• Journal of Electrical Engineering and Technology
• /
• 제10권3호
• /
• pp.1114-1123
• /
• 2015

Bushing is the key link to connect outer and inner insulating systems and also the essential electric accessory in electric power system, especially in the high voltage engineering (AC 1000kV, DC 800kV). This paper presented the experimental research of thermal aging characteristic of oil-paper insulation used in bushing. A thermally accelerated aging experiment at 90℃ was performed. The bushing models containing five layers of paper were sealed into the aging vessels and further aged for 250 days. Then several important parameters associated with the aging were observed and evaluated. The results showed that the degree of polymerization (DP) of papers gradually decreased. The DP values of outermost layer and middle layer fit well into the second-order kinematic model and first-order kinematic model, respectively. Less deterioration speed of the inter-layer paper than outer layer was confirmed by the variation of DP. Hydrolysis was considered as the main cause to this phenomenon. In addition, the logarithm of the furfural concentrations in insulation oil was found to have good linear relationship with DP of papers. Interestingly, when the aging time is about 250 days and DP is 419, the aging process reaches an inflection point at which the DP approaches the leveling off degree of polymerization (LODP) value. Both tanδ and acid number of oils increased, while surface and volume resistivity of papers decreased. The obtained results demonstrated that thermal aging and moisture absorbed in papers brought great influence to the degradation of insulating paper, leading to rapid decrease of DP and increase of the tanδ. Thus, the bushing should be avoided from damp and real-time monitoring to the variation of tanδ and DP values of paper is an effective way to evaluate the insulation status of bushing.

• Journal of Acupuncture Research
• /
• 제33권1호
• /
• pp.37-46
• /
• 2016

Objectives : The objective of this study is to evaluate the analgesic effects of Drosera rotundifolia L. pharmacopuncture on formalin-induced pain in Sprague-Dawley(SD) rats. Methods : In this experiment there were four groups, each with six SD rats. In the normal group (NOR), normal saline $40{\mu}L$ was injected at right KI3, and normal saline $40{\mu}L$ was injected at right hindpaw 35 minutes later. In the control group (CON), normal saline $40{\mu}L$ was injected at right KI3, and formalin 5 % $40{\mu}L$ was injected at right hindpaw 35 minutes later. In the Drosera rotundifolia L. pharmacopuncture 3 % group (DP3), Drosera rotundifolia L. pharmacopuncture 3 % $40{\mu}L$ was injected at right KI3, and formalin 5 % $40{\mu}L$ was injected at right hindpaw 35 minutes later. In the Drosera rotundifolia L. pharmacopuncture 5 % group (DP5), Drosera rotundifolia L. pharmacopuncture 5 % $40{\mu}L$ was injected at right KI3, and formalin 5 % $40{\mu}L$ was injected at right hindpaw 35 minutes later. We analyzed ultrasonic vocalization (USV), Substance P, aspartate aminotransferase(AST), and alanine aminotransferase(ALT). Results : In the early phase of USV, both DP3 and DP5 had an analgesic effect. In the late phase, DP5 had an analgesic effect compared to CON. Substance P in DP5 was significantly decreased compared to CON. In regards to blood AST and ALT, there was no significant difference among NOR, CON, DP3 or DP5. Conclusion : These results suggest that Drosera rotundifolia L. pharmacopuncture helps to reduce formalin-induced pain. It's mechanism is related to substance P, and Drosera rotundifolia L. pharmacopuncture has no influence on liver toxicity.

• 한국식품과학회지
• /
• 제27권4호
• /
• pp.631-634
• /
• 1995

계통이 다른 쌀 전분(일반계 3품종, 통일계 3품종)에서 열수 불용성 전분을 분리하고 그 전분의 구조적 성질을 조사하였다. 열수 불용성 전분의 아빌로오스 함량은 $2.7{\sim}6.1%$였다. 열수 불용성 전분의 사슬 분포는 ${\overline{DP}}\;55$ 이상의 부분이 $31.9{\sim}38.7%$, ${\overline{DP}}\;40{\sim}55$ 부분이 $12.3{\sim}18.0%$ 그리고 ${\overline{DP}}\;10{\sim}20$ 부분이 $48.5{\sim}50.4%$로서 각 품종별로 차이를 보였으며, ${\beta}$-한계 덱스트린의 분자 크기도 품종에 따라 차이를 보였다. 쌀의 열수 불용성 아밀로펙틴 분자 구조는 쌀 아밀로펙틴의 것과는 서로 달랐다. 이러한 결과는 쌀 전번의 열수 불용화는 각 품종에 따라 그 특성을 보이고, 아밀로펙틴의 분자 구조에 영향을 받고 있음을 알 수 있었다.

