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Content available Kolej Transandyjska w Peru
PL
Zbudowana pod koniec XIX w. Kolej Transandyjska w Peru powstała z udziałem kapitału zagranicznego oraz obcej myśli technicznej. Motywem budowy linii kolejowej był zamiar eksploatacji bogatych złóż miedzi, a także srebra i złota. Zastosowane rozwiązania techniczne nawet dzisiaj budzą podziw, w szczególności tzw. nawroty (zygzaki), które pozwoliły poprowadzić linię kolejową po niedostępnych terenach górskich pasma Andów, jak to określił główny inwestor, Henry Meiggs, amerykański przedsiębiorca: tam gdzie dojdzie lama, może dojechać pociąg. Głównym inżynierem, który zaprojektował linię kolejową oraz nadzorował wykonawstwo, był Ernest Malinowski, polski specjalista, zasłużony dla Peru podczas wojny z Hiszpanią w 1866 r., ogłoszony przez mieszkańców tego kraju bohaterem narodowym.
EN
Trans-Andean Railway built at the end of the 19th century in Peru, was created with the participation of foreign capital and technical knowledge. The motive for construction of the railway line was the intention to exploit rich copper deposits and silver and gold. The applied technical solutions are admirable even today, particularly the so-called zigzags that allowed to lead the railway line through inaccessible mountain areas of the Andes, as the principal investor, Henry Meiggs, an US entrepreneur said: a train can go, where the llama goes. Ernest Malinowski, a Polish specialist, was the chief engineer who designed the railway line and supervised. Malinowski was also engaged in the war with Spain in 1866. Finally, the inhabitants of Peru proclaimed him as the national hero.
EN
Copper is one of the main components of friction materials used in vehicles’ brake systems. It is mainly used due to two features: good thermal conductivity and lubricity. Unfortunately, it is harmful no only to humans but also more to aquatic life. For this reason, there is an attempt to minimize its use. This paper presents the results of testing four groups of samples with different Cu contents (5, 10, 15, and 20%). Laboratory tests were performed using calorimetry, hot wire method, and pin-on-disc method. This allowed to determine selected physico-chemical material properties of samples, which were then used for simulation studies. They were intended to check how the heating process of friction materials with a chemical composition such as made samples will proceed in real conditions, in real brake pads.
EN
This paper addresses the issue of plasma treatment of the surface of polypropylene (PP) using sputtering of silver (Ag) and copper (Cu) and their oxides with MS-PVD in order to impart antimicrobial activity. It was found that plasma treatment of PP with Cu and Ag based layers allows to provide excellent antimicrobial properties due to a constant release of metal ions. The samples of PP treated with Cu and CuO were characterized by highest antimicrobial properties and stability of the coatings. The most stable and least effective coating against bacteria was Ag-PP sample. In turn, AgO-PP was characterized by the lowest stability in aqueous conditions and strong antimicrobial activity. It was found that leaching of metal ions from the surface of treated PP even in exceptional levels plays a crucial role in bactericidal activity.
PL
Niniejsza praca dotyczy plazmowej obróbki powierzchni polipropylenu (PP) przy użyciu miedzi (Cu) i srebra (Ag) oraz ich tlenków. Powłoki Cu, CuO, Agi AgO, wytworzone na powierzchni PP metodą rozpylania magnetronowego MS-PVD, zbadano pod względem morfologii, składu, stabilności i właściwości antybakteryjnych. Materiały powierzchniowo zmodyfikowane przy użyciu Cu i CuO charakteryzowały się najsilniejszymi właściwościami przeciwbakteryjnymi i najmniejszą stabilnością i trwałością w środowisku wodnym. Powłoka AgO wykazywała najmniejszą stabilność w warunkach wodnych i silną aktywność przeciwbakteryjną, natomiast powłoka Ag wykazywała największą stabilność, a zarazem najsłabsze działanie przeciwbakteryjne. Uzyskane wyniki wskazują, że uwalniane z naniesionych powłok jony, nawet w niewielkim stężeniu, wykazują silne działanie antybakteryjne.
