Wilson Model Research Articles

A model of planned and unplanned information-seeking behaviour

The main purpose of this article is to present a model for information-seeking behaviour with an emphasis on unplanned and planned behaviour of users in using library resources and services. The working method was that, reviewing the literature and previous information behaviour models, such as Wilson, Ellis, Kuhlthau, and Dervin models, this article proposes a novel model of information-seeking behaviour for library users. Our model of information-seeking behaviour was developed by combining the existing models of planned information-seeking behaviour with the focus on the factors affecting unplanned rather than planned behaviour of users in accessing resources or services. Our proposed model for information-seeking behaviour of clients has two main parts. The first part planned behaviour resulting from a problem or a certain information need according to which the user seeks to find information in a planned manner. The second part deals with unplanned behaviour shaped by a hidden or uncertain information need. Finally, both types of behaviour can result in the discovery, extraction, collection and use of information.

PENGEMBANGAN INSTRUMEN LITERASI NUMERASI KONTEKS SOSIAL BUDAYA DI SMK PLUS PAKUHAJI

This study aims to produce a Vocational Mathematics numeracy literacy instrument that has been tested for validity and reliability, as well as through a systematic analysis of the instrument using a test of discrimination and index of difficulty. This type of research is development research with the Wilson model and the Oriondo and Antonio models. Methods of data collection using interviews, expert validation sheets, questionnaires and numeracy literacy tests. Data were analyzed descriptively and quantitatively. The research results obtained were: 1) the expert's assessment stated that this numeracy literacy instrument was an appropriate instrument to use; 2) the readability test shows that this numeracy literacy instrument is in the "good" category, 3) the validity test shows that this instrument is valid; 4) this numeracy literacy instrument is a reliable instrument with a reliability value of ????????>????????????????????????; 5) has a good interpretation of discriminating power with conclusions that can be used without revision; 6) Average item difficulty index. So that the resulting instrument is a feasible instrument used to measure students' numeracy literacy

Equilibrium solubility, solvent effect, equation correlation, and thermodynamic properties of cyclododecanone in twelve organic solvents

The solubility of cyclododecanone (CDON) was determined in twelve solvents containing acetonitrile, acetone, toluene, ethyl acetate, cyclohexane, 1,2-dichloroethane, methanol, ethanol, n-propanol, i-propanol, n-butanol and i-butanol. The temperature range for the remaining solvents used in the experiment was 278.15–313.15 K, except for cyclohexane (283.15–313.15 K). The CDON solubility in solvents measured increased with growing temperature. The CDON solubility varies considerably in different solvents. Among the single solvents selected, CDON was most soluble in 1,2-dichloroethane and least in acetonitrile. The solubility in 1,2-dichloroethane is about 2–3 times higher than in acetonitrile. The carbonyl oxygen of CDON readily combines with alcoholic solvents to form hydrogen bonds. Hansen solubility parameters (HSP) and the physiochemical properties of the solvents explain the solvent effect in diverse solvents. To understand CDON dissolution, the electrostatic potential energy surfaces of CDON and the solute–solvent interactions were analyzed at the molecular level on the basis of density functional theory (DFT). Analysis of solvation effects revealed that variations in the CDON dissolution are influenced by a combination of factors rather than a single one. In addition, the Van't Hoff equation, modified Apelblat equation, Yaws equation, λh equation, Wilson model and Jouyban model were utilized to correlate the experimentally obtained value. The computational data show that the ARD (0.88%) and RMSD (0.24%) of Wilson model are the smallest among the selected equations with the best correlation. The apparent thermodynamic properties of CDON dissolution were further accounted for Van't Hoff equation, and the CDON dissolution was observed to be endothermic and entropy-driven.

