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EN
It has been shown that the precipitation of bismuth orthovanadate from a fly ash leachate is a promising method of vanadium recovery. BiVO4 obtained after appropriate heat treatment can be sold as a pigment. The yield of recovery of solubilised vanadium is equal to 68% and the precipitate is free from nickel impurity. The precipitate is insoluble in the solutions with pH ≥ 3. In more acidic media the solubility of precipitate increases with the decreasing pH. The solubility of the precipitate increases also with the increasing concentration of chloride ions.
PL
Wanad należy do grupy metali nieżelaznych, stanowiący jeden z podstawowych dodatków do stopów z przeznaczeniem na narzędzia. Obecność wanadu w stopach, znacząco poprawia właściwości mechaniczne. Niestety jego wysoka cena powoduje, iż na rynku pojawiają się fałszywe stopy, które rzekomo mają posiadać wanad lub jego zawartość jest zaniżona względem optymalnych parametrów. Ze względu na jego wysoką cenę, ograniczone źródła naturalne oraz jego toksyczność, koniecznym jest rozsądne i przemyślane zarządzanie zasobami, oraz odpadami zawierającymi ten metal oraz jego sole. W pracy przedstawiono przegląd literatury na temat recyklingu wanadu i jego źródeł antropogenicznych.
EN
Vanadium belongs to the group of non-ferrous metals, which is one of the basic additions to alloys for tools. The presence of vanadium in the alloys, significantly improves mechanical properties. Unfortunately, its high price results in the appearance of false of alloys on the market that allegedly have vanadium. Due to its high price, limited natural sources and its toxicity, it is necessary to have a reasonable and well thought-out management of resources and waste containing this metal and its salts. The following paper presents an overview of the literature on vanadium recycling from its anthropogenic sources.
EN
Crystallization of γ-glycine in the presence of selected concentration (9 g/mL) of tailor-made additive magnesium sulfate heptahydrate salt (MgSO4·7H2O) has been studied at ambient temperature by adopting slow solvent evaporation procedure. The morphological modifications of glycine crystals grown from pure aqueous solutions of glycine and from glycine solutions containing magnesium species in the amount of 0.1 g/mL to 16 g/mL have been investigated thoroughly. The crystalline nature and phase identification of the crystalline material were confirmed by X-ray powder diffraction and SXRD studies. NMR studies revealed the information about the molecular conformation in solution, phase changes, functional groups and chemical environment. FT-IR spectra revealed distinct difference between α and γ-glycine polymorphs in the region around 880 cm−1 to 930 cm−1. The grown γ-glycine crystal had a lower cut-off value at 200 nm and the bandgap value evaluated from the Tauc plot was found to be 5.83 eV. The marked differences between α and γ-polymorphs of glycine were also revealed by DSC thermograms. The mechanical strength of the γ-glycine crystal was studied with the help of Vickers microhardness instrument. Kurtz-powder NLO study proved the generation of second harmonics (i.e. green light emission) in the grown γ-glycine crystal and its efficiency was calculated as 1.44 times better than that of the reference material potassium dihydrogen phosphate.
PL
Wieloskładnikowe formy stałe leków cieszą się coraz większym zainteresowaniem ze strony przemysłu farmaceutycznego. Główną ich zaletą jest zdolność do zwiększenia biodostępności leku poprzez poprawę jego właściwości fizykochemicznych, w szczególności rozpuszczalności. Poprawienie rozpuszczalności oraz biodostępności, które są kluczowymi czynnikami determinującymi efektywność substancji czynnej jest istotnym wyzwaniem współczesnej farmacji. Przykładem wieloskładnikowych układów są eutektyki, kompozycje koamorficzne i kokryształy, składające się z substancji czynnej oraz drugiego związku (koformera), który wpływa na poprawę jego rozpuszczalności lub innych właściwości tj. stabilność czy właściwości mechaniczne. Jedną z grup leków o słabej rozpuszczalności w wodzie, a co z tym związane niskiej biodostępności są antagonisty receptora angiotensyny II, które stosowane są w leczeniu nadciśnienia tętniczego. W ostatnich latach podjęto kilka prób połączenia tych związków z innymi cząsteczkami, w celu uzyskania układów o zwiększonej rozpuszczalności. Niniejszy przegląd pokazuje, że przedstawiona strategia jest obiecująca, ponieważ prowadzi do otrzymania kompozycji wieloskładnikowych, które stanowią drogę do otrzymania leków o wielotorowym działaniu.
