• Asian-Australasian Journal of Animal Sciences
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• 제28권4호
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• pp.519-529
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• 2015

The aims of this study were to determine the effects of feeding medium-roasted soybean meal (SBM) and corn dried distiller's grains with solubles (CDDGS) in dairy cows on milk production and income over feed costs. A randomized complete block design experiment was conducted with 24 crossbred multiparous Holstein Friesian dairy cows in early- and mid-lactation. Four dietary treatments were as follows: basal diet without feed substitute (Control), 7.17% dry matter (DM) roasted SBM replaced for concentrate (R-SBM), 11.50% DM CDDGS replaced for concentrate (DDGS), and 3.58% DM roasted SBM plus 5.75% DM CDDGS replaced for concentrate (SB-DG). The roasted SBM was produced using a medium-heated treatment at $100^{\circ}C$ for 180 min. Dry matter intake was not affected by feeding high rumen undegradable protein (RUP) sources, but the replacement of roasted SBM and CDDGS for concentrate significantly improved (p<0.001) RUP intake (0.90, 0.86, and 0.88 kg/d corresponding to R-SBM, DDGS, and SB-DG) compared to the control (0.61 kg/d). Feeding roasted SBM and CDDGS alone or in combination had no significant effect on milk composition of dairy cows (p>0.05), whereas milk yield was significantly increased by 3.08 kg/d in the SB-DG group relative to the control group (p<0.01). Net income was meaningfully increased (p<0.05) from 4th week post feeding, the SB-DG group reached the greatest net income ($3.48/head/d) while the control group had the lowest value ($2.60/head/d). In conclusion, the use of CDDGS alone or in combination with medium-roasted SBM as substitute for concentrate in lactating dairy cattle diet led to improved milk production and net income over feed costs without affecting total dry matter intake and milk composition, while feeding medium-roasted SBM seemed to show intermediate values in almost parameters.

• 한국태양에너지학회 논문집
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• 제31권5호
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• pp.113-118
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• 2011

In order to prevent incoming solar radiation, it is necessary to study about blinds' blocking out effects of heat that are installed at the balcony at an apartment house. To figure out the heating effects from the windows, a study for indoor thermal environment according to the location of blinds is also needed. In order to find out the changes of indoor thermal environment, we'll compare models of a house building with or without Venetian blinds: one place has an extended living room removing a balcony and another one has a normal balcony. The result is as follows. Without blinds, the place with an extended living room has benefits for saving heat compare to the place with a normal balcony. It's because the warm air heated by the incoming solar radiation moves into the living room through convection current and radiation which causes an increase of the indoor temperature. At an extended living room, the temperature difference from outside and inside, when blinds were installed inside, was $1.9^{\circ}C$ while it was $0.6^{\circ}C$ when the blinds were installed at outside of the balcony. It is evaluated that setting up the blind outside prevents much heat. At the space with a normal balcony, installing blinds at living room windows can save much heat compare to installing blinds at windows at the balcony. The indoor temperature was low when blinds were installed. It can be said that blinds block heat from the incoming solar radiation. Moreover, when blinds are installed, there is a big change of indoor temperature due to the radiation from the blinds' slat and convective activities in between the blinds and windows. This also has to be considered.

• 한국전기전자재료학회논문지
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• 제22권5호
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• pp.443-447
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• 2009

Bismuth-antimony-telluride based thermoelectric thin film materials were prepared by metal organic vapor phase deposition using trimethylbismuth, triethylantimony and diisopropyltelluride as metal organic sources. A planar type thermoelectric device has been fabricated using p-type $Bi_{0.4}Sb_{1.6}Te_3$ and n-type $Bi_{2}Te_{3}$ thin films. Firstly, the p-type thermoelectric element was patterned after growth of $5{\mu}m$ thickness of $Bi_{0.4}Sb_{1.6}Te_3$ layer. Again n-type $Bi_{2}Te_{3}$ film was grown onto the patterned p-type thermoelectric film and n-type strips are formed by using selective chemical etchant for $Bi_{2}Te_{3}$. The top electrical connector was formed by thermally deposited metal film. The generator consists of 20 pairs of p- and n-type legs. We demonstrate complex structures of different conduction types of thermoelectric element on same substrate by two separate runs of MOCVD with etch-stop layer and selective etchant for n-type thermoelectric material. Device performance was evaluated on a number of thermoelectric devices. To demonstrate power generation, one side of the device was heated by heating block and the voltage output was measured. The highest estimated power of 1.3 ${\mu}m$ is obtained at the temperature difference of 45 K.

