• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.608-611
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• 2005

In this paper the general equation of motion of damped sandwich beam including arbitrary viscoelastic material layer was derived based on the equation presented by Mead and Markus. The equation of motion of n-layered sandwich beam was represented by (n+3)th order ordinary differential equation. It was verified that the general equation of motion derived in this paper could represent the equations of motions for single-layered, three-layered, five-layered and multi-layered damped beam. Finite element method for the arbitrary-layered damped beam was formulated and programmed using higher order shape functions. Several numerical examples were implemented to show the effects of damped material.

• 한국전산유체공학회:학술대회논문집
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• 1998.11a
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• pp.7-12
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• 1998

Optimized high-order compact(OHOC) schemes were proposed, which have high spatial order of truncation and resolution to simulate the aeroacoustic problems due to unsteady compressible flows. Generally, numerical schemes are categorized explicit or implicit by time-marching method. In this research, OHOC differences which were developed with explicit time-marching method is used to have implicit formulation and the implicit OHOC differences result in block hepta-diagonal matrix. This paper presents the comparisons between the explicit and implicit OHOC schemes with a second order accuracy of time in the 1-d linear wave convection problem, and between the explicit OHOC scheme of 4th-order accuracy in time and the implicit OHOC scheme of 1st-order accuracy in tine for the 1-d nonlinear wave convection problem. With these comparisons, the characteristics of implicit OHOC scheme are shown in the point of CFL number.

• Journal of Periodontal and Implant Science
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• v.47 no.1
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• pp.20-29
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• 2017

Purpose: The microstructural characteristics of trabecular bone were identified using micro-computed tomography (micro-CT), in order to develop a potential strategy for implant surface improvement to facilitate osseointegration. Methods: Alveolar bone specimens from the cadavers of 30 humans were scanned by high-resolution micro-CT and reconstructed. Volumes of interest chosen within the jaw were classified according to Hounsfield units into 4 bone quality categories. Several structural parameters were measured and statistically analyzed. Results: Alveolar bone specimens with D1 bone quality had significantly higher values for all structural parameters than the other bone quality categories, except for trabecular thickness (Tb.Th). The percentage of bone volume, trabecular separation (Tb.Sp), and trabecular number (Tb.N) varied significantly among bone quality categories. Tb.Sp varied markedly across the bone quality categories (D1: $0.59{\pm}0.22mm$, D4: $1.20{\pm}0.48mm$), whereas Tb.Th had similar values (D1: $0.30{\pm}0.08mm$, D4: $0.22{\pm}0.05mm$). Conclusions: Bone quality depended on Tb.Sp and number-that is, endosteal space architecture-rather than bone surface and Tb.Th. Regardless of bone quality, Tb.Th showed little variation. These factors should be taken into account when developing individualized implant surface topographies.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1337-1358
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• 2016

The current study focuses on the assessment and interface response of reinforced concrete elements with composite materials (carbon fiber reinforced polymers-CFRPs, glass fiber reinforced polymers-GFRPs, textile reinforced mortars-TRM's, near surface mounted bars-NSMs). A description of the transfer mechanisms from concrete elements to the strengthening materials is conducted through analytical models based on failure modes: plate end interfacial debonding and intermediate flexural crack induced interfacial debonding. A database of 55 in total reinforced concrete columns (scale 1:1) is assembled containing elements rehabilitated with various techniques (29 wrapped with CFRP's, 5 wrapped with GFRP's, 4 containing NSM and 4 strengthened with TRM). The failure modes are discussed together with the performance level of each technique as well as the efficiency level in terms of ductility and bearing/ bending capacity. The analytical models' results are in acceptable agreement with the experimental data and can predict the failure modes. Despite the heterogeneity of the elements contained in the aforementioned database the results are of high interest and point out the need to incorporate the analytical expressions in design codes in order to predict the failure mechanisms and the limit states of bearing capacities of each technique.

• Preventive Nutrition and Food Science
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• v.17 no.2
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• pp.136-140
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• 2012

Trifoliate orange seed extracts (TSEs) were made using either distilled water (TW), ethanol (TE), or n-hexane (TH), to measure total polyphenol contents, DPPH and ABTS radical scavenging activities, and anti-complementary activity. The results showed that the total polyphenol content showed higher value at TE (235.24 ${\mu}g/mL$, p<0.05) than those of TW (132.65 ${\mu}g/mL$) and TH (165.44 ${\mu}g/mL$) at 10 mg/mL and TE exerted the highest DPPH radical scavenging activity (61.77%, p<0.05), which occurred in the following order: TE TW (56.87%)>TH (39.78%). The results of ABTS radical scavenging activity showed that TW (34.26%) and TE (31.81%) showed similar activities, which were higher than TH (12.74%, p<0.05). Anti-complementary activity of TE (61% at 500 ${\mu}g/mL$) showed a higher activity when compared with the positive control (60% at 1,000 ${\mu}g/mL$) polysaccharide-K (PSK), a known immuno-active polysaccharide from Coriolus versicolor. Consequently, among TSEs, TE is a byproduct from trifoliate orange and could be an important source of dietary polyphenolic antioxidant compounds and immunopotentiating activity, including complement activation.

