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Number of results: 91
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Abstract

Diagenetic carbonate deposits (concretions, cementation bodies and cementstone bands) commonly occur in organic carbon-rich sequence of the Agardhfjellet Formation (Upper Jurassic) in Spitsbergen . They are dominated by dolomite/ankerite and siderite. These deposits originated as a result of displacive cementation of host sediment in a range of post-depositional environments, from shallow subsurface to deep-burial ones. Preliminary results of the carbon and oxygen isotopic survey of these deposits in southern Spitsbergen (Lĺgkollane, Ingebrigtsenbukta, Reinodden, and Lidfjellet sections) show the δ13C values ranging between –13.0‰ and –1.8‰ VPDB, and the δ18O values between –16.0‰ and –7.7‰ VPDB. These results suggest that the major stage of formation of the carbonate deposits occurred during burial diagenesis under increased temperature, most probably in late diagenetic to early catagenic environments. Carbonate carbon for mineral precipitation was derived from dissolution of skeletal carbonate and from thermal decomposition of organic matter.

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Krzysztof P. Krajewski
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Abstract

The area of NW Wedel Jarlsberg Land south of Bellsund (Spitsbergen), between Dunderbukta in the west and the Berzeliustinden mountain group in the east, consists of five fault-bounded blocks: (1) the Renardbreen Block (Middle–Late Proterozoic basement rocks), (2) the Chamberlindalen Block (Late Proterozoic basement rocks), (3) the Martinfjella Block (Late Proterozoic through Early Ordovician basement rocks), (4) the Berzeliustinden Block (Late Proterozoic and Early Ordovician basement rocks covered by Late Palaeozoic–Tertiary platform deposits), (5) the Reinodden Block (Late Palaeozoic and Mesozoic rocks). The paper presents an outline of lithostratigraphy (Middle/Upper Proterozoic–Lower Ordovician: Hecla Hoek Succession) and architecture of the Caledonian basement in which several thrust-sheets and thrust-folds have been recognized. It also discusses some aspects of Tertiary overthrusting, faulting and rotation with affected the basement rocks and remodelled its Caledonian architecture.

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Krzysztof Birkenmajer
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Abstract

Ninety eight polychaete species were found in the shallow sublittoral of Admiralty Bay. The most abundant were Leitoscoloplos kerguelensis, Tauberia gracilis, Ophelina syringopyge, Rhodine intermedia, Tharyx cincinnatus, Aricidea (Acesta) strelzovi, Apistobranchus sp., Cirrophorus brevicirratus and Microspio moorei. Mean abundance of polychaetes was estimated at 120 ind./ 0.1m2. As a result of cluster analysis several polychaete assemblages were distinguished. The highly specific assemblage with two characteristic species, Scoloplos marginatus and Travisia kerguelensis, from shallow areas with sandy bottom situated far from glaciers; a distincly specific assemblage with Apistobranchus sp. from poorly sorted sediments in the bottom areas situated on the slopes at the base of steep rubble shores; the richest and most diverse, highly specific polychaete assemblage from the central basin of the bay with Tauberia gracilis as the most characteristic species, as well as two assemblages from the bottom areas neighbouring glaciers and influenced by the intensive enrichment of very small grain-sized sediments with Ophelina cylindricaudata and Tharyx cincinnatus. Clear assemblages’ arrangement was observed along the gradient: sand, silty sand, silt towards clay silt. Other important factors, supporting the proposed classification of assemblages and their character, include the sorting coefficient of the sediment (So) as well as the slope of the bottom. The between-habitat diversity of polychaete fauna is strongly connected with the phenomena occurring in the neighbouring terrestrial coastal areas.

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Jacek Siciński
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Abstract

The occurrence of coreless winters in the South Shetland Islands region is related to increase in the intensity of cyclonic circulation and to the presence of massive and rapid advection of warm air northerly and westerly. Coreless winter developments depend on large-scale oceanic processes – the presence of positive anomalies in sea surface temperature (SST) in the Bellingshausen Sea over the range 080°–092°W and the retreat of sea ice extent southwards. When negative anomalies of SST in the same region are observed and the sea ice extent advances northwards, a winter with clearly marked cold core is experienced at the Arctowski Station on the South Shetlands.

