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Wyszukujesz frazę "Piotrowski, W." wg kryterium: Autor


Wyświetlanie 1-6 z 6
Tytuł:
Extension of Usable Spectral Range of Peltier Cooled Photodetectors
Autorzy:
Piotrowski, A.
Piotrowski, J.
Gawron, W.
Pawluczyk, J.
Pedzinska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1807657.pdf
Data publikacji:
2009-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.60.Gz
82.80.Gk
73.61.Ga
78.66.Hf
81.05.Dz
Opis:
This paper provides update on development of the Peltier cooled detectors optimized for wavelengths above 13 μm. Initially, the devices made by Vigo were mostly used for uncooled detection of $CO_{2}$ laser radiation. Over the years the performance and speed of response has been steadily improved. At present the uncooled or Peltier cooled photodetectors can be used for sensitive and fast response detection in the mid-wavelength and long-wavelength infrared spectral range. The devices have found important applications in IR spectrometry, quantum cascade laser based gas analyzers, laser radiation alerters and many other IR systems. Recent efforts were concentrated on the extension of useful spectral range to > 13 μm, as required for its application in Fourier transform IR spectrometers. This was achieved with improved design of the active elements, use of monolithic optical immersion technology, enhanced absorption of radiation, dedicated electronics, series connection of small cells in series, and last but not least, applying more efficient Peltier coolers. Practical devices are based on the complex HgCdTe heterostructures grown on GaAs substrates with metal-organic chemical vapor deposition technique with immersion lens formed by micromachining in the GaAs substrates. The results are very encouraging. The devices cooled with miniature 4 stage Peltier coolers mounted in TO-8 style housings show significant response at wavelength exceeding 16 μm.
Źródło:
Acta Physica Polonica A; 2009, 116, S; S-52-S-55
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie wysokorozdzielczych danych obrazowych w opracowaniach kartograficznych do celów wojskowych
Very High Resolution Imagery Data in Cartographic Elaborations for Military Use
Autorzy:
Bauer, R.W.
Piotrowski, A.
Stępień, G.
Powiązania:
https://bibliotekanauki.pl/articles/204232.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Geograficzne
Tematy:
wysokorozdzielcze dane obrazowe
analizy geoprzestrzenne
baza danych georeferencyjnych
mapa obrazowa
very high resolution imagery data
geospatial analysis
georeferenced database
image map
Opis:
W artykule przedstawiono wykorzystanie wysokorozdzielczych danych obrazowych do celów wojskowych. Autorzy wskazali trzy zasadnicze obszary wykorzystania danych fotogrametrycznych i teledetekcyjnych, którymi są mapy wektorowe (bazy danych georeferencyjnych), analizy geoprzestrzenne oraz opracowania specjalne - mapy obrazowe (image maps). Przedstawiono zalety i ograniczenia ortofotomapy satelitarnej i innych opracowań specjalnych, wykonywanych i wykorzystywanych przez wojska NATO w warunkach pokoju oraz w strefie działań wojennych.
