scholarly journals Synthesis of short-range ordered aluminosilicates at ambient conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Katharina R. Lenhardt ◽  
Hergen Breitzke ◽  
Gerd Buntkowsky ◽  
Erik Reimhult ◽  
Max Willinger ◽  
...  
Keyword(s):  
Short Range ◽  
Spatial Arrangement ◽  
Aluminium Chloride ◽  
Ambient Conditions ◽  
Soils And Sediments ◽  
Submicron Scale ◽  
Mineral Structure ◽  
Temperature And Pressure ◽  
Physical And Chemical ◽  
Microscopic Techniques

AbstractWe report here on structure-related aggregation effects of short-range ordered aluminosilicates (SROAS) that have to be considered in the development of synthesis protocols and may be relevant for the properties of SROAS in the environment. We synthesized SROAS of variable composition by neutralizing aqueous aluminium chloride with sodium orthosilicate at ambient temperature and pressure. We determined elemental composition, visualized morphology by microscopic techniques, and resolved mineral structure by solid-state 29Si and 27Al nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Nitrogen sorption revealed substantial surface loss of Al-rich SROAS that resembled proto-imogolite formed in soils and sediments due to aggregation upon freezing. The effect was less pronounced in Si-rich SROAS, indicating a structure-dependent effect on spatial arrangement of mass at the submicron scale. Cryomilling efficiently fractured aggregates but did not change the magnitude of specific surface area. Since accessibility of surface functional groups is a prerequisite for sequestration of substances, elucidating physical and chemical processes of aggregation as a function of composition and crystallinity may improve our understanding of the reactivity of SROAS in the environment.

The Use of Metallography for Examination of Causes of Surface Defects on Visual Parts

2017 ◽  
Vol 270 ◽  
pp. 107-111
Author(s):  
Zuzana Andršová ◽  
Pavel Kejzlar
Keyword(s):  
Sample Preparation ◽  
Cross Section ◽  
Surface Defects ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Visual Appearance ◽  
Visual Defects ◽  
Physical And Chemical ◽  
Microscopic Techniques ◽  
And Chemical Properties

Many of currently manufactured components intended for automotive, must not only meet the requirements on functionality, but also considerable demands on the visual appearance. Parts are subjected to thorough inspection and suppliers are forced to deal with causes of a very slight visual defects. When examining the defects, it is necessary to use a whole range of advanced analytical methods and procedures previously used only for identification of the physical and chemical properties and structure of the material. This paper deals with several examples which have been solved. It focuses especially on the use of demanding metallographic sample preparation from components with surface defects, examining the defects on the cross-section using mainly microscopic techniques and determining the causes of their generation. These results then serve as a basis for modification of the technology and thus they are the tool for significant reduction of amount of NOK parts.

Characteristics of Preheated Bio-Oil Sprays Produced by an Air-Blast Injector

2010 ◽  
Author(s):  
Heena V. Panchasara ◽  
Ajay K. Agrawal
Keyword(s):  
Laser Sheet ◽  
Inlet Temperature ◽  
Mass Ratio ◽  
Ambient Conditions ◽  
Air Blast ◽  
Visualization System ◽  
Radial Profiles ◽  
Significant Difference ◽  
Bio Oil ◽  
Temperature And Pressure

In this study the vegetable oil (VO) is preheated to reduce the kinematic viscosity, and thus, improve atomization. A commercial air-blast atomizer is used to produce the VO spray at ambient conditions of temperature and pressure. Characteristics of the resulting spray are measured using a laser sheet visualization system and a Phase Doppler Particle Analyzer system. Experiments are conducted for VO temperatures varying from 40 C to 100 C and air to liquid mass ratio (ALR) of 2.0 and 4.0. Results show a decrease in Sauter Mean Diameter with an increase in VO temperature, regardless of the ALR. Radial profiles show larger droplets migrating towards the edge of the spray and smaller droplets in the interior spray region. Results show a significant difference in distributions of mean and root mean square axial velocity profiles as the VO inlet temperature is increased for a fixed ALR. Higher VO inlet temperature and higher ALR produced a narrower spray with smaller diameter droplets and higher peak axial velocities. Overall, this study has shown that preheating VO improves atomization by producing spray with smaller diameter droplets.

scholarly journals Facile room temperature synthesis of large graphene sheets from simple molecules

