Wyniki wyszukiwania - Biblioteka Nauki

1

Polyassociative Model of A2B6 Semiconductor Melt and p-T-x Phase Equilibria in Zn-Cd-Te System

100%

Moskvin P. , Antonov M. , Olchowik G. , Olchowik J. , Zdyb A. , Gulkowski S. , Sadowski W.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2011

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tom Vol. 15, No 1

121-130

EN

This work presents a numerical analysis of p-T-x phase equilibrium in the Zn-Cd-Te ternary system in the framework of the polyassociative solution model. On the basis of the experimental data on p-T-x phase equilibrium in the ternary system, thermodynamic functions describing the formation of liquid associates were found. It was shown that the results of the mixing of components in the Zn-Cd-Te ternary melt are related to the occurrence of ZnCdTe and ZnCdTe3 associates. Dissociation parameters of these complexes were calculated and subsequently used in order to efficiently describe p-T-x phase equilibrium of the system in a wide temperature range.

2

New Approach to the Determination of Phase Equilibrium in the Zn-Te System

100%

Moskvin P. , Olchowik J. , Olchowik G. , Zdyb A. , Gulkowski S. , Sadowski W.

TASK Quarterly : scientific bulletin of Academic Computer Centre in Gdansk

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2011

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tom Vol. 15, No 2

209-217

EN

The polyassociative model of the liquid phase was applied to describe the phase equilibrium in the Zn-Te system. The thermodynamic functions describing the formation of liquid associates were obtained, taking into account the experimental data on the p-T-x equilibrium in the system. The model of polyassociative solutions with the parameters obtained in this work satisfactorily describes the p-T-x diagram of the system. The numerical results of the analysis of the phase equilibrium confirmed the possibility of applying the polyassociative model to the Zn-Te system in a wide temperature range.

3

Regression analysis of the salts solubility of the NaCl - NaHCO3 - H2O, NH4HCO3 - NaHCO3 - H2O and NH4HCO3 - NH4Cl - H2O systems

100%

Sytniewski A.

Polish Journal of Applied Chemistry

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1998

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tom Vol. 42, nr 1

23-29

EN

The regression analysis of the literature data of salts solubility in three ternary systems mentioned in the title of the paper has been done. Results have been presented in the form of equations of the salts solubility and in the phase equilibrium plots.

4

Computer modelling of pentoxifylline release from a cylinder-shaped hydroxylapatite carrier

100%

Mietła A. , Mycek B. , Wanat I. , Wąs J. , Zima A.

Bio-Algorithms and Med-Systems

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2012

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tom Vol. 8, no. 1

89--109

EN

The main objective of this article is to present the basic stages of creating a computer simulation of medication release from an undegraded carrier. Additionally, an innovative approach was presented to the construction of a porous material used for making the carrier for the medication. The programme presented here is based on Cellular Automata, used as a tool for modelling physical, chemical and biological phenomena which change in time. The results of in-silico calculations have been compared with empirical results.

5

THE INFLUENCE OF THE PHYSICOCHEMICAL FACTORS ON DISSOLUTION OF THE SUBSTANCE OF CLASS II BCS FROM SOLID DISPERSIONS WITH CHITOSAN

100%

Grimling B. , Górniak A. , Meler J. , Pluta J.

Progress on Chemistry and Application of Chitin and its Derivatives

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2013

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tom 18

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nr 18

157-165

EN

The BCS class II includes drugs with low solubility and high permeability. Fenofibrate is an example of this class drugs. The aim of the study was to investigate the effect of chitosan about average molecular weight in various formulations on the dissolution of fenofibrate incorporated into this polymer carrier. The study investigated fenofibrate in solid dispersions using a method of the solvent evaporations at the drug to polymer ratio of 1:9;3:7;5:5. The highest dissolution of fenofibrate, amounting to 72.7%, was observed after 60 minutes from solid dispersions with drug-polymer weight ratio 1:9 in the presence chitosan A and was72 times higher in relation to the amount of added polymer in comparison to the solubility of pure drug. Investigations DSC showed that fenofibrate was remained in crystalline state in solid dispersion.

6

High Pressure Vapour-Liquid Equilibrium of Volatiles in Supercritical Carbon Dioxide

100%

Gurgenova K. , Bogeł-Łukasik R. , Wawrzyniak P.

Chemical and Process Engineering

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2013

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tom 34

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nr 3

387-392

EN

Binary vapour-liquid equilibrium of thymoquinone and carbon dioxide at the isothermal conditions was carried out at temperature 323.15 K and pressures from 6 to 10 MPa. The experimental data were fitted to the Soave-Redlich-Kwong equation of state. Results could be used for selection of process parameters in separation of volatiles from raw oil or for evaluation of existing separation technologies.

7

Models of the Hydrophobic Attraction

100%

Widom B.

