Preparation and Structural Examinations of Gd+Ni Nanocomposites

2013 ◽  
Vol 203-204 ◽  
pp. 276-279 ◽  
Author(s):  
Marian Kubisztal ◽  
Julian Kubisztal ◽  
Artur Chrobak ◽  
Malgorzata Karolus ◽  
Krystian Prusik ◽  
...  
Keyword(s):  
Low Temperature ◽  
Chemical Reaction ◽  
Curie Point ◽  
Intermediate Layer ◽  
Future Application ◽  
Ni Nanoparticles ◽  
Paramagnetic Component ◽  
Final Layer ◽  
Layer Magnetization

In the paper Gd+Ni nanoparticles were obtained using chemical reaction of Gd nanopowder in the bath based on C4H6O4Ni (pH=7) at temperature 323 K. TEM examinations show Gd+Ni nanoparticles (about 200 nm) covered by GdF3 intermediate layer and Ni-P final layer Magnetization vs. temperature (5-320 K) show the Curie point of Gd at 290 K and at low temperature a paramagnetic component related to GdF3. The obtained Gd+Ni nanopowder of 200 nm in diameter can be used in future application without fear of oxidation.

Using metavisualization to revise an explanatory model regarding a chemical reaction between ions

2021 ◽  
Author(s):  
Solange Wagner Locatelli ◽  
Bette Davidowitz
Keyword(s):  
Undergraduate Students ◽  
Chemical Reaction ◽  
Chemistry Education ◽  
Self Regulation ◽  
Real Life ◽  
Explanatory Models ◽  
Explanatory Model ◽  
Future Application ◽  
Correct Figure ◽  
Real Life Situation

The objective of this work was to evaluate the implementation of a metavisual strategy for students to revise and self-regulate concepts arising in a study of a chemical reaction between ions. For this purpose, two chemistry education undergraduate students at a Brazilian public university carried out an investigative activity, involving metavisual steps, to revise explanatory models at the submicro level. Students were given a problem, namely a reaction between ions drawn from a real-life situation and were provided with clay to construct an explanatory model of the submicro level for the initial and final stages of the reaction. The students were asked to compare their clay model with an example of a scientifically correct figure of the submicro level of the reaction generated by the researchers. At this stage students were given the option to reconstruct their model. Data were captured via photographs of the clay models and students’ verbal discussions as they proceeded through the activity. The findings reveal evidence of self-regulation of mental models at the submicro level, from the interaction of prior knowledge, chemical diagrams and discussions and reflections by the pair of students. Difficulties regarding chemical formulae were also observed in relation to the symbolic level. Finally, there are implications for teaching chemistry, since teachers in training need to experience metavisual strategies for future application in their classrooms.

Sol-Gel Coating Facilitating Si-to-Si Wafer Bonding at Low Temperature

2005 ◽  
Author(s):  
J. Wei ◽  
S. S. Deng ◽  
C. M. Tan
Keyword(s):  
Low Temperature ◽  
Bond Strength ◽  
Wafer Bonding ◽  
Intermediate Layer ◽  
Bonding Temperature ◽  
Sol Gel ◽  
Bond Quality ◽  
Bubble Generation ◽  
High Bond ◽  
High Bond Strength

Silicon-to-silicon wafer bonding by sol-gel intermediate layer has been performed using acid-catalyzed tetraethylthosilicate-ethanol-water sol solution. High bond strength near to the fracture strength of bulk silicon is obtained at low temperature, for example 100°C. However, The bond efficiency and bond strength of this intermediate layer bonding sharply decrease when the bonding temperature increases to elevated temperature, such as 300 °C. The degradation of bond quality is found to be related to the decomposition of residual organic species at elevated bonding temperature. The bubble generation and the mechanism of the high bond strength at low temperature are exploited.

Heat Transfer From Flames Impinging on Flat and Cylindrical Surfaces

1963 ◽  
Vol 85 (1) ◽  
pp. 49-54 ◽  
Author(s):  
J. E. Anderson ◽  
E. F. Stresino
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Low Temperature ◽  
Chemical Reaction ◽  
Heat Transfer Correlation ◽  
Theoretical Reasoning ◽  
Combustion Systems

An experimental investigation was made to determine the heat-transfer distribution obtained when a flame impinges on flat and cylindrical surfaces. The combustion systems studied were oxygen-hydrogen, oxygen-propane, oxygen-acetylene, and air-methane with combustion stream velocities varying from 1 ft/sec to 4600 ft/sec. Data taken with cylindrical heat-transfer surfaces are consistent with available heat-transfer correlation for low temperature gases provided the effect of chemical reaction on the thermal conductivity for flame temperatures above 3500 deg R is taken into consideration. Data taken with flat heat-transfer surfaces can be correlated quite well in a generalized curve partially based on theoretical reasoning.

Basic Experiment on Lithium Removal Technique

2012 ◽  
Author(s):  
Tomohiro Furukawa ◽  
Yasushi Hirakawa
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Dissolution Rate ◽  
Chemical Reaction ◽  
Pure Water ◽  
Preliminary Investigation ◽  
Testing Temperature ◽  
Temperature Range ◽  
Removal Technique ◽  
Good Agreement

As a preliminary investigation into the establishment of a lithium removal technique for the components used at the International Fusion Materials Irradiation Facility (IFMIF), experiments were performed on the dissolution of lithium in three solvents: ethanol, pure water, and ethanol–water. In these experiments, hemispherical lithium was immersed in the solvents at constant temperatures, and the degree of dissolution was measured continuously from the height of the sample. From the obtained data, the average dissolution rate in the solvents at each testing temperature (10–90 °C) and the amount of hydrogen generated by the chemical reaction were calculated. The average dissolution rates in ethanol, pure water, and ethanol–water at 30 °C were 0.01, 1.6, and 0.43 mm/min, respectively. Although the average dissolution rate increased with the testing temperature in the low-temperature range (10–50 °C) for all solvents, this increase was saturated in the high-temperature range (50–90 °C) in experiments with pure water and ethanol–water as solvents. The volume of gas collected during each experiment was in good agreement with the volume of hydrogen assumed to be generated from the chemical reaction of lithium with the solvents.

La-enhanced Ni nanoparticles highly dispersed on SiC for low-temperature CO methanation performance

Rare Metals ◽  
2020 ◽  
Author(s):  
Jiang-Wei Li ◽  
Qi Song ◽  
Jiang-Bing Li ◽  
Sheng-Chao Yang ◽  
Yan-Shan Gao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Ni Nanoparticles ◽  
Co Methanation ◽  
Highly Dispersed

Low temperature deposition of cerium dioxide film by chemical reaction

2001 ◽  
Vol 11 (8) ◽  
pp. 1972-1974 ◽  
Author(s):  
Masanobu Izaki ◽  
Tsutomu Saito ◽  
Masaya Chigane ◽  
Masami Ishikawa ◽  
Jun­ichi Katayama ◽  
...  
Keyword(s):  
Low Temperature ◽  
Chemical Reaction ◽  
Cerium Dioxide ◽  
Low Temperature Deposition ◽  
Temperature Deposition ◽  
Dioxide Film
Sign in / Sign up

Export Citation Format

Share Document