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EN
A technology for producing gold films on the surface of fabric materials has been developed, which provides for preliminary wetting of the fabric product with aqueous solutions of gold (III) chloride. In this case, a sorption layer of gold chloride is formed on the surface of fabric materials. Then, when drying these products under sunlight, physicochemical and photochemical processes occur, leading initially to the formation of monovalent gold chlorides, which, having semiconductor properties, provide the release of elemental gold. After washing of by-products on the surface of the material remains an ultra-thin film of gold, which has a sufficiently strong grip on the base. Since the proposed technology does not require special equipment it can be used to apply functional films of gold on various products of technical, household and medical purposes.
EN
El-Hudi gold deposit, located in the South Eastern Desert of Egypt, represent large vein- type gold occurrence. The representative sample revealed the abundance of quartz as main constituent with minor amounts of mineral impurities. Gold was detectable (12 g/t) as determined using atomic absorption. The petrographic study revealed that the gold grains ranged from 10-40 μm. The grain boundaries of quartz are highly stained with iron minerals as hematite and limonite. Sericite mineral is common in discrete gold-bearing veins. Eroded pyrite was detected with high alteration leaving only cubic-shaped cavities behind. Different techniques for gravity separation were used to separate gold from the quartz mineral. After crushing and grinding of the sample, shaking table was used to upgrade the coarser fractions while Falcon concentrator was employed to upgrade the fine fraction. The best concentrate was obtained through grinding the whole sample to less than 0.2 mm, followed by cleaning steps. The gold content is increased from 12 to 145 g/t with total recovery of 78%.
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.
EN
The main objective of this study was to quantitatively and qualitatively idenify trace metal admixtures in ore mineralsfrom Fe-Ti-V ore deposits within the Suwałki Anorthosite Massifin NE Poland. Chemical composition of ore minerals was determined using the CAMECA SX-100 electron microprobe and scanning electron microscope. The most abundant trace elements were Ti and Vhosted in oxides and Co, Ni, Cu, Zn contained in sulphides such aspentlandite, pyrrhotite, chalcopyrite, pyrite, siegenite, millerite. Scarce occurrences of native Bi, hessite and greenockite were identified. Samples, which were depleted in iron oxides were enriched in REE due to the presence ofzircon, apatite and monazite.
EN
Thiosulfate (TS) process for extraction of gold and silver is a promising alternative to the highly toxic cyanidation process. One of the main reasons caused limiting the practical application of the TS process is the poor recovery of gold and silver on the commonly used activated carbon (AC). Increasing amounts of TS ions greatly inhibited the adsorption of gold and silver from synthetic solutions. No adsorption was obtained when the TS concentration reached 0.8 M after 5 h. The adsorption efficiency from real leach liquor initially contained 0.2 M TS was as low as 40-50%, after a long time of 15 hours. We have suggested that the removal of the residual TS ions in leach liquor through an interaction with an oxidizing agent such as ammonium persulfate (APS) would improve the adsorption of gold and silver on AC. Increasing the APS concentrations from 0.0 M to 0.01 M drastically improved the gold adsorption efficiency from 5% to 85% after only 10 min. Almost 95% of both metals was adsorbed after 90 min. EDXRF chart confirmed the adsorption of gold and silver on AC. A process flowsheet was proposed for an integrated TS leaching and recovery of gold and silver from Al Amar tailing including adsorption on AC in presence of APS.
EN
Naturally, refractory gold is enclosed by sulfide minerals such as pyrite and arsenopyrite and a higher content of organic carbon, which results in difficulty in the recovery of gold. In this study, the flotation gold concentrate before and after pressure oxidation (POX) was analyzed. The analysis of the Eh-pH diagram revealed that pyrite/arsenopyrite would be dissolved in higher oxidation potential. Results of SEM-EDS showed that the surface of minerals became very rough and structure of some particles was destroyed after POX. The XRD measurement showed that pyrite was oxidized to jarosite, and gangue minerals such as quartz and organic carbon were hardly changed. The process of thiosulfate leaching of gold was designed and optimized according to Miscellaneous implemented by Response Surface Methodology (RSM). Based on the results of ANOVA, leaching model was significant. In leaching, [S2O32-] played an important role and the interactions between [S2O32-] and [Cu2+] were significant. The effect of [HA] was relatively weak. Optimum process parameters of the initial reagent concentration were 505.00 mM for [S2O32-], 34.77 mM for [Cu2+], and 0.50 mM for [HA]. Under these conditions, the Au extraction value was about 86.21%, which was significantly higher than that obtained with leaching directly.