• Journal of the Korean Chemical Society
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• v.14 no.4
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• pp.287-296
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• 1970

The varation of potential and completeness of reaction in an oxidation-reduction titration of Red$_1$ ($a\;Ox_1+N_1e{\leftrightarrow}b\;Red_1)\;by\;Ox_2\;(C\;Ox_2+n_2e{\leftrightarrow}d\;Red_2)$ is analyzed on the basis of general expressions. It is shown that the reaction deficiency as well as the rate of variation of the potential with titration fraction change in proportion to the $[n_2(a-b)-n_1(c-d)]$ th power of the concentration of the reagents. In particular, at the equivalence point, the expression of the potential contains a concentration dependent term that is proportional to ac-bd. Thus, the equivalence-point potential varies with the concentration of the reagents unless ac=bd is satisfied. It is also shown that the sharpness of the potentiometric titration curve is shown to occur either prior to or after the equivalence point depending upon whether $n_1cn_2b$, the deviation being the same order of magnitude as the relative deficiency at the equivalence point.

• Asian Journal of Turfgrass Science
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• v.5 no.1
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• pp.47-53
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• 1991

A laboratory experiment was conducted in order to learn the effect of a number of organic matters on the ammonification and nitrification of urea, and the reaction of soil, applied to a loamy upland soil poor in orgnic matter(<1.5%, without plants 1.The ammonification of urea was most pronounced in one week period immediatly after fertilizer and water treated, after which a rapid decrease of it was followed showing no accumulation at the end of 3rd week. Owing to the accumlation of ammonium, pHs of treated soils were read 7.0 to 7.3 from 6.8~6.9. 2.Nitrification was also progressed rapidly in the first one week period so that the accumulation of NO$_3$-N surpassed that of ammonia during this period. After the 1st week the accumulation of N0$_3$-N was continuously increased showing the maximum at the end of 4 weeks following a sharp decrease at the end of 5th weeks. The accumulation of NO$_3$-N dropped soil pH from 6.8-7.0 to 6. 0-6.2,but the decrease of NO-N at the end of 5th weeks brought up soil pH to 6.4-6.6. again. 3.Amino acid fermentation byproduct rich in salt, paticularly chloride, slowed down the ammonification and nitrification of urea. 4.The application of organic matter diminished the acidifying effect of chemical fertilizers. The diminishing effect of soluble humic acid and amion acid fermentation byproduct showed greater than that of solid organic matter in this experiment, which might be own to the application of a rather small amount of water soluble organic matters. Rice straw powder among solid organic matters appeared to be the least in the diminishing effect above. It may be reasoned that these soluble organic matters decomposes rapidly so as to affect Soil pH, but solid organic matters, particularly the rice straw powder, form acidic humus.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1232-1235
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• 2004

In order to investigate the effect of recombinant bovine somatotropin (rbST) on blood metabolites and milk yield of lactating buffaloes, 30 lactating buffaloes after acclimatization for 30 days were divided into 2 groups as control (n=10) and experimental (n=20). Animals were injected 250mg of rbST (Boostin-250) on 0, $14^{th}$ and $28^{th}$ day subcutaneously at ischiorectal fosse, where as control animals were given placebo of 2 ml normal saline. Fortnightly blood samples were collected from 15 days prior to 60 days post injection to estimate different blood metabolites. Daily milk yield was recorded and weekly average yield of each animal was calculated. From this study, it was found that blood metabolites such as glucose, triglycerides, total proteins, albumin, globulin and electrolytes like sodium and potassium were not altered by rbST injection. However, there was a significant (p<0.05) decrease in blood urea nitrogen (BUN) concentration in experimental group as compared to that of control group. The weekly average milk yield was significantly (p<0.001) higher (25%) in rbST injected group over the control group.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3409-3422
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• 2014

The frequency spectrum available for the wireless communication is extremely crowded. In order to improve the spectral efficiency, the two-way relay networks have aroused great attention. A simple $N^{th}$ best-relay selection criterion for the opportunistic two-way relay networks is proposed, which can be implemented easily by extending the distributed timer technique in practice, since the proposed criterion is mainly based on the channel gains. The outage performance of the proposed relay selection scheme is analyzed under the outdated channel state information (CSI), and a tight closed-form lower bound and asymptotic value of the outage probability over Rayleigh fading channels are obtained. Simulation results demonstrate that the tight closed-form lower bound of the outage probability very closely matches with simulated ones in the whole SNR region, and the asymptotic results provide good tight approximations to the simulation ones, especially in the high SNR region.

• Clinical and Experimental Reproductive Medicine
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• v.5 no.1_2
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• pp.1-7
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• 1978

In order to estimate the human placental lactogen levels and its value as an indicator of placental function during the first half of normal pregnancy, we defermined HPL levels. in normal snbjects (No=40) from the 6th week to the 20th week of gestation For the determination of human placental lactogen in serum of normal pregnant women during the first half of prognancy, radioimmunoassay have been performed using Phadebas HPL Test kit. The range of 25ng to 800ng HPL/ml. were determined by the procedures using Phadbas HPL Test kit, which correspond to levels recorded throughout the first half of normal pregnancy. HPL was detected in the earliest pregnancy samples collected at 6 weeks but was generally present in minute amount during the first trimester of pregnancy, when the HPL level ranged from 25 ng/ml. to 0.86 ${\mu}g$/ml. The mean concentration of HPL increased gradually from only 0.03 ${\mu}g$/ml, at 6 weeks to 0.25 ${\mu}g$/ml, at 12 weeks of gestation, Subsequently the mean HPL value rose steeply from 0.25 ${\mu}g$/ml, at 12 weeks to 1.65 ${\mu}g$/ml, at 20 weeks of gestation.