• Title/Summary/Keyword: 실행연구

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Limitation of Nitrogen ion Implantation and Ionplating Techniques Applied for Improvement of Wear Resistance of Metallic Implant Materials (금속 임플란트 소재의 내마모성 향상을 위하여 적용되는 질소 이온주입 및 이온도금법의 한계)

  • 김철생
    • Journal of Biomedical Engineering Research
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    • v.25 no.2
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    • pp.157-163
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    • 2004
  • Nitrogen ion implantation and ion plating techniques were applied for improvement of the wear resistance of metallic implant materials. In this work, the wear dissolution behaviour of a nitrogen ion implanted super stainless steel (S.S.S, 22Cr-20Ni-6Mo-0.25N) was compared with those of S.S.S, 316L SS and TiN coated 316L SS. The amounts of Cr and Ni ions worn-out from the specimens were Investigated using an electrothermal atomic absorption spectrometry. Furthermore, the Ti(Grade 2) disks were coated with TiN, ZrN and TiCN by use of low temperature arc vapor deposition and the wear resistance of the coating layers was compared with that of titanium. The chemical compositions of the nitrogen ion implanted and nitride coated layers were examined with a scanting auger electron spectroscopy. It wat observed that the metal ions released from the nitrogen ion implanted S.S.S surface were significantly reduced. From the results obtained, it was shown that the nitrogen ion implanted zone obtained with 100 KeV ion energy was easily removed within 200,000 revolutions from a wear dissolution testing under a similar load condition when applied to artificial hip joint. The remarkable improvement in wear resistance weir confirmed by the nitrides coated Ti materials and the wear properties differ greatly according to the chemical composition of the coating layers. for specimens with the same coating thickness of about 3$\mu\textrm{m}$, TiCN coated Ti showed the highest wear resistance. However, after removing the coating layers, the wear rates of all nitrides coated Ti reverted to their normal rates of below 10,000 revolutions from Ti-disk-on-disk wear testing under the same load condition. From the results obtained, it is suggested that the insufficient depth of the 100 Kel N$\^$+/ ion implanted zone and of the nitrides coated layers of 3$\mu\textrm{m}$ are subject to restriction when used as frictional parts of load bearing implants.

Effects of Feeding Softwood By-products or Extract on Growth Performance, Intestinal Organs and Cecal Microbes in Organic Broiler Chicks (유기 육계에 침엽수 부산물과 추출물의 급여가 성장, 장기 및 맹장내 미생물에 미치는 영향)

  • Choe, H.S.;Part, J.H.
    • Korean Journal of Poultry Science
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    • v.34 no.1
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    • pp.15-21
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    • 2007
  • This study was conducted to evaluate the effects of dietary softwood by-products extract on growth performance, organ weight and intestinal microbes in organic broiler chicks. Five treatments were assigned to 200 broiler chicks with four replication, allocating 10 broiler chicks in each replication. Dietary treatments included control(Organic diet), +C(Organic diet + antibiotics), T1(Organic diet + softwood by-product powder 3.0%), T2(Organic diet + softwood by-product extract 0.05%) and T3(Organic diet + softwood by-product extract 0.1%). Body weight gain was higher in +C and T3 for overall period than control and T1. Feed efficiency of were slightly improved in +C and T3 groups compared with that of control and T1. The small intestine weight tended to be higher in control and +C, but it's length showed high in only T1 group. Gizzard weight was significantly higher in T2 compared with other treatments(P<0.05). In contrast, spleen weight was significantly lower in control group(P<0.05), whereas the weight of cecum and liver were not significantly different by dietary treatment. Intestinal microflora was significantly lower or/and seemed to be low in softwood by-products treatment groups than control. Digestibility of energy and protein were statistically lower in control and T1 than other treatments(P<0.05). The IgG concentration of birds fed antibiotics, softwood by-product extract was higher than control and T1, but was no significance. The results of this experiments indicated that softwood by-product extract would be possible to apply for the feed additive in organic broiler diets.

