Phase transition and swelling behaviour of different starch granules over a wide range of water content

LWT ◽  
2014 ◽  
Vol 59 (2) ◽  
pp. 597-604 ◽  
Author(s):  
Shujun Wang ◽  
Caili Li ◽  
Jinglin Yu ◽  
Les Copeland ◽  
Shuo Wang
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.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 802
Author(s):  
Suye Li ◽  
Hengqian Wu ◽  
Yanna Zhao ◽  
Ruiyan Zhang ◽  
Zhengping Wang ◽  
...  

The quality control of drug products during manufacturing processes is important, particularly the presence of different polymorphic forms in active pharmaceutical ingredients (APIs) during production, which could affect the performance of the formulated products. The objective of this study was to investigate the phase transformation of fexofenadine hydrochloride (FXD) and its influence on the quality and performance of the drug. Water addition was key controlling factor for the polymorphic conversion from Form I to Form II (hydrate) during the wet granulation process of FXD. Water-induced phase transformation of FXD was studied and quantified with XRD and thermal analysis. When FXD was mixed with water, it rapidly converted to Form II, while the conversion is retarded when FXD is formulated with excipients. In addition, the conversion was totally inhibited when the water content was <15% w/w. The relationship between phase transformation and water content was studied at the small scale, and it was also applicable for the scale-up during wet granulation. The effect of phase transition on the FXD tablet performance was investigated by evaluating granule characterization and dissolution behavior. It was shown that, during the transition, the dissolved FXD acted as a binder to improve the properties of granules, such as density and flowability. However, if the water was over added, it can lead to the incomplete release of the FXD during dissolution. In order to balance the quality attributes and the dissolution of granules, the phase transition of FXD and the water amount added should be controlled during wet granulation.


2013 ◽  
Vol 114 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Paul Malumba ◽  
Nicolas Jacquet ◽  
Guy Delimme ◽  
Florence Lefebvre ◽  
François Béra

2016 ◽  
Vol 4 (43) ◽  
pp. 10279-10285 ◽  
Author(s):  
Qiwu Shi ◽  
Guoqing Chai ◽  
Wanxia Huang ◽  
Yanli Shi ◽  
Bo Huang ◽  
...  

Nanocrystalline λ-Ti3O5was fabricated by carbothermal reduction of nano-TiO2. It exhibits a continuous and slow phase transition across a wide range of temperatures, which can lead to dynamic tuning of THz transmission.


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.


2020 ◽  
Vol 2 (1) ◽  
pp. 37-42
Author(s):  
Arunachalam M ◽  
Thamilmaran P ◽  
Sakthipandi K

Lanthanum calcium based perovskites are found to be advantageous for the possible applications in magnetic sensors/reading heads, cathodes in solid oxide fuel cells, and frequency switching devices. In the present investigation La0.3Ca0.7MnO3 perovskites were synthesised through solid state reaction and sintered at four different temperatures such as 900, 1000, 1100 and 1200˚ C. X-ray powder diffraction pattern confirms that the prepared La0.3Ca0.7MnO3 perovskites have orthorhombic structure with Pnma space group. Ultrasonic in-situ measurements have been carried out on the La0.3Ca0.7MnO3 perovskites over wide range of temperature and elastic constants such as bulk modulus of the prepared La0.3Ca0.7MnO3 perovskites was obtained as function of temperature. The temperature-dependent bulk modulus has shown an interesting anomaly at the metal-insulator phase transition. The metal insulator transition temperature derived from temperature-dependent bulk modulus increases from temperature 352˚ C to 367˚ C with the increase of sintering temperature from 900 to 1200˚ C.


2021 ◽  
Vol 91 (11) ◽  
pp. 1707
Author(s):  
С.А. Кинеловский

For the polymorphic transformation of porous graphite in the shock, the previously proposed model linking the process of graphite phase transition with a change in the elastic energy of a substance has been tested. It is shown that the model plausibly describes the experimental results outside the transition zone in a fairly wide range of changes in the porosity of samples with their different initial structure. It is discussed how the model under consideration changes the currently existing ideas about the thermodynamics of the polymorphic transition of matter in a shock wave.


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.


2002 ◽  
Vol 12 (9) ◽  
pp. 297-301
Author(s):  
K. Miyano ◽  
N. Ogawa

A strong photoinduced suppression of the creep to slide dynamic phase transition was discovered in a quasi one-dimensional CDW material, K0.3MoO3. It is manifested in hysteretic “photoresistivity", an increase in the resistance by orders of magnitude under the illumination of light of modest intensity. Based on a wide range of measurements, it is concluded that the effect is due to the release of the internal stress by photoexcited jumps of the CDW phase over pinning sites: a phenomenon which can be effective only in a system, in which the thermally excited quasiparticles are negligibly small and hence the `bare' CDW properties emerge.


2019 ◽  
Vol 40 ◽  
pp. 73-77
Author(s):  
Bhojraj Bhandari ◽  
Bhadra Prasad Pokheral

Ceramic materials display a wide range of properties that facilitate their use in many different product areas. Currently, there has been keen interest in the field of ceramic materials due to their excellent mechanical and physical properties. Barium Stannate Titanate (BST) is a binary solid solution system composed of ferroelectric Barium titanate and non-ferroelectric barium titanate. In this study, the phase transition behavior of (Ba1-xSnx)TiO3 (x = 0.5) (BST) ceramics  was obtained by the dry-route method. The previous studies were based on Sn 2+ on the Ti site with varying values of x. The powders after calcination are compacted in the form of pellets using a hydraulic press at an optimized load above 70KN. The experimental density of our sample measured by liquid displacement method with glycerin was lower than theoretical density, giving the shape is highly dense with low porosity. The structure shows that on increasing the Sn2+ content volume decreases due to the size of Sn2+, which is smaller than that of Ba2+, in comparison to BaTiO3. As the demand of lead-free environment-friendly sensor is increasing, thus obtained BST has great applications as a sensor material in modern electronic devices.


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