PL
W artykule przedstawiono sposób syntezy nanokompozytu węglowego z nanocząstkami złota (warstw C-Au), charakteryzację oraz potencjalne możliwości aplikacyjne warstw w oparciu o ich właściwości fotoelektryczne i/lub fototermiczne. Omówione zostały wyniki badań topografii warstw otrzymane metodą skaningowej mikroskopii elektronowej, morfologii - metodą spektrometrii rentgenowskiej z dyspersją energii, budowy krystalicznej - metodą dyfrakcji promieniowania rentgenowskiego i struktury elektronowej - metodą spektroskopii w zakresie światła widzialnego oraz bliskiego ultrafioletu.
EN
In this article the method of synthesis of carbon nanocomposite materials with gold nanoparticles was presented. The characterization and potential application of this films based on their photoelectric and / or photothermal properties were shown. The results of topography studies obtained by scanning electron microscopy, morphology - X-ray spectrometry with energy dispersion, crystal structure - X-ray diffraction and electron structure - visible and near ultraviolet spectroscopy are discussed.
8
Content available remote Silver and gold ions recovery from batch systems using Spirulina platensis biomass
EN
In order to assess ability of Spirulina platensis to recover silver and gold ions from the environment the bioaccumulation of silver and gold ions and their effect on growth, proteins and carbohydrates content of Spirulina platensis biomass was studied. Silver nitrate (AgNO3) in concentration range 0.01-1 mg/dm3 and tetrachloroaurate Na[AuCl4] in concentration range 18.5-370 mg/dm3 were added as component of the Spirulina platensis cultivation medium. In case of silver two cultivation media were studied: standard and Cl-free. The process of silver and gold uptake was traced using neutron activation analysis. Presence of silver ions in standard cultivation medium reduced biomass productivity by 66 %, while in Cl-free biomass productivity was reduced by 11.8 % only. The reduction of proteins content by 30 % in Cl-free medium and by 19 % in standard medium was also observed. The experiments showed that in case of gold ions loading, the biomass productivity and protein content were reduced only at high Na[AuCl4] concentration in the medium. The behaviour of carbohydrates content change was similar under silver and gold loadings: decrease at low metal concentration followed by increase at high metal concentrations. Scanning electron microscopy allowed observation of spherical metal nanoparticles, which were formed extracellularly during silver and gold bioaccumulation. Spirulina platensis can be used for recovery of precious metals as well as metal nanoparticles production.
EN
Nanoparticles are very fascinating area of science not only due to their unique properties but also possibility of producing new more complex materials, which may find an application in modern chemistry, engineering and medicine. In process of nanoparticles formation very important aspect is a rate of individual stage i.e. reduction, nucleation and autocatalytic growth, because this knowledge allows for proper materials design, morphology manipulation, stability. The last one aspect can be realized using proper electrostatic, steric and electrosteric stabilization. However until now nobody reports and measures kinetic rates of all stages during process of particles formation in the presence of steric stabilizers. Thus, the main contribution of this paper is determination of individual rate constants for nanoparticles formation in the presence of steric stabilizers and their comparison to the system without stabilizer. For this purpose, an aqueous solution of Au(III) and Pt(IV) ions were mixed with steric stabilizers like PVA and PVP, and reduced using L-ascorbic acid as a mild and sodium borohydride as a strong reductant. As a results stable nanoparticles were formed and process of their formation was registered spectrophotometrically. From obtained kinetic curves the values of observed rate constants for reduction metal ions, slow nucleation and fast autocatalytic growth were determined using Watzky-Finke model. It was found that the addition of polymer affects the rate of the individual stages. The addition of steric stabilizers to gold ions reduced with L-ascorbic acid causes that the process of nucleation and autocatalytic growth slows down and the value of observed rate constants for nucleation changes from 3.79·10-3 (without polymer) to 7.15·10-5 s-1 (with PVA) and for growth changes from 1.15·103 (without polymer) to 0.48·102 s-1 M-1 (with PVA). However, the rate of the reduction reaction of Au(III) ions is practically unchanged. In case of using strong reductant the addition of polymer effects on the shape of kinetic curve for reduction of Au(III) and it suggests that mechanism is changed. In case of Pt(IV) ions reduction with L-ascorbic acid, the process speeds up a little when PVA was added. Determined values of observed rate constants for nucleation and growth platinum nanoparticles decrease twice comparing to the system without polymer. The reduction of Pt(IV) ions with sodium borohydride accelerates when PVP was added and slows down when PVA was used. Moreover, the size of obtained colloidal gold and platinum was also analysed using DLS method. Obtained results (rate constants) may be useful in the process of nanomaterials synthesis, in particular in microflow.