EN
Copper oxide ore was pre-concentrated using near infrared sensor-based method and classified as product, middling and waste. The product and middling fractions were leached with ammonium chloride reagent. The effect of temperature, ammonium chloride concentration, solid- liquid ratio, stirring speed and particle size experimental variables were investigated. Mineralogical and chemical analysis of the ore fractions indicated that copper content was in accordance with the preconcentration strategy, with the product having a higher concentration than the middling and waste. The rate of copper extraction was found to be higher in the product than in the middling sample which further supports the near infrared classification, QEMSCAN®, X-ray diffraction, SEM mineralogical and X-ray florescence and Inductively coupled plasma Mass spectrometry chemical data. It was revealed that the leaching rate increases with increasing ammonium chloride concentration, temperature and decreasing ore particle size, stirring speed and solid-liquid ratio. Analysis of the experimental data by shrinking core model indicated that the dissolution kinetics follow the heterogeneous reaction model for the chemical control mechanism where the activation energies of 45.9 kJ/mol and 47.5 kJ/mol for product and middling fractions respectively were obtained. Characterization of the residue obtained at optimum leaching condition with X-ray diffraction suggests that copper was selectively leached when compared to the profile of the raw ore. The trace levels of metals associated with abundant X-ray diffraction profiles of residue found in the leachate further confirm the selective leaching process.
EN
Raman spectroscopy as a high-resolution characterization technique was used to analyze various pure metal sulfides immersed in water, namely pyrite (FeS2), chalcopyrite (CuFeS2), sphalerite (ZnS), marmatite (Zn1-XFeXS) and galena (PbS). The Raman characterization was undertaken in situ with the minerals immersed in water. Characteristic Raman spectrum that shows the vibrational modes of the atomic bonds in the mineral crystal structure is reported. This spectroscopic technique revealed that marmatite particles are composed of micro-size, perhaps nano-size, zones with different Fe and Zn content. With the intensity of the Fe-S and Zn-S Raman signals, the iron content of the zones was quantified. The copper ion up-take by marmatite particles was studied through this technique. It was found that the up-take of copper ions on the marmatite zones depended on their Fe content. Copper ion up-take occurred more preferentially on the zones of low Fe content than on those of high Fe content. The adsorption of the collector propyl xanthate on pyrite and chalcopyrite was also assessed by Raman spectroscopy. The Raman spectrum revealed that dixanthogen formed on the surface of these sulfides.
EN
The effect of air rate and froth depth on the entrainment factor in flotation has been extensively studied, but further investigation on the underlying mechanism for their effect is still required. In this study, flotation tests were performed at different air rates and froth depths in a 3 dm3 continuously operated cell using an artificial copper ore. The results showed that entrainment factor was affected by both air rate and froth depth, and the combined effect of these variables on entrainment factor depended strongly on the particle size. The entrainment factor increased with either increasing air rate at a relatively shallow froth or decreasing froth depth at a relatively high air rate. At a very low air rate and deep froth, higher entrainment factor was observed for mid-size and coarse particles. When the entrainment factor was correlated to the effective liquid velocity at the pulp/froth interface, the results indicated that multiple mechanisms were responsible for the effect on entrainment factor. At a relatively high air rate and shallow froth depth, entrainment factor had a linear relationship with the interface effective liquid velocity, suggesting that drag force dominated the change in the entrainment factor when air rate and froth depth were varied. At a very low air rate and deep froth, the entrainment factor for fine particles was found to correlate strongly with the interface effective liquid velocity, while the entrapment of solid particles may be the main reason for the high entrainment factor for mid-size and coarse particles under this condition.
EN
The aim of the study was to evaluate the application of bioleaching technique to reduce content of selected heavy metals (Zn, Cu) in sewage sludge, and hence to indicate possibilities for metals recovery from this type of waste. Bioleaching experiments were carried out with mixed bacteria Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, using leaching media: ferrous sulfate with different concentrations of Fe2+ (2 g/dm3 and 9 g/dm3) and sulfuric acid (VI). Dynamics of the increase in zinc concentration in biological systems was almost identical for both 9 g Fe2+/dm3 and 2 g Fe2+/dm3 in samples. However, higher values of Cu concentration were achieved using a medium with iron(II) salt 9 g/dm3 than in a 2 g/dm3 solution. Bioleaching with 9 g Fe2+/dm3 allowed for a nearly 20-fold reduction of zinc content and a 2-fold reduction in copper content in sewage sludge. Using 9 g/dm3 ferrous sulfate bioleaching could dissolve 94.8% Zn and 58.9%, whereas chemical leaching dissolved 47.3% Zn and 4.2% Cu.
