• Journal of the Korean Magnetics Society
• /
• v.22 no.2
• /
• pp.42-44
• /
• 2012

We have studied a means to control the composition of nickel-iron thin films. By changing current and voltage applied to a electroplating electrolyte we could manipulate the relative concentration of nickel and iron in the thin films, which caused variations of coercivity, squareness, and saturation magnetic field. As we increase the content of iron in the thin films by using potentiostatic and galvanostatic plating, the grain size was increased and the coercivity was reduced.

• 한국방재학회:학술대회논문집
• /
• 2008.02a
• /
• pp.807-810
• /
• 2008

Permeable reactive barriers containing Zero-valent iron (ZVI) are used to purify ground-water contaminants. One of the representative contaminant is trichloroethylene (TCE). ZVI can act as a reducing agent of TCE. When ZVI is oxidized to Ferric iron, TCE reduced to Ethene, which is non-harmful matter. As a ZVI becomes ferric iron, the reducing effect decreases and iron becomes unavailable. So, constant reduction of TCE requires the regular supply of reducing agent. So, we use Iron-reducing bacteria(IRB) to extend the TCE degrading ability. We perform three experiment DI water, DI water with medium, and DI water with medium and IRB. By the experiment we try to found the dissolve ability.

• Journal of the Society of Disaster Information
• /
• v.9 no.1
• /
• pp.113-122
• /
• 2013

As the patronage of railroad increased, the government tried to introduce several the railroad safety program. The introduction of security inspection system in railroad is also considered with this background. In this paper, we examined the foreign cases in U.S., Spain, and China. Also, we surveyed the railroad users' opinion with the security inspection system and analyzed the results of survey for the sufficient preparation for it. Consequently, we suggested the introduction of high-speed rail station by way of showing an example.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2023.11a
• /
• pp.46-47
• /
• 2023

겨울철에 동아시아는 시베리아 대륙으로부터 부는 북서계절풍의 영향을 크게 받는다. 지속성이 강한 계절풍은 선박의 안전운항과 기상재해에 큰 영향을 미친다. 이 연구에서는 30년간(1992-2021년)의 장기간의 데이터를 이용하여 동아시아에 위치해 있는 우리나라와 일본에서의 겨울철 계절풍의 변화를 분석하였다. 분석한 결과는 다음과 같다. 우리나라 서해안에 위치한 군산에서의 풍속은 시간의 흐름과 함께 약해지는 경향을 보이나, 인천에서는 큰 변화가 보이지 않는다. 우리나라 제주도에 위치한 고산은 다른 두 지역보다 월등히 강한 풍속을 보이나, 이 지역 또한 시간의 흐름과 함께 풍속이 약해지고 있음을 확인하였다. 인천, 군산 및 고산 중에서 풍속이 가장 강한 곳은 고산이고, 그 다음은 인천, 군산의 순이다. 일본의 아키타, 와지마, 하마다의 겨울철 풍속은 세 지역 모두 점진적으로 약해지고 있으나, 2000년에 세 곳 모두 풍속이 급격히 강해진 특징을 보였으며 2005-2007년에는 풍속이 다시 약해졌다. 풍속이 가장 강한 곳은 아키타이며, 그 다음으로는 하마다, 와지마 순이다. 우리나라와 일본을 비교하였을 때, 고산을 제외하고는 일본이 우리나라보다 평균적으로 풍속이 더 강한 양상을 띠고 있어, 서해보다 동해에서 계절풍이 더 강하게 불고 있음을 확인하였다.

• Journal of Internet Computing and Services
• /
• v.21 no.4
• /
• pp.109-116
• /
• 2020

With the advent of high-speed railways, railways are one of the most frequently used means of transportation at home and abroad. In addition, in terms of environment, carbon dioxide emissions are lower and energy efficiency is higher than other transportation. As the interest in railways increases, the issue related to railway safety is one of the important concerns. Among them, visual abnormalities occur when various obstacles such as animals and people suddenly appear in front of the railroad. To prevent these accidents, detecting rail tracks is one of the areas that must basically be detected. Images can be collected through cameras installed on railways, and the method of detecting railway rails has a traditional method and a method using deep learning algorithm. The traditional method is difficult to detect accurately due to the various noise around the rail, and using the deep learning algorithm, it can detect accurately, and it combines the two algorithms to detect the exact rail. The proposed algorithm determines the accuracy of railway rail detection based on the data collected.