EN
The demandfor important raw materials for the Chinese economy achieved the scale about the half of the world's demand. Investment decisions taken in this matter enable a complete identification of mineral deposits, which is significant for both domestic and foreign investments. Geological studies and prospecting for useful ore mineral deposits have been conducted by special research institutions that prepare information about their reserves and output profitability. The University of Geological Studies in Beijing, with about 40,000 students, plays a key role in this activity. For example, a development of both reforms in extracting bituminous coal and gold deposits was discussed.
11
Content available Physical separation route for printed circuit boards
EN
Recently, the consumption of electrical and electronic equipment (EEE) has increased with the advanced technology. A wide range of components made of metals, plastics and other substances are contained in EEE. Electronic waste (e-waste) is easily demounted and separated by manually methods; however, printed circuit board (PCB) which is one the most common components of e-waste need to be recycled with economic and environmental technologies. In this paper, employing physical separation methods to ground waste PCB, an eco-friendly, simple and environmental process for separation of valuable metals was designed and proposed. A heavy fraction with 40.8% Cu, 350 ppm Au and 475 ppm Ag content at recovery of 95.4% Cu, 77.7% Au and 65.1% Ag was obtained from a feed assaying 12% Cu, 130 ppm Au and 200 ppm Ag using shaking table separator. Cu grade was increased from 52.4% to 73.9% with the recovery over 92% by dry magnetic separator and copper alloys were separated from the waste matrix with 98% Cu recovery using electrostatic separator.
EN
Some Saudi gold ores, such as that at Al-Amar mine, suffer from low leaching efficiency using the toxic cyanidation process. Only about 60% of the gold and 26% of the silver in the feed ore can be extracted at 0.2% CN– after 24 h and the rest percentages of these metals remained in leaching residues (tailings). These tailings contained 1.1 ppm Au and 4.3 ppm Ag. Reprocessing of tailings serves both for economic and environmental reasons. A petrography analysis of the mineral constituents indicated that the rock samples consisted primarily of sphalerite, chalcopyrite, pyrite and galena in decreasing order of abundance. An electron probe microanalysis quantitatively showed that gold and silver were finely distributed in the grain boundaries and within sphalerite, chalcopyrite, pyrite, and quartz. The dissemination of gold and silver in these hard minerals may be the main reason for their low recovery by cyanidation. Open air roasting of the tailings can release amounts of the disseminated gold and silver which can be extracted during leaching with the harmless thiosulfate ion S2O32–. After studying the different parameters, we found that the maximum possible extraction of gold and silver from the tailings roasted for 2 h at 400°C reached about 50% at 0.2 M ammonium thiosulfate, 0.3 M ammonium hydroxide, solid–liquid ratio ½ for 24 h. These achievements represent a possible exploitation of the accumulated 1.65 million Mg tailing waste containing significant amounts of gold and silver valued at about $73 million.
