• 제목/요약/키워드: Ion Irradiation

검색결과 453건 처리시간 0.025초

Ni-Zn 합금도금에 미치는 초음파의 영향(I) (Effects of Ultrasonic Waves on Electrodeposition on Nickel-Zinc Alloys(I))

  • 양학희
    • 한국표면공학회지
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    • 제20권1호
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    • pp.4-14
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    • 1987
  • The nickel-zinc alloy depositions have been studied in nickel chloride added chloride baths, to find out the effects of ultrasonic irradiation for the electrodeposition processes. The compositions of deposited alloys, the current efficiencies and the metallographic appearances in various conditions of Electrodeposition were investigated, in the range of ultrasonic irradiation of 50,500 and 1,000 Kc/s respectively. The results obtained are as follows; 1. Generally the nickel deposition process is more preferably activated than that of zinc by the ultrasonic irradiation. 2. The radios of nickel to zinc in the deposit are higher according to increase of nickel ion concentration and bath temperatures in irradiated baths. 3. The current efficiencies are also higher in the irradiated baths, so that the depolarization effect is noticeable. 4. The brightness and leveling effect of the deposits are appreciably better in the irradiated baths than in non-irradiated in 0.3M and 0.6M of nickel chloride and zinc chloride solutions and the current density of 3A/$dm^2$. 5. The mechanism of alloy deposition has been tentatively suggested in the case of ultrasonic irradiation.

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Multiscale Simulation of Yield Strength in Reduced-Activation Ferritic/Martensitic Steel

  • Wang, Chenchong;Zhang, Chi;Yang, Zhigang;Zhao, Jijun
    • Nuclear Engineering and Technology
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    • 제49권3호
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    • pp.569-575
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    • 2017
  • One of the important requirements for the application of reduced-activation ferritic/martensitic (RAFM) steel is to retain proper mechanical properties under irradiation and high-temperature conditions. To simulate the yield strength and stress-strain curve of steels during high-temperature and irradiation conditions, a multiscale simulation method consisting of both microstructure and strengthening simulations was established. The simulation results of microstructure parameters were added to a superposition strengthening model, which consisted of constitutive models of different strengthening methods. Based on the simulation results, the strength contribution for different strengthening methods at both room temperature and high-temperature conditions was analyzed. The simulation results of the yield strength in irradiation and high-temperature conditions were mainly consistent with the experimental results. The optimal application field of this multiscale model was 9Cr series (7-9 wt.%Cr) RAFM steels in a condition characterized by 0.1-5 dpa (or 0 dpa) and a temperature range of $25-500^{\circ}C$.

New Monte-Carlo based simulation program suitable for low-energy ions irradiation in pure materials

  • Ghadeer H. Al-Malkawi;Al-Montaser Bellah A. Al-Ajlony;Khaled F. Al-Shboul;Ahmed Hassanein
    • Nuclear Engineering and Technology
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    • 제55권4호
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    • pp.1287-1299
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    • 2023
  • A new Monte-Carlo-based computer program (RDS-BASIC) is developed to simulate the transport of energetic ions in pure matter. This computer program is utilizing an algorithm that uses detailed numerical solutions for the classical scattering integral for evaluating the outcomes of the binary collision processes. This approach is adopted by several prominent similar simulation programs and is known to provide results with higher accuracy compared to other approaches that use approximations to shorten the simulation time. Furthermore, RDS-BASIC simulation program contains special methods to reduce the displacement energy threshold of surface atoms. This implementation is found essential for accurate simulation results for sputtering yield in the case of very low energy ions irradiation (near sputtering energy threshold) and also successfully solve the problem of simultaneously obtaining an acceptable number of atomic displacements per incident ions. Results of our simulation for several irradiation systems are presented and compared with their respective TRIM (SRIM-2013) and the state-of-the-art SDTrimSP simulation results. Our sputtering simulation results were also compared with available experimental data. The simulation execution time for these different simulation programs has also been compared.