EN
Multi-ingredient solid forms of drugs are becoming more and more popular in pharmaceutical industry. It is because of their high potential to improve bioavailability of a simple drug by improving its physicochemical properties, mainly solubility. Improvement of the solubility and bioavailability, which are key factors determining drug effectiveness, is an important challenge for modern pharmacy. Examples of multi-component systems are eutectic drugs, co-amorphic compositions and cocrystals, consisting of an active substance and a second compound (coformer), which improves solubility or other properties of the active substance. One of the poorly water-soluble group of drugs are angiotensin II receptor blockers used to treat hypertension. In recent years, several attempts have been made to combine these drugs with other molecules to obtain systems with the enhanced solubility. This review shows that the presented strategy is promising because it leads to multi - component compositions, which are the way to obtain drugs of multidirectional effects.
EN
Nuclear energy is considered as one of the most important energy resources in the world. Thorium (Th) has a significant potential to be used in electricity production by nuclear energy since its existence is not depended on the presence of another radioactive elements, and it has larger potential reserves than uranium. Bastnaesite ((Ce, La)CO3F) is one of the minerals from which Th can be economically extracted. In this study, solubility of bastnaesite containing ore obtained from Eskisehir, Turkey was investigated by leaching with H2SO4 and HNO3 in terms of leaching performance of thorium and some rare-earth elements (Ce, Nd, La). In this context, representative samples were taken from three different areas in Eskisehir-Kizilcaoren region, and a composite sample was prepared to be used for the leaching experiments. The effects of several parameters such as the solid ratio, leaching time, acid amount and pulp temperature, on dissolution efficiencies of Th, Nd, Ce and La was investigated. The best results were obtained using 3.42 mol/dm3 HNO3, solid–to–liquid ratio of 35%, 120 min leaching time and 60 oC temperature. Under these optimum conditions, the dissolution efficiencies of Th, Ce, Nd, and La were obtained as 94%, 82%, 77% and 70%, respectively.
EN
The influence of magnesium sulfate as an additive in the nucleation of α and γ-polymorphs of glycine crystallized from aqueous solutions has been explored for the first time. Based on crystallization experiments, it was concluded that lower concentration of magnesium sulfate, say less than 2 g/mL, favors α-nucleation sites, whereas the optimized concentration of magnesium sulfate impurity to yield γ-nucleation sites is 2 g/mL and above. The nucleation time span (in days), solubility and pH were measured for α- and γ-nucleation sites in the aqueous solutions doped with magnesium sulfate. The glycine polymorphs α- and γ-single crystals were grown by slow solvent evaporation technique at ambient temperature. Crystal habit of glycine polymorphs was investigated and analyzed using goniometry. The unit cell dimensions and space group of the as-grown crystal were identified by single crystal XRD analysis. Both α- and γ-polymorphs of glycine were characterized structurally by powder XRD studies. The percentage of magnesium present in the grown glycine crystals was estimated by inductively coupled plasma optical emission spectrometry elemental analysis (ICP-OES). The nonlinear optical properties of the γ-glycine crystals were examined by Q-switched high energy Nd:YAG laser. The second harmonic generation output efficiency of the as-grown gamma glycine single crystals was computed to be 1.31 times superior than that of the reference material potassium dihydrogen phosphate (KDP).
EN
The analysis of amyloid structures is much easier recently due to the availability of the solid-state nuclear magnetic resonance technique, which allows the determination of the 3D structure of amyloid forms. The amyloidogenic polypeptide Aβ(1-40) (PDB ID 2M9R, 2M9S) in its soluble form is the object of analysis in this paper. The solubility of this polypeptide is reached due to the presence of a complexed ligand: polyphenol ε-viniferin glucoside. Two forms of complexes available in the PDB were taken for analysis with respect to the presence of a hydrophobic core in the 3D structure of these complexes. The idealized hydrophobic core structure assumed to be accordant with the 3D Gauss function distribution was taken as the pattern. The aim of this analysis is the possible further comparison to the structures of the hydrophobic core present in amyloids. It is shown that the discordant (versus the 3D Gauss function) fragments present in amyloids appear accordant in the discussed complexes.
