scholarly journals The Deterioration Mechanism of Diester Aero Lubricating Oil at High Temperature

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Ting Yao ◽  
Hongwei Yang ◽  
Li Guo ◽  
Yiwei Fei ◽  
Huize Jiang ◽  
...  
Keyword(s):  
High Temperature ◽  
Physicochemical Properties ◽  
High Temperatures ◽  
Mass Spectrometer ◽  
Operating Conditions ◽  
Lubricating Oil ◽  
Gas Chromatograph ◽  
Thermal Pyrolysis ◽  
Specific Device ◽  
Deterioration Mechanism

The deterioration of aero lubricating oil at high temperatures was accelerated by using a specific device simulating the operating conditions of engines, where the deterioration mechanism was obtained. Structures of the deteriorated lubricating oils were analyzed by gas chromatograph/mass spectrometer. From the results, it can be concluded that deterioration of aero lubricating oil at high temperatures was composed of thermal pyrolysis, oxidation, and polymerization, with the generation of a variety of products, such as alcohols, aldehydes, acids, and esters, which caused the deterioration of physicochemical properties of the aero lubricating oil.

HASTELLOY ALLOY X

Alloy Digest ◽  
1954 ◽  
Vol 3 (12) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
High Temperatures ◽  
Heat Treating ◽  
Operating Conditions ◽  
Molybdenum Alloy ◽  
High Temperature Strength ◽  
Nickel Chromium

Abstract HASTELLOY Alloy X is a nickel-chromium-iron-molybdenum alloy recommended for high-temperature applications. It has outstanding oxidation resistance at high temperatures under most operating conditions, and good high-temperature strength. This datasheet provides information on composition, physical properties, and tensile properties as well as creep. It also includes information on forming, heat treating, and machining. Filing Code: Ni-14. Producer or source: Haynes Stellite Company.

Remotely operated high temperature vent valve for a gas chromatograph/mass spectrometer

1972 ◽  
Vol 44 (7) ◽  
pp. 1332-1334 ◽  
Author(s):  
J. P. Mieure ◽  
J. G. Converse ◽  
M. W. Dietrich ◽  
Lewis. Fowler
Keyword(s):  
High Temperature ◽  
Mass Spectrometer ◽  
Gas Chromatograph ◽  
Vent Valve

scholarly journals A Novel Ground-Source Heat Pump with R744 and R1234ze as Refrigerants

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5654
Author(s):  
Giuseppe Emmi ◽  
Sara Bordignon ◽  
Laura Carnieletto ◽  
Michele De Carli ◽  
Fabio Poletto ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Pump ◽  
High Temperatures ◽  
Real Data ◽  
Energy Performance ◽  
Operating Conditions ◽  
Two Stage ◽  
Carrier Fluid ◽  
Ground Source ◽  
Novel Concept

The energy-saving potential of heat pump technology is widely recognized in the building sector. In retrofit applications, especially in old and historic buildings, it may be difficult to replace the existing distribution and high-temperature emission systems. Often, historical buildings, especially the listed ones, cannot be thermally insulated; this leads to high temperatures of the heat carrier fluid for heating. In these cases, the main limits are related, on the one hand, to the reaching of the required temperatures, and on the other hand, to the obtaining of good performance even at high temperatures. To address these problems, a suitable solution can be a two-stage heat pump. In this work, a novel concept of a two-stage heat pump is proposed, based on a transcritical cycle that uses the natural fluid R744 (carbon dioxide) with an ejector system. The second refrigerant present in the heat pump and used for the high-temperature stage is the R1234ze, which is an HFO (hydrofluoro-olefin) fluid. This work aims to present the effective energy performance based on real data obtained in operating conditions in a monitoring campaign. The heat pump prototype used in this application is part of the H2020 Cheap-GSHP project, which was concluded in 2019.

scholarly journals KOH-Based Modified Solvay Process for Removing Na Ions from High Salinity Reject Brine at High Temperatures

2021 ◽  
Vol 13 (18) ◽  
pp. 10200
Author(s):  
Aya A-H. I. Mourad ◽  
Ameera F. Mohammad ◽  
Ali H. Al-Marzouqi ◽  
Muftah H. El-Naas ◽  
Mohamed H. Al-Marzouqi ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Operating Conditions ◽  
Co2 Uptake ◽  
Ion Removal ◽  
Solvay Process ◽  
Carbon Dioxide Co2 ◽  
Desalination Plants ◽  
The Impact ◽  
Brine Salinity