Overview of Real-time Visibility System for Food (Livestock Products) Transportation Systems on HACCP Application and Systematization (축산물 유통단계의 HACCP 적용과 체계화를 위한 실시간 관제시스템에 대한 현황)

  • Kim, Hyoun-Wook;Lee, Joo-Yeon;Hong, Wan-Soo;Hwang, Sun-Min;Lee, Victor;Rhim, Seong-Ryul;Paik, Hyun-Dong
    • Food Science of Animal Resources
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    • v.30 no.6
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    • pp.896-904
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    • 2010
  • HACCP is a scientific and systematic program that identifies specific hazards and gives measurements in order to control them and ensure the safety of foods. Transportation of livestock and its products is one of the vulnerable sectors regarding food safety in Korea, as meats are transported by truck in the form of a carcass or packaged meat in a box. HACCP application and its acceleration of distribution, in particular transportation, are regarded as important to providing consumers with ultimately safe livestock products. To achieve this goal, practical tools for HACCP application should be developed. Supply chain management (SCM) is a holistic and strategic approach to demand, operations, procurement, and logistics process management. SCM has been beneficially applied to several industries, notably in vehicle manufacture and the retail trade. HACCP-based real-time visibility system using wireless application (WAP) of the livestock distribution is centralized management system that enables control of temperature and HACCP management in real-time for livestock transportation. Therefore, the application of HACCP to livestock distribution (transportation, storage, and sale) can be activated. Using this system, HACCP management can be made easier, and distribution of safe livestock products can be achieved.

Studies on Dairy Farming Status, Reproductive Efficiencies and Disorders in New Zealand (II) A Survey on Reproductive Efficiencies and Disorders in Palmerston North Area (뉴질랜드 (Palmerston North) 의 낙농 현황과 번식 및 번식장해에 관한 연구 (II) Palmerston North 지역의 낙농 번식현 황과 번식장해에 관한 조사)

  • 김중계;맥도날드
    • Korean Journal of Animal Reproduction
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    • v.24 no.1
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    • pp.19-33
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    • 2000
  • Eighty dairy farms (38 farms responded) in Palmerston North area of New Zealand were questioned by mail questionnaire on: 1) general characteristics, 2) milk yield and feed supplementary, 3) reproductive efficiencies (12 questions) and 4) reproductive disorders (12 questions) from February to July, 1998. Among those 4 items, the reproductive efficiencies (3) and disorders (4), various diseases and culling rates were surveyed and analyzed for Korean dairy farmers (especially in Cheju island) and compared with New Zealand. The results are as follows: 1. Fifteen farms in 38 dairy farms relied entirely on artificial insemination, the rest of 23 dairy farms (60.5%) raised 5∼6 bulls to increase conception rate. The dairy farmers in Palmerston North used artificial insemination from Oct 4th to Dec 10th for 42.8 days, and then used bulls from that point to coming Jan 10th for 41.4 days. The submission rate within 3, 6 and 10 weeks following the initiation of AI season was 84.7, 93.9 and 97.9% respectively. 2. The average age of heifers at the first estrus, pregnancy and calving was 11.0, 18.0 and 24.7 months respectively, and an average 1.4 estrus cycles were required for conception. The intervals of estrus recurrence and the following conception after calving were 38 and 68 days respectively. 3. Among inseminated cows, calving, abortion and empty cow was 90.9, 1.6 and 7.4% respectively. Calving rate decreased according to increasing farm size, while the number of empty cows decreased. 4. Stillbirth, retained placenta and delivery abnormalities were 5.3, 3.7 and 5.5% respectively, not different depend on herd size. 5. The incidence of milk fever, grass tetany, and ketosis was 3.6, 3.0 and 1.0%, respectively. The delivery abnormality and mastitis treated with medicine were 3.1 and 6.7%, but decreased according to farm size. Lameness was 8.6% on average, but over 10% in farms which has more than 400 milking cows. 6. Among the culled cows (15.5% of the total), those culled due to an old age, lameness and other diseases were 2.9, 1.8 and 4.3% respectively and those culled due to low milk production, reproductive abnormality reduced with farm size. 7. Compared with the data collected in Korea, the reproductive efficiency was better, and lameness, metabolic problem and culling rate were higher in New Zealand