Experimental solubility of aripiprazole in supercritical carbon dioxide and modeling

The solubility of compounds in supercritical carbon dioxide (SC-{mathrm{CO}}_{2}) has found crucial significance in the fabrication of micro/nano-scaled drugs. In this research, the solubility of Aripiprazole was measured in SC-{mathrm{CO}}_{2} at various temperatures (308–338 K) and pressures (12–30 MPa). Moreover, the experimental solubility results were correlated with several semi-empirical models (Chrastil, Bartle et al., Kumar & Johnston, Menden-Santiago & Teja, Sodeifian et al., and Jouyban et al.) as well as the modified Wilson model. The molar fraction of the drug in SC-{mathrm{CO}}_{2} varied in the range of 1.830times {10}^{-6} to 1.036times {10}^{-5}. The solubility highly depended on the operating pressure and temperature. The Chrastil (0.994), Jouyban et al. (0.993) and Sodeifian et al. (0.992) models showed the highest consistency with the obtained values. Furthermore, self-consistency tests were performed on the solubility of Aripiprazole in SC-{mathrm{CO}}_{2}. The approximate total enthalpy ({mathrm{Delta H}}_{mathrm{total}}), vaporization enthalpy ({mathrm{Delta H}}_{mathrm{vap}}), and solubility enthalpy ({mathrm{Delta H}}_{mathrm{sol}}) were also calculated.

Impact of chronic kidney disease on everyday life: A descriptive qualitative study.

Living with chronic kidney disease is stressful as the disease and its treatments impact on everyday physical, psychological, and social activities. As this disease has a long trajectory, it is important to understand everyday life experiences of those at different points along this trajectory. To explore the impact of chronic kidney disease and its treatment on everyday life. Descriptive qualitative design PARTICIPANTS: Twenty-five adults with chronic kidney disease across various grades were purposively recruited. Data were collected using semistructured interviews. Deductive content analysis informed by the revised Wilson and Cleary model was used to analyse data. There were four themes. Theme 1, experiencing deterioration of kidney function, reflected the physical and psychological problems experienced by participants. Theme 2, changes that happened to me and my family, explained the subsequent limitations in their physical, social and role functioning. Theme 3, responding to a new normal, identified adjustments needed in everyday life to cope with the disease and its treatments. The final theme, thinking ahead and making a decision, captured the future plans and decisions needed while living with chronic kidney disease. People with chronic kidney disease experience complex challenges such as greater symptom burden and functional limitations across the disease grades which impact on their everyday life. Nurses' recognition of these challenges is crucial for identifying and addressing unmet needs. Early individualised interventions, such as routine symptom assessment and management strategies that improve the wellbeing of people are needed.

Quality of life in heterosexual menopausal women: The indirect effect of sexual and marital satisfaction, menopause representations, and psychological morbidity

Menopause may negatively impact Quality of Life (QoL). Our study used a cross-sectional design and research participants were 99 women in natural menopause. In our study, we analyzed the relationship between age at menopause onset, hormone therapy use, duration of couple relationship, menopause duration, psychological morbidity, marital satisfaction, menopause representations, and QoL following the Wilson and Cleary Health-Related QoL conceptual model. The authors found that negative representations, lower marital satisfaction, psychological morbidity, and shorter duration of menopause contributed to lower QoL. Moreover, the authors found that psychological morbidity and menopause representations (identity and control/cure dimensions) had an indirect effect between marital satisfaction and vasomotor, psychosocial, and sexual QoL. Also, we found that age at the onset of menopause showed a moderating effect in the final model. Future studies should replicate these results in a longitudinal design and analyze how the variables that showed a moderating role and indirect effects will function as moderators and mediators, respectively, over time.

Solid-liquid phase equilibrium and thermodynamic properties analysis of Bazedoxifene acetate in fifteen kinds of mono-solvents

