Wyniki wyszukiwania - BazTech

1

Optimising biosynthesis of antimicrobial copper nanoparticles using aqueous Aegle marmelos leaf extract-based medium

Tarangini Korumilli, Sherlin Shilo Nesa, Jakkala Shanuja, Borah Pallbhika, Wacławek Stanisław, Sabarinath Sankarannair, Rao Korukonda Jagajjanani, Padil Vinod V. T.

Ecological Chemistry and Engineering. S

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2024

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Vol. 31, nr 1

7--17

EN

Copper oxide nanostructures have garnered significant attention in nanotechnology for their diverse applications. This study presents a green synthesis approach using an aqueous Aegle marmelos leaf extract-based medium to produce copper oxide (Cu4O3) nanoparticles. Optimisation was achieved through a simplified Taguchi L9 orthogonal array, investigating critical parameters such as temperature, surfactants (AOT and Tween 80), and additives (ascorbic acid and chitosan). Under optimised conditions (AOT: 0.0012 mM, ascorbic acid: 10 mM, chitosan: 1 %, temperature: 80 °C), near-spherical nanoparticles of ~200 nm were obtained. Comprehensive characterisation through UV-Vis, DLS, electron microscopy, XRD, and FTIR spectroscopy confirmed the nanoparticles’ properties, while antibacterial assays showed promising results against Escherichia coli bacteria.

2

Electrical properties for cold sprayed Nano copper oxide thin films

Muneer Roaa M., Idzikowski Adam, Al-Zubiedy Ali

Production Engineering Archives

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2023

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Vol. 29, Iss. 2

225-230

EN

This work is a Copper oxide (CuO) thin films were effectively produced using cold spray technique. The process take place in an inert gas (helium) without using catalyst. Nano CuO was deposited on a glass slide, using helium as carrier gas heated to 100, 200, 300, and 400oC, respectively on heated glass substrates at 300°C. The effect of structural and electrical properties was examined at each temperature for each film. AFM images show that the CuO thin film have different diameters ranging from 80 to 600 nm, and low surface roughness about 20.9 nm. The measured value of copper oxide resistivity was found to be decrease very much with the increasing temperature. All the result showed that copper oxide is suitable material for photovoltaic applications. This research is part of a larger work for the solar cells industry. Therefore, the aim of this research is to study the electrical properties of solar cells in the primary stages of manufacturing from available materials at low costs.

3

Solar cells based on copper oxide and titanium dioxide prepared by reactive direct-current magnetron sputtering

Wisz Grzegorz, Sawicka-Chudy Paulina, Sibiński Maciej, Starowicz Zbigniew, Płoch Dariusz, Góral A., Bester Mariusz, Cholewa M., Woźny Janusz, Sosna-Głębska A.

Opto-Electronics Review

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2021

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Vol. 29, No. 3

97--104

EN

In this study, solar cells based on copper oxide and titanium dioxide were successfully manufactured using the reactive direct-current magnetron sputtering (DC-MS) technique with similar process parameters. TiO₂/CuO, TiO₂/Cu₂O/CuO/Cu₂O, and TiO₂/Cu₂O solar cells were manufactured via this process. Values of short-circuit current efficiencies, short-circuit current density, open-circuit voltage, and maximum power of PV devices were investigated in the range of 0.02÷0.9%, 75÷350 µA, 75÷350 µA/cm², 16÷550 mV, and 0.6÷27 µW, respectively. The authors compare solar cells reaching the best and the worst conversion efficiency results. Thus, only the two selected solar cells were fully characterized using I-V characteristics, scanning electron microscopy, X-ray diffraction, ellipsometry, Hall effect measurements, and quantum efficiency. The best conversion efficiency of a solar cell presented in this work is about three times higher in comparison with the authors’ previous PV devices.

