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Publikacje z roku 2012
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Seasonal changes in organotin compounds in water and sediment samples from the semi-closed Port of Gdynia
- Barbara Radke
- Andrzej Wasik
- Linda L. Jewell
- Stuart Piketh
- Urszula Pęczek
- Jacek Namieśnik
The effect of seasonal changes on the distribution of organotin compounds (OTC) in the sediments and seawaterfrom the docks of the Port of Gdynia was investigated. Sediment and seawater samples were collectedfrom four industrial docks in February (winter) and June (summer) in 2009. The samples were analyzed forbutyltin, phenyltin, octyltin, and tricyclohexyltin (total of 9 OTC derivatives). The fine fraction (b0.063 mm)accumulated the highest concentration of OTC, although it was not the dominant fraction in the sedimentsamples from the Port of Gdynia. The average concentration of TBT, DBT and MBT in collected sampleswere as follows: 4400; 2188; 730 ng cation g−1 d.w. (February) 3638; 1590; 474 ng cation g−1 d.w.(June) in the fine sediment samples, 2805; 1266; 485 ng cation g−1 d.w. (February) in b2.00 mm sedimentfractions and 118.6; 39.2; 25.3 ng cation L−1 (February) and 46.5; 12.6; 8.2 ng cation L−1 (June) in thewater samples. Higher concentrations of butyltin derivatives (BT) were observed in samples collected inFebruary than in those collected in June. Seasonal changes in BT correlate well with changes in the waterpH and concentrations of organic matter and can be attributed to sorption/desorption to sediments, photodegradation and biodegradation. Although the Port of Gdynia does not represent the natural features ofa marine environment, seasonal variations recorded in the pH values as well as BT, organic carbon and biogenicelement concentrations seem to be influenced by temperature and microbial activity.
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Secure transmission of visual image in the VTS system using fingerprinting
- Bartosz Czaplewski
- Krzysztof Czaplewski
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Security and Anonymity in Agent Systems
- Rafał Leszczyna
- Igor Kotenko
Many agent systems have been developed and suggested for commercial application. However, in spite of the significant potential offered by the agent paradigm, the lack of such important properties as security, anonymity and untracebility especially in open dynamical environment, such as the Internet, has blocked the active implementation of agent technologies. Protecting agent systems poses a more demanding challenge comparing to traditional environments. Apart of all the threats which face the latter, there are attacks specific to agent environments. The chapter considers issues of agent security, anonymity and untracebility and outlines the main threats to agent systems and existing protection methods.
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Security Mechanisms in the Comcute System
- Piotr Szpryngier
The aim of this paper is pointing out the basic security problems and mechanisms in the Comcute system - maintenance system of large computing power in the face of critical crisis. Moreover security mechanism and tools useful to apply in laboratory model as well as target version of the Comcute system are presented.
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Seeding enhancement for microcrystaline diamond layers growth on non-diamond substrates
- Łukasz Gołuński
- Michał Sobaszek
- Mateusz Gardas
The present paper gives an overview on the possible methods of seeding substrates for diamond layers growth. Diamond in reason of his properties is very desirable material in microelectronic, biomedical and waste treatment sensors. Microcrystalline diamond for these applications must be grown on silicon substrate in microwave plasma assisted chemical vapor deposition (MPACVD). To grow diamond on non-diamond surface pre-growth seeding of the substrate surface is necessary. For MPACVD growth exists several methods of silicon seeding. To find the most effective seeding technique for diamond nucleation mechanical scratching by diamond nanopowder, diamond slurry in water or methanol solution and bias enhanced nucleation (BEN) methods were compared. Microcrystaline thin diamond layers were grown on seeded surfaces in microwave plasma using hydrogen-methane gas mixture. Investigation of growth ration and layer composition was made by Raman spectroscopy and scanning electron microscopy (SEM). Thickness homogeneity of layer and also sp3/sp2 ratio was particularly studied. Results showed that most efficient seeding technique is sonication in nandodiamond powder solution combined with in situ BEN growth enhancement. It can be used in future to preapering good quality doped diamonds which can be used as a semiconductors.
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Seiberg-Witten invariants the topological degree and wall crossing formula
- Maciej Starostka
Following S. Bauer and M. Furuta we investigate finite dimensional approximations of a monopole map in the case b 1 = 0. We define a certain topological degree which is exactly equal to the Seiberg-Witten invariant. Using homotopy invariance of the topological degree a simple proof of the wall crossing formula is derived.
