scholarly journals Spatiotemporal Analysis of Hydration Mechanism in Sodium Alginate Matrix Tablets

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 646
Author(s):  
Ewelina Juszczyk ◽  
Piotr Kulinowski ◽  
Ewelina Baran ◽  
Artur Birczyński ◽  
Dorota Majda ◽  
...  
Keyword(s):  
Water Content ◽  
Spatial Resolution ◽  
Water Distribution ◽  
Spatiotemporal Analysis ◽  
High Water ◽  
Matrix Tablets ◽  
High Water Content ◽  
Hydrated Layer ◽  
Order Of Magnitude

Methods of spatiotemporal characterization of nonequilibrated polymer based matrices are still immature and imperfect. The purpose of the study was to develop the methodology for the spatiotemporal characterization of water transport and properties in alginate tablets under hydration. The regions of low water content were spatially and temporally sampled using Karl Fisher and Differential Scanning Callorimetry (spatial distribution of freezing/nonfreezing water) with spatial resolution of 1 mm. In the regions of high water content, where sampling was infeasible due to gel/sol consistency, magnetic resonance imaging (MRI) enabled characterization with an order of magnitude higher spatial resolution. The minimally hydrated layer (MHL), infiltration layer (IL) and fully hydrated layer (FHL) were identified in the unilaterally hydrated matrices. The MHL gained water from the first hour of incubation (5–10% w/w) and at 4 h total water content was 29–39% with nonfreezing pool of 28–29%. The water content in the IL was 45–47% and at 4 h it reached ~50% with the nonfreezing pool of 28% and T2 relaxation time < 10 ms. The FHL consisted of gel and sol layer with water content of 85–86% with a nonfreezing pool of 11% at 4 h and T2 in the range 20–200 ms. Hybrid destructive/nondestructive analysis of alginate matrices under hydration was proposed. It allowed assessing the temporal changes of water distribution, its mobility and interaction with matrices in identified layers.

scholarly journals Numerical Sensitivity Analysis for Dielectric Characterization of Biological Samples by Open-Ended Probe Technique

Sensors ◽  
2020 ◽  
Vol 20 (13) ◽  
pp. 3756
Author(s):  
Marta Cavagnaro ◽  
Giuseppe Ruvio
Keyword(s):  
Water Content ◽  
Ex Vivo ◽  
High Water ◽  
Biological Tissues ◽  
Fundamental Aspect ◽  
High Water Content ◽  
Insertion Depth ◽  
Dielectric Characterization

Dielectric characterization of biological tissues has become a fundamental aspect of the design of medical treatments based on electromagnetic energy delivery and their pre-treatment planning. Among several measuring techniques proposed in the literature, broadband and minimally-invasive open-ended probe measurements are best-suited for biological tissues. However, several challenges related to measurement accuracy arise when dealing with biological tissues in both ex vivo and in vivo scenarios such as very constrained set-ups in terms of limited sample size and probe positioning. By means of the Finite Integration Technique in the CST Studio Suite® software, the numerical accuracy of the reconstruction of the complex permittivity of a high water-content tissue such as liver and a low water-content tissue such as fat is evaluated for different sample dimensions, different location of the probe, and considering the influence of the background environment. It is found that for high water-content tissues, the insertion depth of the probe into the sample is the most critical parameter on the accuracy of the reconstruction. Whereas when low water-content tissues are measured, the probe could be simply placed in contact with the surface of the sample but a deeper and wider sample is required to mitigate biasing effects from the background environment. The numerical analysis proves to be a valid tool to assess the suitability of a measurement set-up for a target accuracy threshold.