8
Content available Asfalty naturalne – charakterystyka i zastosowanie
PL
W artykule zostały scharakteryzowane i zilustrowane asfalty naturalne według klasyfikacji ze względu na rozpuszczalność w dwusiarczku węgla. Przegląd asfaltów i źródeł ich pozyskiwania ma na celu usystematyzowanie wiedzy na ten temat pod kątem możliwości zastosowania praktycznego. Przedstawiono przykładowe zastosowania w skali przemysłowej omawiany asfaltów naturalnych ze szczególnym uwzględnieniem ich wykorzystywania w budownictwie drogowym.
EN
The article describes and illustrates natural asphalts according to the classification due to the solubility of carbon disulphide. The review of bitumens and the sources of their acquisition aims to systematize knowledge on this subject in terms of practical application. Exemplary applications on an industrial scale, discussed natural asphalts with particular emphasis on their use in road construction have been presented.
9
Content available Asfalty naturalne – charakterystyka i zastosowanie
PL
W artykule zostały scharakteryzowane i zilustrowane asfalty naturalne według klasyfikacji ze względu na rozpuszczalność w dwusiarczku węgla. Przegląd asfaltów i źródeł ich pozyskiwania ma na celu usystematyzowanie wiedzy na ten temat pod kątem możliwości zastosowania praktycznego. Przedstawiono przykładowe zastosowania w skali przemysłowej omawiany asfaltów naturalnych ze szczególnym uwzględnieniem ich wykorzystywania w budownictwie drogowym.
EN
The article describes and illustrates natural asphalts according to the classification due to the solubility of carbon disulphide. The review of bitumens and the sources of their acquisition aims to systematize knowledge on this subject in terms of practical application. Exemplary applications on an industrial scale, discussed natural asphalts with particular emphasis on their use in road construction have been presented.
EN
Quartz is, in most cases, the major gangue mineral found in the iron ores. Although it can be activated by calcium at strong alkaline pH, quartz nevertheless, reports to the concentrate with Fe when the iron ores contain siderite. It causes a poor concentrate grade and separation between quartz and iron minerals. The effect of siderite on reverse anionic flotation of quartz from hematite was studied in our previous investigations. In this work, the effect of siderite dissolution on the quartz recovery in the froth product and the effect of pH, ions and temperature on siderite dissolution were investigated. Microflotation, PHREEQC simulation, solution chemistry calculation and Fourier transform infrared spectroscopy (FTIR) measurements were conducted. It was observed that the dissolved species of siderite exhibited negative impact on quartz flotation. This influence became weak to some extent by either stripping the dissolved species or shortening dissolution time. Siderite was easily dissolved in the presence of calcium ion under strong alkaline conditions and its solubility increased with increasing the calcium ion concentrate and temperature. When the calcium ion was added as an activator of quartz under strong alkaline conditions (pH>9.96), calcium existed mainly in the CaCO3 precipitation form according to the solubility rule in the presence of siderite. This form could adsorb onto quartz surfaces and further the chemical reaction between starch and quartz was monitored by FTIR measurements. This study provides a further supplement for previous study. A potential strategy is suggested that finding a collector used at low temperature or flotation under neutral (or weak alkaline) medium is helpful to the reverse flotation of iron ores containing siderite.
EN
A modified emulsion polymerisation synthesis route for preparing highly dispersed cationic polystyrene (PS) nanoparticles is reported. The combined use of 2,2′-azobis[2-(2-imidazolin- 2-yl)propane] di-hydrochloride (VA-044) as the initiator and acetone/water as the solvent medium afforded successful synthesis of cationic PS particles as small as 31 nm in diameter. A formation mechanism for the preparation of PS nanoparticles was proposed, whereby the occurrence of rapid acetone diffusion caused spontaneous rupture of emulsion droplets into smaller droplets. Additionally, acetone helped to reduce the surface tension and increase the solubility of styrene, thus inhibiting aggregation and coagulation among the particles. In contrast, VA-044 initiator could effectively regulate the stability of the PS nanoparticles including both the surface charge and size. Other reaction parameters i.e. VA-044 concentration and reaction time were examined to establish the optimum polymerisation conditions.