Crystallization is widely used for the isolation and purification of active pharmaceutical ingredients (APIs) in the final manufacturing stage. Bazedoxifene (BZD) acetate, classified as a third-generation selective estrogen receptor modulator, is employed in the treatment of postmenopausal osteoporosis. This work reports the equilibrium solubility data of BZD acetate in fifteen different mono-solvents, including methanol, ethanol, n-propanol, i-propanol, n-butanol, ethyl formate, methyl acetate, ethyl acetate, acetone, 2-butanone, cyclohexanone, tetrahydrofuran (THF), 2-methyltetrahydrofurane (2-MeTHF), 1,4-dioxane and acetonitrile (ACN), within the temperature range “T = 283.15–323.15 K” under p = 0.1 MPa. The solubilities of BZD acetate in various solvents increase with increasing temperature. Among the alcoholic solvents, the solubility order is as follows: methanol > ethanol > n-propanol > n-butanol > i-propanol. In esters solvent, the solubility of BZD acetate decreases in the following order: methyl acetate > ethyl acetate > ethyl formate. For ketones solvent, the solubility decreases in the following order: cyclohexanone > acetone > 2-butanone. The maximum value of BZD acetate solubility was 0.011 mol·mol−1 in tetrahydrofuran at T = 323.15 K, but the least data was found in ethyl formate at 283.15 K. Four thermodynamic models, i.e., the Yaws model, modified Apelblat model, λh model, and Wilson model were applied to fit the solubility data of BZD acetate in different solvents. Among them, the Wilson model represents the most accurate fitting outcomes. Finally, the thermodynamic functions of mixing (including enthalpy, entropy, and Gibbs energy) were calculated, and the results indicate a mixing process that is both spontaneous and driven by entropy. The solubility data, correlated models, and derived thermodynamic functions present essential thermodynamic fundamentals for the industrial production of BZD acetate crystallization, facilitating efficient separation and purification.

Estimation of excess Gibbs free energy of multicomponent biofuel mixtures of Butan-1-ol using machine learning methods based on modified Raoults law models

In biofuels, the excess Gibbs free energy of mixing is a very important thermodynamic property as it is used in evaluating the efficiency and sustainability in terms of energy conversion. Multiple biofuel systems containing butan-1-ol were examined with oxygenate ether additives such as MTBE and DIPE using isothermal vapour-liquid equilibrium data at different temperatures (298.15K, 313.15K, 318.15K). Two activity coefficient models, Wilson and van Laar model were compared by determining the bubble pressure and vapor mole fractions of each system using Modified Raoults Law and Machine Learning techniques. Besides, mole fractions and activity coefficients were used to identify the excess property. Results showed that Wilson model is appropriate for all the biofuel systems when using the Artificial Neural Network (ANN) resulting in an MSE of 3.2010e-09, 4.6792e-10, 1.6186e-10, and 5.3461e-07. In addition, van Laar model is more acceptable when Rational Quadratic GPR or Fine Tree algorithm were used with an average RMSE of 0.005820.01 and 0.020950.03 respectively. Lastly, the generated data for both activity coefficient models were also used to estimate the systems excess Gibbs free energy of mixing across varying mole fraction of its components.

Sound Absorption Performance and Mechanism of Aluminum Foams with Double Main Pore‐Porous Cell Wall Structure

To enhance the sound absorption performance of open‐cell aluminum foam, the double main pores‐porous cell walls (DMP‐PCW) aluminum foams via infiltration casting of preforms mixed with two sizes of NaCl particles are prepared. The pore structure, sound absorption performance, and mechanism of DMP‐PCW aluminum foam are investigated. The pore structure consists of double‐sized main pores similar to the NaCl particles and the cell wall pores formed by the connections between NaCl particles. It is found that the static flow resistivity of DMP‐PCW aluminum foam reaches an optimum value of 28105 Pa.s m−2 when the volume proportion of small main pores increases, the size of cell wall pores decreases, and the number of cell wall pores per unit main pore surface area (NPPA) increases. At 800–6300 Hz, the average absorption coefficient is 0.89. In addition, the Wilson model predicts the sound absorption properties of DMP‐PCW aluminum foam. The predicted values agree well with the measured values. The finite‐element acoustic simulations and dynamic viscous‐thermal permeability calculations reveal that the improved sound absorption performance of DMP‐PCW aluminum foam is correlated to the enhanced sound transmission caused by increased NPPA and increased viscous‐thermal loss due to the double main pore structure.

