Wyniki wyszukiwania - Biblioteka Nauki

1

Lasery i nowe techniki w konserwacji zabytków międzynarodowe programy badawcze

100%

Śliwiński G.

Zeszyty Naukowe Instytutu Maszyn Przepływowych Polskiej Akademii Nauk w Gdańsku

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2002

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tom nr 524/1483

47--60

EN

The problem of novel, radiation techniques in artwork conservation, analysis and diagnostics is considered on the basis of thematically associated, European and pan-European R&D programs. It is shown, that since several years numerous projects covering a broad range of research topics which are of common interest for conservators and scientists have been successfully realized and also next ones have been initiated recently. Examples of programs such as the V FP, Eureka, COST and selected thematic actions are given and advantages due to participation of polish interdisciplinary groups are discussed. The conclusion on the role of radiation techniques in the conservator's practice indicates that these techniques should be considered as complementary ones rather than competitive.

2

Analiza parametrów oceny płynnego poziomu bezpieczeństwa sieci korporacyjnej

63%

Korostil J. , Śliwiński G.

Studia Informatica

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2003

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tom Vol. 24, nr 2B

117-124

PL

Każda sieć korporacyjna posiada pewne informacje, które powinny być chronione. Jednak poziom zabezpieczeń w obecnym czasie określany jest w sposób statyczny, czyli przy budowie systemu określa się pewne parametry krytyczne systemu i na ich podstawie buduje się system bezpieczeństwa o ściśle określonym, nigdy niezmiennym poziomie. Często też prowadzi się do weryfikacji zabezpieczeń (brak sprzężenia zwrotnego w systemie bezpieczeństwa), co powoduje, że informacje tam zgromadzone są zabezpieczone niedostatecznie

EN

Every corporate network has some information that should be protected. However, nowadays security level is specified in the static mode, so some critical system parameters are specified while the system is built and based on that information the security system is created on the exactly specified and unchangeable level. Often, the verification of securities are not realised (there is no feedback in the security system) and that causes the information stored there are not sufficiently secured.

3

Określenie bieżącej wartości poziomu bezpieczeństwa sieci korporacyjnej

63%

Śliwiński G. , Korostil J.

Studia Informatica

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2002

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tom Vol. 23, nr 2B

271-277

PL

W obecnym czasie występuje dość dużo różnych sposobów ochrony sieci korporacyjnej przed groźbą niepowołanej ingerencji w pracę w sieci. Przykładami takich sposobów mogą być: trasery sieciowe systemu stwierdzające atak, środki przeciwdziałające atakom, inne specjalne środki ochrony protokołów łączności. Środki te są ukierunkowane na wykonywanie odrębnych zadań w systemie bezpieczeństwa określonych sieci. Ich koszty są dość wysokie i dlatego nie każdy użytkownik sieci korporacyjnej może sobie pozwolić na ich nabycie i eksploatację.

EN

Nowadays, there is a lot of different ways to secure corporate networks from some attacks. Good examples of such solutions can be network tracerouters, network attacks detection systems and preventives against such attacts and other specialpreventives of connections protocols. These elements are oriented for separated works in security system dedicated networks and because they are very expansive, not everyone can buy ad use such a solution.

4

Laserowe oczyszczanie kamienia w konserwacji obiektów zabytkowych – zastosowanie, aspekty praktyczne oraz ekonomiczne

63%

Jankowska M. , Śliwiński G.

Zeszyty Naukowe Instytutu Maszyn Przepływowych Polskiej Akademii Nauk w Gdańsku

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2002

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tom nr 524/1483

71--86

EN

Laser cleaning used for renovation of historical monuments is considered from the point of view of application capabilities and features important for conservators. For the Nd:YAG laser which is most commonly used in restoration studies the main characteristics indicate that a variety of materials can be efficiently surface-cleaned. The cleaning process can be precisely controlled by means of additional diagnostic techniques. In order to estimate the economic factors of laser application the expenses due to investment, exploitation and also labour costs are discussed and compared with their counterparts characteristic for conventional restoration techniques.

