• Journal of Korea Multimedia Society
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• v.19 no.2
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• pp.105-111
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• 2016

In order to inspect the quality of spot welding, inefficient destructive test and NDT (non destructive testing) utilizing expensive foreign ultrasonic inspection are being conducted in the automobile production lines, but NDT will be difficult to be used in the domestic automobile production due to complexity of the waveform analysis and lack of mobility. In this paper, NDT system inspecting the quality of spot welding based on mobile network is proposed to complement drawbacks of the conventional inefficient destructive testing and NDT inspecting the quality of spot welding. Regardless of daily condition of NDT tester, the proposed NDT system can determine the quality of spot welding automatically and transmit the information of NDT quality to smart devices of field workers in real-time so that convenience of NDT and productivity of automobile production will be improved. Several specimens with a variety of welding quality was produced to evaluate the performance of the proposed mobile ultrasonic NDT system and the conventional foreign equipment, through this experiments, the proposed mobile ultrasonic NDT system indicate the superior properties compared to the conventional equipment in terms of convenience, productivity, and economic.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.1041-1046
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• 2022

Nucleoside deoxyribosyltransferase (NDT) is an enzyme that replaces the purine or pyrimidine base of 2'-deoxyribonucleoside. This enzyme is generally used in the nucleotide salvage pathway in vivo and synthesizes many nucleoside analogs in vitro for various biotechnological purposes. Since NDT is known to exhibit relatively low reactivity toward nucleoside analogs such as 2'-fluoro-2'-deoxynucleoside, it is necessary to develop an enhanced NDT mutant enzyme suitable for nucleoside analogs. In this study, molecular evolution strategy via error-prone PCR was performed with ndt gene derived from Lactobacillus leichmannii as a template to obtain an engineered NDT with higher substrate specificity to 2FDU (2'-fluoro-2'-deoxyuridine). A mutant library of 214 ndt genes with different sequences was obtained and performed for the conversion of 2FDU to 2FDA (2'-fluoro-2'-deoxyadenosine). The E. coli containing a mutant NDT, named NDT^L59Q, showed 1.7-fold (at 40℃) and 4.4-fold (at 50℃) higher 2FDU-to-2FDA conversions compared to the NDT^WT, respectively. Subsequently, both NDT^WT and NDT^L59Q enzymes were over-expressed and purified using a His-tag system in E. coli. Characterization and enzyme kinetics revealed that the NDT^L59Q mutant enzyme containing a single point mutation of leucine to glutamine at the 59^th position exhibited superior thermal stability with enhanced substrate specificity to 2FDU.

• Journal of Welding and Joining
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• v.35 no.2
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• pp.63-70
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• 2017

As the Non Destructive Test (NDT) for the welded structure, PT(Penetration Test). MT(Magnetic Test), RT (Radioisotope Test) and UT(Ultrasonic Test) methods are widely used in practice. These NDT methods have been developed toward high efficiency, low cost, real time, and high precise new NDT. For example, RT methods are developed to CT(Computed Tomography)and DR(Digital Radiography), and UT metheds are developed into Phased array, Guide wave, TOFD method. Moreover, the Infrared thermography and Laser ultrasonic technique are newly developed for applying in high temperature objects as the non-contact NDT methods. In this review paper the new high efficiency NDT methods for the welded structure are introduced and the trend of NDT rules applying in welded structure are described.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.188-192
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• 2015

Gemological and spectroscopic properties of HPHT synthetic diamonds from New Diamond Technology (NDT) company in St. Petersburg (Russia) were examined. Their color (colorless, near-colorless with some boron and Fancy blue with high boron content) and clarity ($VVS-SI_1$) grades were comparable to those of top natural diamonds. NDT synthetic diamonds fluoresced and phosphoresced blue or orange under SWUV light. Photoluminescence spectra revealed H3 center with very small intensity and NV centers. The intensity of H3 in NDT synthetic diamond has very weak in comparison with natural one. Using a combination of gemological and spectroscopic tests, gem-quality synthetic diamonds from NDT can be distinguished from natural diamonds of similar quality.

• Journal of the Korean Society for Nondestructive Testing
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• v.12 no.4
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• pp.32-39
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• 1993

Past, present and future of nondestructive testing and evaluation(NDT&E) activities in Korea are reviewed. The current status and future direction in NDT&E research and development are presented. The newly revised edition of Korean NDT personnel qualification system is described. Other activities such as NDT&E training programs, NDT field services, and professional societies and international cooperation are also summarized. Founded in 1980, the Korean Society for Nondestructive Testing is now the center of domestic activities in NDT&E as well as the gateway to the international cooperation.

• The Journal of Pediatrics of Korean Medicine
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• v.35 no.1
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• pp.139-147
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• 2021

Objectives The purpose of this study is to investigate differences in brain activities when Neurodevelopmental treatment (NDT) is used alone compare to NDT is combined with intradermal acupuncture (IDA) treatment, using functional infrared spectroscopy (fNIRS) Methods Three children less than 7 year-old with cerebral palsy were participated. On their first visit, only NDT was used. After a week, they were treated with both NDT and IDA. During the treatment, fNIRS was used to measure any changes in their brain activities. Results In first patient with NDT, oxyhemoglobin level was increased during Standing exercise and Gait training compared to resting state. When the patient was treated with NDT and IDA, oxyhemoglobin level was decreased during Standing exercise and Gait training compared to resting state, and the result was significant (p<0.05). In second patient, oxyhemoglobin level was decreased in Gait training compared to resting state when NDT was used, but the level was increased when NDT and IDA were used in Gait training compared to resting state (p<0.05). In third patient, the difference in oxyhemoglobin levels between Gait training and resting state was significant (p<0.05). Conclusions Treatment involving both NDT and IDA has more potential to improve brain activities compared to that of NDT alone, and no adverse effect was reported. In order to confirm the finding, larger scale randomized controlled trials are needed.

• Journal of the Korean Professional Engineers Association
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• v.33 no.6
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• pp.23-29
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• 2000

The nondestructive tests(NDT) are widely applied at various industrial job sites to detect defects and flaws early and thus to diagnose the quality and integrity of components, structures and systems. This paper discusses the R&MD history of various nondestructive testing techniques, their applications and many technical as well as safety issues identified, particularly in the performance of radiography. Also discussed are the principles of inspection methods and NDT qualifications that should be applied at the industrial job sites. As a result, this paper provides suggestions for improvement in Government programs to promote th NDT industry, for more systematic operation through a direct with the owner, and also for improvement in working conditions for NDT workers.

• Nuclear industry
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• no.4 s.4
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• pp.17-28
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• 1978

• Journal of the Korean Society for Nondestructive Testing
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• v.2 no.2
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• pp.36-51
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• 1983

Nondestructive testing activities in Korea are summarized. Present activities and the future direction in NDT programs are presented. Korean NDT personnel qualification system is also presented. Training program, NDT services, and activities of professional societies also explained.

• Journal of the Korean Society for Nondestructive Testing
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• v.1 no.1
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• pp.45-59
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• 1981

Nondestructive testing activities in Korea are summarized. Past programs and the future direction in NDT research and development are presented. Korean NDT personnel qualification system is compared with the US system. Training program, NDT services, and professional societies are also explained.