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Ultrastructure of Degenerating Axon Terminals in the Basal Forebrain Nuclei of the Rat following Prefrontal Decortication (이마앞겉질을 제거시킨 흰쥐 앞뇌의 바닥핵무리에서 변성축삭종말의 미세구조연구)

  • Ahn, Byung-June;Ko, Jeong-Sik;Ahn, E-Tay
    • Applied Microscopy
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    • v.35 no.3
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    • pp.135-152
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    • 2005
  • Prefrontal cortex is a psychological and metaphysical cortex, which deals with feeling, memory, planning, attention, personality, etc. And it also integrates above-mentioned events with motor control and locomotor activities. Prefrontal cortex works as a highest CNS center, since the above mentioned functions are very important for one's successful life, and further more they are upgraded every moments through memory and learning. Many of these highest functions are supposed to be generated via forebrain basal nuclei (caudate nucleus, fundus striati nucleus, accumbens septi nucleus, septal nucleus, etc.). In this experiment, prefrontal efferent terminals within basal forebrain nuclei were ultrastructurally studied. Spraque Dawley rats, weighing $250{\sim}300g$ each, were anesthetized and their heads were fixed on the stereotaxic apparatus (experimental model, David Kopf Co.). Rats were incised their scalp, perforated a 3mm-wide hole on the right side of skull at the 11mm anterior point from the frontal O point (Ref. 13, Fig. 1), suctioned out the prefrontal cortex including cortex of the frontal pole, with suction instrument. Two days following the operations, small tissue blocks of basal forebrain nuclei were punched out, fixed in 1% glutaraldehyde-1% paraformaldehyde solution followed by 2% osmium tetroxide solutions. Ultrathin sections were stained with 1% borax-toluidin blue solution, and the stained sections were obserbed with an electron microscope. Degenerating axon terminals were found within all the basal forbrain nuclei. Numbers of degenerated terminals were largest in the caudate nucleus, next in order, in the fundus striati nucleus, in the accumbens septi nucleus, and the least in the septal nucleus. Only axospinous terminals were degenerated within the caudate nucleus and the fundus striati nucleus, and they showed the characters of striatal motor control system. Axodendritic and axospinous terminals were degenerated within the accumbens septi nucleus and the lateral septal nucleus, and they showed the characters of visceral limbic system. Prefrontal role in integrating the limbic system with the striatal system, en route basal forebrain nuclei, was discussed.

Cyanobacterial Bioassay (AGP test) on the Water Fertility of Treated Wastewater Effluents Discharged into Euiam and Paldang Reservoirs, Korea (의암호 및 팔당호에 유입되는 주요 하수처리 방류수의 수질 비옥도 생물검정: Algal Growth Potential(AGP) Test)

  • Seo, Wanbum;Lee, Su-Woong;Kim, Keonhee;Park, Chaehong;Choi, Bong-Geun;Sim, Yeon Bo;Hwang, Soon-Jin;Shin, Jae-Ki
    • Korean Journal of Ecology and Environment
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    • v.50 no.1
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    • pp.79-95
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    • 2017
  • Euiam and Paldang Reservoirs have often been facing water quality problems, such as eutrophication, algal blooms and off-flavors by treated wastewater effluent (TWE) in the North-Han and the Han River basins, but little is examined on the direct biological effect of TWE. This study tested algal growth potential (AGP) of four TWEs discharged into Euiam and Paldang Reservoirs to evaluate water fertility in September 2014 and March and September 2015. Test alga was used Anabaena circinalis isolated from Paldang Reservoir. Mean concentration of T-N and T-P in TWEs was $3,956.7{\mu}g\;N\;L^{-1}$ and $50.8{\mu}g\;P\;L^{-1}$, and the proportion of $NO_3-N$ and $PO_4-P$ to the total fraction was 72.1% and 40.8%, respectively. Both N and P were high in TWEs, but much higher N than P concentration indicates strong P-limitation. As a consequence, the maximum AGP was determined by $PO_4-P$ concentration (r=0.998, p<0.01). Mean AGP value was $15.4mg\;dw\;L^{-1}$ among four effluents indicating its eutrophic condition. Due to the establishment of tertiary (advanced T-P) treatment method in the studied plants recently, P concentration was significantly decreased in TWEs compared to the years prior to 2012. However, P concentration seems to be still high enough to cause eutrophication and algal blooms. Therefore, wastewater treatment to P-free level needs to be considered if effluents are directly discharged into the drinking water resources.

