• Journal of Welding and Joining
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• 제7권1호
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• pp.28-35
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• 1989

The fatigue crack growth behavior in GTA butt welded joints of Al-Alloy 5052-H38 was examined using Single Edge Notched(SEN) specimens. It is well known that welding residual stress has marked influence on fatigue crack growth rate in welded structure. In the general area of fatigue crack growth in the presence of residual stress, it is noted that the correction of stress intensity factor (K) to account for residual stress is important for the determination of both stress intensity factor range(.DELTA.K) and stress ratio(R) during a loading cycle. The crack growth rate(da/dN) in welded joints were correlated with the effective stress intensity factor range(.DELTA.Keff) which was estimated by superposition of the respective stress intensity factors for the residual stress field and for the applied stress. However, redistribution of residual stress occurs during crack growth and its effect is not negligible. In this study, fatigue crack growth characteristics of the welded joints were examined by using superposition of redistributed residual stress and discussed in comparison with the results of the initial welding residual stress superposition.

• 대한조선학회지
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• 제21권1호
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• pp.43-47
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• 1984

The purpose of this paper is to investigate theoretically the effect of residual stress due to welding in stress intensity factor of a plate containing the Model I Crack in different crack size and location, and on fatigue crack growth rate. The initiation of crack is found to be possible only in the region of tensile residual stress. The most dangerous crack has the values of d/b and a/b equal to about 0.6 and 1.0, respectively, where d/b is the ratio of distance from the crack to welding bead and the width of tensile residual stress region and a/b is the ratio of crack length and tensile residual stress region. The crack perpendicular to and on the line of welding bead and with a/b equal to about 0.6 has maximum stress intensity factor. The theoretical fatigue crack growth rate under residual stress and applied stress, which is obtained from Forman's Law by stress superposition, is relatively in good agreement with Glinka's[8] experimental value. The fatigue crack growth is shown to be retarded due to residual stress distribution.

• 한국환경보건학회지
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• 제19권2호
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• pp.1-9
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• 1993

In public water supply systems, Alum and/or PAC being used as a coagulant. It is well known that their use increased frequently the concentration of residual aluminum in filtered water upon operating conditions. This study was conducted to find the optimum conditions that both the concentration of residual aluminum and turbidity are minimized by changing such factors as pH, temperature, alum dosage, mixing rate, alkalinity and hardness. The results can be summarized as follows: The pH values for the minimum concentration of residual aluminum and turbidity as a given experimental condition were found at pH 6 and pH 7 respectively, the apparent clarity was best at pH 8. The floc settling rate was the greatest at pH 6.5, but the turbidity was high at the same condition. The more alum dosage, the higher the concentration of residual aluminum. However the alum dosage less than 15 mg/l tend to decrease in turbidity. Restabilization and enmeshment occurred near 15 mg/l and 20 mg/l of alum dose respectively. With the increase of mixing rate (rapid and slow), the concentration of residual aluminum and turbidity are increased and the same trend was found in increment of mixing time. At low water temperature, the concentration of residual aluminum was decreased, but turbidity was increased. It was confirmed that alkalinity had an effect on the coagulation efficiency, but hardness did not.

• Journal of Welding and Joining
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• 제5권1호
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• pp.73-80
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• 1987

During PWHT, it is well known that residual stress in weld HAZ is one of the reasons for PWHT embitterment. In case of static loading, it was experimentally found that fracture toughness of weld HAZ was dependant upon PWHT conditions. However, the effects of PWHT on fatigue behavior are not clearly verified. Therefore, in this paper, the effects of heating rate PWHT conditions and residual stress simulated in weld HAZ of Cr-Mo steel on fatigue crack propagation behavior were evaluated by fatigue Testing and SEM observation. The obtained results are summarized as follows; 1. Applied stress($10 Kgf/mm^2$) in weld HAZ during PWHT tneded to decrease fatigue strength and to increase fatigue crack growth rate. 2. Applied stress and slow heating rate of 60.deg. C/hr during PWHT contributed to precipitin of impurity elements as well as carbide, which promoted the fatigue crack growth. 3. Fatigue crack growth rate decreased at the heating rate of 220.deg. C/hr in contrast with 600.deg. C/hr and 60.deg. C/hr.

• Asian Pacific Journal of Cancer Prevention
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• 제13권9호
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• pp.4835-4837
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• 2012

Objectives: To evaluate residual disease in uterine cervical cancer patients treated with teletherapy using combined high dose rate Cobalt-60 brachytherapy. Materials and Methods: A retrospective study of uterine cervical cancer patients, FIGO stages IB-IVB (International Federation of Gynecologists and Obstetricians recommendations), treated by radiotherapy alone between April 1986 and December 1988 was conducted and the outcomes analysed. The patients were treated using teletherapy 50 Gy/25 fractions, five fractions per week to the whole pelvis together with HDR Cobalt -60 afterloading brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions. Results: The study covered 141 patients with uterine cervical cancer. The mean age was 50.0 years with a range of 30-78 years. The mean tumor size was 4.1 cm in diameter (range 1-8 cm). Mean follow - up time was 2.94 years (range 1 month-6.92 years). The overall incidence of residual locoregional disease was 3.5%. Residual disease, according to stage IIB, IIIB and IVA was present in 2.78%, 3.37% and 50.0%. It was noted that there was no evidence of residual disease in stage IB and IIA cases. Conclusion: Combined teletherapy along with high dose rate Cobalt -60 brachytherapy of 850 cGy/fraction, weekly to point A for 2 fractions resulted in overall 3.5% residual disease and a 96.5% complete response. The proposed recommendation for improving outcome is initiation of measurements for early detection of disease.