2018 ◽  
Vol 9 (37) ◽  
pp. 7297-7303 ◽  
Author(s):  
Laís C. Lopes ◽  
Lidya C. da Silva ◽  
Boniek G. Vaz ◽  
Alfredo R. M. Oliveira ◽  
Marcela M. Oliveira ◽  
...  
Keyword(s):  
Room Temperature ◽  
Graphene Sheets ◽  
Ambient Conditions ◽  
Temperature Synthesis ◽  
Room Temperature Synthesis ◽  
Temperature And Pressure ◽  
Simple Molecules

The simplest way to produce large graphene sheets starting from simple molecules (benzene or n-hexane) under ambient conditions (temperature and pressure).

scholarly journals Solid-State Characterization and Compatibility Studies of Penciclovir, Lysine Hydrochloride, and Pharmaceutical Excipients

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3154 ◽  
Author(s):  
Rafaela Z. C. Meira ◽  
Isabela F. B. Biscaia ◽  
Camila Nogueira ◽  
Fabio S. Murakami ◽  
Larissa S. Bernardi ◽  
...  
Keyword(s):  
Solid State ◽  
Ethylenediaminetetraacetic Acid ◽  
Therapeutic Potential ◽  
Chemical Characterization ◽  
Compatibility Studies ◽  
Ambient Conditions ◽  
Scanning Calorimetry ◽  
Crystalline Materials ◽  
Physical And Chemical ◽  
Solid State Characterization

The physical and chemical characterization of the solid-state properties of drugs and excipients is fundamental for planning new formulations and developing new strategies for the treatment of diseases. Techniques such as differential scanning calorimetry, thermogravimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy are among the most commonly used techniques for these purposes. Penciclovir and lysine are individually used to treat the herpes virus. As such, the development of a formulation containing both drugs may have therapeutic potential. Solid-state characterization showed that both penciclovir and lysine were crystalline materials with melting points at 278.27 °C and 260.91 °C, respectively. Compatibility studies of penciclovir and lysine indicated a possible interaction between these substances, as evidenced by a single melting point at 253.10 °C. The compatibility of several excipients, including ethylenediaminetetraacetic acid, cetostearyl alcohol, sodium lauryl sulphate, di-tert-butyl methyl phenol, liquid petrolatum, methylparaben, nonionic wax, paraffin, propylene glycol, and propylparaben, was evaluated in ternary (penciclovir-lysine-excipient) mixtures (1:1:1, w/w/w) to determine the optimal formulation. The developed formulation was stable under accelerated and ambient conditions, which demonstrated that the interaction between penciclovir and lysine was suitable for the development of a formulation containing both drugs.

Building metal-functionalized porous carbons from microporous organic polymers for CO2 capture and conversion under ambient conditions

2019 ◽  
Vol 9 (16) ◽  
pp. 4422-4428 ◽  
Author(s):  
Shuai Gu ◽  
Wenguang Yu ◽  
Jingjing Chen ◽  
He Zhang ◽  
Yan Wang ◽  
...  
Keyword(s):  
Co2 Capture ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Organic Polymers ◽  
Porous Carbons ◽  
Ambient Conditions ◽  
Microporous Organic Polymers ◽  
Physical And Chemical ◽  
And Chemical Properties

Metal-functionalized porous carbons derived from microporous organic polymers remain highly desired for their intriguing physical and chemical properties.

Influence of Se on Properties of As-S-Se-I Glass for Immersion Mid-IR Leds Lenses

2019 ◽  
Vol 822 ◽  
pp. 811-817 ◽  
Author(s):  
Margarita G. Dronova ◽  
Artem Osipov
Keyword(s):  
Short Range ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Radiation Characteristics ◽  
Solubility In Water ◽  
Ultrasonic Measurements ◽  
Physical And Chemical ◽  
Short Range Structure ◽  
And Chemical Properties ◽  
Glass Properties

The study of glass components influence on the physical and chemical properties of As–S–Se–I glasses has the potential to help design glasses with the required properties. A change of certain glass properties upon the introduction of selenium into AsSI glass was demonstrated. Non-stoichiometric compounds along the As2S3-AsI3-Se diagram section were investigated by differential thermal analysis, ultrasonic measurements, dilatometric measurements. It has been shown that the introduction of selenium decreases the glass solubility in water. Change in the glass properties with the change in the short-range structure studied by Raman spectroscopy was shown. These glasses can be used for creation of immersion lenses and optical adhesives which change radiation characteristics of mid-IR LEDs.

