Stimulated Desorption as a Potential Damage Mechanism in Ultraviolet Laser Optical Components

1985 ◽  
pp. 277-280
Author(s):  
Richard Haglund ◽  
Norman Tolk
Keyword(s):  
Damage Mechanism ◽  
Optical Components ◽  
Ultraviolet Laser ◽  
Potential Damage

scholarly journals Damage Mechanism of Oil-Based Drilling Fluid Flow in Seepage Channels for Fractured Tight Sandstone Gas Reservoirs

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Peng Xu ◽  
Mingbiao Xu
Keyword(s):  
Drilling Fluid ◽  
Damage Control ◽  
Damage Mechanism ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Stabilization Effect ◽  
Potential Damage ◽  
Physical And Chemical

Oil-based drilling fluids (OBDFs) have a strong wellbore stabilization effect, but little attention has been paid to the formation damage caused by oil-based drilling fluids based on traditional knowledge, which is a problem that must be solved prior to the application of oil-based drilling fluid. For ultradeep fractured tight sandstone gas reservoirs, the reservoir damage caused by oil-based drilling fluids is worthy of additional research. In this paper, the potential damage factors of oil-based drilling fluids and fractured tight sandstone formations are analyzed theoretically and experimentally. The damage mechanism of oil-based drilling fluids for fractured tight sandstone gas reservoirs is analyzed based on the characteristics of multiphase fluids in seepage channels, the physical and chemical changes of rocks, and the rheological stability of oil-based drilling fluids. Based on the damage mechanism of oil-based drilling fluids, the key problems that must be solved during the damage control of oil-based drilling fluids are analyzed, a detailed description of formation damage characteristics is made, and how to accurately and rapidly form plugging zones is addressed. This research on damage control can provide a reference for solving the damage problems caused by oil-based drilling fluids in fractured tight sandstone gas reservoirs.

Life-Cycle Management of Pressurized Fixed Equipment

2011 ◽  
Author(s):  
David A. Osage ◽  
David R. Thornton ◽  
Philip A. Henry
Keyword(s):  
Life Cycle ◽  
Damage Mechanism ◽  
Life Cycle Management ◽  
Remaining Life ◽  
Analysis Techniques ◽  
Design Life ◽  
Process Plants ◽  
Integrate Technology ◽  
Potential Damage ◽  
Service Inspection

Many process plants will continue to operate pressurized equipment well beyond its intended design life. To ensure that the equipment operates safely and reliably requires adoption of an equipment Life-Cycle Management (LCM) process. During equipment design the LCM process requires identification of potential damage mechanisms, and a design that resists or mitigates the damage. For equipment that has been put into operation the LCM process continues with the use of prescriptive or Risk-Based inspection. An evaluation of the in-service inspection results reveals whether any anticipated (i.e., was considered in the initial design) or unanticipated damage has occurred. If the damage is anticipated and within the design limits, the equipment is returned to operation for a period of time that considers the equipment remaining life, with a new inspection at the end of the operational period. If unanticipated damage is discovered the LCM process requires identification of the damage mechanism and a subsequent Fitness-For-Service assessment to facilitate a decision to run as is, or to rerate, repair, or to replace the damaged components. To effectively implement the LCM approach, codes and standards must exist that address each aspect of the process. In addition, ensuring that similar analysis techniques are employed at the time of construction and when conducting in-service assessments requires coordination of the technology integration in these codes and standards. An overview of API, ASME, and other codes and standards is provided together with a discussion of the efforts to integrate technology to support the LCM process.

scholarly journals Study on Reservoir Geological Characteristics and Potential Damage Mechanism of FIOC Oilfield in Sargiz

2020 ◽  
Vol 05 (01) ◽  
pp. 26-34
Author(s):  
Dichen Tan ◽  
Zhu Zhu ◽  
Huaiyuan Long ◽  
Song Wang ◽  
Haoren Wang
Keyword(s):  
Damage Mechanism ◽  
Geological Characteristics ◽  
Potential Damage

The Study of Inspection and Supervision for Overage Service Pressure Vessels in Petrochemical Plants

2019 ◽  
Vol 795 ◽  
pp. 346-351
Author(s):  
Jun Si ◽  
Jin Sha Xu ◽  
Yu Qing Yang ◽  
Xiang Wen ◽  
Xiao Ying Tang
Keyword(s):  
Service Life ◽  
Risk Evaluation ◽  
Damage Mechanism ◽  
Evaluation Methods ◽  
Pressure Vessels ◽  
Basic Theory ◽  
Basic Principles ◽  
Integrity Assessment ◽  
Potential Damage ◽  
Risk Supervision

Overage service pressure vessels are widespread in China. These pressure vessels may be suffered from some forms of material deterioration and damage with an increasing possibility of failure. However, some of the potential damage mechanism couldn’t be found if the inspection strategies were carried out in according with traditional inspection regulations. Through identifying the damage mechanism of these pressure vessels, the risk evaluation would be carried out by use of RBI technology in company with the structure integrity assessment. The procedure of inspection for overage service pressure vessels was developed, and some of the reasonable inspection and testing requirements and basic principles also were proposed. The three levels evaluation methods of residual safe-service life for these pressure vessels were proposed. At the same time, the risk supervision method of these pressure vessels was established by use on the risk basic theory.

