• Advances in concrete construction
• /
• v.11 no.4
• /
• pp.299-306
• /
• 2021

The alkali-silica reaction (ASR) is a highly complex chemical reaction which causes damage to concrete and thus adversely affects the durability and service life. Significant damage can occur in concrete structures due to cracking because of the chemical reactions taking place. Various mineral and chemical additives have been used so far to mitigate ASR and/or to reduce its adverse effects. In this study, ground trachyte and rhyolite provided from Rize-Çağrankaya region, Turkey, were used to investigate their effectiveness in controlling ASR-induced damage by substituting them with cement at certain ratios. In this context, initially the possible use of trachyte and rhyolite as pozzolanas was determined in accordance with BS EN 450-1 and TS 25 standards by considering their pozzolanic activities and then their effectiveness in mitigating the ASR was evaluated as per ASTM C 1567-13. In experimental study, blends of trachyte and rhyolite were prepared by substituting them by cement at 25%, 35%, and 50% percentage. Totally 7 mixes were prepared and three samples of 25×25×285 mm mortar bars were prepared from each batch. The length changes of the mortar bars were determined at the end of 3, 7, 14 and 28 days of exposure. SEM, along with XRD analyses were performed to examine and elementally determine the ASR products that have been formed. The results obtained have shown that ground trachyte and rhyolite used in this study can be used as pozzolanas in concrete and they can also significantly mitigate ASR-induced damage as the substitution ratio increases.

• Transactions of the Korean hydrogen and new energy society
• /
• v.29 no.6
• /
• pp.549-558
• /
• 2018

The overall efficiency depend on the overpotential of the oxygen evolution reaction in alkaline water electrolysis. Therefore, it is necessary to research to reduce the oxygen evolution overpotential of electrodes. In this study, Ni-Zn-Fe electrodes were prepared by electroplating and the surface area was increased by Zn leaching process. Electroplating variables were studied to optimize the plating parameters(electroplating current density, pH value of electroplating solution, Ni/Fe content ratio). Ni-Zn-Fe electrode, which is electroplated in a modified Watts bath, showed 0.294 V of overpotential at $0.1A/cm^2$. That result is better than that of Ni and Ni-Zn plated electrodes. As the electroplating current density of the Ni-Zn-Fe electrode increased, the particle size tended to increase and the overpotential of oxygen evolution reaction decreased. As reducing pH of electroplating solution from 4 to 2, Fe content in electrode and activity of oxygen evolution reaction decreased.

• Textile Coloration and Finishing
• /
• v.31 no.1
• /
• pp.1-13
• /
• 2019

In this study, eco-friendly functional leather was developed by recycling wastes such as eel skin, marigold(Tagetas erecta l.), hinoki cypress(Chamaecyparis obtusa). The hot water extracts of marigold and hinoki cypress leaves were freeze-dried at $-80^{\circ}C$ to prepare colorant powder. The dyeing of eel leather with marigold was carried out to investigate the effects of dyeing conditions, mordanting on dye uptake, color, morphological change, and color fastness. Considering shrinkage of eel leather caused by dyeing, the optimum dyeing conditions were $60^{\circ}C$ of dyeing temperature and 60 min of dyeing time at 1:100 of bath ratio, and color of the dyed eel leather was Y to YR Munsell series. In order to prevent the degradation of leather from microbe, we conducted combination dyeing with marigold and hinoki cypress leave colorants. In this case, the combination dyed eel leathers showed excellent antimicrobial activity with above 99% bacterial reduction rate against S. aurieus and K. pneumoniae. It was confirmed that all of the dyed eel leathers were sufficient to meet the Korean Standard for color fastness of leather products. It can be applied practically for the development of eco-friendly functional leather by utilizing some useful active components extracted from plant resources and by recycling food wastes.

