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Effect of Sanitation Treatment of Extending Shelf-life on Fresh Poultry Meats (계육(鷄肉)의 유통기간연장(流通期間延長)을 위(爲)한 위생처리방법(衛生處理方法)에 관(關)한 연구(硏究))

  • Cho, M.J.;Jang, P.H.;Park, K.B.;Lee, B.M.
    • Korean Journal of Food Science and Technology
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    • v.14 no.4
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    • pp.291-300
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    • 1982
  • In order to develop effective and simple sanitation method for the extention of shelf-life of fresh poultry meat, the effect of sanitizers, sanitation methods and packaging materials on the extention of shelf-life of poultry meats was observed at the $4^{\circ}C$ and room temp$(10{\sim}20^{\circ}C)$. The results are summarized as follows: 1. The autochonous skin microflora of poultry, before processing, were believed to be removed or killed during the scalding and plucking, and exposed dermal tissue was contaminated by microorganisms from the subsequent stages of processing. 2. In the final stage of poultry processing, total viable counts of microorganisms and coliforms were averaged to $3.5{\times}10^4/cm^2$ and $400/cm^2$, respectively. 3. The refrigerated shelf-life of fresh whole poultry carcasses at $3\;to\;4^{\circ}C$ was extended to 7 to 16 days compared to control with the various treatments of some sanitizers by dipping freshly chilled carcasses for 5 min or spraying 1 liter of sanitizers per carcasses. In the case of storage at $10\;to\;15^{\circ}C$, the shelf-life of poultry carcasses was extended to one to two days by the sanitation treatments compared to control. 4. Spraying sanitation was more effective than dipping sanitation, and 5 minutes dipping and one liter spraying per carcass were enough for effective sanitation of poultry carcasses in most sanitizers. 5. The packaging with an oxygen impermeable polyvinylidene chloride extended the shelf-life to 10 days and 5 days with polyethylene compared to control. When poultry carcasses were sanitized by continuous spraying with one liter of 30 ppm of chlorine and another one liter of 5% of potassium sorbate, packaged with polyvinylidene chlorlde were extended to about 30 days compared to control.

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The Change of The Effect on The Subcutaneous Fat Area and Visceral Fat Area by The Functional Electrical Stimulation and Aerobic Exercise (기능적 전기 자극과 유산소 운동이 복부비만의 피하지방과 내장지방에 미치는 효과)

