• Title/Summary/Keyword: end group effect

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Study on the Curing Properties of Photo-curable Acrylate Resins (광경화성 아크릴 수지의 경화특성에 관한 연구)

  • Kim, Sung-Hyun;Chang, Hyun-Suk;Park, Sun-Hee;Song, Ki-Gook
    • Polymer(Korea)
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    • v.34 no.5
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    • pp.469-473
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    • 2010
  • The curing mechanism and characteristics of UV curable acrylate resins were studied using Photo-DSC, FTIR, and Raman spectroscopy. Effects of chemical structures of acrylate, numbers of functional group, and UV intensity on curing kinetics were investigated with Photo-DSC. FTIR and Raman spectroscopy has been used to understand curing mechanisms and reaction conversion. In order to investigate the effect of oxygen on the photo-curing reaction, the curing process was compared between the acrylate and thiol-ene resins. The reaction conversion was found to be less than 80% for acrylate resins. The photo-curing reaction of the acrylate resin could not proceed to the end because of oxygen which acts as a reaction inhibitor while the thiol-ene resin was hardly affected from oxygen during the curing process.

Factors Associated with Early Adverse Events after Coronary Artery Bypass Grafting Subsequent to Percutaneous Coronary Intervention

  • Kamal, Yasser Ali;Mubarak, Yasser Shaban;Alshorbagy, Ashraf Ali
    • Journal of Chest Surgery
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    • v.49 no.3
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    • pp.171-176
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    • 2016
  • Background: A previous percutaneous coronary intervention (PCI) may affect the outcomes of patients who undergo coronary artery bypass grafting (CABG). The objective of this study was to compare the early in-hospital postoperative outcomes between patients who underwent CABG with or without previous PCI. Methods: The present study included 160 patients who underwent isolated elective on-pump CABG at the department of cardiothoracic surgery, Minia University Hospital from January 2010 to December 2014. Patients who previously underwent PCI (n=38) were compared to patients who did not (n=122). Preoperative, operative, and early in-hospital postoperative data were analyzed. The end points of the study were in-hospital mortality and postoperative major adverse events. Results: Non-significant differences were found between the study groups regarding preoperative demographic data, risk factors, left ventricular ejection fraction, New York Heart Association class, EuroSCORE, the presence of left main disease, reoperation for bleeding, postoperative acute myocardial infarction, a neurological deficit, need for renal dialysis, hospital stay, and in-hospital mortality. The average time from PCI to CABG was $13.9{\pm}5.4$ years. The previous PCI group exhibited a significantly larger proportion of patients who experienced in-hospital major adverse events (15.8% vs. 2.5%, p=0.002). On multivariate analysis, only previous PCI was found to be a significant predictor of major adverse events (odds ratio, 0.16; 95% confidence interval, 0.03 to 0.71; p=0.01). Conclusion: Previous PCI was found to have a significant effect on the incidence of early major adverse events after CABG. Further large-scale and long-term studies are recommended.

Effective Project Management Strategy Depending on Individual Self-efficacy and Task Characteristics under Multitasking Situation (멀티태스킹 상황에서 업무적 특성과 개인의 자기 효능감을 고려한 효율적인 프로젝트관리 전략)