• Journal of the Korean institute of surface engineering
• /
• v.55 no.2
• /
• pp.120-132
• /
• 2022

In the non-cyanide-based electroless Au plating solution using thiomalic acid as a complexing agent and aminoethanethiol as a reducing agent, analysis of each component constituting the plating solution is essential for the analysis of the reaction mechanism. And component analysis in the plating solution is important for monitoring component changes in the plating process and optimizing the management method. Capillary Electrophoresis (CE) method is rapid, sensitive and quantitative and could be readily applied to analysis of Auⁿ⁺ ion, complexing agent and reducing agent in electroless Au plating solution. In this study, the capillary electrophoresis method was used to analyze each component in the electroless Au plating solution in order to elucidate the complex bonding form and the plating mechanism of the non-cyanide-based electroless Au plating bath. The purpose of this study was to establish data for optimizing the monitoring and management method of plating solution components to improve the uniformity of precipitation and stability. As a result, it was confirmed that the analysis of thiomalic acid as a complexing agent and Auⁿ⁺ ions and the analysis of aminoethanethiol as a reducing agent were possible by capillary electrophoresis. In the newly developed non-cyanide-based electroless Au plating solution, it was confirmed that Auⁿ⁺ ions exist in the form of Au⁺ having a charge of +1, and that thiomalic acid and Au⁺ are combined in a molar ratio of 2 : 1. In addition, it was confirmed that aminoethanethiol can form a complex by combining with Au⁺ ions depending on conditions as well as acting as a reducing agent.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.1
• /
• pp.66-74
• /
• 2005

Three experiments were conducted to study the property of xylanase and the effects of xylanase in wheat-based diets on growth performance of broilers, respectively. Experiment 1 was performed in vitro to evaluate the effect of different pH and temperature on xylanase activity, and to evaluate the enzymic stability under different conditions. The results indicated that the optimum temperature and pH for xylanase activity were $50^{\circ}C$ and 4.5, respectively. The activity of enzyme solution was reduced rapidly after the treatment of water bath above $60^{\circ}C$ for 10 min. The enzyme was relatively stable at pH 3.5 to 8.0 and deteriorated when incubated at pH below 3.5. In Experiment 2, a total of 378 d-old male Arbor Acres broilers were randomly distributed to 7 different treatments with 6 replicates (9 birds) in each treatment. The treatments were as follows: (1) corn based diet (CS), (2) wheat based diet (WS), (3) WS+ 0.05% xylanase, (4) WS+0.15% xylanase, (5) WS+0.25% xylanase, (6) WS+0.35% xylanase, (7) WS+0.45% xylanase. The results showed that the body weight and feed/gain ratio of the broilers fed wheat-based diets have been significantly improved (p<0.05) compared to that fed corn-based diet in the first 3 wk. With regard to the wheat-based diets, the xylanase supplementation had a tendency to improve the growth performance in first 3 wk. After 3 wk, no significant difference (p>0.05) was found among all these different treatments. The supplementation of xylanase and the type of diets did not affect the feed intake but increased the concentration of triglyceride in serum. In Experiment 3, a total of 360 d-old male Arbor Acres broilers were assigned to 30 groups with 12 birds in each group randomly. These groups were then randomly distributed to 5 different treatments with 6 replicates within each treatment. The broilers of each treatment were fed one of the diets as follows: (1) Corn based diet, (2) White wheat based diet (WW) (3) White wheat based diet+0.25% xylanase, (4) Red wheat based diet, (5) Red wheat based diet+0.25% xylanase. The results showed that the body weight and feed/gain ratio had been significantly improved (p<0.05) by xylanase supplementation in the first 2 or 3 wk. The effect of xylanase in red wheat diet is a little higher than that used in white wheat diet. From the results of the present experiments, it can be concluded that the supplementation of Aspergillar xylanase can improve the performance of the broilers fed the wheat-based diet.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.18 no.2
• /
• pp.31-44
• /
• 1990