4

A successful operational initiative in copper oxide flotation: Sequential sulphidisation-flotation technique

Asadi Moharram, Soltani Faraz, Mohammadi Mohammad Reza Tavakoli, Khodadadi Darban Ahmad, Abdollahy Mahmoud

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 2

356--369

EN

One of the main challenges in the copper oxide processing industry is implementation of a flotation method to reduce operating costs. Sulphidising flotation is the most common used technique in which a sulphidisation agent is used to sulphidise the surface of the oxide minerals. In this research, the mentioned technique was used sequentially for the concentration of silicate-carbonate ore containing 3.1% Cu (malachite). The presence of 39% Cu in -38 μm size fraction (fine particles) of feed led to poor grades and recoveries in the initial tests. The addition of sodium sulfide and subsequent flotation at three sequential stages was identified as a successful operational initiative to solve this problem in the following tests. The dosages of 1500, 1567 and 100 g/Mg of sodium silicate, sodium sulfide and potassium amyl xanthate, respectively, the conditioning time of 5 min for sulphidisation and pH=9.72 were chosen as optimum operational conditions using central composite design (CCD) method of experiments design. The rougher concentrate with 9.28% grade and 81.15% recovery was obtained under these conditions. The grade of obtained concentrate was reached to 24% in the cleaner step. The total recovery of both steps was over 74%.

5

Plasma treatment of membrane surfaces using copper oxides

Kowalik-Klimczak Anna, Stanisławek Ewa, Kacprzyńska-Gołacka Joanna, Łożyńska Monika, Bojarska Marta, Piątkiewicz Wojciech, Wieciński Piotr

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

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2019

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no. 1

53--58

EN

The novel technique that will be introduced for modifying surfaces is plasma treatment, which creates a great potential in the development of a variety of functional properties of polymeric membranes. Application of this technique in the processes of membrane modification allows functionalization by the manufacturing metal oxides such as copper oxide, silver oxide, or titanium dioxide on the surface. In this work, the polymeric membranes were activated with low-temperature plasma of different gases (Ar and Ar-O2 ) and subjected to copper oxide deposition. The leaching of copper from the surface of plasmamodified membranes and its permeability and antimicrobial activity were examined. It was found that CuO-modified membranes pre-activated in an Ar or Ar-O2 mixture are characterized by much lower stability than ones without pre-activation. Moreover, the filtration properties of CuO-modified membranes were unchanged compared to native ones, and these filtration materials are characterized by antibacterial properties.

PL

Techniki plazmowe to nowatorskie metody modyfikacji powierzchni, które umożliwiają nadanie różnorodnych właściwości funkcjonalnych membranom polimerowych. Zastosowanie technik plazmowych podczas modyfikacji membran polimerowych umożliwia ich funkcjonalizację poprzez wytwarzanie tlenków metali, takich jak tlenek miedzi, tlenek srebra lub dwutlenek tytanu na ich powierzchniach. W ramach przeprowadzonych prac membrany polimerowe aktywowano niskotemperaturową plazmą w mieszaninie w różnych gazów (Ar i Ar-O2 ), które następnie poddawano modyfikacji przy użyciu tlenku miedzi. Zbadano stabilność związania tlenku miedzi z powierzchnią membran modyfikowanych plazmą i jej przepuszczalność oraz aktywność przeciwdrobnoustrojową. Stwierdzono, że membrany modyfikowane CuO wstępnie aktywowane w Ar lub mieszaninie Ar-O2 charakteryzują się znacznie mniejszą stabilnością niż te bez wstępnej aktywacji. Ponadto właściwości filtracyjne membran modyfikowanych CuO były niezmienione w porównaniu z materiałami natywnymi, a wytworzone materiały filtracyjne charakteryzowały się właściwościami antybakteryjnymi.

6

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.

7

Nanostruktury tlenku miedzi w zastosowaniach fototermicznych

Stępińska Izabela, Czerwosz Elżbieta

Elektronika : konstrukcje, technologie, zastosowania

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2019

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Vol. 60, nr 12

45--49

PL

W pracy przedstawiono wyniki badań strukturalnych wykonanych za pomocą skaningowej i transmisyjnej mikroskopii elektronowej, dyfrakcji rentgenowskiej oraz spektroskopii w podczerwieni tlenku miedzi w postaci nanodrutów otrzymanych w procesie termicznego utleniania. Ponadto przeprowadzono eksperymenty oddziaływania promieniowania elektromagnetycznego z nanodrutami CuO.

