PEDOT:PSS/PBO/Al device showing broadened EL emission spectra.

<p>Measurements of film mass flow rate for annular, diabatic steam-water flow in tubes are presented. The measurements were carried out with four axial power distributions and at several axial positions at conditions typical for boiling water reactors, i.e. 7 MPa pressure and total mass flux in a range from 750 to 1750 kg/m2s. The results show that the influence of the axial power distribution on the dryout power corresponds to a consistent tendency in the film flow rate and that the film tends to zero when dryout is approached. Furthermore it is demonstrated that two selected phenomenological models of annular flow well predict the present data. A model for additional entrainment due to boiling is shown to degrade the predictions.</p>

The Western U.S. has experienced widespread extension during the past 10’s of millions of years, largely within the Basin and Range and Rio Grande Rift provinces. Tomography results from previous studies revealed narrow fast seismic velocity anomalies in the mantle on either side of the Rio Grande Rift as well as at the western edge of the Colorado Plateau. The fast mantle anomalies have been interpreted as down-welling that is part of small scale mantle convection at the edge of extending provinces. It was also found that crust was thicker than average ab¬¬ove the possible mantle down-welling, indicating that mantle dynamics may influence crustal flow. We present results from P/S conversion receiver functions using SIEDCAR (Seismic Investigation of Edge Driven Convection Associated with the Rio Grande Rift) data to determine crustal and lithospheric structure beneath the east flank of the Rio Grande Rift. Crustal and lithosphere thickness are estimated using P-to-S and S-to-P receiver functions respectively. Receiver function migration methods were applied to produce images of the crust and lithosphere. The results show variable crustal thickness through the region with an average thickness of 45 km. The crust achieves its maximum thickness of 60km at 105W longitude, between 33.5N and 32.2N latitude. This observation confirms previous receiver function results from Wilson et al, 2005. Body wave tomography (Rocket, 2011; Schmandt and Humphreys, 2010) using similar data to what we used for the receiver function analysis, shows mantle downwelling closely associated with the thickened crust. We believe that the thickened crust might be due to lower crustal flow associated with mantle downwelling or mantle delamination at the edge of the Rio Grande Rift. In this model the sinking mantle pulls the crust downward causing a pressure gradient within the crust thus causing the flow. Our S-P images show signal from the lithosphere-asthenosphere boundary (LAB) with an average LAB thickness of 100 km but with a sharp transition at about 1050 W from 75 km to over 100 km. The region with abnormally thick crust overlies a region where the lithosphere appears to have a break. We interpret our results as showing that lower lithosphere has and is delaminating near the edge of the Great Plains accompanied by lower crustal flow in some places determined by lower crustal viscosity. / text

Water is essential to life on Earth. Since water exists in all three phases (solid, liquid, and gas) on Earth, it exists in various reservoirs throughout the planet that compose the hydrologic cycle, and its movement through these reservoirs requires energy. Thus, water is a key component of the energy balance of the Earth. Despite its importance, its representation in modeling and dataset generation is problematic. Here, the depiction of three phenomena, ocean surface turbulent fluxes, humidity inversions, and groundwater, are assessed, and suggestions for improvements of their representations are made. First, ocean surface turbulent fluxes, including those of moisture (latent heat flux), heat (sensible heat flux), and momentum (wind stress), from reanalysis, satellite-derived, and combined products which are commonly used to produce climatologies and to evaluate global climate models are compared to in situ observations from ship cruises to ascertain which products are the least problematic. The National Aeronautics and Space Administration’s reanalysis, the Modern Era Retrospective Analysis for Research and Applications, is the least problematic for all three fluxes, while a couple of others are the least problematic for only one of the three fluxes. Also, the product biases are disaggregated into uncertainties from the grid cell mean quantities, or bulk variables, used plus the residual uncertainties which includes the algorithm uncertainties due to the parameterization used to relate the small-scale turbulent processes to the large-scale bulk variables. The latter contribute the most to the majority of product latent heat fluxes, while both uncertainties can contribute the most to product sensible heat fluxes and wind stress. Thus, both algorithms and bulk variables need to be improved in ocean surface flux datasets. Second, humidity inversion climatologies in five reanalyses are evaluated. Humidity inversions, similar to its thermal counterpart, are layers in which specific humidity increases with height rather than the usual decrease with height. These are especially persistent in the polar regions in autumn and winter. However, Arctic inversions are the strongest in summer corresponding to the time of year that low cloud cover is the highest. Comparing the reanalysis inversions to radiosonde observations reveals some problems with the realization of humidity inversions in reanalyses including the misrepresentation of the diurnal cycle and of the overproduction of inversions in areas outside the polar regions. Finally, the simulation of groundwater in the Community Land Model (CLM) as used in the Community Earth System Model is made more realistic by including variable soil thickness. Because the bottom of the model soil column is placed at effectively bedrock, the unconfined aquifer model currently used in CLM is removed and a zero bottom water flux is put in place. The removal of the unconfined aquifer allows the simulation of groundwater to not be treated separately from soil moisture. The model is most affected where the number of soil layers is reduced from the original constant 10 layers and largely unaffected where the number of soil layers is increased except for baseflow where the mean annual range in rainfall is large.