  • Oh Sung-tae;Lee Mun-hwan;Park Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.16 no.1
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    • pp.85-123
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    • 2004
  • Back ground : Subcutaneous fat area is the main factor involved in replacement disease and arteriosclerosis. Simple weight control is the appropriate medical treatment. It's understood that weight reduction does not only reduce the fat concentrations in blood but also reduces blood pressure, improves glucose levels in diabetes patients and reduces incidents of heart disease. there are several methods for reducing fat in the abdominal region but their effectiveness is not folly understood. one method is electrical stimulation of the problem areas. Method : From May 1st 2002 to October 31st. The 15 subjects who received medical examination were aged between 25 and 53 and were of mixed gender. The subjects were divided into two groups one to received functional electrical stimulation and the other a control group. Using Broca's criterion for judging fat grades. I analysed the differences between the two groups before and after the treatment. Subjects received functional electrical stimulation on the abdominal muscle intensity 50Hz. They received this treatment 4 days a week for 40 minutes a day. In the case of aerobic exercise, at the Treadmill, we used it with the intensity of $75\%$ maximum heart rate (220-age). Result 1)After functional electrical stimulation in the case of male subjects, the weight was reduced 1.93kg, obesity $2.60\%$, fat mass 2.73kg, Percent body fat $4.40\%$, waist circumference 6.53cm, circumference of hips 5.53cm. On the other side, the quality of muscle was increased at the rate of 1.03kg, but it's not attentional level. The subcutaneous fat area was reduced by $26.63cm^2$, the visceral fat area was reduced by $43.00cm^2$, In the female subjects, we can see the reduction of fat grade by $26.63cm^2$, the quantity of body fat by 1.5kg, percent body fat by $1.77\%$, circumference of waist by 4.02cm, circumference of hips by 3.67cm, weight by 1.40kg but was increased 0.72kg at the quantity of muscles. We can see the reduction also in the subcutaneous fat area $24.03cm^2$, the visceral fat area by $25.36cm^2$. 2)After aerobic exercise, on the male subjects, we can see reduction of weight by 3.36kg, obesity by $4.00\%$, fat mass by 2.83kg and we can see increase at the soft lean mass by 2.96kg, but we can see reduction, the percent body fat by $3.03\%$, fat distribution by $0.023\%$, circumference of waist by 3.10cm, circumference of hips by 2.23cm. The female subjects show a reduction in the weight by 2.48kg, percent body fat by $2.20\%$, show an increase in the soft lean mass by 1.54kg. We can see a reduction in the quantity of fat mass by 2.32kg, the percent body fat by $2.80\%$, the circumference of waist by 2.16cm, the circumference of hips by 2.68cm, the fat distribution by $0.016\%$, the subcutaneous fat area by $15.25cm^2$ the visceral fat area by $11.52cm^2$. After aerobic exercise, we can't see the attentional change at the total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol. 3)After the application of functional electrical stimulation and aerobic exercise, in result of measurement on the body ingredient, we could see the weight reduction and increase the quantity of muscle with the male group who exercised aerobic. We can see the attentional rate on the electrical stimulation about abdominal fat rate, circumference of waist, circumference of hips. The other hand, I couldn't see the attentional differences between the two groups in the rate of fatness and quantity of body fat and the rate of body fat. There isn't any attentional difference in the area of fat under skin, on the contrary, There is attentional difference in the fat in the internal organs area at the electrical stimulation site. We can't see the attentional change of total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol between electrical stimulation and aerobic exercise. 4)After execution of functional electrical stimulation and aerobic exercise, in result of measurement on change of body ingredient among female objects, We could see weight reduction, increase at muscle quantity in the aerobic exercise group. We could see the attentional differences in the rate of fatness, the rate of abdominal region, the circumference which received electrical stimulation. But, we couldn't see the attentional differences between two groups in the quantity of body fatness, the circumference of hips. The subcutaneous fat area doesn't show the attentional differences. On the Contrary, we could see lots of differences in the visceral fat area of the electrical stimulation group. Conclusion The results show that functional electrical stimulation and aerobic exercise have insignificant differences when if comes to total cholesterol, triglyceride, high density lipoprotein cholesterol, low density lipoprotein cholesterol. Though there is affirmative change in body ingredient after both electrical stimulation and aerobic exercise. Functional electrical stimulation is more effective on the subcutaneous fat area and in changing visceral fat area. There fore. It is concluded that the physical therapy is more effective in the treatment of abdominal fatness.

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A study on the Relationship between the Degree of Awareness on Low Carbon Green Growth and the Organizational Commitment Focused on the Traditional Retailers (전통시장 상인들의 저탄소 녹색성장에 대한 인식과 조직몰입의 관계에 대한 연구)

  • Yang, Hoe-Chang;Kim, Sung-Il;Park, Young-Ho;Lee, Shang-Nam
    • Journal of Distribution Science
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    • v.9 no.3
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    • pp.37-46
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    • 2011
  • Since the Korean retail industry was made accessible to the big conglomerates and foreign retail companies, local traditional markets have faced serious problems. To sustain the local traditional markets' survival, the Korean government established various remedial policies for addressing, and many scholars published articles to suggest how to find solutions to, the problem. Unfortunately, the results have not been satisfactory. The purpose of this study is to find another way to help the Korean traditional retail market, from the view point of the Green Growth Policy, an initiative designed to address environmentally balanced economic growth in Korea. In order to survive and to maintain sustainable growth, it is incumbent upon retailers in the traditional market to understand the concept of the Green Growth Policy. A survey was conducted as a means of testing the degree of awareness of the Green Growth Policy, as well as determining the relationship between the degree of awareness and the degree of organizational commitment by the retailers in the local traditional markets. Interestingly, we were able to detect some of the features (e.g., they were distinguished by the elderly and the young, as well as low level of education and high level of education) in the traditional market retailers' demographic characteristics. We utilized the analysis of variance (ANOVA) statistical method to simultaneously compare the differences in retailers' demographic characteristics; the results were as follows: Overall, the results showed that the awareness of the Green Growth Policy, the degree of trust in the government's policy, levels of self-efficacy, and levels of organizational commitment were higher with the older traditional market retailers than the younger traditional market retailers. Specifically, the degree of trust in government policies (F=9.964,p < .05), levels of self-efficacy (F=5.532,p < .05), and levels of organizational commitment (F=5.697,p < .05) were statistically significant. Moreover, in the portion of the study that addressed the difference between education levels, all the variables were averaged in the higher education category of the traditional market retailers. Specifically, awareness levels of the Green Growth Policy (F=8.564,p < .005) and levels of self-efficacy (F=6.754,p < .005) were statistically significant. These results revealed that the traditional market retailers' demographic characteristics should be considered important factors in order to realize their policy. The results of the study showed the following: 1) The degree of awareness of the government's Green Growth Policy was statistically significant as it related to traditional market retailers' organizational commitment. 2) The degree of trust of the government's policy was significantly moderated between the awareness of the government's Green Growth Policy and the traditional market retailers' organizational commitment. This result demonstrates that the traditional market retailers' awareness of the government's Green Growth Policy will show more organizational commitment with higher levels of trust of the government's policy. 3) It also revealed that traditional market retailers' self-efficacy was fully mediated between the awareness of the Green Growth Policy of the government and traditional market retailers' organizational commitment. The results suggest that the government should show an interest in showing traditional market retailers how to enhance their traditional markets. Implications and future research directions are also discussed.

