• Journal of the Korea Concrete Institute
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• v.14 no.1
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• pp.126-135
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• 2002

Plate bonding technique has been widely used in strengthening of existing concrete structures, although it has often a serious problem of premature falure such as interface separation and rip-off. However, this premature failure problem has not been well explored yet especially in view of local failure mechanism around the interface of plate ends. The purpose of the present study is, therefore, to identify the local failure of strengthened plates and to derive a separation criterion at the interface of plates. To this end, a comprehensive experimental program has been set up. The double lap pull-out tests considering pure shear force and half beam tests considering combined flexure-shear force were performed. The main experimental parameters include plate thickness, adhesive thickness, and plate end arrangement. The strains along the longitudinal direction of steel plates have been measured and the shear stress were calculated from those measures strains. The effects of plate thickness, bonded length, and plate end treatment have been also clarified from the present test results. Nonlinear finite element analysis has been performed and compared with test results. The Interface properties are also modeled to present the separation failure behavior of strengthened members. The cracking patterns as well as maximum failure loads agree well with test data. The relation between maximum shear and normal stresses at the interface has been derived to propose a separation failure criterion of strengthened members. The present study allows more realistic analysis and design of externally strengthened flexural member with steel plates.

• Korean Journal of Poultry Science
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• v.25 no.4
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• pp.169-175
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• 1998

A feeding trial was carried out to evaluate optimum feeding system to Korean Native Chicken (KNC) with various feeding programs for 64 weeks. Eight hundreds and ten KNC＇one day birds were assigned to three feeding systems, NRC(T1), Japanese Feeding Standard(T2), Korean Feeding Standard(T3). Each treatment had three replicates of 90 birds a replicate. Data were obtained growing performance to 20 week of age and laying performance from twenty one to sixty four week. Viability to 20 week of age was similar to treatments. Growth characteristics by feeding systems were not significantly difference on body weight, feed intake and 50％ egg production days. However, body weight was less about 100g in T2. There were no different on egg production, egg weight, and egg mass during laying period. Feed intake of T1 was 104g daily and showed lower than other treatments, but was not different significantly. Feed conversion was significantly improved in T2(P <0.05) compared to other treatments(P<0.05). Egg production of all treatments was the highest between 27 to 30 week of age. ME intake of T1 was significantly maximized, whereas CP intake was the lowest of all treatments(P < 0.05). Nutrient requirements for egg mass tended to depend on nutrients intake. Interior egg and eggshell characteristics were not different among treatments except yolk color. Fertility and hatchability were similar to treatments, and the results at 39 week of age were higher than at 62 week in all treatments. In conclusion, treatments fed three or four phase feeding would be superior to other treatments during the growing period and suggest 2,800 ㎉/kg ME, 15％ CP for Korean native laying hen.

• Korean Journal of Poultry Science
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• v.32 no.4
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• pp.231-237
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• 2005

This study was carried out to evaluate the breeding values for economic traits in Korean native chicken on the basis of 11,583 birds of record along 7 generations collected from 1995 to 2001 at National Livestock Research Institute, Korea. The results obtained are summarized as follows : The breeding value estimates of the body weights at 150 and 270 days in Dark Brown, Light Brown, Gray Brown, Black and White strains were $-16.563\~0.474\;and\;-18.836\~21.700,\;-14.714\~9.272\;and\;-23.025\~11.297,\; -25.186\~12.953\;and\;-28.368\~18.156,\;-15.549\~6.329\;and\;-18.264\~4.963,\;-10.708\~20.284\; and\;-25.112\~10.132g$, respectively. The breeding value estimates of the ages at first egg in Dark Brown, Light Brown, Gray Brown, Black and White strains were $-1.236\~0.047,\;-1.509\~0.298,\;-1.362\~0.114,\;-1.436\~0.199\;and\;-1.385\~0.718$, respectively. The breeding value estimates of the egg weight at first egg and at 270 days were $-0.105\~0.075\;and\;-0.120\~0.398,\;-0.109\~0.042\;and\;-0.205\~0.173,\;-0.166\~0.084\;and\;-0.256\~0.091,\;-0.119\~0.066\;and\;-0.051\~0.132,\;-0.112\~0.027\;and\;-0.070\~0.101g$, respectively. The breeding value estimates of the egg Production to 270 days in Dark Brown, Light Brown, Gray Brown, Black and White strains were $0.298\~l.807,\;-0.049\~l.146,\;-0.396\~l.125,\;-1.206\~l.173\;and\;-0.474\~2.641$, respectively.