  • Park, Jun-Young;Park, Do-Hyung
    • The Journal of Information Systems
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    • v.28 no.4
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    • pp.1-25
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    • 2019
  • Purpose The purpose of this study is to investigate cognitive mechanism of goal relations (Single-goal vs. Multiple-goals) and to-do list (Packing vs. Unpacking) and also verify the role of self-efficacy in the perspective of motivation belief. The perspective of cognitive mechanism is related to the effects of how the relations of multitasking environments affects to facilitating relation or conflicting relations. In pursuit of a single goal, judgement of task importance can be facilitated by unpacking effect due to relations of strongly associated project components including to-do list. On the other hands, in pursuit of multiple goals, judgement of task importance can be conflicted due to mutually exclusive relations of multiple goals. Additionally, the cognitive mechanism can be regulated from the role of self-efficacy, which contributes to motivation belief on how much a person is confident in achieving given tasks. In the end this research is to identify self-efficacy as boundary condition in inhibiting the effects of facilitation and conflict. Design/methodology/approach This study conducted Two-way ANOVA (Packing/ Unpacking * Single-goal/ Multiple-goals) to explore the effects of cognitive mechanism on task importance. After that we performed Three-way ANOVA, 2 (To-do list: Packing/ Unpacking) * 2 (Goal relation: Single-goal/ Multiple-goals) * 2 (Self-efficacy: Low self-efficacy/ High self-efficacy) to verify the role of self-efficacy between goal relations and to-do list. Findings In the cognitive mechanism, the task importance is not significantly different between in packed and in unpacked condition in pursuit of a single goal. But multitasking with multiple goals causes goal conflict, which means packed condition indicates significantly higher task importance than unpacked condition. Additionally, for a group with low self-efficacy unpacking leads to conflicting relation, which implies that packed condition is more efficient strategy than packed condition. On the other hands, in pursuit of mulitple goals, either packing or unpacking has no distinctive effects on task importance. However, participants with high self-efficacy are no longer affected by facilitating relation and conflicting relation as well in pursuit of either a single goal or multiple goals as well.

Subchronic Inhalation Toxicity Study of n-pentane in Rats

  • Kim, Jong-Kyu;Cho, Hae-Won;Han, Jeong-Hee;Lee, Sung-Bae;Chung, Yong-Hyun;Rim, Kyung-Taek;Yang, Jeong-Sun
    • Safety and Health at Work
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    • v.3 no.3
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    • pp.224-234
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    • 2012
  • Objectives: This study was conducted in order to obtain information concerning the health hazards that may result from a 13 week inhalation exposure of n-pentane in Sprague-Dawley rats. Methods: This study was conducted in accordance with the Organization for Economic Co-operation and Development (OECD) guidelines for the testing of chemicals No. 413 'Subchronic inhalation toxicity: 90-day study (as revised in 2009)'. The rats were divided into 4 groups (10 male and 10 female rats in each group), and were exposed to 0, 340, 1,530, and 6,885 ppm n-pentane in each exposure chamber for 6 hour/day, 5 days/week, for 13 weeks. All of the rats were sacrificed at the end of the treatment period. During the test period, clinical signs, mortality, body weights, food consumption, ophthalmoscopy, locomotion activity, urinalysis, hematology, serum biochemistry, gross findings, organ weights, and histopathology were assessed. Results: During the period of testing, there were no treatment related effects on the clinical findings, body weight, food consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, gross findings, relative organ weight, and histopathological findings. Conclusion: The no-observable-adverse-effect level (NOAEL) of n-pentane is evaluated as being more than 6,885 ppm (20.3 mg/L) in both male and female rats. n-pentane was not a classified specific target organ toxicity in the globally harmonized classification system (GHS).

Effect of Hempseed (Cannabis sativa sp.) Inclusion to the Diet on Performance, Carcass and Antioxidative Activity in Japanese Quail (Coturnix coturnix japonica)

  • Konca, Yusuf;Cimen, Behzat;Yalcin, Hasan;Kaliber, Mahmut;Beyzi, Selma Buyukkilic
    • Food Science of Animal Resources
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    • v.34 no.2
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    • pp.141-150
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    • 2014
  • This study was conducted to determine the effects of hempseed (H) on performance, carcass traits, and antioxidant activity in Japanese quail (Coturnix coturnix japonica). A total of 192 quail with seven-days old were divided into four experimental groups with four replicates. The treatments were; i) Control diet (C, no hempseed); ii) 5% hempseed in diet (H5); iii) 10% hempseed in diet (H10); and iv) 20% hempseed in diet (H20). The body weight (BW) and feed intake (FI) of quail was determined at 7, 21 and 42 d of age. At 42 d of age four quail were slaughtered and the carcass and internal organ traits were determined. Malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), nitric oxide (NO) and total protein were determined in the blood serum end of the experiment. The BW of the groups were not significant at 7 and 21 d, however in the 20% hempseed group BW decreased at 42 d (p<0.05). The FI and feed conversion ratio were not significant among the treatment groups. The carcass, liver, intestine and heart weight and their percentage to carcass were significantly differ in treatment groups (p<0.05). The serum MDA and NO decreased in hempseed addition (p <0.001). The serum SOD, CAT and GSH-Px were increased by hempseed supplementation (p<0.001). In conclusion, hempseed supplementation to quail diets may not improve quail performance traits but increase antioxidant activity in blood.