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Authors and Affiliations

Anna Styszyńska
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Abstract

The new rich collection of fossil fish remains obtained during the Polish Spitsbergen Expedition of 1998 includes many isolated shark teeth, mostly of the genera Lissodus, Hybodus and Acrodus. The shark microfossils from the Hornsund area (South Spitsbergen) described here and the analysis of the histology of Lissodus teeth contribute to a better understanding of the previously described Early Triassic fish fauna from that region (Birkenmajer and Jerzmańska 1979). There is the evidence for coexistence of two types of histology within a single taxon what closes the discussion considering ortho- and osteodentine as a taxonomic factor.

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Błażej Błażejowski
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Abstract

Nematodes occurring in the Antarctic bony fishes are reviewed, and keys based on morphological features are presented. Five valid species: Ascarophis nototheniae Johnston et Mawson, 1945; Cystidicola beatriceinsleyae (Holloway et Klewer, 1969); Dichelyne fraseri (Baylis, 1929); Hysterothylacium aduncum (Rudolphi, 1802); Paranisakiopsis weddelliensis Rocka, 2002, and one unnamed form, Capillaria (Procapillaria) sp., have been reported from the Antarctic teleosts. Also, larval anisakids, in the adult stage parasites of marine mammals, birds and fishes, occur commonly in the Antarctic and Subantarctic bony fishes. They belong to Contracaecum spp., Anisakis spp., Pseudoterranova decipiens (Krabbe, 1878) and Hysterothylacium aduncum.

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Anna Rocka
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Abstract

A sequence of glacial deposits up to 4 m thick unconformably overlies the Eocene La Meseta Formation on the Seymour Island plateau (meseta) and forms a lithostratigraphically distinct unit in the succession of the James Ross Basin, which is formally named here as the Weddell Sea Formation. The formation is thus far known only from Seymour Island. This is a terrestrial melt-out till which contains abundant erratics and also reworked Cretaceous–Tertiary micro- and macrofossils within a silty clay matrix. The terrestrial origin of this till is shown by glacial striations at the base of the unit. The largest erratics (up to 3 m in diameter) are composed of plutonic (granitoids) and metamorphic (gneiss and crystalline schist) rocks of the Antarctic Peninsula provenance. Smaller in size and much more numerous are erratics of volcanic rocks, represented by andesite, basalt and corresponding pyroclastics of the James Ross Island Volcanic Group. Less common are erratics of sedimentary rocks, sometimes bearing fossils derived from the underlying Tertiary and Cretaceous strata. A few erratics from the top of the studied sequence are conglomerates of the Cockburn Island Formation with a foraminifer fauna. These are the youngest clasts within the Weddell Sea Formation. The presence of the Pliocene index fossil Ammoelphidiella antarctica Conato et Segre, 1974 indicates a lower age limit of latest Pliocene or earliest Pleistocene age. The upper age limit of the formation has not been established. An encrusting, unilamellar, colony of the bryozoan Escharella Gray, 1848 has been found on the one of erratics from the Weddell Sea Formation. This is the first fossil record of this genus in Antarctica.

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Authors and Affiliations

Andrzej Gaździcki
Andrzej Tatur
Urszula Hara
Rodolfo A. del Valle
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Abstract

Palaeomagnetic investigation of the Upper Carboniferous clastic Hyrnefjellet Formation from opposite limbs of the Hyrnefjellet Anticline in southern Spitsbergen (Svalbard Archipelago) uncovered two components of NRM. Direction C1 (D = 224.6°; I = –27.9°; κ = 22.40; α95% = 5.6°) is of prefolding origin and most probably of near-primary origin. High Tb spectra above 575°C indicate hematite as the carrier of C1. Acquisition of the C1 component may be related to an early diagenetic crystallization of hematite, not excluding a detrital origin of the NRM. A paleopole calculated for the C1 component (F = 23.3°N; L= 147.7°E) falls into the Late Devonian–Early Carboniferous sector of APWP for Baltica. This result suggests that Svalbard remained in the present day orientation with respect to Baltica since the Carboniferous time. A second component with intermediate unblocking temperatures, determined in the Hyrnefjellet Formation deposits, is labelled C2. Its mean orientation for in situ position is D = 11.2°; I = 69.2° (κ = 44.05; α95% = 6.3°), thus being similar to Late Mesozoic directions for Baltica. After 100% tectonic correction for tilting of anticline limbs and axis, the C2 component orientation is D = 265.7°; I = 59.7°, thus being distant from any directions for Baltica. Detailed analysis suggest that the C2 component is most probably of synfolding origin, and it was formed during the Tertiary Alpine Tectonic Event.

