• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.260-265
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• 2004

The materials of ship screw propeller are commonly the manganese bronze. The seawater corrosion and cavitation of the screw propeller reduce tire propulsive performance of ship. In screw manufactory, tire corrosion rust of tire screw propeller is removed by a hand grinding. The grinding work makes the dust of the heavy metals from the manganese bronze. The dust makes indoor working environment poor. A friendly-environmental and automatic corrosion removing apparatus was developed for the improvement of screw processing and working environment. The corrosion rust of a screw propeller was remarkably removed by using apparatus. And the screw surface roughness was improved by a blasting effect of the apparatus performance test. Anode polarization curves on jour processing conditions, that is to say, grinding, blasting, wire-brushing, fine sand papering, were confirmed by a potentiostat. Especially, two kinds of medias, alumina and emery, were used in the blasting processing. Then, investigated tire cavitation erosion of specimen. This result proved that tire blasting work has considerably improved the corrosion resistance of a screw propeller.

• 한국의사학회지
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• 제29권1호
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• pp.103-116
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• 2016

The location of BL61 has commonly known as directly under the BL60 (Gollyun) which is at the lateral side of the heel. SP2 is located at the front of the big toe joint and SP3 is located at the rear of the big toe joint. These locations are the same with the standard acupuncture points of the WHO/WPRO. However, according to Chimgeumdongin (鍼金銅人), BL61 is located at the center of calcaneal tuberosity, which is close to the bottom of the heel, not at the side. SP2 is located at the rear of the big toe joint, not at the front. SP3 is located at the rear of sesamoid bone, not at the rear of the big toe joint. These can be also found in Douningyou (銅人形) c-544 with the same locations. Moreover, these locations are precisely equal in reference to the acupuncture classics such as < Zhenjiujiayijing : 鍼灸甲乙經 >, < Buzhutongrenjing : 補註銅人經 >, whereas the descriptions of the standard acupuncture points of the WHO/WPRO and the locations of acupuncture points in Zhenjiutongren (鍼灸銅人), Zhinjiuxueweitongren (鍼灸穴位銅人) are totally different from the acupuncture classics. Therefore, there needs to be further examinations on WHO/WPRO Standard Acupuncture Point with various acupuncture bronze men.

• 한국전기전자재료학회논문지
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• 제27권8호
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• pp.510-515
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• 2014

Thin films of cubic $Na_{0.6}WO_3$, which is one of the sodium tungsten bronze, were fabricated by rf sputtering for the electrode applications in integrated sensors and actuators. A single-phase cubic $Na_{0.6}WO_3$ sputtering target of power type was prepared by conventional solid-state reaction. Thin films were deposited from the powder target, and the as-deposited films were amorphous, thus they annealed by tube furnace or RTP for crystallization. Thin films having cubic phase $Na_xWO_3$ were fabricated by the optimization of sputtering and post-annealing conditions, but single-phase cubic $Na_{0.6}WO_3$ thin films were not obtained. Although the films were not in single phase, they had good electrical conduction properties showing electrical resistivities of $10-4{\Omega}{\cdot}cm$ order.

• 보존과학연구
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• 통권16호
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• pp.41-58
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• 1995

Several comparisons of treatment methods for stabilizing corroded Chinese coins at Shin-an marine sites were investigated. In aqueous solution, the seexamination were performed to show whether chloride ions are gradually removed, patination changes are acceptable and archaeological details are identified. The six desalting methods showed that the orders of removal of chloride ions were ranked electrolysis (electolyte : 0.1M sodium sesqui.)> 5% sodium dithionite(1M NaOH)> 5%sodium dithionite(0.1M sesqui.)> 5% citric acid> 0.1M sodium sesquicarbonate>deionized water. As the examinations of moisture absorption to the relative humidity has compared for bronze disease, all of desalted coins for the R.H 53% and R.H 75%except to R.H 95% are showed serious bronze disease.

