• Journal of Welding and Joining
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• 제31권4호
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• pp.28-33
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• 2013

The effects of laser welding beam quality is very large. However, not an analysing case was found for the difference on the plasma emission signal during laser welding according to the beam quality. Therefore, in this study, we compared and evaluated penetration and signal change according to the beam quality at the a similar wavelength band by using a fiber laser and Nd:YAG laser. In addition, we took high speed videography in order to make sure that FFT analysis reflects the actual motion period of keyhole and found the period of video analysis and FFT mostly matched. As a result, it is expected to secure higher reliability than evaluating signal intensity when appling FFT to monitoring.

• 한국축산식품학회지
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• 제30권4호
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• pp.603-608
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• 2010

This study investigated the effects of electron beam irradiation on pathogens, quality, and functional properties of shell eggs during storage. A 1st grade 1-d-old egg was subjected to electron beam irradiation at 0, 1, 2, and 3 kGy, after which the number of total aerobic bacteria, reduction of inoculated Escherichia coli and Salmonella Typhimurium, egg quality, and functional properties were measured. Electron beam irradiation at 2 kGy reduced the number of E. coli and S. Typhimurium cells to a level below the detection limit (<$10^2$ CFU/g) after 7 and 14 d of storage. Egg freshness as measured by albumen height and the number of Haugh units was significantly reduced by 1-kGy irradiation. The viscosity of irradiated egg white was also significantly decreased by increased irradiation, whereas its foaming ability was increased. Electron beam irradiation also increased lipid oxidation in egg yolks. These results suggest that electron beam irradiation reduces the freshness of shell eggs while increasing the oxidation of egg yolk and improving important functional properties such as foaming capacity. Electron beam irradiation can also be applied to the egg breaking process since the irradiation reduces the viscosity of egg white, which can allow egg whites and yolks to be separated with greater efficiency.

• Nuclear Engineering and Technology
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• 제38권4호
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• pp.319-326
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• 2006

A brief review is presented on the ion beam application in science and technology. ion beams are used very effectively in various fields of science and technology, on the basis of advance in accelerator technology and experimental techniques for ion beam utilization. Recent progress in this field is reviewed in terms of the direct ion beam utilization like ion beam analysis, and the utilization of neutrons as secondary particles.

• 대한방사선기술학회지:방사선기술과학
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• 제11권1호
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• pp.3-16
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• 1988

Author has made an experiment on absolute speeds of 18 screenfilm combinations that have been on sale in Korea, with various beam qualities. At this time, the beam qualities were 60kVp with the ANSI extremity phantom, 80kVp with the ANSI chest phantom and 85kVp with 20 mm aluminium filter under scatter free condition. The obtained results were as follows; 1. When three independent measurements were performed, the percent standard deviations of mAs quantities of 1.0 + fog were decreased by the hardening of the beam quality, and the decreasing tendency was somewhat great in the blue systems. 2. Generally, the increasing tendency of absolute speeds was distinct by the hardening of the beam quality in the green systems. Conclusively, the green systems were more strongly dependent upon the beam quality rather than the blue systems. Therefore, the relative speed of green systems to blue systems were great under the same condition. 3. Differences in the green systems were kept almost constant even though the beam qualities were changed. 4. They were shown the mutual relationship of absolute speed and relative speed rather than independent.

• 대한안전경영과학회지
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• 제17권1호
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• pp.119-124
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• 2015

According as radiation therapy technique develops, standardization of radiation therapy has been complicated by the plan QA(Quality Assurance). However, plan QA tools are two type, OADT (opposite accumulation dose tool) and 3DADT (3 dimensional accumulation dose tool). OADT is not applied to evaluation of beam path. Therefore tolerance error of beam path will establish measurement value at OADT. Plan is six beam path, five irradiation field at each beam path. And beam path error is 0 degree, 0.2 degree, 0.4 degree, 0.6 degree, 0.6 degree, 0.8 degree. Plan QA accomplishes at OADT, 3DADT. The more path error increases, the more plan QA error increases. Tolerance error of OADT path is 0.357 using tolerance error of conventional plan QA. Henceforth plan QA using OADT will include beam path error. In addition, It will increase reliability through precise and various plan technique.