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Physico-chemical Properties of Soils Developed on the Different Topographies in Korea (우리나라 농경지토양(農耕地土壤)의 지형별(地形別) 이화학적(理化學的) 특성(特性))

  • Hyeon, Geun-Soo;Park, Chang-Seo;Jung, Sug-Jae;Moon, Joon
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.4
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    • pp.271-279
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    • 1989
  • Mean values representing the particle size distribution and some chemical properties for the cultivated soils were obtained from the analysis results of the typical profiles, which were described by the detailed soil maps throughout Korea. Analysis results of 5,215 soil samples (3,075 for paddy and 2,140 for upland) were available for the determination of mean values. The results are under. 1. Paddy topsoil contained 20.4% for clay, 5.8 for pH, 2.6% for organic matter, 10.4me/100g for exchangeable K, and 89ppm for available $P_2O_5$. Upland topsoil did 17.3% for clay, 5.5 for pH, 1.8% for organic matter, 9.lme/100g for CEC, 0.29me/100g for exchangeable K, and 103ppm for availabal $P_2O_5$. 2. Soil properies for paddy were markedly influenced by the reliefs. Topsoil contained 21.4% for clay, 6.0 for pH, 2.2% for organic matter, 10.8me/100g for CEC, 0.39me/100g for exchang-cable K and 57ppm for available $P_2O_5$ on the fluvio-marine plain, 15.3%, 5.7, 2.0%, 8.6me/100g, 0.17me/100g and 76ppm on the alluvial plain, 18.8%, 5.9, 2.7%, 10.4me/100g, 0.19me/100g and 80ppm on the valleys and fans, 25.0%, 5.7, 2.5%, 11.5me/100g, 0.26me/100g, 0.27me/100g and 141ppm on the moutain foot slopes, respectively. 3. Soil Properties for upland, also, were markedly influenced by the reliefs. Topsoil contained 5.5% for clay, 5.7 for pH, 1.1% for organic matter, 4.7me/100g for CEC, 0.17me/100g for exchangeable K and 50ppm for available $P_2O_5$ on the fluvio-marine plain, 10.3%, 5.5, 1.4%, 7.6me/100g, 0.26me/100g and 160ppm on the alluvial plain, 13.9%, 5.4, 1.8%, 9.3me/100g, 0.24me/100g and and 184ppm on the valleys and fans, 29.8%, 5.3, 2.1%, 11.2me/100g 0.40me/100g and 58ppm on the alluvial plain, 20.0%, 5.7, 2.7%, 11.4me/100g, 0.32me/100g and 116ppm on the mountain foot slopes, and 24.6%, 5.3, 1.8%, 10.2me/100g, 0.28me/100g and 51ppm on the rolling and Hill. 4. All chemical properties did not reach the ideal value for maximizing land capability. 5. Organic matter, exchangeable cations and available $P_2O_5$ were not normally distributed. Intervals of one and two standard deviations about mean of an approximately normal distribution were calculated.

