Application of L-SIP to Pressurizer Nozzles

2011 ◽  
Author(s):  
Masaru Watanabe ◽  
Takeshi Ueda ◽  
Koji Okimura ◽  
Kazuhiro Wakabayashi ◽  
Takashi Akaba ◽  
...  
Keyword(s):  
Residual Stress ◽  
Air Cooling ◽  
Water Cooling ◽  
Surface Cooling ◽  
Power Laser ◽  
Cooling Mode ◽  
Steel Pipes ◽  
Inner Surface ◽  
The World ◽  
First Time

It has long been known that the most effective in a countermeasure for stress corrosion cracking in pipe and nozzle welds is by reducing the residual stress in the portion of the weld exposed to the corrosive environment. An irradiated laser stress improvement process (L-SIP) was introduced as a method to improve residual stress inside steel pipes and nozzles. L-SIP has been applied to the pressurizer nozzles in actual plant, Tsuruga unit 2 Japan, for the first time in the world. The nozzles to which this process was applied are the surge nozzle (September 2007), safety nozzles, relief nozzle and spray line nozzle (April 2010). L-SIP can be applied without inner surface cooling because the high power laser beam can generate the sufficient temperature difference without such cooling. Where necessary to achieve optimum temperarure difference, water cooling may also be applied at the inner surface. At Tsuruga unit 2, L-SIP was successfully applied to the spray line nozzle in air-cooling mode, and the surge nozzles, 3 safety nozzles and relief nozzle in water-cooling mode.

Residual Stress Analysis Considering Phase Transformation and Transformation Plasticity for Heat-Treated Large Size Shaft

2016 ◽  
Vol 725 ◽  
pp. 647-652 ◽  
Author(s):  
Yusuke Yanagisawa ◽  
Yasuhiro Kishi ◽  
Katsuhiko Sasaki
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Phase Transformation ◽  
Air Cooling ◽  
Water Cooling ◽  
Stress Distributions ◽  
Transformation Plasticity ◽  
Large Size ◽  
Heat Treated ◽  
Good Agreement

The residual stress distributions of the forgings after both water-cooling and air-cooling were measured experimentally. The residual stress occurring during the heat-treatment was also simulated considering the phase transformation and the transformation plasticity. A comparison of the experiments with the simulations showed a good agreement. These results shows that the transformation plastic strain plays an important role in the heat treatment of large forged shafts.

Application of Outer Surface Irradiated Laser Stress Improvement Process (L-SIP) to Pressurizer as Residual Stress Improvement Method for Alloy 600 PWSCC Mitigation

2008 ◽  
Author(s):  
Takeshi Ueda ◽  
Koji Okimura ◽  
Kazuhiro Wakabayashi ◽  
Takashi Akaba ◽  
Kazuhiko Kamo ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Outer Surface ◽  
Alloy 600 ◽  
Surface Residual Stress ◽  
Steel Pipes ◽  
Inner Surface ◽  
Improvement Process ◽  
Improvement Method ◽  
Work Method

Improvement of residual stress is effective in a countermeasure to deal with the stress corrosion cracks in pipe welds. A irradiated laser stress improvement process (L-SIP) will be introduced as a method to improve residual stress inside steel pipes. This work method is to improve inner surface residual stress from tensile stress to compressive stress by irradiating laser beam around the welds of steel pipe and utilizing the temperature differences between inner and outer surface. Recently this method is applied to PWR pressurizer surge nozzle on TRUGA unit 2.

Effect of Cooling Mode on Properties of a Cast Zinc Alloy

2013 ◽  
Vol 690-693 ◽  
pp. 66-69 ◽  
Author(s):  
Fei Zhang ◽  
Jin Gui Wan
Keyword(s):  
Material Properties ◽  
Cooling Water ◽  
Zinc Alloy ◽  
Air Cooling ◽  
Water Cooling ◽  
Cooling Mode ◽  
Comprehensive Properties ◽  
Alloy Material

In order to explore the best way of zinc alloy cooling, respectively adopting air cooling, water cooling, oil cooling and cooling in the furnace, to study its influence on the zinc alloy material properties. The results show that the oil cooling mode can improve the comprehensive properties of zinc alloy.

scholarly journals Raspberry PI for Kill Mosquitoes by Laser

2021 ◽  
Author(s):  
Ildar Rakhmatulin
Keyword(s):  
Machine Learning ◽  
Neural Networks ◽  
Deep Neural Networks ◽  
Raspberry Pi ◽  
Classification Problems ◽  
Power Laser ◽  
The World ◽  
Aerial Vehicle ◽  
First Time ◽  
Laser Installation

More than 700 thousand human deaths from mosquito bites are observed annually in the world. It is more than 2 times the number of annual murders in the world. In this regard, the invention of new more effective methods of protection against mosquitoes is necessary. In this article for the first time, comprehensive studies of mosquito neutralization using machine vision and a 1 W power laser are considered. Developed laser installation with Raspberry Pi that changing the direction of the laser with a galvanometer. We developed a program for mosquito tracking in real. The possibility of using deep neural networks, Haar cascades, machine learning for mosquito recognition was considered. We considered in detail the classification problems of mosquitoes in images. A recommendation is given for the implementation of this device based on a microcontroller for subsequent use as part of an unmanned aerial vehicle. Any harmful insects in the fields can be used as objects for control.

