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1

Determination of the lipophilicity of some new thiosemicarbaside derivatives by reversed-phase thin-layer chromatography

Hawrył A., Kuśmierz E., Pisarczyk P., Wujec M., Waksmundzka-Hajnos M.

Acta Chromatographica

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2012

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Vol. 24, no. 2

271--290

EN

In this study, the chromatographic behavior of a newly synthesized series of 1,4-disubstituted thiosemicarbazide derivatives and products of their dehydrocyclization is presented. These compounds have been subjected to this study because they exhibit antimicrobial activity. The compounds have been chromatographed on RP-18 and on cyano-bonded silica chromatographic phases with eluents containing water and an organic modifier (methanol, dioxane, acetone, acetonitrile or tetrahydrofuran) of various concentrations. Statistically proved linear relationships between the retention parameter (RM) and the concentration of organic modifier in the mobile phase allow the extrapolation procedure to obtain RM0 for investigated compounds. The correlations between both the values of the intercept (RM0 ) and the slope (S) from the linear equation, taken as a measure of the lipophilicity, were calculated. The experimentally established parameters of lipophilicity (RM0 ) were compared with the log P values calculated by use of four different software packages. The values of the correlation coefficients of these relationships are higher for the cyanopropyl phase than for RP-18. Moreover, in this work the influences of different mobile phase modifiers and adsorbent layers on experimentally obtained lipophilicity parameters were analyzed and compared. Generally, the best correlations were obtained for systems with the cyanopropyl-bonded stationary phase in comparison with RP-18.

2

Fault injection approach towards dependability analysis in real time operating systems

Gawkowski P., Grochowski K., Pisarczyk P.

Pomiary Automatyka Kontrola

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2011

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R. 57, nr 8

830-832

EN

The paper presents the fault injection approach applicable for dependability evaluation of real-time systems. The developed fault injection environment, called InBochs, is based on modified system emulator Bochs. It is highly flexible in terms of fault specification and results observability reflecting in rich feedback information for a target system developer. The low overhead of the InBochs fulfills tight requirements for RT-system evaluation testbeds. The paper describes the methodology of dependability evaluation basing on an exemplary process control task.

PL

Wszechobecność systemów wbudowanych i czasu rzeczywistego niesie za sobą potrzebę analizy ich wiarygodności. Dotyczy to nie tylko systemów w zastosowaniach krytycznych (jak aeronautyka, czy sterowanie procesów przemysłowych), gdzie głównym aspektem jest bezpieczeństwo, ale także popularnych urządzeń życia codziennego, od których użytkownicy również oczekują określonego poziomu niezawodności i dostępności. Niezbędna jest więc analiza odporności systemów na różnego rodzaju zakłócenia, m.in. na rosnące niebezpieczeństwo zakłóceń przemijających w systemie cyfrowym, w szczególności tzw. SEU (ang. Single Event Upsets [1], efektem których mogą być przekłamania wartości logicznych w elementach pamięci). Omówiono szereg aspektów analizy eksperymentalnej przy wykorzystaniu techniki programowej symulacji błędów w kontekście badań systemów czasu rzeczywistego oraz przedstawiono system InBochs, który może być zastosowany m.in. do eksperymentalnej analizy wiarygodności systemów wbudowanych oraz czasu rzeczywistego. Bazuje on na programowym emulatorze systemu komputerowego Bochs [5]. Spośród innych rozwiązań ([2] i referencje) InBochs umożliwia m.in. abstrakcję czasu ukrywającą narzuty symulatora oraz język skryptowy symulacji błędów. Jego praktyczna użyteczność została potwierdzona eksperymentami dla dwóch różnych systemów czasu rzeczywistego (RTAI [7, 9] oraz Phoenix [8]) realizujących zadanie sterownika GPC w wersji analitycznej dla procesu reaktora chemicznego (opis w [6] i referencje).

3

Plasma jet generation by flyer disk collision with massive target

Kasperczuk A., Pisarczyk T., Borodziuk S., Gus'kov S. Y., Ullschmied J., Krousky E., Masek K., Pfeifer M., Rohlena K., Skala J., Kalal M., Limpouch J., Pisarczyk P.

Optica Applicata

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2007

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Vol. 37, nr 1-2

73-82

EN

In this paper, results from experiments with Al flyer targets (disks with a diameter of 300 mm and a thickness of 6 mm) accelerated at first to high velocities by PALS iodine laser pulses (with an energy of 130 J, pulse duration of 400 ps, a wavelength of 1.315 mm, and laser spot diameter of 250 mm), subsequently creating craters after their collisions with massive Al targets (placed at a distance of the order of 200 mm) are presented. To measure the plasma density evolution a three frame interferometric system was employed. The experimental results demonstrate that the flyer disk-massive target collision generates an axial plasma jet corresponding to a flat shock wave propagating in a massive target. This form of the shock wave was deduced from a crater trapezoidal shape which was reconstructed by means of crater replica technique.

4

High power laser interaction with single and double layer targets

Borodziuk S., Demchenko N. N., Guskov S. Y., Jungwirth K., Kalal M., Kasperczuk A., Kondrashov V. N., Kralikova B., Krousky E., Limpouch J., Masek K., Pisarczyk P., Pisarczyk T., Pfeifer M., Rohlena K., Rozanov V.B., Skala J., Ullschmied J.