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Residual Effects of Basic Oxygen Furnace Slag as Soil Conditioner in the Rice Paddy Field (논토양 벼 재배에서 제강슬래그의 토양개량제로서의 시용효과)

  • Lim, June-Taeg;Kim, Young-Sin;Park, Jn-Jin;Lee, Choong-Il;Hyun, Kyu-Hawn;Kwon, Byung-Sun;Kim, Hak-Jin
    • Korean Journal of Soil Science and Fertilizer
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    • v.33 no.3
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    • pp.205-211
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    • 2000
  • This study was conducted to evaluate the residual effects of basic oxygen furnace (BOF) slag applied in rice paddy fields as soil conditioner one year before. The experimental fields of Lim et al. (2000) located in Youjung and Nampyung were used for this purpose. Both variety (Oryza sativa L. cv. Dongjinbyeo) and cultural practices were the same as those in Lim et al. (2000). Soil chemical properties, plant height, number of tillers per plant, yield and yield components were observed. The temporal variation of treatment mean value in soil chemical properties appeared to be similar trends in both Youjung and Nampyung experimental fields. Soil pH and Ca content were still significantly higher than those in control treatment up to July of the second season, but decreased progressively as time passed. However, the effects lasted longer as slag rate became higher. BOF slag seems to have residual effects as a soil conditioner or Ca fertilizer in soil for two years. BOF slag rate of $4Mg\;ha^{-1}$ raised soil pH almost the same as lime rate of $2Mg\;ha^{-1}$. Content of $SiO_2$ in soil applied slag appeared to be higher compared with control. Fe and Mg content in soil with slag treatment was significantly higher than that of control in 1997, but it was almost the same level as that of control in 1998. In YouJung experimental field, rough rice yield of slag teatment became higher as slage rate incresed. Slag rate of $12Mg\;ha^{-1}$ showed the highest rough rice yield of $5,400kg\;ha^{-1}$ among treatment, which was 14% higher than that of control with $4,720kg\;ha^{-1}$. Slag rate of $12Mg\;ha^{-1}$ showed relatively higher plant height and higher number of tillers at the early growth stage compared with other treatments. In NamPyung experimental field, rough rice yield was the highest at the plot of lime rate $2Mg\;ha^{-1}$ and became higher as slag rate increased. There were no significant differences in rough rice yield between lime treatment and slag treatments. Slag rate of $12Mg\;ha^{-1}$ showed the highest rough rice yield of $7,170kg\;ha^{-1}$ among slag treatment, which was 8% significantly higher than that of control with $6,670kg\;ha^{-1}$. Slag rate of $12Mg\;ha^{-1}$ showed relatively slower growth in plant height at the early growth stage, but superior growth at the later growth stage, and significantly higher number of spiklets per panicle and 1000-grain weight than that of control.

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Converting Ieodo Ocean Research Station Wind Speed Observations to Reference Height Data for Real-Time Operational Use (이어도 해양과학기지 풍속 자료의 실시간 운용을 위한 기준 고도 변환 과정)