5

Multilayer laser cladding of bronze powder for fast prototyping.

63%

Jendrzejewski R. , Śliwiński G.

Inżynieria Materiałowa

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1998

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tom R. XIX, nr 4

1100-1103

EN

Process parameters of the multilayer laser cladding of the bronze B10 alloy powder are experimentally investigated. The 3-D structures are prepared trace-on-trace by remelting of the powder injected into the processing zone through a nozzle. An efficient formation of the volumetric structures of controlled geometry is observed. Microanalysis of the samples confirm the expected mechanical properties, low porosity and the highly homogeneous structure of the multilayers. For the subsequent clads of 1 mm width and 0,6 mm in height produced at velocities of 1m/min. the process efficiency of about 5% is obtained.

6

Laserowe oczyszczanie piaskowca gotlandzkiego z monitoringiem LIPS

63%

Jankowska M. , Śliwiński G.

Analityka : nauka i praktyka

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2006

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tom nr 2

22-25

PL

Spektroskopia plazmy indukowanej wiązką laserową (LIPS) jest techniką analityczną użyteczną zarówno w analizie, jak i w konserwacji.

7

Doświadczalne badania szybkości usuwania zanieczyszczeń z powierzchni piakowca przy użyciu lasera

63%

Jankowska M. , Śliwiński G.

Zeszyty Naukowe Instytutu Maszyn Przepływowych Polskiej Akademii Nauk w Gdańsku

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2002

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tom nr 522/1481

1-19

EN

The laser ablation process applied for restoration of the stone historical objects is reported and results of the experimental study on laser cleaning of the sandstone samples using the Nd:YAG laser (1064 nm; 6 ns FWHM;fluence 0,I-3 J/cm2) are discussed. Values of the ablation thresholdfor the dry andwet surface cleaning of the black crust of 0.4 J/cm2 and 0.1 J/cm2 are obtained, respectively. For the acoustically monitored ablation process a close correlation between the recorded sound amplitude and the removed layer thiclmess and also exponential decrease of the signal with the irradiation dose are observed. From analysis of the experimental data the optimal processing parameters, i.e. irradiation at 1064 nm andfluence of 0,45 J/cm2 for moistened surface are derived.

8

Stereolitografia laserowa z wykorzystaniem proszków metali: mikrostruktura brązu B10

51%

Jendrzejewski R. , Śliwiński G. , Serbiński W.

Krzepnięcie Metali i Stopów

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1998

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tom nr 36

267--273

PL

W pracy przedstawiono wyniki badań metalograficznych próbek wielowarstwowych wykonanych z przetopionego proszku brązu B10. Do przetapiania warstw proszku użyto lasera CO2 MLT 1200. Do badań napawania zastosowano głowicę roboczą lasera z dwustrumieniową dyszą zapewniającą dostarczanie proszku metalu współosiowo z kierunkiem propagacji wiązki lasera. Mikrostruktura warstw wykonanych dwiema metodami stereolitografii laserowej została porównana z mikrostrukturą brązu B10 odlanego w sposób konwencjonalny.

9

Biblia Leopolity - konserwacja z użyciem lasera oraz badania papieru i wybranych zanieczyszczeń

51%

Kamińska A. , Bredal-Jørgensen J. , Ochocińska K. , Śliwiński G.

Zeszyty Naukowe Instytutu Maszyn Przepływowych Polskiej Akademii Nauk w Gdańsku

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2002

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tom nr 524/1483

157--171

EN

Parts of the Polish oldest, illustrated Leopolita's Bible from XVI cent, are cleaned by the 532 nm Nd:YAG laser pulses and the results are analyzed by means of optical and scanning microscopy. Under mild irradiation conditions, i.e. for beam energy density from the range of 0.3-0.6 J/cm2, and pulse number not exceeding 15, the laser cleaning leads to positive results at locations where previously applied chemical treatment did not. This is confirmed by the microscopic observation and also by comparison of the respective fluorescence spectra obtained under laser excitation at 266 nm. It is shown, that for the case of laser application for cleaning of paper the careful selection of the applied wavelength, laser pulse energy and irradiation dose prevents the document and the paper substrate from unintended damage due to mechanical, thermal and photochemical effects.