EN
In this work, the analytical expressions describing experimental data of silver, gold, copper and aluminum dielectric permittivity in a wide spectral range are presented. A comparison of samples production techniques, the measurement methods and the experimental data of different authors led to the conclusion that the most valid data are given by MCPEAK et al. (ACS Photonics 2(3),2015, pp. 326–333) and BABAR et al. (Appl. Opt. 54(3), 2015, pp. 477–481), which are close to each other. Thus, the analytical expressions for silver, gold, copper and aluminum dielectric permittivity spectral dependences are based on it. The spectral range in which the dielectric permittivity is represented by the corresponding analytical expression is divided into several intervals.There is a specific function for each wave length range.
PL
Niniejszy artykuł dotyczy oceny stabilności oksydacyjnej paliwa do silników z zapłonem samoczynnym B7 (oleju napędowego z zawartością FAME do 7%) z dodatkami antyutleniającymi w dynamicznym kontakcie z miedzią metaliczną. Paliwo B7 może być stosowane w każdym silniku wysokoprężnym bez dodatkowych modyfikacji. Jest ono mniej uciążliwe dla środowiska naturalnego niż czysty olej napędowy z ropy naftowej, ponieważ w części pochodzi ze źródeł odnawialnych. Jedyną wadą paliw z zawartością bioestrów i biodiesli jest to, że są one podatne na utlenianie, które może wywołać polimeryzację bioestru, tworząc nierozpuszczalne osady, blokujące filtry paliwowe. Kwaśne produkty reakcji utleniania bioestrów mogą powodować korozję układu napędowego. Stabilność oksydacyjna jest podstawową właściwością eksploatacyjną oznaczaną obecnie dla paliw do silników wysokoprężnych z zapłonem samoczynnym. Zbyt niska stabilność oksydacyjna paliwa stanowi główną przyczynę niespełnienia wymagań normy PN-EN 590 + A1:2017-06. Europejska norma dotycząca paliw do silników z zapłonem samoczynnym PN-EN 590 + A1:2017-06 wymaga określenia stabilności oksydacyjnej w 110°C metodą Rancimat (PN-EN 15751). Minimalny czas indukcji to 20 godzin. W artykule przedstawiono stanowisko badawcze do oceny skuteczności działania dodatków antyoksydacyjnych w paliwach poddanych działaniu miedzi. Dynamiczny kontakt paliwa do silników o zapłonie samoczynnym zawierającego bioestry z metaliczną miedzią wielokrotnie przyspiesza proces utleniania, potwierdzając fakt, że ma ona katalityczny wpływ na stabilność oksydacyjną tego paliwa. Przedstawiono wyniki badań wpływu miedzi na stabilność oksydacyjną paliw z zawartością FAME powyżej 2% z różnymi dodatkami antyutleniającymi. Wykazano zależność stabilności oksydacyjnej paliwa od rodzaju zastosowanego dodatku zapobiegającego zbyt szybkiemu utlenianiu, jego stężenia i czasu dynamicznego kontaktu z miedzią metaliczną. Podobną zależność wykazano dla deaktywatorów metali dodawanych do paliw do silników z zapłonem samoczynnym.
