• Journal of Animal Science and Technology
• /
• v.51 no.2
• /
• pp.143-154
• /
• 2009

(Y $\times$ L) $\times$ D-crossbred gilts and barrows weighing $80.2\pm0.2$ kg were fed a "medium-energy" (ME) or "low-energy" (LE) diet (3.2 vs 3.0 M cal DE/kg) and slaughtered at 110, 125, or 138 kg, after which physicochemical and sensory quality traits of major primal cuts of resulting carcasses were analyzed, under a 2 (sex) $\times$ 2 (diet) $\times$ 3 (slaughter weight; SW) factorial arrangement of treatments. The ADG and ADFI were greater (P<0.01) in barrows than in gilts and also in 125- and 138-kg vs 110-kg SW. Moreover, ADG and gain:feed were greater in ME vs LE (P<0.01), whereas ADFI was greater in LE vs ME (P<0.01). Backfat thickness, which increased with increasing SW (P<0.01), was not affected by sex or diet. Carcass marbling score was greater (P<0.01) in gilts and LE than in barrows and ME, respectively. Carcass quality grade, which was superior in LE vs ME, was not affected by SW, whereas the yield grade decreased abruptly between 125- and 138-kg SW primarily due to the upper limit of carcass weight imposed on the A and B grades. Physicochemical characteristics including pH, drip loss, and variables pertaining to color of belly, ham, and loin were not affected significantly by any of the treatment factors, albeit statistically significant in some cases, in terms of quality criteria. In sensory evaluation, the acceptability of fresh belly was not influenced by any of the treatment factors. Marbling score of fresh ham was greater in LE vs ME (P<0.01) and tended to increase between 110- and 125-kg SW (P=0.10); in loin, the increase of this variable between the two SW was significant (P<0.01). Following cooking, LE was superior to ME in the acceptability in belly and ham, but the effect of SW was insignificant in any of the sensory quality traits evaluated in this study in any of the three major primal cuts. In conclusion, the present results suggest that SW can be increased to up to 138 kg without compromising carcass quality and that LE has some beneficial effects on quality of the whole carcass and the major primal cuts.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.2
• /
• pp.129-137
• /
• 2006

A study was conducted to investigate the behavior of pollutant forms at each area in the sewage treatment plant by natural purification method. The sewage treatment plant by natural purification method that consisted of aerobic and anaerobic area was constructed. The efficiency of sewage treatment depending on the operation time, the loading amount of pollutant season variation were investigated. The removal amount of BOD, COD, TOC and SS in the aerobic area was significantly increased as the treatment proceeded. Decreased BOD, COD, TOC, SS, T-N and T-P depending on the loading amount of pollutants in the aerobic and ananerobic area were mostly insoluble BOD (IBOD), insoluble COD (ICOD), soluble TOC (STOC), volatile SS (VSS), dissolved T-N (DTN) and dissolved T-N (DTP) types, respectively. The removal efficiency of BOD, COD, TOC, SS, T-N and T-P in hot season (summer and autumn) were more than that in cold season (spring and winter). The removal efficiencies of BOD, COD, TOC, SS, T-N and T-P of the effluent were about 92, 89, 73, 95, 46 and 84% in all seasons, respectively.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.15 no.2
• /
• pp.67-75
• /
• 2012

Carbon-dioxide capture and storage (CCS) process is consisted by capturing carbon-dioxide from large point source such as power plant and steel works, transporting and sequestrating captured $CO_2$ in a stable geological structure. During CCS process, it is inevitable of introducing impurities from combustion, capture and purification process into $CO_2$ stream. Impurities such as $SO_2$, $H_2O$, CO, $N_2$, Ar, $O_2$, $H_2$, can influence on process efficiency, capital expenditure, operation expense of CCS process. In this study, experimental apparatus is built to simulate the behavior of $CO_2$ transport under various impurity composition and process pressure condition. With this apparatus, $N_2$ impurity effect on $CO_2$ mixture transportation was experimentally evaluated. The result showed that as $N_2$ ratio increased pressure drop per mass flow and specific volume of $CO_2-N_2$ mixture also increased. In 120 and 100 bar condition the mixture was in single phase supercritical condition, and as $N_2$ ratio increased gradient of specific volume change and pressure drop per mass flow did not change largely compared to low pressure condition. In 70 bar condition the mixture phase changed from single phase liquid to single phase vapor through liquid-vapor two phase region, and it showed that the gradient of specific volume change and pressure drop per mass flow varied in each phase.

