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    Wyświetlanie 1-15 z 15
    Tytuł:
    Effect of crystallinity and surface silanol groups on rheological properties of different sepiolites
    Autorzy:
    Çınar, Mustafa
    Gülgönül, Ilhan
    Ozdemir, Orhan
    Çelik, Mehmet S.
    Powiązania:
    https://bibliotekanauki.pl/articles/2146875.pdf
    Data publikacji:
    2022
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    sepiolite
    rheology
    crystallinity
    pH
    Opis:
    In this study, differences in the rheological properties of three different types of brown sepiolites (K1, K2, and K3) along with one beige (B) sepiolite with different physicochemical properties were explained based on their crystallinity and level of surface silanol groups. Towards this aim, SEM images, XRD and chemical analyses, cation exchange capacity (CEC), and water absorption tests were conducted along with surface area measurements and time-dependent pH profiles. The pH profiles at 3% by wt. revealed that each sepiolite sample attained the equilibrium at different times. These differences showed a parallel behavior with the degree of crystallinity. While sepiolite with better crystallinity (K1) was rather slow in reaching the equilibrium pH, the sepiolites with poor crystallinity (B and K3) reached their equilibrium pH more quickly. The rheological studies conducted with different sepiolites at 3% solids concentration exhibited time-dependent flow of the Bingham plastic model and thixotropic. Differences observed in the rheological behavior of sepiolites were found to correlate with the fiber size, CEC, surface area, and water absorption. The results further indicated that sepiolites with low crystallinity or high level of surface silanol groups (K3 and B sepiolites) show the best rheological properties.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2022, 58, 5; art. no. 153947
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Eliminating the adverse effect of the lime on the gold-bearing pyrrhotite flotation using the isopentyl xanthate as collector at low alkalinity
    Autorzy:
    Yang, Wei
    Wang, Qian
    Wang, Yaping
    Dong, Ping
    Powiązania:
    https://bibliotekanauki.pl/articles/110148.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrrhotite
    flotation
    pH regulator
    collector
    Opis:
    Flotation optimal conditions and mechanism of regulator lime, isopentyl xanthate and butyl xanthate on pyrrhotite were investigated by flotation test, contact angle, zeta potential and infrared spectroscopic analysis. It is found that there is a certain relationship between the regulator lime and the collector isopentyl xanthate. The results of flotation indicate that lime can indeed inhibit pyrrhotite, and isopentyl xanthate can decrease the depression effect of lime on pyrrhotite in low alkalinity. The results of adsorption mechanism of lime and isopentyl xanthate show that after lime adsorbed on the pyrrhotite surface, Ca 2+inhibit the adsorption of collector with the form of Ca(OH) 2 precipitates. Compared with butyl xanthate, isopentyl xanthate could reduce the generation of hydrophilic Ca(OH) 2 and generate less hydrophilic CaCO3 as well to decrease the negative effect of gold-bearing pyrrhotite flotation depressed by lime.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1250-1258
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Experimental study on electrokinetic of kaolinite particles in aqueous suspensions
    Autorzy:
    Min, F.
    Zhao, Q.
    Liu, L.
    Powiązania:
    https://bibliotekanauki.pl/articles/110918.pdf
    Data publikacji:
    2013
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    kaolinite
    zeta potential
    pH
    immersion time
    electrophoresis
    Opis:
    Influence of aqueous phase properties and process parameters on kaolinite particle zeta potential was quantified by electrophoresis experiments. The results indicated that pH strongly altered the zeta potential of kaolinite and it decreases at the beginning and then increases in the range of pH = 2–13. The activity of different cations changes the zeta potential and has the following tendency of Al3+ > Ca2+ > Mg2+ > Na+ and the zeta potential increases due to heterocoagulation of different mineral particles in suspension. It was found that the zeta potential of kaolinite particles increases after the suspension was stirred and decreases at the beginning, and then increases with soaking time. The FTIR results showed that the zeta potential takes into account ion adsorption and the change of Si–O, Al–O and Al–OH groups on the surface of the kaolinite particles.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2013, 49, 2; 659-672
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of pH and time on hydrodynamic properties of dodecylamine
    Autorzy:
    Zhou, X.
    Tan, Y. H.