Effect of Methionine Supplementation on Performance and Carcass Characteristics of Awassi Ram Lambs Fed Finishing Diets

  • Obeidat, Belal S.;Abdullah, Abdullah Y.;Awawdeh, Mofleh S.;Kridli, Rami T.;Titi, Hosam H.;Qudsieh, Rasha I.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.6
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    • pp.831-837
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    • 2008
  • The objective of this study was to evaluate the effects of ruminally-protected methionine supplementation (0, 7, or 14 g/head/d) on nutrient intake, digestibility, growth performance, carcass, and meat characteristics of Awassi ram lambs fed finishing diets. Twenty four Awassi ram lambs ($16.8{\pm}1.17kg$ body weight) were randomly assigned to 3 treatment diets (8 lambs/treatment) and housed in individual pens. Lambs were given an adaptation period of 7 days before the intensive feeding period that lasted for 86 days. On day 74 of the trial, a digestibility experiment was performed. At the end of the trial (d 86), all lambs were slaughtered to evaluate carcass characteristics and meat quality. Increasing the level of methionine supplementation did not improve (p>0.05) performance nor feed conversion ratio. Nutrient intake and digestibilities were not influenced (p>0.05) by methionine supplementation. There were no differences in final weight, hot and cold carcass weights, dressing percentages or any of the measured non-carcass components. Tissues and fat depth measurements together with all meat quality attributes measured on longissimus muscle of the loin cut were not affected by methionine supplementation. The only meat quality parameters affected were redness (a*) and the hue angle being higher for the control group (p<0.05). These results suggest that methionine supplementation is not likely to produce any production benefits in nutrient digestibilities, performance or carcass characteristics of ram lambs fed a high performance diet.

Improving the Photo-stability of p-aramid Fiber by TiO2 Nanosol (TiO2 sol-gel 합성에 의한 파라 아라미드 섬유의 내광성 증진 연구)

  • Park, Sung-Min;Kwon, Il-Jun;Sim, Ji-Hyun;Lee, Jae-Ho;Kim, Sam-Soo;Lee, Mun-Cheul;Choi, Jong-Seok
    • Textile Coloration and Finishing
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    • v.25 no.2
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    • pp.126-133
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    • 2013
  • Although para-aramid fibers poss higher mechanical properties, they show very low resistance to sunlight exposure. This paper studied on the effect of nano-sol coated $TiO_2$ to improve the photo-stability of p-aramid fibers. Titanium dioxides were prepared by sol-gel method from titanium iso-propoxide at different R ratio ($H_2O$/titanium iso-propoxide). All samples were characterized by XRD, TEM and UV-vis spectrometer. The mechanical properties of p-aramid fabrics by $TiO_2$ nano-sol coating before and after sunlight irradiation were measured with tensile tester. XRD pattern of titanium dioxide particles was observed by mixing phase together with rutile and anatase type. The results showed, after sunlight irradiation, the decreased mechanical properties of the fiber. Furthermore, the sunlight irradiation obviously deteriorated the surface and defected areas of the fiber severely by photo-induced chain scission and end group oxidation in air.