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Selected design and construction aspects of supercritical steam generators for high temperature reactors = Wybrane aspekty konstrukcyjne i projektowe generatorów pary nadkrytycznej ogrzewanych z reaktorów wysokotemperaturowych
- Mariusz Przybylski
- Jerzy Głuch
W artykule zaprezentowano uwarunkowania projektowe i konstrukcyjne nadkrytycznego generatora pary (jednoprzepływowego) wykorzystującego do ogrzewania hel z reaktorów HTR i VHTR. Wymiennik helikoidalny jest preferowany dla zwiększenia wymiany ciepła i zwartości. Badano własności czynników wymieniających ciepło z parą w obszarach przy- i nadkrytycznych. Analizowano korelacje, aby wybrać najbardziej wiarygodne. Przedyskutowano najbardziej krytyczne aspekty tego projektu. Obok aspektów konstrukcyjnych brano pod uwagę problemy obsługi, diagnostyki i bezpieczeństwa. S u m m a r y Article presents design and construction considerations on supercritical (once-through) steam generator using HTR and VHTR cores as heat source. Helical-coil steam generators are preferred over other types of design thanks to their increased heat transfer rate and compactness. Applicable modernised Rankine cycle and changes in thermo-physical parameters of water in the neighbourhood of critical and pseudo-critical points are examined. Correlations determining heat transfer coefficient are analysed in order to select the most applicable among them. Critical design aspects of such a supercritical nuclear steam supply system are discussed. Beyond design and construction considerations, safety, service capability and diagnostics matters are also are raised.
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Selected elements of the methodology and method of designing amphibious flood rescue vehicles
- Mateusz Gerigk
- Mirosław Gerigk
- Zbigniew Burciu
The methodology of designing amphibious flood rescue vehicles at the preliminary stage of the design process has been presented. The study has been focused on the properties of such vehicles when afloat, with their on-land behaviour and performance characteristics having been left aside. In the study, a general assumption has been made that the amphibious flood rescue vehicles should be designed as, above all, watercraft that additionally can be driven on public roads and in off-road conditions. In the introduction, the solutions currently applied in the field of flood rescue transport facilities in Poland have been briefly defined. This has been followed by description of the methodology of designing amphibious flood rescue vehicles, supplemented with presentation of elements of the method of designing such vehicles that is based, firstly, on the assessment of vehicle performance and behaviour when afloat and, secondly, on the assessment of accident risk. The final part of this paper includes some remarks about modelling the shape of the hull of a modern amphibious flood rescue vehicle at the preliminary stage of designing such a vehicle. The methodology has been worked out with bearing in mind the planned further publications that would deal with computational models used for the designing of amphibious flood rescue vehicles.
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Selected problems of stability of thin-walled columns with bisymmetric open cross-section
- Czesław Szymczak
Praca dotyczy problemów stateczności osiowo ściskanych prętów o bisymetrycznym przekroju otwartym. Badano wpływ nieliniowości materiału pręta oraz wstępnego zakrzywienia osi na wyboczenie skrętne oraz początkową ścieżkę pokrytyczną. Na przykładach numerycznych wykazano, że w pewnych przypadkach stateczny, symetryczny punkt może zmienić się na symetryczny ale niestateczny, co oznacza możliwość redukcji siły krytycznej.
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Selection of drive engines for dredge pumps
- Damian Bocheński
This paper presents the principles of selecting drive engines for dredge pumps, formulated by this author. In order to formulate them influence of drive engines on dredge pump characteristics and dredger effectiveness, have been analyzed. Also, an analysis of results of the author's operational investigations concerning energy consumption and parameters of excavated soil transport on board dredgers has been performed.
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Selections and approximations of convex-valued equivariant mappings
- Zdzisław Dzedzej
- Wojciech Kryszewski
Udowodniono szereg twierdzeń o współzmienniczych selekcjach i aproksymacjach ciągłych, mierzalnych i typu Caratheodory'ego dla odwzorowań G-współzmienniczych o wartościach wypukłych, gdzie G jest grupą zwartą Liego. Tw. typu Michaela, Celliny, Browdera, Kuratowskiego-Ryll-Nardzewskiego, Castaing itd.
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Self Organizing Maps for Visualization of Categories
- Julian Szymański
- Włodzisław Duch
Visualization of Wikipedia categories using Self Organizing Mapsshows an overview of categories and their relations, helping to narrow down search domains. Selecting particular neurons this approach enables retrieval of conceptually similar categories. Evaluation of neural activations indicates that they form coherent patterns that may be useful for building user interfaces for navigation over category structures.