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Authors and Affiliations

Krzysztof Michalski
Marek Lewandowski
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Abstract

Schistidium cupulare (Müll. Hal.) Ochyra, an obscure and poorly known species originally described from Îles Kerguelen as Grimmia cupularis Müll. Hal. and subsequently reported from a single station in the Antarctic, is re-assessed taxonomically. It is considered to be a distinct species of sect. Conferta, closely related to S. amblyophyllum (Müll. Hal.) Ochyra et Hertel, from which it differs in its distal- and mid-leaf areolation of short, isodiametric, quadrate to shortly rectangular cells; stouter costa, 50–75 μm wide in the distal and median part, semi-terete to subrectangular in cross-section and prominently convex on the dorsal surface, (2–)3-stratose above, 3(–4)-stratose below; leaf margins regularly 2–3-stratose in 1–3 rows of cells forming fleshy, bulging limbidia; presence of a distinct central strand; and finely roughened to nearly smooth peristome teeth. S. celatum (Cardot) B.G. Bell from South Georgia and Tierra del Fuego is considered to be conspecific with S. cupulare. Some details of the type specimens of both species are illustrated. The geographical range of S. cupulare is evaluated and it is considered to be an amphiatlantic subantarctic species. A new record of the species from Livingston Island in the Antarctic is provided and a key to species of Schistidium in Antarctica is given.

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Authors and Affiliations

Ryszard Ochyra
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Abstract

On the basis of the distinctly biplicate and carinate leaves in the distal portion Grimmia lawiana J.H. Willis, the only continental Antarctic endemic moss species, is transferred to the genus Coscinodon Spreng. and the new combination C. lawianus (J.H. Willis) Ochyra is proposed. The species is described and illustrated, its affinities are discussed and its geographical distribution in the Antarctic is mapped. Grimmia reflexidens Müll. Hal., a southern South American endemic species from Chile , is briefly assessed and this species is also shifted to Coscinodon as C. reflexidens (Müll. Hal.) Ochyra, comb. nov. A key to all species of the genus Coscinodon is presented. Guembelia longirostris (Hook.) Ochyra et Żarnowiec is reported for the first time from the Antarctic on the basis of a specimen collected from the Nordenskjöld Coast on the eastern coast of the Antarctic Peninsula.

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Authors and Affiliations

Ryszard Ochyra
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Abstract

Zooplankton community composition, abundance and biomass from two polar localities – Kongsfjorden (Arctic) and Admiralty Bay (Antarctic) is compared. The community composition of zooplankton in both polar regions included similar taxonomic groups and the diversity at the species level was similar. Even though the overall species composition was different, some species were common for both ecosystems, for example Oithona similis, Microcalanus pygmaeus or Eukrohnia hamata. The abundance and biomass of the main zooplankton components (Copepoda) differed greatly between the two ecosystems, both being of an order of magnitude higher in Kongsfjorden than in Admiralty Bay. Kongsfjorden is situated at the border of two regions what induces high productivity with copepods playing an important role, and there is also a strong advection into the fjord. Admiralty Bay is adjacent to the homogenous Antarctic oceanic ecosystem; some advection into the bay occurs as an effect of tide and wind driven processes. Antarctic krill, which was not included in the present study, occupies most of the primary consumers niche and replaces copepods at the second trophic level.

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Authors and Affiliations

Wojciech Walkusz
Sławomir Kwaśniewski
Katarzyna Dmoch
Haakon Hop
Maria Iwona Żmijewska
Luiza Bielecka
Stig Falk-Petersen
Jacek Siciński
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Abstract

Ground temperature variations have been analysed to the depth of 160 cm, with respect to meteorological elements and short-wave radiation balance. The database of the ground temperature covers a thirteen month-long period (May 1992 – June 1993), which included both the seasons of complete freezing of the ground and thaw. Special attention has been given to the development of perennial permafrost and its spatial distribution. In summer, the depth of thawing ground varied in different types of ground — at the Polish Polar Station, this was ca. 130 cm. The ground froze completely in the first week of October. Its thawing started in June. The snow cover restrained heat penetration in the ground, which hindered the ground thawing process. Cross-correlation shows a significant influence of the radiation balance (K*) on the values of near-surface ground temperatures (r2 = 0.62 for summer).