• Tribology and Lubricants
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• 제11권4호
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• pp.45-52
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• 1995

The wear behavior of alumina short fiber reinforced tin-bronze matrix composites was studied at the room temperature and an elevated temperature. The effect of the composition of specimens and the variation of wear conditions on the wear properties was examined by a pin-on-disc type wear testing machine. The wear mechanism according to the compositon of specimens at various wear conditions was discussed by the observation of the microstructure and the analysis of the composition on the worn surfaces. A thicker oxide layer on worn surfaces led to a lower wear loss because of the lubricating effect of oxide layers between pin and disc. As the testing temperature was raised to 350$^{\circ}$C, the fiber reinforced composites exibited markedly increased wear resistance even at a higher applied load since the reinforcement of composites with alumina fibers was not affected to a large extent by raising temperature. The results obtained by AES and EDS analysis indicated that the oxide layer of the worn surfaces formed at 350$^{\circ}$C was proved as Fe-oxide. This was explained by the faster formation of Fe-oxide than Cu-oxide at 350$^{\circ}$C.

• 한국표면공학회지
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• 제25권3호
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• pp.107-116
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• 1992

The optimum thickness of Pd-Ni plated layers used as an electrical contact film was investigated by evaluating mechanical, thermal and environmental characteristics. The variations of morphologies and chemical compositions were studied by using SEM, EDS and ESCA. As a result of wear test, the wear resistance behavior of the gold plated layers was not changed with the sliding velocity changes. The palladium-nickel plated layer showed better wear resistance than the gold plated layer at low sliding velocity, but it showed poor wear resistance at high sliding velocity. Under the thermal condition of $400^{\circ}C$ in air, the gold thickness of $2\mu\textrm{m}$ without underplate on phosphorous bronze formed copper oxide on the surface layer by rapid diffusion of copper whereas the gold thickness of $0.8\mu\textrm{m}$ deposited on nickel and palladium-nickel underplate was stable at $400^{\circ}C$. Under the sulfur dioxide environments, the gold thickness of $0.3\mu\textrm{m}$ deposited on the nickel thickness of$ 3\mu\textrm{m}$ and the palladium-nickel thickness of $2\mu\textrm{m}$ underplate was more corrosion-resistant than the gold thickness of $2\mu\textrm{m}$ without underplate on phosphorous bronze. Under the nitric acid vapor environment, corrosion resistance of the gold film was superior to an equivalent thickness of the palladium-nickel film.

• 한국표면공학회지
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• 제45권4호
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• pp.143-150
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• 2012

Laser cleaning have been found to be a useful cleaning tool to remove contaminants without inducing damage to the substrate and making secondary pollutant. In this study, the effect of Nd:YAG laser cleaning system, emitting at 1064 nm and 532 nm, on acrylic resin applied onto copper coupons and pieces of bronze was investigated. The samples after laser cleaning tests were examined using microscopy, FT-IR, SEM-EDS. As a result, the acrylic resin could be removed from most of the samples at low laser energy density. Laser wavelength 532 nm was more effective than 1064 nm because of using lower laser energy density, which could reduce heat damage to substrates. Although the acrylic resin was easily removed, it revealed melted surfaces and removed bronze patina which must remain. The problems should be solved by future studies using different laser system or laser wavelengths.

• 대한설비공학회지:설비저널
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• 제5권3호
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• pp.169-177
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• 1976

The importance of surface conditions of nucleate boiling is well recognized and it has been known that the heat transfer to boiling liquid is closely related to the bubble population density. The bubble population density should depend on various factors such as heat flux, surface roughness, surface contamination, properties of liquid, etc. In this paper the effect of surface conditions on heat transfer in nucleate boiling is treated. The experiments were carried out with distilled water boiler, on the horizontal heating surfaces, sintered with various bronze particle, under atmospheric pressure. In addition, experimental investigation for the polished bronze surface was performed. By studing a coefficient Xb defined by eq. (9), which represents the bubble foaming ability of heating surface, generalized fomula on the heat transfer in the nucleate toiling were expressed. The coefficient $X_b$, determined empirically, is not constant and indicates a major influence of the sintered metal surfaces on the $\Delta$, necessary to sustain nucleate boiling at any given heat flux. In this study, the main results are obtained as follows; (1) At low temperature difference, the coefficient $X_b$ of sintered metal surface was found to he higher than the polished surface throughout the full range of experiments. (2) The optimum sintered structure showing the maximum coefficient $X_b$ has been confirmed to exist and it is encountered when particle diameter is $256{\mu}$.

