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1

Ocena właściwości śrub w stykach doczołowych

Kawecki Paweł

Inżynieria i Budownictwo

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2025

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R. 81, nr 3

213--216

PL

Przedstawiono metody oceny właściwości konstrukcyjnych śrub w połączeniach doczołowych belek. Zwrócono uwagę na zmianę zachowania się śrub w zależności od długości gwintu w części zaciskowej, wpływu metody badania i modelowania na wnioskowanie o cechach wytrzymałościowych łączników.

EN

Methods for assessing the structural properties of bolts in beam endplate connections are presented. Attention is paid to the change in bolt behaviour depending on the length of the thread in the clamping part, the influence of the testing method and modelling on the conclusions about the strength properties of the fasteners.

2

Otrzymywanie wosków poliolefinowych w procesie termicznej degradacji. Część 2, Wpływ struktury surowca na właściwości wosku polietylenowego

Kowalska Justyna, Grzymek Marek, Czaja Krystyna

Przemysł Chemiczny

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2024

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T. 103, nr 3

368--374

PL

Gatunki polietylenów dużej gęstości (HDPE), małej gęstości (LDPE) oraz linowych polietylenów małej gęstości (LLDPE) wytypowane na podstawie wcześniej wykonanych badań molekularno-strukturalnych i termicznych poddano procesowi termicznej degradacji w ustalonych warunkach w kierunku uzyskania wosków polietylenowych. Otrzymane produkty poddano szczegółowej analizie, a uzyskane wyniki porównano z odpowiednimi wynikami uzyskanymi dla użytych surowców. Na tej podstawie przedyskutowano mechanizm tworzenia wosków polietylenowych w procesie termicznej degradacji poliolefin.

EN

Polyolefin waxes were produced by thermal degrdn. of high-d. low-d. and linear low-d. polyethylenes and studied for their structure by IR spectroscopy with Fourier transformation. The structures were compared with structures of resp. raw materials. The thermal degrdn. was confirmed as an efficient method for prodn. of polyolefin waxes.

3

Increasing efficiency of technological processes in oil production based on innovative rheotechnologies

Mammadova Yevgeniya V.

Nafta-Gaz

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2024

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R. 80, nr 8

488--494

EN

Numerous studies by various authors have been devoted to gas lift wells. The scientific literature has addressed issues of increasing production of both Newtonian and non-Newtonian oils. Despite these efforts, the efficiency of the gas lift method remains relatively low, necessisating novel approaches. One of the methods to increase the productivity of gas lift wells may be the use of innovative rheotechnologies. Rheotechnology laverages knowledge about the rheological properties of formation fluids to address specific technological problems. This paper describes studies of non-Newtonian oils, their rheological properties, and their impact on the technical and economic indicators of gas lift wells. The analysis showed that by studying the formation of the non-Newtonian structure of oil, it is possible to influence its relaxation properties, and thus obtain the movement of an abnormal oil (anomalous fluid), both in the bottom-hole zone of the well and in the lifting pipes. The results of experimental studies showed that viscoelastic crude oil flowing into the wellbore contains an increased volume of reservoir gas, which, along with the injected working agent, perform additional work in lifting gas-liquid mixtures to the surface. During gas lifting operations, phenomena such as breakthrough and slippage of the working agent can be observed. Addressing all these factors enables better control over gas lift well operations and, consequently, improves the efficiency of the tecnological processes.

