42 research outputs found
Scanning probe microscopy study of height-selected Ag/Ge(111) nanomesas driven by quantum size effects
No full textWe present scanning tunnel microscope, noncontact atomic force microscopy, Kelvin probe force microscopy, and low-energy electron diffraction study of the morphological evolution of Ag ultrathin films (0.5-6 ML) grown at 150 K on Ge(111)-c(2×8) substrate. Although the system has been widely studied in the context of quantum confinement effects in the electronic structure of these films, no real-space imaging has been reported so far. Our results demonstrate that upon annealing to room temperature, the Ag film adopts a (111) epitaxy on top of a wetting layer. It has been found that the Ag film adopts a metastable morphology which is determined by a delicate interplay between thermodynamics and the kinetics of interlayer mass transport. The preferential population of a discrete set of the deposit heights at 6, 10, and 12 ML suggests that quantum size effects are indeed active for the Ag/Ge system. Kelvin probe force microscopy indicates that the surface potential depends monotonically on the film thickness and does not show any oscillatory behavior in correspondence to the height change
Leaky atomic traps: upward diffusion of Au from nanopits on ionic crystal surfaces
No full textWe have investigated the formation of gold nanoclusters during submonolayer deposition on atomically flat KBr and RbI (001) ionic-crystal substrates, as well as on substrates patterned with two-dimensional (2D) nanoscale pits produced by electron stimulated desorption. In this way, it is possible to produce atomic steps free from stress and local charging, which are normally considered the reason for enhanced cluster nucleation. Easy nucleation of the Au clusters inside the pits at the lower side of the atomic step edge is not observed, while nucleation of the Au nanoclusters is found to occur preferentially at the upper step edges. Moreover, we observe that gold atoms landing inside the bottom of the pits are able to escape from them by means of thermally activated upward diffusion at the step edges. We propose that the preferential Au nucleation sites at the edges of 2D pits are activated by F centers produced in electronic processes used for nanopatterning of the ionic crystals
Metal nanostructures assembled at semiconductor surfaces studied with high resolution scanning probes
No full textRecent advances of the IFMIF-DONES central instrumentation and control systems engineering design
No full textThe International Fusion Materials Irradiation Facility-DEMO[sbnd]Oriented NEutron Source (IFMIF-DONES) is an accelerator-based neutron source that generates high-energy neutrons via stripping processes by focusing a high-energy deuteron beam on a fast-flowing liquid lithium jet. The neutrons produced are used for the irradiation of materials foreseen in DEMO, thus providing relevant data for the design and licensing of the future fusion reactor. The complexity of such a plant is managed by a central control system that guarantees the safe supervision and control of all operations. This paper summarizes the most recent developments in the design of the IFMIF-DONES plant's Central Instrumentation and Control Systems (CICS) after the completion of the preliminary design phase. In particular, the architecture of two of the main CICS systems (namely, MPS and SCS) is described in detail, focussing on the specific design choices recently proposed. For each system, the current status of design is presented, as well as the existing and future plans for their integration in a unique control framework
Temperature-dependent orientation of self-organized nanopatterns on ion-irradiated
No full textTemperature-dependent self-organized formation of nanoripples on TiO2(110) surfaces irradiated by low-energy Ar+ beams has been investigated by scanning tunnelling microscopy in UHV conditions. Under the experimental conditions employed (2 keV Ar+ and oblique incidence, 75∘ off-normal, T = 120, 300, 620, and 720 K) on the irradiated surface the ripple structure of periodicity ∼10 nm has developed. Interestingly, the orientation of the nanopatterns switches reversibly by 90∘ with the systematic change of the substrate temperature during irradiation. We have demonstrated that formation of the surface nanomorphology is determined by the interplay between the erosion of the monatomic step edges at grazing incidence, anisotropic surface diffusion along the favoured crystallographic orientation and, at elevated temperatures, the diffusion into the bulk of the excess Ti ions. As indicated by density functional theory (DFT) calculations used for modelling the diffusion processes on the ion irradiated TiO2(110), the significant surface mass transport required to form the nanoripples is dominated by the highly mobile Ti atoms diffusing in assistance of O adatoms
The operation of building integrated wind turbines in different weather conditions on the example of the AGH Center of Energy