EN
Thermodynamic principles for the dissolution of gases in ionic liquids (ILs) and the COSMO-SAC model are presented. Extensive experimental data of Henry’s law constants for CO2, N2 and O2 in ionic liquids at temperatures of 280-363 K are compared with numerical predictions to evaluate the accuracy of the COSMO-SAC model. It is found that Henry’s law constants for CO2 are predicted with an average relative deviation of 13%. Both numerical predictions and experimental data reveal that the solubility of carbon dioxide in ILs increases with an increase in the molar mass of ionic liquids, and is visibly more affected by the anion than by the cation. The calculations also show that the highest solubilities are obtained for [Tf2N]ˉ. Thus, the model can be regarded as a useful tool for the screening of ILs that offer the most favourable CO2 solubilities. The predictions of the COSMOSAC model for N2 and O2 in ILs differ from the pertinent experimental data. In its present form the COSMO-SAC model is not suitable for the estimation of N2 and O2 solubilities in ionic liquids.
EN
Measurements of hydrogen solubility in various nitrobenzene-aniline mixtures were conducted in an autoclave reactor with a stirrer and control of temperature. The solubility of hydrogen was measured at 7 different values of temperature (30 °C, 40 °C, 50 °C, 90 °C, 130 °C, 170 °C, 210 °C, respectively), 3 values of stirrer rotation speed (1200 rpm, 1600 rpm, 2000 rpm, respectively) and a range of pressure of 20 ‒ 30 bar. Moreover, pure aniline, pure nitrobenzene and their mixtures with different concentrations were used. In the next step, values of Henry’s constant were calculated. Based on experimental data a dependence of Henry’s constant on temperature for pure aniline and pure nitrobenzene was proposed. Additionally, for each temperature correlations between Henry’s constant and aniline’s concentration in mixture of nitrobenzene-aniline were found.
EN
The present study introduces the application of a binary solvent of ethyl acetate and water for the selective separation of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The effect of temperature and weight percent of ethyl acetate in water on the solubility of RDX and HMX over a temperature range of 273.15 K to 363.15 K and 70.0 wt.% to 100.0 wt.% ethyl acetate in water mixtures were modelled and optimized using a central composite design (CCD) and response surface methodology (RSM) in Minitab (ver. 16) software. Multiple regression analysis and analysis of variance (ANOVA) showed that the predicted results were in good agreement with the experimental data. The enthalpies of dissolution and mixing of the materials were determined experimentally from the solubility data. The experimental results showed that the solubility ratio of RDX to HMX can change 6.53- to 16.55-fold, indicating a much lower solubility of HMX in this binary solvent, for a relatively selective separation of RDX and HMX mixtures. Separation experiments under optimized conditions showed that 98.3% of the RDX impurity in HMX was recovered in the first precipitation with an HMX purity of > 99.5% as characterized by high performance liquid chromatography (HPLC).
PL
Artykuł przedstawia wyniki badań chemicznych i ekotoksykologicznych pięciu gleb pozyskanych z obszaru zanieczyszczonego metalami ciężkimi zlokalizowanego w bezpośrednim sąsiedztwie Huty Miedzi Legnica, jak również wyniki analiz właściwości ich roztworów glebowych. Badania takie powinny stanowić podstawę oceny ryzyka ekologicznego dla terenów zanieczyszczonych. W badaniach uwzględniono także wpływ wybranych dodatków organicznych, powszechnie stosowanych w remediacji, na rozpuszczalność i ekotoksyczność metali ciężkich. Niektóre z dodatków, np. alkaliczny osad ściekowy, spowodowały radykalny wzrost rozpuszczalności miedzi, która bezpośrednio determinowała poziom ryzyka środowiskowego.
