scholarly journals Solubility of dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)] in common pure solvents and binary solvents at different temperatures

2019 ◽  
Vol 6 (11) ◽  
pp. 190728
Author(s):  
Jianrong Ren ◽  
Dong Chen ◽  
Yanwu Yu ◽  
Hongzhen Li

The solubility of dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)] (DCBNT) was first measured under the different pure solvents and binary solvents by the dynamic method over the temperature range of 290–360 K at atmospheric pressure. Results in all the solvents were positively correlated with temperature, namely increased with increasing temperature. The experiment data were correlated by the Apelblat equation, the Yaws equation and the polynomial equation. The conclusion showed that these three models all agreed well with the experimental data. Simultaneously, the dissolution enthalpy, dissolution entropy and Gibbs free energy of DCBNT in different solvents were calculated from the solubility data by using the Apelblat model. The results indicate that the dissolution process of DCBNT in these solvents is driven by entropy, which provides theoretical guidance for further research on the crystallization of DCBNT.

2015 ◽  
Vol 775 ◽  
pp. 185-190
Author(s):  
Zi Dan Chen ◽  
Kun Kun Wang ◽  
Xue Li ◽  
Sheng Wang ◽  
Sha Wu ◽  
...  

The solubility of L-proline in binary solvents of methanol and dichloromethane were measured by a dynamic method via a laser monitoring technique. In the binary solvent mixtures, the solubility increases with the increasing of temperature and proportion of the methanol. The experimental solubility were fitted to modified Apelblat equation and Van’t Hoff equation in this work can be used as essential data and models in the purification process of L-proline. The dissolving process is endothermic and the dissolution driving force converts from enthalpy-driving to entropy-driving.


2013 ◽  
Vol 67 (11) ◽  
Author(s):  
Abbas Rostamkolahi ◽  
Abbas Rostami ◽  
Fardad Koohyar ◽  
Farhoush Kiani

AbstractThermodynamic properties (densities and viscosities) of binary mixtures of diethyl phthalate (DEP) + bromocyclohexane, dibutyl phthalate (DBP) + 1,2-dichlorobenzene, and vinyl acetate (1) + dimethyl phthalate (DMP) (2), + diethyl phthalate (2), or + dibutyl phthalate (2) were measured over the whole range of mole fractions at atmospheric pressure and different temperatures (T = 298.15 K to 308.15 K). For these mixtures, their excess molar volumes (V E) and viscosity deviations (Δη) were calculated from the experimental data. These results were correlated with the Redlich-Kister polynomial equation to derive the coefficients and standard errors.


2014 ◽  
Vol 33 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Haitao Liu ◽  
Weiqing Chen ◽  
Wenying Li ◽  
Yanchong Yu

AbstractSolubility of bismuth in liquid Bi-S based free cutting steel was measured using a vapor-liquid equilibration method at 1540–1600 °C, and the recovery rate of bismuth in the steel with different temperatures under an atmospheric pressure was also measured. The results showed that the solubility of bismuth in liquid Bi-S based free cutting steel from experiment under a constant volume at 1540, 1560, 1580, and 1600 °C were 0.174, 0.181, 0.205, and 0.220 mass%, respectively, and the relationship of bismuth solubility vs. temperature could be expressed as lg[%Bi] = −6049/T + 2.572. Meanwhile, the solubility of bismuth increased with the increase of Mn content, but decreased with the increase of C content. The recovery of bismuth in this experiment reached a maximum when the temperature was at bismuth boiling point or so, and then it was decreased with the increase of temperature when the temperature was above 1560 °C, which might be attributed to the accelerating of bismuth evaporation that were caused by the increase of bismuth equilibrium partial pressure above the surface of the molten steel with increasing temperature.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Kapil Bhesaniya ◽  
Shipra Baluja

Some new pyrimidine derivatives have been synthesized and their characterization was done by IR, NMR, and mass spectral data. The solubility of these synthesized compounds has been studied in methanol, N,N dimethylformamide (DMF), and carbon tetrachloride (CCl4) by gravimetrical method from 298.15 to 328.15 K under atmospheric pressure and the solubility data were correlated against temperature. The solubility is found to increase with temperature and order of solubility is DMF > methanol > CCl4. The experimental solubility data is correlated with the modified Apelblat equation. Some thermodynamic parameters such as dissolution enthalpy, Gibbs energy of dissolution, and entropy of mixing have also been calculated.


NANO ◽  
2017 ◽  
Vol 12 (08) ◽  
pp. 1750101 ◽  
Author(s):  
Liming Chen ◽  
Lulu Zhao ◽  
Jie Xu ◽  
Jinlin Long ◽  
Linxi Hou

Metal-free photocatalysts trithiocyanuric acid (C3N3S[Formula: see text] and its polymers were one-step synthesized and used for selective aerobic oxidation of benzyl alcohol under visible light. The S–S bridged C3N3S3 polymers showed higher oxidation activity with increasing polymerization time and reached a maximum at 40[Formula: see text]h. As a major factor, catalysts’ solubility in water at different temperatures (from 298.15[Formula: see text]K to 368.15[Formula: see text]K) was measured at atmospheric pressure. The obtained data were correlated by polynomial empirical equation and modified Apelblat equation, respectively. Experimental results proved that the solubility of C3N3S3 and its polymers increased with increasing temperature. The solubility of C3N3S3 polymers with lower polymerization degree (DP) were better than that of parent C3N3S3 owing to the hydrophilicity caused by a low symmetry and disorder structure, whereas the higher DP could lead to the decrease of polymer solubility and further affect the photocatalytic activity. Thermodynamic properties of the solution system including the enthalpy ([Formula: see text] and heat capacity ([Formula: see text]) were calculated by the modified Apelblat equation.