No full textWzrost zużycia energii w sektorze budownictwa wpływa na poszukiwanie rozwiązań dążących do poprawy efektywności energetycznej w tym zakresie lub uzyskania samowystarczalności energetycznej. Dotowanymi rozwiązaniami są podejścia bazujące na odnawialnych źródłach energii. W celu produkowania energii elektrycznej, na potrzeby własne budynku, wykorzystywane są przede wszystkim panele fotowoltaiczne oraz turbiny wiatrowe. Niniejszy artykuł skupia się na analizie pracy turbiny wiatrowej o poziomej osi obrotu zintegrowanej z budynkiem. Przedmiotowa instalacja zlokalizowana jest na fasadzie budynku Centrum Energetyki AGH oraz skierowana w kierunku północno-zachodnim. W związku z tym turbina pracuje najbardziej efektywnie, gdy wiatr wieje z tego kierunku. Prędkość startowa instalacji wynosi 2,3 m/s, natomiast moc zainstalowana 1,5 kW. Analizowana instalacja posiada możliwość zmiany zarówno kąta łopat, jak i położenia gondoli turbiny względem kierunku wiatru, co poprawia jej wydajność. W artykule omówiono parametry pracy turbiny w zależności od panujących warunków pogodowych. Dla porównania przyjęto okres, w którym nie występowały anomalie pogodowe oraz okres, w którym miał miejsce orkan Grzegorz. Dla tych dwóch przedziałów czasowych (od północy 27.10.2017 do południa 28.10.2017 oraz od północy 29.10.2017 do południa 30.10.2017) zmierzona i porównana została prędkość wiatru, prędkość obrotowa turbiny, moc generowana przez turbinę, a także takie parametry jak: wytwarzany hałas i drgania. Otrzymane wyniki pokazują znaczący wpływ orkanu Grzegorz na parametry pracy instalacji – w tym znaczący wzrost prędkości obrotowej wirnika, a co za tym idzie – siedmiokrotny wzrost średniej mocy generowanej przez turbinę. Z drugiej strony zaobserwowany został również wzrost poziomu hałasu oraz drgań.The rapidly growing energy consumption in the building sector has a significant impact on the efforts to find solutions aimed at improving energy efficiency in this area or even achieving self-sufficiency. One of approaches that can be used is electricity production from renewable energy sources. In order to produce electricity used for the own needs of the building, mainly photovoltaic panels and wind turbines are used. The presented article focuses on the analysis of building an integrated wind turbine with a horizontal axis. The analyzed installation is located on the facade of the AGH Center of Energy building. The installation is oriented in a northwest direction. Therefore, the work of the wind turbine is most efficient when the wind blows from this direction. The installed wind turbine is characterized by the following parameters: the installed capacity amounts to 1.5 kW and the cut-in speed amounts to 2.3 m/s. The user can change the position of the turbine nacelle and set the optimal attack angles to achieve more efficiency. The main purpose of the article is to show the impact of the atmospheric conditions on the work of the installation. The following parameters were analyzed: wind speed and power generation, rotation per minute, vibrations and noise level. The reference period was from October 27–28, 2017, when the atmospheric conditions were normal. The analyzed parameters were compared with the results achieved in the period from October 29–30, 2017, when the wind speed was very high. The aim of presented paper is to show how the wind turbine works in different weather conditions. As it can be expected, the work of the wind turbine is most effective when the wind speed amounts to 5–10 m/s. However, such atmospheric condition are very rare in Poland, thus the wind turbine does not work optimally. It can therefore be stated that the wind turbines integrated with buildings are not a good technical solution in Polish conditions
Dynamika zmian sektorowej struktury zatrudnienia w regionie północno-wschodniej Polski
No full textZdigitalizowano i udostępniono w ramach projektu pn. Rozbudowa otwartych zasobów naukowych Repozytorium Uniwersytetu w Białymstoku – kontynuacja, dofinansowanego z programu „Społeczna odpowiedzialność nauki” Ministra Edukacji i Nauki na podstawie umowy BIBL/SP/0040/2023/01.Uniwersytet w Białymstoku, Wydział EkonomicznyCzajka Z.: Przemiany w strukturze ijakości zatrudnienia na rynku pracy w krajach gospodarki rynkowej. "Praca i Zabezpieczenie Społeczne" 1996, nr 2.Felbur S.: Struktura gospodarki Polski i jej dostosowanie do integracji Z Unią Europejską. "Ekonomista" 1996, nr 4.Goryl A., Walkosz A.: Analiza działowej struktury w Europie, "Wiadomości Statystyczne" 1996, nr 2.Gruszczyńska B., Gruszczyński M.: Metoda analizy stabilności struktury. "Wiadomości Statystyczne" 1988, nr 1.Klamut M.: Ewolucja struktury gospodarczej w krajach wysoko rozwiniętych. Wydawnictwo Akademii Ekonomicznej im. Oskara Langego we Wrocławiu, Wrocław 1995.Kukuła K.: Statystyczna analiza strukturalna i jej zastosowanie w sferze usług produkcyjnych dla rolnictwa, Akademia Ekonomiczna w Krakowie, Kraków 1989.Sadowska-Snarska C.: Przemiany w strukturze zatrudnienia w okresie transformacji, [w:] Bernacki A., Gajewski J. [red.]: Polityka gospodarcza i społeczna państwa a polityka regionalna. Wydział Ekonomiczny UW - Filia w Białymstoku, Katedra Ekonomiki i Organizacji Gospodarstw Rolniczych SGGW, Białystok-Budapeszt-Warszawa 1994.Szumlicz T.: Interpretacje terminologiczne dotyczące zatrudnienia, rynku pracy i bezrobocia. [w:] Kotowska I., Nowakowska B., Oborniak W., Podgrodzka M., Szumlicz T., Zarzycka Z.: Regionalne zróżnicowanie rynku pracy w Polsce w latach 1989-1993. Główny Urząd Statystyczny w Warszawie, Departament Pracy i Dochodów Ludności, Warszawa 1995.Wyżnikiewicz B.: Zmiany strukturalne w gospodarce. Prawidłowości i ograniczenia. PWE, Warszawa 1987.20721
