The Dimerization Constant of Nitrobenzene in Benzene: A Critique of Partition as a Thermodynamic Method

1974 ◽  
Vol 52 (23) ◽  
pp. 3918-3931 ◽  
Author(s):  
Saul Goldman ◽  
Wayne C. Duer
Keyword(s):  
Solvent Extraction ◽  
Anhydrous Benzene ◽  
Freezing Point ◽  
Thermodynamic Method ◽  
Electrostatic Model ◽  
Freezing Point Depression ◽  
Heat Of Solution ◽  
Dimerization Constant ◽  
A Value ◽  
The Difference

The dimerization constant (K) of nitrobenzene in benzene was determined at 5.5 and 25 °C by means of partition (solvent extraction). A hydration study was performed at these temperatures to determine the extent of hydration of nitrobenzene in the benzene phase. Published freezing point depression data for the anhydrous benzene–nitrobenzene system were used to obtain a value of K at 5.5 °C. The heats of solution of nitrobenzene in benzene (anhydrous) were determined at 25 °C. The heat of solution and freezing point depression data were combined to obtain a value of K for the anhydrous system at 25 °C. At each of 5.5 and 25 °C the value of K determined by partition was significantly smaller than the corresponding value of K for the anhydrous system, and the discrepancy was larger at 25 than at 5.5 °C. It was found that by fitting a simple electrostatic model to the difference in the values of K found at 5.5 °C, the difference at 25 °C could be predicted.

scholarly journals Association of Blood and Urine Parameter Value Change With the Amount of Consumed Water Regime and Sample Sampling in Healthy Individuals

2021 ◽  
Author(s):  
Snezana M Jovicic
Keyword(s):  
Water Intake ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
Sodium Potassium ◽  
Significant Difference ◽  
Urine Biomarker ◽  
Concentration Changes ◽  
The Difference ◽  
And Gender

Abstract Background: Understanding the effect of pre-analytical factors is important for data quality of bio-specimens and health status. The study examines the effect of 9-days fluid intake and 2-time sampling on concentration changes of 7-Urine and 17-Blood variables. Material and Method: SPSS software v23.0 applies to data processing. The group of 23 healthy subjects divide based on water intake and gender. Results: A statistically significant difference(p<0.01) between 1st/2nd sampling is confirmed for Freezing point depression, Sodium, Potassium, Creatinine Urea and Urate in Urine and Urea, Urate, Glucose, Hematocrit, Thrombocyte in Blood. The difference between water intake after 1st sampling is confirmed (p<0.01) 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 2nd sampling and Urate(P<0.01), Glucose(p<0.01/0.05), Ht(p<0.01/0.05) after 1st and 2nd sampling and MCHC(p<0.01) after 2nd sampling in Blood samples.Conclusion: Water intake increases blood and urine biomarker range after sampling.

Osmoregulation in Ligia Oceanica and Idotea Granulosa

1963 ◽  
Vol 40 (2) ◽  
pp. 381-392
Author(s):  
MARY E. TODD
Keyword(s):  
Blood Concentration ◽  
Sea Water ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
External Concentration ◽  
Osmotic Concentration ◽  
Test Range ◽  
The Mean ◽  
The Difference ◽  
Idotea Granulosa

1. The osmoregulatory response of Ligia oceanica and Idotea granulosa to the range of the experimental variables was similar. They were both hyperosmotic relative to the medium and the difference between internal and external concentration increased as the salinity of the medium decreased. 2. In 100% sea water the osmotic concentration of the blood of Ligia oceanica was markedly above that of the medium, whereas in Idotea granulosa the blood was only marginally hyperosmotic. 3. In Ligia oceanica the blood concentration changed little in 100 and 75% sea water, but dropped significantly between 75 and 50% sea water, whereas blood concentration in Idotea granulosa dropped significantly throughout the test range of salinities. 4. The more efficient osmoregulation of Ligia oceanica in 25% sea water is reflected in the mean freezing-point depression of the blood, Δi = 1.65, compared with Δi = 0.90 in Idotea granulosa. 5. In both species the osmotic concentration of the blood was influenced by season, by temperature and by a temperature-salinity interaction. 6. Neither size nor sex of the animal influenced osmotic concentration of the blood.

scholarly journals Daily water regime and sample sampling affect Blood and Urine parameter value change in healthy individuals

2021 ◽  
Author(s):  
Snezana M Jovicic
Keyword(s):  
Water Intake ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
Urine Biomarkers ◽  
Significant Difference ◽  
Daily Water ◽  
Urine Biomarker ◽  
Concentration Changes ◽  
The Difference ◽  
And Gender

Abstract Background: Blood and Urine biomarkers are indicators of the subject health status. Understanding the effect of pre-analytical factors is important for the data quality of bio-specimens. Water as a necessary element for the normal functioning of living beings and sampling frequency influences the homeostatic range of parameters. The study examines the effect of 9-days fluid intake and 2-time sampling on concentration changes of 7-Urine and 17-Blood variables. Material and Method: SPSS software v23.0 applies to data processing. The group of 23 healthy subjects divide based on water intake and gender. Results: A statistically significant difference(p<0.01) between 1st/2nd sampling is confirmed for Freezing point depression, Sodium, Potassium, Creatinine Urea and Urate in Urine, Urea, Urate, Glucose, Hematocrit, Thrombocyte in Blood. The difference between water intake after 1st sampling is confirmed (p<0.01) 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 2nd sampling and Urate(P<0.01), Glucose(p<0.01/0.05), Ht(p<0.01/0.05) after 1st and 2nd sampling and MCHC(p<0.01) after 2nd sampling in Blood samples. Conclusion: Water intake increases Blood and Urine biomarker range after sampling.

