• 보존과학회지
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• 제33권6호
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• pp.417-429
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• 2017

연구는 풍납토성에서 출토된 백제시대 흑색마연토기의 태토를 분석하여 원료물질의 특성을 확인하고, 제작기법을 검토하였다. 분석된 흑색마연토기들은 표면부과 속심의 흑색 발현이 우수하고 입자의 정선도가 높은 그룹과 표면부만 흑색을 띠며, 정선도가 낮은 그룹으로 나누어진다. 두 그룹간 태토 정선과정, 발색시간, 발색 방법 등의 제작기법에 차이가 있었다. 또한 CaO, $P_2O_5$, L.O.I. 함량이 높게 검출되어 식물 재 성분을 표면에 침착시키는 방법이 사용되었을 것으로 판단된다. 표면부의 SEM-EDS mapping 결과, 흑색마연토기의 표면부에서 탄소의 농집 현상이 나타나 탄소의 영향을 받았을 것으로 추정된다. 반면 함께 출토된 회색토기의 표면부에서는 철의 농집 현상이 두드러지는데 고온소성 과정에서 표면부로 철의 이동이 있었을 것으로 추정된다. XRD 분석 결과를 통해 흑색마연토기는 $700{\sim}900^{\circ}C$ 이하에서, 회색토기는 $900{\sim}1000^{\circ}C$ 에서 소성되었을 것으로 판단된다.

• 대한의용생체공학회:의공학회지
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• 제26권2호
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• pp.123-127
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• 2005

Compression Hip Screw (CHS) is one of the most widely-used prostheses for the treatment of intertrochanteric fractures because of its strong fixation capability. Fractures at the neck and screw holes are frequently noted as some of its clinical drawbacks, which warrant more in-depth biomechanical analysis on its design variables. The purpose of this study was to evaluate changes in the strength with respect to the changes in design such as the plate thickness and the number of screw holes. Both mechanical test and FEM analysis were used to systematically investigate the sensitivities of the above-mentioned design variables. For the first part of the mechanical test, CHS (n=20) were tested until failure. The CHS specimens were classified into four groups: Group Ⅰ was the control group with the neck thickness of 6-㎜ and 5 screw holes on the side plate, Group Ⅱ 6-㎜ thick and 8 holes, Group Ⅲ 7.5-㎜ thick and 5 holes, and Group Ⅳ 7.5-㎜ thick and 8 holes. Then, the fatigue test was done for each group by imparting 50% and 75% of the failure loads for one million cycles. For the FEM analysis, FE models were made for each group. Appropriate loading and boundary conditions were applied based on the failure test results. Stresses were assessed. Mechanical test results indicated that the failure strength increased dramatically by 80% with thicker plate. However, the strength remained unchanged or decreased slightly despite the increase in number of holes. These results indicated the higher sensitivity of plate thickness to the implant strength. No fatigue failures were observed which suggested the implant could withstand at least one million cycles of fatigue load regardless of the design changes. Our FEM results also supported the above results by showing a similar trend in stress as those of mechanical test. In summary, our biomechanical results were able to show that plate thickness could be a more important variable in design for reinforcing the strength of CHS than the number of screw holes.

• Asian-Australasian Journal of Animal Sciences
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• 제20권7호
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• pp.1067-1075
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• 2007