    Finch, J. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/109853.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pH
    dodecylamine
    gas holdup
    froth height
    Frother function
    Opis:
    Gas holdup and froth height in the presence of dodecylamine (DDA, pKa = 10.63) are reported at three pH values. The results revealed a strong time effect for DDA: stability was reached at pH 3; not at natural pH, for example, gas holdup declining to the water only value; and at pH 11, while stability was reached quickly gas holdup was now less than in water alone indicating coalescence. In the first two cases, the time effect is attributed to loss of amine from the system as molecular amine, observed at natural pH as precipitates on the column wall. An argument for precipitation at pH < pKa is presented. At pH 11, coalescence is attributed to the oily nature of the molecular amine present as colloidal aggregates. Noting a difference in literature steady state gas holdup data at natural pH, it is speculated that varying steady states can be reached that corresponds to different levels of amine loss.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 4; 1237-1244
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of pH on surface characteristics and flotation of sulfidized cerussite
    Autorzy:
    Feng, Q.
    Wen, S.
    Zhao, W.
    Liu, J.
    Liu, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/110234.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    cerussite
    sulfidization
    excessive sulfide ions
    pH
    surface analysis
    Opis:
    The effect of pH on surface characteristic and flotation of sulfidized cerussite was studied by micro-flotation tests, dissolution experiments, scanning electron microscopy (SEM) energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS). The micro-flotation tests demonstrated that higher recovery of cerussite was achieved in acidic solutions than that in alkaline solutions. Despite the addition of high collector concentrations, cerussite flotation did not improved in alkaline solutions. The dissolution performance of sulfide-treated cerussite at different pH values indicated that the lead sulfide layer on the surface of sulfide-treated cerussite could exist in acidic solutions and it was more stable at acidic pH than in alkaline solutions. This finding was proved by the SEM-EDS and XPS analyses.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2016, 52, 2; 676-689
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of internal polyurethane coatings of cast iron pipes on the quality of transported potable water
    Autorzy:
    Zielina, Michał
    Młyńska, Anna
    Powiązania:
    https://bibliotekanauki.pl/articles/2171838.pdf
    Data publikacji:
    2022
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    drinking water
    polyurethane coating
    iron
    pH value
    CV
    coefficient of variation
    woda pitna
    powłoka poliuretanowa
    żeliwo
    wartość pH
    współczynnik zmienności
    Opis:
    The paper presents the results of laboratory tests to determine the effect of an internal polyurethane coating in ductile iron pipes on the quality of disinfected and non-disinfected drinking water. A decrease in the pH of water in contact with the polyurethane coating was found, which was slightly higher in the non-disinfected water than in the disinfected water. The coefficient of variation (CV) of the pH values for the chlorinated water samples was 5.02% and for the non-chlorinated water was 7.15%. The experiments also showed a rather large effect of polyurethane liner on the increase of TOC concentration in water. The presence of disinfectant further slightly increased the amount of organic compounds released. The CV values normalized to one day for TOC were as high as 193.32% and even 199.39% for disinfected water. A significant effect of polyurethane coating was observed on the color change and odor of water. On the other hand, there was no effect of polyurethane coating on alkalinity and chlorine consumption in water. The CV values normalized to one day in both cases were very small at 0.97% and 0.53%, respectively.
