Study on Cold Expansion Process of High Pressure Components

2013 ◽  
Vol 312 ◽  
pp. 469-474
Author(s):  
Shi Jin Zhang ◽  
Yan Li Wang ◽  
Feng Ling Yang
Keyword(s):  
High Pressure ◽  
Pressure Field ◽  
Strengthening Mechanism ◽  
Fatigue Properties ◽  
Expansion Process ◽  
Cold Expansion ◽  
Short Period ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Very High

In high pressure water jet field, most components worked under very high fluctuated pressure. The high and fluctuated pressure would fail those components quickly, which leads to very short period of fatigue life for high pressure components. Cold expansion process could improve components fatigue properties greatly. This has been known for a while. By applying this process in high pressure field, much longer service time is expected. This paper investigated the cold expansion process experimentally. Based on micro-structure investigation, the strengthening mechanism has been explored.

Improved Optoelectronic Characteristics of Nanocrystalline Porous Silicon by High-Pressure Water Vapor Annealing

2004 ◽  
Vol 832 ◽  
Author(s):  
Bernard Gelloz ◽  
Akira Kojima ◽  
Nobuyoshi Koshida
Keyword(s):  
High Pressure ◽  
Porous Silicon ◽  
Surface Passivation ◽  
High Surface ◽  
Peak Wavelength ◽  
Si Nanocrystals ◽  
Vapor Annealing ◽  
Pressure Water ◽  
Annealing Pressure ◽  
Very High

ABSTRACTA high-pressure H2O vapor annealing technique has been applied to nanocrystalline porous silicon (PS). The effects on the photoluminescence (PL) are reported here for PS samples of different initial porosities, in different conditions of the annealing pressure. A drastic enhancement of the PL intensity has been achieved, while both the emission band and the peak wavelength remain almost unchanged. The best results have been obtained with an initial PS porosity of about 68 %. The resulting layers consist of Si nanocrystals embedded into an SiO2tissue. The high external quantum efficiency obtained in treated PS (23%) may be attributed mainly to a very high surface passivation by high quality oxide and an enhancement in the localization of photoexcited carriers.

Development of Very High Pressure Water-jet for Cleaning Naval Boiler Tubes

1976 ◽  
Vol 13 (03) ◽  
pp. 272-278
Author(s):  
T. P. Tursi ◽  
R. J. DeLecce
Keyword(s):  
High Pressure ◽  
Surface Finishing ◽  
Potential Applications ◽  
Pressure Water ◽  
Cleaning Procedures ◽  
High Pressure Water Jet ◽  
Safety Considerations ◽  
Removal Equipment ◽  
Very High ◽  
Deposit Removal

Mechanical brushing has been the standard method for removing soft deposits from the watersides of steam generating tubes in U. S. Naval boilers. Problems with that method such as limited deposit removal, equipment breakage and jamming of brushes in tubes led to a program to develop more rapid, effective, and trouble-free methods of soft deposit removal. The use of very high pressure water evolved out of that program. This paper describes the research and development conducted to improve water-jetting and apply it to naval boiler tube cleaning. It describes the development of optimum pressures, flow rates, nozzle and flexible lance configurations, control methods, degree of deposit removal, cleaning procedures, safety considerations and many other aspects, including the Navy-wide adoption of this method. Also mentioned are other potential applications of water-jetting for cleaning, removal of tight deposits and coatings, and for machining and surface finishing operations.

Uses of Very High Pressure Water-jet Cleaning in Marine Maintenance

1976 ◽  
Vol 13 (03) ◽  
pp. 263-271
Author(s):  
Sidney A. Taylor ◽  
R. S. Judson
Keyword(s):  
High Pressure ◽  
Cost Savings ◽  
Water Jet ◽  
Potential Cost ◽  
Cleaning Method ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Very High ◽  
Basic Equipment

High pressure water-jet cleaning, using pressure up to 10,000 psi, has proven to be a very versatile, efficient, and less costly method of performing many types of marine maintenance. This paper covers three aspects of this cleaning method. A review is made of the basic equipment required and the commercial configurations that are available. Frequently used applications are briefly discussed along with their efficiency and potential cost savings. Finally, the relevant antipollution standards and their effect on cleaning techniques are evaluated.

scholarly journals A Clinical Study to Assess the Efficacy of Agastimodakain the Management of Abhyantara Arshaw.s.r. to 1st and 2nd Degree Internal Haemorrhoids.

2021 ◽  
Vol 04 (11) ◽  
pp. 01-12
Author(s):  
Monika Sharma
Keyword(s):  
High Pressure ◽  
Sedentary Lifestyle ◽  
Treatment Protocol ◽  
Cost Effective ◽  
Venous Plexus ◽  
Erect Posture ◽  
Chief Complaints ◽  
Present Case Study ◽  
Very High

ARSHA, one of the Ashta-Mahagadasappears at the Gudaregion, which is a kind of Sadhyapranahar Marma. In Humans, the erect posture results in very high pressure on the valve less rectal venous plexus which makes them prone to this disease. It is a problem related to old age, sedentary lifestyle & dietary factors.Vega Vidharan, ati ushna-tikshana and mamsaaharaleads to Vitiation of Apana vayu, that primarily causes Agni Mandata & Mala avashtamba in the affected individulas. The fourfold treatment protocol given in Ayurvedic context gives more emphasis to start with a Conservative Management -BHESHAJAYA KARMAin Arsha.The present case study includes 45 patients diagnosed with Abhyantra Arshawith chief complaints as Per Rectal Bleeding (Raktasrava), Constipation (Mala bandhta) and Pile Mass (Arsha ankura). An attempt is made to prepare an easily accessible,standard & cost effective palliative mode in terms of AGASTIMODAKA to treat the cases of 1st& 2ndDegree Internal Haemorrhoid. All the ingredients of Agastimodakaare Katu, Tikta, Kashaya Rasatmaka, Madhura Vipaki. It presents as a good Aam Pachaka, shool prashamaka, mala shodhakaand rakta stambhaka. Owing to its Deepana-Pachana property, it regulates Agniwhich improves the digestion and relieves constipation by lowering the pressure on anal varices. A significant relief was observed in all the three study included parameters.Bheshajya Karmahas no fear of complications like infection, gangrene and bleeding in comparison to the Allopathic Surgical procedures.

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