CFRP materials are one of the excellent lightweight materials of the next generation. Also, the CFRP materials are attracting materials form the global automotive industry. However, CFRP material is made at a high cost of carbon fiber as raw material, so research of production cost reduction into the development of molding equipment and molding process technology related to mass production for the automotive industry is actively administered. Generally, CFRP is known as a high corrosion-resistant material in which no corrosion occurs. However, the investigation of the relationship with corrosion behavior on the roughness of CFRP's conditions according to is rarely studied. In this paper, the surface roughness has conducted three surface roughness conditions given arbitrarily, and the electrochemical evaluation has performed under the electrolysis conditions of 5 wt.% NaCl, which is the salt-water test condition of vehicle parts in automotive industries. Moreover, the samples were analyzed with changes of microstructures by FE-SEM and chemical composition's variation by EDS before and after electrochemical evaluation.

본 연구는 기장 종자의 발아활력 증진과 입모 균일성을 통한 안정적인 생산을 위해 염수선(비중) 종자정선을 활용한 통한 발아율, 유모의 소질 및 포장 출현율을 알아보고자 수행하였다. 1. 염수선에 따른 기장은 비중이 높아질수록 천립중이 증가 하였으며, 표준발아에서는 정선 종자에서 3품종 모두 91% 이상 발아율을 보였으며, 비중선 1.040 g l-1에서 ‘황금’ 98.9%, ‘이백찰’ 99.4%, ‘황실찰’ 98.9%로 가장 높았다. 2. 모 소질을 조사한 결과 초장에서는 비정선 종자에 비해, 정선된 종자에서 평균 초장은 2.0, 2.2 및 1.9 cm 길었고, 엽장에서는 ‘황금’과 ‘이백찰’에서만 유의성이 있었으며, 경직경과 SPAD에서는 염수선 비중에 따른 유의성이 보이지 않았다. 3. 염수선에 정선된 종자의 평균 근장, 근중 및 경중 모두 길거나 무거웠으며, 근장에서는 1.040 g l-1에서 비정선 종자에 비해 2.9, 3.0 및 2.9 cm 길게 나타났고, 근중과 경중에서도 1.040 g l-1에서 가장 무겁게 조사되었다. 4. 포장 발아활력 검정에서는 품종에 따라 평균출아일수에서만 유의성이 있었으며, 염수선 처리에서는 출아율 및 출아율지수에서 고도의 유의성이 나타났다. 3품종 모두 비중선이 높을수록 출아율과 출아율지수가 증가하였고, 비중선 1.040 g l-1 에서 가장 높은 90.7, 85.3 및 92.8% 출아율이 나타났다. 5. 기장의 출아율 증진과 입모 균일성 향상을 통한 생산성 증대를 위해서는 염수선을 통해 비중선 1.040 g l-1에서의 종자를 선별이 유리한 것으로 사료된다.

For the aerospace structural application of high-strength 2xxx series aluminum alloys, stress corrosion cracking(SCC) behavior in aggressive environments needs to be well understood. In this study, the SCC sensitivities of 2024- T62, 2124-T851 and 2050-T84 alloys in a 3.5% NaCl solution are measured using a constant load testing method without polarization and a slow strain rate test(SSRT) method at a strain rate of 10-6 /sec under a cathodic applied potential. When the specimens are exposed to a 3.5% NaCl solution under a constant load for 10 days, the decrease in tensile ductility is negligible for 2124-T851 and 2050-T84 specimens, proving that T8 heat treatment is beneficial in improving the SCC resistance of 2xxx series aluminum alloys. The specimens are also susceptible to SCC in a hydrogen-generating environment at a slow strain rate of 10−6/sec in a 3.5% NaCl solution under a cathodic applied potential. Regardless of the test method, low impurity 2124-T851 and high Cu/Mg ratio 2050-T84 alloys are found to have relatively lower SCC sensitivity than 2024-T62. The SCC behavior of 2xxx series aluminum alloys in the 3.5% NaCl solution is discussed based on fractographic and micrographic observations.

