Near-Infrared and Heat Capacity Investigations of the State of Water in Surfactant and Alcohol Solutions

1982 ◽  
pp. 431-453 ◽  
Author(s):  
Y. DeGrandpré ◽  
J. B. Rosenholm ◽  
L. L. Lemelin ◽  
C. Jolicoeur
Keyword(s):  
Heat Capacity ◽  
Near Infrared ◽  
The State ◽  
State Of Water

scholarly journals Water Properties of Soft Contact Lenses: A Comparative Near-Infrared Study of Two Hydrogel Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Jelena Munćan ◽  
Ivana Mileusnić ◽  
Jovana Šakota Rosić ◽  
Aleksandra Vasić-Milovanović ◽  
Lidija Matija
Keyword(s):  
Water Content ◽  
Near Infrared ◽  
Contact Lenses ◽  
Polymer Network ◽  
The State ◽  
Vinyl Pyrrolidone ◽  
Soft Contact ◽  
Infrared Study ◽  
Soft Contact Lenses ◽  
State Of Water

The functionality of soft contact lenses depends strongly on the water content and their water-transport ability. This study was conducted in order to examine the state of water in two sets of soft contact lenses: VSO38, pHEMA Filcon I 1, and VSO50, copolymer of HEMA and VP Filcon II 1 (HEMA = 2-hydroxy-ethyl methacrylate; VP = vinyl pyrrolidone). Hydrogel lenses were studied using near-infrared spectroscopy and the novel Aquaphotomics approach in order to determine the state of water in materials based on their near-infrared spectra. Aquaphotomics approach investigates absorption at specific vibrational bands of water’s covalent and hydrogen bonds which can provide information on how the water structure changes with the structural change of the polymer network. Principal component analysis and specific star-chart “aquagram” were used to analyse water spectral pattern in hydrogel materials. The findings show that material VSO38 has water predominantly organized in bound state, while material with higher water content, VSO50, has more free and weakly hydrogen bonded water. Our findings define in detail exact water species existing and interacting with the polymer network. The results show qualitative and quantitative possibilities of Aquaphotomics for better modelling and understanding water behaviour in hydrogel materials.

Heat capacity of birch determined by calorimetry: implications for the state of water in plants

2000 ◽  
Vol 349 (1-2) ◽  
pp. 79-88 ◽  
Author(s):  
Henrik Hedlund ◽  
Peter Johansson
Keyword(s):  
Heat Capacity ◽  
The State ◽  
State Of Water

The state of water in soft contact lenses explored with near infrared spectroscopy and Aquaphotomics

NIR news ◽  
2017 ◽  
Vol 28 (6) ◽  
pp. 9-12
Author(s):  
Jelena Munćan
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Contact Lenses ◽  
Water Structure ◽  
The State ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
State Of Water ◽  
Three State Model

The structure of water in hydrogel materials of soft contact lenses was investigated by near infrared spectroscopy and Aquaphotomics. Near infrared spectroscopy offers rapid, reagent free, and nondestructive characterization of hydrogel materials, while Aquaphotomics provides detailed insight into the complex water structure inside the hydrogel consisting of many water molecular species. These findings push the limits of our knowledge beyond the current “three-state” model of water in hydrogels, while at the same time provide information about the state of the polymer itself thus justifying the “water molecular-mirror” concept of Aquaphotomics.

ELECTRODYNAMIC SENSOR FOR ASSESSING TRANSFORMATIONS OF THE STATE OF WATER IN BIOLOGICAL OBJECTS

2018 ◽  
Vol 77 (12) ◽  
pp. 1103-1112
Author(s):  
Ch. Liu ◽  
I. N. Bondarenko ◽  
A. Yu. Panchenko ◽  
N. I. Slipchenko
Keyword(s):  
The State ◽  
Biological Objects ◽  
State Of Water

ELECTRODYNAMIC SENSOR FOR DETERMINING THE STATE OF WATER IN BIOLOGICAL OBJECTS

2019 ◽  
Vol 78 (9) ◽  
pp. 801-811
Author(s):  
Ch. Liu ◽  
I. N. Bondarenko ◽  
A. Yu. Panchenko ◽  
N. I. Slipchenko
Keyword(s):  
The State ◽  
Biological Objects ◽  
State Of Water

CONSIDERATION OF THE VALIDITY OF THE STATISTICAL CHARACTERISTICS OF pH IN SURFACE WATERS

2019 ◽  
Vol 13 (2) ◽  
pp. 52-58
Author(s):  
V. B. Korobov ◽  
I. V. Miskevich ◽  
A. S. Lokhov ◽  
K. A. Seredkin
Keyword(s):  
Field Measurements ◽  
Heavy Precipitation ◽  
The State ◽  
Statistical Characteristics ◽  
Mean Values ◽  
River Waters ◽  
Ph Values ◽  
State Of Water ◽  
Environment Temperature ◽  
Unit Characteristic

Abstract: pH is one of the most important parameters characterizing the state of water systems. The arithmetic mean values of samples are often used when averaging serial pH measurements in water bodies, as is usually done for other characteristics of the state of the natural environment (temperature, salinity, oxygen concentrations, suspended solids, etc.). However, in this case such an operation is illegal, since the addition of logarithms, which by definition are pH, is non-additive. The authors conducted a study to determine the extent to which pH variability in natural objects such an operation would not distort the results. For this, several samples of the pH index were generated in various ranges of its theoretically possible and natural variability. It was established that with pH variability of less than a unit characteristic of marine pH values, the statistical characteristics of the indicator and [H+ ] concentrations differ slightly, and the medians of the samples coincide. It is concluded that with such ranges characteristic of the waters of the oceans, there is no need to recalculate previously obtained results. However, for the estuaries of rivers flowing into tidal seas, as shown by field measurements, the pH variability in the mixing zone of sea and river waters is several times higher. Similar situations may occur when heavy precipitation falls on the water surface, as well as during floods. In these cases, a simple averaging of the pH values will no longer be correct. In such cases, the use of other averaging algorithms and the choice of stable statistical characteristics are required.

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