PL

Wielu autorów poświęciło swoje prace tematyce odwiertów eksploatowanych z wykorzystaniem metody sprężonego gazu. W literaturze naukowej poruszono kwestie zwiększenia wydobycia zarówno ropy o właściwościach newtonowskich, jak i nienewtonowskich. Pomimo tych wysiłków wydajność metody z zastosowaniem sprężonego gazu pozostaje stosunkowo niska, co wymaga opracowania nowych rozwiązań. Jedną z metod zwiększenia wydajności odwiertów eksploatowanych za pomocą sprężonego gazu może być zastosowanie innowacyjnych technologii reologicznych. Technologia reologiczna wykorzystuje wiedzę o właściwościach reologicznych płynów złożowych do rozwiązywania konkretnych problemów technologicznych. W artykule opisano badania nad ropą o właściwościach nienewtonowskich, jej właściwościami reologicznymi oraz ich wpływem na wskaźniki techniczne i ekonomiczne odwiertów eksploatowanych metodą sprężonego gazu. Przeprowadzona analiza wykazała, że badając proces formowania się nienewtonowskiej struktury ropy naftowej można wpływać na jej właściwości relaksacyjne, a tym samym uzyskać ruch nietypowej ropy naftowej („cieczy anomalnej”), zarówno w strefie przyodwiertowej, jak i w rurach wydobywczych. Wyniki badań eksperymentalnych wykazały, że lepkosprężysta ropa naftowa wpływająca do odwiertu charakteryzuje się zwiększoną objętością gazu złożowego, który wraz z wtryskiwanym czynnikiem roboczym pomaga wypychać mieszaniny gazu i cieczy na powierzchnię. Podczas operacji z zastosowaniem gazodźwigu można zaobserwować zjawiska takie jak przebicie i poślizg czynnika roboczego. Uwzględnienie wszystkich tych czynników umożliwia lepszą kontrolę nad operacjami podnoszenia gazu, a w konsekwencji poprawia efektywność procesów technologicznych.

4

Experimental Investigation of the Structural Performance of Concrete Containing Cellulose Fibers and the Anti-corrosive Effect of Green Corrosion Inhibitors

Ramshankar Pushpanathan, Ganeshan Pushpanathan, Raja Kandhasamy, NagarajaGanesh Balasubramanian

Civil and Environmental Engineering Reports

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2024

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Vol. 34, no. 2

22--44

EN

This research was aimed to find the structural behaviour of Calotropis procera fibres added concrete and the effect of Azadirachta indica leaf slurry blended to concrete and exposed to seawater. Conventional and fibre reinforced concrete samples fabricated keeping the curing time as 7, 14 and 28 dayswere subjected to compression, split tensile, rebound hammer and ultrasonic pulse velocity test. Increase in curing time increased the structural properties and Calotropis procerafibres added samples produced respectively 19.5%, 15%, 10.3 and 14.5% improvement in the compression, tensile, rebound hammer and ultrasonic pulse velocity values. These fibres reduced the brittleness of the specimen and avoided unprecedented failures. Accelerated corrosion and gravimetric mass loss test conducted to estimate the anti-corrosive property of Azadirachta indica leaf slurry showed decrease in corrosion rate. The corrosion rate of concrete samples without and with inhibitors was 0.0654 ± 0.008 and 0.056 ± 0.011 mm/year respectively evincing the anti-corrosive effects of Azadirachta indica leaves. Thus green materials are compatible with concrete and can be used in making sustainable concrete structures.

5

Structural and optical properties of aluminium nitride thin films fabricated using pulsed laser deposition and dc magnetron sputtering on various substrates

Virt Ihor, Potera Piotr, Wisz Grzegorz, Dziedzic Andrzej, Cieniek Bogumił, Lopatynskyi Ivan, Frugynskyi Marian

Advances in Materials Science

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2024

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Vol. 24, nr 1(79)

5--16

EN

Aluminium nitride thin films were fabricated using pulsed laser deposition and DC magnetron sputtering. Different technological parameters and the effects of different substrates on the optical and structural parameters of AlN samples were studied. An X-ray diffraction study was performed for the layer deposited on the Si3N4 substrate. A high-energy electron diffraction study was also carried out for the layer deposited on a KCl substrate. Transmission spectra of layers on quartz, sapphire, and glass substrates were obtained. An evaluation of the optical band gap of the obtained layers was carried out (Eg form 3.81 to 5.81 eV) and the refractive index was calculated (2.58). The relative density of the film (N1TN-AlN sample) is 1.26 and was calculated using the Lorentz-Lorentz relationship. Layers of aluminium nitride show an amorphous character with a polycrystalline region. It was shown that the properties of AlN films strongly depend on the method, growth conditions, and substrate used.