  • BYUN, DO-SEONG;KIM, HYOWON;LEE, JOOYOUNG;LEE, EUNIL;PARK, KYUNG-AE;WOO, HYE-JIN
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.23 no.4
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    • pp.153-178
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    • 2018
  • Most operational uses of wind speed data require measurements at, or estimates generated for, the reference height of 10 m above mean sea level (AMSL). On the Ieodo Ocean Research Station (IORS), wind speed is measured by instruments installed on the lighthouse tower of the roof deck at 42.3 m AMSL. This preliminary study indicates how these data can best be converted into synthetic 10 m wind speed data for operational uses via the Korea Hydrographic and Oceanographic Agency (KHOA) website. We tested three well-known conventional empirical neutral wind profile formulas (a power law (PL); a drag coefficient based logarithmic law (DCLL); and a roughness height based logarithmic law (RHLL)), and compared their results to those generated using a well-known, highly tested and validated logarithmic model (LMS) with a stability function (${\psi}_{\nu}$), to assess the potential use of each method for accurately synthesizing reference level wind speeds. From these experiments, we conclude that the reliable LMS technique and the RHLL technique are both useful for generating reference wind speed data from IORS observations, since these methods produced very similar results: comparisons between the RHLL and the LMS results showed relatively small bias values ($-0.001m\;s^{-1}$) and Root Mean Square Deviations (RMSD, $0.122m\;s^{-1}$). We also compared the synthetic wind speed data generated using each of the four neutral wind profile formulas under examination with Advanced SCATterometer (ASCAT) data. Comparisons revealed that the 'LMS without ${\psi}_{\nu}^{\prime}$ produced the best results, with only $0.191m\;s^{-1}$ of bias and $1.111m\;s^{-1}$ of RMSD. As well as comparing these four different approaches, we also explored potential refinements that could be applied within or through each approach. Firstly, we tested the effect of tidal variations in sea level height on wind speed calculations, through comparison of results generated with and without the adjustment of sea level heights for tidal effects. Tidal adjustment of the sea levels used in reference wind speed calculations resulted in remarkably small bias (<$0.0001m\;s^{-1}$) and RMSD (<$0.012m\;s^{-1}$) values when compared to calculations performed without adjustment, indicating that this tidal effect can be ignored for the purposes of IORS reference wind speed estimates. We also estimated surface roughness heights ($z_0$) based on RHLL and LMS calculations in order to explore the best parameterization of this factor, with results leading to our recommendation of a new $z_0$ parameterization derived from observed wind speed data. Lastly, we suggest the necessity of including a suitable, experimentally derived, surface drag coefficient and $z_0$ formulas within conventional wind profile formulas for situations characterized by strong wind (${\geq}33m\;s^{-1}$) conditions, since without this inclusion the wind adjustment approaches used in this study are only optimal for wind speeds ${\leq}25m\;s^{-1}$.

Dismantling and Restoration of the Celadon Stool Treasure with an Openwork Ring Design (보물 청자 투각고리문 의자의 해체 및 복원)

  • KWON, Ohyoung;LEE, Sunmyung;LEE, Jangjon;PARK, Younghwan
    • Korean Journal of Heritage: History & Science
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    • v.55 no.2
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    • pp.200-211
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    • 2022
  • The celadon stools with an openwork ring design which consist of four items as one collection were excavated from Gaeseong, Gyeonggi-do Province. The celadon stools were designated and managed as treasures due to their high arthistorical value in the form of demonstrating the excellence of celadon manufacturing techniques and the fanciful lifestyles during the Goryeo Dynasty. However, one of the items, which appeared to have been repaired and restored in the past, suffered a decline in aesthetic value due to the aging of the treatment materials and the lack of skill on the part of the conservator, raising the need for re-treatment as a result of structural instability. An examination of the conservation condition prior to conservation treatment found structural vulnerabilities because physical damage had been artificially inflicted throughout the area that was rendered defective at the time of manufacturing. The bonded surfaces for the cracked areas and detached fragments did not fit, and these areas and fragments had deteriorated because the adhesive trickled down onto the celadon surface or secondary contaminants, such as dust, were on the adhesive surface. The study identified the position, scope, and conditions of the bonded areas at the cracks UV rays and microscopy in order to investigate the condition of repair and restoration. By conducting Fourier-transform infrared spectroscopy(FT-IR) and portable x-ray fluorescence spectroscopy on the materials used for the former conservation treatment, the study confirmed the use of cellulose resins and epoxy resins as adhesives. Furthermore, the analysis revealed the addition of gypsum(CaSO4·2H2O) and bone meal(Ca10 (PO4)6(OH)2) to the adhesive to increase the bonding strength of some of the bonded areas that sustained force. Based on the results of the investigation, the conservation treatment for the artifact would focus on completely dismantling the existing bonded areas and then consolidating vulnerable areas through bonding and restoration. After removing and dismantling the prior adhesive used, the celadon stool was separated into 6 large fragments including the top and bottom, the curved legs, and some of the ring design. After dismantling, the remaining adhesive and contaminants were chemically and physically removed, and a steam cleaner was used to clean the fractured surfaces to increase the bonding efficacy of the re-bonding. The bonding of the artifact involved applying the adhesive differently depending on the bonding area and size. The cyanoacrylate resin Loctite 401 was used on the bonding area that held the positions of the fragments, while the acrylic resin Paraloid B-72 20%(in xylene) was treated on cross sections for reversibility in the areas that provided structural stability before bonding the fragments using the epoxy resin Epo-tek 301-2. For areas that would sustain force, as in the top and bottom, kaolin was added to Epo-tek 301-2 in order to reinforce the bonding strength. For the missing parts of the ring design where a continuous pattern could be assumed, a frame was made using SN-sheets, and the ring design was then modeled and restored by connecting the damaged cross section with Wood epos. Other restoration areas that occurred during bonding were treated by being filled with Wood epos for aesthetic and structural stabilization. Restored and filled areas were color-matched to avoid the feeling of disharmony from differences of texture in case of exhibitions in the future. The investigation and treatment process involving a variety of scientific technology was systematically documented so as to be utilized as basic data for the conservation and maintenance.