Twenty eight 3-4 month old castrated Black Bengal kids (Capra hircus) were used to determine the effects of source and level of dietary copper (Cu) concentration on their performance and nutrient utilization. Cu was supplemented (0, 10, 20 and 30 mg/kg diet DM) as copper sulfate ($CuSO_4$, $5H_2O$) or copper proteinate (Cu-P). Kids were fed a basal diet containing maize (19.5%), soybean (17.0%), deoiled rice bran (56.5%), molasses (4.0%), di-calcium phosphate and salt (1.0% each) and mineral and vitamin mixture (0.5% each) supplements at 3.5% of body weight to meet NRC (1981) requirements for protein, energy, macro minerals and micro minerals, excluding Cu. The basal diet contained 5.7 mg Cu/kg, 122.5 mg Fe/kg, 110 mg Zn/kg, 0.26 mg Mo/kg and 0.32% S. $CuSO_4$ or Cu-P was added to the basal diet at the rate of 10, 20 and 30 mg/kg. Kids were housed in a well ventilated shed with facilities for individual feeding in aluminum plated metabolic cages. Blood samples were collected from the jugular vein on d 0, 30, 60 and 90 to determine hemoglobin (Hb), packed cell volume (PCV), total erythrocyte count (TEC), total leukocyte count (TLC) and serum enzymes (alkaline phosphatase, alanine transferase and aspertate transferase). A metabolism trial of 6 days duration was conducted after 90 days of experimental feeding. Statistical analysis revealed that source and level of Cu supplementation improved live weight gain (p<0.04) and average daily gain (p<0.01). No significant contribution of source and level of Cu to alter serum serum enzymes was evident. Goats fed Cu-P tended to have higher Hb, PCV and TEC than with $CuSO_4$ supplementation. Cu-P increased digestibility of ether extract (EE, p<0.02) and crude fiber (p<0.05) and showed an increasing trend (p<0.09) for digested crude protein (CP) and crude fiber (CF). Supplemental dose of Cu linearly improved (p<0.02) digestibilities of dry matter (DM), organic matter (OM), EE and nitrogen free extract (NFE). Though the absorption of nitrogen (N) was not affected (p>0.10) by both source and dose of Cu, N retention was affected (p<0.04) and there was a significant $Source{\times}Dose$ interaction (p<0.05). Final body weight (BW) was not influenced (p>0.10) by the source of Cu but increasing dose of Cu increased (p<0.04) the BW of kids. TDN intake (g/kg $W^{0.75}$) was higher (p<0.05) with the increased dose of Cu and there was a significant $Source{\times}Dose$ interaction. It was concluded that supplementation of Cu from different sources and varying dose level in a concentrate based diet may improve performance, nutrient utilization and plane of nutrition in castrated Black Bengal kids. The effects on performance and nutrient utilization are more pronounced with Cu-P than $CuSO_4$ supplementation. Higher dose of Cu showed better result than lower dose.

• Journal of Microbiology and Biotechnology
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• 제24권6호
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• pp.748-755
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• 2014

In the genome annotation of Escherichia coli MG1655, the orf382 (1,149 bp) is designated as a gene encoding an alcohol dehydrogenase that may be Fe-dependent. In this study, the gene was amplified from the genome by PCR and overexpressed in Escherichia coli BL21(DE3). The recombinant $6{\times}$His-tag protein was then purified and characterized. In an enzymatic assay using different hydroxyl-containing substrates (n-butanol, $\small{L}$-threonine, ethanol, isopropanol, glucose, glycerol, $\small{L}$-serine, lactic acid, citric acid, methanol, or $\small{D}$-threonine), the enzyme showed the highest activity on $\small{L}$-threonine. Characterization of the mutant constructed using gene knockout of the orf382 also implied the function of the enzyme in the metabolism of $\small{L}$-threonine into glycine. Considering the presence of tested substrates in living E. coli cel ls and previous literature, we believed that the suitable nomenclature for the enzyme should be an $\small{L}$-threonine dehydrogenase (LTDH). When using $\small{L}$-threonine as the substrate, the enzyme exhibited the best catalytic performance at $39^{\circ}C$ and pH 9.8 with $NAD^+$ as the cofactor. The determination of the Km values towards $\small{L}$-threonine (Km = $11.29{\mu}M$), ethanol ($222.5{\mu}M$), and n-butanol ($8.02{\mu}M$) also confirmed the enzyme as an LTDH. Furthermore, the LTDH was shown to be an ion-containing protein based on inductively coupled plasma-atomic emission spectrometry with an isoelectronic point of pH 5.4. Moreover, a circular dichroism analysis revealed that the metal ion was structurally and enzymatically essential, as its deprivation remarkably changed the ${\alpha}$-helix percentage (from 12.6% to 6.3%).

• 보존과학회지
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• 제36권2호
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• pp.143-151
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• 2020

본 연구에서는 인제 부평리유적 4-2지구 통일신라시대 제철유적에서 출토된 슬래그 5점에 대해 분석을 수행하였으며 그 결과를 통하여 당시의 제철공정을 밝히고자 하였다. 인제 부평리유적출토 슬래그의 전철량은 3.65~23.78%로 고대 제철에서 일반적으로 나타나는 전철량보다 상당히 낮았다. 조재량 또한 65.92~88.96%로 매우 높아 철과 슬래그의 분리가 원활하게 이루어졌을 것으로 보이며 그로 인해 철의 회수율이 상당히 좋았을 것으로 추정된다. 화합물 분석결과 대부분의 시료에서는 크리스토발라이트가 검출되었으며 FAS 상태도와 FCS 상태도에 분석된 데이터를 대입하여 추정한 노 내 온도 또한 1600℃ 이상으로 나타나 탄소를 포함한 철이 완전히 용융되어 주철을 생산하기에 충분한 온도로 조업이 이루어졌음을 확인하였다. 미세조직 관찰 결과 철편에서는 백주철 조직이 관찰되고 백주철 조직에서 철-탄소-인의 3원계 공정인 스테다이트가 함께 관찰되었다. 이는 제철부산물이 생성될 당시 주조 공정을 위한 간접제련이 이루어졌다는 증거가 된다. 분석결과를 토대로 인제 부평리유적은 철광석을 용해하여 선철을 생산한 간접제련유적인 것을 추정하였다.