The Study of Finite Element Simulation for Cooling after Heating Process of Rail

2015 ◽  
Vol 667 ◽  
pp. 224-230
Author(s):  
Feng Qin Yu ◽  
Jun Wang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Element Model ◽  
Heating Process ◽  
Air Cooling ◽  
Water Cooling ◽  
Heating And Cooling ◽  
Suitable Heat Treatment ◽  
Interior Stress ◽  
Dimension Stability

Because of the non-uniformity of the section shape of rail and complexity of its temperature changing, the degree of thermal expansion and contraction of section must be different which leads to the interior stress is produced inevitable in it. The residual stress in rail is elastic stress and its maximum value is elastic limit stress. They affect the dimension stability, mechanical property, deformation and etc. And it is the important factor of rail quality. This paper builds a finite element model of temperature field through the MSC.Marc software during the process of heating and cooling of 55Q rail, which simulates the rail stress field of air cooling and water cooling. Our paper conducts the experiments on the rails of same material and condition and also selects the temperature and stress of appointed nodes to analyze them. The results of experiments and simulations are very identical. Simulating the residual stress of air cooling and water cooling, the result is that residual stress of water cooling is bigger than that of air cooling. This consequence gives the reference for planning the suitable heat treatment and improving the service life.

The Effect of Pipe Thickness on Residual Stresses due to Girth Welds

1982 ◽  
Vol 104 (3) ◽  
pp. 204-209 ◽  
Author(s):  
E. F. Rybicki ◽  
P. A. McGuire ◽  
E. Merrick ◽  
J. Wert
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Residual Stresses ◽  
304 Stainless Steel ◽  
Stress Distributions ◽  
Intergranular Stress Corrosion ◽  
Steel Pipes ◽  
Inner Surface ◽  
Girth Welds ◽  
Intergranular Stress Corrosion Cracking

This paper addresses the question of what effect the pipe thickness has on weld residual stresses in 304 stainless steel piping. Two diameters are considered. These are nominal 4-in. and 10-in. diameters. Four pipe wall thicknesses corresponding to schedules 10, 40, 80, and 160 are examined for each pipe. The focus is on residual stress distributions on the pipe inner surface because this is a primary site for intergranular stress corrosion cracking in 304 stainless steel pipes. The trends in residual stress values are toward more compressive stresses at the pipe inner surface for thicker pipes with the same nominal diameter. Residual axial stresses for the thick 10-in. schedule 160 pipe were found to be compressive while those for the thinner schedule 80 pipe were tensile. X-ray residual stress data for a 6-in-dia schedule 160 pipe fall between the results for the 4-in. and 10-in. schedule 160 pipes and support the findings of the study.

Development of Outer Surface Irradiated Laser Stress Improvement Process (L-SIP)

2006 ◽  
Author(s):  
Noriaki Sugimoto ◽  
Hironori Onitsuka ◽  
Koji Okimura ◽  
Takahiro Ohta ◽  
Kazuhiko Kamo
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Laser Beam ◽  
Stress Corrosion ◽  
Outer Surface ◽  
Surface Residual Stress ◽  
Steel Pipes ◽  
Inner Surface ◽  
Improvement Process ◽  
Work Method

Improvement of residual stress is effective in a countermeasure to deal with the stress corrosion cracks in pipe welds. A irradiated laser stress improvement process (L-SIP) will be introduced as a method to improve residual stress inside steel pipes. This work method is to improve inner surface residual stress from tensile stress to compressive stress by irradiating laser beam around the welds of steel pipe and utilizing the temperature differences between inner and outer surface.