The Lived Space of Mathematics Learning: An Attempt for Change

  • Wong Ngai-Ying;Chiu Ming Ming;Wong Ka-Ming;Lam Chi-Chung
    • Research in Mathematical Education
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    • v.9 no.1 s.21
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    • pp.25-45
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    • 2005
  • Background Phenomenography suggests that more variation is associated with wider ways of experiencing phenomena. In the discipline of mathematics, broadening the 'lived space' of mathematics learning might enhance students' ability to solve mathematics problems Aims The aim of the present study is to: 1. enhance secondary school students' capabilities for dealing with mathematical problems; and 2. examine if students' conception of mathematics can thereby be broadened. Sample 410 Secondary 1 students from ten schools participated in the study and the reference group consisted of 275 Secondary 1 students. Methods The students were provided with non-routine problems in their normal mathematics classes for one academic year. Their attitudes toward mathematics, their conceptions of mathematics, and their problem-solving performance were measured both at the beginning and at the end of the year. Results and conclusions Hierarchical regression analyses revealed that the problem-solving performance of students receiving non-routine problems improved more than that of other students, but the effect depended on the level of use of the non-routine problems and the academic standards of the students. Thus, use of non-routine mathematical problems that appropriately fits students' ability levels can induce changes in their lived space of mathematics learning and broaden their conceptions of mathematics and of mathematics learning.

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Taurine supplementation in diet for olive flounder at low water temperature

  • Kim, Joo-Min;Malintha, G.H.T.;Gunathilaka, G.L.B.E.;Lee, Chorong;Kim, Min-Gi;Lee, Bong-Joo;Kim, Jeong-Dae;Lee, Kyeong-Jun
    • Fisheries and Aquatic Sciences
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    • v.20 no.9
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    • pp.20.1-20.8
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    • 2017
  • The objective of this study was to examine the effect of dietary supplementation of taurine for juvenile olive flounder (Paralichthys olivaceus) at low water temperature ($16.4{\pm}0.36^{\circ}C$). Fish meal (FM)-based diet was used as the control diet. Four other experimental diets were prepared by adding taurine to FM-based diet at 0.25, 0.50, 1.00, and 1. 50% (T1, T2, T3, and T4, respectively). Each experimental diet was fed to triplicate groups of fish (initial mean body weight, 19.5 g) for 10 weeks. At the end of the feeding trial, growth performance and feed utilization, hematological parameters, non-specific immune responses, whole-body proximate composition, and liver mRNA expression of insulin-like growth factor-1 (IGF-1) were investigated. Feed conversion ratio was significantly reduced while protein efficiency ratio was significantly increased in taurine-supplemented groups. Hematocrit and hemoglobin were also significantly increased while plasma cholesterol levels were decreased in taurine-supplemented groups than those in the control group. Nitroblue-tetrazolium, myeloperoxidase and lysozyme activities, and plasma immunoglobulin level were significantly increased by taurine supplementation. These results suggest that dietary taurine supplementation is effective in improving growth performances, feed utilization, and innate immunity of olive flounder in low water temperature season.

Effect of cumin essential oil usage on fermentation quality, aerobic stability and in vitro digetibility of alfalfa silage

  • Turan, Asli;Onenc, Sibel Soycan
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.8
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    • pp.1252-1258
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    • 2018
  • Objective: This study was carried out to determine the effects of cumin essential oil on the silage fermentation, aerobic stability and in vitro digestibility of alfalfa silages. Methods: Alfalfa was harvested at early bloom (5th cutting) stage in October and wilted for about 3 hours. The research was carried out at three groups which were the control group where no additive control was done (CON), cumin essential oil (CMN3) with 300 mg/kg and CMN5 with 500 mg/kg cumin essential oil addition. Alfalfa was ensiled in plastic bags. The packages were stored at $8^{\circ}C{\pm}2^{\circ}C$ under laboratory conditions. All groups were sampled for physical, chemical and microbiological analysis 120th day after ensiling. At the end of the ensiling period, all silages were subjected to an aerobic stability test for 7 days. In addition, enzimatic solubility of organic matter (ESOM), metabolizable energy (ME), and relative feed value (RFV) of these silages were determined. Results: pH level decreased in the cumin groups compared to CON (p<0.05), thus inhibiting proteolytic enzymes from breaking down proteins into ammonia. In addition, it increased ESOM amount, and concordantly provided an increase of ME contents. Similarly, dry matter intake and RFV ratio increased. After opening the silage, it kept its aerobic stability for three days. Conclusion: Cumin essential oil improved fermentation, and affected chemical and microbiological characteristics of silages. Especially the addition of 300 mg/kg cumin provided cell wall fractionation through stimulating the activities of enzymes responsible. It also increased the number and activity of lactic acid bacteria (LAB) through providing a development of LAB.