• Journal of Animal Science and Technology
• /
• v.50 no.4
• /
• pp.499-508
• /
• 2008

This study was conducted to evaluate the effect of bio-starch from corn processing to replace dried whey in weaned pigs. A total of 120 crossbred [(Landrace×Yorkshire)×Duroc] pigs were weaned at 21 days of age weighing 6.01±0.34 kg in average. Five week feeding trial consisted of phase 1(0~2 wks) and phase 2(3~5 wks). Dietary treatments included 1) CON(basal diet), 2) BS5(whey 5%, partial substitution of bio-starch), 3) BS10(whey 10%, partial substitution of bio-starch) and 4) BS15(whey 15%, partial substitution of bio-starch). There were four dietary treatments with six replicate pens per treatment and five pigs per pen. During the overall period, there were no significant differences in the ADG(average daily gain) and gain/feed ratio among the treatments(P>0.05). However, the ADFI(average daily feed intake) was higher in BS5 and BS15 treatments than in CON treatment(P<0.05). At the 2nd week, dry matter and nitrogen digestibility were increased(quadratic effect, P=0.03 and P=0.01, respectively; cubic effect, P<0.001 and P=0.01, respectively) with the highest at 10% of bio-starch inclusion in the diets. At the last week of the experiment, dry matter, nitrogen and energy digestibility were increased(P<0.05) with the highest at 5% of bio-starch inclusion in the diets. At the 2nd week total protein concentration was increased(linear effect, P=0.04; cubic effect, P=0.01) with the highest at 10% of bio-starch inclusion in the diets. Also, BUN(blood urea nitrogen) was increased(linear effect, P=0.01) as the level of bio-starch inclusion increased in the diets. Fecal consistency score was inclined to lowers CON treatment than other treatments. In conclusion, the result of trial indicates that bio-starch can be included at the level of 5~10% of weaning pig diet replacing part of the dried-whey, and digestibilities were positively affected by bio-starch at growth stage.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.21 no.1
• /
• pp.1-6
• /
• 2001

This experiment was conducted to evaluated the effect of maturity at harvest on the changes in quality of round baled rye silage at forage experimental field of Grassland and Forage Crops Division, National Livestock Research Institute, RDA, Suwon in 1998. The experimental design was a split-plot design with three replications. The main plots were three different harvest stages : boot, heading and flowering stages, and the subplots were days after ensiling : 1, 2, 3, 5, 10, 30, 45, and 60 days. The wilting period of boot, heading and flowering stages were 1, 0.5 and 0.5 days, respectively. The final pH of rye silage was higher in the order of flowering, boot and heading stages. And pH of flowering stage began to change at early fermentation period, but that of boot and heading stages was delayed 1~2 days. Ammonia-N content of boot stage was highest. and that was increased as fermentation progressed. But Ammonia-N of heading stage was decreased to 30 days. then that was increased after 45 days fermentation. Among fermentation periods, inside temperature of deep place was not affected by external temperature. And that of deep place was increased to 3$0^{\circ}C$ at early fermentation. then decreased as fermentation progressed. However surface temperature was affected by external temperature after 10 days. Acetic acid content was not changed with 5 days by harvest stages, but that of boot stage was increased after 10 days. Butyric acid of boot stage was increased after 5 days. but that of heading stage was increased after 10 days. However lactic acid was increased from 1~2% to 6~8%. Lactic acid bacteria (LAB) of heading and flowering stages were highest at 5 days fermentation, and that of boot stage was highest at 10 days fermentation. The results of this study indicate that fermentation of round baled rye silage occur within 5 days. Therefore, any modification should be applied with an 5 days for high quality of round baled rye silage.

