• International Journal of Concrete Structures and Materials
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• v.9 no.4
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• pp.475-486
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• 2015

Mode II fracture toughness ($K_{IIc}$) of fiber reinforced concrete (FRC) has been widely investigated under various patterns of test specimen geometries. Most of these studies were focused on single type fiber reinforced concrete. There is a lack in such studies for hybrid fiber reinforced concrete. In the current study, an experimental investigation of evaluating mode II fracture toughness ($K_{IIc}$) of hybrid fiber embedded in high strength concrete matrix has been reported. Three different types of fibers; namely steel (S), glass (G), and polypropylene (PP) fibers were mixed together in four hybridization patterns (S/G), (S/PP), (G/PP), (S/G/PP) with constant cumulative volume fraction ($V_f$) of 1.5 %. The concrete matrix properties were kept the same for all hybrid FRC patterns. In an attempt to estimate a fairly accepted value of fracture toughness $K_{IIc}$, four testing geometries and loading types are employed in this investigation. Three different ratios of notch depth to specimen width (a/w) 0.3, 0.4, and 0.5 were implemented in this study. Mode II fracture toughness of concrete $K_{IIc}$ was found to decrease with the increment of a/w ratio for all concretes and test geometries. Mode II fracture toughness $K_{IIc}$ was sensitive to the hybridization patterns of fiber. The (S/PP) hybridization pattern showed higher values than all other patterns, while the (S/G/PP) showed insignificant enhancement on mode II fracture toughness ($K_{IIc}$). The four point shear test set up reflected the lowest values of mode II fracture toughness $K_{IIc}$ of concrete. The non damage defect concept proved that, double edge notch prism test setup is the most reliable test to measure pure mode II of concrete.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6469-6473
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• 2013

The aim of this study was to detect the efficiency of arsenic trioxide (ATO) alone or together with bortezomib to inhibit proliferation and induce apoptosis in a multiple myeloma (MM) RPMI 8266 cells. Mechanisms of action were also investigated. RPMI 8266 cells were treated with ATO alone and in combination with bortezomib for 24 hours, and cell viability was assessed by modified MTT. Annexin V-F1TC and PI staining was used to detect the apoptosis rate and cell cycling was investigated by flow cytometry, along with expression of cell surface death receptor-4(DR4) and death receptor-5 (DR5). Western blotting was applied to detect the expression of bcl-2, caspase-3, caspase-8, and caspase-9. As a result, the ATO combined with bortezomib group showed more inhibition of RPMI 8266 cell viability than theATO group. Expression of DR4 and DR5 on the cell surfaces, and the apoptosis rate were increased after treatment by ATO alone or combined with bortezomib. The cells appeared to arrest in G2/M phase after treatment. Expression of bcl-2 was more significantly decreased in the combination group, and that of caspase-3, caspase-8 and caspase-9 was significantly increased as well. Therefore, bortezomib can enhance ATO actions to induce apoptosis in RPMI 8266 cells, with decrease in expression of bcl-2 and increase of caspase-3, caspase-8 and caspase-9 proteins.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.7
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• pp.4151-4155
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• 2013

Background: To compare response evaluation criteria in solid tumours (RECIST) and volumetric evaluation (VE) for colorectal cancer with liver-limited metastasis. Patients and Methods: VE of liver metastases was performed by manual contouring before and after chemotherapy on 45 pairs of computed tomography (CT) images in 36 patients who suffered from metastatic colorectal cancer (mCRC) with liver metastasis only. Cohen kappa was used to compare the agreement between VE and RECIST. Pearson correlation was performed for their comparison after cubic root transformation of the aggregate tumor volumes. Logistic regression was done to identify clinical and radiographic factors to account for the difference which may be predictive in overall response (OR). Results: There were 16 partial response (PR), 23 stable disease (SD) and 6 progressive disease (PD) cases with VE, and 14 PR, 23 SD and 8 PD with RECIST. VE demonstrated good agreement with RECIST (${\chi}$=0.779). Discordant objective responses were noted in 6 pairs of comparisons (13.3%). Pearson correlation also showed excellent correlation between VE and RECIST ($r^2$=0.966, p<0.001). Subgroup analysis showed that VE was in slightly better agreement with RECIST for enlarging lesions than for shrinking lesions ($r^2$=0.935 and $r^2$=0.780 respectively). No factor was found predictive of the difference in OR between VE and RECIST. Conclusions: VE exhibited good agreement with RECIST. It might be more useful than RECIST in evaluation shrinking lesions in cases of numerous and conglomerate liver metastases.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.330-341
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• 2014