Chlor-alkali (CA) membranes as key materials to generate chlorine gas and sodium hydroxide are composed of sulfonic acid layer (S-layer) and carboxylic acid layer (C-layer) to provide fast sodium ion transport and slow hydroxide ion diffusion, respectively. Aciplex F, a representative CA membrane is made in a double layer form via thermal adhesion of both layers after each single layer film is independently fabricated. Unfortunately, the membrane fabrication induces delamination particularly in their interface as a result of hydroxide ion diffusion occurring during CA operation, leading to rapid increase in electrochemical overpotential. In this study, selective chemical conversion technique was developed to solve the delamination issue. Their effectiveness was proved by applying the same concept to a wide range of PFSA membrane.

Saline water electrolysis is an electrochemical process to produce valued chemicals by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been used as polymer electrolyte membrane (PEM) materials owing to their high sodium ion selectivity and barrier properties. However, sulfonic acid groups in PFSA ionomers are chemically decomposed under a basic catholyte condition, which makes the PEM materials lose their ionic selectivity and Faraday efficiency. In this study, double layered membranes were prepared by anchoring cross-linked hydrocarbon ionomers, as a protection layer to catholyte atmosphere, into the water channels, particularly, located at around the surface of a PFSA membrane. Here, each monomer results in the identical chemical architecture and different free volume content when polymerized.

Saline water electrolysis (SWE) is an electrochemical technology to directly generate valued chemicals such as chlorine gas (Cl2), hydrogen (H2), and sodium hydroxide (NaOH) by applying electric energy. The key materials in SWE are cation exchange membranes with high selectivity to sodium ions under chemically harsh SWE conditions. The representative SWE membranes are perfluorinated double layered membranes composed of perfluorinated sulfonic acid layer and carboxylic acid layer to transport sodium ions rapidly and to prevent the passage of hydroxide ions, respectively. The commercially available membranes are, however, suffering from delamination issues occurring in their interface. In this presentation, delamination-free membrane fabrication processes will be addressed.

Chlor-alkali (CA) membrane process is a commercially useful process to produce valued chemicals such as chlorine, sodium hydroxide and hydrogen via salined water electrolysis using sodium ion (Na+)-selective membranes. The most important issue in CA process is to reduce high energy consumption. A plausible solution is to obtain highly Na+-conductive membranes. The representative membrane materials are chemically stable perfluorinated sulfonic acid (PFSA) ionomers such as Nafion® and Aciplex®. PFSA membranes, but it is necessary to develop alternatives to PFSA membranes. In this study, a sulfonated poly(arylene ether sulfone) copolymer membrane is radiation-grafted with a highly sulfonated poly(styrene) used as a side chain material.

Saline water electrolysis is a representative electrochemical conversion to produce chlorine gas and sodium hydroxide as major products by applying electric power. Perfluorinated sulfonic acid (PFSA) ionomers have been usually used as polymer electrolyte membrane materials owing to high sodium ion selectivity and strong resistance to acidic compounds (e.g., Cl2, HCl and so on) produced in anode. However, PFSA ionomers have been suffering from chemical degradation occurring when exposed under harsh basic condition in cathode. In this study, double layered chlor-alkali membranes were prepared by anchoring crosslinked hydrocarbon ionomer via radical polymerization technique in water channels located in a surface layer of PFSA ionomer membranes and electrochemically evaluated.

ber reinforced polymer (FRP) reinforcing bars for concrete structure have been extensively investigated and a number of FRP bars are commercially available. However, major shortcoming of the existing FRP bars is low elastic modulus compared to conventional steel bars. Because of these reasons, FRP Hybrid Bar which have the concept of material hybridization(synthetic resins, deformed bar, glass fiber etc) for concrete structures have been developed. One of main features of this bar is corrosion resistance and this is important to confirm this anti-corrosion capacity of FRP Hybrid Bar. In this study, galvanic corrosion current behavior of 3 types of specimens, including two types of FRP Hybrid Bars and one conventional steel rebar, was investigated under the 0%, 1.5%, 3% and 6% salt water ratio condition. The result of this study can be used to evaluate the applicability of FRP Hybrid Bar to concrete structures.