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Authors and Affiliations

Jan Leszkiewicz
Zbigniew Caputa
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Abstract

Deep seismic sounding measurements were performed in the continent-ocean transition zone of north-western Spitsbergen , during the expedition ARKTIS XV/2 of the RV Polarstern and the Polish ship Eltanin in 1999. Profile AWI-99200 is 430 km long and runs from the Molloy Deep in the Northern Atlantic to Nordaustlandet in north-eastern Svalbard . Profile AWI-99400 is 360 km long and runs from the Hovgĺrd Ridge to Billefjorden. Seismic energy (airgun and TNT shots) was recorded by land (onshore) seismic stations (REF) and ocean bottom seismometers (OBS) and hydrophone systems (OBH). Good quality refracted and reflected P waves were recorded along the two profiles providing an excellent data base for a detailed seismic modelling along the profile tracks. Clear seismic records from airgun shots were obtained up to distances of 200 km at land stations and 50 km at OBSs. TNT explosions were recorded even up to distances of 300 km . A minimum depth of about 6 km of the Moho discontinuity was found east of the Molloy Deep. Here, the upper mantle exhibits P-wave velocity of about 7.9 km/s, and the crustal thickness does not exceed 4 km . The continent–ocean transition zone to the east is characterised by a complex seismic structure. The zone is covered by deep sedimentary basins. The Moho interface dips down to 28 km beneath the continental part of the 99200 profile, and down to 32 km beneath the 99400 profile. The P-wave velocity below the Moho increases up to 8.15 km/s. The continental crust consists of two or three crystalline layers. There is a lowermost crustal continental layer, in the 99400 profile’s model, with the P-wave velocity in order of 7 km/s, which does not exist in the continental crust along the 99200 profile. Additionally, along the 99200 profile, we have found two reflectors in the lower lithosphere at depths of 14–42 and 40–50 km dipping eastward, with P-wave velocity contrasts of about 0.2 km/s. The characteristics of the region bears a shear-rift tectonic setting. The continent–ocean transition zone along the 99200 profile is mostly dominated by extension, so the last stage of the development of the margin can be classified as rifting. The uplifted Moho boundary close to the Molloy Deep can be interpreted as a south-western end of the Molloy Ridge. The margin in the 99400 profile area is of transform character.

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Authors and Affiliations

Wojciech Czuba
Oliver Ritzmann
Yuichi Nishimura
Marek Grad
Rolf Mjelde
Aleksander Guterch
Wilfried Jokat
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Abstract

The cephalopod diet of the gentoo penguin, Pygoscelis papua and the Antarctic fur seal, Arctocephalus gazella was comparatively analyzed at Laurie Island, South Orkney Islands. A total of 125 stomach samples were collected by the water off-loading method from gentoo penguins during the autumns of 1993, 1995 and 1996, and 39 fur seal scats were collected from mid March to April 1988. Cephalopods preyed upon by gentoo penguins were represented by 1974 beaks (1628 lower, 346 upper) which occurred in 50.4% of the samples. Lower beaks identified belonged exclusively to the squid Psychroteuthis glacialis. The mean lower rostral length (LRL) of these beaks was 1.1 mm (range 0.4– 1.8 mm). From the Antarctic fur seal scats 103 beaks (41 lower, 62 upper) were removed from 60.6% of scats which contained prey remains. The cephalopod species identified were Slosarczykovia circumantarctica and P. glacialis which constituted 78.8% and 21.1% in terms of numbers, respectively. The mean lower rostral length for S. circumantarctica was 2.7 mm (range 2.0–3.5 mm), while that of P. glacialis was 1.6 mm (range 1.0–2.5 mm). The foraging behaviour of the two top predators was analyzed and discussed according to the composition and size of their cephalopod prey.

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Authors and Affiliations

Marcela M. Libertelli
Gustavo A. Daneri
Uwe Piatkowski
Nestor R. Coria
Alejandro R. Carlini
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Abstract

This publication begins series of papers on taxonomy of juvenile and little known Mesozoic gastropods from Siberia and Timan region (= Pechora Basin). First part contains general part with geological framework followed by the paleontological part on taxonomy of Vetigastropoda and Caenogastropoda (exclusive of Neogastropoda). Described are 15 species of gastropods. Three of them are new. They are Chuelskia siberica (Trochidae), Ageria gankinensis (Epitoniidae), and Dzikella chuzikovensis (superfamily and family uncertain). Moreover, described is a new genus Chuelskia (Trochidae). Eight species are left in the open nomenclature. The Siberian gastropods belong mostly to the cosmopolitan fauna while the gastropods of Timan region are the same as those already described from Novaja Zemlja Islands.