• 보존과학회지
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• 제35권6호
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• pp.573-587
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• 2019

본 연구는 전통적인 철화분청사기 안료를 재현하기 위하여 국내산 자철석과 점토, 비가소성 원료를 혼합하여 재현시편을 제작하고, 발색이 양호한 30개의 시편들을 과학적으로 분석함으로써 유약의 발색특성을 알아보고자 하였다. 안료의 주원료인 자철석은 1,200℃의 환원 환경에서 짙은 흑색으로 발색하는 안료이나, 부가적으로 첨가되는 석회 성분과 반응하여 1,230℃ 산화 환경에서는 녹황색 계열로 변색된다. 적철석은 소성 온도 및 환경에 크게 영향을 받지 않으나 Fe를 10 wt% 이상 함유한 점토와 혼합하였을 때는 짙은 흑색으로 발색한다. 안료의 유동성은 R₂O₃/RO₂ 값에 의해 결정되며, 이는 발색에도 영향을 미친다. 미세조직 관찰에서 안료의 입자크기와 소성 환경에 따라 유약층의 발색과 철산화물 결정들이 일부 다른 양상을 보인다. 자철석을 원료로 한 안료는 1,200℃ 산화 환경에서는 유약층과 분장토의 경계면에 철산화물이 응집체 형태로 존재하며, 흑갈색으로 발색하지만, 환원 환경 소성에서는 철산화물의 응집체가 존재하지 않고 유약층에 균질하게 분포하며, 짙은 흑색으로 발색한다. 반면, 적철석을 기반으로한 안료는 산화 환경에서 유약층내 수지상 조직을 형성하며, 흑색으로 발색한다.

• 한국수산과학회지
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• 제42권6호
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• pp.609-613
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• 2009

This study was conducted to investigate the effects of dietary supplementation of $\beta$-1,3 glucan on growth, hematological and body composition in juvenile korean rockfish, Sebastes schlegeli fed the white fish meal based diets for 6 weeks. Four experimental diets were formulated to contain control (without supplementation of glucan), 0.05%, 0.1% and 0.5% (this diet was fed to fish daily, bi-weekly as three different dietary treatments) $\beta$-1,3 glucan per kg diet (Control, $D_{0.05}$, $D_{0.1}$, $D_{0.5}$, $B_{0.05}$, $B_{0.1}$, $B_{0.5}$). Fish averaging $4.0\pm0.1g$ (mean$\pm$SD) were randomly distributed in each aquarium as triplicate groups of 23 fish. Weight gain (WG, %) and specific growth rate (SGR, %) of fish fed $D_{0.5}$ diet were significantly lower than those of fish fed the other diets (P<0.05). Feed efficiency (FE) of fish fed $B_{0.05}$ diet was significantly higher than those of fish fed $D_{0.1}$, $D_{0.5}$, $B_{0.1}$ and $B_{0.5}$ diets (P<0.05). Protein efficiency ratio (PER) of fish fed $B_{0.05}$ diet was significantly higher than those of fish fed $D_{0.1}$ and $D_{0.5}$ diets (P<0.05). According to the results, the supplementation of 0.05% $\beta$-1,3 glucan daily and/or biweekly is optimum in juvenile Korean rockfish.

• 한국수산과학회지
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• 제42권3호
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• pp.243-249
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• 2009

This study was conducted to determine the proper inclusion levels of squid liver powder (SLP) and dehulled soybean meal (DHSM) as a fish meal (FM) replacement in the diets for olive flounders. All the experimental diets were formulated to be isonitrogenous (50% crude protein, CP) and isocaloric (17.1 kJ energy $g^{-1}$ diet). Four diet were formulation of FM with SLP (DHSM) were tested at 0, 25, 50, 75% (SLP(DHSM)$_0$, SLP(DHSM)$_{25}$, SLP(DHSM)$_{50}$ and SLP(DHSM)$_{75}$, respectively). Triplicate groups of 12 fish with an average body weight of 5.56$\pm$0.1 g (mean$\pm$S.D.) were fed one of three experimental diets for 7 weeks. Weight gain (WG) and the specific growth rate(SGR) of fish fed SLP(DHSM)$_0$ and SLP(DHSM)$_{25}$ diets were significantly higher than those of fish fed SLP(DHSM)$_{50}$ and SLP(DHSM)$_{75}$ diets (P<0.05). Also, WG and SGR of fish fed SLP(DHSM)$_{50}$ had significantly higher WG and SGR than that of fish fed SLP(DHSM)$_{75}$ (P<0.05). The feed efficiency (FE) and protein efficiency ratio (PER) of fish fed SLP(DHSM)$_0$ and SLP(DHSM)$_{25}$ were significantly higher than those fed SLP(DHSM)$_{50}$ and SLP(DHSM)$_{75}$ (P<0.05). The whole-body crude lipid content of fish SLP(DHSM)$_{75}$ was significantly higher than that of fish fed SLP(DHSM)$_{50}$ (P<0.05). However, there were no significant differences in whole-body moisture, crude protein and crude ash of fish fed all diets. Based on these growth performance results, the SLP(DHSM) combination replace up to 25% FM protein by the ANOVA test in juvenile olive flounder diets.