A potential damage mechanism of rubberized cement under freeze-thaw cycle

2020 ◽  
Vol 252 ◽  
pp. 119054
Author(s):  
Linxin Hua ◽  
Feipeng Xiao ◽  
Yitao Li ◽  
Hongbin Huang ◽  
Kewei Zhao ◽  
...  
Keyword(s):  
Damage Mechanism ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Potential Damage

Preparation of Thin Cadmium Telluride Samples for Electron Microscope Studies

1974 ◽  
Vol 32 ◽  
pp. 548-549
Author(s):  
T. J. Magee ◽  
J. Peng ◽  
J. Bean
Keyword(s):  
Electron Microscope ◽  
Sulfuric Acid ◽  
Solid State ◽  
Sample Preparation ◽  
Cadmium Telluride ◽  
Potassium Dichromate ◽  
Optical Components ◽  
The Past ◽  
Solid State Devices

Cadmium telluride has become increasingly important in a number of technological applications, particularly in the area of laser-optical components and solid state devices, Microstructural characterizations of the material have in the past been somewhat limited because of the lack of suitable sample preparation and thinning techniques. Utilizing a modified jet thinning apparatus and a potassium dichromate-sulfuric acid thinning solution, a procedure has now been developed for obtaining thin contamination-free samples for TEM examination.

Ultrastructural Changes in Three Different Mammalian Cells Following Ultraviolet Laser Irradiation

1972 ◽  
Vol 30 ◽  
pp. 350-351
Author(s):  
K. Shankar Narayan ◽  
Kailash C. Gupta ◽  
Tohru Okigaki
Keyword(s):  
Ultraviolet Light ◽  
Mammalian Cells ◽  
Biological Effects ◽  
Survival Rates ◽  
Chinese Hamster ◽  
Cell Types ◽  
Differential Sensitivity ◽  
Ultrastructural Changes ◽  
Ultraviolet Laser

The biological effects of short-wave ultraviolet light has generally been described in terms of changes in cell growth or survival rates and production of chromosomal aberrations. Ultrastructural changes following exposure of cells to ultraviolet light, particularly at 265 nm, have not been reported.We have developed a means of irradiating populations of cells grown in vitro to a monochromatic ultraviolet laser beam at a wavelength of 265 nm based on the method of Johnson. The cell types studies were: i) WI-38, a human diploid fibroblast; ii) CMP, a human adenocarcinoma cell line; and iii) Don C-II, a Chinese hamster fibroblast cell strain. The cells were exposed either in situ or in suspension to the ultraviolet laser (UVL) beam. Irradiated cell populations were studied either "immediately" or following growth for 1-8 days after irradiation.Differential sensitivity, as measured by survival rates were observed in the three cell types studied. Pattern of ultrastructural changes were also different in the three cell types.

Elemental mass loss in silicate minerals during x-ray analysis

1990 ◽  
Vol 48 (4) ◽  
pp. 804-805
Author(s):  
P.E. Champness ◽  
R.W. Devenish
Keyword(s):  
Mass Loss ◽  
Current Density ◽  
Damage Mechanism ◽  
Beam Current ◽  
Single Chain ◽  
Plagioclase Feldspar ◽  
X Ray ◽  
Alkali Ions ◽  
Structural Order ◽  
Sheet Silicate

It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during electron irradiation at 100 kV over a range of current densities of 104 - 109 A m−2. (The current density is defined in terms of 50% of total current in the FWHM probe). The silicates so far ivestigated are:- olivine [(Mg, Fe)SiO4], a structure that has isolated Si-O tetrahedra, garnet [(Mg, Ca, Fe)3Al2Si3AO12 another silicate with isolated tetrahedra, pyroxene [-Ca(Mg, Fe)Si2O6 a single-chain silicate; mica [margarite, -Ca2Al4Si4Al4O2O(OH)4], a sheet silicate, and plagioclase feldspar [-NaCaAl3Si5O16]. Ion- thinned samples of each mineral were examined in a VG Microscopes UHV HB501 field- emission STEM. The beam current used was typically - 0.5 nA and the current density was varied by defocussing the electron probe. Energy-dispersive X-ray spectra were collected every 10 seconds for a total of 200 seconds using a Link Systems windowless detector. The thickness of the samples in the area of analysis was normally 50-150 nm.

Damage Risk: An Evaluation of the Effects of Exposure to 85 versus 90 dBA of Noise

1976 ◽  
Vol 19 (2) ◽  
pp. 216-224 ◽  
Author(s):  
James T. Yates ◽  
Jerry D. Ramsey ◽  
Jay W. Holland
Keyword(s):  
White Noise ◽  
Statistical Difference ◽  
Noise Exposure ◽  
Threshold Shift ◽  
Temporary Threshold Shift ◽  
Noise Levels ◽  
Potential Damage ◽  
Full Day ◽  
Damage Risk

The purpose of this study was to compare the damage risk of 85 and 90 dBA of white noise for equivalent full-day exposures. The damage risk of the two noise levels was determined by comparing the temporary threshold shift (TTS) of 12 subjects exposed to either 85 or 90 dBA of white noise for equivalent half- and full-day exposures. TTS was determined by comparing the pre- and postexposure binaural audiograms of each subject at 1, 2, 3, 4, 6, and 8 kHz. It was concluded that the potential damage risk, that is, hazardous effect, of 90 dBA is greater than 85 dBA of noise for equivalent full-day exposures. The statistical difference between the overall effects of equivalent exposures to 85 dBA as compared to 90 dBA of noise could not be traced to any one frequency. The damage risk of a full-day exposure to 85 dBA is equivalent to that of a half-day exposure to 90 dBA of noise. Within the limits of this study, TTS t was as effective as TTS 2 for estimating the damage risk of noise exposure.

Titania-a 10 20W cm-2 ultraviolet laser

1996 ◽  
Vol 43 (5) ◽  
pp. 1025-1033 ◽  
Author(s):  
E. J. DIVALL
Keyword(s):  
Ultraviolet Laser
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