EN

In this work the results of structural studies, performed by scanning electron microscopy and transmission electron microscopy, X-ray diffraction and infrared spectroscopy of copper oxide in nanorods form obtained in thermal oxidation, were presented. Moreover, interaction between CuO nanorods and electromagnetic radiation was investigated.

8

Analiza efektu przełączania rezystancji w strukturach cienkowarstwowych z różnym profilem składu materiałowego

Kotwica Tomasz, Domaradzki Jarosław, Kaczmarek Danuta, Rogala Jacek, Strzyżewski Maciej

Elektronika : konstrukcje, technologie, zastosowania

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2019

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Vol. 60, nr 7

14--17

PL

Niniejsza praca przedstawia wyniki badań elektrycznych oraz strukturalnych cienkich warstw (Ti-Cu)Ox wytworzonych metodą rozpylania magnetronowego z zaprogramowanym profilem rozkładu pierwiastków. Wytworzenie cienkich warstw zaplanowano tak, aby uzyskać gradientową zmianę koncentracji miedzi w funkcji grubości osadzonej warstwy o zadanym kształcie. Analiza składu materiałowego wykazała, że wytworzone warstwy posiadały podobny skład materiałowy wynoszący odpowiednio (Ti52Cu48)Ox oraz (Ti48Cu52)Ox oraz posiadały zadany kształt profilu rozkładu miedzi. Przeprowadzone analizy przekroi struktur wykonane za pomocą transmisyjnego mikroskopu elektronowego potwierdziły uzyskanie zarówno gradientu rozkładu miedzi o kształcie litery V, jak i gradientu rozkładu miedzi o kształcie litery U w całej objętości cienkiej warstwy. Badania elektryczne wykazały, że mimo podobnego składu materiałowego wytworzonych cienkich warstw, uzyskano różne przebiegi charakterystyk prądowo-napięciowych, a więc możliwe jest sterowanie typem efektu przełączania rezystancji przez zadanie określonego profilu rozkładu pierwiastków w danej strukturze.

EN

The present paper shows the results of electrical properties along with the investigations of the structure of the (Ti-Cu)Ox thin films layers fabricated by the magnetron sputtering. Thin films were prepared in order to achieve gradient change of the cooper concentration in the function of the thickness of the deposited layers with programmed shape of elemental profiles. Analysis of the material compositions showed, that deposited films have similar material composition respectively, (Ti52Cu48)Ox and (Ti48Cu52)Ox with programmed specific shape of the elements gradient profile. Conducted analysis of the films with the help of transmission electron microscope proved the V-shape and the U-shape gradient distribution of the cooper across the thin films. Electrical measurements have shown that despite similar material composition of the fabricated thin films, different waveforms of current-voltage characteristics were obtained, leading to the statement that it is possible to control the type of mechanism of the resistive switching effect by programming a specific distribution profile of elements in a given structure.

9

Symulacja numeryczna ogniw heterozłączowych TiO2/Cu2O(CuO), przy pomocy programu SCAPS

Sawicka-Chudy P., Sibiński M., Cholewa M., Sosna-Głębska A., Wisz G.

Przegląd Elektrotechniczny

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2018

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R. 94, nr 8

17--20

PL

W artykule przedstawiono wyniki symulacji numerycznej modeli cienkowarstwowych struktur fotowoltaicznych w programie SCAPS. Obliczono podstawowe parametry elektryczne (Jsc, η, VMPP, JMPP) dla standardowych warunków testowych STC (AM1.5G, 100 mW/cm2, 300K) oraz zbadano wpływ warstwy absorbera (Cu2O, CuO) i warstwy buforowej (TiO2) na działanie ogniw słonecznych. Następnie porównano charakterystyki pojemnościowo-napięciowe, Mott Schottky’iego oraz wpływ defektów dla ogniw TiO2/Cu2O oraz TiO2/CuO.