Gonadal Maturation and Spawning of River Puffer Takifugu obscurus Indoor Cultured in Low Salinity (저염분에서 사육한 황복 Takifugu obscurus 생식소의 성숙과 산란)

  • Kang, Hee-Woong;Chung, Ee-Yung;Kang, Duk-Young;Park, Young-Je;Jo, Ki-Che;Kim, Gyu-Hee
    • Journal of Aquaculture
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    • v.21 no.4
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    • pp.331-338
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    • 2008
  • Monthly changes in the gonadosomatic index (GSI) and hepatosomatic index (HSI) of wild river puffer Takifugu obscurus, and water quality environment in spawning area during breeding season were investigated from March 1995 to February 1996. Monthly changes in GSI and HSI of T. obscurus, that was cultured in low salinity, were calculated. The external morphology of the gonads, germ cell differentiation during gametogenesis and the reproductive cycle with the gonad developmental phases were investigated by histological analysis. The optimum water quality environment in Ganggyung, Choongcheongnam-do, where is spawning ground of wild T. obscurus, was $15-20^{\circ}C$ (water temperature) and 0 psu (salinity). Monthly changes in the GSI in females and males reached a maximum in May, and then rapidly decreased. Therefore, it is assumed that in the natural condition the spawning period of wild T. obscurus is May to June. In females and males, it showed a negative correlationship between the GSI and HSI. The external morphology of the gonads in female and male T. obscurus, that was cultured in low salinity, is composed of a pair of saccular structure. Based on monthly changes in the GSI, it is assumed that in female T. obscurus, that was cultured in low salinity, spawn from March through May. Therefore, it showed a negative correlationship between changes in the GSI and HSI. On the whole, in females and males, it showed a similar pattern between wild and cultured T. obscurus. The reproductive cycle with the gonad developmental phases can be classified into successive five stages in females: the early growing stage, late growing stage, mature stage, ripe and spent stage, and recovery and resting stage. In males, that can be divided into successive four stages: the growing stage, mature stage, ripe and spent stage, and recovery and resting stage. In case of wild T. obscurus, the spawning period has once a year, however, those cultured in the high water temperature ($20-27^{\circ}C$) - low salinity (under 3.3 psu) condition have reproductive characteristics having possibilities of discharge of eggs and sperms year-round as a multiple spawner.

Optimum Dietary Lipid Level and Feeding Rates of Extruded Pellets in Juvenile Flounder Paralichthys olivaceus during the Summer Season (여름철 넙치치어 배합사료의 적정지질함량 및 공급량)

  • Choi, Se-Min;Kim, Kang-Woong;Kang, Yong-Jin;Park, Hung-Sik;Bai, Sung-Chul C.
    • Journal of Aquaculture
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    • v.21 no.4
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    • pp.244-251
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    • 2008
  • We evaluated the optimum dietary lipid level and feeding rates of extruded pellets (EP) in juvenile flounder Paralichthys olivaceus during the summer season. The first experiment was conducted to determine the optimum dietary lipid level in juvenile flounder. Five isonitrogenous EP (52% crude protein) with increasing dietary lipids (6, 8, 10, 12 and 14%) were fed to satiety to triplicate groups of the juveniles ($18.4{\pm}0.11g$) twice a day for 6 weeks. Weight gain (WG) of fish fed EP with 10% lipid was significantly higher than those of fish fed EP with 6 and 14% lipid (P<0.05). Broken line model analysis suggested that the optimum dietary lipid level could be $9.08{\pm}0.37%$ for the maximum WG in juvenile flounder. The second experiment was conducted to determine the optimum feeding rate using experimental diet contained 10% lipid level that had the highest WG in first experiment. The feed intake of triplicate groups of the juveniles ($13.4{\pm}0.15g$) was restricted to four different feeding rates of 2.0, 2.5, 3.0 and 3.5% of their body weight $day^{-1}$ and to satiation using experimental diets. WG and feed efficiency (FE) of fish was affected by feeding rates. WG and specific growth rate of fish fed the diets increased with increasing feeding rate, however no significant differences (P>0.05) in WG and specific growth rate were observed between the fish fed 3.5% of their body weight $day^{-1}$ and to satiation. FE of fish fed 3.5% of their body weight $day^{-1}$ was significantly higher than those offish fed 2.0% of their body weight $day^{-1}$ and to satiation (P<0.05). Broken line model analysis suggested that the optimum dietary feeding rate could be $3.56{\pm}0.06%$ for the maximum WG in juvenile flounder. These results indicated that the optimum lipid level and feeding rate could be $9{\sim}10%$ (Energy: 4,774kcal and PIE ratio: 108mg protein/kcal in diet) and 3.5% of their body weight $day^{-1}$in juvenile flounder, respectively.