High Water Content Areas Identified In Equatorial Band of Mars by FREND Neutron Telescope Onboard ExoMars TGO

2021 ◽  
Author(s):  
Alexey Malakhov ◽  
Igor Mitrofanov ◽  
Maxim Litvak ◽  
Anton Sanin ◽  
Dmitry Golovin ◽  
...  
Keyword(s):  
Water Content ◽  
Spatial Resolution ◽  
Search Algorithm ◽  
Statistical Significance ◽  
High Water ◽  
Weight Percent ◽  
High Water Content ◽  
Polar Regions ◽  
Valles Marineris ◽  
Equatorial Band

&lt;p&gt;FREND is a neutron telescope installed onboard Russian-European ExoMars mission Trace Gas Orbiter. Neutron measurements from orbit are a good characteristic of water content in the subsurface of Mars down to 1 meter in depth. The instrument&amp;#8217;s major characteristic is its neutron collimator that narrows significantly the field of view allowing for mapping with high spatial resolution of 60-200 km.&lt;/p&gt;&lt;p&gt;Previous missions (e.g. HEND experiment on NASA&amp;#8217;s Mars Odyssey) showed that water content is enhanced mainly in Martian polar regions and at Arabia area, however spatial resolution of these instruments only allowed to map the surface with a resolution of several hundreds of kilometers. A study performed on FREND data accumulated during its science mission between May 2018 and January 2021 was targeted on equatorial band of &amp;#177;40&amp;#176; latitude. We identified several local areas with enhanced mass fraction of water and performed a thorough analysis of each of them to identify the water content and estimate statistical significance of such wet spots.&lt;/p&gt;&lt;p&gt;The locations found are associated with major Martian relief formations, e.g. Olympus Mons, Ascraeus Mons, Xanthe Terra, Valles Marineris and others, each showing water content of tens of weight percent (wt%), with good statistical certainty above 3&amp;#963; relative to the immediate dry surroundings.&lt;/p&gt;&lt;p&gt;In this talk we will present the areas identified as well as explain the search algorithm and water content estimation techniques.&lt;/p&gt;

scholarly journals Characterization of the Undrained Shear Strength of Expansive Soils of High Water Content

2018 ◽  
Vol 206 ◽  
pp. 01002
Author(s):  
Zheng Su ◽  
Daokun Qi ◽  
Xinju Guo ◽  
Xiaojuan Xi ◽  
Liang Zhang
Keyword(s):  
Shear Strength ◽  
Water Content ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Friction Angle ◽  
High Water ◽  
Ease Of Use ◽  
Triaxial Tests ◽  
High Water Content

In recent years, engineering constructions increase rapidly in western and central areas of China, where expansive soil widely distributes. Since expansive soil is sensitive to water content, the characterization of its shear strength should be carefully conducted. For simplicity and ease of use, the Mohr-Coulomb criterion is often adopted to describe the shear strength of expansive soil. In this paper, the physical meaning of the cohesion and frictional strength of expansive soil are explained, and the variations of the strength parameters with water content are investigated. By fitting to the experimental results from direct shear test and triaxial tests, the changing characteristics of cohesion and friction angle with water content are obtained.

scholarly journals Preparation and characterization of a supramolecular hydrogel made of phospholipids and oleic acid with a high water content

2020 ◽  
Vol 8 (1) ◽  
pp. 161-167 ◽  
Author(s):  
Kirian Talló ◽  
Manel Bosch ◽  
Ramon Pons ◽  
Mercedes Cocera ◽  
Olga López
Keyword(s):  
Oleic Acid ◽  
Water Content ◽  
High Water ◽  
Structured Lipid ◽  
High Water Content ◽  
Supramolecular Hydrogel ◽  
Gelling Agents

Formation of a structured lipid hydrogel able to accommodate a high amount of water (95%) without needing gelling agents.

Synthesis and Characterization of Monosaccharide-Containing 2-(α-D-mannopyranosyloxy)Ethyl Methacrylate as a Surface Modifier for Hydrogels

2020 ◽  
Vol 20 (9) ◽  
pp. 5609-5613
Author(s):  
Shengnan Wu ◽  
Chanhong Chung ◽  
Younghwan Kwon
Keyword(s):  
Water Content ◽  
Contact Lenses ◽  
High Water ◽  
High Water Content ◽  
Hydroxyl Groups ◽  
Silicone Hydrogel ◽  
Surface Modifier ◽  
Ethyl Methacrylate ◽  
Silicone Polymers