Students’ Information Seeking Behavior and Information Needs

"All around the world, universities and university libraries have faced the decline in the importance as a physical entity. This decline has multiple causes, such as the change of users' expectations and needs, the universities switch from exclusively on-site work and teaching to remote or more flexible schedules, the availability of alternative sources of information, the use of new technologies (social networks, mobile technologies), the preference for anytime and remote access from personal devices, the demand for greater compatibility and interoperability of systems, and the transformation of library user from consumer into content creator. Thus, this research aims to study the information-seeking behavior of college students in the context of traditional and electronic resources). Urquhart and Rowley's model of information-seeking behavior will be applied along with Wilson's model, to identify the factors that influence information-seeking behavior: the design of information resources, the educational infrastructure, the organizational culture, the availability and access constraints, the information culture, the search strategy, the support and training, the pedagogy, the behavior of teachers regarding information, and the study discipline and curriculum. Nonetheless, the article will explore information literacy skills and the barriers to accessing and using them: cultural aspects related to teaching and learning styles, language proficiency and digital culture. Methods. Initial stages of the project assess the current level of inclusion of industrial property topics into higher education curricula and labour market needs. Samples include Slovenian technical sciences faculties, and employers of technical profiles with needs for industrial property knowledge. Online surveys are used for data collection. Results. General, not positive, alignment was found in terms of expected competencies: Companies do not place high priorities on industrial property competencies of their non-law employees. Furthermore, many higher education institutions do not include these topics in their teaching. Industrial property teaching is needed, but not done, which implies the need for educators-employers dialogue. A relatively traditional image of libraries emerges, as they are usually not involved in teaching. This provides an excellent opportunity for libraries to evolve and become more proactive. Conclusions. Our findings offer a valuable contribution to the planning of a systematic and holistic intellectual property curriculum for technical studies within the European Union."

Student information-seeking behavior in meeting Islamic information needs

The large number of Islamic tertiary institutions with a specific religious curriculum between one Islamic university and another. This curriculum is should be able to increase students’ knowledge of Islamic information for academic and non-academic needs. So, this study aimed to describe the behavior of Islamic students in Malang City using the Wilson model, including patterns of information-seeking behavior, sources used in seeking information, and evaluation of Islamic information. Method research was a qualitative study. Research subject involving nine informants consisting of students from UIN Maulana Malik Ibrahim, the Islamic University of Malang, and the University of Muhammadiyah Malang. This study described Islamic information-seeking behavior based on cognitive, affective, and physiological information needs. In addition, this study described information search patterns such as passive search, active search, and continuous search. This study concludes that students in seek Islamic information used diverse pattern. Information for academic purposes, primarily via books, scientific journal databases, and Google Scholar, and Islamic information to meet non-academic needs comes from YouTube, Instagram, and websites. Students can notice the information creator's background in examining online sources of information. Students evaluate Islamic information sources by comparing various sources obtained, asking friends who are considered qualified in religious knowledge, and directly asking the ustadz.

Determination and Simulation of the Solubility of Bifonazole in 14 Pure Solvents at 283.15–323.15 K

Bifonazole is a derivative of imidazoles with a wide antibacterial spectrum and is widely used for treating various fungi infections. However, in the open literature, the solubility data of bifonazole are rarely reported. Considering the importance of the solubility of bifonazole in its manufacture and applications, the solubility of bifonazole in 8 alcohols and 4 n-alkyl acetates as well as acetonitrile and N, N-dimethylformamide in the temperatures ranging from 283.15 to 323.15 K has been measured with the assistance of a dynamic laser solubility monitoring device in this paper. The measured solubility of bifonazole follows the order of DMF > alcohols > esters > acetonitrile. The relationship between the solubility of bifonazole and temperature was correlated using three semi-empirical and two activity coefficient solubility models. In addition, the thermodynamic mixing properties (ΔmixG, ΔmixH, ΔmixS, γ1∞, and H1E, ∞) of the bifonazole solutions were evaluated in terms of experimental data and Wilson model parameters.