The article presents the application of very high resolution imagery data in military cartographic elaborations. Three basic areas of application photogrammetry and remote sensing data have been indicated: vector maps (georeferenced data bases), geospatial analysis and special elaborations - image maps. Basic vector data bases created by NATO using very high resolution imagery data are mainly Vmap bases (vector map bases) with detail levels corresponding to information resolution of particular scales of cartographic elaboration: LO -1:1 000 000, L1 - 1:250 000, L2 - 1:50 000 and L3 - 1:25 000. Military vector maps (Vmap) enable spatial analyses using topology of presented terrain objects and attributes assigned to them. The other data base elaborated as part of an international agreement (including Poland) which uses very high resolution satellite images is the basis created within the framework of the MGCP project (Multinational Geospatial Co-production Program), in which 32 countries currently participate. MGCP is a global basis. The idea of the project is to create data for regions of interest, areas of current and potential conflicts and threats. The characteristic feature of data in the MGCP project is the fact that they don't include a full range of objects required to create some kinds of maps, e.g. the topographic map. These data cannot be field verified and horizontal detail of object location should have an error of no more than 25 meters. Information concerning borders, their course and status can be treated differently in each country taking part in the program, so in order to avoid potential conflict of interest it has been decided not to include such data in MGCP. The article also presents special elaborations done during stability missions in Iraq and Afghanistan. Image maps have presently become basic cartographic material in regions of conflict and hazards. They also constitute the basis for conducting further analyses. They are special maps (which thus do not undergo strict standard limitations), so the information range, scale and sheet size are conformed to particular user needs and the task performed. Application of very high resolution area imageries on stability missions in war zones is common practice. This is done because of the particularities of climatic, meteorological, logistical and organizational conditions as well as safety precautions. The article characterizes kinds of image data used by the army while showing the possibilities of creating cartographic elaborations and conducting geospatial analyses on the basis of this data. Through current image data it is possible to create quick cartographic elaborations mainly used in war zones, but which are more and more often made useful in elaborations intended for use during times of peace. Usage of satellite images has led to the emergence of a new type of product - image maps. Their elaboration standards have a loosely defined reference system and content range. Their applications are limited, e.g. they cannot be used for precise navigation. The kind of realized task and map addressee requirements are decisive here.
Źródło:
Polski Przegląd Kartograficzny; 2013, T. 45, nr 1, 1; 25-35
0324-8321
Pojawia się w:
Polski Przegląd Kartograficzny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fast Response Hot (111) HGCDTE MWIR Detectors
Autorzy:
Grodecki, K.
Martyniuk, P.
Kopytko, M.
Kowalewski, A.
Stępień, D.
Kębłowski, A.
Piotrowski, A.
Piotrowski, J.
Gawron, W.
Rogalski, A.
Powiązania:
https://bibliotekanauki.pl/articles/221254.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
HgCdTe
MWIR
photodetector
response time
Opis:
In this work we report simulation and experimental results for an MWIR HgCdTe photodetector designed by computer simulation and fabricated in a joint laboratory run by VIGO Sytems S.A. and Military University of Technology. The device is based on a modified N+pP+ heterostructure grown on 2”., epiready, semi-insulating (100) GaAs substrates in a horizontal MOCVD AIX 200 reactor. The devices were examined by measurements of spectral and time responses as a function of a bias voltage and operating temperatures. The time response was measured with an Optical Parametric Oscillator (OPO) as the source of ~25 ps pulses of infrared radiation, tuneable in a 1.55–16 μm spectral range. Two-stage Peltier cooled devices (230 K) with a 4.1 μm cut-off wavelength were characterized by 1.6 × 1012 cm Hz1/2/W peak detectivity and < 1 ns time constant for V > 500 mV.
Źródło:
Metrology and Measurement Systems; 2017, 24, 3; 509-514
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of TDMAAs Acceptor Precursor on Performance Improvement of HgCdTe Photodiodes
Autorzy:
Madejczyk, P.
Gawron, W.
Piotrowski, A.
Kłos, K.
Rutkowski, J.
Rogalski, A.
Powiązania:
https://bibliotekanauki.pl/articles/1506804.pdf
Data publikacji:
2010-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.79.Pw
07.57.Kp
73.21.Cd
78.67.Pt
79.60.Jv
Opis:
One of the key factor which determine HgCdTe photodiode quality is acceptor doping efficiency. This paper presents significant progress made over the past three years in development of acceptor doping technology in metalorganic chemical vapour deposition HgCdTe photovoltaic detectors. High acceptor doping is required for $P^{+}$-contact layers, whereas low doping is necessary for p-type absorbing base layer. Previously, $AsH_3$ precursor was used as an acceptor dopant. This precursor is partially incorporated as electrically neutral As-H pairs, which are likely to be recombination centres in HgCdTe and in consequence influence on the carriers lifetime lowering. Substituting of $AsH_3$ by TDMAAs resulted in higher carrier lifetimes and thereby about one order of magnitude higher $R_0A$ product of HgCdTe photodiodes in temperatures close to 230 K.