EN
The paper presents the results of chemical and ecotoxicological studies carried out with five soils collected from the area contaminated with heavy metals, located in the immediate vicinity of the Copper Smelter-Legnica, as well as the results of analyses focused on the properties of soil solutions. Such research should be considered as basic in environmental risk assessments for contaminated areas. Additionally, organic additives commonly used in remediation were added to soils. The study involved additionally the effects of soils amendment with organic matter, commonly used in soil remediation, on the solubility and ecotoxicity of heavy metals. Some of amendments, in particular alkaline sewage sludge, caused a drastic increase of copper solubility, which was directly associated with the level of environmental risk.
PL
Przedstawiono wpływ stosowania dihydratu wodorofosforanu wapnia oraz diwodorofosforanu amonu na wytwarzanie biomasy oraz nagromadzenie fosforu przez grykę i kukurydzę. Doświadczenie wazonowe prowadzono na średniej glebie płowej o uregulowanym odczynie i bardzo wysokiej zasobności w przyswajalne formy P, K i Mg. Fosforany stosowano w trzech dawkach, na tle wnoszenia do gleb węglanu wapnia lub słomy koniczyny czerwonej. Po wegetacji roślin w glebach analizowano rozpuszczalność związków fosforu za pomocą testów: Yanai, Egnera i Riehma oraz Huaya (P aktywny i P desorbowany). Wprowadzanie do gleby fosforanów wpływało istotnie na przyrost biomasy roślin. Po nawożeniu wodorofosforanem wapnia gleb wapnowanych oraz nawożonych słomą uzyskiwano wyższe plony obu roślin oraz większe nagromadzenie w nich P. Stosowanie fosforanu amonu pod przedplon w warunkach uprawy kukurydzy na glebie nawożonej słomą powodowało obniżenie plonowania oraz zmniejszenie pobrania P przez tę roślinę. Większe ilości fosforu rozpuszczalnego stwierdzano po ekstrakcji gleb roztworem Yanai niż Egnera i Riehma (DL), jednak na obiektach wapnowanych więcej tego składnika odnajdywano w roztworze mleczanu wapnia. W glebach wapnowanych, nawożonych fosforanem amonu stwierdzono mniejsze ilości wszystkich analizowanych form P niż po stosowaniu fosforanu wapnia.
EN
CaHPO₄·2H₂O and NH₄H₂PO₄ were used for fertilizing the CaCO₃ and/or red clover straw-contg. lessive, mediumheavy and fertile soils (P doses 100–200 mg/kg) used for growing maize and buckwheat in pot expts. The fertilization resulted in an increase in plant biomass yield and in P uptake by the plants. The presence of lime and straw resulted in increasing the biomass yield and P uptake. The methods used for detn. of P content (Yanai, Egner-Riehm P active and P desorption after Huay) gave quite different results.
EN
The paper presents the results of a study on the water absorption capacity and solubility of biodegradable starch foams produced with single-screw extruder TS-45 with L/D=12. Two different moulding dies were used: one with a circular hole with the diameter of 3 mm and one with a ring hole with the inner diameter of 5 mm. During the extrusion process, the temperature of the cylinder ranged from 80 to 130°C and the screw speeds applied were: 100 and 130 rpm. For the application of the ring die, it was observed that regardless of the speed of the screw, the use of the raw material of higher moisture content led to the production of materials with higher solubility. As a result, the obtained materials revealed solubility at a level of 40%. The results demonstrate good solubility of the starchy fillers of the packaging, which may indicate their susceptibility to decomposition in the conditions of high ambient humidity. A statistical analysis showed a significant impact of moisture of the raw material on the WSI of starch foams used irrespective of the other parameters of the extrusion-cooking process. The raw material moisture had a significant effect on the water absorption capacity of only TPS foams produced in the ring die at the screw speed of 100 rpm.