    Źródło:
    Environment Protection Engineering; 2022, 48, 3; 25--38
    0324-8828
    Pojawia się w:
    Environment Protection Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effect of pH value on effectiveness of biopolymer-based treatment of bauxite mine slurry
    Autorzy:
    Meng, Jian Ping
    Li, Shanmei
    Yan, Rongtao
    Wei, Changfu
    Powiązania:
    https://bibliotekanauki.pl/articles/24085778.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pH
    biopolymer
    xanthan gum
    bauxite mine slurry
    flocculation
    Opis:
    Effective dehydration and flocculation of mine slurries or sludge is important for nonferrous metal industries and environmental engineering. However, the mechanisms for the flocculation of slurry remain largely unclear. This paper presents the results of a series of flocculation tests, which was conducted on the slurry suspensions treated by xanthan gum (flocculant) at different pH values. It is shown that the settlement rate of mine slurry particles can be accelerated by adding xanthan gum, and the maximum sedimentation rate was obtained at a pH value of 5.9, and the final volume of flocs is significantly increased due to the addition of the flocculant. In addition, the settlement rates of xanthan gum-treated slurry suspensions at the pH values of 3, 5 and 7 decrease slightly compared with the reference slurry suspensions with pH=5.9, and the slurries remained stable as suspensions at the pH value of 9 and 11. The zeta potential measurement and SEM image analysis show that flocculation occurs primarily due to electrostatic attraction between slurry particles and the flocculants, and the bridging effect between the carboxylic groups in the side chains of xanthan gum molecule and the suspension particles.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 3; art. no. 167949
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ammonium chloride’s weakening effect on the copper activation of pyrite in flotation and the surface regulation mechanism behind it
    Autorzy:
    Zhang, Shengdong
    Chen, Yumeng
    Tong, Xiong
    Xie, Xian
    Lu, Yalin
    Powiązania:
    https://bibliotekanauki.pl/articles/110323.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pyrite
    depression
    cuprammonium solution
    pH buffering property
    flotation
    Opis:
    The traditional separation process of pyrite and marmatite is carried out under highly alkaline conditions. Therefore, a large amount of lime is demanded and the zinc recovery cannot be guaranteed. However, under weakly alkaline conditions, copper-activated pyrite has good floatability, which is difficult to separate from marmatite. In this paper, ammonium chloride (NH4Cl) is used for depressing the flotation of copper-activated pyrite to achieve the separation of these two minerals under weakly alkaline environment. The flotation tests show that NH4Cl can significantly reduce the floatability of pyrite in weakly alkaline conditions. The results of adsorption tests and X-ray photoelectron spectroscopy (XPS) analyses indicate that NH4Cl can obviously change the composition of pyrite surface by increasing the content of iron/copper hydroxide and reducing the content of copper sulfides. Calculation of the solution composition demonstrates that the addition of NH4Cl results in the occurrence of Cu(NH3)n2+ and the pH buffering property. Based on these results, it can be concluded that the depression of NH4Cl on copper activated pyrite is mainly derived from two aspects: 1) the pH buffering property of the conjugated acid-base pair (NH4+/NH3) can impede the decline of OH- concentration, which results in more hydroxide adsorbed on pyrite; 2) NH3 (aq) competes with the pyrite surface to consume Cu2+through complexation, which causes a reduction in the amount of copper sulfides formed on the pyrite surface.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 5; 1070-1081
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Depression effect of corn starch on muscovite mica at different pH values
    Autorzy:
    Peng, W.
    Zhang, L.
    Qiu, Y.
    Song, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/110573.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    muscovite mica
    corn starch
    pulp pH
    depression effect
    Opis:
    The depression effect of corn starch on the surface of muscovite mica powder at different pulp pH value was investigated. The experiments were performed on single mineral, and its flotation performance was studied by flotation tests, adsorption quantity measurement, zeta-potential technique and Fourier transform infrared (FT-IR). The results indicated that the depression effect was varied with the pulp pH value when dodecylamine chloride (DDA) was used as collector, the strongest inhibitory effect appeared at pH 2 and the zeta-potential of muscovite mica increased overall after conditioned with corn starch solution. It was confirmed by the FT-IR spectra that the corn starch indeed adsorbed on the surface of muscovite mica powder and physical adsorption was occurred between muscovite mica and corn starch. This study leads to a better understanding of the depression effect of corn starch on the surface of muscovite mica powder.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2016, 52, 2; 780-788
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Modeling of solubilization dynamics of manure organic matter and phosphorus as a function of pH control and enzyme supplementation
    Autorzy:
    Gungor, K.
    Alkan-Ozkaynak, A.
    Karthikeyan, K. G.
    Evrendilek, F.