Improvement of Residual Stresses of Circumferential Joint of Pipe by Heat-Sink Welding

1986 ◽  
Vol 108 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Y. Ueda ◽  
K. Nakacho ◽  
T. Shimizu
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Heat Sink ◽  
Welding Residual Stress ◽  
Water Cooling ◽  
Intergranular Stress Corrosion ◽  
Steel Pipes ◽  
Nuclear Plants ◽  
Intergranular Stress Corrosion Cracking ◽  
Theoretical Analyses

Intergranular stress corrosion cracking may occur in some specific conditions on the inner surface of the welded joints of stainless steel pipes which are furnished in nuclear plants. One of the remedies for this cracking is to convert welding residual stress on this surface into compression. In this research, in order to improve welding residual stress, the authors investigated the effectiveness of the heat-sink welding (water cooling) by conducting theoretical analyses and experiments on SUS 304 pipes of different sizes in comparison with the conventional welding. The mechanisms of production of residual stresses by both methods are clarified and conditions for effective application of the heat-sink welding such as limitation of heat input, procedure of welding are indicated.

scholarly journals Raspberry PI for Kill Mosquitoes by Laser

2021 ◽  
Author(s):  
Ildar Rakhmatulin
Keyword(s):  
Machine Learning ◽  
Neural Networks ◽  
Deep Neural Networks ◽  
Raspberry Pi ◽  
Classification Problems ◽  
Power Laser ◽  
The World ◽  
Aerial Vehicle ◽  
First Time ◽  
Laser Installation

More than 700 thousand human deaths from mosquito bites are observed annually in the world. It is more than 2 times the number of annual murders in the world. In this regard, the invention of new more effective methods of protection against mosquitoes is necessary. In this article for the first time, comprehensive studies of mosquito neutralization using machine vision and a 1 W power laser are considered. Developed laser installation with Raspberry Pi that changing the direction of the laser with a galvanometer. We developed a program for mosquito tracking in real. The possibility of using deep neural networks, Haar cascades, machine learning for mosquito recognition was considered. We considered in detail the classification problems of mosquitoes in images. A recommendation is given for the implementation of this device based on a microcontroller for subsequent use as part of an unmanned aerial vehicle. Any harmful insects in the fields can be used as objects for control.

SEROPREVALENCE OF HIV AND HBsAg AMONGST BLOOD DONORS IN A TERTIARY CARE HOSPITAL, CHHATTISGARH.

2019 ◽  
Vol 3 (8) ◽  
Author(s):  
Anusha P ◽  
Bankar Nandkishor J ◽  
Karan Jain ◽  
Ramdas Brahmane ◽  
Dhrubha Hari Chandi
Keyword(s):  
Hepatitis B ◽  
Blood Donors ◽  
Hepatitis B Surface Antigen ◽  
Tertiary Care ◽  
Laboratory Diagnosis ◽  
Blood Bank ◽  
Care Hospital ◽  
Medical College ◽  
The World ◽  
First Time

INTRODUCTION: India being the second highly populated nation in the world. HIV/AIDS has acquired pandemic proportion in the world. Estimate by WHO for current infection rate in Asia. India has the third largest HIV epidemic in the world. HIV prevalence in the age group 15-49 yrs was an estimate of 0.2%. India has been classified as an intermediate in the Hepatitis B Virus (HBV) endemic (HBsAg carriage 2-7%) zone with the second largest global pool of chronic HBV infections. Safety assessment of the blood supply, the quality of screening measures and the risk of transfusion transmitted infectious diseases (TTIs) in any country can be estimated by scrutinizing the files of blood donors. After the introduction of the blood banks and improved storage facilities, it became more extensively used. Blood is one of the major sources of TTIs like hepatitis B, hepatitis C, HIV, syphilis, and many other blood borne diseases. Disclosure of these threats brought a dramatic change in attitude of physicians and patients about blood transfusion. The objective of this study is to determine the seroprevalence of transfusion transmitted infections amidst voluntary blood donors at a rural tertiary healthcare teaching hospital in Chhattisgarh. MATERIAL AND METHODS: This retrospective study was carried out in Chandulal Chandrakar Memorial Medical College, Kachandur, Durg. Blood donors were volunteers, or and commercial donors who donated the blood and paid by patients, their families, or friends to replace blood used or expected to be used for patients from the blood bank of the hospital. After proper donation of blood routine screening of blood was carried out according to standard protocol. Laboratory diagnosis of HIV 1 and HIV 2 was carried out by ELISA test. Hepatitis B surface antigen was screened by using ELISA. RESULTS: A total of 1915 consecutive blood donors’ sera were screened at Chandulal Chandrakar Memorial Medical College, blood bank during study period. Of these 1914 were male and 1 female. The mean age of patients was found to be 29.34 years with standard deviation (SD) of 11.65 Years. Among all blood donors in present study, 759(39.63%) were first time donors and 1156(60.37%) were repeated donors. 1 patient was HIV positive in first donation group while 3 (75%) were positive in repeat donation group. 7 (38.9%) were HBsAg positive in in first donation group while 11(61.1%) were positive in repeat donation group. Two patients in first donation group had dual infection of HIV and HBsAg. CONCLUSION: Seropositivity was high in repeated donors as compared to first time donors. The incidence of HIV is observed to be 0.2% and that of HBsAg is 0.94%. Strict selection of blood donors should be done to avoid transfusion-transmissible infections during the window period.

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