6

Właściwości strukturalne i fizykomechaniczne błon z poli(chlorku winylu) barwionych pigmentami kadmowymi

Makarewicz Edwin, Tworek Magdalena, Lamkiewicz Jan, Ziółkowska Dorota, Majewska Kinga, Siekierka Przemysław

Przemysł Chemiczny

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2020

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T. 99, nr 1

113--119

PL

Badano zmiany barwy, struktury, temperatury mięknienia i właściwości wytrzymałościowych błon zawierających pigmenty kadmowe przed i po ich naświetlaniu promieniowaniem UV. Pigmenty miały barwy: żółtą, oranżową oraz czerwoną i składały się z siarczku kadmu, siarczku cynku oraz selenku kadmu. Do barwienia błon użyto pigmentów oczyszczonych oraz po ich obróbce w środowisku kwaśnym lub zasadowym. Błony otrzymano przez żelowanie plastizoli poli(chlorku winylu). Określono składowe barwy RGB błon, właściwości spektroskopowe, stopień krystaliczności, temperaturę mięknienia i wytrzymałość oraz wydłużenie względne podczas rozciągania. Promieniowanie UV spowodowało zmianę właściwości fizycznych, fizykochemicznych oraz mechanicznych błon w wyniku przebiegu różnych procesów degradacji pigmentów i polimerowej błony.

EN

Eight com. CdS, ZnS and CdSe-contg. Cd pigments were purified by AcOBu extn. and treated with H₂SO₄ or NaOH. They were dried at 60°C and mixed in a mortar with 8.3, 14.3 and 20% by mass of PVC plastisol then vented for 24 h, poured on a flat surface and dried at 140°C for 1 h to a gel. The membranes were irradiated with UV. The changes in membrane color, degree of crystallinity, softening point, tensile strength and relative elongation before and after UV irradn. were detd. The UV irradn. resulted in a deterioration of membrane properties and degrdn. of both pigments and polymer.

7

Sputtering pressure influenced structural, electrical and optical properties of RF magnetron sputtered MoO3 films

Subbarayudu S., Reddy K. Venkata Subba, Uthanna S.

Materials Science Poland

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2020

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Vol. 38, No. 1

41--47

EN

MoO3 films were deposited by RF magnetron sputtering technique on glass and silicon substrates held at 473 K by sputtering of metallic molybdenum target at an oxygen partial pressure of 4 x 10-2 Pa and at different sputtering pressures in the range of 2 Pa to 6 Pa. The influence of sputtering pressure on the structure and surface morphology, electrical and optical properties of the MoO3 thin films was studied. X-ray diffraction studies suggest that the films deposited at a sputtering pressure of 2 Pa were polycrystalline in nature with mixed phase of α- and β-phase MoO3, while those formed at sputtering pressure of 4 Pa and above were of a-phase MoO3. Scanning electron micrographs showed a decrement in the size of the particles and their shapes changed from needle like structure to dense films with the increase of sputtering pressure. Fourier transform infrared spectroscopic studies confirmed the presence of characteristic vibration modes of Mo=O, Mo–O and Mo–O–Mo related to MoO3. Electrical resistivity of the MoO3 films decreased from 6.0 x 104 Ωcm to 2 X 104 Ω∙cm with an increase of sputtering pressure from 2 Pa to 6 Pa, respectively. Optical band gap of the films decreased from 3.12 eV to 2.86 eV with the increase of sputtering pressure from 2 Pa to 6 Pa, respectively.

8

Effect of Cd precursor on structure and optical properties of spin coated Zn0.9Cd0.1O films for optoelectronics applications

Arora Isha, Kumar Praveen, Sathiaraj T. S.