EN

In the presented work, the Cu2O/TiO2 and CuO/TiO2 heterojunction solar cells have been analyzed by the help of Solar Cell Capacitance Simulator (SCAPS). The effect of absorber and buffer layers on the cell photoconversion efficiency, short circuit current density and open circuit voltage were simulated without defects. Next, capacitance-voltage, Mott–Schottky characteristic were calculated and analized. Finally, authors examined the effects of defect density on the efficiency.

10

Fabrication and characterization of Zn doped CuO nanofiber using newly designed nanofiber generator for the photodegradation of methylene blue from textile effluent

Sethuraman R. G., Venkatachalam T., Kirupha S. D.

Materials Science Poland

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2018

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Vol. 36, No. 3

520--529

EN

High aspect ratio, Zn doped copper oxide (Zn-CuO) nanofibers have been fabricated employing a newly designed electrospun coating unit using copper acetate, sodium hydroxide and polyethylene glycol in aqueous state. The prepared Zn doped copper oxide (Zn-CuO) nanofibers were sintered at 400 °C, 500 °C and 600 °C separately and characterized using X-ray diffraction XRD, Fourier transformation infrared spectroscopy FT-IR, scanning electron microscopy SEM, energy dispersive spectroscopy EDS. The average crystallite size was in the range of 28 nm to 30 nm. Optical properties of Zn-CuO nanofibers were analyzed using UV-DRS studies which showed a blue shift in the absorption band. An increase in band gap with the increase in postannealing temperature was observed due to the blue shift in absorption edge of CuO causing enhanced photodegradation. The catalytic properties of the CuO nanofibers were tested using methylene blue in aqueous medium. The influences of parameters responsible for high photodegradation were optimized and the rate of the photodegradation process was calculated using photodegradation kinetics. The reusability test was conducted to find the stability of the fabricated Zn-CuO nanofibers.

11

Characterization of CuO/n-Si heterojunction solar cells produced by thermal evaporation

Özmenteş R., Temirci C., Özkartal A., Ejderha K., Yildirim N.

Materials Science Poland

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2018

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Vol. 36, No. 4

668--674

EN

Copper(II) oxide (CuO) in powder form was evaporated thermally on the front surface of an n-Si (1 0 0) single crystal using a vacuum coating unit. Structural investigation of the deposited CuO film was made using X-ray difraction (XRD) and energy dispersive X-ray analysis (EDX) techniques. It was determined from the obtained results that the copper oxide films exhibited single-phase CuO properties in a monoclinic crystal structure. Transmittance measurement of the CuO film was performed by a UV-Vis spectrophotometer. Band gap energy of the film was determined as 1.74 eV under indirect band gap assumption. Current-voltage (I-V) measurements of the CuO/n-Si heterojunctions were performed under illumination and in the dark to reveal the photovoltaic and electrical properties of the produced samples. From the I-V measurements, it was revealed that the CuO/n-Si heterojunctions produced by thermal evaporation exibit excellent rectifying properties in dark and photovoltaic properties under illumination. Conversion efficiencies of the CuO/n-Si solar cells are comparable to those of CuO/n-Si produced by other methods described in the literature.

12

The polyamide membranes modified by copper oxide using PVD techniques

Kowalik-Klimczak A., Stanisławek E., Kacprzyńska-Gołacka J., Kaźmierczak B., Wieciński P.

Journal of Machine Construction and Maintenance - Problemy Eksploatacji

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2018

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no. 3

49--55

EN

The aim of this research was to examine the influence of process parameters of low-temperature plasma treatment on the permeability, stability, and antibacterial properties of polyamide membranes. As a result of the work, the process conditions were selected for plasma deposition of copper oxide, which enable the high stability of the copper oxide coatings on the filtration materials characterized by efficient permeability and antimicrobial activity. Further work is necessary to examine new generation filtration materials in real process conditions for industrial post-consumer liquids. This can contribute to the implementation of the new generation filtration materials proposed in this work.