Polish Journal of Chemistry

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2001

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tom Vol. 75, nr 4

507-515

EN

Some recently proposed models of hydrophobic attraction, equivalent to the Ising model of ferromagnetism, are described and their properties reviewed. They are such that the accommodation of a hydrophobic solute in the solvent is energetically favorable but even more unfavorable entropically, which is believed to be the basic mechanism of hydrophobicity in water solution. The effective attraction between pairs of solute molecules as mediated by the solvent is calculated, as is the deviation from additivity in the interactions among three or more. The very low solubilities of the solutes in the model solvents are also calculated. In a different model, based on a phenomenological free energy leading to a closed-loop solubility curve in the temperature-composition plane, one finds the same very great increase in heat capacity on dissolving a hydrophobic solute as is found in experiment.

8

Solubility of a pharmacological intermediate drug Isatin in different solvents at various temperatures

100%

Baluja S. , Bhalodia R. , Bhatt M. , Vekariya N. , Gajera R.

International Letters of Chemistry, Physics and Astronomy

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2013

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tom Vol. 12

36--46

EN

The solubility of isatin in different solvents was studied by a gravimetrical method from (298.15 to 318.15) K under atmospheric pressure and the solubility data were correlated against temperature. The solvents selected for the present study are: water, methanol, ethanol, 1-butanol, dichloromethane, dichloroethane, chloroform and carbon tetra chloride. Among chlorinated solvents, solubility is observed to be maximum in 1, 2-dichloroethane and minimum in dichloromethane whereas in alcohols, maximum solubility is observed in methanol. In water, solubility is found to be minimum. Further, some thermodynamic parameters such as Gibb’s energy (ΔGsol), heat of solution (ΔHsol) and entropy of solution (ΔSsol) have also been evaluated.

9

Comparison of the structure of Aβ(1-40) amyloid with the one in complex with polyphenol ε-viniferin glucoside (EVG)

100%

Dułak D. , Banach M. , Wiśniowski Z. , Konieczny L. , Roterman I.

Bio-Algorithms and Med-Systems

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2018

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tom Vol. 14, no. 2

art. no. 20180008

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.

10

High Pressure Vapour-Liquid Equilibrium of Volatiles in Supercritical Carbon Dioxide

88%

Gurgenova K. , Bogeł-Łukasik R. , Wawrzyniak P.

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2013

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nr 3

11

Synthesis and evaluation of thermodynamic solubility of triazolo quinolone class derivatives in various solvents at 298.15-328.15 K

88%

Baluja S. , Pithiya M. , Lava D.

World Scientific News

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2021

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tom 151

16-30

EN

The solubility of triazolo quinolone class derivatives in methanol, ethanol, n-propanol, n-butanol and ethyl acetate was measured using a gravimetrical method at temperature ranging from 298.15 K to 328.15 K. The results of these measurements were correlated with semi empirical equations. Some thermodynamic parameters such as dissolution enthalpy, Gibb’s free energy and entropy of mixing have also been calculated.

12

Solubility of Eskisehir thorium/rare earth ores in sulphuric and nitric acids

88%

Kursun I. , Tombal T. D. , Terzi M.

Physicochemical Problems of Mineral Processing

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2018

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tom Vol. 54, iss. 2

476--483

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.

13

Amfifil'nye proizvodnye poli-N-vinilpirrolidona povedenie v vodnych rastvorach

88%

Sharipova E. I. , Malih E. V. , Kuskov A. N. , Villemson A. L. , Larionova N. I. , Shtilman M. I. , Torchilin V. P.

Prace Naukowe Instytutu Technologii Organicznej i Tworzyw Sztucznych Politechniki Wrocławskiej. Konferencje

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2001

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tom Vol. 50, nr 23

437-437

14

Influence of complexation on the composition of equilibrium phases in the system of Ce2(SO4)3-La2(SO4)3

88%

Milanova M. , Todorovsky D. , Balarew C. , Minkova N. , Ivanova K.

Open Chemistry

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2007

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tom 5

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nr 1

13-19

EN

The cocrystallization of Ce2(SO4)3 and La2(SO4)3 is studied in aqueous and H2SO4 (150 g/dm3) solutions at 25 °C and 64 °C. The effect of the formation of inner sphere sulfate complexes of the type LnSO 4+ in determining the composition of the equilibrium phases is revealed. [...]

15

Statistical Optimization and Selective Separation of RDX and HMX Explosives by Using Binary Solvent Mixtures Containing Ethyl Acetate and Water

88%

Damiri S. , Pouretedal H. R. , Panahi H. , Dris A.

Central European Journal of Energetic Materials

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2017

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tom Vol. 14, no. 2

391--402

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).