Materials Science Poland

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2020

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Vol. 38, No. 3

459--464

EN

The development of transparent conducting oxide materials has gained an increased interest in the scientific community for developing efficient low cost optoelectronic devices. The effect of Cd precursor on structural and optical properties of sol-gel synthesized Zn0.9Cd0.1O nanostructured films has been studied by using XRD, AFM, optical absorption and emission spectroscopic techniques. X-ray diffraction confirms the hexagonal wurtzite crystal structure of the deposited films and the relative intensity of diffraction peaks has been observed with different cadmium salts. The granular surface morphology of the synthesized films has been observed from AFM measurements. The optical transmission, band gap and luminescence intensity was found to change for different cadmium salts. These results are very important for developing new materials for optoelectronic applications.

9

Właściwości powierzchniowe i strukturalne tytanowej powłoki osadzanej tarciowo na podłożu ceramicznym AlN

Chmielewski Tomasz, Golański Dariusz, Hudycz Michał, Sałacinski Tadeusz, Świercz Rafał

Przemysł Chemiczny

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2019

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T. 98, nr 2

208--213

PL

Przedstawiono wybrane właściwości tytanowej powłoki metalizacyjnej wytworzonej na ceramice AIN metodą tarciową, opierając się na mechanizmie powstawania połączenia, w którym energia tarcia kinetycznego jest bezpośrednio zamieniana na ciepło i dostarczana w ściśle określonej ilości do powstającego połączenia między powłoką a podłożem. Opisano oryginalną metodę tarciowego osadzania cienkich powłok metalizacyjnych na ceramice i scharakteryzowano tytanową powłokę metalizacyjną pod względem budowy fazowej, właściwości metalograficznych, morfologii powierzchni, struktury stereometrycznej powierzchni oraz grubości.

EN

AlN ceramics was coated with Ti by friction-surfacing method where the energy of kinetic friction was directly transformed into heat and delivered in its sp. amt. directly to the formed joint between Ti layer and substrate material. The coating was studied for face structure, metallog. properties, morphol., stereostructure and thickness. The coating was 3-6 μm thick, defect-free and rough enough (0.404 and 1.95 μm) to be soldered to metals.

10

Structural, morphological, optical and diode properties of chemical bath deposited nano-structured CdS thin films using EDTA as a complexing agent

Vidhya S. N., Karunakaran R. T.

Materials Science Poland

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2019

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Vol. 37, No. 3

317--323

EN

CdS thin films with (1 1 1) orientation were prepared by chemical bath deposition technique at 80±5 °C using the reaction between NH4OH, CdCl2 and CS(NH2)2. The influence of annealing temperature varying from 150 °C to 250 °C was studied. X-ray diffraction studies revealed that the films are polycrystalline in nature with cubic structure. Various parameters, such as dislocation density, stress and strain, were also evaluated. SEM analysis indicated uniformly distributed nano-structured spherically shaped grains and net like morphology. Optical transmittance study showed the wide transmittance band and absence of absorption in the entire visible region. I-V characterization of p-Si/n-CdS diode and photoluminescence studies were also carried out for the CdS films.

11

Bleached Kraft Pulps From Blends of Wood and Hemp. Part II – Structural, Optical and Strength Properties of Pulps

Danielewicz Dariusz, Surma-Ślusarska Barbara

Fibres & Textiles in Eastern Europe

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2019

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Vol. 27, no. 2 (134)

111--116

EN

The breathability, strength, structural and optical properties of bleached kraft pulps from blends of birch or pine with hemp stalks in a proportion of 80/20 weight % were studied. It was found that these pulps generally have comparable properties to those of bleached pulps from birch and pine. The properties of bleached pulps produced from 80/20 weight % blends of pine or birch with hemp woody-core such as the breaking length, burst, and light scattering proved to be comparable or better than those of bleached pulps from wood. However, the replacement of a part of birch or pine with hemp-woody core negatively affected their bulk, air-resistance, and tearing resistance. Taking into consideration the results presented in Part I and Part II of the study, it can concluded that hemp stalks are better fibrous raw material for the manufacturing of papermaking intermediates partially free of wood fibres than hemp woody-core.