PL

W pracy przedstawiono wyniki badań dotyczące wpływu parametrów procesowych niskotemperaturowej plazmowej obróbki powierzchni membran poliamidowych na przepuszczalność, stabilność i właściwości antybakteryjne wytworzonych materiałów filtracyjnych. W rezultacie przeprowadzonych eksperymentów dobrano warunki procesowe plazmowej obróbki tlenkiem miedzi, które umożliwiają wytworzenie stabilnych materiałów filtracyjnych charakteryzujących się wysoką przepuszczalnością i właściwościami antybakteryjnymi. Konieczne są dalsze prace umożliwiające zbadanie zachowania wytworzonych materiałów filtracyjnych w rzeczywistych warunkach procesowych przy użyciu ścieków przemysłowych. Dopiero takie działania mogą przyczynić się do udanej komercjalizacji rozwiązania materiałowego zaproponowanego w niniejszej pracy.

13

Evaluation of the quality of titanium oxide and copper oxide layers by means of optical microscopy

Głuszek A., Sawicka-Chudy P., Wisz G., Sibiński M., Cholewa M.

Energy Policy Studies

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2018

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No. 1 (2)

39--51

EN

The aim of this paper is to analyse high-resolution optical images of the surface layers of titanium oxide and copper oxide. The materials were produced using the PREVAC Modular Platform for layer deposition located at the University of Rzeszów. Images with a magnification of 50x were obtained using an optical microscope. On the basis of the results obtained, the quality of the layers was evaluated based on the image analysis. The quantitative method of analysis was applied, as a result of which the conditions of the manufacturing process for which the obtained layers had the highest homogeneity were indicated. The minimum range of grey shade counting was from 65 to 150 and the maximum range from 135 to 220. The standard deviation was from 8 to 40%.

14

Analysis of chemical and phase composition of copper oxide prepared by direct current sputtering for photovoltaic applications

Sawicka-Chudy P., Wielgosz M., Wal A., Cieniek B., Wisz G., Głowa Ł., Cholewa M., Sawicka J.

Energy Policy Studies

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2018

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No. 1 (2)

3--11

EN

This paper presents the application of X-ray fluorescence and X-ray diffraction methods for the study of copper oxide structures as an absorber layer in thin-film solar cells. The layers of copper oxide were applied by direct current magnetron sputtering. Quantitative and qualitative analysis of oxide layers were performed using XRF (X-ray fluorescence). The studies showed a high copper content in both samples, amounting to 98% and 96%, as well as trace amounts of other elements (nickel, lead). The XRD (X-ray diffraction) study showed Cu20 and Cu8O phases, amorphism ranging from 24% to 44%, and crystallinity from 55% to 75%. Crystallites of 30 nm were also determined. The aim of the study was to determine the chemical and phase composition of the layers obtained and to determine the degree of their contamination depending on the parameters of the manufacturing technology in terms of their application in photovoltaics. One of the samples showed an advantage both in terms of material and structural composition.

15

Investigation of Metal Oxides as Catalysts for the Thermal Decomposition of Potassium Chlorate(VII)

Wojewódka A., Zakusylo R., Kravets V., Romanchenko A., Jarosz T.

Central European Journal of Energetic Materials

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2018

|

Vol. 15, no. 2

327--338

EN

The results of studies on the thermal decomposition of potassium chlorate(VII) (PP) and the catalytic effects of copper, iron, nickel, titanium, magnesium, chromium and manganese oxides on the process are presented in this paper. The investigated oxides are ranked according to the magnitude of their catalytic effect; of these, CuO and МnО2 show the best catalytic performance. These oxides reduce the PP decomposition temperature from 919.3 K down to even 825.2 K. The share of the catalytic additive in the composition, required to achieve a desirable thermal decomposition profile, was found to be no more than 0.5 wt.%. The activation energy of the decomposition process was determined, using the modified Freeman and Carroll method for both neat PP and PP supplemented with MnO2; the addition of the catalyst produced a 48.8% decrease in the activation energy of thermal decomposition.

16

Fabrication of dye sensitized solar cell using chemically tuned CuO nanoparticles prepared by sol-gel method

Prabhin V. S., Jeyasubramanian K., Romulus N. R., Singh N. N.