13
Content available Valorisation of Mining Waste for Gold Recovery
EN
Purpose: the metals and industrial minerals contained in the tailings produced by mining and quarrying activities, are cause of environmental damage. The objective of this experimental work is the application of innovative technologies for the treatment and exploitation of mining tailings in Romania, in order to recover materials high grade raw to be placed on the market, reducing the volume of the wastes. Further objective, is to optimize some parameters relating to the dissolution of gold and the subsequent recovery from purified solutions, determining beforehand the technical feasibility of the scheme of process developed on a laboratory scale. Methods: the study is focused on hydrometallurgical process for the recovery of gold. The innovative treatment chosen is the thiosulphate process that, compared to conventional cyanide, has several advantages, first of all the most eco-friendly and non- toxic to humans. The conventional process shows operating limits in the case of auriferous minerals refractory materials, such as Romanian wastes object of the study. Another fundamental characteristic of the ammoniacal thiosulphate solutions, is the best selectivity towards gold, not attacking the majority of the gangue mineral constituents. Results: the dissolution rates of gold reached a final value of 70% Au – working at room temperature – with recoveries of the global process of about 65%, in line with the conventional process. Main conclusions: these results are very encouraging, considering that this is an innovative process, applied to a low content gold ore. The optimization of parameters and operating conditions, and the industrial treatment, continuous and scale greater would certainly permit to reach the best results in terms of process yields and energetic and reagents consumption.
PL
Cel: metale i minerały zawarte w odpadach powstających w wyniku działalności górniczej i wydobywczej są przyczyną szkód w środowisku. Celem prac eksperymentalnych jest zastosowanie innowacyjnych technologii do obróbki i eksploatacji odpadów wydobywczych w Rumunii, w celu odzyskania wysokiej jakości surowców, które zostaną wprowadzone do obrotu, zmniejszając ilość deponowanych odpadów. Dalszym celem jest optymalizacja niektórych parametrów związanych z rozpuszczaniem złota i późniejsze odzyskiwanie z oczyszczonych roztworów, z określeniem technicznej wykonalności schematu procesu opracowanego w skali laboratoryjnej. Metoda: badanie koncentruje się na procesie hydrometalurgicznym odzyskiwania złota. Innowacyjnym sposobem jest zastosowanie do ługowania tiosiarczanu, który w porównaniu z tradycyjnym cyjankiem ma wiele zalet, przede wszystkim jest bardziej przyjazny dla środowiska i nietoksyczny dla ludzi. Konwencjonalny proces daje ograniczone wyniki dla badanych odpadów złotonośnych. Podstawową zaletą amoniakalnych roztworów tiosiarczanu jest lepsza selektywność w stosunku do złota, a nie ługowanie wszystkich składników mineralnych skały płonnej. Wyniki: wskaźniki rozpuszczania złota osiągnęły wartość 70% Au - w temperaturze pokojowej - w porównaniu do odzysku z procesu konwencjonalnego około 65%. Główne wnioski: wyniki są bardzo zachęcające, proces jest innowacyjny, zastosowany do rudy o niskiej zawartości złota. Optymalizacja parametrów i warunków pracy oraz wdrożenie w skali przemysłowej pozwoli osiągnąć lepsze wyniki pod względem wydajności procesu oraz zużycia energii i odczynników.
PL
To miał być artykuł na koniec wakacji, ale może dobrze się stało, że napisałem wtedy nieco bardziej rozrywkowy tekst o podróżowaniu. Ten poniżej zmusza do chwili refleksji i wpisuje się w szeroko dyskutowany problem wzrostu zapotrzebowania i spadku wystarczalności surowców mineralnych, a także pogoni za nimi.
PL
Przedstawiono wyniki analiz składu chemicznego złota okruchowego z potoku Jamna oraz obecnych w nim inkluzji kruszców. Rezultaty badań wykorzystano w identyfikacji obszarów alimentacyjnych miejscowych wystąpień rozsypiskowych. W aluwiach potoku Jamna ziarna złota jednofazowego z wrostkami galeny, arsenków i siarkoarsenków Co-Fe-Ni współwystępują z ziarnami złota dwufazowego, zawierającego fazy Hg-nośnego elektrum. Zróżnicowanie składu chemicznego ziaren świadczy o pochodzeniu złota z dwóch odmiennych genetycznie obszarów źródłowych: polimetalicznych żył hydrotermalnych oraz okruszcowanych skał osadowych permu.