EN
This article concerns assessing the oxidative stability of diesel fuel with FAME and antioxidant additives in dynamic contact with metallic copper. Biodiesel fuel is considered as a better fuel from the environmental point of view compared to petroleum diesel because it is renewable, non-toxic in nature and essentially free of sulphur and aromatics and can be used in any diesel engine without modification. One drawback of biodiesel is that it is susceptible to oxidation which can induce polymerization of esters and can form insoluble gums and sediments which are known to cause fuel filter plugging. Oxidative stability is the basic operational property currently determined for compression-ignition diesel fuels. Excessively low oxidative stability of the fuel is the main reason for not meeting the requirements of PN-EN 590 + A1:2017-06. The European diesel standard EN 590 calls for determining oxidation stability at 110C with a minimum induction time of 20 h according to the Rancimat method (PN-EN 15751). The article presents the research station for assessing the effectiveness of antioxidant additives in fuels treated with copper. The study examined the effect of copper on the oxidative stability of biofuels with various antioxidant additives. The results of the influence of copper on the oxidative stability of biofuels with various antioxidant additives are presented. The dynamic contact of fuel containing bioesters with copper repeatedly accelerates the oxidation process confirming the fact that it has a catalytic effect on oxidative stability. The results of studies on the influence of copper on the oxidative stability of fuels with FAME content above 2% with various antioxidant additives are presented. The relationship between oxidative stability and the type of additive used to prevent excessively rapid oxidation, its concentration and the time of dynamic contact with fuel have been demonstrated. A similar relationship was demonstrated for metal deactivators added to diesel fuel.
EN
Cu-doped TiO2 having a brookite phase and showing enhanced visible light photocatalytic activity was synthesized using a mild solvothermal method. The as-prepared samples were characterized by various techniques, such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis diffuse reflectance spectroscopy. Photocatalytic activity of Cu-doped brookite TiO2 nanoparticles was evaluated by photodegradation of methylene blue under visible light irradiation. The X-ray diffraction analysis showed that the crystallite size of Cu-doped brookite TiO2 samples decreased with the increase of Cu concentration in the samples. The UV-Vis diffuse reflectance spectroscopy analysis of the Cu-doped TiO2 samples showed a shift to lower energy levels in the band gap compared with that of bare phase brookite TiO2. Cu doped brookite TiO2 can obviously improve its visible light photocatalytic activity because of Cu ions acting as electron acceptors and inhibiting electron-hole recombination. The brookite TiO2 sample with 7.0 wt.% Cu showed the highest photocatalytic activity and the corresponding degradation rate of MB (10 mg/L) reached to 87 % after visible light illumination for 120 min, much higher than that of bare brookite TiO2 prepared under the same conditions (78 %).
EN
In this paper, the sorption capacity of Norit SX2 activated carbon, ground rice husks and C‑160 ion exchange resin in relation to the Cu2+ and Co2+ ions was compared. The studied sorption processes were described using the Langmuir adsorption model. The C‑160 ion exchange resin was characterized by the highest affinity for both Cu2+ and Co2+ ions. It was shown that rice husk and active carbon are efficient sorbents in diluted solutions. The copper recovery for activated carbon, ion exchanger and rice husk was high. The efficiency of this process was 98.1%; 92.3% and 88.9%, respectively. Reducing the volume of acid used for regeneration allowed the solution to be concentrated and facilitated element recovery. Regeneration for cobalt occurred to a lesser extent.
EN
In the paper, the assessment of the impact of heavy metals on water objects, namely copper and chromium was performed, and the methods for their neutralization were defined. A scientifically grounded method for the selection of natural zeolite for the purification of wastewater from heavy metals has been developed, provided that they are jointly present. The physicochemical characteristics of two metals related to heavy metals are presented: copper and chromium. The methods for determining the sorption capacity of natural zeolite for copper and chromium compounds, as well as the methods of analytical control of the wastewater components were presented. The results of the experimental studies on the combined adsorption of copper and chromium cations by natural zeolite under static conditions were presented. The changes in the chemical composition of the zeolite surface as a result of heavy metal sorption have been investigated. The influence of the nature of the ions and the pH of the adsorption medium on the selectivity of the heavy metal ions extraction by zeolite was analyzed. A diagram of the composition of the solution, depending on the pH values, was constructed. The pH of the beginning of deposition of the corresponding heavy metal hydroxides on the zeolite surface was calculated. While analyzing the results of experimental studies on the combined adsorption of copper and chromium ions, it was found that the copper ions are significantly better adsorbed by the sorbent than the chromium ions. Despite the same concentration of the chromium and copper ions in solution, Cu2+ is extracted selectively. As can be seen from the results of experimental studies, the concentration of copper on the surface of the sorbent increases from 0.628% mass at a concentration of 0.01 g/dm3 to 47.380% mass at a concentration of 1 g/dm3. The studies on the static activity of clinoptilolite for the copper and chromium ions indicate a simultaneous mechanism of the process, which involves ion exchange and physical adsorption. The concentration of the chromium ions on the surface of the sorbent after adsorption depends on the increase of the concentration of Cr3+ in the original solution to a lesser extent. The results of the studies on the combined adsorption of the Cu2+ and Cr3+ ions indicate the possibility of their chromatographic separation, which makes their further use possible.