• Journal of Microbiology and Biotechnology
• /
• 제29권2호
• /
• pp.321-329
• /
• 2019

Hair loss, also known as alopecia, is a common dermatological condition of psychosocial significance; development of therapeutic candidates for the treatment of this condition is, hence, important. Silibinin, a secondary metabolite from Silybum marianum, is an effective antioxidant that also prevents various cutaneous problems. In this study, we have investigated the effect of silibinin on hair induction using three-dimensional (3D) cultured, human dermal papilla (DP) spheroids. Silibinin was found to significantly increase viability through AKT serine/threonine kinase (AKT) activation in 3D DP spheroids. This was correlated with an increase in the diameter of the 3D DP spheroids. The activation of the wingless and INT-1 (Wnt)/${\beta}$-catenin signaling pathway, which is associated with hair growth induction in the DP, was evaluated using the T cell-specific transcription factor and lymphoid enhancer-binding factor (TCF/LEF) transcription factor reporter assay; results indicated significantly increased luciferase activity. In addition, we were able to demonstrate increased expression of the target genes, WNT5a and LEF1, using quantitative real-time PCR assay. Lastly, significantly elevated expression of signature genes associated with hair induction was demonstrated in the 3D DP spheroids treated with silibinin. These results suggest that silibinin promotes proliferation and hair induction through the AKT and Wnt/${\beta}$-catenin signaling pathways in 3D DP spheroids. Silibinin can be a potential candidate to promote hair proliferation.

• Macromolecular Research
• /
• 제13권4호
• /
• pp.321-326
• /
• 2005

Photochromic diarylethene polymers (DPs) in which 1,2-bis(2-methylbenzo[b ]thiophene-3-yl)hexafluorocyclopentene (BTF6) were covalently grafted onto the polymer main chain as pendant photochromic units were newly synthesized and their photochromic properties were investigated using steady-state and picosecond timeresolved spectroscopies. Polysiloxanes substituted with BTF6 molecules were prepared by sol-gel process using a mixture of tetraethoxysilane (TEOS), a silylated BTF6, and an organically modified silane precursor in the presence of HCl. The polysiloxane film (DP1) prepared from $\omega-methoxy$ poly(ethylene glycol) 3-(triethoxysilyl) propylcarbainate (MPGSC) as the silane precursor showed a much lower glass transition temperature than that (DP2) from heptadecafluorodecyltrimethoxysilane (HDFTMS). The ring-closure quantum yields of DP1 and DP2 were determined to be 0.20 and 0.02, respectively. Such a large difference in the quantum yield was attributed to the polymer matrix environment of the free inner volume.

• 한국재료학회지
• /
• 제19권6호
• /
• pp.293-299
• /
• 2009

The microstructures and mechanical properties of Dual Phase (DP), Transformation-Induced Plasticity (TRIP), and Quenching & Partitioning (Q&P) steels were investigated in order to define the strengthening mechanism of 0.2 C steel. An intercritical annealing between Ac1 and Ac3 was conducted to produce DP and TRIP steel, followed by quenching the DP and TRIP steel being quenched at to room temperature and by the TRIP steel being austemperingaustempered-air cooling cooled the steel toat room temperature, respectively. The Q&P steel was produced from full austenization, followed by quenching to the temperature between $M_s$ and $M_f$, and then enriching the carbon to stabilize the austenite throughout the heat treatment. For the DP and TRIP steels, as the intercritical annealing temperature increased, the tensile strength increased and the elongation decreased. The strength variation was due to the amount of hard phases, i.e., martensite and bainite, respectively in the DP and TRIP steels. It was also found that the elongation also decreased with the amount of soft ferrite in the DP and TRIP steels and with the amount of the that was retained in the austenite phasein the TRIP steel, respectively for the DP and TRIP steels. For the Q&P steel, as the partitioning time increased, the elongation and the tensile strength increased slightly. This was due to the stabilized austenite that was enriched with carbon, even when the amount of retained austenite decreased as the partitioning time increased from 30 seconds to 100 seconds.

• 한국재료학회지
• /
• 제8권3호
• /
• pp.238-244
• /
• 1998

Sn-rich합금의 석출 현상을 조사하였다. 첫째, 대기중과 진공 중에서 용해된 90Sn-o10Bi(wt%)합금을 $140^{\circ}C$에서 용체화 처리한 후 석출반응을 조사하였다. 90Sn-10Bi(wt%)합금은 불연속 석출(DP)현상을 나타냈다. 공기 중에서 용융된 시료의 DP반응이 진공 중에서 용융된 시료보다 빠르게 진행되었다. 이것은 공기 중에서 용융하는 과정에서 시료에 용존된 산소에 의해 입계 에너지가 감소한 것에 기인하는 것으로 판단된다. 둘째, 용융 후 서냉 응고된 Sn-Bi(-In)합금을 $140^{\circ}C$이하의 온도에서 열처리하여 미세조직 변화를 조사하였다. 명확한 고경각 입계가 존재하지 않는 응고조직에서, 편석영역으로부터 DP반응이 진행되어 석출셈이 형성되었다. DP반응선단에는 반응계면이 관찰되었다. 이 현상은, 이제까지 알려진 바와는 다르게, DP반응이 반응 전에 존재하는 고경각 입계뿐만 아니라 재결정현상에 의해 새로운 석출계면이 생성될 수 있음을 의미한다. 이러한 재결정 현상은 확산에 의한 정합변형(coherency strain)으로 설명된다.