PL

W pracy zbadano podatność na mielenie oraz właściwości strukturalne, optyczne i wytrzymałościowe bielonych mas celulozowych wytworzonych z mieszanek drewna brzozy i sosny z łodygami konopnymi o udziale tych łodyg odpowiednio 80 i 20% wag. Stwierdzono, że właściwości tych mas celulozowych są zbliżone do właściwości bielonych mas celulozowych brzozowej i sosnowej. Co się tyczy bielonych mas celulozowych z mieszanek drewna brzozy i sosny z drewnikiem konopnym to ich właściwości takie jak: samozerwalność, przepuklenie i zdolność do rozpraszania światła również okazały się porównywalne lub nawet lepsze, niż w przypadku bielonych mas brzozowej i sosnowej. Zastąpienie części drewna drewnikiem konopnym wpływało jednak ujemnie na objętość właściwą, przepuszczalność powietrza, a także odporność na przedarcie arkusików mas celulozowych. Biorąc pod uwagę wyniki przedstawione w części I i II pracy, można zatem stwierdzić, że łodygi konopne są lepszym surowcem włóknistym do wytwarzania częściowo wolnych od włókien drewna papierniczych półproduktów włóknistych, niż drewnik konopny.

12

Wpływ parametrów procesu technologicznego na właściwości cienkich warstw na bazie miedzi

Rogala Jacek, Wojcieszak Damian, Pastuszek Roman, Mańkowska Ewa

Elektronika : konstrukcje, technologie, zastosowania

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2019

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Vol. 60, nr 7

31--33

PL

W pracy przedstawiona została analiza wpływu parametrów procesu technologicznego wytwarzania cienkich warstw tlenków miedzi na ich właściwości strukturalne, optyczne oraz elektryczne. Badaniu poddane zostały warstwy wytworzone za pomocą metody stałoprądowego rozpylania magnetronowego w atmosferze mieszaniny O₂:Ar o zawartości O₂ wynoszącej odpowiednio 75% oraz 100%. Właściwości strukturalne badanych warstw określone zostały na podstawie badania metodą dyfrakcji rentgenowskiej. Właściwości optyczne scharakteryzowano na podstawie pomiaru transmisji światła, a elektryczne na podstawie charakterystyk prądowo-napięciowych. Badanie metodą XRD wykazało, że uzyskano warstwy CuO (tlenku miedzi II) w postaci tenorytu o średnim rozmiarze krystalitów wynoszącym około 13 nm. Badanie właściwości optycznych wykazało, że nie ma różnicy w transmisji światła dla promieniowania krótszego niż około 600 nm. Nieznaczne różnice zauważalne między warstwami widoczne są powyżej tej długości. Średnia wartość transmisji dla długości fali λ = 550 nm wynosiła 35%. Badanie właściwości elektrycznych wykazało, że warstwa naniesiona w mieszaninie O₂:Ar zawierającej 75% O₂ miała rezystancję wynoszącą około 17 kΩ podczas gdy rezystancja warstwy wytworzonej w atmosferze wyłącznie tlenowej wynosiła około 5 kΩ.

EN

The paper presents an analysis of the impact of the parameters of the technological process of copper oxides thin films on their structural, optical and electrical properties. Investigated films were deposited using DC magnetron sputtering method in the atmosphere of the O₂:Ar mixture with an O₂ content of 75% and 100% respectively. The structural properties of the investigated films were determined based on the X-ray diffraction method. Optical properties were characterized on the basis of light transmission measurements, and electrical properties based on current- -voltage characteristics. The XRD showed that CuO (copper oxide II) films were obtained in the form of a tenorite with an average crystallite size of about 13 nm. The investigation of the optical properties showed that there is no difference in light transmission for wavelength shorter than approximately 600 nm. Slight differences between the layers are visible above this length. The average transmission value at wavelength λ = 550 nm was 35%, so these layers can be used in transparent electronics. Testing of electrical properties showed that the layer deposited in the O₂:Ar gas mixture containing 75% of O₂ had a resistance of approximately 17 kΩ, when the resistance of the layer prepared in a pure oxygen atmosphere of approximately 5 kΩ.