EN
This paper examines the process and methodological aspects of implementing online X-ray fluorescence monitoring of ore in terms of its silver, cadmium, zinc, lead, molybdenum, and iron grade at the process conveyors at Balkhash and Karagaily Concentrators and the main conveyor of the Nurkazgan underground mine operated by Kazakhmys Corporation LLC. The research was complicated by the need to: a) ensure reliable measurement of silver and cadmium in the range of 1+ ppm, molybdenum in the range of 10+ ppm, as well as copper, zinc, lead, and iron in the ore size class –300 mm; b) implement monitoring of the grade of these elements (except molybdenum) at Balkhash Concentrator in the waste slag of Balkhash Copper Smelter, characterized by a very complex elemental matrix. A modification of the ore monitoring station RLP-21T (by Aspap Geo LLC, Alma-Ata) was developed, implemented, and thoroughly tested for online monitoring of low-grade silver ore flows. Energy dispersive X-ray fluorescence method was adopted for ore assays. Instrument spectra were measured every second. Silver, cadmium, and molybdenum grade was calculated based on 40 measurements, copper, zinc, lead, and iron grade – based on 20 measurements.
PL
W artykule przeanalizowano proces i aspekty metodologiczne wdrażania zdalnego monitorowania zawartości srebra, kadmu, cynku, ołowiu, molibdenu i żelaza w zakładach wzbogacania Balkhash i Karagaily oraz na głównym przenośniku w kopalni podziemnej Nurkazgan obsługiwana przez Kazakhmys Corporation LLC. Badania były skomplikowane ze względu na konieczność: a) zapewnienia niezawodnego pomiaru srebra i kadmu w zakresie 1+ ppm, molibdenu w zakresie 10+ ppm, a także miedzi, cynku, ołowiu i żelaza w klasie –300 mm; b) wdrożyć monitorowanie tych pierwiastków (z wyjątkiem molibdenu) w koncentracie Balkhash ,w żużlu odpadowym Huty Miedzi Balkhash, charakteryzującym się bardzo złożoną matrycą elementarną. Opracowano, wdrożono i dokładnie przetestowano modyfikację stacji monitorowania rudy RLP-21T (firmy Aspap Geo LLC, Alma-Ata) do monitorowania online przepływów rudy srebra o niskiej jakości. Do fluorescencji rentgenowskiej zastosowano dyspersyjną metodę rentgenowską. Widma mierzono co sekundę. Zawartość srebra, kadmu i molibdenu obliczono na podstawie 40 pomiarów, a miedzi, cynku, ołowiu i żelaza – na podstawie 20 pomiarów.
EN
In paper the possibility of Cu2+ ions removing from aqueous solutions on selected synthetic ion exchange resins (Purolite S 910, S 930, S 940, S 950, C 160) was studied. These processes were described by the Langmuir and Freundlich adsorption models. It was found that the process of Cu2+ ions removing on S 910 and S 930 ion exchangers were the best described by linear equation form of Langmuir isotherm. The fit quality of the Freundlich isotherm is the best for S 940, C 160 and S 950 ion exchangers, which is confirmed by the obtained values of correlation coefficients R. The highest value of the maximum sorption capacity (about 69 mg/g) was obtained for C 160 cation exchange resin with sulfonic groups. For others ion exchange resins the monolayer capacity was decreasing in following order S 940 > S 930 > S 950 > S 910. The S 940 and S 930 ion exchangers were characterized by the highest affinity for Cu2+ ions. The amidoxime polyacrylic chelating resin S 910 was the least efficient. The differences in the affinity of the studied resins towards to Cu2+ ions can be explained by their different chemical or physical structure and particles size. In case of the studied ion exchange resins, the 1/n parameter values of the Freundlich isotherm were in range of 0.21–0.32. Therefore, it can be concluded that energy heterogeneity of the studied sorption system and intensity of Cu2+ ion removal on above ion exchangers are moderate. The K parameter value of the Freundlich equation was also highest for ion exchangers S 930 and S 940.
