This study was carried out to optimize the filtration, clarification, anti-browning processing conditions of clear pear juice and to investigate changes in antioxidant activity of pear juice produced through different heating treatment. For the filtration with cheese cloth, filter paper, or centrifugation (10 min at 3,000 rpm), the pear juice was most efficiently filtered with centrifugation because it showed the highest lightness (L value) and lowest yellowness (a value). Among various clarifying agents, 1% of gelatin or bentonite clarified effectively pear juice but tannin or egg albumin did not. Among anti-browning agents (0.1%) like L-ascorbic acid, NaCl or citric acid, L-ascorbic acid prevented the browning of pear juice with the lowest browning index value (2.62), compared to that of NaCl (2.74), or citric acid (2.87). Fructose, sucrose, glucose and sorbitol were present in the pear juice, the fructose and glucose contents increased but that of sucrose decreased in the heated pear juice. The total polyphenol content of the heated pear juice significantly increase, and did the total flavonoid contents in the clear and heated pear juice. The DPPH radical scavenging activity and nitrate scavenging activity were higher in the clear and heated pear juice than in the fruit crush.
This study is based on the electrochemical theory which aims to get the quantitative evaluation about corrosion protection of Zn-Sn metal spray method. The various existing corrosion resistance method and various mixture ratio of Zn-Sn metal spray method is applied with structural steel which is measured change of polarization resistance and corrosion potential. So corrosion protection of Zn-Sn metal spray method is tested.
Consequently, coating side of Zn-Sn metal spray method was lower than electric potential of a structural steel adhesion side. So, Galvanic Protection of Zn-Sn metal spray found that structural steel advanced system. Accordingly, Zn-Sn metal spray method is expected as corrosion protection technology excellent in corrosion prevention of structural steel.
The purpose of this study is to evaluate the corrosion protection properties of Zn/Sn metal spray method according to the contents ratio of Zn and Sn by CASS test. Also, the corrosion protection life of Zn/Sn metal spray method is evaluated by the comparing between the corrosion properties of Zn metalizing method and Zn/Sn metal spray method using CASS test. As a result, it was confirmed that the optimum content ratio of Zn/Sn in metal spray method is 60:40(65:35) (Zn : Sn volume ratio) in aspect of corrosion protection properties and construction properties. Also, it was confirmed that the Zn/Sn metal spray method had more than 3 times of corrosion protection properties cmparing the Zn matalizing method.
In this study, manufactured of cement mortar using high early strength cement(10 ~ 50 wt%) and blast furnace slag powder(50 ~ 90 wt%), according to compressive strength and flexural strength of hardened cement mortar. XRD and SEM were evaluated utilizing the initial cement hydration properties.
On this study, carbonation rate and W/C ratio were estimated by collecting actual data of each carbonation depth and compression strength from inner wall, outer wall, stair hall, and balcony floor of certain remodeling apartments. Through above tests, this study can be reference data of the method of life time prediction for the apartments that subject to remodel.
The main purpose of this study is to provide fundamental data in reducing thermal cracks of mass concrete by using Urea. Substitution methods of Urea mixed concrete was different from existing substitution method of concrete. Therefore existing research for Urea mixed concrete had no definite criterion in performance evaluation. In this research, setting-up new criteria, Urea/Water ratio, when evaluating experiment results. As result of experiment, Cement Paste flow was increased largely when mixed in addition method. But there were almost no differences in degree of temperature reduction and time-delay.
Blast furnace slag is recycled as high value-added material, while steel slag is difficult to recycle or is recycled as low value-added one relatively due to its expansion collapsability. It's property is caused by the high content of Free-CaO and unstable steel oxides. Currently, a technique to subdivide the process refining is introduced, can be divided into the electric furnace steel slag and reducing steel slag. In this study, Free-CaO in the electric arc furnace slag by the ethylene glycol method for the quantitative evaluation for the expansion to proceed with construction materials, electric arc furnace slag oxidation is to use.
This study proposed the introduction of the block grant in agriculture, forestry, and fishery sectors so that the local governments get greater autonomy in agricultural policy. First of all, theoretical background on block grant was reviewed and present situation in Korea regarding block grant was examined. Four criteria were set to evaluate the eligibility for the block grant. Four criteria imply that block grant is more appropriate with small-scaled similar projects, high locality projects, easily evaluated projects, and easily formula-applied projects. Applying these criteria to the projects subsidized by the national government, appropriate projects as the block grant were selected. Finally, specific operation scheme of the block grant was proposed.
기후변화로 인한 해수면 상승이 우리나라 연안에 장기적으로 큰 영향을 줄 것으로 예측되어 다양한 방법을 사용하여 연안에 대한 해수면 상승의 취약성 평가가 이루어지고 있다. 본 연구에서는 사면이 바다와 접해 해수에 의한 침수가 빈번하여 향후 해수면 상승에 의한 피해가 클 것으로 예상되는 부산의 영도 해안을 대상으로 해수면 상승이 해안에 미치는 영향을 알아보고 그 대책을 마련하였다. 먼저 잠재적 해수면 상승률을 바탕으로 CAD를 이용한 해수면 상승 시뮬레이션을 실시하였으며 다음으로 시뮬레이션결과를 바탕으로 침수범위와 재해위험 지역을 종합적으로 고려하여 피해 예상지역을 추출하였고 최종적으로 침수특성에 따라 지구별로 세분하여 해당 지구에 적합한 대응전략을 수립하였다.