2008 ◽  
Vol 59 (1) ◽  
pp. 45-48
Author(s):  
Oana Ciocirlan ◽  
Olga Iulian

This paper reports the viscosities measurements for the binary system dimethyl sulfoxide + 1,4-dimethylbenzene over the entire range of mole fraction at 298.15, 303.15, 313.15 and 323.15 K and atmospheric pressure. The experimental viscosities were correlated with the equations of Grunberg-Nissan, Katti-Chaudhri, Hind, Soliman and McAllister; the adjustable binary parameters have been obtained. The excess Gibbs energy of activation of viscous flow (G*E) has been calculated from the experimental measurements and the results were fitted to Redlich-Kister polynomial equation. The obtained negative excess Gibbs free energy of activation and negative Grunberg-Nissan interaction parameter are discussed in structural and interactional terms.


Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 256
Author(s):  
Florentina Golgovici ◽  
Mariana Prodana ◽  
Florentina Gina Ionascu ◽  
Ioana Demetrescu

The purpose of our study is to compare the behavior of two reprocessed dental alloys (NiCr and CoCr) at different temperatures considering the idea that food and drinks in the oral cavity create various compositions at different pH levels; the novelty is the investigation of temperature effect on corrosion parameters and ion release of dental alloys. Electrochemical stability was studied together with morphology, elemental composition and ions release determination. The results obtained are in good concordance: electrochemistry studies reveal that the corrosion rate is increasing by increasing the temperature. From SEM coupled with EDS, the oxide film formed on the surface of the alloys is stable at low temperatures and a trend to break after 310K. ICP-MS results evidence that in accordance with increasing temperature, the quantities of ions released from the alloys immersed in artificial saliva also increase, though they still remain small, less than 20 ppm.


Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1585
Author(s):  
Hanbin Wang ◽  
Jinshun Bi ◽  
Mengxin Liu ◽  
Tingting Han

This work investigates the different sensitivities of an ion-sensitive field-effect transistor (ISFET) based on fully depleted silicon-on-insulator (FDSOI). Using computer-aided design (TCAD) tools, the sensitivity of a single-gate FDSOI based ISFET (FDSOI-ISFET) at different temperatures and the effects of the planar dual-gate structure on the sensitivity are determined. It is found that the sensitivity increases linearly with increasing temperature, reaching 890 mV/pH at 75 °C. By using a dual-gate structure and adjusting the control gate voltage, the sensitivity can be reduced from 750 mV/pH at 0 V control gate voltage to 540 mV/pH at 1 V control gate voltage. The above sensitivity changes are produced because the Nernst limit changes with temperature or the electric field generated by different control gate voltages causes changes in the carrier movement. It is proved that a single FDSOI-ISFET can have adjustable sensitivity by adjusting the operating temperature or the control gate voltage of the dual-gate device.


Author(s):  
Mohammad Jamali ◽  
Amir Abbas Izadpanah ◽  
Masoud Mofarahi

AbstractIn this work, solubility of hydrogen in some alkenes was investigated at different temperatures and pressures. Solubility values were calculated using the Peng–Robinson equation of state. Binary interaction parameters were calculated using fitting the equation of state on experimental data, Group contribution method and Moysan correlations and total average absolute deviation for these methods was 3.90, 17.60 and 13.62, respectively. Because hydrogen solubility in Alkenes is low, Henry’s law for these solutions were investigated, too. Results of calculation showed with increasing temperature, Henry’s constant was decreased. The temperature dependency of Henry’s constants of hydrogen in ethylene and propylene was higher than to other alkenes. In addition, using Van’t Hoff equation, the thermodynamic parameters for dissolution of hydrogen in various alkenes were calculated. Results indicated that the dissolution of hydrogen was spontaneous and endothermic. The total average of dissolution enthalpy ($${\Delta H}^{^\circ }$$ Δ H ∘ ) and Gibbs free energy ($${\Delta G}^{^\circ }$$ Δ G ∘ ) for these systems was 3.867 kJ/mol and 6.361 kJ/mol, respectively. But dissolution of hydrogen in almost of alkenes was not an entropy-driven process.


2009 ◽  
Vol 615-617 ◽  
pp. 311-314 ◽  
Author(s):  
W.S. Loh ◽  
J.P.R. David ◽  
B.K. Ng ◽  
Stanislav I. Soloviev ◽  
Peter M. Sandvik ◽  
...  

Hole initiated multiplication characteristics of 4H-SiC Separate Absorption and Multiplication Avalanche Photodiodes (SAM-APDs) with a n- multiplication layer of 2.7 µm were obtained using 325nm excitation at temperatures ranging from 300 to 450K. The breakdown voltages increased by 200mV/K over the investigated temperature range, which indicates a positive temperature coefficient. Local ionization coefficients, including the extracted temperature dependencies, were derived in the form of the Chynoweth expression and were used to predict the hole multiplication characteristics at different temperatures. Good agreement was obtained between the measured and the modeled multiplication using these ionization coefficients. The impact ionization coefficients decreased with increasing temperature, corresponding to an increase in breakdown voltage. This result agrees well with the multiplication characteristics and can be attributed to phonon scattering enhanced carrier cooling which has suppressed the ionization process at high temperatures. Hence, a much higher electric field is required to achieve the same ionization rates.


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