• Journal of The Korean Association For Science Education
• /
• v.33 no.7
• /
• pp.1431-1449
• /
• 2013

This study is based on the assertion that science museums should consider visitors' views and expectations as they are not satisfied in many cases. In this study, we investigated 31 scientifically gifted students and 177 science high school students about their image of science museums. Using the questionnaire, it was found that only 51% of students visited science museums; however, the average number of visits was 4.2. This means that students tended to re-visit after the first visit of the science museum. Students had a 'good' image of science museums when they incurred hands-on experiences and observed new, interesting, curious and funny exhibits. And students had a 'bad' image of science museums due to the following aspects: lack of new and interesting exhibits, information and guide, diverse contents, and hands-on experience; deficiencies in environment; and inadequacy of the management, operation and composition of exhibits. Therefore, they hoped that science museums will provide more hands-on experiences and experiments, new and interesting exhibits, systematic management and composition of exhibits, information and guides, and a good environment. So science museums need to pay special attention to aspects like management, information guides and environment for the first-time visitors. Based on the above results, we suggested "Directions for a good science museum based on students' views". While asking students what topics they wanted to know and learn in a science museum, each student was given the choice of four topics; eventually, 2.9 answers overlapped for each topic. When classifying students' topics into four main themes for the Gwangju National Science Museum, the order from the most popular theme to the least one was 'science in everyday life', 'ocean/space/future science', 'light and science', and 'culture, art and science'. Among the topics mentioned by students, only 37% are exhibited in Seoul, Gwacheon, Daejeon, or Gwangju science museums. We hope that the results and research methods will be used for evaluation, re-construction, and reinvigorated presentation of science museums.

• Journal of Korean Society of Environmental Engineers
• /
• v.39 no.12
• /
• pp.664-671
• /
• 2017

Non-point source pollution is the emission source that unspecifically releases pollutants to water system from unspecific places such as cities, agricultural lands, mountains, and construction sites and its discharge path is not easily identified. Also, it is difficult to design and manage the reduction facilities for the emission quantity is primarily affected from weather conditions like rainfall. Since 2006, the significance of non-point source pollution reduction has been grown in Republic of Korea and this reinforces needs for the installation of reduction facilities. However, because the standards for the installation details and reduction efficiency are not clarified by law, people are preferring technologies that do not require particular maintenance and high expenses. The purpose of this study is to examine and maintain the efficiency of non-point source pollutants reduction facility which uses expended polypropylene as a media. The higher the depth of the media, the less range of variations in the reduction efficiency was observed and the final efficiency was also increased. When the media depth was 60 cm, the average reduction efficiency was 94% and 90% where linear velocities were 10 m/hr and 20 m/hr respectively. The results from 180 minutes operation in 10 m/hr and 20 m/hr of linear velocities were slightly different in head loss changes which were caused by media depth variations. The backwash experiments which were conducted in triplicate showed the reduction efficiency decreased as the time went on because of the media clogging. However, it was found that after the backwashing the reduction efficiency was increased as effective as the efficiency of the initial filtration.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.44 no.6
• /
• pp.26-39
• /
• 2016

This research paper explores the process of developing skateboarding spaces in urban parks. Skateboarding is one of the most popular sport activities representative of urban parks. This research paper will analyze the process of introducing skateboarding activities into park spaces and their acceptance by the general public as well as derive meaningful general implications for park space development planning. The research method is a discourse analysis of newspaper articles regarding skateboarding issued between the 1960s and 2010s. These articles are the main resources to show the creation of a skateboarding culture, generation of skate park spaces, and the extinction of these spaces during the research period. The result of this research is as follows. There are reasons that allowed for the creation of skate park spaces in urban parks. First of all, positive associations that people have regarding skateboarding have influenced the park's users and operators' decisions that a park is proper space for skateboarding activities, and the agreement to remodel the park space. Secondly, skate parks became a space for multiple-uses that can be shared with other emerging sports, which resulted in a building boom of skateboarding spaces in urban parks. Thirdly, urban parks and their new culture of active sports became a marketing tool used by local governments to attract new inhabitants to their new towns. On the contrary, there are three main reasons for the deterioration of skate parks. First of all, within parks in which skateboarding activities collided with other park usage, the skate parks disappeared. Secondly, skate parks built specifically for competitive skateboarding events and without consideration of casual skaters disappeared, as these facilities were not sustainable for use in the long term. Thirdly, the golden age of skate park skateboarding did not last long, as skateboarding trends shifted from trick performance to street skating, where skate parks are no longer needed. For this reasons, the exclusive use of park space for skateboarding activities has faded from public interest. The findings of this research suggest how sport activities should be introduced to urban parks. At first, each park's management needs to identify a sport suitable for long-term development, and not only plan for temporal events or follow fleeting trends. Secondly, the park's management systems should reflect a type of sport activity that would not only be popular at the beginning of the spaces development, but also take into consideration how these activities will change over time. Lastly, in cases where there are conflicts between sport activities and other activities in urban parks, attempts should be made to suggest feasible solutions other than the liquidation of sport spaces. This study explains the development process of sport spaces offered in urban parks, by thorough research of the process of acceptance of skateboarding activities in current urban park systems. This conclusion also indicates further areas for research with the purpose of understanding general best practices in urban parks sport space planning.

