Excess Molar Volume of Binary Systems Containing Mesitylene

This paper presents a review of density measurements for binary systems containing 1,3,5-trimethylbenzene (mesitylene) with a variety of organic compounds at atmospheric pressure. Literature data of the binary systems were divided into nine basic groups by the type of contained organic compound with mesitylene. The excess molar volumes calculated from the experimental density values have been compared with literature data. Densities were measured by a few experimental methods, namely using a pycnometer, a dilatometer or a commercial apparatus. The overview of the experimental data and shape of the excess molar volume curve versus mole fraction is presented in this paper. The excess molar volumes were correlated by Redlich–Kister equation. The standard deviations for fitting of excess molar volume versus mole fraction are compared. Found literature data cover a huge temperature range from (288.15 to 343.15) K

Ekscesni molarni obujam binarnih sustava koji sadrže mezitilen

This paper presents a review of density measurements for binary systems containing 1,3,5-trimethylbenzene (mesitylene) with a variety of organic compounds at atmospheric pressure. Literature data of the binary systems were divided into nine basic groups by the type of contained organic compound with mesitylene. The excess molar volumes calculated from the experimental density values have been compared with literature data. Densities were measured by a few experimental methods, namely using a pycnometer, a dilatometer or a commercial apparatus. The overview of the experimental data and shape of the excess molar volume curve versus mole fraction is presented in this paper. The excess molar volumes were correlated by Redlich–Kister equation. The standard deviations for fitting of excess molar volume versus mole fraction are compared. Found literature data cover a huge temperature range from (288.15 to 343.15) K.U ovom je radu dan pregled izmjerenih gustoća binarnih sustava koji sadre 1,3,5-trimetilben-zen (mezitilen) s različitim organskim spojevima pri atmosferskom tlaku. Literaturni podaci o binarnim sustavima razvrstani su u devet osnovnih skupina prema vrsti organskog spoja u smjesi s mezitilenom. Ekscesni molarni obujmi izračunati su iz eksperimentalno određenih vrijednosti gustoće i uspoređeni s literaturnim podacima. Gustoće su izmjerene pomoću nekoliko eksperimentalnih metoda: piknometrom, dilatometrom ili nekom od komercijalnih aparatura. Prikazani su eksperimentalni podaci i oblik krivulje ekscesnog molarnog obujma u ovisnosti o molnom udjelu. Procijenjene vrijednosti ekscesnih molarnih obujama u ovisnosti o molnom udjelu korelirane su Redlich-Kisterovom jednadžbom, a prikladnost odabrane funkcije izražena je usporedbom standardnih devijacija. Literaturni podaci pokrivaju široko temperaturno područje (od 288,15 do 343,15 K).</p

Comparison of Hexane Vapour Permeation in Two Different Polymeric Membranes via an Innovative In-line FID Detection Method

This manuscript presents a novel method for the analysis of vapour permeation through polymeric membranes based on in-line analysis of the permeate with an FID detector. The hexane vapour permeation was studied for two commercially available membranes, namely low-density polyethylene (LDPE) and thin-film-composite polyamide (PA) membrane. The hexane permeation was studied at temperatures of 25–45 °C, hexane vapour activity in the range of 0.2–0.8 and trans-membrane pressures of 5–50 kPa. Two fundamentally different membranes were chosen to demonstrate the potential and sensitivity of the permeation apparatus. Upon increasing the temperature from 25 to 45 °C, the flux in LDPE was found to increase almost fourfold over the whole activity range. The nonlinear increase of the flux with activity indicates plasticization of the polymer by hexane. Contrarily, the flux in the PA membrane increases almost linearly with activity, with only a minor upward curvature. Since the PA is far away from any phase transition, it is less temperature-dependent than LDPE. The activation energy for permeation demonstrates that the temperature dependence in the LDPE membrane is dominated by changes in diffusion, whereas it is dominated by changes in solubility in the PA membrane. This work is licensed under a Creative Commons Attribution 4.0 International License

Extremální úlohy řešené v programu GeoGebra

The solving of applied problems is a reasonable way to gain better understanding of mathematical concepts, especially for future engineers. GeoGebra is a very useful tool for modeling these problems thanks to its interactivity.Rešení aplikovaných úloh je jeden z vhodných zpusobu pro lepší pochopení matematických konceptu predevším pro budoucí inženýry. Díky své interaktivite je GeoGebra velmi užitecný nástroj pro modelování takových úloh