• Animal Bioscience
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• 제36권7호
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• pp.1059-1066
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• 2023

Objective: Present study was designed to evaluate the efficacy of Acacia nilotica bark extract as an alternative to antibiotic growth promoters in broilers. Methods: Six hundred, day-old broiler chicks were randomly divided into six groups (NC, without any supplementation; AB, NC+Zinc Bacitracin; PB, NC+Safmannan; ANBE1, NC+A. nilotica bark extract 0.1%; ANBE3, NC+A. nilotica bark extract 0.3%; ANBE5, NC+A. nilotica bark extract 0.5%), with ten replicates per group (10 chicks/replicate) and feeding trial was lasted for 35 days. Results: Results showed that weight gain (1,296.63 g) and feed conversion ratio (FCR, 1.59) of AB was better than NC, during the finisher phase. Overall FCR of AB (1.53), PB (1.54), and ANBE5 (1.54) was significantly (p<0.05) better than NC. From carcass parameters relative weight of wing and heart were highest in ANBE3 (2.5% and 1.51%, respectively). Significantly (p<0.05) highest blood glucose level was observed in NC (264.5 mg/dL) and highest albumin concentration was found in AB (1.46 mg/dL). In addition, antibody titer levels against ND and IBD were higher in ANBE5 than NC, while higher relative weight of bursa was observed in ANBE3 than NC. The villus height to crypt depth ratio in all experimental groups was better than NC. Conclusion: Acacia nilotica bark extract could be a suitable alternative to antibiotic growth promoters to support the growth in broilers.

• Toxicological Research
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• 제29권3호
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• pp.187-193
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• 2013

The effects of toluene in dimethylformamide (DMF)-induced hepatotoxicity were investigated with respect to the induction of cytochrome P-450 (CYP) and the activities of related enzymes. The rats were treated intraperitoneally with the organic solvents in olive oil (Single treatment groups: 450 [D1], 900 [D2], 1,800 [D3] mg DMF, and 346 mg toluene [T] per kg of body weight; Combined treatment groups: D1+T, D2+T, and D3+T) once a day for three days, while the control group received just the olive oil. Each group consisted of 4 rats. The activities of the xenobiotic metabolic enzymes and the hepatic morphology were assessed. The immunoblots indicated that the expression of CYP2E1 was considerably enhanced depending on the dosage of DMF and the CYP2E1 blot densities were significantly increased after treatment with both DMF and toluene, compared to treatment with DMF alone. The activities of glutathione-S-transferase and glutathione peroxidase were either decreased or remained unaltered after treatment with DMF and toluene, whereas the lipid peroxide levels were increased with increasing dosage of DMF and toluene. The liver tissue in the D3 group (1,800 mg/kg of DMF) showed signs of microvacuolation in the central vein region and a large necrotic zone around the central vein, in rats treated with both DMF (1,800 mg/kg) and toluene (D3T). These results suggest that the expression of CYP2E1 is induced by DMF and enhanced by toluene. These changes may have facilitated the accelerated formation of N-methylformamide (NMF) from toluene, and the generated NMF may directly induce liver damage.

• ALGAE
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• 제33권1호
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• pp.69-84
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• 2018

We examined the species diversity of Herposiphonia on Korean coasts, based on a combination of morphology and molecular analyses of the mitochondrial COI-5P DNA barcode marker and plastid rbcL gene. We report the presence of eight species including three novel species: H. donghaensis sp. nov., H. jejuinsula sp. nov., H. sparsa sp. nov., H. caespitosa, H. fissidentoides, H. insidiosa, H. parca, and H. subdisticha. Specimens were separated into eight clades in both the COI-5P and rbcL gene analyses, with 1.3-19.6 and 6.6-15% interspecific sequence divergence, respectively. These eight species are also distinguishable by several morphological characteristics such as: branching pattern (d/i pattern in H. donghaensis sp. nov. and H. sparsa sp. nov.; d/d/d/i pattern in others), shape of determinate branch (ligulate in H. fissidentoides; terete in others), number of vegetative trichoblasts (1-2 in H. insidiosa and H. sparsa sp. nov.; 3-4 in H. caespitosa; absent in others), and number of segments and pericentral cells in determinate branches. About three novel species revealed by our analyses, H. donghaensis sp. nov. is newly discovered, and H. jejuinsula sp. nov. and H. sparsa sp. nov. were previously reported in Korea as H. nuda and H. secunda, respectively. Our results show that DNA barcoding and rbcL analyses are useful for delimiting species boundaries and discovering cryptic species diversity in the genus Herposiphonia.