Phase Equilibrium and Crystallization Process of the Ternary System KCl-(NH2)2CO-H2O at Different Temperatures

The phase equilibriums of the ternary system KCl-(NH2)2CO-H2O at 303.15 K, 323.15 K, 333.15 K, and 343.15 K were studied using the isothermal dissolution equilibrium method, in which the composition of equilibrium solid phase was determined by Schreinemaker’s wet residue method and X-ray diffraction (XRD) method. It was found that the ternary system is a simple cosaturated system, without the formation of neither double salt nor solid solution. Wilson and NRTL models were employed to correlate in the solubility data of the system at experimental temperatures. The maximum values of RAD and RMSD of the Wilson model were 2.18 × 10−2 and 0.83 and those of the NRTL model were 1.69 × 10−2 and 0.40, respectively. The two models were utilized to forecast solubility data at various temperatures, and the obtained outcomes were in line with the literature data. Based on the experimental solubility data at 343.15 K, the cooling crystallization process of the system was monitored online by focused beam reflectance measurement (FBRM) and particle video microscope (PVM). The crystal products were characterized by XRD, scanning electron microscope (SEM), and energy dispersive spectrometry (EDS). The results showed that the precipitation of (NH2)2CO occurred during the crystallization process, and this was followed by KCl. KCl was formed on the surface of (NH2)2CO crystal. The crystal was a simple mixture containing KCl and (NH2)2CO.

Vapor-liquid equilibria in the 1-methylpyrrolidine + 1-butylimidazole binary system: Experimental measurements and theoretical modelling

In this study, a comprehensive investigation of the 1-methylpyrrolidine + 1-butylimidazole binary system was conducted to establish a valuable foundation for process design. Isobaric binary vapor − liquid equilibrium (VLE) data was measured (80 data points) at 50.0, 20.0, 10.0, and 7.5 kPa using dynamic equilibrium cell (VLE 602) and found that no azeotrope existed throughout the entire operating pressure range. Thermodynamic consistency was validated using the Redlich − Kister area test (9.56801%). The vapor pressure of 1-butylimidazole was determined through direct measurement (12 data points) of the equilibrium temperature at different pressures and the Antoine equation parameters were regressed based on the acquired data. The VLE data were regressed using maximum likelihood (ML) method, and binary interaction parameters (BIP) were estimated for NRTL–HOC, UNIQUAC, Van Laar, and Wilson models. The model validation demonstrated consistency between calculated and experimental values for temperature and mole fraction of the vapor phase. In addition, dipole moment (μ) values were evaluated by quantum chemical calculations using the Hartree–Fock (HF) method through GAMESS package. The density (12 data points), the sound velocity (12 data points), the refractive index (3 data points), and the normal boiling points (3 data points) were also measured for binary mixtures and pure components.

Investigation on solid-liquid equilibrium for binary mixtures of carbon dioxide (R744) and alkanes: Propane (R290) and isobutane (R600a)

The solid-liquid equilibrium (SLE) of binary systems containing carbon dioxide (R744) and alkanes propane (R290) and isobutane (R600a) was experimentally investigated. A novel experimental setup using the cooling curve method was designed, built and verified, enabling SLE measurements at temperatures down to 173 K. The temperature and pressure of the triple point of carbon dioxide (CO2) were measured. The results for R744 and the binary mixture of carbon dioxide and propane were in agreement with the available literature data, demonstrating the accuracy of the experimental setup. Activity coefficients were determined for the binary mixtures studied. The Schröder and Wilson equations were used to calculate solubility over various temperatures and compositions. The Wilson model produced a very accurate correlation for the studied non-ideal binary mixtures, while the Schröder equation did not provide satisfactory results. Determined activity coefficients and SLE curves should be useful for the design of low-temperature refrigeration systems operating on carbon dioxide mixtures with low global warming potential.