10

Cavitation erosion of heterogeneous thin coatings produced by means of laser cladding

51%

Gireń B. G. , Jendrzejewski R. , Śliwiński G. , Wardach I.

Advances in Materials Science

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2003

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tom Vol. 3, nr 1(3)

18--26

EN

Cavitation erosion performance of heterogeneous, thin layers deposited on the structural carbon steel (45) by means of laser cladding was investigated. The samples were subjected to cavitation loading at the vibratory rig. The damage of tested surfaces at any moment of the erosion process were defined in twofold ways: by measuring the coating roughness and its reflectivity. A method of laser cladding applied in present work led to manufacturing of the surface layers of durable junction to the substrate and of high erosion resistance. The martensitic coatings enriched with Nb, Ni, Mn and some dispersed phases were considered. It was stated that heterogeneity of the materials made their performance worse.

11

Nanostructuring of thin Au films by means of short UV laser pulses

51%

Grochowska K. , Nedyalkov N. , Atanasov P. , Śliwiński G.

Opto-Electronics Review

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2011

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tom Vol. 19, No. 3

327-332

EN

The particle size distribution, morphology and optical properties of the Au nanoparticle (NP) structures for surface enhanced Raman signal (SERS) application are investigated in dependence on their preparation conditions. The structures are produced from relatively thin Au films (10-20 nm) sputtered on fused silica glass substrate and irradiated with several pulses (6 ns) of laser radiation at 266 nm and at fluencies in the range of 160-412 mJ/cm². The SEM inspection reveals nearly homogeneously distributed, spherical gold particles. Their initial size distribution of the range of 20-60 nm broadens towards larger particle diameters with prolonged irradiation. This is accompanied by an increase in the uncovered surface of the glass substrate and no particle removal is observed. In the absorption profiles of the nanostructures, the broad peak centred at 546 nm is ascribed to resonant absorption of surface plasmons (SPR). The peak position, halfwidth and intensity depend on the shape, size and size distribution of the nanostructured particles in agreement with literature. From peak intensities of the Raman spectra recorded for Rhodamine 6G in the range of 300-1800 cm⁻¹, the relative signal enhancement by factor between 20 and 603 for individual peaks is estimated. The results confirm that the obtained structures can be applied for SERS measurements and sensing.

12

Spektroskopia LIF oraz LIPS w diagnostyce i monitoringu laserowego oczyszczania dokumentów zabytkowych

51%

Ochocińska K. , Śliwiński G. , Kamińska A.

Zeszyty Naukowe Instytutu Maszyn Przepływowych Polskiej Akademii Nauk w Gdańsku

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2002

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tom nr 524/1483

139--156

EN

Techniques of laser induced spectroscopy: LIF and LIPS for diagnostics and monitoring of laser cleaning of old paper documents are proposed and experimental examples of applications are discussed. The LIF spectra of the model and historical paper samples are recorded under different conditions, i.e. pulsed excitation at 266 nm and 532 nm (fourth and second harmonic of Nd:YAG laser), and at the cryogenic (10K) and room temperature, before and after cleaning by means of the laser (532 nm, 0.5 J/cm/} or by the chemical method. The presence of contamination reveals a marked effect on the spectra which also depend strongly on the sample cleaning history. For excitation at 266 mn the characteristic band structure of the paper is observed in the LIF spectra in agreement with previous experiments. Results of the LIPS monitoring of laser cleaning (532 nm, 0.5 J/cm2) of an archive book from XIX cent, covered by a dark, dust-like layer of contamination confirms the usefulness of the applied diagnostic method. Sharp emission lines recorded at 589.4, 616.4, 780 nm (Na I); 612.5, 644.2, 646.5, 649.7, 671, 714.9, 720.2 nm (Ca I); and 766.5, 769.9 nm (Mg I) are ascribed to the surface pollutants and their intensity decrease with successive pulses. The broad band centred at 616 nm, originates most probably from the substrate fluorescence with superimposed contamination peaks.