• 한국수소및신에너지학회논문집
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• 제14권3호
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• pp.247-257
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• 2003

To investigate the effect of preparing condition on the physical properties of carbon nanotubes suitable for optical applications, carbon nanotubes were synthesized by thermal chemical vapor deposition using Ni particles as a catalyst on stainless steel substrate and acetylene as a reactant gas. To examine the physical and optical properties, SEM, TEM, Ram an, UV-visible, and photoluminescence spectroscopy were used. The physical properties of carbon nanotubes such as diameter, degree of growth density and morphology were closely related to such experimental conditions as Ni particle size, growing pressure, and etching condit on of Ni particles, it appeared from the light absorbance and photoluminescence spectra of carbon nanotube mixture prepared with an addition of a photopolymer, P3HT(Poly(3-hexylthIop hene)) that carbon nanotube could do a role as a kind of electron acceptor for solar cell application.

• 식물분류학회지
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• 제38권4호
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• pp.509-522
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• 2008

The achene morphology of ten taxa (eight species and two varieties) of the genus Bidens L. (Asteraceae) in Korea was studied in detail using the stereo-microscopy (SM) and scanning electron microscopy (SEM). The size of achenes excluding the arista part is $3.0-19.5{\times}0.7-2.6 mm$. The pappus is made up of 2-4 aristae, and the length of arista is 2.2-5.6 mm long. The striations of barb are 1-3. The achene polymorphism is confirmed in six studied taxa (B. bipinnata, B. biternata, B. frondosa, B. parviflora, B. pilosa var. pilosa, B. tripartita var. tripartita). Four types of achene were recognized based on the shape and the number of arista per fruit. - Type A: oblong with two aristae (B. parviflora); Type B: oblong with three or more aristae (B. bipinnata, B. biternata, B. pilosa var. pilosa, B. pilosa var. minor); Type C: obovate with two aristae (B. frondosa, B. radiata var. radiata, B. radiata var. pinnatifida, B. tripartita var. tripartita); Type D: obovate with three or more aristae (B. cernua). Three surface patterns (i.e., spiral, smooth, and irregular straight in parallel) of barb are also distinguished. The achene surface can be recognized into three types (ribbed areolate, smooth, subfavulariate). Systematic implications of achene characters are also briefly discussed. On the basis of the achene characters, a key of Bidens taxa in Korea is provided.

• 한국해안·해양공학회논문집
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• 제31권5호
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• pp.320-333
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• 2019

양빈이 수행된 해빈의 침식률 산정을 위한 물리기반 해빈 지형모형이 제시되었다. 동수역학 모형은 OpenFOAM에 기반 한 tool box인 IHFOAM으로 구성되며, Morphology 모형은 부유사를 대상으로 한 이송확산방정식, 소류사 이송을 포함한 표사 수지 개념으로부터 유도된 Exner 식으로 구성하였다. 표사 이송여부, 부유사 농도저면 경계치, 소류사 이송률 산출과정에는 Shields Diagram, 삼차원 수치 모의된 유동계 정보로부터 직접 산출된 저면 전단응력이 활용된다. 본 논문에서 제시된 지형 모형을 검증하기 위해, 경사가 1/6인 단조 해안에서의 천수과정, 쇄파과정, 이에 따른 저면 변화를 수치 모의하였다. 모의결과 비선형 천수과정에서 예상되는 왜곡되고 왜도된 저면전단응력이 비교적 정확히 모의되었다. 또한 전빈에서 진행되는 쇄파로 인해 부유되고 침식된 표사가 up-rush에 의해 후빈으로 이동되어 형성되는 swash bar와 up-rush 정점에서 방향을 바꾸어 먼 바다 방향으로 진행되는 back-wash에 의해 쓸려간 표사가 수심증가에 따라 back-wash 흐름 강도가 약해지면서 퇴적하여 형성되는 breaker bar가 성공적으로 모의되는 것을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권7호
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• pp.2295-2298
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• 2012