Linking the demographic, socio-economic and oral health status to oral health-related quality of life of the sudanese older adults: a cross sectional study

BackgroundOral Health-Related Quality of Life (OHRQoL) is an important measure of patients’ needs and progress. Identifying the links between clinical and non-clinical factors with OHRQoL in a specific population will facilitate the development of effective preventive strategies. The aim of the study was to assess the OHRQoL of Sudanese older adults, and to identify the possible relations between clinical and non-clinical predictors with OHRQoL using Wilson and Cleary model.MethodsThis cross-sectional study was conducted among older adults attending the out-patient clinics in Khartoum State’s Health Care Centers, Sudan. OHRQoL was assessed using the Geriatric Oral Health Assessment Index (GOHAI). Two modifications of Wilson and Cleary’s conceptual model were tested using structural equations modeling including: oral health status, symptom status, perceived difficulty of chewing, oral health perceptions, and OHRQoL.Results249 older adults participated in the study. Their mean age was 68.24 (± 6.7) years. The mean GOHAI score was 53.96 (± 6.31) and trouble biting/chewing was the most commonly reported negative impact. Wilson and Cleary models showed that pain, Perceived Difficulty Chewing (PDC), and Perceived Oral Health had a direct effect on OHRQoL. In model 1, age and gender had direct effects on oral health status, while education had direct effects on OHRQoL. In model 2, poor oral health status is associated indirectly with poor OHRQoL.ConclusionsThe OHRQoL of the studied Sudanese older adults was relatively good. The study partially confirmed Wilson and Cleary model as Oral Health Status was related directly to PDC and indirectly to OHRQoL through functional status.

Solubility determination, model correlation, thermodynamic analysis, molecular dynamic simulation of Favipiravir in twelve pure solvents

The solubility of Favipiravir in twelve pure solvents, including methanol (MeOH), ethanol (EtOH), n-propanol (NPOH), isopropanol (IPOH), n-butanol (NBOH), acetone (DMK), acetonitrile (MeCN), dichloromethane (DCM), N, N-Dimethylformamide (DMF), methyl acetate (MtAC), ethyl acetate (EtAC), butyl acetate (NBAC) was measured by gravimetric method at a temperature range of 293.15 to 333.15 K at 0.1 MPa. The maximum and minimum of Favipiravir solubility were obtained in DMF at 333.15 K (0.02599 mol·mol−1) and MeOH at 293.15 K (0.00147 mol·mol−1), respectively. At 298.15 K, the order of solubility in different solvents is: DMF > NBAC > DMK > MtAC > EtAC > NBOH > DCM > EtOH > NPOH > IPOH > MeCN > MeOH. The Hansen solubility parameter (HSP) was used to analyze the miscibility of Favipiravir in selected solvents. In addition, the solvent effect was studied by analyzing solvent properties, which indicate that the solubility of Favipiravir in selected solvents is influenced by the synergistic effect of multiple factors. The Modified Apelblat model, λh model, NRTL model, and Wilson model were employed to correlate the solubility data, indicating the Apelblat model provides the highest regression accuracy corresponding to the lowest average value of average relative deviation (ARD, 0.017459) and root mean square deviation (RMSD, 0.00012). In order to explain the dissolution behavior of Favipiravir in different solvents, the intermolecular interactions were analyzed by using Hirshfeld surface (HS), Molecular electrostatic potential surface (MEPS), and solvation free energy. The thermodynamic parameters derived from van’t Hoff equation including ΔdisG0 (10.71–16.57 kJ·mol−1), ΔdisH0 (6.33–18.67 kJ·mol−1), and ΔdisS0 (−32.77–25.47 J·mol−1·K−1) indicate that the dissolution of Favipiravir is endothermic, entropy-driven or has no driving force, and non-spontaneous.