EN
Results of the chemical composition of the gold grains from Jamna stream and occurring inclusions of ore minerals have been presented. Results have been used to identify the potential alimentary areas of the placer gold grains. Gold grains from the alluvial deposits of Jamna stream is represented by single-phase gold with inclusions of galena, Co-Fe-Ni arsenides, sulpho-arsenides and by biphasic gold, containing Hg-bearing electrum. Differentiation of the grain’s chemical composition is an evidence of the gold’s origin from two genetically distinct source areas: polymetallic hydrothermal veins and ore-bearing Permian sedimentary rocks.
PL
Przedstawiono historyczne przykłady rozwiązań organizacyjno-prawnych związanych z eksploatacją surowców mineralnych. Wybrane przykłady obejmują złoto, guano i bursztyn i ilustrują problemy prawno-społeczne związane zarówno z występowaniem surowców poza obszarem suwerenności danego państwa jak i problemy związane z trudną do udokumentowania zasobów formą występowania złóż. Opisane rozwiązania obejmują zarówno pełną liberalizację poszukiwań i wydobycia małych złóż okruchowych (złoto; Rosja, USA) jak i militarne i polityczne wsparcie państwa przy akwizycji obszarów perspektywicznych (guano; USA). Szczególną uwagę poświęcono bursztynowi dla którego zaproponowano rozważenie możliwości liberalizacji podobnej do stosowanej w przypadku małych złóż złota w Rosji, zarówno carskiej jak i posowieckiej.
EN
Historical examples of organizational and legal solutions related to the exploitation of mineral resources are presented. Selected examples include gold, guano and amber and illustrate legal and social problems related to both the occurrence of raw materials outside the sovereignty of a given country, as well as problems related to the difficulties in evaluation of resources. The solutions described include both full liberalization of exploration and exploitation of small placer deposits (gold, Russia, USA) as well as military and political support of the state in the acquisition of prospective areas (guano, USA). Particular attention was paid to amber, for which it was proposed to consider the possibility of liberalization similar to that used for small gold deposits both in Tsarist and post-Soviet Russia.
PL
Przeprowadzono badania mineralogiczne ziarn zlota wystepujących w piaskach i żwirach wPodleciu-Gęstwinie w Górach Złotych. W badaniach wykorzystano mikroskopie skaningową i spektroskopie (EDS). Stwierdzono wysoką czystośc złota i śladowe domieszki Mg, Pb. Ag i F. Wykonano także oznaczenia składu petrograficznego skał w których występuje badane złoto. Stwioerdono, że zbudowane są one głównie z ziarn amfibolitów, gnejsów i róznych odmian łupków metamorficznych.
EN
Mineralogical investigation of small grains of gold present at sands and gravels of Podlesie-Gestwina (Golden Mountains- South Poland) were performed using SEM and EDS methods. Results document high concentration of gold and small admixture og Mg, Pb, Ag, and F. Petrographic compozition of sediments was determined too. The main component is represented by metamorphic rocks (amphiobolites, gnaisess and metamorphic shists.
18
PL
Autorzy przedstawiają opis górnictwa złota w rejonie masywu ryolitowego Wielisławki na Pogórzu Kaczawskim, na podstawie wyników kwerendy kartograficznej i bibliograficznej, analiz numerycznych modeli terenu LiDAR, a także prac terenowych. Niniejszy materiał wzbogacają m.in. dwie unikalne mapy, które należą do najcenniejszych dzieł kartografii górniczej na terenie Polski. Powstały one około 1556 r. jako materiał pomocniczy dla rozpatrzenia konfliktu, do jakiego doszło pomiędzy właścicielami ziemskimi a górnikami z kopalni złota na Wielisławce.