We introduce a hydrophilic monosaccharide-containing 2-(α-D-mannopyranosyloxy)ethyl methacrylate (ManEMA) in this study to achieve more extended and comfortable wear silicone hydrogel contact lenses by increasing water content. Molecular structure of ManEMA contains a monosaccharide moiety with four hydroxyl groups, which provide a strong interaction with water. Therefore, the ManEMA-containing hydrogels are expected to have high water content. The structure of synthesized ManEMA is confirmed by 1H and 13C NMR spectroscopy. Contact lenses containing silicone polymers are coated with a monosaccharide-containingManEMA monomer with the help of plasma treatment and the use of 3-(trimethoxylsilyl)propyl methacrylate to provide an increased hydrophilicity. The feasibility of ManEMA as a surface modifier of silicone lenses is investigated in terms of water content and surface energy.

Hydrogels as Antibacterial Biomaterials

2018 ◽  
Vol 24 (8) ◽  
pp. 843-854 ◽  
Author(s):  
Weiguo Xu ◽  
Shujun Dong ◽  
Yuping Han ◽  
Shuqiang Li ◽  
Yang Liu
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Tissue Engineering ◽  
Water Content ◽  
Oxygen Permeability ◽  
Structural Diversity ◽  
High Water ◽  
Clinical Applications ◽  
High Water Content ◽  
Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

Microwave-Induced Thermoacoustic Imaging for Embedded Explosives Detection in High-Water Content Medium

2019 ◽  
Vol 67 (7) ◽  
pp. 4803-4810 ◽  
Author(s):  
Xiong Wang ◽  
Tao Qin ◽  
Yexian Qin ◽  
Ahmed H. Abdelrahman ◽  
Russell S. Witte ◽  
...  
Keyword(s):  
Water Content ◽  
High Water ◽  
Explosives Detection ◽  
High Water Content ◽  
Thermoacoustic Imaging

scholarly journals Deep mantle melting, global water circulation and its implications for the stability of the ocean mass

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Shun-ichiro Karato ◽  
Bijaya Karki ◽  
Jeffrey Park
Keyword(s):  
Phase Transformation ◽  
Water Content ◽  
Sea Level ◽  
High Water ◽  
Water Circulation ◽  
Mantle Melting ◽  
High Water Content ◽  
Mineral Physics ◽  
Deep Mantle ◽  
Global Water

AbstractOceans on Earth are present as a result of dynamic equilibrium between degassing and regassing through the interaction with Earth’s interior. We review mineral physics, geophysical, and geochemical studies related to the global water circulation and conclude that the water content has a peak in the mantle transition zone (MTZ) with a value of 0.1–1 wt% (with large regional variations). When water-rich MTZ materials are transported out of the MTZ, partial melting occurs. Vertical direction of melt migration is determined by the density contrast between the melts and coexisting minerals. Because a density change associated with a phase transformation occurs sharply for a solid but more gradually for a melt, melts formed above the phase transformation depth are generally heavier than solids, whereas melts formed below the transformation depth are lighter than solids. Consequently, hydrous melts formed either above or below the MTZ return to the MTZ, maintaining its high water content. However, the MTZ water content cannot increase without limit. The melt-solid density contrast above the 410 km depends on the temperature. In cooler regions, melting will occur only in the presence of very water-rich materials. Melts produced in these regions have high water content and hence can be buoyant above the 410 km, removing water from the MTZ. Consequently, cooler regions of melting act as a water valve to maintain the water content of the MTZ near its threshold level (~ 0.1–1.0 wt%). Mass-balance considerations explain the observed near-constant sea-level despite large fluctuations over Earth history. Observations suggesting deep-mantle melting are reviewed including the presence of low-velocity anomalies just above and below the MTZ and geochemical evidence for hydrous melts formed in the MTZ. However, the interpretation of long-term sea-level change and the role of deep mantle melting in the global water circulation are non-unique and alternative models are reviewed. Possible future directions of studies on the global water circulation are proposed including geodynamic modeling, mineral physics and observational studies, and studies integrating results from different disciplines.

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