13

Ocena parametrów strukturalnych dolomitów z kopalni rud miedzi przy wykorzystaniu metod densymetrycznych i porozymetrycznych

Kozieł K., Pajdak A.

Prace Instytutu Mechaniki Górotworu PAN

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2018

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T. 20, nr 4

327--333

PL

W artykule przedstawiono wyniki badań strukturalnych trzech próbek dolomitów (PR-1, PR-2, PR-3) z polskich kopalni rud miedzi. Wykorzystano w tym celu metody piknometrii helowej i quasicieczowej oraz porozymetrii rtęciowej i gazowej. Najwyższe wartości porowatości całkowitej i otwartej, wyznaczone metodami densymetrycznymi, posiadała próbka PR-1, a najniższe wartości próbka PR-3. Określona w próbce PR-1 porowatość całkowita wyniosła 18%, w tym porowatość otwarta blisko 17,6%. W PR-3 natomiast wartości tych parametrów wyniosły odpowiednio 9,5% oraz 8,4%. Dolomit PR-1 miał najbardziej rozbudowaną strukturę porową w całym zakresie porowatości, co potwierdziły analizy porozymetryczne. Próbki posiadały wartości całkowitej objętości makroporów w zakresie 6-34 mm3/g i powierzchni właściwej makroporów, w zakresie 0,4-0,8 m2/g. W zakresie najdrobniejszych porów, powierzchnia właściwa wyniosła od 2,0 m2/g do 3,7 m2/g. Objętość mezoporów w przebadanych dolomitach mieściła się w zakresie 6,1-9,4 mm3/g. Najniższą porowatością określoną porozymetrycznie cechował się dolomit PR-3. Charakterystyka strukturalna dolomitów może stanowić ważny element w ocenie parametrów gazogeodynamicznych dolomitów.

EN

The article presents the results of structural analyses of three dolomite samples (PR-1, PR-2, PR-3) from Polish copper ore mines. Helium pycnometry, qasi-fluid pycnometry, mercury porosimetry and gas porosimetry were used for this purpose. The highest values of total and open porosity, determined by densimetric methods, were found in sample PR-1 and the smallest in sample PR-3. The porosity determined for sample PR-1 was 18% and open porosity amounted to 17.6%. The values of the same parameters in PR-3 were 9.5% and 8.4% respectively. Dolomite PR-1 had the most developed pore structure in the whole range of porosity, which was confirmed by porosimetric analyses. The total pore volume of the samples was in the range of 6-34 mm3/g and the surface area was in the range of 0,4-0,8 m2/g. The surface area of the smallest pores was from 2,0 m2/g to 3,7 m2/g. The volume of mesopores in the dolomites tested was in the range of 6,1-9,4 mm3g. The lowest porosity, determined by porosimetry, was found in dolomite PR-3. The structural characteristics of dolomites may be an important element in the evaluation of gasogeodynamic parameters of dolomites.

14

Synthesis and characterization of Ag-chalcogenide nanoparticles for possible applications in photovoltaics

Chand S., Sharma P.

Materials Science Poland

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2018

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Vol. 36, No. 3

375--380

EN

Bottom-up technique has been used to synthesize Ag-chalcogenide nanoparticles. This work reports on the synthesis of Ag2Se by varying the molar ratio of capping agent and pH of the solution. The synthesized nanoparticles have been characterized in terms of structural parameters using X-ray diffraction. By this technique, various parameters such as crystallite size, dislocation density and strain of the nanoparticles were calculated. The crystallite size decreased with the increase in pH of the solution. The optical characterization was carried out by UV-Vis-NIR spectrophotometer. With the decrease in the crystallite size, a blue shift in the absorption peak of the nanoparticles was observed. These properties are suitable for energy harvesting with the help of photovoltaics.

