Sol-Gel Synthesis of Protoenstatite

1994 ◽  
Vol 346 ◽  
Author(s):  
Steven A. Jones ◽  
James M. Burlitch
Keyword(s):  
Hydrogen Peroxide ◽  
Freeze Drying ◽  
Room Temperature ◽  
Sol Gel ◽  
Processing Conditions ◽  
Freeze Dried ◽  
Lower Temperature ◽  
Nmr Methods ◽  
Sol Gel Synthesis ◽  
High Temperature Polymorph

ABSTRACTProtoenstatite, a high-temperature polymorph of enstatite (MgSiO3), is generally not stable at room temperature, and is difficult to synthesize. Using a recently developed, hydrogen peroxide-assisted, sol-gel synthesis, protoenstatite was synthesized in a form that was stable at room temperature. Its crystallization was strongly dependent on processing conditions, particularly on the manner in which the xerogel was formed and fired. Xerogels prepared by evaporation, sprav-drying and freeze-drying were compared by XRD, HTXRD, BET, TG/DTA, and 29Si NMR methods. When samples were prepared by evaporation or spray-drying, the result was a mixture of polymorphs. Only the freeze-dried precursor yielded protoenstatite at a lower temperature and within a shorter time than any previously reported.

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

scholarly journals Protective Effects of Tropical Fruit Processing Coproducts on Probiotic Lactobacillus Strains during Freeze-Drying and Storage

2020 ◽  
Vol 8 (1) ◽  
pp. 96 ◽  
Author(s):  
Caroliny Mesquita Araújo ◽  
Karoliny Brito Sampaio ◽  
Francisca Nayara Dantas Duarte Menezes ◽  
Erika Tayse da Cruz Almeida ◽  
Marcos dos Santos Lima ◽  
...  
Keyword(s):  
Membrane Potential ◽  
Freeze Drying ◽  
Room Temperature ◽  
Membrane Integrity ◽  
Added Value ◽  
Protective Effects ◽  
Tropical Fruit ◽  
Freeze Dried ◽  
Fruit Processing ◽  
And Storage

This study evaluated the protective effects of coproducts from agroindustrial processing of the tropical fruits acerola (Malpighia glabra L., ACE), cashew (Anacardium occidentale L., CAS), and guava (Psidium guayaba L., GUA) on the probiotics Lactobacillus paracasei L-10, Lactobacillus casei L-26, and Lactobacillus acidophilus LA-05 during freeze-drying and storage. The occurrence of damage to membrane integrity, membrane potential, and efflux activity of Lactobacillus cells after freeze-drying was evaluated by flow cytometry, and viable counts were measured immediately after freeze-drying and during 90 days of storage under refrigerated or room temperature conditions. Probiotic strains freeze-dried without substrate had the overall highest count reductions (0.5 ± 0.1 to 2.9 ± 0.3 log cycles) after freeze-drying. Probiotics freeze-dried with fruit processing coproducts had small cell subpopulations with damaged efflux activity and membrane potential. Average counts of probiotics freeze-dried with ACE, CAS, or GUA after 90 days of storage under refrigerated or room temperature were in the range of 4.2 ± 0.1 to 5.3 ± 0.2 and 2.6 ± 0.3 to 4.9 ± 0.2 log CFU/g, respectively, which were higher than those observed for strains freeze-dried without substrate. The greatest protective effects on freeze-dried probiotics were overall presented by ACE. These results revealed that ACE, CAS, and GUA can exert protective effects and increase the stability of probiotic lactobacilli during freeze-drying and storage, in addition to supporting a possible added-value destination for these agroindustrial coproducts as vehicles for probiotics and for the development of novel functional foods.

scholarly journals Room Temperature Synthesis of V-Doped TiO2 and Its Photocatalytic Activity in the Removal of Caffeine under UV Irradiation

