기온에 따른 소금 수용액의 제설성능 분석

마경훈,오한진 한국도로학회 2024 한국도로학회논문집 Vol.26 No.2

PURPOSES : Snow-removal performance is performed in this study to assess the feasibility of replacing calcium-chloride solution with sodium chloride solution at the minimum temperature of -5 ℃ during snowfall. METHODS : The atmospheric temperature distribution in Seoul was analyzed. The manufacturing, storage, and indoor melting performance of calcium-chloride and sodium-chloride solutions were evaluated, and on-site snow-removal performance was evaluated based on the solution type. RESULTS : According to the results of the melting performance test at -5°C, the melting capacity of the sodium chloride solution was expressed at a level exceeding 90% of that of the calcium chloride solution, indicating a similar melting performance between the two solutions. Additionally, based on the snow removal performance test using aqueous solutions, the snow removal performance of the sodium chloride solution was found to be approximately 96% compared to that of the calcium chloride solution, indicating minimal differences in snow removal performance due to changes in the type of solution. CONCLUSIONS : Similar snow-removal performance was achieved when the sodium chloride solution was used instead of calciumchloride aqueous solution at temperatures exceeding -5 ℃.

모르타르 내 염화물 고정화와 중성화의 상호영향에 관한 연구

소승영(So Seung-Young) 대한건축학회 2003 大韓建築學會論文集 : 構造系 Vol.19 No.7

Chloride ions introduced into the concrete through m ix ingredients such as unw ashed chloride-contaminated coastal sands used as fine aggregates and enter concrete from outside sources during the service life of structures. If Chloride ions exist in the vicinity of the steel w ill show pitting corrosion even though the pH of the environment is higher than 11.0. Carbonation of cover concrete is considered one of the most common culprits in the corrosion of steel in concrete. It breaks down the passive film and allows the steel to corrode actively at a high rate. The main objective of this study is to investigate the interrelationship between chloride binding and speed of carbonation by conducting an accelerated carbonation test on mortar which chlorides were m ixed. It was found that chloride-bearing mortar were accelerated carbonation and the Friedel's salt were broken down in carbonation. Also CO₂ has affected Ca(OH)₂ and ettringite. The amount of chlorides in non-carbonation zone is twice as much as adding chlorides because chlorides in carbonation is to move toward the non-carbonation zone.

Modelling of chloride diffusion in saturated concrete

Wen-Hu Tsao,Nai-Ming Huang,Ming-Te Liang 사단법인 한국계산역학회 2015 Computers and Concrete, An International Journal Vol.15 No.1

The process of chloride ingress in saturated concrete was presented by a previous study that used a mathematical model for the same as that concrete. This model is to be studied chloride ion diffusion which is considered as a chemical phenomenon and is to be represented the chloride diffusion process to be a nonlinear partial differential equation (PDE). In this paper, this nonlinear PDE is solved by the Kirchhoff transformation to render into a linear PDE. This linear PDE associated with initial and boundary conditions is also solved by the Laplace transformation to obtain an analytical solution. To verify the serviceability and reliability of this proposed method, the practical application should be supplied. The input parameters were cited from the previous study. The free chloride concentration profiles obtained by the analytical solution of mathematical model for saturated concretes after 24 and 120 hrs of exposure were compared with the previous study. The predicted results obtained from proposed method have a tendency with experimental results obtained by the previous study and trend toward numerical results approximated by finite difference technique.

LIBS를 활용한 수용액과 모르타르 내 염화물량 분석

류화성 ( Ryu Hwa-sung ),박원준 ( Park Won-jun ) 한국건축시공학회 2021 한국건축시공학회지 Vol.21 No.3

본 연구에서는 Lab. 스케일 LIBS 장치를 제작하여 모르타르 내 염화물 분석에서의 LIBS 적용성과 재현성 검토를 수행하였다. 염화물 함량을 조절한 모르타르를 대상으로 기존의 분석방법(XRF, 전위차 적정법)과 LIBS 분석을 동시에 진행하였다. LIBS 분석 결과, 염소이온은 837.59nm 파장에서 검출되었고, 다양한 농도 구간에서의 정밀도를 향상시키기 위하여 전기장 강화를 통한 약 50배의 LIBS 신호증폭을 구현하였다. 수용액 기반의 재현성을 검증을 통하여 LIBS 신호 강도와 Cl농도 사이의 높은 상관관계를 확인할수 있었으며, 콘크리트 염해 내구성 진단에 LIBS적용 가능성을 확인하였다. LIBS has been attracting attention as an analytical method capable of real-time measurement without sample preparation. In this study, a Lab. scale LIBS device was fabricated to examine the applicability and reproducibility of LIBS in the analysis of chloride contents in mortar. The existing analysis method and LIBS analysis were performed simultaneously on the mortar test specimen with the chloride content adjusted. Compared to the chloride content condition of the mortar, the XRF and Potentiometric Titration results also showed a similar trend. As a result of LIBS analysis, chlorine ions were detected at a wavelength of 837.59 nm according to the chloride content condition. In order to improve the precision in various concentration ranges, the LIBS signal amplification of about 50 times through the electric field enhancement was implemented. Through the verification of the aqueous solution-based reproducibility, a high correlation between the LIBS signal strength and the Cl concentration was confirmed, and the possibility of applying LIBS to the durability diagnosis of concrete damage by chloride was confirmed.