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Authors and Affiliations

Andrzej Kaim
Alexander L. Beisel
Nikolai I. Kurushin
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Abstract

The fundamental concepts of nano and quantum systems of informatics have been presented. The nanotechnological processes taking place in biological systems of informatics have been discussed in terms of informatics. Presented analysis shows that the application of nanotechnologies in the technical informatic systems enables realization of processes for formation of products and objects with self-replication feature, similarly to the processes existing in biological informatic systems. It seems also that the quantum technologies enable further miniaturization of the technical systems of informatics as well as make the execution time of some computing processes like, e.g. Shor's and Grover's algorithms, shorter.

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Authors and Affiliations

S. Węgrzyn
J. Klamka
L. Znamirowski
R. Winiarczyk
S. Nowak
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Abstract

The self-consistent optical-electrical-thermal-gain model of the oxide-confined edge-emitting diode laser has been used to simulate the room-temperature operation of the long-wavelength 1.3-µm quantum-dot (InGa)As/GaAs diode laser. The validityof the model has been verified using some experimental results for comparison. An impact of quantum-dot densityon laser operation characteristics as well as on temperature dependence of lasing threshold have been discussed.

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Authors and Affiliations

R.P. Sarzała
M. Wasiak
T. Czyszanowski
W. Nakwaski
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Abstract

Conceptions of analogue electronics circuit based on a multiple-input floating gate field-effect transistor MOS (MIFGMOS) have

been presented. The simple add and differential voltage amplifiers with one and two MIFGMOS transistors and multiple-input operational amplifiers with their application have been proposed. One of them was used for the realisation of a controlled floating resistor. Results of circuit simulations in SPICE programme using the simple substitute macromodel of MIFGMOS transistor have been shown.

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Authors and Affiliations

L. Topór-Kamiński
P. Holajn
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Abstract

Biocompatible coatings produced on the basis of the chemically extracted natural hydroxyapatite (HAp) from the animal bones were deposited using multiplex method comprising glow discharge nitriding (GDN) of the titanium alloy substrate and pulsed laser deposition (PLD) of HAp on the formerly fabricated titanium nitride layer (TiN). The TiN interlayer plays an important role improving adhesion of HAp to substrate and preserves the direct contact of the tissue with metallic substrate in the case of possible cracking of HAp coating. Surface morphology of deposited layers, crystallographic texture and residual stress were studied in relation to the type of laser applied to ablation (Nd:YAG or ArF excimer), laser repetition, temperature of substrate and atmosphere in the reactive chamber.

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Authors and Affiliations

B. Major
T. Wierzchoń
W. Mróz
K. Haberko
R. Ebner
J. Bonarski
R. Major
A. Prokopiuk
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Abstract

A short overview of the developments of functional materials featuring miniaturisation and integration is illustrated by examples taken from the ?eld of ceramic functional materials. To obtain new materials new methods are required. Most of them are microfabrication processes developed by the "top-down" approach.

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R. Pampuch
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Abstract

Resonance assignment remains one of the hardest stages in RNA tertiary structure determination with the use of Nuclear Magnetic Resonance spectroscopy. We propose an evolutionary algorithm being a tool for an automatization of the procedure. NOE pathway, which determines the assignments, is constructed during an analysis of possible connections between resonances within aromatic and anomeric region of 2D-NOESY spectra resulting from appropriate NMR experiments. Computational tests demonstrate the performance of the evolutionary algorithm as compared with the exact branch-and-cut procedure applied for the experimental and simulated spectral data for RNA molecules.

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Authors and Affiliations

J. Błażewicz
M. Szachniuk
A. Wojtowicz
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Abstract

The issue of maximizing penetration depth with concurrent retaining or enhancement of image resolution constitutes one of the time invariant challenges in ultrasound imaging. Concerns about potential and undesirable side effects set limits on the possibility of overcoming the frequency dependent attenuation effects by increasing peak acoustic amplitudes of the waves probing the tissue. To overcome this limitation a pulse compression technique employing 16 bits Complementary Golay Sequences (CGS) Code was implemented at 4 MHz. In comparison with other, earlier proposed, coded excitation schemes, such as chirp, pseudo-random chirp and Barker codes, the CGS allowed virtually side lobe free operation. Experimental data indicate that the quality — resolution, signal penetration and contrast dynamics — of CGS images is better than the one obtain for standard ultrasonography using short burst excitation.

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Authors and Affiliations

A. Nowicki
W. Secomski
I. Trots
J. Litniewski

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