16

Effects of Short-chain Alcohols on the Phase Behavior, Solubilities and Solubilization Ability in Microemulsion Systems

88%

Xia Y. , Li H. L. , Chai J. L. , Yu X. Y. , Liu J. , Qin C. K. , Chen J. F.

Polish Journal of Chemistry

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2009

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tom Vol. 83, nr 2

315-324

EN

The effects of short-chain alcohols on the phase behavior, solubilities and solubilization ability in the microemulsion systems cetyltrimethyl ammonium bromide (CTAB) or cetylpyridinium bromide (CPB) or 1-hexadecyl-3-methylimidazolium bromide (C16mimBr)/1-propanol or 1-butanol or 1-pentanol/n-octane/brine were investigated with the d-g fishlike phase diagram. The phase diagram was affected greatly by alcohols, and the magnitude of the middle phase region in the fish body is in the order 1-propanol greated than greated than 1-butanol greated than1-pentanol. With the carbon chain length becoming shorter, more alcohol molecules are needed to balance the interfacial layer. Nearly all surfactants enter into the interfacial layer and little remains in aqueous or oleic phase. However, alcohols dissolve in the aqueous and oleic phases, besides they enter into the interfacial layer. The solubilization ability of the microemulsion system is mainly affected by the alcohols and the order is 1-pentanol greated than 1-butanol greated than 1-propanol.

17

Zmiany rozpuszczalności wybranych związków fosforu oraz ich wykorzystanie przez rośliny

88%

Piszcz U. , Spiak Z.

Przemysł Chemiczny

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2016

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tom T. 95, nr 6

1221--1224

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.

18

Microstructure and surface free energy of light-cured dental composites after their modification with liquid rubber

88%

Sowa M. , Przekora A. , Pałka K.

Engineering of Biomaterials

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2022

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tom vol. 25, no. 164

9--15

EN

The use of liquid rubber as a component of light-cured dental composites is one of the methods of increasing their fracture toughness. It also reduces polymerization shrinkage and offers the potential to lower water sorption. The aim of the study was to evaluate the miscibility of liquid rubber in composite matrix resins as well as changes in the wettability and surface free energy (SFE) values of commercial lightcuring composites after their modification with liquid rubber. The research materials were Flow Art and Boston (Arkona) light-cured composites and resin mixtures used in their production. Liquid rubber Hypro 2000X168LC VTB (Huntsman Int.) was used as a modifier. The solubility of liquid rubber was assessed under light microscopy. The contact angle and SFE measurements were made on a DSA30 goniometer (Kruss) using water and diiodomethane. It was found that the liquid rubber solubility depended mainly on the viscosity of the resin, which was related to the amount of BisGMA. The resulting mixture showed good temporal stability without larger domains. The curing process released the liquid rubber as a separate phase formed as spherical domains. The morphology of these domains was homogeneous and their size did not exceed 50 µm in diameter. The presence of liquid rubber in modified composites increased their hydrophobicity and reduced the surface free energy value. The obtained properties might help to reduce the formation of bacterial biofilm on dental fillings.

19

Liquid Perfluorochemicals as Flexible and Efficient Gas Carriers Applied in Bioprocess Engineering: An Updated Overview and Future Prospects

88%

Pilarek M.

Chemical and Process Engineering

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2014

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tom 35

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nr 4

463-487

EN

Fully synthetic, biochemically inert and water-immiscible liquid perfluorochemicals (PFCs) are recognised as flexible liquid carriers/scavengers of gaseous compounds (respiratory gases mainly, i.e. O2 and CO2) and increasingly applied in bioprocess engineering. A range of unmatched physicochemical properties of liquid PFCs, i.e. outstanding chemo- and thermostability, extremely low surface tension, simultaneous hydro- and lipophobicity, which result from carbon chain substitution with fluorine atoms (the most electronegative chemical element) and the presence of intramolecular C-F bonds (the strongest single bond known in organic chemistry) have been described in detail. Exceptional propensity to solubility of respiratory gases in liquid perfluorinated compounds has been widely discussed. Advantages and disadvantages of bioprocess applications of liquid PFCs in the form of a pure PFC as well as in an emulsified form have been pointed out. A liquid PFC-mediated mass transfer intensification in various types of microbial, plant cell and animal cell culture systems: from miniaturised microlitre-scale cultures, via biomaterial-based scaffolds containing culture systems, to litre-scale bioreactors, has been reviewed and elaborated on bearing in mind the benefits of bioprocesses.

20

A Study of the Solubility of Biodegradable Foams of Thermoplastic Starch

88%

Mitrus M. , Combrzyński M. , Kupryaniuk K. , Wójtowicz A. , Oniszczuk T. , Kręcisz M. , Matysiak A. , Smurzyńska A. , Mościcki L.

Journal of Ecological Engineering

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2016

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tom Vol. 17, nr 4

184--189

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.