Phase Transitions of Pea Starch over a Wide Range of Water Content

2012 ◽  
Vol 60 (25) ◽  
pp. 6439-6446 ◽  
Author(s):  
Shujun Wang ◽  
Les Copeland



Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1786
Author(s):  
Carla Queirós ◽  
Chen Sun ◽  
Ana M. G. Silva ◽  
Baltazar de Castro ◽  
Juan Cabanillas-Gonzalez ◽  
...  

The development of straightforward reproducible methods for the preparation of new photoluminescent coordination polymers (CPs) is an important goal in luminescence and chemical sensing fields. Isophthalic acid derivatives have been reported for a wide range of applications, and in addition to their relatively low cost, have encouraged its use in the preparation of novel lanthanide-based coordination polymers (LnCPs). Considering that the photoluminescent properties of these CPs are highly dependent on the existence of water molecules in the crystal structure, our research efforts are now focused on the preparation of CP with the lowest water content possible, while considering a green chemistry approach. One- and two-dimensional (1D and 2D) LnCPs were prepared from 5-aminoisophthalic acid and Sm3+/Tb3+ using hydrothermal and/or microwave-assisted synthesis. The unprecedented LnCPs were characterized by single-crystal X-ray diffraction (SCRXD), powder X-ray diffraction (PXRD), Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM), and their photoluminescence (PL) properties were studied in the solid state, at room temperature, using the CPs as powders and encapsulated in poly(methyl methacrylate (PMMA) films, envisaging the potential preparation of devices for sensing. The materials revealed interesting PL properties that depend on the dimensionality, metal ion, co-ligand used and water content.



2012 ◽  
Vol 29 (7) ◽  
pp. 933-943 ◽  
Author(s):  
Weinan Pan ◽  
R. P. Boyles ◽  
J. G. White ◽  
J. L. Heitman

Abstract Soil moisture has important implications for meteorology, climatology, hydrology, and agriculture. This has led to growing interest in development of in situ soil moisture monitoring networks. Measurement interpretation is severely limited without soil property data. In North Carolina, soil moisture has been monitored since 1999 as a routine parameter in the statewide Environment and Climate Observing Network (ECONet), but with little soils information available for ECONet sites. The objective of this paper is to provide soils data for ECONet development. The authors studied soil physical properties at 27 ECONet sites and generated a database with 13 soil physical parameters, including sand, silt, and clay contents; bulk density; total porosity; saturated hydraulic conductivity; air-dried water content; and water retention at six pressures. Soil properties were highly variable among individual ECONet sites [coefficients of variation (CVs) ranging from 12% to 80%]. This wide range of properties suggests very different behavior among sites with respect to soil moisture. A principal component analysis indicated parameter groupings associated primarily with soil texture, bulk density, and air-dried water content accounted for 80% of the total variance in the dataset. These results suggested that a few specific soil properties could be measured to provide an understanding of differences in sites with respect to major soil properties. The authors also illustrate how the measured soil properties have been used to develop new soil moisture products and data screening for the North Carolina ECONet. The methods, analysis, and results presented here have applications to North Carolina and for other regions with heterogeneous soils where soil moisture monitoring is valuable.



Nature ◽  
1995 ◽  
Vol 373 (6509) ◽  
pp. 49-52 ◽  
Author(s):  
Guohua Chen ◽  
Allan S. Hoffman


1986 ◽  
Vol 23 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Y. Wasti ◽  
M. H. Bezirci

The liquid and plastic limits for a variety of natural and artificial soils covering a wide range of plasticity, as determined by the Casagrande method and the fall cone test and based on a strength criterion, were compared. To check the validity of the strength criterion, the undrained shear strength of these soils has been determined with a laboratory vane over the water content range between these limits. A limited comparison of the undrained strength values obtained from the vane test and fall cone test is also given. Key words: Atterberg limits, consistency, fall cone, laboratory vane, shear strength.