Optica Applicata

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2005

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Vol. 35, nr 2

241-262

EN

Results of extended complementary experimental and computer simulation studies of craters formation produced by high power lasers in single and double layer targets are presented. The experimental investigation was carried out using the PALS (Prague Asterix Laser System) facility working with two different laser beam wavelengths: L(lambda)1 = 1.315 žm and L3 = 0.438 žm. Two types of targets made of Al were used: single massive targets and double targets consisting of foils or disks (6 and 11 žm thick for both cases) placed in front of the massive target at distances of 200 and 500 žm. The targets were illuminated by laser energies EL= 130, 240 and 390 J always focused with diameter of 250 žm. In all experiments performed the laser pulse duration was equal to 400 ps. The 3-frame interferometry was employed to investigate the plasma dynamics by means of the electron density distribution time development, as well as the disks and foil fragments velocity measurements. Dimensions and shapes of craters were obtained by crater replica technology and microscopy measurement. Experimental results were complemented by analytical theory and computer simulations to help their interpretation. This way the values of laser energy absorption coefficient, ablation loading efficiency and efficiency of energy transfer, as well as 2-D shock wave generation at the laser-driven macroparticle impact, were obtained from measured craters parameters for both wavelengths of laser radiation. Computer simulations allowed us to obtain an energy absorption balance of incident laser energy for both wavelengths employed.

5

Investigation of plasma ablation and crater formation processes in the Prague Asterix Laser System laser facility

Borodziuk S., Kasperczuk A., Pisarczyk T., Gus'kov S., Ullschmied J., Kralikova B., Rohlena K., Skala J., Kalal M., Pisarczyk P.

Optica Applicata

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2004

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Vol. 34, nr 1

31-42

EN

The present investigation of the processes of ablative plasma generation and formation of craters was carried out at the Prague Asterix Laser System (PALS) iodine laser facility. Experiments were performed with broad range of laser beam intensities (1013-1016 W/cm2), focal spot radii (35–600 mm), and two laser wavelengths (l1 = 1.315 mm and l3 = 0.438 mm). The laser beam was focused on the surface of the massive solid aluminum targets. The main goal of our study was to estimate conversion efficiency of the laser beam energy into the energy of shock waves for different mechanisms of laser beam–target interaction. The expansion of plasma generated as a result of the interaction process was observed by means of the 3-frame interferometry. Dimensions and shapes of the craters were determined using optical microscopy and wax-replica technique.

6

Application of the 3-frame interferometry and the crater replica method for investigation of laser accelerated macroparticles interacting with massive targets in the Prague Asterix Laser System (PALS) experiment

Borodziuk S., Kasperczuk A., Pisarczyk T., Demchenko N.N., Gus’kov S., Rozanov V. B., Kalal M., Limpouch J., Ullschmied J., Rohlena K., Skala J., Kondrashov V. N., Pisarczyk P.

Optica Applicata

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2004

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Vol. 34, nr 3

385-403

EN

In the present paper results from our experiments with macroparticles, accelerated at first to high speeds by the PALS iodine laser and subsequently hitting massive targets and creating craters, are presented. The main aim of these investigations concerned the influence of wavelength on the efficiency of macroparticles acceleration and creation of craters. To this end, two different harmonics of the PALS laser beam (l1 = 1.315 mm and l3 = 0.438 mm) and several types of targets (simple massive planar Al targets as well as much more elaborated double targets consisting of 6 mm thick Al foils or disks placed in front of the massive target at the distance of either 200 mm or 500 mm) were used. All these targets were irradiated by the iodine laser beam with its parameters very much the same for both harmonics: the energy of 130 J, the focal spot diameter of 250 mm, and the pulse duration of 400 ps. Velocities of accelerated extracted foil fragments or disks as well as electron density distributions of plasma streams were determined by means of the 3-frame interferometry. Shapes and volumes of craters were obtained employing the crater acetate cellulose replica technology and microscopy measurements. The data from these experiments provided valuable information concerning the ablative plasma generation and crater creation processes.

7

Experimental and theoretical investigations of crater formation in an aluminium target in a PALS experiment

Borodziuk S., Doskach I., Gus'kov S., Jungwirth K., Kálal M., Kasperczuk A., Kralikova B., Krousky E., Limpouch J., Masek K., Pfeifer M., Pisarczyk P., Pisarczyk T., Rohlena K., Rozanov V., Skala J., Ullschmied J.

Nukleonika

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2004

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Vol. 49, nr 1

7-14

EN

Experimental and theoretical results of investigations of the iodine laser - Al solid target interactions on the PALS (Prague Asterix Laser System) facility are presented. The experimental investigations of laser interaction with massive Al targets devoted to shock wave propagation in solids and crater formation physics are presented. Experiments were performed with the use of high intensity laser pulses (1013 15 W/cm2) for two laser wavelengths (0.438 mi m and 1.315 mi m) and four laser beam radii (from 35 mi m up to 600 ěm). The crater dimensions were measured using optical microscopy and a wax-replica technique. Plasma expansion out of the target was measured via three-frame interferometry. Theoretical model of the postpulse crater formation by the shock wave propagating and decaying in solids after the end of the laser pulse is presented and applied for the explanation of the results obtained in experiments.