• The Journal of Korean Physical Therapy
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• v.3 no.1
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• pp.109-121
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• 1991

To investigate the period prevalence rate and therapeutic practic for low back pain (LBP) in the adult population of rural area, a personal interview was conducted for 2.024 persons or 20-59 years old in Seohu Myon, Andong County, Kyungpook Province between 1st and 20th of April, 1991. The period prevalence rate (l February 1990-31 January 1991) of LBP for 1,106 adults who were interviewed was $47.9\%$. The age adjusted period prevalence rate for males was $43.7\%$ and that for females was $52.3\%$ and the difference was statistically significant (p<0.005). Clinical course of th LBP was acute in $14.1\%$ of males and $9.0\%$ of females, recurrent in $57.0\%$ and $55.2\%$, and chronic in $28.9\%$ and $35.8\%$, respectively. Common causes of the LBP were insidious on set with aging without known cause$(48.1\%)$, heavy work $(15.1\%)$, and trauma $(11.3\%)$. Due to LBP $12.5\%$ of the patients were not able to stand or walk for more than an hour and $2.5\%$ were bed-ridden or unable to carry out daily routine. To have the LBP diagnosed $10.2\%$ of the patients utilized a oriental medical clinic or hospital, $31.3\%$ visited a clinic or hospital, and $56.6\%$ hat not utilized any medical facility. Main reason for not having the LBP diagnosed was that the LBP was tolerable. The most popular therapeutic method that the LBP patients chose at the first was drug and physical therapy. Herb medicine was most commonly used when the first therapeutic method was not effective and the acupuncture was the most popular choice of therapy when the second therapeutic method failed. Folk medicine was utilized in $15.5\%$ of the LBP patients and it included 36 regimens such as tincture of motherwort (Leonurus sibiricus), boiled chicken with liquor, etc. It was revealed by this survey that the LBP is a serious health problem in the rural area and many of the LBP patients do not utilize a clinic or hospital but take non-scientific folk remedy. To prevent the economic waste and side effects of the folk remedy, public health education is needed for tile rational therapy of LBP.

• Korean Journal of Veterinary Research
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• v.33 no.4
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• pp.649-655
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• 1993

A series of experiments on the effects of ${\gamma}-irradiation$ was performed to reveal the pathogenicity of ${\gamma}-irradiated$ oocysts of E tenella from Cobalt-60 and its progeny. The SPF chickens were inoculated with differnt doses of radiation and inoculum. The level of 100 Gy ${\gamma}-irradiation$ from $^{60}Co$ and the level of inoculum with $1{\times}10^4$ oocysts were recognized more pathogenic than those of the other groups by comparison of body weight gains, blood in feces and lesion scores. The signs of blood in feces, lesion score and the number of excreted oocysts in the feces were revealed as the lowest in the group of the ${\gamma}-irradiated$ oocysts, the average in the group of the 1st and the 3rd progeny, and the highest in the group of non-irradiated oocysts of E $tenell\grave{a}$. The body weight gain of the group immunized with ${\gamma}-irradiated$ oocysts of E tenella was higher than those of the non-irradiated, the 1st and 3rd progeny groups. The body weight gain of the groups immunized with the 1st and the 3rd progeny of E tenella were higher than that of the non-irradiated group. The feed conversion ration of the group immunized with ${\gamma}-irradiated$ oocysts of E tenella was lower than those of the non-irradiated, the 1st and the 3rd progeny groups. The feed conversion ratios of the group immunized with the 1st and 3rd progeny of ${\gamma}-irradiated$ oocysts were lower than that of the group infected with non-irradiated E tenella. The anticoccidial index(ACI 190.6) in the chickens immunized with the ${\gamma}-irradiated$ oocysts of E tenella and those(ACI 142.8 and 107.4) of the 1st and the 3rd progeny groups were higher than that (ACT 87.4) of the group infected with non-irradiated E tenella. It was thought that the pathogenicity of ${\gamma}-irradiated$ E tenella would be recovered according to increase the number of generation passaged in chicken.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.59-69
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• 2013

