• Food Science of Animal Resources
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• v.34 no.6
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• pp.769-776
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• 2014

The goat placenta was fermented by Bacillus subtilis and the optimal fermentation parameters of strongest antioxidant capacity of peptides were obtained using response surface methodology (RSM). The effects of fermentation time, initial pH value and glucose content on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the goat peptides were well fitted to a quadric equation with high determination coefficients. According to the data analysis of design expert, the strongest DPPH radical scavenging capacity value was obtained with the following conditions: content of glucose was 2.23%, initial pH value was 7.00 and fermentation time was 32.15 h. The DPPH radical scavenging capacity commonly referring antioxidant activity showed a concentration dependency and increased with increasing peptide concentration. The effects of temperature and pH were assessed to determine the stability of antioxidant peptides prepared from goat placenta. Antioxidant peptides showed good stabilities when temperature was lower than $70^{\circ}C$. However, the antioxidant peptides lost antioxidant activities rapidly under alkaline and excessive acid condition. Ultrafiltration technique was performed to separate fermentation broth with different Mw (molecular weight). It was found that peptides in the range of < 3 KDa mainly accounted for the antioxidant activities.

• Membrane Journal
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• v.22 no.3
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• pp.178-190
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• 2012

Flat sheet membranes were prepared with polysulfone (PSF) by an immersion precipitation phase inversion method. Membranes were prepared with PSF/N-methylpyrrolidone (NMP)/polyvinylpyrrolidone (PVP)/phosphoric acid casting solution and water coagulant. By using the successive process of the vapor-induced phase inversion (VIPS) followed by the nonsolvent-induced phase inversion (NIPS), the effect of phosphoric acid addition to casting solution on morphology and permeability of membrane was studied. The mean pore size, the porosity, and the water flux of membranes were increased by the addition of small amount of phosphoric acid. Furthermore, the morphology of the prepared membranes were changed from a dense sponge-like structure to highly enhanced asymmetric structure. PSF/NMP/PVP/phosphoric acid/2-butoxyethanol (BE) casting solution were prepared and cast the successive VIPS-NIPS process with same experimental condition. Due to the addition of BE to casting solution, the mean pore size and almost 0.1 ${\mu}m$ and the water flux increased about 10 to 12 $L/cm^2{\cdot}min{\cdot}bar$.

• Membrane Journal
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• v.30 no.1
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• pp.21-29
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• 2020

In this study, we have established the optimum design condition of pore-filled anion-exchange membrane for all-vanadium redox flow battery (VRFB). From the experimental results, it was proven that the membrane design factors that have the greatest influence on the charge-discharge performance of VRFB are the ion exchange capacity, the porosity of substrate film, and the crosslinking degree. That is, the ohmic loss and the crossover of active materials in VRFB were shown to be determined by the above factors. In addition, two methods, i.e. reducing the ion exchange capacity at low crosslinking degree and increasing the crosslinking degree at high ion exchange capacity, were investigated in the preparation of pore-filled anion-exchange membranes. As a result, it was found that optimizing the crosslinking degree at sufficiently high ion exchange capacity is more desirable to achieving high VRFB charge-discharge performances.

• Restorative Dentistry and Endodontics
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• v.12 no.1
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• pp.51-64
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• 1986

The purpose of this study is to obtain the data of prestep in cavity preparation by observing changed conditions of laser irradiated dental hard tissues. The forty five extracted caries free human molars were divided into three groups and each group into five subgroups. A $CO_2$ laser irradiation was performed each subgroup of group I for one second with output power of 5 W, 10 Wand 20 W. On group II, laser irradiation was done ten times for 0.1 second duration using same power ratings as group I. On group III, laser irradiation was done 0.1 second, 0.2 second and 0.4 second with output power of 50 W. We investigated mineral contents and crater wall of obtained specimens, i.e., laser irradiated teeth, using computer controlled electron probe microanalyzer and scanning electron microscope. The following results were obtained: 1. Both calcium and phosphorus contents in laser irradiated enamel crater wall were increased, and magnesium content was decreased, but these trends were not statistically significant. 2. In laser irradiated dentin, change of mineral content was more significant. 3. In laser irradiated enamel and dentin, there were no significant differences on mineral content change due to irradiation condition and energy density. 4. In scanning electron microscopic study, enamel rods of the crater wall were fused and clefts were observed in parallel with the direction of enamel rod for all groups. 5. In laser irradiated dentin, irregular fusion and clefts were observed. In irradiated teeth with high power and short duration, the locally formed narrow crater wall was observed.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.799-804
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• 2002

Optimum conditions of freeze-dried carrots were determined using response surface methodology. Physicochemical and sensory properties of freeze-dried carrot prepared at different plate temperatures and chamber pressures were evaluated. Drying time increased with decreasing plate temperature and chamber pressure. Rehydration ratio decreased inversely with chamber pressure at low plate temperature, but increased proportionally with chamber pressure at high temperature. Density, color, and sensory off-flavor were not affected by the plate temperature and chamber pressure. Sensory color, tenderness, and carrot flavor increased with decreasing plate temperature, but were not affected by chamber pressure. Based on the drying time, rehydration ratio, and sensory attributes, optimum plate temperature and chamber pressure for the preparation of freeze-dried carrot were determined as $43^{\circ}C$ and 700 micronHg, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.42-46
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• 2003