This study was carried out to investigate the changes of rural residential environmemts accompanied by the rural village improvement projects. The results of this study can be a guidoline for further betterment works of rural village envirnments. This sutdy is composed of the survey of two major parts, one Is the interview of the residents and the survey of existing conditions of residential environments, and the other is a questionnaire survey of the mental image, preference and satisfaction for each village residential environments. Based on preliminary investigation, five rural villages, located In Kyungsamgun., Kyungbuk province, were selected as sutdy sites. The major results are summarized as follows; 1. In socio-cultural enveronments, the ratio of compound and non - agricultural household are increased with the modernization of rural villages. On the ocher hand, the numbers of neighbor's association are considerably decreased. This means the traditional community of korean rural villages are diminishing. 2. In physical environments, the ratio of improved western type gouses are increased In modprnized villages. And the modernization is most remarkable in the palls of fences and gardens. 3. By the result of the analysis of residfnt's environmental image and preference, the image scores of urban, formal, mdoern, etc. are showed to be high. And the preference is also high in modernized villages. But in general, the Preference for the village environment is comparatively low in all villages. This means the improvememt work should be continuous and systematic. 4. By the result of stepwise regression analysis, the variables, affecting the preference of village environment. are regularity, familiarity, amount of greenery, beauty of surrounding scenery, convenience, cleanness, etc. The R2s of the perference models were 0.4486 ∼0.9395, Which are considered to be high. 5. In the satisfaction for each residences, the toilets are mostly dis - satisfying. With the modernization of vilelages, the needs for environmental quality by residents are increased. 6. In the satisfaction for village enveironments, the satisfaction level is most low in service facilities, such as public bath, barbershop. And the satisfaction for the scenic beauty, the amenity of surrondings, and the com munity of the traditional villages, are commparatively high in conventional villges. 7. The imporvement works, based on the characteristics of each rural villages, are recommended. And the tradition of Jung - ja tree spaces and harmony with surrounding landscape of traditional villages, must be conserved with good regards.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.8
• /
• pp.1115-1120
• /
• 2002

The effects of seed-associated or free linseed oil on fermentation characteristics and long-chain unsaturated fatty acids composition, especially the formation of conjugated linoleic acid (CLA) and octadecenoic acid (trans-11 $C_{18:1}$, $t-C_{18:1}$) by mixed ruminal bacteria were examined in vitro. Concentrate (1% of culture solution, w/v, as-fed basis) with ground linseed (0.6% of culture solution, w/v, DM basis) or linseed oil as absorbed onto ground alfalfa hay was added to 600 ml mixed solution consisting of strained rumen fluid and artificial saliva at the ratio of 1:1 in a glass culture jar. The culture jar was covered with a glass lid with stirrer, and placed into a water-bath ($39^{\circ}C$) and incubated anaerobically up to 24 h. Seed-associated or free linseed oil did not significantly affect the pH and ammonia concentration in the culture solution. Molar percent of acetate tended to increase while that of propionate decreased with the addition of free oil treatment throughout the incubation. Differences in bacterial number were relatively small, regardless of the form of supplements. Decreasing trends in the compositions of linoleic acid ($C_{18:2}$) and linolenic acid ($C_{18:3}$) but increasing trends of stearic acid ($C_{18:0}$), $t-C_{18:1}$ and CLA compositions were found from culture contents up to 12h incubation when incubated with both ground linseed and linseed oil. The compositions of $C_{18:0}$, $C_{18:2}$ and $C_{18:3}$ were greater but those of oleic acid ($C_{18:1}$), $t-C_{18:1}$ and CLA were smaller in a culture solution containing ground linseed than those containing linseed oil. The ratio of $t-C_{18:1}$ to CLA was lower in the culture solutions containing linseed oil up to 12h incubations as compared to those containing ground linseed.