• Parasites, Hosts and Diseases
• /
• 제35권1호
• /
• pp.9-17
• /
• 1997

1993-1994년에 걸쳐 전국 10개 지역내 주택에서 수거한 집먼지내의 진드기류를 조사하였다. 집 먼지는 평소 가정주부가 사용하는 전기진공청소기내 횔터에 모아진 집먼지 중 10 g을 채취하여 wet sieving metrod 일부 보완하여 진드기류를 분리하였다 채집된 총 7,257개체의 진드기를 동정한 결과 4아목 18과 23속 23종을 확인하였는데 그 중 Rhyzoglyphus robini, Sancossania phwllophcgianus, Cheyletus trouessarti 및 Scheloribotes lotipes의 4종은 국내 미기록 종이었다 전국적으로 가장 널리 분포되어 있고 서식밀도가 높은 종은 nemntophago릴os Jnrinae(DF)로 전체의 65.3%였고 D. Pteronvssinus(DP)가 20.6% Twrophnsus putrescentiqe(TP)가 6.5%를 차지하였는데, 이들 3종이 함께 서식하는 가정은 62개 조사대상 중 24.6%였고. 2개종이 공존하는 가정은 48 1%. 한종만 서식하는 가정은 27.3%였다. DF가 우점 종인 가정은 59개 조사 가정 중 63.5% DP가 우점종인 가정은 29.6%였고 TP가 우점종인 가정은 6.9%였다. 지역적으로는 서울. 광주 인천 전주 정주 등지에서는 DF가 우세하였으나 영광 춘천. 부산 영도 등 대기습도가 비교적 높은(> 73% RH) 지역에서는 DP가 우세한 것으로 나타났다. 집먼지진드기의 서식밀도를 보면 집먼지 10g 중 1.000개체 이상인 가정이 2.9%. 500-999 개체의 가정이 4.3%. 100-499개체의 가정이 15.7%였고 99개체 이하의 밀도를 보인 가정이 70.0%를 차지하였으며 전혀 채집되지 않은 가정은 7.1%였다. 아파트와 단독주택. 건물면적 청소횟수. 가족수. 건축년수 등과 집먼지진드기 서식밀도간에는 상관관계를 보이지 않았다.

• Ocean Systems Engineering
• /
• 제6권3호
• /
• pp.265-287
• /
• 2016

The change of the global performance of a turret-moored FPSO (Floating Production Storage Offloading) with DP (Dynamic Positioning) control is simulated, analyzed, and compared for two different internal turret location cases; bow and midship. Both collinear and non-collinear 100-yr GOM (Gulf of Mexico) storm environments and three cases (mooring-only, with DP position control, with DP position+heading control) are considered. The horizontal trajectory, 6DOF (degree of freedom) motions, fairlead mooring and riser tension, and fuel consumptions are compared. The PID (Proportional-Integral-Derivative) controller based on LQR (linear quadratic regulator) theory and the thrust-allocation algorithm which is based on the penalty optimization theory are implemented in the fully-coupled time-domain hull-mooring-riser-DP simulation program. Both in collinear and non-collinear 100-yr WWC (wind-wave-current) environments, the advantage of mid-ship turret is demonstrated by the significant reduction in heave at the turret location due to the minimal coupling with pitch mode, which is beneficial to mooring and riser design. However, in the non-collinear WWC environment, the mid-turret case exhibits unfavorable weathervaning characteristics, which can be reduced by employing DP position and heading controls as demonstrated in the present case studies. The present study also reveals the plausible cause of the failure of mid-turret Gryphon Alpha FPSO in milder environment than its survival condition.

• Journal of Microbiology and Biotechnology
• /
• 제29권11호
• /
• pp.1830-1840
• /
• 2019

Loliolide is one of the most ubiquitous monoterpenoid compounds found in algae, and its potential therapeutic effect on various dermatological conditions via agent-induced biological functions, including anti-oxidative and anti-apoptotic properties, was demonstrated. Here, we investigated the effects of loliolide on hair growth in dermal papilla (DP) cells, the main components regulating hair growth and loss conditions. For this purpose, we used a three-dimensional (3D) DP spheroid model that mimics the in vivo hair follicle system. Biochemical assays showed that low doses of loliolide increased the viability and size of 3D DP spheroids in a dose-dependent manner. This result correlated with increases in expression levels of hair growth-related autocrine factors including VEGF, IGF-1, and KGF. Immunoblotting and luciferase-reporter assays further revealed that loliolide induced AKT phosphorylation, and this effect led to stabilization of β-catenin, which plays a crucial role in the hair-inductive properties of DP cells. Further experiments showed that loliolide increased the expression levels of the DP signature genes, ALP, BMP2, VCAN, and HEY1. Furthermore, conditioned media from loliolide-treated DP spheroids significantly enhanced proliferation and the expression of hair growth regulatory genes in keratinocytes. These results suggested that loliolide could function in the hair growth inductivity of DP cells via the AKT/β-catenin signaling pathway.