Engine development is now driven by cost, performance, governmental regulations and customer demands. Several of the requirements have tribological associations. Tribological improvements which consist in lowering friction and improving wear resistance in engines, will play a major role to increase reliability and life cycle. The components studied here are parts of the valvetrain mechanism of heavy-duty Diesel engines. The injection cam is one of the most problematic parts of the camshaft, as it is subjected to high pressures from the fuel injector. Lubrication is of significant importance in the prevention of cam failure caused by wear. However, the satisfactory lubrication of the cam and roller contact has proved to be one of the most difficult tribological design challenges to take up. For a lubricated contact, the degree of separation between surfaces has a very strong influence on the type and amount of wear. This degree of separation is termed as specific film thickness ; its value provides a measure of the severity of asperities interaction in the lubricated contact. In this report, attention is drawn on the evaluation of oil film thickness in the cam-roller contact, in order to predict regimes of lubrication and thus to identify the probable wear zones of the injection cam. Then, confrontation with experimental results is performed(observation of worn cam surfaces). Future work to achieve is to discover the influence of the different parameters on oil film thickness, by performing a multivariate analysis. The next step will focus on modelling the wear of injection cams, and finally establishing quantified correlations between wear and specific film thickness.

No description available.

Darbe analizuojami viengyslių varinių ir aliumininių elektros laidų izoliacijos nuėmimo technologiniai režimai, kai šie laidai utilizuojami terminiu būdu patobulinta dviejų besisukančių būgnų mašina. Eksperimentas buvo atliekamas Vilniaus Gedimino technikos universiteto Mašinų ir technologijų laboratorijoje. Šio darbo pagrindinis tikslas – nustatyti optimaliausius elektros laidų izoliacijos sluoksnio nuėmimo, nepažeidžiant laidininko vielos, režimus priklausomai nuo laidų storio dydžio. Bandymo metu gauti rezultatai būtų naudingi smulkioms laidų gamybos, taupant ribuotas žaliavas, atliekų perdirbimo, elektros įrenginių remonto ir gamybos įmonėms efektyviau išnaudoti tokias mašinas. / This work presents results of investigations of technological conditions of removal of plastic insulator from single-core cables, when the cable placed between two rotating rolls and surface of the one roll is heated below the melting temperature of thermoplastic insulator. Experiments were carried out in the Laboratory of machines and technologies of Vilnius Gediminas technical university. The main aim of investigations was to obtain the optimal insulator removal conditions (speed of the roll and temperature of the hot roll) for different core diameter cables. The experimental research results are presented as the optimal peripheral velocity of rolls (or cable speed) required to complete removal of polyvinylchloride insulator from the conductor versus the thickness of copper and aluminum conductor of the single-core cable. The results of investigations can be interesting for small cable manufacturers, waste utilization enterprises and electric equipment repair workshops.