염수전기분해(saline water electrolysis) 또는 클로로-알칼리 막공정(chlor-alkali membrane process)은 양이온교환 막과 전극으로 구성되는 전해셀에 전기를 가하여, 고순도(> 99%)의 고부가가치 화합물(예 : 염소, 수소, 수산화나트륨)을 직 접 제조하는 화학공정이다. 염수전기분해의 경제성은 동일한 양의 화합물을 생산하기 위해 투여되는 에너지 소비량을 저감 시킴으로 달성될 수 있다. 이러한 이슈는 전해질이나 전극의 고유 저항을 줄이거나, 전해질과 전극 사이의 계면 저항을 감소 시킴으로 달성시킬 수 있다. 본 연구에서는 전자빔 동시조사법을 사용하여, 높은 화학적 안정성을 지닌 탄화수소계 술폰산 이 오노머 막의 표면에 높은 이온선택성을 갖는 고분자를 접목 시키는 시도가 이루어졌다. 이를 통해, 고분자 전해질 막의 이온 전도성을 보완함과 동시에, 전극과의 계면 저항을 감소시켜, 전기화학적 효율 향상이 이루어짐을 관찰하였다.

The Chlor-alkali (CA) membrane cell is a major electrolysis system to produce valued chemicals such as chlorine gas and sodium hydroxide. The CA membrane process has been attracted in the industries, since it has relatively low energy consumption when compared with other CA processes. The key component in CA process is perfluorinated sulfonic acid ionomer membranes, which provide ion-selectivity and barrier properties to produced gases. Unfortunately, there is limited information to determine which factors should be satisfied for CA applications. In this study, the influences of PFSA membranes on CA performances are disclosed. They include ion transport behaviors, gas evolution capability, and chemical/electrochemical resistances under CA operation conditions.

Salined water electrolysis is an electrochemical reaction to produce chlorine gas and sodium hydroxide as major products from salined water. Perfluorinated sulfonic acid (PFSA) ionomers and their derivatives have been usually used as polymeric electrolytes with high sodium ion selectivity and barrier property to chlorine and hydrogen gases. In spite of their industrial importance, there is little information on the relationship of their chemical features and electrochemical performances. In this study, membrane requirements for salined water electrolysis are described and fundamental and electrochemical characteristics of PFSA and hydrocarbon ionomer materials are compared each other. The obtained results are expected to provide membrane material design factors for low energy-consuming salined water electrolysis.

Salined water electrolysis is an electrochemical reaction to produce chlorine gas and sodium hydroxide as major products from salined water. Perfluorinated sulfonic acid (PFSA) ionomers and their derivatives have been usually used as polymeric electrolytes with high sodium ion selectivity and barrier property to chlorine and hydrogen gases. In spite of their industrial importance, there is little information on the relationship of their chemical features and electrochemical performances. In this study, fundamental characteristics of commercially available PFSA family materials are compared each other. Their electrochemical performances are evaluated in the same salined water electrolysis cell. The obtained results are expected to provide membrane material design factors for low energy-consuming salined water electrolysis.

PURPOSES: This study aims to establish the priority of introducing anti-icing spray system for regions of the National Highways in South Korea. Using this study, a logical plan for instituting such an anti-icing spray system can be established for the National Highways METHODS : The Analytical Hierarchy Process (AHP) was employed to prioritize the implementation of an anti-icing spray system on Korean highways. For this purpose, an existing scoring table developed by the Ministry of Land, Infrastructure Transport Affair was slightly modified in order to reflect recent trends in winter maintenance. A survey was conducted to gather the preferences regarding the developed hierarchy of road experts and agencies. Finally, the final score was produced by integrating the scoring results with estimated weights for each evaluation criterion. RESULTS: In general, Honam and the metropolitan areas have relatively high priority while other areas such as Chungcheong, Young Nam, and Gang Won appear to be uniform in importance in terms of establishing an anti-icing spray system. This result may indicate that historical weather data and traffic volumes are significant factors in deciding in winter maintenance polices CONCLUSIONS : In this study, useful insights are suggested regarding winter maintenance by simultaneously performing rapid snow removal and proactive treatment. Issues of resource allocation may be potential research items in the field transportation engineering.