• Anatomy and Cell Biology
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• 제56권3호
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• pp.404-408
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• 2023

In arctic zone of West Siberia, native people's bodies were sometimes mummified inside the medieval graves. In 2013 to 2017, we conducted the excavations of medieval graves at Zeleny Yar cemetery in Yamalo-Nenets Autonomous Okrug. Among the burials, current report deals with the mummy grave #79. During the investigation, bronze plate and strips, woven or fur clothing, leather strap, beads, bronze bracelets, and iron knife etc. were collected. Anatomical and radiological research showed that the mummy was found intact with hair, skin, and skeletons, but the preservation status of soft tissue differed greatly depending on the area. The brain and eyes were well preserved, but the chest and abdominal organs almost disappeared. The arms were preserved to some extent, but only the bones remained in the legs. The West Siberian mummy could be a great resource for anthropologists to reveal the biological aspects of arctic indigenous people.

• 헤리티지:역사와 과학
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• 제43권3호
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• pp.48-101
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• 2010

이 논문은 한반도 남부와 일본열도 서반부를 중심으로 한 지역에 있어서 금속기의 생산과 유통이 활발했던 시기의 실연대를 $^{14}C$연대측정을 통해 추정한 글이다. 이 시기의 일상용기였던 점토대토기의 실연대를 구축하여, 토기와 금속기의 고고학적 출토양상을 통해 세형동검문화의 성립과 철기의 출현연대를 밝히고자 하였다. 연구사를 통해 점토대토기 기원전 300년 상한설이 학계의 대세임을 알 수 있는데, 이는 현재에도 계속해서 지지되고 있다. 이것은 세형동검문화의 성립연대와 초기철기시대의 개시연대와도 연동되고 있는 것이다. 한편에서는 세형동검문화와 원형점토대토기문화의 성립을 동일시하는 견해를 지지하지 않는 연구자도 있으며, 목탄의 $^{14}C$연대를 통해 점토대토기의 출현시기를 올려 보는 분위기가 형성되고 있었다. 연구사에서 드러난 문제점을 지적하면서, 필자가 직접 조사를 통해 채취 처리한 시료를 중심으로 $^{14}C$연대측정을 실시, 그 결과를 바탕으로 점토대토기의 실연대를 구축하였는데, 그 시료는 약 100점에 달한다. 원형점토대토기는 기원전 6세기에 출현했을 가능성이 높고, 삼각형점토대토기는 기원전 300년 전후에 출현한 것으로 파악하였다. 철기는 원형점토대토기의 가장 늦은 단계에 출현하기 때문에 그 출현연대를 기원전 4세기라고 볼 수 있는데, 이는 실제로 철기와 원형점토대토기가 공반된 유적의 $^{14}C$연대와도 정합적이었다. 이를 통해 기원전 4세기 초~중엽일 가능성을 제시하였고, 초기 철기가 출토된 유적보다 확실히 이전 단계에 해당되는 초창기의 세형동검문화는 기원전 5세기 후반으로 파악하였다. 이렇게 파악된 실연대는 야요이토기와의 병행관계 및 $^{14}C$연대와도 정합적이며, 고고학적 사실에 근거한 것이기 때문에 가능성 높은 연대라고 할 수 있다. $^{14}C$연대를 통한 한일 공통의 편년이 처음으로 구축된 것이다. 새로이 구축된 점토대토기의 실연대에 의하면, 현재 학계의 일반적인 시대구분과는 맞지 않기 때문에, 연대의 조정을 통해 새로운 수정안을 제시하였다. 철기의 출현시기(기원전 4세기 초~중엽)부터 초기 철기시대로 하여, 청동기시대는 원형점토대토기 단계의 상당 부분과 세형동검문화를 포함하는 것으로 보았다. 이를 청동기시대 후기로 설정하여, 송국리식을 중기로 하는 안을 제시하였다.