A Study on the Christian Learning Environmental Arrangement in Church Educational Space (교회 교육공간에 관한 기독교교육적 환경구성)

  • Woo, Ji Yeon
    • Journal of Christian Education in Korea
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    • v.62
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    • pp.313-334
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    • 2020
  • As an element of education, the educational space cannot be separated from the purpose of education. The place of education is not only the passage to deliver actual curriculum, but also the purpose itself that can be accomplished through educational content. That is because the purpose of education cannot be achieved only with instructors, students, curriculum, and methods, but requires a change in the perception of the educational space that represents the goal and the place where it all can be implemented. Nevertheless, the problem that lies with educational space is easy to be overlooked and it has been rather considered as an issue related to the finances or scale of the church. The church educational space gives birth to faith and growth, where spiritual development and experience may occur. However, the reality follows the drawbacks of conventional school classroom arrangements and structures. In addition, even if the church educational space can be arranged according to the needs of its students, it cannot deviate much from the standard uniform format. In particular, the basic environment of church educational space is similar to that of standard school system in terms of arrangement of furniture such as chairs, desks, and its physical structure. As the school system was originally designed and tailored for the purpose of delivering knowledge and standardization, the space for church education must stay away from it. Humans are born and die in a space, where encounter with God also happens. Also, communication with God causes spacial conversion to humans, changing the place of their visitation. So the church educational space must be more meticulously designed and comprehensive than that of school which pursues physical, educational, psychological, social, and artistic purposes because the church educational space pursues the liturgical elements, as well. Therefore, the Christian learning environmental arrangements must seek liturgical elements, which is the major Christian value, by placing Christian artwork or symbols for church visitors. So in this research, I want to stress the role of Christian educational space for spiritual growth and pursue intrinsic and extrinsic changes in learning environment, leading to a greater awareness of the Christian educational space.

Bioavailability and Feed Value of Starfish with Various Treatments (처리방법에 따른 불가사리의 이용율 및 사료적 가치)

  • Choe, H.S.;Park, J.H.
    • Journal of Animal Environmental Science
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    • v.13 no.1
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    • pp.45-52
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    • 2007
  • To evaluate the feed value of starfish, antimicrobial effects of its extract, nutrients contents, concentration of amino acids and its bioavailability were tested. Steaming and ether processes were applied to obtain the extract from starfish for antimicrobial effects examination. The starfish was dried at $60^{\circ}C$ for 3 days before grinding for processing and fermentation. Ground starfish(GS), extruded starfish(ES), fermented starfish(EFS) were added with enzyme and without enzyme(Non enzyme fermented starfish : NEFS). Then the nutrient composition and bioavailability of those were analyzed. The extract from starfish showed no inhibition of the growth of lactobacillus and pathogenic bacteria. Protein content showed significantly higher 62.86% and 52.82%, respectively in EFS and NEFS than GS and EGS(p<0.05). The Ca content of GS, EGS, EFS and NEFS was 17.26%, 18.26%, 5.37% and 8.55%, respectively. It was low in EFS and NEFS due to measure the Ca content after fermentation. Total amino acid was 17.17 mg/g, 20.28 mg/g, 36.30 mg/g and 29.96 mg/g in GS, EGS, EFS and NEFS, respectively. The ratio of total amino acid to protein tended to show the similar tendency as total amino acid. Both total amino acid and its ratio to protein were increased by the fermentation. Bioavailability of the protein and Ca showed more 80% in EFS and NEFS. The nutrients availability of EFS were significantly higher in laying hens than other treatments. The results of these experiments indicate that starfish would be applied as a feed ingredients if it was properly treated.