• 한국수산과학회지
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• 제43권4호
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• pp.314-319
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• 2010

This study determined the proper inclusion levels of squid liver powder (SLP) - soy protein concentrate (SPC) premix as a fish meal (FM) substitute in the diet for juvenile olive flounder (Paralichthys olivaceus). All the experimental diets were formulated to be isonitrogenous (50% crude protein) and isocaloric (17.1 kJ energy $g^{-1}$ diet). Five diets were formulated with SLP-(SPC) replacing 0, 25, 50, 75, and 100% of the FM (SLP $(SPC)_0$, SLP $(SPC)_25$, SLP $(SPC)_50$, SLP $(SPC)_75$, and SLP $(SPC)_100$, respectively). Triplicate groups of 12 fish averaging $5.56{\pm}0.10\;g$ ($mean{\pm}SD$) were fed one of the five experimental diets for 7 weeks. The weight gain (WG), specific growth rate (SGR), feed efficiency (FE), and protein efficiency ratio (PER) of fish fed SLP $(SPC)_0$ were significantly (P<0.05) higher than those of fish fed SLP $(SPC)_50$, SLP $(SPC)_75$ and SLP $(SPC)_100$, while those of fish fed SLP $(SPC)_0$ and SLP $(SPC)_25$ were similar. The whole-body crude protein content of fish fed SLP $(SPC)_0$ was significantly (P<0.05) lower than that of fish fed SLP $(SPC)_50$, SLP $(SPC)_75$, and SLP$(SPC)_100$, while those of fish fed SLP $(SPC)_0$ and SLP $(SPC)_25$ were similar. The whole-body crude lipid of fish fed SLP $(SPC)_0$ was significantly (P<0.05) lower than that of fish fed SLP $(SPC)_50$ and SLP $(SPC)_75$, while those of fish fed SLP $(SPC)_0$, SLP $(SPC)_25$ and SLP $(SPC)_100$ were similar. Based on the fish growth performance results obtained from this study, the SLP (SPC) premix can substitute up to 25% of the FM in the diets of juvenile olive flounder.

• 한국산학기술학회논문지
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• 제19권1호
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• pp.672-679
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• 2018

본 논문은 최적설계 시스템을 이용한 형상설계 방법론에 대해 설명하고 있으며, 일반적으로 3차원 해석은 설계를 위해 반드시 필요하다. 퍼지지식처리 수법과 계산기하학적 기법에 바탕을 둔 자동화된 유한요소 메쉬 생성 기법은 상용화된 유한요소해석코드와 솔리드모델러와 함께 시스템에 결합되어 있다. 또한, 다층형 신경망의 도움과 함께 개발된 시스템은 다차원 설계변수 공간에 존재하는 여러 만족하는 설계해인 디자인윈도우를 얻을 수 있게 해준다. 개발된 최적화 설계 시스템 사용된 부품을 평가하는데 성공적으로 적용하였다. 사이드 하우징 브라켓을 현장에서 사용되어지는 굴삭기의 힘과 유압브레이커의 작용하는 응력을 응력 게이지로 사이드 하우징 브라켓의 크랙 발생부위에 부착하여 최대응력이 얼마나 걸리는지를 측정하였다. 적용하는 대상을 현장에서와 동일한 조건하에서 최대응력이 허용응력보다 같거나 적게 하고, 기존형상 유지, 재질은 SM490, 중량 최소화 안전계수는 3으로 하여, 최대응력 값에 대한 해석을 수행하였다. 구조가 비교적 간단한 36톤용 사이드 하우징 브라켓을 최적화하였지만, 다른 클래스의(톤수 별) 사이드 하우징 브라켓 적용 시 품질향상에 크게 기여하리라 생각된다.