Molecules ◽  
2019 ◽  
Vol 24 (18) ◽  
pp. 3265 ◽  
Author(s):  
Vladimir N. Uversky

Cells are inhomogeneously crowded, possessing a wide range of intracellular liquid droplets abundantly present in the cytoplasm of eukaryotic and bacterial cells, in the mitochondrial matrix and nucleoplasm of eukaryotes, and in the chloroplast’s stroma of plant cells. These proteinaceous membrane-less organelles (PMLOs) not only represent a natural method of intracellular compartmentalization, which is crucial for successful execution of various biological functions, but also serve as important means for the processing of local information and rapid response to the fluctuations in environmental conditions. Since PMLOs, being complex macromolecular assemblages, possess many characteristic features of liquids, they represent highly dynamic (or fuzzy) protein–protein and/or protein–nucleic acid complexes. The biogenesis of PMLOs is controlled by specific intrinsically disordered proteins (IDPs) and hybrid proteins with ordered domains and intrinsically disordered protein regions (IDPRs), which, due to their highly dynamic structures and ability to facilitate multivalent interactions, serve as indispensable drivers of the biological liquid–liquid phase transitions (LLPTs) giving rise to PMLOs. In this article, the importance of the disorder-based supramolecular fuzziness for LLPTs and PMLO biogenesis is discussed.



2019 ◽  
Vol 11 (20) ◽  
pp. 2634-2638 ◽  
Author(s):  
Haijun Yu ◽  
Haoxiang Li ◽  
Chao Chen ◽  
Shengmin Zhou ◽  
Ping Wang

Sensitive and broad range water content detection in organic solvents based on phase transitions of a calcium carbonate nanocomposite is accomplished.



Soil Research ◽  
2012 ◽  
Vol 50 (1) ◽  
pp. 44 ◽  
Author(s):  
M. A. Mojid ◽  
H. Cho

This study explored the effects of water content and temperature on the mobility of exchangeable cations (termed the surface ionic mobility and hereafter ionic mobility) in the hydration layers of bentonite clay. The ionic mobility directly governs the surface conductivity of the clay. The investigation was done by measuring the bulk electrical conductivity (EC) of four sand–bentonite mixtures of different proportions for a wide range of water contents under constant temperature, and three bentonite samples at different water contents over 5–90°C. The ionic mobility was determined from the surface conductivity at the mean ionic strength of the hydration layers. The ionic mobility in the sand–bentonite samples increased with an increase in hydration layer thickness. For a given thickness of the hydration layer, the greater the bentonite content of a sample, the smaller was the ionic mobility. The ionic mobility in the bentonite samples at different water contents also increased, at reduced rates, with a rise in temperature. Consequently, the surface conductivity of the samples increased non-uniformly, at two different rates, with an increase in temperature. The increasing rate of this conductivity depended on temperature; over the low temperature range which depended on the water content, the rate was 0.013 dS/m.K, and over higher temperature range, the rate decreased to 0.008 dS/m.K. The commonly used temperature correction factor, 0.019 dS/m.K, for EC therefore did not hold true for the bentonite samples.



2005 ◽  
Vol 143 (2-3) ◽  
pp. 183-192 ◽  
Author(s):  
F. COSTE ◽  
M. P. RAVENEAU ◽  
Y. CROZAT

A non-destructive indicator of seed water content could significantly help crop scientists with assessment of the effects of environmental conditions during drying on grain qualities or on seed physiological quality. This is particularly important for grain legumes which simultaneously bear pods of different ages. Visual assessment of pod colour has so far been used to date grain legume stages, but now colour can be easily and accurately measured with a portable spectrophotometer. Relationships between the spectrophotometer measurements and the pod and seed water contents were tested in various climatic contexts (3 years: 2000, 2001, 2002; field or greenhouse, two or three sowing dates) for two bean cultivars (Booster and Calypso) and also for one pea cultivar (Baccara) in 2003 near Angers, France. Among the different spectrophotometer measurements, hue angle (h) clearly shows the transition from green (h=180 °) to yellow (h=90 °) and then to red (h=0 °). In each context, h and seed water content (SWC) relationships showed the same pattern of three linear phases: first a steady state; then a sharp decrease from green (h=106–108 °) to yellow (h=85–93 °) just before the end of the seed filling stage for Booster or between the end of the seed filling phase and the beginning of seed drying for Calypso and pea; finally, a slow decrease from yellow to ochre (h=75–78 °) during seed drying. For each bean cultivar, the parameters of the linear relationships showed no differences between maturation conditions. Therefore, 6 h classes matching six SWC classes could be defined over a wide range of SWC between 0·56 and 0·2 g/g for Booster. However for Calypso and pea, only 3 h classes could be defined because of the tight relationships between h and SWC during the end of seed drying, which can be explained by pod walls drying faster than seeds. Hence, spectrophotometer measurements, if calibrated for a given cultivar of a species, could now be used to select pods with seeds of the same water content and therefore to study environmental effects on quality criteria either in controlled conditions or in the field.



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