The pickling brine generated from the salting process of kimchi production is difficult to treat biologically due to very high content of salt. When pickling brine is treated and discharged, it cannot satisfy the criteria for effluent water quality in clean areas, while resources such as the salt to be recycled and the industrial water are wasted. However, sterilization by ozone, UV and photocatalyst is expensive installation costs and operating costs when considering the small kimchi manufacturers. Therefore there is a need to develop economical process. The study was conducted on the sterilization efficiency of the pickling brine using electrochemical processing. The electrochemical treatment of organic matters has advantages over conventional methods such as active carbon absorption process, chemical oxidation, and biological treatment because the response speed is faster and it does not require expensive, harmful oxidizing agents. This study were performed to examine the possibility of electrochemical treatment for the efficient processing of pickling brine and evaluated the performance of residual chlorine for the microbial sterilization.

팥의 건강기능성이 확인되면서 빵, 떡, 빙수, 죽, 과자류, 혼반용 등 다양한 용도 로 그 사용량이 크게 증가하고 있다. 하지만 국내에서 팥의 자급률은 약 13%로 수 입의존도가 매우 높은 작물이다. 팥바구미는 팥 종실의 품질과 이용성 제고에 가장 큰 영향을 미치는 인자의 하나 로 농가에서 생산한 팥은 대체로 상온에서 방치상태로 보관됨으로 이듬해 봄철 (5~6월)에 대부분의 종실로부터 팥바구미가 출현하여 종실을 사용할 수 없는 상태 에 이르게 된다. 이처럼 자가생산한 팥이 팥바구미로부터 큰 피해를 받게 되는 것은 생산자가 팥바구미의 발생생태에 관한 지식부족에 기인된다. 팥바구미는 팥의 성 숙기에 산란하여 종실 안으로 들어감으로 수확한 팥 종실은 이미 팥바구미가 감염 된 상태이며, 감염된 팥 종실을 상온에 방치하면 종실 안에 침입한 팥바구미의 유충 이 발육을 계속하여 봄철에 성충으로 출현하여 밖으로 나오게 된다. 따라서 수확한 팥 종실이 팥바구미에 얼마나 감염 되었는지를 사전에 판별할 수 있다면 팥 종실의 안전관리 및 보관에 큰 도움이 될 것이다. 그리하여 본 연구는 팥 종실을 팥바구미 에 1일간 접종·분리후 1, 4 및 8일 경과한 팥 종실을 0, 3, 6, 9 및 12%의 염수선으로 부유하는 립수를 조사하여 팥바구미에 의한 종실의 감염여부를 진단하고자 하였 다. 팥바구미에 팥 종실의 무게는 초기에는 증가하였으나, 나중에는 감소하였고, 염수선 농도에 따른 팥 종실의 부유립은 1DAS의 경우 1.0%에서 7.0%로, 4DAS의 경우 7.3%에서 10.7%로, 8DAS의 경우 10.3%에서 13.7%로 염수선 농도가 높아 질수록 부유립의 수가 증가하였다. 따라서 염수선을 이용하여 팥종실의 팥바구미 감염여부를 효과적으로 판별할 수 있는 것으로 여겨졌다.

본 연구에서는 딸기의 냉장 및 상온 저장 시 일반세균, pH, color, firmness 등의 품질특성에 있 어 염수 세척에 따른 영향을 분석하였다. 시료는 세척하지 않은 대조구, 염수세척 시료구, 염수세척 후 물기제거한 시료구 세 가지 종류로 준비하였다. 일반세균의 경우 염수세척 후 물기제거한 경우 에 염수세척 시료구와 비세척 대조구에 비해 세균수가 저감화되었으며, 대수증식기가 나타나지 않 았다. pH의 경우, 비세척 대조구와 염수세척 시료구에서는 다소 감소했으나, 염수세척 후 물기를 제거한 시료구에서는 거의 변화가 없는 것으로 나타났다. 적색도는 비세척 대조구와 염수세척 후 물기제거 시료구에서 저장기간이 경과함에 따라 증가되었으나, 염수세척 시료구에서는 감소되었다. 경도의 경우 4℃에서 저장했을 때, 저장 간에 큰 변화를 보이지 않았다. 결론적으로 딸기를 염수세 척하여 물기를 제거할 경우, 저장기간을 크게 연장할 수 있을 것으로 사료된다.