Effects of 20% Aluminum Chloride in Axillary Hyperhidrosis not Accompanying Osmidrosis

Kim, Seok-Won,Lee, Seung-Myung The Korean Neurosurgical Society 2005 Journal of Korean neurosurgical society Vol.37 No.4

Objective: Surgical treatment of focal axillary hyperhidrosis is often unsatisfactory because of compensatory hyperhidrosis. The purpose of this study is to evalute the effect of decreased sweating production using 20% aluminum chloride on axillary hyperhidrosis. Methods: From February to December, 2002, 10 patients (mean age 25.2 male 2, female 8) with clinical diagnosis of axillary hyperhidrosis were treated by 20% aluminum chloride solution. Until the desired degree of symptom relief was obtained, they were educated to apply every day and thereafter, the agent would be applied as often as is necessary. We analyzed patient's satisfaction and application time at onset of desired dryness, application interval to maintain the relief of symptom and side effects. Results: Aluminum chloride solution was effective in treatment of axillary hyperhidrosis showing excellent result in 60% of patients and good in 40%. Application time at onset of desired dryness ranged from 1 to 6 days(mean 3 days). Application interval to maintain the relief of symptom ranged from 5 to 45 days(mean 12 days). There were no significant complications but just mild irritation and miliaria in seven patients. Conclusion: 20% aluminum chloride solution is the simple, safe and less expensive method for initial treatment for axillary hyperhidrosis not accompanying osmidrosis.

Chemical Model for Solvent Extraction Equilibrium of Mn(II) by Cyanex 272 from Chloride Solutions

( Nagaphani Kumar Batchu ),( Bo Eun Kim ),( Man Seung Lee ) 대한금속재료학회(구 대한금속학회) 2014 대한금속·재료학회지 Vol.52 No.6

Solvent extraction equilibrium of manganese(II) using Cyanex 272 dissolved in kerosene was studied from chloride solutions. Distribution ratio data was collected in order to estimate the extraction equilibrium constant. A slope analysis method was used to verify the solvent extraction reaction. The equilibrium constant for the solvent extraction reaction was estimated by taking into account the complex formation reactions between Mn(II) and chloride ion and mass balance equations. The activity coefficients of species in the aqueous phase were estimated by applying the Bromley equation. A comparison was made between the calculated distribution ratios of Mn(II) and the experimentally measured values. Finally, a chemical model was successfully applied for the estimation of the equilibrium constant. (Received October 1, 2013)

Diluents Role in Extraction and Possible Separation of Light Rare Earth Elements from Chloride Solutions by using Cyanex® 272 used as an Extractant

Rajesh Kumar Jyothi,김혜림,김준수,정경우,이진영 대한금속·재료학회 2018 대한금속·재료학회지 Vol.56 No.10

The present paper deals with liquid-liquid extraction studies and the possible separation of light rare earths (LREs) from chloride solutions. Aromatic diluents such as benzene, toluene and xylene were tested for LREs extraction and possible separation from chloride solutions. Bis(2,4,4-triethylpentyl)phosphinic acid (trade name Cyanex® 272) was used as an extractant and dissolved in the diluents. Various experimental parameters such as time effect, influence of pH, extractant concentration variation and maximum loading capacity of the target LREs to Cyanex® 272 were examined. Finally, the separation potential of each of the other LREs was calculated, and a suitable diluent system was proposed. The highest separation factors were found using the present systems.