scholarly journals Physical and chemical characteristics of sapota fruit at different stages of maturation

2002 ◽  
Vol 37 (4) ◽  
pp. 567-572 ◽  
Author(s):  
Edy Sousa de Brito ◽  
Narendra Narain
Keyword(s):  
Storage Time ◽  
Reducing Sugars ◽  
Chemical Characteristics ◽  
Weight Retention ◽  
Ambient Conditions ◽  
Manilkara Zapota ◽  
Post Harvest ◽  
Physical And Chemical Characteristics ◽  
Three Stages ◽  
Physical And Chemical

In the present work, the physical and chemical characteristics in three stages of maturation of sapota (Manilkara zapota L.P. Royen) fruit were studied as well as its post-harvest behavior during storage at ambient and refrigerated conditions. With the advance of maturation, the concentration of the reducing sugars increased while the total acidity and tannin contents decreased. The fruits which did not have their pedicel removed during the post-harvest presented the storage time superior when compared with the fruits having their pedicels removed. The fruits stored under refrigeration had higher weight retention as compared to the fruits stored under ambient conditions.

A Comparison of Air-Blast and Flow-Blurring Injectors Using Phase Doppler Particle Analyzer Technique

2009 ◽  
Author(s):  
Benjamin M. Simmons ◽  
Heena V. Panchasara ◽  
Ajay K. Agrawal
Keyword(s):  
Vegetable Oil ◽  
Laser Sheet ◽  
High Viscosity ◽  
Spray Angle ◽  
Ambient Conditions ◽  
Air Blast ◽  
New Novel ◽  
Significant Difference ◽  
Phase Doppler Particle Analyzer ◽  
Temperature And Pressure

Recent research on biofuels for power generation has typically focused on biodiesel because the biodiesel feedstrock, e.g., vegetable oil, poses significant combustion problems related to poor atomization. Existing injectors cannot effectively atomize high viscosity fuels such as vegetable oil. However, a new, novel flow-blurring (FB) injector concept has shown promise in overcoming the atomization problems. In this study, a FB injector is compared to a commercial air-blast (AB) injector operated with water at ambient conditions of temperature and pressure. Laser sheet visualization and Phase Doppler Particle Analyzer (PDPA) systems are used to obtain the spray characteristics for a range of air to liquid (ALR) ratios. Results show significant difference in distributions of Sauter Mean Diameters (SMDs), and mean and root-mean square axial velocity for the two injectors operated at a fixed ALR. In comparison to the AB injector, the FB injector produced spray with smaller SMDs, a smaller SMD range over the spray volume, higher RMS and mean axial velocities in the center region, and a compact spray with spray angle nearly independent of ALR. Results show that the FB injector is an effective way of atomizing liquids at relatively low ALRs compared to a traditional AB injector, without the additional pressure drop penalty.

IMPACT OF NEUTRON SCATTERING ON THE STUDY OF WATER AND AQUEOUS SOLUTIONS

1993 ◽  
Vol 07 (16n17) ◽  
pp. 3049-3076 ◽  
Author(s):  
A K SOPER ◽  
J TURNER
Keyword(s):  
Neutron Scattering ◽  
Heterogeneous Media ◽  
Pair Correlation ◽  
Water Structure ◽  
Inorganic Ions ◽  
Ambient Conditions ◽  
Deuterium Substitution ◽  
Dissolved Ions ◽  
Physical And Chemical ◽  
The Way

Neutron scattering is making a major impact on our physical and chemical understanding of water structure in aqueous solution. In combination with the technique of isotope substitution it can probe, via the partial pair correlation functions of the system, both the structural aspects of the water itself in solution and the correlation of water molecules with individual dissolved ions and molecules. Moreover it can also investigate the way the solute species distribute themselves in solution. The use of the so-called first-order difference method to look at the hydration of inorganic ions in solution has already been widely reported in several previous reviews, so this account concentrates largely on recent advances in the application of the second order hydrogen-deuterium substitution method to the study of water under non-ambient conditions, and to the measurement of water structure in a variety of solutions and heterogeneous media. It is also shown how the same technique can be used to investigate the nature of solute-solute correlations in solution, and the way water organizes itself around organic molecules and ions in solution.

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