• Journal of Korean Society of societal Security
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• v.1 no.2
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• pp.87-92
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• 2008

This paper investigates the corrosion property of sprinkler pipe and provides the prevention solution. This study examines the property of stainless pipe widely used as sprinkler pipe and performs theoretical studies on the corrosion procedure. It was found that corrosion of the pipes mainly results from deterioration of pipe and wrong installation. The test result is expected to be useful in designing of the pipe system and minimizing of the corrosion.

• Journal of the Korean Institute of Gas
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• v.6 no.1 s.17
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• pp.10-16
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• 2002

This paper introduces developed prototype intelligent pig which detects corrosion on pipeline by using Magnetic Flux Leakage technology. The 8 inch developed MFL(Magnetic Flux Leakage) pig is composed of 5 yokes which magnetize pipeline wall and 45 Hall sensors which detect MFL signal. The designed MFL modules are analyzed by using magnetic circuit method in order to confirm whether pipeline wall is fully saturated. A variety of artificial defects are manufactured on 8 inch diameter steel pipeline in order to acquire MFL signals. So leakage flux of the axial, radial and circumferential component was acquired as defects. The results of this paper show that design technique for 8 inch MFL pig can be applied to large diameter MFL pig and 0.5mm defect depth can be detected.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.5
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• pp.526-539
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• 2012

A new approach was proposed in this article, named, a non-invasive ultrasonic method to monitor the urinary bladder internal pressure which can resolve the shortcomings of the existing methods. The proposed method makes use of acoustic cavitation. It is based on a physical phenomenon that an extracorporeal high intensity focused ultrasonic pulse generates bubbles inside the urinary bladder and the dynamic properties of the bubbles are related to the urinary bladder internal pressure. The article presents the theoretical foundation for the proposed technique and verifies its feasibility with preliminary experimental data. The suggested ultrasonic urinary bladder internal pressure monitoring method is non-invasive and can be used any time regardless of sex and age, so that it will be of a great benefit to the diagnosis and therapy of urination related diseases.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.1
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• pp.15-21
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• 2004

It is possible to detect flaws in pipelines without interruption using all EMAT transducer because it is a non-contact transducer which can transmit ultrasonic waves into specimens without couplant. And it ran easily generate guided waves desired in each specific problem by altering the design of coil and magnet. In the present work, EMAT systems have been fabricated to generate surface waves, and selectively the plate wave of $A_1\;or\;S_1$ mode. The surface wave of 1.5MHz showed a good signal-to-noise ratio without distortion in its propagation along a pipeline, while the $S_1$ mode of 800kHz and the $A_1$ mode of 940kHz were distorted according to their dispersive properties. The wider the excitation pulse becomes, the better the mode selectivity of the plate waves becomes. A pipe of 256mm inner diameter and 5.5m thickness with 5 flaws was used for comparing the flaw detectability among the modes under consideration.

• Journal of Korean Neurosurgical Society
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• v.30 no.11
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• pp.1340-1344
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• 2001

This is a rare case of cerebral metastasis from malignant fibrous histiocytoma(MFH) of the soft tissue. A 62-year-old man underwent craniotomy for resection of multiple intracerebral masses under the impression of metastatic brain tumor with unknown primary site. Preoperative investigation failed to detect any extracranial lesion. At six months after the operation and whole brain radiotherapy, right shoulder mass was detected to grow and excised. Specimen from the brain and shoulder lesions revealed identical pathological findings of malignant fibrous histiocytoma except existence of glial fibrillary acidic protein(GFAP)-positive cells only in brain lesions. Palliative radiotherapy was performed for subsequently developing metastatic lesions in skeletal system. At twelve months after initial diagnosis recurrent lesion at right shoulder was detected and chemotherapy is given. This case is unique because metastatic brain lesion from MFH is rare and also cerebral metastasis as an initial manifestaion of MFH has not been reported before. Another important finding is that there was expression of GFAP only in brain lesions but not in extracranial primary site lesion. Although the presence of GFAP-positive cells is thought as one of characteristic histological findings of primary intracrainal MFH, our observation supports the hypothesis that GFAP-positive cells in primary intracranial MFH may be nonneoplastic astrocytes secondarily involved by MFH.