Micro-Spot Atmospheric Pressure Plasma Production for the Biomedical Applications

  • Hirata, T.;Tsutsui, C.;Yokoi, Y.;Sakatani, Y.;Mori, A.;Horii, A.;Yamamoto, T.;Taguchi, A.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.44-45
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    • 2010
  • We are currently conducting studies on culturing and biocompatibility assessment of various cells such as neural stem cells and induced pluripotent stem cells(IPS cells) on carbon nanotube (CNT), on nerve regeneration electrodes, and on silicon wafers with a focus on developing nerve integrated CNT based bio devices for interfacing with living organisms, in order to develop brain-machine interfaces (BMI). In addition, we are carried out the chemical modification of carbon nanotube (mainly SWCNTs)-based bio-nanosensors by the plasma ion irradiation (plasma activation) method, and provide a characteristic evaluation of a bio-nanosensor using bovine serum albumin (BSA)/anti-BSA binding and oligonucleotide hybridization. On the other hand, the researches in the case of "novel plasma" have been widely conducted in the fields of chemistry, solid physics, and nanomaterial science. From the above-mentioned background, we are conducting basic experiments on direct irradiation of body tissues and cells using a micro-spot atmospheric pressure plasma source. The device is a coaxial structure having a tungsten wire installed inside a glass capillary, and a grounded ring electrode wrapped on the outside. The conditions of plasma generation are as follows: applied voltage: 5-9 kV, frequency: 1-3 kHz, helium (He) gas flow: 1-1.5 L/min, and plasma irradiation time: 1-300 sec. The experiment was conducted by preparing a culture medium containing mouse fibroblasts (NIH3T3) on a culture dish. A culture dish irradiated with plasma was introduced into a $CO_2$-incubator. The small animals used in the experiment involving plasma irradiation into living tissue were rat, rabbit, and pick and are deeply anesthetized with the gas anesthesia. According to the dependency of cell numbers against the plasma irradiation time, when only He gas was flowed, the growth of cells was inhibited as the floatation of cells caused by gas agitation inside the culture was promoted. On the other hand, there was no floatation of cells and healthy growth was observed when plasma was irradiated. Furthermore, in an experiment testing the effects of plasma irradiation on rats that were artificially given burn wounds, no evidence of electric shock injuries was found in the irradiated areas. In fact, the observed evidence of healing and improvements of the burn wounds suggested the presence of healing effects due to the growth factors in the tissues. Therefore, it appears that the interaction due to ion/radicalcollisions causes a substantial effect on the proliferation of growth factors such as epidermal growth factor (EGF), nerve growth factor (NGF), and transforming growth factor (TGF) that are present in the cells.

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감마선 조사된 배추 및 브로콜리의 전처리방법에 따른 전자스핀공명분석 특성 (Characterization and Identification of Gamma-Irradiated Kimchi Cabbage and Broccoli by Electron Spin Resonance Spectroscopy using Different Sample Pre-treatments)

  • 곽지영;안재준;;김귀란;권중호
    • 한국식품과학회지
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    • 제44권5호
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    • pp.532-539
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    • 2012
  • 섬유소 식품의 조사처리 여부 확인에서 전자스핀공명분석법의 개선을 위한 기초자료를 마련하고자, 감마선 조사된 브로콜리와 배추의 전처리 건조방법(FD, OD, ALD, 및 WAD)에 따른 cellulose radical을 분석 비교하였다. 브로콜리 시료에서는 single central signal($g_0$=2.0007)이 나타났으며, 배추 시료에서는 single central signal 외에 $Mn^{2+}$ ion에 의한 sextet signal이 추가로 발견되었다. 조사처리한 채소류에서는 singlet signal을 중심으로 좌우 두 개의 side peak가 나타났으며, 각 side peak의 거리는 5.8-6.1 mT로 조사처리 유래의 cellulose radical임을 확인할 수 있었다. 채소류의 부위별로 ESR spectra를 비교한 결과, 배추는 뿌리와 줄기, 브로콜리는 잎, 줄기 모두 조사처리 여부를 판별하는데 있어 적합하였다. 건조 방법별로는 FD와 OD 처리 시 ESR 강도는 더 높았으나, $Mn^{2+}$ ion과 함께 나타나 명확한 signal을 얻기 어려웠다. 반면, ALD와 WAD 방법의 경우 $Mn^{2+}$ ion이 제거되고, signal ratio도 적합하게 나타나 조사 처리된 채소류의 ESR 판별시, ALD와 WAD 방법이 가장 적합할 것으로 판단되었다.