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

2021 ◽  
Author(s):  
Julian Self ◽  
Helen K Bergstrom ◽  
Kara D Fong ◽  
Bryan D Mccloskey ◽  
Kristin A. Persson
Keyword(s):  
Propylene Carbonate ◽  
Freezing Point ◽  
A Priori ◽  
Lithium Ion ◽  
Freezing Point Depression ◽  
Liquid Electrolytes ◽  
Hückel Theory ◽  
The Difference ◽  
Dynamics Simulations ◽  
Entropic Effects

Abstract 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.

scholarly journals Osmolality of Commonly Used Oral Medications in the Neonatal Intensive Care Unit

2021 ◽  
Vol 26 (2) ◽  
pp. 172-178
Author(s):  
Dhara D. Shah ◽  
Andriy Kuzmov ◽  
Dana Clausen ◽  
Anita Siu ◽  
Christine A. Robinson ◽  
...  
Keyword(s):  
Enteral Nutrition ◽  
Neonatal Intensive Care ◽  
Low Birthweight ◽  
Freezing Point ◽  
Freezing Point Depression ◽  
Term Infants ◽  
Gastrointestinal Complications ◽  
Oral Medications ◽  
A Value ◽  
American Academy Of Pediatrics

OBJECTIVE The administration of hyperosmolar oral products in neonates has been associated with gastrointestinal complications. The American Academy of Pediatrics recommends a maximum osmolality of 450 mOsm/kg for formulas and enteral nutrition for term infants, and recent studies reported intolerance to enteral nutrition with osmolality above 500 mOsm/kg in low birthweight infants. The osmolality of medications administered to neonates is often not available in the literature or from manufacturers. The purpose of this study was to determine the osmolality of oral medications commonly administered to neonates in the NICU. METHODS Fifty-two oral medications were chosen for this study, including solutions, suspensions, syrups, elixirs, and intravenous solutions administered orally. The osmolality of each medication was measured in triplicate by using freezing point depression. RESULTS Thirty-seven of the 43 medications with measurable values (86.1%) had an osmolality greater than 500 mOsm/kg, and 6 medications (14%) had an osmolality less than 500 mOsm/kg. Nine medications did not result in a value. CONCLUSIONS Our study provides osmolality data on oral medications commonly used in neonates with most oral medications having an osmolality greater than 500 mOsm/kg.

Depression of freezing temperature of water and water solutions in porous materials

1989 ◽  
Vol 54 (10) ◽  
pp. 2644-2647 ◽  
Author(s):  
Petr Schneider ◽  
Jiří Rathouský
Keyword(s):  
Water Vapor ◽  
Porous Materials ◽  
Inorganic Salt ◽  
Freezing Point ◽  
Freezing Temperature ◽  
Inorganic Salts ◽  
Freezing Point Depression ◽  
Salt Solutions ◽  
Water Solutions

In porous materials filled with water or water solutions of inorganic salts, water freezes at lower temperatures than under normal conditions; the reason is the decrease of water vapor tension above the convex meniscus of liquid in pores. The freezing point depression is not very significant in pores with radii from 0.05 μm to 10 μm (about 0.01-2.5 K). Only in smaller pores, especially when filled with inorganic salt solutions, this depression is important.

scholarly journals The Water Footprint of Primary and Secondary Processing of Beef from Different Cattle Breeds: A Value Fraction Allocation Model

2021 ◽  
Vol 13 (12) ◽  
pp. 6914
Author(s):  
Frikkie Alberts Maré ◽  
Henry Jordaan
Keyword(s):  
Water Footprint ◽  
Negative Relationship ◽  
High Water ◽  
Allocation Model ◽  
Cattle Breeds ◽  
A Value ◽  
Average Production ◽  
High Water Intake ◽  
The Difference ◽  
By Products

The high water intake and wastewater discharge of slaughterhouses have been a concern for many years. One neglected factor in previous research is allocating the water footprint (WF) to beef production’s different products and by-products. The objective of this article was to estimate the WF of different cattle breeds at a slaughterhouse and cutting plant and allocate it according to the different cuts (products) and by-products of beef based on the value fraction of each. The results indicated a negative relationship between the carcass weight and the processing WF when the different breeds were compared. Regarding a specific cut of beef, a kilogram of rib eye from the heaviest breed had a processing WF of 614.57 L/kg, compared to the 919.91 L/kg for the rib eye of the lightest breed. A comparison of the different cuts indicated that high-value cuts had higher WFs than low-value cuts. The difference between a kilogram of rib eye and flank was 426.26 L/kg for the heaviest breed and 637.86 L/kg for the lightest breed. An option to reduce the processing WF of beef is to lessen the WF by slaughtering heavier animals. This will require no extra investment from the slaughterhouse. At the same time, the returns should increase as the average production inputs per kilogram of output (carcass) should reduce, as the slaughterhouse will process more kilograms.

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