Andropogon gayanus is an important grass due to its high biomass production, drought tolerance and favorable growth on low fertility acidic soils. Currently, there is little research on the impact of growth stage on the nutritional quality or the degree of $CH_4$ production that may arise from this forage during ruminal fermentation. The objectives of this study were to determine the effects of regrowth stage of A. gayanus on its chemical composition, in vitro production of gas and CH4, as well as in vitro dry matter (DM) digestibility when grown under tropical Brazilian conditions and conserved as hay or as silage. The nutritional value of A. gayanus grass declined with increasing maturity; however digestible DM yield linearly increased. After 112 d of regrowth, A. gayanus produced higher quality silage (higher lactate and lower pH and butyrate content) and higher DM yield. However, the low levels of crude protein at this time would make protein supplementation a necessity for proper rumen fermentation. No differences in $CH_4$ kinetic parameters were found with advancing maturity or preservation method (hay or silage).

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.3
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• pp.422-430
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• 2014

Pasture-based automatic milking systems (AMS) require cow traffic to enable cows to be milked. The interval between milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation of grazed pasture with grazed soybean (Glycine max) with the hypothesis that incorporating soybean would increase voluntary cow traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were randomly assigned to two treatment groups (n = 90/group) with a $2{\times}2$ Latin square design. Each group was either offered treatments of kikuyu grass (Pennisetum clandestinum Hoach ex Chiov.) pasture (pasture) or soybean from 0900 h to 1500 h during the experimental period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean ${\approx}18$ L/cow/d) in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner) exiting pasture allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation) relative to pasture (4.7 kg/cow/d/allocation). Pasture cows predominantly replaced eating time with rumination. These findings suggest that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of alternative forages.

• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.471-477
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• 1997

A study detennined whether certain biochemical and physiological variables were altered during marginal Zn deficiency. Ten weaned crossbred Hereford Angus heifer calves, weighing $163{\pm}2kg$, were utilized. Five calves were fed a Zn - deficient (- Zn) brome-alfalfa hay diet containing 17 mg Zn/kg diet DM, and five calves were fed a Zn-adequate (+Zn) diet with 23 mg Zn/kg diet DM from $ZnSO_4$ added to the - Zn diet (total diet, 40 mg Zn/kg diet DM), for 32 d. At 21 d the - Zn calves had a reduction (p < .05) in feed efficiency. By 25 d, plasma Zn and alkaline phosphatase concentrations were reduced (p < .05) in the - Zn calves. Blood urea nitrogen, glucose, insulin, IGF-I, Cu plasma concentration and Zn and Cu concentrations of red blood cell (RBC) and liver were not altered (p > .05) by the - Zn diet through 25 d. In response to a single i. m. injection of dexamethasone (20 mg) on d 25, calves fed the two dietary Zn amounts showed no changes (p > .05) in plasma or RBC Zn and Cu concentrations, serum IGF-I, insulin, and glucose when measured at 6, 12, 24, 48, 72, and 96 h after injection. In response to an intradermal injection of phytohemagglutinin on d 30, cell mediated immune (CMI) response was reduced (p < .05) in the - Zn calves. These observations indicate that during a marginal Zn deficiency in calves, there was a decrease in feed efficiency, plasma Zn, serum alkaline phosphatase, and CMI response.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.312.1-312.1
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• 2014

Chalcopyrite계 화합물 반도체인 $Cu(InGa)Se_2$ (CIGS)는 직접천이형 에너지 밴드갭과 전파장 영역에 대하여 높은 광흡수계수($1{\times}$[10]^5/cm)를 가지므로 두께 $1{\sim}2{\mu}m$인 박막형태으로 고효율의 태양전지 제조가 가능하다. 또한, 박막공정의 저가 가능성을 나타내면서 전세계적으로 많은 연구와 관심을 받고 있고, 현재 상용화되어 있는 결정질실리콘 태양전지를 대체할만한 재료로 주목 받고 있다. 일반적으로, CIGS박막형 태양전지 구성은는 유리를 기판으로 하여 5개의 단위 박막인 Mo 후면전극, p형 반도체 CIGS 광흡수층, n형 반도체 CdS 버퍼층, doped-ZnO 상부 투명전극, $MgF_2$ 반사방지막으로 이루어진다. 이들 중에서 태양전지의 에너지 변환효율에 결정적인 영향을 미치는 구성된다. CIGS 광흡수층의 제조는 크게 진공법과 비진공방법으로 나뉜다. 현재까지 보고된 문헌에 따르면 CIGS 박막형 태양전지의 경우에 동시증발법으로 20.3%의 에너지 변환효율을 보였지만,는데, 이는 진공장비 특성상 공정단가가 높고 대면적화가 어렵다는 단점을 가진다. 따라서, 비진공법을 이용하여 광흡수층 제작하는 것이 기술적으로 진보할 여지가 크다고 볼 수 있다. 반면 현재 상용화되어 있는 결정질실리콘 태양전지를 대체할만한 방법으로 주목 받고 있는 비진공을 이용한 저가공정은 최근 15.5%의 에너지 변환효율이 보고 되었다. 비진공법에는 전계를 이용한 증착법 및 스프레이법으로 나뉘며, 이들 광흡수층 재료의 화학적 합성은 III족 원소인 In, Ga의 함량비에 따라 광흡수층의 에너지 밴드갭(1.04~1.5 eV) 조절이 가능하다. 따라서, 본 연구에서는 비진공법에 사용되는 CIGS재료의 화학적 합성조건을 변화시켜 III족 원소의 조성비 조절을 시도하였다. CIGS 분말 시료의 입자 형태와 크기를 FE-SEM을 이용하여 관찰하였고, 화합물의 성분비를 EDX 및 XRD 분석을 통해 Ga 함량에 따른 구조적 차이를 비교해 보았다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.6
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• pp.449-453
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• 2003