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 911 ◽  
Author(s):  
Olga Sacco ◽  
Diana Sannino ◽  
Mariantonietta Matarangolo ◽  
Vincenzo Vaiano
Keyword(s):  
Room Temperature ◽  
Uv Light ◽  
Sol Gel ◽  
Doped Tio2 ◽  
Toc Removal ◽  
Calcination Step ◽  
Caffeine Degradation ◽  
Wavelength Emission ◽  
Sol Gel Synthesis ◽  
Uv Leds

In this work, the influence of simple acids in the room temperature sol-gel synthesis of TiO2 was investigated and the efficiency of prepared photocatalysts was evaluated in the removal of caffeine. To improve the photoactivity of TiO2, vanadium-doped TiO2 (VTiO2) samples were obtained starting from different amount of vanadyl sulphate as a dopant source. The samples were centrifuged, washed and finally dried at room temperature, and no calcination step was carried out. The prepared photocatalysts were characterized by different techniques (X-ray powder diffraction (XRD), specific surface area (SSA), ultraviolet-visible diffuse reflectance spectra (UV-vis DRS) and Raman). VTiO2 photocatalysts were tested in the photocatalytic removal of aqueous solutions containing caffeine. The photocatalytic tests were carried out in a recirculating batch cylindrical photoreactor irradiated by a UV LEDs strip (nominal power of 12 W and wavelength emission peak at about 365 nm) surrounding the external surface of the reactor. The optimized VTiO2 photocatalyst was able to reach a caffeine degradation of about 96% after 360 min of UV light irradiation with a total organic carbon (TOC) removal of 72%.

Effect of autoclaving and cooling on resistant starch formation in rice starch

2016 ◽  
Vol 35 (2) ◽  
Author(s):  
Lilia-Baby ◽  
K. T. Suman ◽  
S. Krishnan ◽  
V. Indira
Keyword(s):  
Resistant Starch ◽  
Room Temperature ◽  
Rice Starch ◽  
Processing Conditions ◽  
Single Factor ◽  
Multiple Factors ◽  
Cent Moisture ◽  
Cooling Conditions ◽  
Lower Temperature ◽  
Starch Formation

A study was undertaken to standardise processing treatments for optimising resistant starch (RS) formation in rice starch. The effect of processing conditions on the RS content of rice starch was studied in 48 treatments by autoclaving at 121°C and 141°C for 20, 40 and 60 minutes without moisture and with 10, 20 and 40 percentage moisture levels. After autoclaving, the samples were cooled at room temperature and at -20°C. The yield of RS was found to be maximum in samples autoclaved at 141°C for 40 minutes with 10 per cent moisture and cooled at -20°C. Increasing the duration of autoclaving up to 60 minutes at a lower temperature of 121°C was also found to be effective in improving the RS content of rice starch. RS formation not only depends on a single factor but also on multiple factors like time and temperature of autoclaving, moisture as well as cooling conditions.

scholarly journals Nanoscale CaF2 doped with Eu3+ and Tb3+ through fluorolytic sol–gel synthesis

2014 ◽  
Vol 2 (40) ◽  
pp. 8607-8613 ◽  
Author(s):  
Benjamin Ritter ◽  
Thoralf Krahl ◽  
Knut Rurack ◽  
Erhard Kemnitz
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Synthesis Method ◽  
One Pot ◽  
One Pot Synthesis ◽  
Sol Gel Synthesis

Easy upscaleable one-pot synthesis method at room temperature for ultra small sized Eu3+- and Tb3+-doped CaF2 nanoparticles.