• Journal of Korean Ophthalmic Optics Society
• /
• v.17 no.4
• /
• pp.365-372
• /
• 2012

Purpose: To investigate ocular higher order aberrations (HOA) and spherical aberration changes caused by an aspheric soft contact lens designed to reduce spherical aberration (SA) of the eye. Methods: Fifty subjects who have successfully experienced soft contact lenses were refitted with aspheric design (Soflens Daily Disposable: SDD, Bausch+Lomb) soft contact lens. Ocular higher order aberrations (HOA) and stand alone SA were measured and analyzed for a 4-mm pupil size using Wave-Scan Wavefront$^{TM}$ aberrometer (VISX, Santa Clara, CA, USA). High and low contrast log MAR visual acuity and contrast sensitivity function (CSF) were also measured under photopic and mesopic conditions (OPTEC 6500 Vision Tester$^{(R)}$). All measurements were conducted monocularly with an undilated pupil. Results: The RMS mean values for total HOA with SDD contact lenses were significantly lower than those at with unaided eyes (p<0.001) and a reduction for SA in the SDD was close to the baseline SA (zero ${\mu}m$) (p<0.001). For the SDD lens, there was a statistically significant correlation between the changes in the total HOA and the contact lens power (r=0.237, p=0.018) as well as between the changes in SA and the lens power (r=0.324, p=0.001). High contrast visual acuity (HCVA) and low contrast visual acuity (LCVA) with SDD lenses were $-0.063{\pm}0.062$ and $0.119{\pm}0.060$, respectively under photopic and $-0.003{\pm}0.063$ and $0.198{\pm}0.067$, respectively under mesopic condition. Contrast Sensitivity Function (CSF) with SDD lenses under both photopic and mesopic conditions was $3.095{\pm}0.068$ and $3.087{\pm}0.074$, respectively. Conclusions: The SDD contact lens designed to control SA reduced the total ocular HOA and SA of the eye, resulting in compensating for positive SA of the eyes. Thus, the optical benefits of the lens with SA control would be adopted for improving the quality of vision.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.3
• /
• pp.254-259
• /
• 2001

In order to make clear the resistance of plane nettings u,sed widely in constructing net cages, the resistance R taken by $R=kSU^2$, where S was the wall area of nettings, U the flow velocity, and k the resistance coefficient, was measured in a circulating water channel by using nylon Raschel nettings and PE trawler-knotted nettings coated with anti-fouling paint or not and then the properties of coefficient k were investigated. The mesh size L and the angle $\phi$ between two adjacent bars was given by the function of Reynolds number ${\lambda}U/v$ in the region of ${\lambda}U/v<180$, i. e., $$k=350(\frac{\lambda U}{v})^{-0.25}$$.where $\lambda$ was the representative size of nettings expressed as $$\lambda=\frac{{\pi}d^2}{2L\;sin\;2{\phi}}$$On the other hand, the coefficient k was almost fixed between 92 and 102 ($kg{\cdot}s^2/m^4$) in the region of ${\lambda}U/v{\geq}180$ and varied according to the ratio $S_n/S$ of the total area $S_n$ of nettings projected to the plane perpendicular to the water flow to the wall area S of nettings, i.e., it was given by $$k=98.6(\frac{S_n}{S})^{1.19}$$ regardless of the coating of paint.