13

Colorimetric study of the post-processing effect due to pulsed laser cleaning of paper

45%

Kamińska A. , Sawczak M. , Ciepliński M. , Śliwiński G. , Kosmowski B.

Optica Applicata

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2004

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tom Vol. 34, nr 1

121-132

EN

The effect of pulsed laser radiation applied for surface cleaning of historical paper samples from the 17th c. and also samples of newly made paper was investigated by means of measurement of the colorimetric parameters: lightness L*, chromaticity C* and yellowness G. For production of the new paper samples the same method and material (linters cellulose) as used in the past were adopted. An artificial sample contamination was simulated by a mixture of charcoal powder with dust. Surface cleaning was performed by means of a Nd:YAG laser (6 ns pulsewidth) at wavelengths from UV, visible, and near IR ranges (355, 532, and 1064 nm). The laser fluence was selected from the range between the ablation and damage thresholds (0.3-0.9 J/cm/sup 2/) of the substrate materials. The absolute differences Delta L*, Delta C* and Delta C indicate that the smallest changes of the original color parameters and the most effective surface cleaning occurred at 532 nm. Artificial aging equivalent to periods of 25 and 50 years resulted in negligible changes of the L* and G values of laser cleaned, laboratory soiled samples, while for non-soiled samples a marked enhancement of the surface darkening with time was observed. Changes in L*, C*, and G after the laser treatment at 355 nm and 1064 nm are ascribed to the photochemical damage of the cellulose fibers and to enhanced absorption of the laser radiation by soil particles.

14

Wybrane aspekty modelowania skomplikowanych powierzchni swobodnych z użyciem 3-osiowej obrabiarki CNC - model fragmentu ubytku kości czaszki

38%

Miechowicz S. , Śliwiński G. , Fudali P. , Kudasik T. , Markowska O. , Pacana J.

Zeszyty Naukowe Politechniki Poznańskiej. Budowa Maszyn i Zarządzanie Produkcją

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2011

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tom Nr 16

149-158

PL

W artykule opisano metodę zamodelowania skomplikowanego fragmentu modelu czaszki z wykorzystaniem frezarki trzyosiowej Roland MDX-40 używanej w Katedrze Konstrukcji Maszyn Politechniki Rzeszowskiej. Założeniami pracy były niskie koszty wytworzenia modelu przy zachowaniu wystarczającej dokładności. Do badań wykorzystano dane medyczne uzyskane w ramach współpracy z Katedrą Radiologii Collegium Medicum Uniwersytetu Jagiellońskiego w Krakowie. Największy nacisk w pracy położono na wykonanie rzeczywistego elementu protezy, bazując na jej wirtualnym projekcie STL. W pracy wskazano również na inne problemy, na jakie natrafiono w procesie frezowania modelu, a także określono zalety i ograniczenia przedstawionej metody. Praca potwierdziła możliwość wykonania modeli protez kostnych czaszki na prostej frezarce 3-osiowej z dokładnością wystarczającą do zastosowań medycznych. Kryterium ekonomiczne również zostało spełnione.

EN

The article presents method of modeling of complex part of cranial bone using three axis CNC milling machine Roland MDX-40 (Faculty of Mechanical Construction, Department of Mechanical Engineering and Aeronautics, Rzeszów University of Technology). The assumptions of the work were: the low costs of manufacturing of medical model and sufficient accuracy for clinical application. Medical data acquisition was supported by Chair of Radiology, Collegium Medicum of Jagiellonian University in Krakow. In this work the major emphasis was placed on manufacturing process of real prosthesis model based on its virtual STL project. To achieve this purpose the CAM software was used. In this work there are also pointed other problems connected with manufacturing, advantages and limitations of presented method. This work confirmed possibility of making cranium prostheses on simple three-axis milling machine with satisfactory accuracy for medical aims. Economical criterion was also fulfilled.