Chemical Processing and Properties of Nanocrystalline BaTiO3

1992 ◽  
Vol 271 ◽  
Author(s):  
Z. Xu ◽  
H. K. Chae ◽  
M. H. Frey ◽  
D. A. Payne
Keyword(s):  
Grain Size ◽  
Thermal Processing ◽  
Room Temperature ◽  
Sol Gel ◽  
Thin Layers ◽  
Silicon Substrates ◽  
Chemical Processing ◽  
Temperature Structure ◽  
Processing Conditions ◽  
Gel Processing

ABSTRACTBarium titanate (BaTiO3) thin layers were prepared by sol-gel processing. Details are reported for the synthesis route from methoxyethoxide precursors. Partially hydrolyzed solutions were spin-cast onto metallized silicon substrates, and a multilayering technique was used to develop sub-micron structures. Information is reported on the thermal processing conditions used and the development of structure. Crystallization started at 600°C and was fully developed by 700°C. The room temperature structure was cubic, and the grain size was 25–50 nm. Details are reported for the dielectric properties. Ferroelectricity was not observed. Dielectric constant (200–300) increased with increasing grain size, and was stable with respect to temperature, field and frequency. The properties are attractive for potential integrated capacitor applications.

scholarly journals Sol–gel synthesis and room-temperature properties of α-LiZr2(PO4)3

RSC Advances ◽  
2015 ◽  
Vol 5 (22) ◽  
pp. 17054-17059 ◽  
Author(s):  
Hany El-Shinawi ◽  
Colin Greaves ◽  
Jürgen Janek
Keyword(s):  
Room Temperature ◽  
Sol Gel ◽  
Bulk Conductivity ◽  
Gel Method ◽  
Sol Gel Method ◽  
Sol Gel Synthesis

A room-temperature stable α-LiZr2(PO4)3 phase is prepared by a modified sol–gel method, and shows bulk conductivity as high as 1.58 × 10−4 Scm−1.

The effect of heat on the vitamin B6 of milk: II. A comparison of biological and microbiological tests of evaporated milk

1959 ◽  
Vol 26 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Mary K. Davies ◽  
Margaret E. Gregory ◽  
Kathleen M. Henry
Keyword(s):  
Vitamin B6 ◽  
Experimental Error ◽  
Freeze Drying ◽  
Room Temperature ◽  
Raw Milk ◽  
Vitamin B ◽  
Experimental Conditions ◽  
Freeze Dried ◽  
Microbiological Research ◽  
Chick Diet

1. For chicks and rats pyridoxine, pyridoxal and pyridoxamine were equally active in terms of the free bases when given separately from the diet.2. Under our experimental conditions pyridoxine mixed with the chick diet was stable, but 20% of pyridoxamine, and a variable amount of pyridoxal was lost.3. The vitamin B6 activities measured with Saccharomyces carlsbergensis, chicks and rats respectively and expressed as μg. pyridoxine/g. freeze-dried milk were: raw milk 3·4, 3·2 and 4·9; evaporated milk 1·0, 2·1 and 2·7; stored evaporated milk 0·6, 1·4 and 2·0. For the chicks the milks were mixed with the diets; they were given separately to the rats.4. The microbiological and biological results for raw milk agreed within the limits of experimental error. For the processed milks the differences between biological and microbiological tests were statistically significant.5. All three methods of assay showed a 45–70% loss of vitamin B6 activity on processing and a further loss of 30% of the remainder after storage for 6 months at room temperature.We are indebted to Mr J. Rothwell, Department of Dairying, University of Reading, for preparing the evaporated milk and to Dr B. Record, Ministry of Supply, Microbiological Research Establishment, Porton, for freeze-drying the milk. We should like to thank Dr S. K. Kon for his interest in this work.

The effects of surfactant in the sol–gel synthesis of CuO/TiO2 nanocomposites on its photocatalytic activities under UV-visible and visible light illuminations

2020 ◽  
Vol 44 (5) ◽  
pp. 1888-1904 ◽  
Author(s):  
T. N. Ravishankar ◽  
M. de O. Vaz ◽  
S. R. Teixeira
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Low Cost ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Photocatalytic Activities ◽  
Uv Visible ◽  
Sol Gel Synthesis ◽  
Surfactant Assisted

Effective and low-cost CuO/TiO2 nanocomposites were prepared at room temperature by a surfactant-assisted sol–gel method for photocatalytic activities under UV-visible and visible light irradiations.

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