This research was carried out for searching the treatment conditions of organic acid and heating to prepare oligomers from the carrageenan. The applied treatments were autoclaving, micraowaving, and ultrasonicating with acetate, citrate, lactate, malate, and succinate. Among several physical depolymerization methods, auo-claving treatment was the most effective for hydrolyzing the carrageenan to low molecular compounds such as oligosaccharides. Citrate or malate was the most effective catalyst in hydrolyzing carrageenan to some oligo-saccharides among 5~7 different organic acids. An acceptable autoclaving condition for hydrolyzing carrageenan to oligosaccharides was to treat for 120 min at 110~12$0^{\circ}C$. The maximum depolymerization ratio produced by autoclaving was about 23.0%. The depolymerized carrageenan prepared by autoclaving at 12$0^{\circ}C$ had oligo-saccharides of 5~7 species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1297-1301
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• 2003

The response surface methodology was peformed by central composite design based on drying temperature and time of Citrus, to monitor quality property change caused by drying and make dried products with a good overall palatability. In result, water activity, hardness and softness were affected by drying temperature; water activity decreased and hardness increased with increase of drying temperature. Softness was also high at low temperature and short time of drying. In the range of overall palatability having high score, hardness was shown in 2.01 ∼ 3.20${\times}$10$^{6}$ dyn/$\textrm{cm}^2$ and softness was 62.54 ∼ 146.37 cm/kg. Drying conditions satisfying this range were predicted as 66 ∼ 75$^{\circ}C$ of drying temperature and 8 ∼ 14 hr of drying time.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.54-59
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• 2003

Recently, densified pellet fuel from wood biomass is widely used at North America and Europe as a regenerable and clean carbon neutral bioenergy. High-pressure compaction of sawdust of Hyunsasi-poplar (Populus alba ${\times}$ P. glandulosa) to form a densified fuel was studied. Calorific and elemental analysis were carried out to assess Hyunsasi-poplar clones as fuels. Hot-press process was adopted for compaction of sawdust and compaction was performed under temperature from 100 to 180$^{\circ}C$, at pressure of 250 to 1000 kgf/$\textrm{cm}^2$, and for 2.5 to 10 minutes. Densified fuels were evaluated by its oven-dry density and fines after 5-minute shaking test. The target density and fines of densified fuels were over 1.2 g/$\textrm{cm}^2$ and below 0.5%, respectively. When the press-temperature is over 160$^{\circ}C$, densified fuels with density eve. 1.2 g/$\textrm{cm}^2$ and with fines below 0.5% can be produced. And the pressure over 750 kgf/$\textrm{cm}^2$ was effective for this production. It was found that the optimum press condition for preparation of densified fuel was 180$^{\circ}C$ -1000 kgf/$\textrm{cm}^2$ minutes.

• The Journal of Korean Association of Computer Education
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• v.3 no.1
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• pp.87-95
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• 2000

In current computer education, we have inclined to emphasize information literacy for k-12 students. On the other hand, in spite that teachers are core variable in school education system, we have neglected teacher's education of information and communication technology. In addition, we haven't made a effort to expand preservice teacher's ability to utilize information and communication technology in the teacher's college and the college of education. With these recognitions, we made a diagnosis of problems by analysis of current condition of curriculum of the teacher's college and the college of education and explored the vision of ICT utilization education in k-12 computer education in this study. In addition, we suggested educational objectives and contents based on national requiring standards for ICT in teacher preparation, required ICT capability of preservice teachers for kind of teacher's task and the direction of computer education.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.2 no.1
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• pp.55-66
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• 1995

The goals of nursing education, and the bases for evaluating them depend on the goals of nursing practice. In order to prepare for the coming twenty first century and the meet changing societal demands and health needs, it is necessary to develop a new conceptual framework for future nursing education. While hospitals will still be in significant components of the health care system, will no longer be central focus or dominant influence. Health care services will be more usually delivered at community base. The nursing education required by that new approach must provide for reconsidered about a concept of caring as nursing curriculum. The changes in health care delivery that have occured, now being proposed, for nursing education undergoing its own changes. So the philosophy and objectives of education meed to reconsidering about the caring concept and general nursing. Nurse educators must prepare students to practic in condition of constant change. At the same time nurse educators must emphasize preparation about that. The practice of science of caring in nursing draws on a basic knowledge of the behavioral knowledge, biophysical processes, pathological processes, nursing skills and procedures and various treatment regimes and problem solving to help decision making in nursing situations. The concept of care is probably one of the least understood ideas used by professional and nonprofessional people, yet it is probably one of the most improtant concepts to be understood by nursing. Human caring and human relationships are closely interrelated. Humn caring remains an essential dimension of professional work and the science of caring as essental to the discipline of nursing. It is expected that the objectives of nursing education will be accomplished when the course and content of the curriculum are based on this conceptual framework. One recurrent education goal with some consistency is that of equipping the student with the necessary skills to live effectively and productivly in the world of tomorrow. In the new vision we are developing, professional education must also include exposure to liberal arts, encouragement of critical thinking, and a moral context for advanced professional education that is based upon a contextual health policy and caring science educational model.