• Asian-Australasian Journal of Animal Sciences
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• 제23권8호
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• pp.1112-1117
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• 2010

This study was conducted to evaluate and compare the quality changes of commercial sliced and pizza cheeses processed by gamma and electron beam irradiation. The $L^*$-value of sliced and pizza cheeses decreased and the $a^*$-value decreased only in pizza cheese by both irradiation sources. There was no change in pH. There was no difference in 2-thiobarbituric acid reactive substances (TBARS) value between non-irradiated and irradiated samples at a dose of 3 kGy or less (p<0.05). However, both irradiation sources resulted in increased TBARS value in sliced and pizza cheeses at 5 kGy. Sensory evaluation revealed that irradiation influenced odor, taste and overall acceptability of both cheeses and may cause the limitation of consumers' acceptance for irradiated cheese products. Results indicate that both gamma and electron beam irradiations with less than 3 kGy may not influence significantly the physicochemical quality of sliced and pizza cheeses. However, to meet a market requirement, a method to overcome the sensory deterioration of cheeses should be developed and applied.

• Journal of Welding and Joining
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• 제13권3호
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• pp.96-105
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• 1995

An advantage offered by brazing over fusion welding is that strong joints may be produced at relatively low heat input. To minimize the thermal effects and maintain the desired dimension of assemblies. the CO$_{2}$ laser beam can be applied to the brazed joint of pin and plate as a micro heat source. This paper presents a analysis model of the laser brazing process considering the laser beam mode and heat flow in brazed parts by using the finite element method. The simulation results were compared with the experimental results obtained from the infrared temperature sensing system. Based on these results, the proper process parameters were investigated to get a good joining quality. The influence of the beam mode change was examined with respect to the temperature distribution and joint quality.

• 한국방사선학회논문지
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• 제15권1호
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• pp.79-83
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• 2021

방사선 치료 영역에서 전자선은 표재성 병변 치료에 자주 쓰인다. 전자선은 빔 경로에 것들과 상호 작용하여 선량측정에 영향을 끼치기에 정확한 측정이 요구된다. 하지만 전자선 정도관리에 관한 연구는 이루어지고 있지 않는 실정이다. 이에 본 연구에서는 전자선 정도관리를 위한 기초연구로 PbO 기반의 선량계를 제작하였다. 그리고 6, 9, 12 MeV 에너지에 따른 재현성, 선형성을 분석하여 계측정확성과 정밀성을 평가하였다. 재현성 측정결과 6, 9, 12 MeV에서 각각 1.024%, 1.019%, 0.890%의 RSD 값으로 나타났다. 그리고 선형선 측정결과에서는 6, 9, 12 MeV에서 모두 0.9999 R2로 나타났다. 두 평가 모두 우수한 결과로 PbO 선량계의 계측정확성과 정밀성이 매우 우수한 것으로 나타났다.

• 전기학회논문지
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• 제63권9호
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• pp.1281-1285
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• 2014

Recently, as the wide spread of smart phone, pico projector which is used at the smart phone is appeared as a portable display device. In this paper, among several pico projectors, laser beam scanner module is dealt with in which laser is used as light source, and mems-mirror is used as optical panel. In this device, screen image quality is a special issue, and blur effect is a typical adverse effect to the quality of this device. So the enhancement of this blur effect has an important factor of the quality of the device. The definition of the blur and the main source of the blur are studied and the simulation results and way of improvement are also suggested.

• 방사선산업학회지
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• 제8권1호
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• pp.1-5
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• 2014

This study investigated the reduction of microbial population and sensory properties in red pepper powders irradiated by gamma ray, electron beam, and X-ray. Populations of total aerobic bacteria and yeast & molds in red pepper powders were decreased by irradiation treatment in a dose-dependent manner. Gamma ray, electron beam, and X-ray at doses above 8 kGy caused 100% inhibition on growth of aerobic bacteria in red pepper powders. Inhibitory activity of X-ray on sterilization of red pepper powders was significantly equal to or higher compared to gamma ray and electron beam. Color and off flavor in red pepper powders were no significant difference among the control and samples irradiated with gamma ray, electron beam, and X-ray. As a result, the gamma ray, electron beam, and X-ray irradiation can be used to sterilize the microbial growth in red pepper powders without quality loss.