시멘트 페이스트 내의 염화물 고정화에 미치는 플라이 애쉬의 영향

소승영,소양섭 한국콘크리트학회 1995 콘크리트학회지 Vol.7 No.6

철근의 부식은 철근콘크리트 구조물의 열화에 가장 영향이 큰 요소이며, 염화물 이온에 의한 염해는 철근부식을 일으키는 가장 일반적인 원인 중의 하나이다. 본 연구는 콘크리트의 성능개선과 내구성 향상을 위해 사용량이 증가하고 있는 플라이 애쉬의 시멘트 경화체 내에서의 $Cl^-$고정화에 미치는 영향을 검토하기 위해 밀봉용기 내에서 양생시킨 재령28일 공시체의 세공용액을 추출하여 세공용액 중의 $Cl^-$, $OH^-$농도 측정과 세공용액 추출용과 같은 배합 공시체의 증발수량 측정으로 세공용액량 및 시멘트 페이스트내에서의 $Cl^-$ 고정화량을 산정한 것이다. 연구결과 플라이 애쉬 치환이 시멘트 경화체내 세공용액의 $Cl^-$농도와 프리델씨염 생성량 및 고정화량 증가에 미치는 영향은 거의 없고, 철근부식에 관계하는 $Cl^-$/$OH^-$는 증가하는 것으로 나타났다. Corrosion of steel reinforcment is the most significant factor of deterioration in reinforced concrete structures. Chloride ion is considered one of the most common culprits in the corrosion of steel in concrete. It breaks down the passive film and allows the steel to corrode actively at a high rate. The main objective of this study is to determine the critical chloride ion concentrations in the pore solutions and chloride binding effect of cement pastes made with and without fly ash. Cement pastes with water-binder ratio of 0.5, allowed to hydrate in sealed containers for 28 days and to express pore solution. The expressed pore fluids were analyzed for chloride and hydroxyl ion concentrations. Evaporable water on paralled specimens was determined a.s the loss of weight per 100g of unhydreded cement when the specimens were heated to constant weight at 105'C. It was found that the replaced cement with fly ash has negligible influnce on the chloride binding and chloride binding capacity and rises the $Cl^-$ /$OH^-$ ratio in pore solution.

철-니켈 합금 에칭구액 용매추출 공정 용액으로부터 고순도 탄산니켈 제조에 관한 연구

채병만,황성옥,이석환,김득현,이상우,김대원,최희락,Chae, Byung-man,Hwang, Sung-ok,Lee, Seok-Hwan,Kim, Deuk-Hyeon,Lee, Sang-Woo,Kim, Dae-Weon,Choi, Hee-Lack 한국결정성장학회 2017 韓國結晶成長學會誌 Vol.27 No.6

여러 가지 금속을 에칭하기 위하여 사용된 $FeCl_3$ 폐용액은 유가금속인 니켈을 함유하고 있다. 본 연구에서는 염화철을 재생하고 남은 니켈 함유 에칭폐액으로부터 니켈을 고순도의 탄산니켈 결정분말로 회수하고자 하였다. 5 % NaOH 수용액을 이용하여 pH 4의 조건에서 1차적으로 철 성분의 불순물을 약 97 % 제거하고 추가적으로 남은 불순물을 제거하기 위하여 용매추출제 D2EHPA(Di-(2-ethylhexyl) phosphoric acid)를 사용하여 불순물로서 존재하는 금속이온들을 약 99% 제거하였다. 그 후 불순물이 제거된 염화니켈 용액에 탄산나트륨과의 반응을 통하여 99.9 % 이상의 순도를 가진 탄산니켈분말을 얻을 수 있었다. The $FeCl_3$ waste solution used to etch various metals contains valuable metal such as nickel. In this study, we recovered as high purity nickel carbonate crystalline powders from nickel-containing etching waste solution after regeneration of iron chloride. Firstly we eliminated about of the iron impurities under the condition of pH 4 using 5 % NaOH aqueous solution and then removed the remaining impurities such as Ca, Mn and Zn etc. by using solvent extractant D2EHPA (Di-(2-ethylhexyl) phosphoric acid). Thereafter, nickel carbonate powder having a purity of 99.9 % or more was obtained through reaction with sodium carbonate in a nickel chloride solution.

염화물 수용액에서 자작나무 수액을 이용한 철강의 부식 억제

박태준 ( Tae-jun Park ),김기애 ( Ki Ae Kim ),이지이 ( Ji Yi Lee ),장희진 ( Heejin Jang ) 한국부식방식학회(구 한국부식학회) 2018 Corrosion Science and Technology Vol.17 No.5

The effects of birch sap, a possible natural corrosion inhibitor, on the corrosion behavior of steel in chloride solution were investigated. The corrosion rate was significantly reduced by the addition of 1~5 mL of birch sap to 500 mL of 3wt% NaCl or 3wt% CaCl₂ solution. A remarkable increase in the pitting potential in NaCl solution was observed by the addition of birch sap although it was almost constant in CaCl2 solution. The corrosion rate of steel in both NaCl and CaCl₂ birch sap solution without addition of water was higher compared to that of aqueous solution without birch sap as the pH of the birch sap was 4.0. The presence of organic compounds like, fructose, galactose, glucose, and palmitic acid in the birch sap are thought to be adsorbed effectively on the metal surface, which provided corrosion protection. However, the inorganic elements including Na, Ca, K, Mg, Mn, S, etc. present in the birch sap exhibited no role in corrosion inhibition.