PL
Wykorzystanie modeli izoterm adsorpcji do opisu procesów usuwania jonów Cu2+ z roztworów wodnych na wybranych syntetycz¬nych żywicach jonowymiennych W pracy zbadano możliwość usuwania jonów Cu2+ z roztworów wodnych za pomocą syntetycznych żywic jonowymiennych firmy Purolite. Do badań wytypowano jonity chelatujące S 910, S 930, S 940, S 950 oraz kationit C 160. Badane procesy opisano za pomocą modelu adsorpcji Langmuira i Freundlicha. Stwierdzono, że liniowa forma równania izotermy Langmuira najlepiej opisuje proces usuwania jonów Cu2+ na jonicie S 910 i S 930. Jakość dopasowania izotermy Freundlicha jest najlepsza w przypadku jonitów S 940; C 160 i S 950 o czym świadczą uzyskane war-tości współczynników korelacji R. Największą wartość maksymalnej pojemności sorpcyjnej (ok. 69 mg/g) uzyskano dla kationitu C 160 z grupami sulfonowymi. Pojemność monowarstwy wyznaczona dla pozostałych jonitów chelatujących malała w szeregu S 940 > S 930 > S 950 > S 910. Największym powinowactwem do jonów Cu2+ cechował się jonit S 940 i S 930. Najmniej skuteczna okazała się amidoksymowa poliakrylowa żywica chelatująca S 910. Zaistniałe różnice w powinowactwie badanych żywic względem jonów Cu2+ można tłumaczyć ich odmienną budową chemiczną, strukturą fizyczną oraz wielkością cząstek. W przypadku badanych żywic jonowymiennych, wartości stałej 1/n izotermy Freundlicha znajdowały się w zakresie 0,21–0,32. Moż¬na zatem stwierdzić, że niejednorodność energetyczna badanego układu sorpcyjnego i intensywność procesu usuwania jonów Cu2+ na ww. jonitach jest umiarkowana. Wartość parametru K równania Freundlicha była najwyższa również dla jonitów S 930 i S 940.
EN
The Kushk-e-Bahram Manto-type Cu deposit is located in central Iran, within Eocene to Oligo–Miocene volcanic strata which occur in the central part of the Uremia-Dokhtar Magmatic Arc (UDMA). Propylitization, silicification, argillization and carbonatization are the main types of alteration to have affected the pyroclastic and volcanic rocks. There are high amounts of oxide minerals, including malachite, azurite, hematite, magnetite and goethite. Three types of primary FIs have been determined in the Kushk-e-Bahram deposit, namely; I: two-phase liquid-rich FIs (L+V), II: mono-phase liquid FIs, III: two-phase vapour-rich FIs which have been identified based on petrographical studies. Based on FI studies of co-existing quartz and calcite, homogenization temperatures (Th) must have been between 67 and 228°C, with an average of 158°C. Moreover, salinity is between 14.0–30.3 wt% NaCl, equivalent to a 19.6% average. Fluid density values vary from 0.8 to 1.1 gr/cm3. Based on FI data and related diagrams, the depth of their trapping was estimated to be <200 m and ore formation occurred at pressures of <50 bars. Consequently, mineralogy, host rock and FIs characteristics in the Kushk-e-Bahram deposit are similar to the Manto-type Cu deposits in Mesozoic-Cenozoic volcanic belts of Iran and South America.
PL
W artykule opisano nowo stosowaną w Narodowym Centrum Badań Jądrowych technologię odgazowania miedzi do potrzeb wysokiej próżni. Wysoka próżnia jest wymagana, w celu zapewnienia skutecznego przyspieszania elektronów w akceleratorach. Etapem osiągnięcia wystarczająco wysokiej próżni w strukturze jest odgazowanie termiczne wnętrza miedzianych wnęk rezonansowych, które stykają się z próżnią. Dotychczasowy proces odgazowania opierał się na prowadzeniu odgazowania wnętrza rezonatorów poprzez grzanie zewnętrznej powierzchni struktury w pomieszczeniu laboratorium. Nowa technologia polega na prowadzeniu procesu odgazowania w ograniczonej, izolowanej termicznie przestrzeni.