15

Structural and optical characterization of annealed As30Te60Ga10 thin films prepared by thermal evaporation technique

Abd-Elnaiem A. M., Mohamed M., Hassan R. M., Abdel-Rahim M. A., Abu-Sehly A. A., Hafiz M. M.

Materials Science Poland

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2018

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Vol. 36, No. 2

193--202

EN

Effect of annealing temperature on the structural and optical properties of As30Te60Ga10 thin film was studied using various techniques such as differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The DSC analysis revealed that the As30Te60Ga10 glass has a single glass transition and crystallization peak while XRD results confirmed that the as-prepared and annealed films have crystalline nature. The coexistence of the crystalline phases in the investigated films could be attributed to the formation of orthorhombic As, hexagonal Ga7Te10, and monoclinic As2Te3 phases. It was found that the average crystallite size and optical parameters of the studied films depend on the annealing temperature. For example, the optical band gap decreased from 1.54 eV to 1.11 eV as the annealing temperature increased from 300 K to 433 K.

16

Nanostructured device based on coated ZnO layer as a window in solar cell applications

Mokhtari H., Benhaliliba M., Boukhachem A., Aida M. S., Ocak Y. S.

Materials Science Poland

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2018

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Vol. 36, No. 4

570--583

EN

This work highlights some physical properties related to the influence of aluminum, tin and copper incorporation on nanostructured zinc oxide (ZnO:M; M:Al, Sn and Cu) thin films prepared by ultrasonic spray pyrolysis technique (USP) on glass substrate at 350±5 °C. For the as-grown layers, M- to Zn-ratio was fixed at 1.5 %. The effects of metal doping on structural, morphological, optical and electrical properties were investigated. X-ray diffraction pattern revealed that the as-prepared thin films crystallized in hexagonal structure with (0 0 2) preferred orientation. The surface topography of the films was performed by atomic force microscopy. AFM images revealed inhibition of grain growth due to the doping elements incorporation into ZnO matrix, which induced the formation of ZnO nanoparticles. Optical measurements showed a high transparency around 90 % in visible range. Some optical parameters, such as optical band gap, Urbach energy, refractive index, extinction coefficient and dielectric constant were studied in terms of doping element. Particularly, dispersion of refractive index was discussed in terms of both Cauchy and single oscillator model proposed by Wemple and DiDomenico. Cauchy parameters and single oscillator energy E0 as well as dispersion energy Ed were calculated. Finally, electrical properties were investigated by means of electrical conductivity and Hall effect measurements. The measurements confirmed n type conductivity of the prepared thin films and a good agreement between the resistivity values and the oxidation number of doping element. The main aim of this work was the selection of the best candidate for doping ZnO for optoelectronics applications. The comparative study of M doped ZnO (M:Al, Sn and Cu) was performed. High rectifying efficiency of the Al/n-ZnO/p-Si/Al device was achieved and non-ideal behavior was revealed with n > 4.

17

Influence of magnetron powering mode on various properties of TiO2 thin films

Wiatrowski A., Mazur M., Obstarczyk A., Kaczmarek D., Pastuszek R., Wojcieszak D., Grobelny M., Kalisz M.

Materials Science Poland

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2018

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Vol. 36, No. 4

748--760

EN

In this paper, comparative studies on the structural, surface, optical, mechanical and corrosion properties of titanium dioxide (TiO2) thin films deposited by continuous and sequential magnetron sputtering processes were presented. In case of continuous process, magnetron was continuously supplied with voltage for 90 min. In turn, in sequential process, the voltage was supplied for 1 s alternately with 1 s break, therefore, the total time of the process was extended to 180 min. The TiO2 thin films were crack free, exhibited good adherence to the substrate and the surface morphology was homogeneous. Structural analysis showed that there were no major differences in the microstructure between coatings deposited in continuous and sequential processes. Both films exhibited nanocrystalline anatase structure with crystallite sizes of ca. 21 nm. Deposited coatings had high transparency in the visible wavelength range. Significant differences were observed in porosity (lower for sequential process), scratch resistance (better for sequential process), mechanical performance, i.e. hardness:elastic modulus ratio (higher for sequential process) and corrosion resistance (better for sequential process).