Predicting the growth and survival of probiotic bacteria in fermented carrot juice
No full textCelem pracy było skonstruowanie prognostycznych modeli wzrostu i przeżywalności bakterii potencjalnie probiotycznych w fermentowanym soku marchwiowym. Stwierdzono, że liczba bakterii Lactobacillus acidophilus CH-2, zastosowanych do fermentacji soku marchwiowego, utrzymywała się na wysokim poziomie przez cały badany okres przechowywania. Na podstawie badań empirycznych liczby bakterii potencjalnie probiotycznych w soku marchwiowym, skonstruowano modele prognostyczne, które w zadowalający sposób opisują wzrost i przeżywalność tych bakterii w badanym produkcie. Skonstruowane matematyczne modele wzrostu i przeżywalności bakterii probiotycznych fermentowanego soku marchwiowego umożliwiają szacowanie okresu przydatności do spożycia tego produktu, w zależności od warunków przechowywania.The objective of the research was to construct predictive models of growth and survival of potentially probiotic bacteria in a fermented carrot juice. It was found that the count of Lactobacillus acidophilus CH-2 bacteria used in the fermentation process of carrot juice remained at the same high level during the entire period of storing. On the basis of the empirical investigations into the count of potentially probiotic bacteria in the carrot juice, predictive models were constructed, which satisfactorily described the growth and survival of those bacteria in the product investigated. The constructed mathematical models of growth and survival of probiotic bacteria of the fermented carrot juice make it possible to estimate shelf life of the product studied in relation to its storage conditions
Stereo Evaluation Of ALOS PRISM And IKONOS In Yemen
No full textDLR's Remote Sensing Technology Institute has a long lasting experience in developing spaceborne stereo scanners (MEOSS, MOMS) and the corresponding photogrammetric software systems for stereo evaluation and orthorectification. It takes part in the ESA/JAXA-AO Program to evaluate the performance and potential of the three-line stereo scanner PRISM and the multispectral imaging sensor AVNIR-2 on-board the Japanese satellite ALOS as a principal investigator. The high geometric resolution of PRISM (2.5 m ground sampling distance at nadir) combined with the medium swath width of 35 km has the potential to achieve high quality Digital Elevation Models up to 1:25.000 scale topographic maps for various applications. One of the proposed test sites is located near Sana’a, Yemen, where additionally to the PRISM stereo data also an IKONOS stereo image pair exists, which is used for DEM comparison and performance analysis. The results of this test site are evaluated in cooperation with the Federal Institute for Geosciences and Natural Resources (BGR), Hannover.
The paper gives a report on the generation of digital surface models (DSM) and orthoimages from ALOS/PRISM 3-line stereo data using DLR’s automated stereo processing chain. Ground control points (GCP) of sufficient accuracy are introduced to increase the geometric accuracy of the derived DSM and orthoimages, but as well as evaluations without using GCP shall demonstrate the pointing performance of the ALOS/PRISM system. After the images are prepared for the processing, a matching is performed between the three images in forward, nadir and backward direction using a hierarchical intensity based matching. Sub-pixel accuracy is achieved by a local least squares matching. Blunder reduction is done by thresholds and bi-directional matching. A densification of the tie points is achieved by a region growing algorithm based on local least squares matching. From the obtained tie points, object space coordinates are derived from two different methods to interpolate a regular grid to create a DSM. For the first method Rational Polynomial Coefficients (RPC) are generated for the PRISM images. For the second method a rigorous approach is applied using the exterior and interior orientation parameters as input for the forward intersection. Both methods are compared and the applicability of RPC for PRISM is discussed. Finally the resulting DSM is compared to the DSM generated from the IKONOS stereo pair and evaluated regarding horizontal and vertical accuracy by 3D shift determination between the individual DSM, as well as profile analysis at different terrain steepness.
The possible potential of the derived results is demonstrated for an integrated water resource management in Amran (Yemen), where satellite data of sufficient resolution can provide important information of the changing agrarian areas and resultant water supply. Assessment of potential location for water dams can be derived from high quality DEM. Also terrace cultivation in Yemini mountain valley environment is endangered by mass movements, particularly rock and land slides triggered by flash flood after heavy rainfalls. Susceptibility mapping and monitoring using DEM and land use information from ALOS PRISM and AVNIR-2 data can contribute to these topics