• Science of Emotion and Sensibility
• /
• v.19 no.4
• /
• pp.3-12
• /
• 2016

The aim of this study is to find the optimal combination dyeing condition for the enhancement of dye uptake and union dyeing of the composite material fabric made of triacetate and quick drying PET blended yarn. For the experiment, fabrics were one-bath combination dyed using the mixed dye of E-type disperse dye(C.I Disperse red 50) and S-type disperse dye(C.I. Disperse red 92) to measure dyed fabric's dye exhaustion, dye uptake, color and color difference according to the diverse conditions including dying temperature, time and mixed ratio of the dye. Dye equilibrium of combination dyeing occurred in $100^{\circ}C$, but by comparing dyed fabrics' K/S value and surface color, it was found that $120^{\circ}C$ was where the manifestation of color of triacetate and quick drying PET was identical. Mixed dye exhaustion and dye uptake merely changed as dyeing time increased, but color became more uniform. Therefore, it can be concluded that by using combination dyeing method, and by using the mixed dye which the mixing ratio of S-type dye and E-type dye is appropriately controlled, dye uptake can be improved compared to using single dyeing regardless of the color of E-type dye.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.8
• /
• pp.1113-1120
• /
• 2011

Enzymatic interesterification was conducted with the palm mid fraction (PMF) and stearic ethyl ester for 1, 5, and 9 hr at 46$^{\circ}C$. The reaction was catalyzed by Lipozyme TLIM (2, 3, and 4% by weight of total substrates) in a shaking water bath at 180 rpm. As the reaction continued, oleic acid (C18:1) content at the sn-2 position decreased, whereas saturated fatty acid (C16:0 and C18:0) content increased. In the high performance chromatography analysis, 1,3-dipalmitoyl-2-oleoyl glycerol content decreased, whereas 1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl glycerol (POS) content increased up to the reaction equilibrium. The rate of acyl migration increased with increasing molar ratio and enzyme load as well as reaction time. The optimal reaction conditions for maximizing POS content (53.5 area%) and minimizing acyl migration (23.1 area%) were obtained with a PMF : stearic ethyl ester=1:2 (molar ratio), Lipozyme TLIM 3 wt%, and a reaction time of 5 hr.

• Journal of Korean Academy of Nursing
• /
• v.30 no.6
• /
• pp.1543-1555
• /
• 2000

Home health care is moving into a set of new realities. An era of competition and cost containment has arrived. Before nurses are able to contain costs or describe the relationship between nursing activities, cost must be accurately measured based on the nurse's workload. Nurses in home health care usually desire to measure expenses for one of three reasons : reimbursement, management, or research. The purpose of the study was to investigate the work input by Registered Nurse in each of the home health care activities by relative value units and identify the factors affecting the nurses' total work input in health care services. To measure the work input by nurses, work was defined by four dimensions: time, physical effort, mental effort, and stress. This study used a descriptive-correlational design. Data collection consisted of two phases. In phase I, data on home health activities performed by nurses were collected. In phase II, data on nurses' time, physical effort, mental effort, and stress in each of home health care activities discovered phase I were collected. In this method, the respondent was asked to rate a service in relation to a reference service using a ratio scale. The sample included 39 home health care nurses. The results of the study indicated that home health care activities performed by the nurses were in 10 categories and 69 items. Measuring the relative work inputs in each of home health care activities, and foley catheterization was selected as the reference to service. In terms of time and physical effort dimensions, full bath service was rated as the most strenuous among 69 activities by the respondents, and intramuscular injection was rated as least. It was found that emergency treatment required the highest mental effort and the highest stress, while blood sugar tests required the lowest mental effort. Approximately 91.3% of the variance in total work input was accounted for by the linear combination of time, physical effort, mental effort judgement, and stress. Examining the regression coefficients of those variables, physical effort, time, and stress were found as the predictors which were significantly associated with the total work of nurses in home health care. Professional nursing's next step in the conundrum of economic volatility is to develop a tool to reflect the interaction of functional deficiency and direct professional nursing care. And this will be a more accurate predictor of nursing resource use and ultimately a great forcaeter cost.