• IEIE Transactions on Smart Processing and Computing
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• 제5권5호
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• pp.323-326
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• 2016

High Efficiency Video Coding (HEVC) adopts intra transform skip mode, in which a residual block is directly quantized in the pixel domain without transforming the block into the frequency domain. Intra transform skip mode provides a significant coding gain for screen content. However, when intra-prediction errors are not transformed, the errors are often correlated along the intra-prediction direction. This paper introduces a residual differential pulse code modulation (DPCM) method for the intra-predicted and transform-skipped blocks to remove redundancy. The proposed method performs pixel-by-pixel residual prediction along the intra-prediction direction to reduce the dynamic range of intra-prediction errors. Experimental results show that the transform skip mode's Bjøntegaard delta rate (BD-rate) is improved by 12.8% for vertically intra-predicted blocks. Overall, the proposed method shows an average 1.2% reduction in BD-rate, relative to HEVC, with negligible computational complexity.

• 대한치과보철학회지
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• 제52권2호
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• pp.136-142
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• 2014

최근 많이 이용되고 있는 지르코니아-도재 수복물은 그 적용범위가 점차로 증가하고 있다. 임상연구결과에서 지르코니아 코어는 매우 높은 성공율을 보이고 있으나 코어 위에 축성되는 전장도재는 기존에 이용되어온 금속-도재 수복물에 비해 높은 파절빈도를 나타내고 있다. 이러한 파절의 원인으로 여러가지 요소가 거론되고 있으나 아직 명확하게 설명하고 있지는 못하다. 최근 전장도재 축성 후 냉각과정에서 잔존하는 잔류응력이 전장도재의 파절에 영향을 미칠 수 있다는 연구결과가 속속 발표되고 있다. 본 고찰에서는 잔류응력이 무엇이며 도재 축성 후 냉각과정에서 어떤 기전을 통해 전장도재 내에 잔류응력이 발생하는지, 또한 기존의 금속-도재 수복물에서 발생하는 잔류응력과는 어떤 차이가 있는지 문헌고찰을 통해 살펴보고자 한다.

• 한국물환경학회지
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• 제20권3호
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• pp.206-214
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• 2004

Residual wall thicknesses, corrosion rates, and residual life of thirty four samples of cast iron pipes(CIPs) and ductile cast iron pipes(DCIPs) collected from water mains of B city were studied to estimate their remaining service life or optimum time of rehabilitation. The internal maximum corrosion depths of samples measured using a dial gauge after shot blasting were twice higher than the external in most cases. Therefore corrosion of water pipes was much more affected by internal water quality than soil. Residual wall thicknesses of DCIPs were higher than those of CIPs. That reason was thought to be that DCIPs have been protected from internal corrosion by lining cement mortar. Residual life calculated by maximum corrosion rate was ranged up to 44 years with 12.40 years average. Since most CIPs were much deteriorated, rehabilitation plan should be established soon in B city. Residual life of DCIP was 33.52 years average. When cement mortar lining is used up by neutralization of DCIPs. DCIP also should be rehabilitated.

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1617-1628
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• 2017

In the passive residual heat removal system of a molten salt reactor, one of the residual heat removal methods is to use the thimble-type heat transfer elements of the drain salt tank to remove the residual heat of fuel salts. An experimental loop is designed and built with a single heat transfer element to analyze the heat transfer and flow characteristics. In this research, the influence of the size of a three-layer thimble-type heat transfer element on the heat transfer rate is analyzed. Two methods are used to obtain the heat transfer rate, and a difference of results between methods is approximately 5%. The gas gap width between the thimble and the bayonet has a large effect on the heat transfer rate. As the gas gap width increases from 1.0 mm to 11.0 mm, the heat transfer rate decreases from 5.2 kW to 1.6 kW. In addition, a natural circulation startup process is described in this paper. Finally, flashing natural circulation instability has been observed in this thimble-type heat transfer element.

• 한국식품영양과학회지
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• 제24권2호
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• pp.214-218
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• 1995

Elimination of residual captan during the storage and cooking process was investigated. The concentration of residual captan after sticking and drying fo captan on spinach was 2.938ppm. During storage of 5, 10, 15 and 20 days at 15$^{\circ}C$, the amount of residual captan decreased to 73.18, 80.80, 89.99 and 98.40% of the initial amount, respectively. When spinach was stored at 3$^{\circ}C$, the concentration of residual captan decreased to 58.20, 61.37, 72.84 and 76.31% and the storage was carried out at -17$^{\circ}C$, residual captan amount decreased to 7.18, 22.67, 34.58 and 40.91% of the initial amout, respectively according to the storage period. In the case of the residual captan of seasoned spinach, the storage of 2, 24 and 48 hours at 15$^{\circ}C$, the amout of residual captan decreased to 0.772(39.69%), 0.661(77.50%) and 0.063ppm(97.86%) of the initial amount, respectively. When spinach was stored at 3$^{\circ}C$, the amount of residual captan decreased to 2.344 (20.22%), 1.021(65.25%) and 0.329ppm(88.80%) and the storage was carried out at -17$^{\circ}C$, residual captan amount decreased to 2.428(17.36%), 1.520(48.26%) and 0.726ppm(75.29%) of the initial amount, respectively according to the storage period. In the case of the residual captan of spinach cooked with edible oil for 2, 4 and 6 minutes and then cooking oil was discarded, each decreasing rate of the captan sticked to thespinach was 96.29, 97.86 and 99.18%, respectively. The rate of removed the captan sticked to the spinach with oil was 73.32, 86.32 and 87.13%, respectively. From these results, the storage in room temperature and the addition of seasoning to the spinach could lead to decrease in the concentration of the residual captan, furthemore the cooking could inhance decreasing of residual captan.