A Theoretical Model for Computing Freezing Point Depression of Lithium-Ion Battery Electrolytes

Reliable prediction of freezing point depression in liquid electrolytes will accelerate the development of improved Li-ion batteries which can operate in low temperature environments. In this work we establish a computational methodology to calculate activity coefficients and liquidus lines for battery-relevant liquid electrolytes. Electronic structure methods are used in conjunction with classical molecular dynamics simulations and theoretical expressions for Born solvation energy, ion-atmosphere effects from Debye-Hückel theory and solvent entropic effects. The framework uses no a priori knowledge beyond neat solvent properties and the concentration of salt. LiPF 6 in propylene carbonate (PC), LiPF 6 in dimethyl carbonate (DMC) and LiClO4 in DMC are investigated up to 1 molal with accuracy better than 3◦C when compared to experimental freezing point measurements. We find that the difference in freezing point depression between the propylene carbonate-based electrolyte and the dimethyl cabonate electrolytes originates from the difference in the solvent dielectric constant.

Lactose quantification in UHT milk by high-performance liquid chromatography and cryoscopy (freezing point depression)

Due to the large number of people with lactose maldigestion, the dairy industries have increased production and diversity of low lactose and lactose-free foods. Consequently, the need to control the lactose hydrolysis process has also risen. This study aimed to correlate freezing point depression (cryoscopy) and lactose concentration, quantified by high-performance liquid chromatography (HPLC), in UHT milk. To accomplish this, UHT milk samples were subjected to seven lactose hydrolysis treatments, using lactase enzyme, resulting in different lactose concentrations. All samples were subjected to HPLC analysis and freezing point measurement, using a cryoscope. The results were plotted on a graph and a linear regression was performed. There was a strong correlation between lactose concentration and freezing point (R = 0,9973) and the coefficient of determination (R2) was 0,9946, which means that 99,46% of the variability of the response data is explained by the linear regression model. Therefore, the results point to the feasibility of estimating the lactose concentration in milk during the hydrolysis process for the production of low lactose milk, by cryoscopy, a quick analysis, with lower cost compared to HPLC and that is already among the analyses commonly performed in dairy industries.

Ideal Solutions and Colligative Properties

Ideal Solutions and Colligative Properties deals with the properties of solutions that depend on the concentration, but not the identity, of solute particles. The discussion examines the solution properties of vapour pressure depression, boiling point elevation, freezing point depression and osmotic pressure for an ideal solution, and how they differ from the properties of the pure solvent. Raoult’s law is used to quantify the magnitude of vapour pressure lowering. This is followed by illustrations of boiling point elevation and freezing point depression as well as the determination of boiling and freezing points of a solution. Calculation of osmotic pressure and its use to determine the molar mass of a solute is discussed.

Thermal Convection in the Core of Ganymede Inferred from Liquid Eutectic Fe-FeS Electrical Resistivity at High Pressures

The core of Ganymede is suggested to be mainly Fe but with a significant proportion of S. Effects of S as a core constituent are freezing-point depression, allowing for a molten core at relatively low core temperatures, and modification of transport properties that can influence the dynamo and thermal evolution. The electrical resistivity of solid and liquid Fe-FeS (~24–30 wt.% S) was measured up to 5 GPa and thermal conductivity was calculated using the Wiedemann–Franz law. These first well-constrained experimental data on near eutectic Fe-FeS compositions showed intermediate values of electrical and thermal conductivities compared to the end-members. Eutectic temperatures were delineated from the solid to liquid transition, inferred from sharp changes in electrical resistivity, at each pressure. Combined with thermal models, our calculated estimates of the adiabatic heat flow of a molten Fe-FeS eutectic composition core model of Ganymede showed that thermal convection is permissible.

Daily water regime and sample sampling affect blood and urine parameter value change in healthy individuals

Background Homeostasis is a mechanism for maintaining a stable inner environment in healthy participants. Blood and urine biomarkers are indicators of the subject health status. Biomarkers apply for early diagnosis, prognosis, and treatment. Understanding the effect of pre-analytical factors on biomarker range is significant for the data quality of bio-specimens, reproducibility, and minimizing potential results errors. Water as a necessary element for the normal functioning of living beings and sampling frequency as pre-analytical factors influences the homeostatic range of parameters. The purpose of the study is to examine the effect of 9-day fluid intake and 2-time sampling on concentration changes of 7-urine (freezing point depression, potassium, sodium, chloride, urea, creatinine, urate) and 17-blood (urea, creatinine, urate, glucose, C-reactive protein, leukocytes, erythrocytes, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, mean platelet volume, thrombocytes, potassium, sodium, and chloride) variables. Methods Parametric and non-parametric test apply to data processing with SPSS software v23.0. Results The group of 23 healthy subjects was divide based on water intake (test: more than 1800 ml; control: less than 2000 ml) and gender (female: 10(43%); male: 13(57%)). The mean value of the amount of fluid consumed for the test group is 2183.33 ml, while the control is 1395.83 ml. Investigated parameters, freezing point depression, sodium, potassium, creatinine urea and urate in urine, urea, urate, glucose, hematocrit, and thrombocyte in blood show a significant difference (P < 0.01) between the first and second sampling. The difference between water intake after first sampling (P < 0.01) observes for freezing point depression, sodium, urate, and (P < 0.05) for potassium (P < 0.05), chloride (P < 0.05), creatinine (P < 0.05), urate, urea in urine and potassium (P < 0.01), and chloride (P < 0.05) in blood. Difference between gender exists for urea (P < 0.05) in urine after second sampling and urate (P < 0.01), glucose (P < 0.01/0.05), hematocrit (P < 0.01/0.05) after the first and second sampling, and mean corpuscular hemoglobin concentration (P < 0.01) after secondary sampling in blood samples. Conclusion Water intake increases the blood and urine biomarker range after the first and second sampling. Further studies should include a larger number of participants to get precise reference limits in a healthy population. Compare health and disease states to draw practical clinical conclusions.

Evaluation of Milk Yield and Milk Composition of Honamlı Goats

The aim of this study was to determine the milk yield and milk composition (total solids, fat, protein and lactose), freezing point depressionand somatic cell counts of Honamlı goat during second lactationin Turkey. The animal material of the study consisted of a total of 30 goat. Total milk yield was detected by using Fleischmann’s method. Milk composition was analyzed by Bentley 150, and somatic cells were counted by Bentley Somacount FC. One-way ANOVA was used to determine the effect of lactation stages on milk yield and milk composition. In the study, mean lactation period and lactation milk yield of Honamlı goat were detected as 202.4 days, and 92.6 kg, respectively. The percentages of fat, protein, lactose, total solid, freezing point depression, and somatic cell counts /mL of milk were 2.4%, 4.2%, 5.1%, 12.7%, -0.57 °C, 82.8 and 2.9%, 4.2%, 4.7%, 12.7%, -0.59 °C, 483 on the 60th and 120thlactation day respectively. Total solids, fat, and protein values significantly increased especially towards the end of lactation (P <0.05). Lactose value decreased slowly from the beginning to the end of lactation. The somatic cell counts increased in milk particularly at the end of lactation (P < 0.05). The freezing point depression remained stable throughout lactation. It was thought that results of study were important representing the second lactation milk production of Honamlı goats that is one of the native goat breeds of Turkey.