Źródło:
Acta Physica Polonica A; 2010, 118, 6; 1199-1204
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sedimentary evidence of extreme storm surge or tsunami events in the southern Baltic Sea (Rogowo area, NW Poland)
Autorzy:
Piotrowski, A.
Szczuciński, W.
Sydor, P.
Kotrys, B.
Rzodkiewicz, M.
Krzymińska, J.
Powiązania:
https://bibliotekanauki.pl/articles/2060594.pdf
Data publikacji:
2017
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
tsunami deposits
storm surge deposits
grain size analysis
geochemistry
radiocarbon dating
Baltic Sea
Opis:
The Baltic Sea is not typically considered as an area affected by tsunamis. However, during the Late Pleistocene and Holocene several tsunami events have been interpreted from the sedimentary record, mainly in Sweden and Estonia. Furthermore, on the southern coast of the Baltic Sea, there are historical accounts of catastrophical marine floodings called “der Seebär” (“the Sea Bear”). Their descriptions reveal many features typical for tsunami, but their genesis remained unknown and sedimentary evidence for such events has not been found. Here we provide evidence of sandy event layers from the area of Rogowo, NW Poland – the area of historical catastrophic storms as well as “der Seebär” events. The study area is a low-lying coastal plain with an average elevation of –0.5 to +0.5 m a.s.l., protected from the open sea by beach and coastal dune systems up to 5 m high. Sedimentological, micropalaeontological and geochemical analyses along with AMS 14C dating were applied to sedimentary successions seen in 5 major trenches and 198 sediment cores up to 1.5 m long. Two sandy layers were identified in the peat deposits that developed on the plain during the last ~2000 years. They reveal a number of typical features of tsunami deposits (significant lateral extent and thickness, rip-up clasts, chemical and micropalaeontological evidence of marine origin), however, 14C dating along with the historical accounts revealed that the major layer, extending at least 1.2 km from the modern coasts, was probably deposited by arguably the largest storm surge during the last 2000 years, which took place in 1497 AD. These storm deposits were likely formed during inundation of the low-lying coastal plain after major breaching of coastal dunes resulting in tsunami – like flow pattern and thus similar sedimentological effects. A discontinuous sand layer of younger age (18th century) and sharing similar properties to the previous one may be related to “der Seebär” event or another storm surge. The study revealed that the southern Baltic Sea coast may be affected by much greater coastal flooding than known from more recent accounts and observations. Thus, the presented geological record should be taken as an example of a worst-case scenario in coastal zone risk assessment from natural hazards. These events left sedimentary deposits that resemble tsunami deposits. It is likely that, in similar settings where storm surges cause unidirectional inundation of a coastal plain, it may not be possible to establish whether the resulting deposits were laid down from storms or tsunamis.
Źródło:
Geological Quarterly; 2017, 61, 4; 973--986
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of an ATCA-based LLRF system at FLASH
Autorzy:
Simrock, S.
Butkowski, Ł.
Grecki, M.
Jeżyński, T.
Koprek, W.
Jabłoński, G.
Jałmużna, W.
Makowski, D.
Piotrowski, A.
Sakowicz, B.
Czuba, K.
Powiązania:
https://bibliotekanauki.pl/articles/397843.pdf
Data publikacji:
2010
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
akcelerator
sterowanie
sprzężenie zwrotne
accelerator
control
feedback
Advanced TCA
Opis:
Future RF Control systems will require simultaneous data acquisition of up to 100 fast ADC channels at sampling rates of around 100 MHz and real time signal processing within a few hundred nanoseconds. At the same time the standardization of Low-Level RF systems are common objectives for all laboratories for cost reduction, performance optimization and machine reliability. Also desirable are modularity and scalability of the design as well as compatibility with accelerator instrumentation needs including the control system. All these requirements can be fulfilled with the new telecommunication standard ATCA when adopted to the domain of instrumentation. We describe the architecture and design of an ATCA based LLRF system for the European XFEL. Initial results of the demonstration of such a system at the FLASH user facility will be presented. Presented are the results of operating essential components of a prototype during the machine studies in January and March 2009.
Źródło:
International Journal of Microelectronics and Computer Science; 2010, 1, 1; 48-51
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

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