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Self-testing of analog parts of mixed-signal electronic microsystems based on multiple sampling of time responses
- Zbigniew Czaja
W artykule przedstawiono nowe podejście samo-testowania toru analogowego zakończonego przetwornikiem A/C w mieszanych sygnałowo elektronicznych systemach wbudowanych sterowanych mikrokontrolerami. Bazuje ono na nowej metodzie diagnostycznej opartej na przekształceniu transformującym zbiór próbek odpowiedzi czasowej układu badanego na pobudzenie impulsem prostokątnym na rodzinę krzywych identyfikacyjnych umieszczonych w przestrzeni pomiarowej. Metoda może być użyta do detekcji i lokalizacji pojedynczych uszkodzeń parametrycznych elementów biernych układu ananlogowego. Do konwersji wyników pomiarowych do postaci wymaganej przez algorytmy detekcji i lokalizacji uszkodzeń oraz do tworzenia słownika uszkodzeń użyto zmodyfikowanych wzorów na DFT.
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Semicrystalline Polyesters Based on a Novel Renewable Building Block
- Jing Wu
- Pieter Eduard
- Shanmugam Thiyagarajan
- Lidia Jasińska-Walc
- Artur Rozanski
- CéLIA Fonseca Guerra
- Bart A. J. Noordover
- Jacco Van Haveren
- Cor E. Koning
Isohexides, like e.g. isosorbide, are well-known carbohydrate-based rigid diols which are capable of dramatically increasing the glass transition temperature of polyesters. However, their relatively low reactivity has thus far hampered large-scale industrial applications in the polymer field. Recently, with the aim to increase reactivity while at the same time retain rigidity, we have developed a new isoidide dicarboxylic acid (IIDCA) by transforming the secondary hydroxyls into carboxylate functionalities. Here we report the first polymers based on IIDCA and linear α,ω-diols. The novel polyesters were obtained via melt polymerization and exhibited weight-average molecular weights in the range of 13 000-34 000 g/mol and polydispersities close to 2.0. NMR analyses showed that the exo-exo configuration of the isoidide dicarboxylate units was preserved during synthesis. Both differential scanning calorimetry and wide-angle X-ray diffraction analyses showed that the IIDCA polyesters are semicrystalline materials. A systematic study on structure-thermal properties relations among relevant series of polyesters, such as isomeric polymers based on isoidide, revealed several interesting differences in melting and glass transition temperatures, which are thought to be related to variations in chain packing and free volume.
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Sensitive determination of isoprostanes in exhaled breath condensate samples with use of liquid chromatography-tandem mass spectrometry
- Monika Janicka
- Paweł Kubica
- Agata Kot-Wasik
- Jacek Kot
- Jacek Namieśnik
Oxidative stress is the hallmark of various inflammatory lung diseases. Increased concentrations of reactive oxygen species in the lungs are reflected by elevated concentrations of oxidative stress markers in the breath, airways, lung tissue and blood. The aim of this work was to develop a method for the fast measurement of F2 isoprostanes in exhaled breath condensate (EBC) samples using equipment which is nowadays available and routinely exploited in analytical laboratories, liquid chromatography coupled with tandem mass spectrometry. Because of the limited volume of an EBC sample andthe very low concentrations of biomarkers, we chose lyophilization as the preconcentration technique. The diastereoisomers determined show similar fragmentation patterns, which is why complete chromatographicseparation with excellent peak shapes was essential for accurate quantitation. Isoprostanes were separated using a narrow-bore Agilent Extend C-18 column in isocratic elution mode using acetonitrile/methanol and water with the addition of 0.01%(v/v) formic acid. The limits of determination and quantitation for the determination of four isoprostanes in samples of EBC ranged from 1 to 3 pg/ml. The recoveries of all isoprostanes ranged from 96.7 to 101.7, with a relative standard deviation of <7%. The stability of the isoprostanes at different temperatures was measured as well.
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Separation of CO2 from biogas using absorption columns
- Bartosz Dębski
- Iwona Cichowska-Kopczyńska
Biogaz zawiera ok. 50-70% metanu, 30-40% di tlenku węgla oraz niewielkie ilości innych związków jak siarkowodór czy amoniaku. Dla uzyskania wysokokalorycznego gazu konieczne jest usunięcie ze strumienia di tlenku węgla. Praca opisuje potencjał użycia do tego celu kolumn absorpcyjnych oraz cieczy jonowych jako absorbenta
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Sequence variants of p21 gene of the MRL/MpJ mouse: a possible association with the deficit of p21 protein and regenerative phenotype.