• Molecules and Cells
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• 제41권8호
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• pp.762-770
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• 2018

Adiponectin, a hormone produced by adipose tissue, is very abundant in plasma, and its anti- and pro-inflammatory effects are reported. However, the mechanisms of these pro- and anti-inflammatory effects are not fully defined. Herein, we evaluated the dual inflammatory response mechanism of adiponectin in macrophages. Short-term globular adiponectin (gAd) treatment induced $I{\kappa}B{\alpha}$ degradation, $NF-{\kappa}B$ nuclear translocation, and $TNF-{\alpha}$ production in RAW 264.7 cells. Polymyxin B pretreatment did not block gAd-induced $I{\kappa}B{\alpha}$ degradation, and heated gAd was unable to degrade $I{\kappa}B{\alpha}$, suggesting that the effects of gAd were not due to endotoxin contamination. gAd activated IKK and Akt, and inhibition of either IKK or Akt by dominant-negative $IKK{\beta}$ ($DN-IKK{\beta}$) or DN-Akt overexpression blocked gAd-induced $I{\kappa}B{\alpha}$ degradation, suggesting that short-term incubation with gAd mediates inflammatory responses by activating the $I{\kappa}B/NF-{\kappa}B$ and PI3K/Akt pathways. Contrastingly, long-term stimulation with gAd induced, upon subsequent stimulation, tolerance to gAd, lipopolysaccharide, and CpG-oligodeoxynucleotide, which is associated with gAd-induced downregulation of IL-receptor-associated kinase-1 (IRAK-1) due to IRAK-1 transcriptional repression. Conclusively, our findings demonstrate that the pro- and anti-inflammatory responses to gAd in innate immune cells are time-dependent, and mediated by the activation of the $I{\kappa}B/NF-{\kappa}B$ pathway, and IRAK-1 downregulation, respectively.

• 보존과학회지
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• 제31권1호
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• pp.13-20
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• 2015

목조문화재는 수분의 영향으로 열화의 가속화가 진행되기 때문에 전통적으로 표면을 수분으로부터 차단하기 위해 들기름 및 동유와 같은 유지류를 도포하였다. 그러나 목조문화재에 적합한 유지류 코팅 방법 및 성능에 대한 체계적인 연구가 부족한 실정이다. 본 연구는 천연 유지류 3종과 오일스테인 2종의 목재의 방향별, 공시재의 시간 경과 및 유지류의 중탕 여부에 따른 방수 성능을 평가하여 현장 적용 가능성을 판단하였다. 건전 목재의 섬유방향에서 상온의 천연유지류 코팅제 방수성능은 대조군과 비교하여 약 79.2%를 차단하였으며, 특히 동유는 90.5%의 수분을 차단할 정도로 우수한 성능을 나타냈다. 2년간 실내에서 컨디셔닝을 실시한 경우 유지류의 방수 성능은 약 8.8% 감소하였다. 유지류를 중탕하여 사용할 경우 약 5.0%의 방수 성능이 향상되며, 특히 아마인유는 중탕하여 사용할 경우 약 9.6%의 방수 성능을 개선할 수 있다.

• 한국추진공학회지
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• 제26권1호
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• pp.1-11
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• 2022

가스터빈에서 연료는 분사기를 통해 연소기에 공급될 때까지 고온 환경에 노출된다. 탄화수소 연료는 고온 조건에서 코킹이 발생하여 코킹 물질이 연료관에 퇴적되거나 분사기 통로를 막을 수 있다. 본 연구에서는 가스터빈 내부에 위치한 연료관을 모사한 시편과 Jet A-1을 전기적인 장치들을 이용해 가열하였다. 스테인리스강 시편의 벽면 온도와 시편에 공급되는 Jet A-1의 온도를 변화시키며, Jet A-1 코킹시험을 수행하였다. 코킹이 발생한 시편들을 절단한 후 코킹 물질과 내부 표면을 에너지 분산 X-선 분석기와 전계방사형주사전자현미경을 통해 분석하였다.

• 문화기술의 융합
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• 제8권3호
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• pp.515-520
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• 2022

메타버스가 최근 여러 분야에서 많은 관심을 모으고 있다. 비대면 활동이 늘어나면서 메타버스는 현실 세계와 연동하여 경제적 가치 창출 외에도 사회적 교류와 문화 활동까지 그 영역을 확장해 나가고 있다. 메타버스는 AI, 빅데이터, 3D 그래픽, 5G, 클라우드 컴퓨팅과 같은 기술의 고도화에 따라 가상세계와 현실세계를 연결하여 새로운 가치를 창출하는 것으로 세계 유수의 기업들이 관심을 가지고 투자나 기술개발에 참여하고 있다. 이를 통해 경제·사회·문화에 혁신적인 변화가 예상된다. 그러나 가상세계와 현실세계가 연동되기 위해서는 아직 풀어야 할 과제가 많다. 또한 팬데믹 상황에 대응하는 비대면 사회 활동을 넘어서 다양한 산업에서 가상공간을 이용한 현실적 체험과 수익 창출을 위한 제품이나 서비스의 획기적인 발전이 이루어야 한다. 본 연구를 통해 메타버스의 본질과 현황 및 발전 그리고 적용분야를 분석하고 향후 예상되는 문제점을 도출하여 다가오는 메타버스 시대에 글로벌 경쟁력을 확보하기 위한 전략과 방안을 제시한다.

