scholarly journals Solubility Study of Nickel Ferrite in Boric Acid Using a Flow-Through Autoclave System under High Temperature and High Pressure

2016 ◽  
Vol 48 (2) ◽  
pp. 554-558 ◽  
Author(s):  
Yong Joon Park ◽  
Ke-Chon Choi ◽  
Yeong-Keong Ha
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Boric Acid ◽  
Nickel Ferrite ◽  
Solubility Study ◽  
Flow Through

Study on Nickel Ferrite Formation by Using a Simple Method to Simulate Heat Transfer Surface

2007 ◽  
Vol 124-126 ◽  
pp. 1565-1568 ◽  
Author(s):  
Jei Won Yeon ◽  
Kwang Soon Choi ◽  
Yongju Jung ◽  
Selvaraj Rengaraj ◽  
Yeong Keong Ha ◽  
...  
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
High Temperature ◽  
Nickel Ferrite ◽  
Energy Difference ◽  
Heat Transfer Surface ◽  
Simple Method ◽  
Ft Ir ◽  
Thermodynamic Relationship ◽  
Relationship Of

The condition of a heat transfer surface with boiling is composed of three environmental components; high temperature, high pressure and water vapor. In general an autoclave or a high temperature loop system is used for maintaining the required condition. The thermodynamic relationship of chemical reactions states that the free energy difference (ΔG) is clearly dependent on the reaction temperature and independent of the reaction pressure if the reaction has no volume change: (∂ΔG/∂P)T = ΔV ~ 0. Based on the above relationship, the high-pressure term was removed from the environmental components of the heat transfer surface. A vacuum quartz capsule with a moisturized metal oxide powder was used to study the formation of nickel ferrite. The feasibility of this simplified method to simulate a heat transfer surface was confirmed by an analysis of the FT-IR spectra and XRD pattern during the transformation of a nickel and iron mixed oxide into nickel ferrite.

Solubility Study of Magnetite under Extreme High Pressure and High Temperature

2014 ◽  
Author(s):  
C. Yan ◽  
P. Guraieb ◽  
J. Huang ◽  
E. Contreras ◽  
R. C. Tomson ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Solubility Study

Practical and "Unusual" Applications in X-ray Diffraction Using Position Sensitive Detectors

1990 ◽  
Vol 34 ◽  
pp. 349-355
Author(s):  
Ralph G. Tissot ◽  
Michael O. Eatough
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flow Through ◽  
Position Sensitive ◽  
Short Time ◽  
Position Sensitive Detectors ◽  
Time Frames

AbstractPosition sensitive proportional counters (PSPCs) increase the scope of X-ray diffraction analyses. High pressure flow through type PSPCs can significantly reduce data collecting times due to She ability for simultaneous data collection over large two-theta ranges. This inherent characteristic allows the diffraction user broad capabilities such as scanning very rapidly over large two- theta ranges or collecting data in real time over shorter two-theta ranges without scanning. Thus, we have been able to perform detailed high- temperature experiments in relatively short time frames, observe phase transitions and reactions as they occur, and perform unusual experiments such as observing the crystallization of a plasma spray in-situ.

scholarly journals Single-pass flow-through reaction cell for high-temperature and high-pressurein situneutron diffraction studies of hydrothermal crystallization processes

2012 ◽  
Vol 45 (2) ◽  
pp. 166-173 ◽  
Author(s):  
Fang Xia ◽  
Joël Brugger ◽  
Gujie Qian ◽  
Yung Ngothai ◽  
Brian O'Neill ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Flow Rate ◽  
Room Temperature ◽  
Ambient Pressure ◽  
Vacuum Furnace ◽  
Hydrothermal Crystallization ◽  
Single Pass ◽  
Flow Through

A large-volume single-pass flow-through cell forin situneutron diffraction investigation of hydrothermal crystallization processes is reported. The cell is much more versatile than previous designs owing to the ability to control independently and precisely temperature (up to 673 K), pressure (up to 46 MPa), flow rate (0.01–10 ml min−1) and reaction-fluid volume (≥65 ml). Such versatility is realized by an innovative design consisting of a room-temperature and ambient-pressure external fluid supply module, a high-pressure reaction module which includes a high-temperature sample compartment enclosed in a vacuum furnace, and a room-temperature and high-pressure backpressure regulation module for pressure control. The cell provides a new avenue for studying various parameters of hydrothermal crystallizations independently,in situand in real time at extreme hydrothermal conditions (e.g.supercritical). The cell was successfully commissioned on the high-intensity powder diffractometer beamline, Wombat, at the Australian Nuclear Science and Technology Organisation by investigating the effect of pressure on the hydrothermal pseudomorphic conversion from SrSO4(celestine) to SrCO3(strontianite) at a constant temperature of 473 K and flow rate of 5 ml min−1. The results show that the increase of pressure exerts a nonlinear effect on the conversion rate, which first increases with increasing pressure from 14 to 20 MPa, and then decreases when pressure further increases to 24 MPa.

Microstructural Study of Diamond Deformed Under High Pressure and Temperature

1985 ◽  
Vol 43 ◽  
pp. 230-231
Author(s):  
E. F. Koch
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Lattice Structure ◽  
Diamond Particle ◽  
Polycrystalline Diamond ◽  
Sintering Process ◽  
Ion Milling ◽  
Sintered Compact ◽  
Transmission Electron ◽  
High Pressure Sintering

Because of the extremely rigid lattice structure of diamond, generating new dislocations or moving existing dislocations in diamond by applying mechanical stress at ambient temperature is very difficult. Analysis of portions of diamonds deformed under bending stress at elevated temperature has shown that diamond deforms plastically under suitable conditions and that its primary slip systems are on the ﹛111﹜ planes. Plastic deformation in diamond is more commonly observed during the high temperature - high pressure sintering process used to make diamond compacts. The pressure and temperature conditions in the sintering presses are sufficiently high that many diamond grains in the sintered compact show deformed microtructures.In this report commercially available polycrystalline diamond discs for rock cutting applications were analyzed to study the deformation substructures in the diamond grains using transmission electron microscopy. An individual diamond particle can be plastically deformed in a high pressure apparatus at high temperature, but it is nearly impossible to prepare such a particle for TEM observation, since any medium in which the diamond is mounted wears away faster than the diamond during ion milling and the diamond is lost.

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