Archives of Materials Science and Engineering

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2017

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Vol. 83, nr 1

5--9

EN

This work details about the isolation of CuO nanoflakes by a simple precipitation technique. Further it is coated over ITO substrate using spin coating technique. DSS cell capabilities were checked by placing a drop of plant dye derived from pomegranate. Design/methodology/approach: CuO nano flakes, a novel Nano sized metal oxide have been synthesized by sol-gel method. The synthesised flakes were characterized by using XRD (X-ray diffraction), FESEM, UV-VIS and PL measurements techniques. XRD studies show that, the copper oxide formed has monoclinic structure. Findings: The grain size of the synthesized copper oxide nanoflakes were measured from FESEM and found that the size was around 200 nm. The UV-VIS measurement show that the band gap of CuO nanoflakes were found to be 3.03 eV, which is in the range of a good semiconductor. Finally, the dye sensitized solar cell was fabricated and its power conversion efficiency η (PCE) was determined. Practical implications: The search for green sources or generators of energy is considered as one of the priorities in today's society and occupies many policy maker’s agenda. It is believed that nanocrystalline photovoltaic devices are becoming viable contender for large scale future solar energy converters.

17

Próba zwiększenia własności przeciwzatarciowych Smaru Maszynowego 2

Czupryk W.

Tribologia

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2012

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nr 3

35-44

PL

Smar Maszynowy 2 charakteryzuje się zbyt niskimi własnościami przeciwzatarciowymi w zastosowaniu do smarowania łożysk tocznych. Cechę tę potwierdzają dane literaturowe i wyniki badań własnych wykonanych na aparacie czterokulowym. W celu zwiększenia własności przeciwzatarciowych Smaru Maszynowego 2 wprowadzono do jego objętości mieszankę tlenku miedzi i gliceryny z alkoholem etylowym. Badania miały na celu dać odpowiedź na pytanie, czy w warunkach dużych nacisków, zmiennych naprężeń i wysokich krótkotrwałych temperatur w obszarze kontaktu tlenek miedzi będzie redukowany do miedzi metalicznej, która będzie spełniała rolę smaru stałego. Badania wykonano na aparacie czterokulowym w trzech następujących po sobie seriach. Każda z nich trwała 60 sekund. Nacisk był stały i wynosił 1472 N. Po wykonaniu badań obliczono graniczne obciążenie zatarcia G0Z. Stwierdzono znaczny wzrost wskaźnika G0Z dla smarów z wymienionymi wcześniej dodatkami: G0Z dla Smaru Maszynowego 2 wynosił 529 [N/mm2], a dla innych składów dodatków wprowadzonych do smaru zawierał się w przedziale 900–1736 [N/mm2]. W celu potwierdzenia zjawiska redukcji tlenku miedzi do miedzi metalicznej wykonano badania powierzchniowe i wgłębne z użyciem spektrometrii AES. Wyniki analiz potwierdziły występowanie w warstwie powierzchniowej i warstwach głębiej zlokalizowanych miedzi metalicznej. Obecność warstewki metalicznej miedzi na ścieżce kontaktu spełniającej rolę smaru stałego skutkowała zwiększeniem odporności na zatarcie Ft trzy-, a nawet czterokrotnie w stosunku do tego samego wskaźnika dla Smaru Maszynowego 2.

EN

The anti-seizing properties of Machine Grease 2 are too poor to ensure the proper lubrication of rolling bearings. This is confirmed by research publications and the results of the author's tests carried out using the four-ball EP tester. In order to enhance the anti-seizing properties of Machine Grease 2, a mixture of copper oxide, glycerine, and ethyl alcohol was introduced into its volume. The aim of the tests was to find out if, under high pressures, variable stresses and short-duration temperatures in the contact region cause the copper oxide to be reduced to metallic copper functioning as grease. The tests in the four-ball EP tester were carried out in three consecutive series, each lasting 60 seconds. The pressure remained constant and amounted to 1472 N. After the tests, the limit of the seizure load G0Z was calculated. Index G0Z was found to be considerably higher for lubricants containing the above additives, amounting to 529 [N/mm2] and 900–1736 [N/mm2] for Machine Grease 2 and lubricating compositions containing the mixture of copper oxide, glycerine and ethyl alcohol, respectively. Due to the presence a metallic copper film on the contact path, seizure resistance Pt increased three to even four times in comparison with this index for Machine Grease 2.