• 한국화재소방학회논문지
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• 제25권6호
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• pp.21-26
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• 2011

본 논문에서는 에너지원에 따른 이동전화기(SCH_W830) 배터리의 소손 패턴을 제시함으로써 소비자분쟁 해결의 자료로 활용하고자 한다. 실험이 진행될 때의 주위 온도는 $22{\pm}2^{\circ}C$, 습도는 40~60 %를 유지함으로써 신뢰성을 확보하였다. 실험에 사용된 이동전화기의 배터리 전압은 양극(+)과 음극 (1)(-) 사이의 전압은 4.19 V이며, 양극(+)과 음극 (2)(-) 사이의 전압은 4.18 V로 측정되었다. 일반화염 인가에 의한 이동 전화기의 난연성 시험은 한국산업규격(KS)을 적용하였으며, 일반화염이 30 sec 동안 외함에 인가되어도 내장된 배터리의 소손은 없는 것으로 확인되었다. 생리 식염수(NaCl, 0.9%)에 이동전화기를 180 sec 침수시킨 결과 배터리 단자 사이에 누설전류에 의한 발열로 탄화 및 용융이 발생한 흔적을 확인할 수 있었다. 전자레인지(MWO)를 이용하여 70 sec 동안 이동전화기를 가열하면 금속홀더, 충전용 커넥터, 안테나 등이 내장된 부분에서 용융 및 변색이 확인되며, 그 밖의 부분은 특이사항이 없는 것을 알 수 있다. 즉, 인가된 에너지원의 종류에 따라 이동전화기 외형의 탄화, 내장된 금속 및 유전체, 배터리 단자대의 손상 및 변형 등이 다르게 발생하지만 전압은 비교적 일정한 특성을 보이는 것으로 보아 연소의 확산 패턴, 금속의 용융 및 변형 부분의 특성을 종합적으로 고려하여 해석하면 소손 원인 판정이 가능하다.

• 한국주조공학회지
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• 제20권2호
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• pp.104-109
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• 2000

Three different white cast irons alloyed with Cr, V, Mo and W were prepared in order to study their abrasion wear behavior in as-cast and heat-treated conditions. The specimens were produced using a 15㎏-capacity high frequency induction furnace. Melts were super-heated to $1600^{\circ}C$, and poured at $1550^{\circ}C$ into Y-block pepset molds. Three combinations of the alloying elements were selected so as to obtain the different types of carbides : 3%C-10%Cr-5%Mo-5%W(alloy No. 1: $M_7C_3$ and $M_6C$), 3%C -10%V-5%Mo-5%W(alloy No. 2: MC and $M_2C$) and 3%C-17%Cr-3%V(alloy No. 3: $M_7C_3$ only). A scratching type abrasion test was carried out in the states of as-cast(AS), homogenizing(AH), air-hardening(AHF) and tempering(AHFT). First of all, the as-cast specimens were homogenized at $950^{\circ}C$ for 5h under the vacuum atmosphere. Then, they were austenitized at $1050^{\circ}C$ for 2h and followed by air-hardening in air. The air-hardened specimens were tempered at $300^{\circ}C$ for 3h. 1 ㎏ load was applied in order to contact the specimen with abrading wheel which was wound by 120 mesh SiC paper. The wear loss of the test piece(dimension: $50{\times}50{\times}5$ mm) was measured after one cycle of wear test and this procedure was repeated up to 8 cycles. In all the specimens, the abrasion wear loss was found to decrease in the order of AH, AS, AHFT and AHF states. Abrasion wear loss was lowest in the alloy No.2 and highest in the alloy No.1 except for the as-cast and homogenized condition in which the alloy No.3 showed the highest abrasion wear loss. The lowest abrasion wear loss of the alloy No.2 could be attributed to the fact that it contained primary and eutectic MC carbides, and eutectic $M_2C$ carbide with extremely high hardness. The matrix of each specimen was fully pearlitic in the as-cast state but it was transformed to martensite, tempered martensite and austenite depending upon the type of heat-treatment. From these results, it becomes clear that MC carbide is a significant phase to improve the abrasion wear resistance.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.61-68
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• 2021

Experiments of vertically upward steam-water two-phase flow have been carried out in single-side heated narrow rectangular channel with a gap of 3 mm. Flow patterns were identified and classified through visualization directly. Slug flow was only observed at 0.2 MPa but replaced by block-bubble flow at 1.0 MPa. Flow pattern maps at the pressure of 0.2 MPa and 1.0 MPa were plotted and the difference was analyzed. The experimental data has been compared with other flow pattern maps and transition criteria. The results show reasonable agreement with Hosler's, while a wide discrepancy is observed when compared with air-water two-phase experimental data. Current criteria developed based on air-water experiments poorly predict bubble-slug flow transition due to the different formation and growth of bubbles. This work is significant for researches on heat transfer, bubble dynamics and flow instability.