    Gunasekaran, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/208150.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    biogeochemistry
    biological materials
    pH
    phosphorus
    biogeochemia
    materiały biologiczne
    fosfor
    Opis:
    The potential use of commercial enzyme and pH control has been investigated for enhancing dairy manure fermentation and modeling dissolved organic matter and orthophosphate (PO4-P) dynamics of fermenters. Anaerobic lab-scale batch fermenters (initial total solids concentration (TSo) = 3.8 wt. %) were fed with separated dairy manure solids and operated under pH controls (5 and 9.5). The enzyme-supplemented alkaline fermenters clearly outperformed the acidic fermenters in terms of chemical oxygen demand (COD) solubilization: ca. 50% vs. 20%, respectively. Soluble PO4-P in the acidic fermenters was comparably higher but constituted less than 20% of total phosphorus. Better soluble COD (>80%) and soluble PO4-P (>70%) yields were noted for the dilute fermenters (TSo = 0.6–0.8 wt. %). An existing model was retrofitted, calibrated and validated for simulating dynamics of soluble COD, volatile fatty acids, and soluble orthophosphate under various pH and enzyme conditions.
    Źródło:
    Environment Protection Engineering; 2016, 42, 2; 155-170
    0324-8828
    Pojawia się w:
    Environment Protection Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nonequivalent adsorption of pH-responsive dicephalic sugar surfactants at the air/solution interface
    Autorzy:
    Lamch, Ł.
    Jarzycka, A.
    Szyk-Warszyńska, L.
    Warszyński, P.
    Wilk, K. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/109968.pdf
    Data publikacji:
    2018
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    bis-aldonamide surfactants
    adsorption
    STDE model
    pH
    electrolyte influence
    Opis:
    The present work contributes to the analysis of the effect of electrolyte and pH on the adsorption of dicephalic N-dodecyl-N,N-bis[(3-D-aldonylamido) propyl]amines (aldonyl = gluconyl and lactobionyl) at the air/water interface. The headgroup of these surfactants consists of two amide groups connected by a central tertiary amine, which may be protonated in an aqueous environment. We performed measurements of surface tension isotherms of aqueous solutions of the studied dicephalics in the presence of NaCl and NaOH and applied the STDE model for evaluation of the experimental results. They showed that the adsorption of the surfactants at the air/water interface was pH- and electrolyte- dependent, since addition of NaCl and NaOH had different effects on the surface activity and critical micelle concentration values (CMC). The theoretical model reflected well the surface tension isotherms obtained for a broad range of surfactants concentration, confirming the theoretical predictions concerning the protonation of tertiary amines, which was additionally supported by the measurements of solution pH.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2018, 54, 1; 102-110
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Buffering of pulp pH and its influence on process water chemistry during iron ore flotation
    Autorzy:
    Tang, Min
    Xiao, Qingfei
    Powiązania:
    https://bibliotekanauki.pl/articles/1446441.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    pulp pH
    buffering
    water chemistry
    mineral dissolution
    iron oxide
    Opis:
    It is inevitable for the occurrences of pulp pH buffering during pH control in flotation as the minerals with acidic/alkali properties tend to interact with pH modifiers and restore the pulp pH. This could result in some disturbing ions and alter the water/pulp chemistry. The purpose of this study was to identify the influences of pulp pH buffering on process water chemistry through a series of pH buffering tests, bench flotation experiments, ore dissolution tests, zeta potential measurement, and Xray diffraction (XRD) analysis. The built-up and distribution of the dominant cations in the process water from different locations in an industrial flotation system of the iron ore were analyzed and recorded by Inductively Coupled Plasma-Optical Emission (ICP-OES) at a period of about six months when the operations were stable. The data showed that a near five-minute buffer of pulp pH at a range from near 7.9 to 8.9 occurred before it reached a stable value. At this period, the dissolution of Ca/Mg from the iron ore was dominant. And, the pulp pH at a lower value tended to induce more dissolved $Ca^{2+}$ and $Mg^{2+}$ ions. These divalent cations seem to have different influences on the flotation properties of iron oxides at the same concentrations, indicating a positive effect on the recovery of iron oxides with the presence of $Mg^{2+}$ ions but an opposite effect if $Ca^{2+}$ ions occurred. The presence of sulfate, however, tended to restore the floatability of silicate depressed by $Ca^{2+}$ ions.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 4; 157-167
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Significance of reagents addition sequence on iron anionic reverse flotation and their adsorption characteristics using QCM-D
    Autorzy:
    Hou, Ying
    Sobhy, Ahmed
    Wang, Yue
    Powiązania:
    https://bibliotekanauki.pl/articles/1448929.pdf
    Data publikacji:
    2021
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    iron oxide
    adsorption
    pH modifier
    starch
    reverse flotation
    QCM-D
    Opis:
    To explore the influence of reagents addition sequence of the pH regulator and the starch depressant on the anionic reverse flotation of iron oxide, flotation conditional experiments were performed on mixed low-intensity and high-gradient magnetic concentrates which is the flotation feed acquired from the iron processing plant. Besides, quartz crystal micro-balance with dissipative (QCM-D) was conducted to detect the adsorption phenomena of the flotation reagent on iron oxide sensors at different addition orders. The outcomes showed that the flotation performance using the pH regulator prior to the depressant was the best. For example, at 1.6 kg/Mg starch dosage, the recovery and separation efficiencies were improved by 18.3% and 21.2%, respectively, with keeping the concentrate Fe grade as high as 69.5%. Also, QCM-D frequency shifted by -41 Hz from 17 Hz to -24 Hz with increased dissipation from -2.6 x 10-6 to 8.2 x 10-6, indicating an increase in the mass of slightly-rigid starch adsorption layer on the surface of iron oxide under a strong alkaline condition with adsorption density of about 0.46 mg/cm2. On the other hand, under weak alkaline conditions, starch was adsorbed, and then the starch was desorbed upon the addition of the strong alkaline solution. Whereas, adding the pH modifier to create a strong alkaline condition enhanced the starch adsorption significantly with coordination and hydrogen bonds, and prevented the following adsorption of the anionic collector for more efficient reverse flotation of iron oxide minerals.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2021, 57, 1; 284-293
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Pourbaix diagrams for copper ores processing with seawater
    Autorzy:
    Marín, Oscar A.
    Ordóñez, Javier I.
    Gálvez, Edelmira D.
    Cisternas, Luis A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1449342.pdf
    Data publikacji:
    2020
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    Pourbaix-diagram
    Eh-pH diagrams
    seawater
    copper minerals
    Chilean mining
    Opis:
    Decreases in the copper grade, waste disposal, energy supply, and water scarcity are some of the most critical challenges for the copper mining industries. One of the alternatives to counteract the water scarcity is the use of seawater, whether raw, partially desalinated, or desalinated. The use of seawater implies the generation of several compounds as a result of the interaction of ions in waters and ores. For this reason, it is required a greater understanding of these compounds generated on mineral processing, being Pourbaix diagrams used to estimate the possible compounds that will be formed in an aqueous medium for a given metal ore. In this paper, the effect of temperature, salinity, and Cu-concentration on the stability of the copper-solid species was investigated by constructing Pourbaix diagrams for different copper ore types with seawater. The results show that the corrosion areas decrease when the temperature increases for both oxidized and sulfide minerals. It was confirmed that the concentration is a critical variable that influences the size of corrosion areas. In terms of the effect of the other ions that seawater contains, carbonate, chloride, and bromide affect the stability of the Cu-solid species. The proposed diagrams serve as a useful tool to predict the stable species that may be obtained when seawater is used. The use of seawater in mining is an essential issue because it is considered as a more sustainable alternative instead of use freshwater or desalinated seawater, especially in locations with complex water availability, as is northern Chile.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2020, 56, 4; 625-640
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Measurements of AlGaN/GaN heterostructures for sensor applications
    Autorzy:
    Hojko, M R
    Paszuk, D
    Paszkiewicz, B
    Powiązania:
    https://bibliotekanauki.pl/articles/174545.pdf
    Data publikacji:
    2013
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    sensor
    AlGaN/GaN heterostructure
    electrolyte
    two-dimensional electron gas (2DEG)
    pH
    Opis:
    In the paper, the behavior of AlGaN/GaN HEMT-type heterostructures in a water solution of (KOH + HCl) with differing pH was studied. The influence of the electrolyte pH on channel pinch-off voltage was measured using impedance spectroscopy methods. It was observed that the change of the pH of electrolyte has a strong effect on the pinch-off voltage of AlGaN/GaN HEMT-type heterostructures independently of the concentration of other ions. In high-pH environment the so-called memory effect of heterostructures was revealed. Its possible origin was discussed. A general theory to explain all results was proposed.
    Źródło:
    Optica Applicata; 2013, 43, 1; 35-38
    0078-5466
    1899-7015
    Pojawia się w:
    Optica Applicata
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-15 z 15

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