18
EN
Purpose: Silicone materials crosslinked during the hydrosilylation reaction are common in dental prosthetics and dentistry. These materials are characterized by a relatively very good properties. However, one of the fundamental problems associated with the use of such polymers is a low resistance to microbial colonization. Numerus fillers with antimicrobial potential have been used experimentally for a decade. Anyway point of concern in this type of work is the use of commercially available materials as the matrix. However, the composition of the matrix for this materials is not clearly known. Therefore, the aim of this study was to obtain a two-component silicone material, crosslinking at room temperature, with properties corresponding to the needs of dental prosthetics, in particular as denture soft linings. Such material would be a starting point to obtain more sophisticated compositions, however, of known composition in full. Design/methodology/approach: As the matrix the mixtures of polymers were prepared. As the “catalyst” component a vinyl polydimethylsiloxane with platinum catalyst in xylene was prepared. As the “base” component a mixture of vinyl polydimethylsiloxane with methylhydrosiloxane - dimethylsiloxane copolymer was made. One of the two fillers differing in the functionalizing was added into prepared substrates (10 or 15% by weight) and ultrasonically homogenized. The Shore A hardness, tensile strength, bond strength to denture base material, water sorption and solubility were investigated. Measurements were made after different aging periods in distilled water at 37±1°C. Findings: The study showed an increase in mechanical properties with increasing concentrations of fillers. The type of filler significantly affects the test results. Increasing the aging time effects on increasing the hardness of materials. Water absorption and solubility were within the desired range. Research limitations/implications: Research limitations/implications The results of the presented research may be generally dependent on technology of fillers introduction into polymers matrix. Practical implications: The results show promising properties of the tested materials. It can be used as starting material for further studies on soft or super soft denture lining and other materials characterized by similar requirements. Originality/value: The method of receiving silicone - based composites with properties required for the selected prosthetic materials, especially denture soft linings was presented. Their properties were similar to commercially available products.
19
EN
An overview is presented on the interaction of substitutional solutes with carbon and nitrogen in α iron, which is an important factor in controlling the properties of steels. Starting from a simple model of trapping of the interstitial solute atoms by substitutional solute atoms, the principles of experimental methods for quantitative studies are described, focussing on the Snoek relaxation and solubility measurements, and the knowledge acquired by such experiments is reviewed. An account of recent theoretical approaches to the interaction is also given.
PL
Przedstawiono przegląd oddziaływań atomów substytucyjnych z atomami węgla i azotu w żelazie alfa, które jest ważnym czynnikiem wpływającym na właściwości stali. Zaczynając od prostego modelu pułapkowania rozpuszczonych atomów międzywęzłowych przez atomy substytucyjne, przedstawione są zasady metod eksperymentalnych stosowanych w badaniach ilościowych, koncentrując się głównie na badaniach relaksacji Snoeka i pomiarach rozpuszczalności. Przedstawiono przegląd wiedzy nabytej w takich eksperymentach oraz najnowszej próby teoretycznego opisu ww oddziaływań.
PL
Dokonano oceny przydatności produktów porafinacyjnych oleju rzepakowego i biochemicznych metod ich przetwarzania do otrzymania ekologicznych dodatków smarnych. W wyniku przeprowadzonych badań stwierdzono, że: · w syntetycznym oleju estrowym PRIOLUBE żaden z otrzymanych produktów nie wykazywał wystarczającej efektywności smarnej, · w szlamach pohydratacyjnych z powodu dużej zawartości wody (sprzyja rozwojowi mikroorganizmów) następowało skażenie mikrobiologiczne nawet podczas przechowywania w warunkach chłodniczych, · produkty otrzymane metodami biochemicznymi z tłuszczu kanałowego nie wykazywały wystarczającej efektywności smarnej, · produkty otrzymane w wyniku oddziaływania na surowce porafinacyjne oleju rzepakowego szczepami pleśni Mucor racemosus TB75231W nie wykazywały wystarczającej efektywności smarnej.
EN
The opinions of the usefulness of the post-refining products of rapeseed oil and the biochemical methods of the processes to extract ecological lubricating additives were investigated. The results of conducted investigations affirm the following: · None of the received products showed sufficient lubricating efficiency in the synthetic PRIOLUBE ester oil. · Due to the high water content (it promotes the growth of microorganisms) in the sludge of the post-hydrated mixture, even microbial contamination did not occur during storage under refrigeration. · The products obtained from the biochemical fat channel did not show sufficient lubricant performance. · The products obtained as a result of the impact on raw rapeseed oil, which included spent strains of mould Mucor racemosus TB75231W, did not show sufficient lubricant performance.
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