Cornea is a part of the optical system of the eye, the condition of which is directly related with the eyesight and its quality. Due to the increasing popularity of the correction of refraction defects with the help of excimer laser, central cornea thickness acquires higher prognostic significance for the determination of the success of the operation and probable post-surgical complications. The objective of the survey is to measure the central corneal thickness of adult residents in Lithuania and the relevant factors having impact on it. In total 1650 residents of Lithuania in the age from 18 to 89 years of age were tested. The survey was carried out in the urban and regional primary health care institutions of the 10 counties of Lithuania and at the Centre of Eye Diseases of the Vilnius University Hospital Santariškių klinikos. The average central corneal thickness of men and women in Lithuania was defined in the survey. It was observed that central corneal thickness is neither conditioned by the gender, height or weight of an individual, nor by the eye refraction or the number and the size of corneal endothelia cells. The thickest cornea was observed in persons under 40 years of age, whereas it becomes thinner each decade from 2 to 8 µm after forty. It was identified in the survey that the thicker the cornea is - the smaller is its curvature. On the basis of the survey a table of central corneal thickness was developed for doctors ophthalmologists to be used in their... [to full text] / Ragena – tai akies optinės sistemos dalis, nuo kurios būklės tiesiogiai priklauso regėjimas ir jo kokybė. Populiarėjant refrakcijos ydų korekcijai eksimeriniu lazeriu, ragenos centrinės dalies storis turi vis didesnę prognostinę reikšmę operacijos sėkmės bei pooperacinių komplikacijų galimybės nustatymui. Darbo tikslas – nustatyti Lietuvos suaugusių gyventojų ragenos centrinės dalies storį bei jį veikiančius veiksnius. Ištirta 1650 Lietuvos gyventojų nuo 18 iki 89 metų amžiaus.Tyrimas vykdytas 10 Lietuvos apskričių miestų ir rajonų pirminėse sveikatos priežiūros įstaigose, bei VUL Santariškių klinikos Akių ligų centre. Tyrimo metu nustatytas Lietuvoje gyvenančių vyrų ir moterų vidutinis ragenos centrinės dalies storis. Nustatyta, kad ragenos centrinės dalies storis nepriklauso nuo žmogaus lyties, ūgio, svorio, bei akių refrakcijos ir ragenos endotelio ląstelių skaičiaus ir dydžio. Storiausia ragena nustatoma iki 40 metų amžiaus, vyresniems nei 40 metų ji plonėja kas dešimtmetį nuo 2 iki 8 µm. Nustatyta, kad kuo storesnė ragena, tuo jos gaubtumas yra mažesnis. Tyrimo pagrindu sukurta skirtingo amžiaus žmonių ragenos centrinės dalies storio lentelė, kuria savo praktiniame darbe galės naudotis visi gydytojai oftalmologai.

Ragena – tai akies optinės sistemos dalis, nuo kurios būklės tiesiogiai priklauso regėjimas ir jo kokybė. Populiarėjant refrakcijos ydų korekcijai eksimeriniu lazeriu, ragenos centrinės dalies storis turi vis didesnę prognostinę reikšmę operacijos sėkmės bei pooperacinių komplikacijų galimybės nustatymui. Darbo tikslas – nustatyti Lietuvos suaugusių gyventojų ragenos centrinės dalies storį bei jį veikiančius veiksnius. Ištirta 1650 Lietuvos gyventojų nuo 18 iki 89 metų amžiaus.Tyrimas vykdytas 10 Lietuvos apskričių miestų ir rajonų pirminėse sveikatos priežiūros įstaigose, bei VUL Santariškių klinikos Akių ligų centre. Tyrimo metu nustatytas Lietuvoje gyvenančių vyrų ir moterų vidutinis ragenos centrinės dalies storis. Nustatyta, kad ragenos centrinės dalies storis nepriklauso nuo žmogaus lyties, ūgio, svorio, bei akių refrakcijos ir ragenos endotelio ląstelių skaičiaus ir dydžio. Storiausia ragena nustatoma iki 40 metų amžiaus, vyresniems nei 40 metų ji plonėja kas dešimtmetį nuo 2 iki 8 µm. Nustatyta, kad kuo storesnė ragena, tuo jos gaubtumas yra mažesnis. Tyrimo pagrindu sukurta skirtingo amžiaus žmonių ragenos centrinės dalies storio lentelė, kuria savo praktiniame darbe galės naudotis visi gydytojai oftalmologai. / Cornea is a part of the optical system of the eye, the condition of which is directly related with the eyesight and its quality. Due to the increasing popularity of the correction of refraction defects with the help of excimer laser, central cornea thickness acquires higher prognostic significance for the determination of the success of the operation and probable post-surgical complications. The objective of the survey is to measure the central corneal thickness of adult residents in Lithuania and the relevant factors having impact on it. In total 1650 residents of Lithuania in the age from 18 to 89 years of age were tested. The survey was carried out in the urban and regional primary health care institutions of the 10 counties of Lithuania and at the Centre of Eye Diseases of the Vilnius University Hospital Santariškių klinikos. The average central corneal thickness of men and women in Lithuania was defined in the survey. It was observed that central corneal thickness is neither conditioned by the gender, height or weight of an individual, nor by the eye refraction or the number and the size of corneal endothelia cells. The thickest cornea was observed in persons under 40 years of age, whereas it becomes thinner each decade from 2 to 8 µm after forty. It was identified in the survey that the thicker the cornea is - the smaller is its curvature. On the basis of the survey a table of central corneal thickness was developed for doctors ophthalmologists to be used in their... [to full text]

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.