This study investigated the frequency, amount and consumption patterns of 50 potentially hazardous foods (PHF) along with consumers' risk perceptions towards PHF in Korea. A quantitative survey was performed from May through August by trained interviewers, surveying 1,000 adults aged over 18 who were randomly selected from six major provinces in Korea. Consumers perceived seafood, including shellfish, mussel, sashimi and sushi, as the top foods with the highest risk, followed by raw sliced beef. The food with the highest frequency intake per month was leafy vegetables, which is used to wrap other foods, followed by blanched vegetables, fried chicken, etc. The group of middle aged individuals with economic stability had the highest frequency intake of sashimi and sushi. Respondents living in small regions consume greater PHF portions at once. Food safety education with regard to the risk of PHF is essential for consumers, with high frequent intake of PHF.

• Journal of Food Hygiene and Safety
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• v.29 no.2
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• pp.158-163
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• 2014

In this study, two commercial PCR and ELISA test kits were examined for identification of eight animal species (beef, pork, chicken, duck, turkey, goat, lamb, and horse) from raw meat and meat products in Korea. The detection limit in RAW meat ELISA kit$^{(R)}$ on three types of meat samples blended with beef, pork and chicken, demonstrated that all meat species were differentiable down to 0.2%. RAW meat ELISA kit$^{(R)}$ on animal species resulted in differentiation rate of 94.5% for beef, 93.3% for pork, 90% for lamb, and 100% for chicken, duck, turkey, goat, and horse. In contrast, Powercheck Animal Species ID PCR kit$^{TM}$ resulted in 100% specificity at 0.05% limit of detection for all meat species. The detection limit of Cooked Meat ELISA kit$^{(R)}$ on mixed meat samples heat-treated with different temperatures and times, resulted in 0.1% for all heat-treated mixed meat except for chicken at 1.0%. Additionally, ELISA kit on sixty meat products resulted in specificity of 31.8% for ham, 13.6% for sausages, and 12.5% for ground processed products, and relatively low rate for more than 2 types of mixed meats. On the contrary, meat species differentiation using PCR kit showed higher percentage than that using ELISA kit$^{(R)}$: 50.0% for ham, 41.7% for sausages, and 28.6% for ground processed meat. Futhermore, PCR kit on 54 dried beef meats detected pork genes in 13 products whereas ELISA kit showed negative results for all products. Hence, the possibility of cross-contamination during manufacturing process was investigated, and it was found that identical tumblers, straining trays, cutters and dryers were used in both beef and pork jerky production line, suggesting the inclusion of pork genes in beef products due to cross-contamination. In this study, PCR and ELISA test kits were found to be excellent methods for meat species differentiation in raw meat and heat-processed mixed meat. However, lower differentiation rate demonstrated in case of meat processed products raised the possibility of inclusion of other species due to cross-contamination during manufacturing process.