A Study on the Heavy Metals Concentrations in the Air of the Dental Laboratories, in the Blood and Urine of Dental Laboratory Technicians (치과기공실 공기중 및 치과기공사의 혈액, 요중 중금속 함량에 관한 연구)

  • Cha, Sung-Soo
    • Journal of Technologic Dentistry
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    • v.10 no.1
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    • pp.11-24
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    • 1988
  • The purpose of this study was to determine the concentration of cadmium, nickel and chromium in the air of the work-place, blood of and urine of workers and compare the level of those heavy metals by the duration of work, work-place, process of work, smoking and other factors. In this study, 48 male dental laboratory technicans and 72 office workers as the control group were subjected. The concentration of cadmium, nickel and chromium in their blood sand urine, and that of heavy metals in the air of their work-rooms were examined and analyzed from June I 1987 to September 30, 1987. The results were as follows : 1. The concentration of cadmium in the air was the highest in the porcelain part, $0.0087{\pm}0.0016mg/m^3$, that of nickel was the highest in the crown bridge part, $0.4253{\pm}0.0052mg/m^3$, and that of chrnmium was highest in the partial denture part, $0.1063{\pm}0.0024mg/m^3$. 2. cadmium, nickel and chromium concentrations in the blood and urine of dental laboratory techincians were higher that in the office workers'. Especially the concentration of cadmium in the blood($1.92{\pm}1.23{\mu}g$/100ml) of th dental laboratory techician was about two times as high as that in the office workers'($0.90{\pm}0.73{\mu}g$/100ml), and the concentration of nickel in the urine($48.53{\pm}38.83{\mu}g$/e) of the dental laboratory thchnician was about two times as high as that in the office worker's($20.24{\pm}15.35{\mu}g$/e). 3. there was no difference in the concentration of cadmium, nickel and chromium in the blood and urine with a longer duration of work. 4. The concentration of cadmium and chromium in the blood and urine differed significantly depending upon the place of work. The concentration of cadmium was the highest in the blood of dental laboratory technicians working kin the poreclain part marking at $2.53{\pm}1.08{\mu}g$/100ml. The chromium level was the heighest in the blood of partial denture park workers with a concentration of $3.60{\pm}1.02{\mu}g$/100ml. Concerning the level of cadmium in urine, it was the highest in the porcelain part workers with a concentration of $3.41{\pm}3.15{\mu}g$/e. 5. The concentration of cadmium in the urine of metal trimming and polishing group($2.64{\pm}2.41{\mu}g$/e) was higher than that of non-metal trimming and polishing group($1.39{\pm}1.18{\mu}g$/e). 6. The concentration of chromium in the blood of smoking group($2.46{\pm}1.54{\mu}g$/100ml)was higher than that lf non-smoking group($1.54{\pm}1.25{\mu}g$/100ml). 7. The height positive correlation coefficient was shown between the concentration of nickel and chromium in the blood among the all correlations between 3metals(Cd, Ni, Cr) in the blood and those in urine. The correlation coefficient was relatively high(r=0.605,,p<0.01). In general, the higher the concentration of heavy metals in the air of work places the higher the concention lf them in the blood and urine of workers, mere attention should be paid to the working environment of dental laboratory workers, Furthermore, continuous biological monitoring and further research are required for an efficient health management for dental laboratory workers.

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