• Resources Recycling
• /
• v.23 no.3
• /
• pp.30-36
• /
• 2014

A large amount of waste copper slag containing about 35 ~ 45% iron has been generated and discarded every year from pyrometallurgical processes for producing copper from copper concentrate. Thus, recovery of iron from the waste copper slag is of great interest for comprehensive use of mineral resource and reduction of environment problems. In this study, a physico-chemical separation process for upgrading iron from the waste copper slag discharged as an industrial waste has been developed. The process first crushes the waste copper slag below 1 mm (first crushing step), followed by carbon reduction at $1225^{\circ}C$ for 90 min (carbon reduction step). And then, resulting material is again crushed to $-104{\mu}m$ (second crushing step), followed by wet magnetic separation (wet magnetic separation step). Using the developed process, a magnetic product containing more than 66 wt.% iron was obtained from the magnetic separation under a magnetic field strength of 0.2 T for the waste copper slag treated by the reduction reaction. At the same conditions, the percentage recovery of iron was over 72%. The iron rich magnetic product obtained should be used as a iron resource for making pig iron.

• Journal of the Mineralogical Society of Korea
• /
• v.6 no.2
• /
• pp.105-115
• /
• 1993

$M{\ddot{o}}ssbauer$ and Infrared absorption spectra of the iron-bearing tourmaline minerals show that the ferrous and ferric ions occupy the Y and Z octahedral sites. The Fe ions are almost ferrous, predominantly partitioning into Y site and partly take in Z site. The $Fe^{2+}$ content of the Z sites in brownish black tourmaline minerals are higher than that in blue/green tourmaline minerals. Therefore, 720 nm peak of brownish black samples is broader than that of blue/green samples in optical spectra. All of the blue/green tourmaline minerals used in experiment have only $Fe^{2+}$ ion. The IR spectra of tourmaline depend on the cation environments around OH groups, as also evidenced by their chemical analyses. There appear no difference in IR spectrum between O(1)H and O(3)H binding characters in the heat-treated samples. But the characteristic $3565cm^{-1}$ peak appears in the ferrous hydroxyl bearing silicates, where dehydroxylation temperature for OH coordinated to $Fe^{2+}$ is $700{\sim}800^{\circ}C$.

• Journal of the Korea Concrete Institute
• /
• v.22 no.6
• /
• pp.797-803
• /
• 2010

A dynamic analysis procedure is developed to provide a better estimation of the dynamic responses of pre-stressed concrete (PSC) box girder bridges on the Korea high speed railway. Particularly, a three dimensional numerical model including the structural interaction between high speed vehicles, bridges and railway endures to analyze accurately and evaluate with in-depth parametric studies for dynamic responses of bridge due to the high speed railway vehicles. Three dimensional frame element is used to model the PSC box girder bridges, simply supported span lengths 40 m. The high-speed railway vehicles (K-TGV) including a locomotive are used as 38-degree of freedom system. Three displacements (vertical, lateral, and longitudinal) as well as three rotational components (pitching, rolling, and yawing) are considered in the 38-degree of freedom model. The dynamic analysis by Runge-Kutta method which are able to analyze considering the dynamic impact factors are compared and contrasted. It is proposed as an empirical formula that the impact factors damaged the bridge load-carrying capacities occurs to the bride due to high-speed vehicle.

• 한국해양학회지
• /
• v.28 no.2
• /
• pp.79-85
• /
• 1993

The final biomass yields of 16 marine phytoplankton clones were measured in media with different levels of iron and phosphorus concentrations. The biomass yields of oceanic clones were either only slightly limited or not limited by iron, and those of coastal clones were severely limited by iron in all photogenetic groups other than cyanobacteria. By contrast oceanic cyanobacteria clones as well as coastal clones required higher iron concentrations: minimum concentrations of iron addition for detectable growth of the Synchronous species were estimated to fall between $10^{-9}{\;}and{\;}10^{-8}{\;}M$. Not only the habitat differences (oceanic-coastal trends) but also the photogenetic differences of the oceanic phytoplankton species in the response to the iron enrichments deserve very careful attention before ocean iron fertilization.

• Journal of the Mineralogical Society of Korea
• /
• v.24 no.3
• /
• pp.217-224
• /
• 2011

Removal of dissolved selenium by D. michiganensis, a iron-reducing bacterium, and effects of dissolved metal elements such as iron, sulfate, and copper were investigated. Selenide that was reduced from selenite (2 mM) by D. michiganensis was gradually removed from the aqueous medium. As the reduced selenide was combined with aqueous iron, it was precipitated as a nanoparticulate iron-selenide. Sulfate and copper negatively affected the microbial selenite reduction, and the copper was especially toxic to the bacterium, inhibiting a microbial removal of dissolved selenite. These results show that it should be carefully biotreated for a selenium-contaminated site considering in situ sulfate or copper distribution and concentration. Consequently, the formation of iron-selenide by bacteria will be an important measure for preventing a long-distance migration of selenium in the subsurface environments.