• Journal of Food Hygiene and Safety
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• v.29 no.4
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• pp.340-346
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• 2014

In this study, the detection method was developed using real-time PCR to distinguish 4 species (bovine, porcine, horse, and chicken) of raw meats. The genes for distinction of species about meats targeted at 12S rRNA and 16S rRNA parts in mitochondrial DNA. Probes were designed to have a 5' FAM and a TAMRA at the 3' end. This study is to develop 4 species-specific primer and probes about raw materials and real-time PCR on 10 strains to observe the products of non-specific signal for similar species. As a result, any non-specific signal were not detected among each other. Real-time PCR method was developed for quantitation and identification of intentional and unintentional mixture in ground mixed meat (The difference of $C_T$ value between intentional mixture and 100% meat: $${\leq_-}$$ cycles, The difference of $C_T$ value between unintentional mixture and 100% meat: $${\geq_-}$$ cycles). The detection and differentiation of intentional and unintentional mixture in this study would be applied to food safety management for eradication of adulterated food distribution and protection of consumer's right.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.480-485
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• 2008

In this experiment, 5 treatments consisted of control, probiotics (0.2%; T1), illite (1.0%; T2), activated carbon (1.0%; T3), and hardwood vinegar (1.0%; T4) as diets of chicken were evaluated for 35 days through feeding of 200 male chickens (Arbor Acre Broiler). Thigh muscle from slaughtered chickens were analyzed on pH, volatile basic nitrogen (VBN), thiobarbituric acid reactive substance (TBARS), shear force, and meat color during 10 d of cold storage at $4{\pm}1^{\circ}C$. Groups of T3 and T4 showed higher pH levels compared to the control group, and T4 showed significantly higher value. Over the storage period, all treatment groups showed increase in pH (p<0.05). Values of VBN of T1, T3, and T4 were lower than those of the control group and T2 up to 7 d of storage (p<0.05), but there was no significance at 10 d of storage. Values of TBARS of T3 and T4 were lower than the control group, T1, and T2, while all treated groups showed rapid increase of TBARS values over storage period (p<0.05). Shear force did not show significant difference among treated groups, but it was decreased over storage. Lightness of meat color (L) in treated groups was higher than the control, and T4 showed the highest value during entire storage period (p<0.05). Yellowness levels (b) of T3 and T4 were higher than the control group. These results may suggest the improvement of chicken meat quality and shelf life via the addition 1% activated carbon and 1% hardwood vinegar into feed.

• Food Science of Animal Resources
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• v.28 no.4
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• pp.505-511
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• 2008

The goal of this study was to investigate the effects of dietary mugwort on the proximate composition, volatile basic nitrogen (VBN), thiobarbituric acid reactive substance (TBARS) and fatty acid in chicken meats. One hundred sixty broiler chicks (1 d old) were assigned to one or four dietary groups: Control; commercial feed supplemented with 1% mugwort (T1); commercial feed with 3% mugwort (T2) and commercial feed with 5% mugwort (T3). After 42 d, broilers from each group were slaughtered and meat samples were vacuum packaged and stored at $4{\pm}1^{\circ}C$ over a period of 0, 1,2,3, and 4 wk. Chicken breast was not influenced by all treatments in moisture, crude protein and crude fiber, while crude fat was lowered (p<0.05) in chickens fed with the T2 and T3 diets compared to the control and T1 diets. All treatments with mugwort diets tended to have decreased VBN values for chicken breast and thigh compared to control. As storage time increased, VBN was increased for all chickens (p<0.05). No significant differences in TBARS were observed among all treatments at 0 wk. TBARS values were reduced with the T2 and T3 diets and initially increased from 0 through 3 wk, then abruptly decreased at 4 wk. Dietary mugwort supplementation resulted in increased stearic acid (excepted T2) and oleic acid and decreased linoleic acid. Stearic acid in thigh meat was decreased in the T1, T2 and T3, however linoleic acid levels tended to increase with mugwort powder supplementation. It is concluded that dietary mugwort has a positive effect on increasing unsaturated fatty acid contents and decreasing saturated fatty acids.