18

Symulacja komputerowa procesu redukcji ciekłego żużla

Kalisz D., Rzadkosz S., Piękoś M.

Archives of Foundry Engineering

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2012

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Vol. 12, iss. 1s

91--96

PL

Praca zajmuje się termodynamiczną analizą elementarnych procesów chemicznych zachodzących podczas redukcji żużla zawierającego tlenek miedzi. Redukcja żużla zachodzi przez zastosowanie reduktora w postaci stałej - węgla, gazowej - tlenek węgla lub węgla rozpuszczonego w ciekłym żużlu. Obecna praca rozpatruje dwa procesy chemiczne: reakcję ciekłego żużla z węglem oraz z tlenkiem węgla. Korzystając z komercyjnego oprogramowania FATSage obliczono w warunkach równowagi termodynamicznej składy faz dla układów: stały węgiel – ciekły żużel - stop Cu–Fe–Pb – faza gzowa oraz gazowy CO – ciekły żużel – stop Cu–Fe–Pb – faza gazowa. Symulację prowadzono dla temperatury procesu 1500, 1600, 1700 K. Gazowe produkty reakcji redukcji i stop Cu–Fe–Pb były usuwane z układu w każdym kroku obliczeniowym. Uzyskane wyniki obliczeń wykazały, że redukcja za pomocą węgla odgrywa zasadniczą rolę w procesie odzysku miedzi.

EN

The present work deals with thermodynamic analysis of process of the reduction of molten slag containing copper oxide. Reduction of liquid slag is possible with solid carbon, gaseous carbon oxide. and carbon dissolved in liquid slag. This work studied two chemical reactions of liquid slag containing copper oxide: with solid carbon and gaseous CO. Thermodynamic equilibrium in the system: solid carbon – liquid slag – metallic alloy Cu–Fe–Pb – gas and gaseous CO – liquid slag – metallic Cu–Fe–Pb – gas were calculated by means of FACTSage software. The simulation of the progress of reduction process at 1500, 1600, 1700K was obtained under assumption that the gaseous reduction products and metallic alloy Cu–Fe–Pb were removed from consideration after each simulation step. The calculation revealed that consumption of reducing agent is much higher in the case of CO reduction. The effect of simulation suggested, that reduction with solid carbon is the predominant mode of industrial process.

19

Photocatalytic Degradation of Crystal Violet by Use of Copper Oxide as Semiconductor

Shah A., Mittal N., Bhati I., Sharma V. K., Punjabi P. B.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 11

2001-2007

EN

The photocatalytic degradation of crystal violet on copper oxidesemi conductor suspended in aqueous solution has been carried out. The progress of reaction has been studied spectrophotometrically by observing absorbance of reaction mixture at different time intervals. The effects of various parameters such as concentration of crystal violet, pH of reaction mixture amount of semiconductor and intensity of light on the rate of reaction have also been observed. The photocatalytic degradation of crystal violet follows pseudo first order kinetics and the rate constant has been determined. Atentative mecha nism for the reaction has also been proposed.

20

Oxidation of Thiophene over Copper and Manganesem Based Oxides Modified with Pt and Pd

Szynkowska M. I., Węglińska A., Kowalczyk Ł., Paryjczak T.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 6

1163-1172

EN

Copper and manganese-based catalysts (5 per cent Cu/Al2O3, 5 per cent Mn/Al2O3) modified with different amount of Pt or Pd (0.2 or 1 wt. per cent) have been studied in oxidation of thiophene. The activity experiments reveal that samples containing Cu display higher activity for thiophene oxidation in relation to manganese-based catalysts. It is shown that lower activity of Mn catalyst is accompanied by pronounced non-homogenous distribution of Mn phase on the catalyst surface and lower reducibility. Further more, catalytic and reduction be haviour of monometallic catalysts is in fluenced by the presence of small amounts of Pt or Pd, suggesting synergism of the components of bimetallic catalysts.