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Effect of White and Red Panax ginseng Extract on Serum Lipids Level in High-fat-diet Fed Rats (백삼 및 홍삼추출물이 고지방 식이 급여 흰쥐의 혈청 지질 함량에 미치는 영향)

  • Sung, Jong-Hwan;So, Nam-Woo;Jeon, Bo-Hyun;Chang, Che-Chul
    • Journal of Ginseng Research
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    • v.28 no.1
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    • pp.33-38
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    • 2004
  • This study was carried out to determine the effect of white and red Panak ginseng on body weight gain, feed efficiency, epididymal fat weight, and total serum cholesterol and triglyceride levels in male rats (Wister/ST, 8-week-old, 320 g) fed high fat diet. Rats were divided largely into two groups; normal control (NC) and high-fat-diet (HFD)-fed groups. HFD-fed animals were subdivided into 2 groups; HFD-fed control (FC), and HFD- and ginseng-fed groups. HFD and ginseng fed animals were furthor subdivided into white (WG)- and red ginseng (RG)-treated groups. Ginseng-treated groups received ethanol extract at daily doses of 250, 500, 1,000 mg/kg b.w. for 4 weeks. Consequently, a total of 40 rats were divided into 8 groups. Body weight gain of WG-500 (P<0.05), WG1000 (P<0.01) and RG500 (P<0.05) was significantly lower than that of the NC. Feed efficiency showed same result. The epididymal fat weight of WG500, WG1000 and RG250 was markedly lower (P<0.05) than that in FC. Total serum cholesterol level of WG250, WG500, WG1000 and RG1000 groups were significantly lower (P<0.05) than that of FC. Decrease in the total cholesterol level was most significant in WG100 group. Treatment of ginseng significantly reduced serum free cholesterol and triglyceride levels of the HFD-fed rats irrespective of white or red ginseng. Among the test groups, administration of ginseng at daily dose of 1,000 mg/kg b.w. showed the most potent free cholesterol and triglyceride lowering activity. These results led us to the conclusion that administration of ginseng lowers serum total or free cholesterol and triglyceride levels in HFD-fed animals. Moreover the beneficial effect of white ginseng was slightly more potent than that of the red ginseng.

Analgesic Effects on the Oral Cavity by Electroacupuncture in Dogs (개에서 전침에 의한 구강 수술 시 진통효과)

  • Choi, Kyeong-Ha;Lee, Jae-Yeon;Park, Chang-Sik;Jeong, Seong-Mok;Kim, Duck-Hwan;Kim, Myung-Cheol
    • Journal of Veterinary Clinics
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    • v.26 no.6
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    • pp.568-573
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    • 2009
  • The purpose of this study is to evaluate the analgesic effects on the oral cavity in dogs which are treated with xylazine and electroacupuncture (EA). Furthermore, this study aims to find out its effects on glucose (GLU), serum alanine aminotransferase (ALT), and blood urea nitrogen (BUN) variation values, vital signs (rectal temperature, heart rate, respiratory rate) and pain responses to the noxious stimuli. Eight healthy dogs were randomly assigned to receive either xylazine or EA. Xylazine group dogs with weight of 3.6${\pm}$1.0 kg received 1.5 mg/kg of xylazine intramuscularly. EA group dogs with weight of 3.9${\pm}$1.0 kg received 1 volt (10-15 hz) for 5 minutes, and then 1-9 Volts (25-30 hz) for 60 minutes totally. The acupoints used were LI-3 (San Jian), LI-4 (He Gu) and ST-7 (Xia Guan). All dogs were examined before and 10, 25, 40, 55 and 120 minutes after administration of xylazine or EA. The mean rectal temperatures of the EA group were significantly higher than those of xylazine group after 25, 40 and 55 minutes (p < 0.05). The mean heart rates of the EA group were significantly higher than those of xylazine group after 10, 25, 40 and 55 minutes (p < 0.05). The mean respiratory rates of the EA group were significantly higher than those of xylazine group after 55 and 120 minutes (p < 0.05). The mean GLU concentration of the EA group were significantly lower than those of xylazine group after 55 and 120 minutes (p < 0.05). The sum of mean pain scores (SMPS) of the EA group were significantly higher than those of xylazine group after 10, 25 40 and 55 minutes (p < 0.05). In this study, the pain control of the EA group was shown to be better than that of the xylazine group. Also, there do not appear to be any negative physiologic effects associated with acupuncture-induced surgical analgesia. So, it was considered that these acupoints of EA analgesia might be useful for minor oral surgery in weak patients.