18

A geometric approach to structural model matching by output feedback in linear impulsive systems

Zattoni E.

International Journal of Applied Mathematics and Computer Science

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2018

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Vol. 28, no. 1

25--38

EN

This paper provides a complete characterization of solvability of the problem of structural model matching by output feedback in linear impulsive systems with nonuniformly spaced state jumps. Namely, given a linear impulsive plant and a linear impulsive model, both subject to sequences of state jumps which are assumed to be simultaneous and measurable, the problem consists in finding a linear impulsive compensator that achieves exact matching between the respective forced responses of the linear impulsive plant and of the linear impulsive model, by means of a dynamic feedback of the plant output, for all the admissible input functions and for all the admissible sequences of jump times. The solution of the stated problem is achieved by reducing it to an equivalent problem of structural disturbance decoupling by dynamic feedforward. Indeed, this latter problem is formulated for the so-called extended linear impulsive system, which consists of a suitable connection between the given plant and a modified model. A necessary and sufficient condition for the solution of the structural disturbance decoupling problem is first shown. The proof of sufficiency is constructive, since it is based on the synthesis of the compensator that solves the problem. The proof of necessity is based on the definition and the geometric properties of the unobservable subspace of a linear impulsive system subject to unequally spaced state jumps. Finally, the equivalence between the two structural problems is formally established and proven.

19

Influence of calcination temperature on optical and structural properties of TiO2 thin films prepared by means of sol-gel and spin coating

Tański T., Matysiak W., Kosmalska D., Lubos A.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2018

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Vol. 66, nr 2

151--156

EN

In this study, ceramic TiO2 thin films were prepared on glass substrates using sol-gel and spin-coating methods from the TNBT/ AcOH/ EtOH/ H2O solution. The obtained coatings were subjected to drying at room temperature and were then calcined in the air at different temperatures in a range of 400–600°C in order to obtain clean TiO2 layers. The surface morphology and chemical composition were characterized with the use of a scanning electron microscope (SEM) and an energy dispersive spectrometer (EDX). Research has shown the presence of elements in the TiO2 and the influence of temperatures on layer thickness. Analysis of optical properties and energy gap width of the prepared coatings was determined by means of spectra analysis of absorbance as a function of radiation energy obtained with the use of the UV-VIS spectrophotometer. The obtained spectra of the layers are characterized by a shift of absorption lines towards the visible light wavelengths and the obtained values of band gaps decrease as the calcination temperature rises. The obtained and developed results of TiO2 thin films testify to the wide application possibilities of the layers in elements which use photocatalytic processes such as self-cleaning surfaces, solar cells, pollution removing membranes and optoelectronic components.

20

Effect of Sb and MnO2-Doping on Phase Transitions, Crystal Structure, Thermal, Dielectric, Ferroelectric and Piezoelectric Properties of Na0.5K0.5NbO3 Ceramics

Suchanicz J., Faszczowy I., Czaja P., Kusz J., Zubko M.

Archives of Metallurgy and Materials

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2018

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Vol. 63, iss. 2

633--639

EN

Lead-free ceramics of Na0.5 K0.5 Nb1-x Sbx O3 (NKNS) and Na0.5 K0.5 Nb1-x Sbx O3 + 0.5 mol%MnO2 (NKNS + 0.5 mol%MnO2) (0 < x < 0.06) ceramics were prepared by a conventional solid-state hot pressing method. The ceramics possess a single-phase perovskite structure with orthorhombic symmetry. Microstructural examination revealed that Mn doping of NKNS leads to improvement of densification. The cubic-tetragonal and tetragonal-orthorhombic phase transitions of NKNS shifted to higher and lower temperature, respectively after introduction of Mn ion. Besides, ferroelectric and piezoelectric properties were improved. The results were discussed in term of difference in both ionic size and electronegativity of Nb5+ and Sb5+ and improvement of densification after Mn ion doping.