We describe herein a three-dimensionally diverse micropatterning of poly(lactic acid), as a biopolymer, using 1-butyl-3-methylimidazolium-based room-temperature ionic liquids (bmim-based RTILs), [bmim]X (X = $SbF_6$, $PF_6$, $NTf_2$, Cl). Utilizing the hydrophobic bmim-based RTILs, [bmim]X (X = $SbF_6$, $PF_6$, $NTf_2$) and a phase separation technique, we were able to produce white and opaque membranes with a three-dimensional structure closely packed with particles ($10-50{\mu}m$ in diameter). The particlulate structure, made by the assistance of [bmim]$NTf_2$ and DCM, interestingly transformed to a fibrous structure by using a cosolvent, e.g., DCM/$CF_3CH_2OH$. When we used an increased amount of [bmim]$NTf_2$, the particles were effectively detached and macrosized ($100-500{\mu}m$ in diameter) and the oval-shaped beads were obtained in a powder form. By varying the counter-anion type of the imidazolium-based RTIL, for example from $NTf_2^-$ to $Cl^-$, the particulate 3D-morphology was once more transformed to a porous structure. These reserch results could be potentially useful, as a method to fabricate particulate scaffolds, fibrous or porous scaffolds, and beads as a biopolymer device in diverse fields including drug delivery, tissue regeneration, and biomedical engineering.

• Journal of the Korean Institute of Landscape Architecture International Edition
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• 제2호
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• pp.140-146
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• 2004

All-round development of urban greenery network morphology is an integrated part of urban space system. The greenbelt construction of the Middle Ring Line is capable of changing linear planning and merging the peripheral greenery construction with 3-D space design to jointly form a broad open space.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.392.1-392.1
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• 2014

Isoindigo based small molecules have attracted much attention in the field of optoelectronic devices due to their broad absorbance and high charge carrier mobilitiies. Herein, we investigate the field effect transistor characteristics of a series of isoindigo based donor-acceptor-donor (D-A-D) small molecules containing a variable number of thiophene moieties (named IDT, ID2T, and ID3T) which form pi-bridges between the D and A moieites and a different donor moiety (IDED). In order to improve the carrier mobility, 1-chloronaphthalene (CN) and 1,8-diiodooctane (DIO) as solvent additives were used. The film morphology, crystallinity and optical properties of the materials processed with various concentrations of solvent additives were investigated through atomic force microscopy (AFM), X-ray diffraction (XRD) and UV-vis absorption spectroscopy.

• 한국주조공학회지
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• 제23권3호
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• pp.130-136
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• 2003

Rheocasting of AZ91D magnesium alloys yielded the microstructure consisted of the spherical primary particles in the matrix which is different from conventional casting. Rheocast ingots were produced under various processing conditions using batch type rheocaster. Morphology of primary particles was changed from rosette-shape to spherical shape with increasing stirring rate$(V_s)$ and decreasing isothermal stirring temperature$(T_s)$. With increasing $V_s$, more effective shearing between the particles occurred rather than the agglomeration and clustering, so the primary particle size decreased. But with decreasing $T_s$, primary particle size increased mainly due to sintering and partially Ostwald ripening. The sphericity of primary particles increased with increasing $V_s$ and decreasing $T_s$ due to enhanced abrasion among the primary particles. The uniformity of primary particle size increased with increasing Vs and $T_s$.