Solubility Measurement and Data Correlation of Cyclohexanone, tert-Butanol, and 1,4-Dioxane in p-, o-, and m-Xylenes and Ethylbenzene

The solubility of cyclohexanone, tert-butanol, and 1,4-dioxane in p-, o-, and m-xylenes and ethylbenzene was measured by a gas chromatography method under an atmospheric environment. The measured data indicated that the solubility of cyclohexanone, tert-butanol, and 1,4-dioxane in the xylenes and ethylbenzene increases with increasing temperature. The experimentally determined solubility results were fitted with the modified Apelblat equation, Van’t Hoff equation, and Wilson model. Among them, the Wilson model was most consistent with the measured solubility results. The dissolution-related thermodynamic properties of cyclohexanone, tert-butanol, and 1,4-dioxane in xylenes and ethylbenzene, including the changes of molar Gibbs free energy, molar enthalpy, and molar entropy, were predicted and analyzed via the correlated Wilson model, which indicates that the dissolution behaviors are spontaneous and endothermic process. The obtained solubility results provide the thermodynamic foundation for the development and upgrading of industrial separation processes related to xylene, ethylbenzene, cyclohexanone, tert-butanol, and 1,4-dioxane.

Measurement and correlation of solubility of 2-alkylanthraquinone (ethyl, tert-butyl and tert-amyl) in mixed solvents of 1,3,5-trimethylbenzene and tetrabutylurea

The solubility of 2-ethylanthraquinone (EAQ), 2-tert-butylanthraquinone (TBAQ) and 2-tert-amylanthraquinone (TAAQ) in binary solvents consisted of 1,3,5-trimethylbenzen (TMB) and tetrabutylurea (TBU) was measured by the equilibrium method at the temperature ranging between 303.15 and 323.15 K and 101.1±2 kPa. With raising the temperature and content of TMB in the mixed solvents, the solubility of EAQ, TBAQ and TAAQ increased gradually. At the same content of TMB and temperature the solubility of TAAQ was higher than that of TBAQ, which was in its turn much higher than that of EAQ. The experimental data were correlated by Wilson model, NRTL model and modified λ-h equation, respectively. Among them, Wilson model gave a relatively good accuracy with the average and maximum relative deviation of 0.56% and 1.77% for EAQ, 1.08% and 4.58% for TBAQ, 0.65% and 1.78% for TAAQ. In addition, the solubility of TAAQ in TMB + TBU was predicted by Wilson model, NRTL model and modified λ-h equation, respectively. The Wilson model showed the best reliability, with the average and maximum relative deviation of 0.98% and 3.10%. The calculated enthalpy change, entropy change and Gibbs free energy change of the dissolution process for AQs all were positive, which demonstrates the dissolving process to be endothermic, entropy-driving and non-spontaneous.

Solubility determination and thermodynamics modeling of n-alkyl-parabens in short-chain alcohols from (288.15 to 318.15) K

The well-established preservative and antimicrobial effect of alkyl parabens result in its wide application in the food, cosmetics, and pharmaceutical industries and motivates the solubility data obtaining. In this work, the solubility of parabens (methyl-, ethyl-, propyl-, and butyl-) in short-chain alcohols (ethanol, n-propanol, and 2-propanol) was experimentally determined by the gravimetric method from 288.15 to 318.15 K. Different thermodynamic models (Wilson, NRTL, UNIFAC; and COSMO-SAC models) were applied to correlate the experimental data. In general, the mole fraction of parabens increased with increasing temperature, following the order butyl > propyl > ethyl > methyl parabens in the three investigated solvents. Wilson and NRTL models presented a good correlation, according to the calculated values of mean squared deviation (RMSD) and absolute deviation (AD), while the UNIFAC showed high deviations, which was expected because it is not an adjustable model. The COSMO-SAC model has been compared to experimental data and helped understand the solute–solvent interactions. The sigma profile (σ-profile) of the molecules obtained by COSMO-SAC showed that alkyl parabens have similarities to ethanol, n-propanol, and 2-propanol. Additionally, the solubility of the parabens increased with the chain size due to the increase in their lipophilicity. This fact corroborated with the experimental data obtained. The solubility was also favored with the temperature increasing. Thus, a determination of the solubility of parabens in different solvents was collected to obtain complete physicochemical data, contributing to the projection and expansion of industrial applications of these compounds as excipients in liquid formulations.