Ferroelectric YMnO$_3$ thin films were etched with Ar/Cl$_2$ and CF$_4$/Cl$_2$ inductively coupled plasma (ICP). The maximum etch rate of YMnO$_3$ thin film was 300 $\AA$/min at a Ar/Cl$_2$ gas mixing ratio of 2/8, a RF power of 800 W, a DE bias of 200 V, a chamber pressure of 15 mTorr, and a substrate temperature of 30 $^{\circ}C$. From the X-ray photoelectron spectroscopy (XPS) analysis, yttrium etched by chemical reactions with Cl radicals assisted by Ar ion bombardments in Ar/Cl$_2$ plasma. In CF$_4$/Cl$_2$ plasma, yttrium are remained on the etched surface of YMnO$_3$ and formed of nonvolatile YF$_{x}$ compounds manganese etched effectively by chemical reactions with Cl and F radicals. From the X-ray diffraction (XRD) analysis, the (0004) diffraction peak intensity of the YMnO$_3$ thin film etched in Ar/Cl$_2$ plasma shows lower value than that in CF$_4$/Cl$_2$ plasma. It indicates that the crystallinty of YMnO$_3$ thin film is more easily damaged by the Ar ion bombardment than the changes of stoichiometry due to nonvolatile etch by-products.s.

• Journal of Powder Materials
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• v.22 no.4
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• pp.229-233
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• 2015

Porous metallic glass compact (PMGC) are developed by electro-discharge sintering (EDS) process of gas atomized $Zr_{41.2}Ti_{13.8}Cu_{12.5}Ni_{10}Be_{22.5}$ metallic glass powder under of 0.2 kJ generated by a $450{\mu}F$ capacitor being charged to 0.94 kV. Functional iron-oxides are formed and growth on the surface of PMGCs via hydrothermal synthesis. It is carried out at $150^{\circ}C$ for 48hr with distilled water of 100 mL containing Fe ions of 0.18 g/L. Consequently, two types of iron oxides with different morphology which are disc-shaped $Fe_2O_3$ and needle-shaped $Fe_3O_4$ are successfully formed on the surface of the PMGCs. This finding suggests that PMGC witih hydrothermal technique can be attractive for the practical technology as a new area of structural and functional materials. And they provide a promising road map for using the metallic glasses as a potential functional application.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.53 no.4
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• pp.386-395
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• 2017

For scientific research, a number of acoustic surveys using commercial echosounders equipped in fishing vessels were conducted throughout the world; however, few studies were performed in South Korea. Hence, this research is an preliminary study for presenting the application of a sounder from a fishing vessel. The fishing operations using a pair trawler (7 Cheonghae) was conducted in the Northwest-Western sea of Jeju Island from 20 to 23 April, 2016. Substantial impulse noises and attenuated signals were eliminated by the latest algorithms. Acoustic signals were grouped into the fish aggregations and long layer-like signals. The fish aggregations appeared between 30 and 60 m, and long layer-like signals showed the diurnal vertical migration. Energetic, morphological and positional properties of the fish aggregations and layer-like signals were described. The fish aggregations appeared mainly between sunrise and sunset; however layer-like signals tended to be presented regardless of time in consideration of the time series analysis. On the basis of the consignment sales, Scomberomorus niphonius, the target species of F/V 7 Cheonghae, was the highest catch with 4,280 kg (74.6%) and might have appeared in fish aggregations and layer forms.