EN
The article describes the newly used bake-out technology for copper to meet the needs of high vacuum. High vacuum is required to ensure effective acceleration of electrons in accelerators. The stage of achieving a sufficiently high vacuum in the structure is bake-out of the interior of the copper resonant cavities that are in contact with the vacuum. The previous bake-out process was done by heating the outer surface of the structure in the laboratory. The new technology is conducted by a bake-out process in a limited, thermally insulated space.
EN
Saccharomyces cerevisiae, waste biomass originated from beer fermentation industry, was used to remove metal ions from four copper-containing synthetic effluents: Cu-Fe, Cu-Fe-Ni, Cu-Fe-Zn, and Cu-Fe-Ni-Zn. The characterization of the biomass surface was investigated by Scanning Electron Microscopy and Fourier-transform Infrared Spectroscopy. The adsorption behavior of Saccharomyces cerevisiae for copper, iron, nickel and zinc ions in aqueous solution was studied as a function of pH, initial copper concentration, equilibrium time, and temperature. Langmiur, Freundlich, Temkin and Dubinin-Radushkevich equilibrium models have been assessed to describe the experimental sorption equilibrium profile, while pseudo-first order, pseudo-second order, Elovich and the intra-particle diffusion models were applied to describe experimental kinetics data. Maximum sorption capacities have been calculated by means of Langmuir equilibrium model and mean free sorption energies through the Dubinin-Radushkevich model. Thermodynamic analysis results showed that the adsorption of copper, iron and zinc was spontaneous and endothermic in nature, while of nickel exothermic. Saccharomyces cerevisiae can be successfully applied for complex wastewater treatment.
EN
In the last few years, cationic layered clays, including bentonites have been investigated as potentialcatalysts for SCR DeNOxsystems. In this work, bentonite as the representative of layered clays wasmodified in order to obtain an alternative, low-cost NH3–SCR catalyst. Samples of raw clay wereactivated with HCl or HNO3, treated with C2H2O4and subsequently pillared with alumina by the ion-exchange. Afterwards, the modified materials were impregnated with iron and copper. The obtainedcatalysts were characterized by XRD and FT-IR. SCR catalytic tests carried out over analyzed samplesindicated the conversion of NO of approximately 90% for the most active sample. The type of acidused for modification and the type of active phase strongly influenced the catalytic properties of theanalyzed materials.
EN
The main aim of this work was to obtain a copper matrix surface composite using friction stir processing (FSP). The reinforced phase was SiC particles with an average size of 5 mm. The effect of the reinforcement on the microstructure, hardness and wear behaviour were analysed. The friction treatment was carried out using a truncated cone-shaped tool with a threaded side surface. Multi-chamber technology was used to produce the composite microstructure in the copper surface layer. Changes in the material microstructure were assessed by light microscopy and scanning electron microscopy. Comparative measurement of the hardness of the initial and treated material as well as wear resistance tests were also carried out. A favourable effect of the surface treatment on the microstructure and properties of the copper was found. As a result of the friction treatment there was strong grain refinement in the copper surface layer. The average grain size in the stirring zone was about 3 mm and was over 21 times smaller than the average grain size in the initial material. Intensive dispersion of the SiC particles in the modified layer was also found, leading to the formation of a copper matrix composite. The effect of microstructural changes in the surface layer of the material and formation of the surface composite was an over two-fold increase in the hardness of the material and an increase in wear resistance.
EN
In this study, the synthesis of copper-based multi-walled carbon nanotube compositesis described. Over the last years, carbon nanotubes (CNTs) have been widely used in many scientific research fields and have found applications in several sectors, e.g. for water treatment. This work focuses on combining the exceptional characteristics of CNTs, such as high specific surface areaand antibacterial properties, with the antimicrobial / antivirus features of copper oxides. The influence of synthesis parameters and thermal treatment on the final product was studied. Copper leakage was evaluated at both pH 5 and pH 7, confirming the possibility of applying Cu-based MWCNT composites in water filtration systems.
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