EN
This paper presents the history of the gold mining activity within the Wielisławka Hill in the Kaczawskie Foothills. The results are based on a cartographic study of bibliographical research, LIDAR DTM analysis and field work. The article contains e.g. two unique maps from the collection of the State Archive in Prague which belong to the most relevant works of the cartography of mining in Poland. They have been drawn in or around 1556 as a supplementary material for the settlement of a dispute between land owners and miners from the Wielisławka gold mine. The article demonstrates that the gold mining in the Wielisławka massif had taken place on a much larger scale than hitherto expected. The mining operation has left relics in the form of sink hole fields, heaps, adits and underground galleries entering the massif of the hill by the Kaczawa river. The Wielisławka massif is nowadays a valuable destination for geotourism.
EN
Detailed morphological and geochemical studies of placer gold grains and other heavy minerals from Cenozoic fluvial clastic sediments in the area of the Zimnik Creek drainage basin (North Sudetic Trough, Lower Silesia) allowed the description of their specific features: shape and morphology, flatness index, internal textural features and chemical composition of the gold grains. It enables an estimation of the distance from the source area and determination of the source of the ore mineralisation, along with establishing the feeder areas for placer mineralisation including Rote Fäule-related gold hosted by Rotliegend-Zechstein transitional sediments. The comparison of the heavy mineral contents of placer grains from the Zimnik Creek drainage basin makes it possible to identify the area of origin for the gold particles. The crystalline Au-Ag-Pd-Hg (polymetallic) alloy grains of fluvial gold are assumed to come from the transitional sediments between the Rotliegend and the Zechstein in the North Sudetic Basin. The morphological and geochemical features of the polymetallic grains strongly suggest that the grains from the upper course of the Zimnik Creek valley sediments represent what has eroded from the local gold mineralisation and this mineralisation is probably in the vicinity of the upstream sampling site. The bimodal chemical composition of the Au-Ag-Pd-Hg alloy grains with electrum and medium-Ag grains (<15 wt.% Ag) found in the study area is typical of the Rote Fäule and Kupferschiefer-related gold mineralisation on the southern side of the North Sudetic Trough and the Sieroszowice-Polkowice copper mining district of the Fore-Sudetic Monocline. The study of the Ag contents of placer grains from the Zimnik Creek drainage basin highlights the contrast between the placer gold grains derived from Paleozoic orogenic gold mineralisation in the Sudetes (typically simple Au-Ag alloys containing between 5 and 20 wt.% of Ag) and the one formed by the oxidizing chloride hydrothermal systems. The grains identified in this manner as originating from the oxidizing hydrothermal system of the transitional zone can be distinguished from the placer gold derived from other styles of mineralisation, which are not Rote Fäule-related. It is particularly important considering the ongoing reconnaissance exploration in the North Sudetic Trough (SW Poland), which employs gold grain analyses as a prospecting tool for the detection of potentially economic primary gold mineralisation.
EN
Rapid synthesis of gold nanoparticles (AuNPs) by pulsed electrodeposition was investigated in the non-aqueous electrolyte, 1-ethyl-3-methyl-imidazoliumbis(trifluoro- methanesulfonyl)imide ([EMIM]TFSI) with gold trichloride (AuCl3). To aid the dissolution of AuCl3, 1-ethyl-3-methyl-imidazolium chloride ([EMIM]Cl) was used as a supporting electrolyte in [EMIM]TFSI. Cyclicvoltammetry experiments revealed a cathodic reaction corresponding to the reduction of gold at −0.4 V vs. Pt-QRE. To confirmthe electrodeposition process, potentiostatic electrodeposition of gold in the non-aqueous electrolyte was conducted at −0.4 V for 1 h at room temperature. To synthesize AuNPs, pulsed electrodeposition was conducted with controlled duty factor, pulse duration, and overpotential. The composition, particle-size distribution, and morphology of the AuNPs were confirmed by field-emission scanning electron microscopy (FE-SEM), energy-dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The electrodeposited AuNPs were uniformly distributed on the platinum electrode surface without any impurities arising from the non-aqueous electrolyte. The size distribution of AuNPs could be also controlled by the electrodeposition conditions.
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