In this study, corrosion potential (Ecorr), corrosion rate, and polarization resistance were measured aimed at inorganic inhibitors (passive film type) and organic inhibitors (absorption type). The experiment was conducted using potentiostat for the variable molar ratio and chloride ion concentration of the components of inhibitors in an aqueous solution of saturated calcium hydroxide targeting corrosion. As a result, it was possible to ensure an anticorrosive performance of at least a 1.2 molar ratio of inorganic inhibitors. Also, the organic inhibitors ensured the prevention of the anticorrosive performance of at least about a 0.3 molar ratio. It also showed the tendency that between polarization resistance and corrosion rate, Ecorr and corrosion rate is inversely proportional to the linear. Conversely, the tendency between polarization resistance and Ecorr is proportional to the linear. Also, a distinct difference in organic and inorganic inhibitors’ relationship to Ecorr, corrosion rate, and polarization resistance was not shown.
This study was performed to confirm physiological activities according to parts of new pear cultivars (Gamcheonbae, Manpungbae, Chuwhangbae, Hanareum) and Niitaka pear. The total polyphenol compound contents of pear peel, flesh and core were 178~235, 95~113, 177~229 mg/100 g as tannic acid equivalent, respectively. There were differences in the contents by cultivars, Chuwhangbae and Hanareum cultivars showed high contents. The total flavonoid contents of the pear peel, flesh and core were 29.2~40.2, 24.3~34.3, 26.9~38.8 mg/100 g, respectively and those of Chuwhangbae and Gamcheonbae cultivars showed comparatively high values. The electron-donating ability was high in Chuwhangbae, Gamcheonbae and in the pear peel (29.7~57.7%), core (29.1~38.2%), flesh (7.6~17.7%), in that order. The nitrate scavenging activity was highest in that pear peel (21.0~49.8%), followed by the core (11.8~16.2%) and flesh (7.8~9.7%), but there was little difference by cultivar.
These researchers are studying on the hydration model suggestion of cement incorporating blast furnace slag in durability prediction of concrete using hydration model. So in this study it measured hydration heat according to replace ratio, water cement ratio using conduction calorimeter to acquire experiment data for experimental verification and verify hydration heat property when blast furnace slag is incorporated.
Recently, it is requests the reduction of self-load at structure and the cross section reduction due to the trend of making higher, larger of buildings. But The experiment of Lightweight concrete is mostly implemented in Laboratory and is rarely implemented in patch plant for application of construction site. therefore, this study will be useful at base, when the lightweight aggregate concrete is applied to construction site. so We had a comparative experiment of physical performance with in laboratory and Batch plant for lightweight aggregate concrete.
To predict the characteristics of chloride ion penetration in the concrete and rebar corrosion prediction for chloride ion permeation, it is important to understand the chloride ion diffusion coefficient. It is possible that the reinforced concrete structures can be predicted accurately by the profile of the position of the rebar chloride ions using a chloride ion diffusion coefficient. On this study, analysis of chloride ion diffusion coefficient experimented in Korea and the effect of changes in the surface chloride ions concentration on chloride attacked durability design was analyzed
To the goal of improving the early compressive strength of the mortar including Ground granulated
blast furnace slag under low-temperature environment, Industrial byproducts including SiO2 and Al2O3 was fired and than 7% of it was added into Ground granulated blast furnace slag. By checking compressive strength and activity index from different mixing rate, in spite of low strength development than OPC 100%, when using firing powder, the expectation of increasing strength by curing time was affirmative
In this study, we investigated the physical properties and thermal behaviors of specimens that applied different mixing ratios of foaming agent to evaluate the possibility of use in the structural elements. We proposed the estimating equation for compressive strength of each mix having different ratio of foaming agent. We also confirmed that the density of cement matrix is decreased as the mixing amount of foaming agent increase up to 0.6% of foaming agent mixing ratio which was observed by SEM. Based on porosity and compressive strength of control mortar without foaming agent, we built the estimating equations of compressive strength for mortars with foaming agent
In this experiment, the high early strength cement containing massive C3S quantity was used to enhance the early strength of cement mortar using admixtures which can accelerate C3S hydration reaction in the condition of room temperature. The measuring items are zero flow, setting times, compressive strength and analysis of MIP & SEM
In this study, in order to comprehend performance of corrosion inhibitor, the experiment study was conducted about corrosion characteristic 3 steps(0.0, 0.6, 1.2) of Chloride by added amount of inorganic(Ca(NO2)2) and organic(DMEA) corrosion inhibitor by the corrosion inhibitor types about 0.6kg/m3, 2.4kg/m3 based on Chloride ion content 1.2kg/m3 for service life prediction of concrete structure by using Poteniostat. As a results, the excellent anti-corrosive performance of organic corrosion inhibitor was seen that absorption types organic corrosion inhibitor has excellent anti-corrosive performance compared to the inorganic nitrous acid corrosion inhibitor by the added amount of corrosion inhibitor