The traditional Solvay process and other modifications that are based on different types of alkaline material and waste promise to be effective in the reduction of reject brine salinity and the capture of CO2. These processes, however, require low temperatures (10–20 °C) to increase the solubility of CO2 and enhance the precipitation of metallic salts, while reject brine is usually discharged from desalination plants at relatively high temperatures (40–55 °C). A modified Solvay process based on potassium hydroxide (KOH) has emerged as a promising technique for simultaneously capturing carbon dioxide (CO2) and reducing ions from reject brine in a combined reaction. In this study, the ability of the KOH-based Solvay process to reduce brine salinity at relatively high temperatures was investigated. The impact of different operating conditions, including pressure, KOH concentration, temperature, and CO2 gas flowrate, on CO2 uptake and ion removal was investigated and optimized. The optimization was performed using the response surface methodology based on a central composite design. A CO2 uptake of 0.50 g CO2/g KOH and maximum removal rates of sodium (Na+), chloride (Cl−), calcium (Ca2+), and magnesium (Mg2+) of 45.6%, 29.8%, 100%, and 91.2%, respectively, were obtained at a gauge pressure, gas flowrate, and KOH concentration of 2 bar, 776 mL/min, and 30 g/L, respectively, and at high temperature of 50 °C. These results confirm the effectiveness of the process in salinity reduction at a relatively high temperature that is near the actual reject brine temperature without prior cooling. The structural and chemical characteristics of the produced solids were investigated, confirming the presence of valuable products such as sodium bicarbonate (NaHCO3), potassium bicarbonate (KHCO3) and potassium chloride (KCl).

scholarly journals Prospects of nanotechnology and materials design on the basis of refractory compounds

2018 ◽  
pp. 73-81
Author(s):  
I. L. Shabalin
Keyword(s):  
High Temperature ◽  
Physicochemical Properties ◽  
High Temperatures ◽  
Materials Science ◽  
Ceramic Materials ◽  
Materials Design ◽  
Ceramic Composites ◽  
Engineering Practice ◽  
Refractory Compounds ◽  
Similar Materials

As a matter of discussion, the prospects for the development of high-temperature ceramic materials science are considered. The paper provides a rationale for developing hetero-modulus ceramic composites as a possibility to implement the unique physicochemical properties of refractory compounds (carbides, nitrides, borides, etc.) under the conditions of their application at high and ultra-high temperatures. The prospects of nanotechnology-based approach to the preparation of similar materials in engineering practice are shown.

Automatic high temperature vent system for a gas chromatograph/mass spectrometer interface

1974 ◽  
Vol 46 (6) ◽  
pp. 804-805 ◽  
Author(s):  
Douglas W. Kuehl ◽  
Gary E. Glass ◽  
Frank A. Puglisi
Keyword(s):  
High Temperature ◽  
Mass Spectrometer ◽  
Gas Chromatograph

High Temperature n- and p-type Doped Microcrystalline Silicon Layers Grown by VHF PECVD Layer-by-Layer Deposition

2003 ◽  
Vol 762 ◽  
Author(s):  
A. Gordijn ◽  
J.K. Rath ◽  
R.E.I. Schropp
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
High Temperatures ◽  
Continuous Wave ◽  
Hydrogen Plasma ◽  
Silicon Layer ◽  
Dark Conductivity ◽  
High Deposition Rate ◽  
Layer By Layer ◽  
Microcrystalline Silicon

AbstractDue to the high temperatures used for high deposition rate microcrystalline (μc-Si:H) and polycrystalline silicon, there is a need for compact and temperature-stable doped layers. In this study we report on films grown by the layer-by-layer method (LbL) using VHF PECVD. Growth of an amorphous silicon layer is alternated by a hydrogen plasma treatment. In LbL, the surface reactions are separated time-wise from the nucleation in the bulk. We observed that it is possible to incorporate dopant atoms in the layer, without disturbing the nucleation. Even at high substrate temperatures (up to 400°C) doped layers can be made microcrystalline. At these temperatures, in the continuous wave case, crystallinity is hindered, which is generally attributed to the out-diffusion of hydrogen from the surface and the presence of impurities (dopants).We observe that the parameter window for the treatment time for p-layers is smaller compared to n-layers. Moreover we observe that for high temperatures, the nucleation of p-layers is more adversely affected than for n-layers. Thin, doped layers have been structurally, optically and electrically characterized. The best n-layer made at 400°C, with a thickness of only 31 nm, had an activation energy of 0.056 eV and a dark conductivity of 2.7 S/cm, while the best p-layer made at 350°C, with a thickness of 29 nm, had an activation energy of 0.11 V and a dark conductivity of 0.1 S/cm. The suitability of these high temperature n-layers has been demonstrated in an n-i-p microcrystalline silicon solar cell with an unoptimized μc-Si:H i-layer deposited at 250°C and without buffer. The Voc of the cell is 0.48 V and the fill factor is 70 %.

Trends in the development of flexible thermal protection systems for modern aircraft

2020 ◽  
pp. 10-21
Author(s):  
V. G. Babashov ◽  
◽  
N. M. Varrik ◽  
Keyword(s):  
High Temperature ◽  
Thermal Protection ◽  
Heat Removal ◽  
Operating Conditions ◽  
Passive Protection ◽  
Thermal Protection Systems ◽  
Heat Protection ◽  
Protection Systems ◽  
Protected Surface ◽  
Flexible Panels

The emergence of new types of space and aviation technology necessitates the development of new types of thermal protection systems capable of operating at high temperature and long operating times. There are several types of thermal protection systems for different operating conditions: active thermal protection systems using forced supply of coolant to the protected surface, passive thermal protection systems using materials with low thermal conductivity without additional heat removal, high-temperature systems, which are simultaneously elements of the bearing structure and provide thermal protection, ablation materials. Heat protection systems in the form of rigid tiles and flexible panels, felt and mats are most common kind of heat protecting systems. This article examines the trends of development of flexible reusable heat protection systems intended for passive protection of aircraft structural structures from overheating.

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