- Bartosz Górnikiewicz
- Paweł Sachadyn
The MRL/MpJ mouse is known for its enhanced regeneration abilities that manifested themselves by scarless ear-hole wound closure. The deficit of p21 found in the MRL is associated with the regenerative capacity as the p21 gene knockout in a mouse strain unrelated to the MRL mouse results in an ear-hole closure effect, similar to that observed in the MRL mouse. Cdkn1a gene encodes p21 protein, a cyclin-dependent kinase inhibitor, which plays an important role in cell cycle regulation. By interacting with CDKs it may stop cell cycle progression at different stages. The p21 gene expression may be initiated from two independent promoters, the classical and the p53-induced one, what is important in case of DNA damage. The cell cycle profile of fibroblast-like cells derived from the MRL mouse shows accumulation in the G2 phase and is different from the profile of the non-regenerative C57BL/6J (B6) mouse. This observation has been explained by the deficit of p21 that causes G1/M cell cycle checkpoint deficiency that results in the uncontrolled entrance into the S phase, which entails the replication stress that involves the endogenous DNA damage. Moreover p21 is not detected in the MRL tissues, even after γ-irradiation, although p53, which up-regulates p21 expression after DNA damage, is constantly present. In our research, we have attempted to investigate the genetic background of p21 deficiency in the MRL mouse. We sequenced the p21 gene of the MRL mouse and compared its nucleotide sequence with 17 already known gene sequences of other laboratory murine strains. We identified a few nucleotide sequence variants that are unique for the MRL mouse in the first intron of the p53-dependent transcript (in/dels) and in the vicinity of the p53-dependent promoter (single nucleotide substitutions). As we found no aberrant splicing variants, we quantified the levels of two p21 transcripts variants in various tissues of the MRL and the control B6 mouse. No dramatic decrease in the p21 transcript levels in the MRL mouse was revealed. The results indicate that the transcriptional regulation of p21 is not responsible for the reported deficit of p21 protein in the MRL mouse. The location of the MRL specific nucleotide sequence variants in the first intron of the p53-dependent p21 transcript and in the vicinity of the p53-dependent promoter may also be associated with the observation that the expression of p21 protein in the MRL mouse is not induced following γ-irradiation.
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Service and Path Discovery Extensions for Self-forming IEEE 802.11s Wireless Mesh Systems
- Krzysztof Gierłowski
With the rapid growth of the quantity and capabilities of end-user electronic devices, both stationary and mobile, they are employed in increasing number of applications. In this situation, wireless network technologies begin to play a crucial role as networks access technologies, as cable-based solutions tend to be of limited utility in case of easily portable or mobile devices. Resulting development of wireless technologies reached a stage, where each connecting client can extend its overall resources by becoming a network node capable of forwarding transit traffic. This ability allows a severe reduction of the necessary operator provided infrastructure, comparedto classic point-to-multipoint systems. It is also a significant step towards ubiquity of network access, as such wireless mesh systems tend to provide through coverage. One of the most promising wireless mesh solutions currently being developed is an IEEE 802.11s standard. However, despite its advantages, a number of areas lack sufficient support, which can lead to significant inefficiency and degradation of service quality in real-world IEEE 802.11s network deployments. In the paper we propose two extensions of IEEE 802.11s mechanisms, designed to provide better service quality in case of real-world deployment scenarios, especially in case of large systems. Both propositions introduce modifications to mesh path discovery and interworking procedures, while retaining compatibility with standard solution. Their basic functionality and efficiency have been verified by means of simulation model in self-organizing infrastructure and access system mesh deployment scenario. The results clearly indicate their utility, particularly in case of larger deployments of this type. The presented solutions are part of an ongoing research concerning cross-layer mechanisms for IEEE 802.11sbased systems, currently reaching testbed implementation stage.
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Sezonowość produkcji wody wodociągowej w aglomeracjach miejskich w latach 1996-2009
- Tadeusz Siuzdak
Problem sezonowości produkcji i sprzedaży wody w systemie wodociągowym. Analiza na przykładzie kilku wybranychy aglomeracji miejsko - przemysłowych. Metodyka, rezultaty