• Animal cells and systems
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• 제4권1호
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• pp.51-55
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• 2000

Mass loss and changes of mineral nutrients during the decomposition of mushrooms, Russula alboareolata and Lactarius violascens, were investigated for 7d from June 29 to July 5 in 1999 in an oak stand in Kongju, Korea. At 7d after installation of litterbags, the remaining mass of R. alboareolata and L. violaxcens was 9.4% and 25.9%, respectively. The mass loss rate of R. alboareolata was significantly higher than that of L. violascens. Concentration of N, P, K, Ca and Mg of R. alboareolata and L. violascens were 37.7 mg/g, 0.97mg/g, 38.25 mg/g, 0.04 mg/g, and 0.75 mg/g for R. alboareolata and 45.7 mg/g, 1.31mg/g, 24.0 mg/g, 0.06 mg/g, and 0.80 mg/g for L. violascens, respectively. Concentrations of nutrients in R. alboareolata and L. violascens were much higher than those in the surrounding leaf litter. N, P, Ca and Mg concentrations in the decomposing mushroom tissue were higher during the experimental period in both species than initial concentrations. Potassium increased during the first 3 d and then decreased in both species. Potassium contents in the mushroom were much greater than those of Ca and Mg. Except for Ca, there was no immobilization period in all the nutrients during decomposition. At 7 d after installation of litterbags, the remaining N, P, K, Ca and Mg of R. alboareolata and L. violascens were 9.8%, 8.9%, 2.7%, 47.7%, and 14.8% of the initial contents for R. alboareolata and 28.2%,30.5%, 19.6%, 199.9%, and 02.1% for L. violascens, respectively. Nutrients could be relocated spatially during the formation and decomposition of the Basidiomycetes fruiting body.

• The Journal of Advanced Prosthodontics
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• 제13권5호
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• pp.281-291
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• 2021

PURPOSE. To evaluate the wear of computer-aided design/computer-aided manufacturing (CAD-CAM) dental ceramic materials opposed by enamel as a function of increased chewing forces. MATERIALS AND METHODS. The enamel cusps of healthy human third molar teeth (n = 40) opposed by materials from CAD-CAM dental ceramic groups (n = 10), including Vita Enamic^® (ENA), a polymer-infiltrated ceramic network (PICN); GC Cerasmart^® (CERA), a resin nanoceramic; Celtra^® Duo (DUO), a zirconia-reinforced lithium silicate (ZLS) ceramic; and IPS e.max ZirCAD (ZIR), a polycrystalline zirconia, were exposed to chewing simulation (1,200,000 cycles; 120 N load; 1 Hz frequency; 0.7 mm lateral and 2 mm vertical motion). The wear of both enamel cusps and materials was quantified using a 3D laser scanner, and the wear mechanisms were evaluated by scanning electron microscopy (SEM). The results were analysed using Welch ANOVA and Kruskal Wallis test (α = .05). RESULTS. ZIR showed lower volume loss (0.02 ± 0.01 mm³) than ENA, CERA and DUO (P = .001, P = .018 and P = .005, respectively). The wear of cusp/DUO [0.59 mm³ (0.50-1.63 mm³)] was higher than cusp/CERA [0.17 mm³ (0.04-0.41 mm³)] (P = .007). ZIR showed completely different wear mechanism in SEM. CONCLUSION. Composite structured materials such as PICN and ZLS ceramic exhibit more abrasive effect on opposing enamel due to their loss against wear, compared to uniform structured zirconia. The resin nano-ceramic causes the lowest enamel wear thanks to its flexible nano-ceramic microstructure. While zirconia appears to be an enamel-friendly material in wear volume loss, it can cause microstructural defects of enamel.

• Journal of Biomedical and Translational Research
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• 제19권4호
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• pp.73-78
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• 2018

Osteoporosis is a major worldwide public health problem that poses a great economic burden to society. Puerariae Radix, the dried root of Pueraria lobata (Wild.) Ohwi, has been widely used in Asia. This study investigated the effects of Puerariae Radix (PR) on bone loss in ovariectomized (OVX) mice. C3H/HeN mice (10 weeks old) were divided into sham and OVX groups. The OVX mice were treated with vehicle, $17{\beta}-estradiol$ ($E_2$), PR (oral administration, 250 mg/kg/day) or PR (intraperitoneal administration, 50 mg/kg/every other day) for 6 weeks. Grip strength, uterus weight, serum alkaline phosphatase (ALP), estradiol concentration and osteoclast surface levels were measured. Tibiae were analyzed using microcomputed tomography. There were no significant differences in the degree of grip strength, body weight and uterine weight between OVX group and PR-treated group. As compared with the OVX group, the serum estradiol levels were significantly increased in the PR-treated group. PR (i.p.) significantly preserved trabecular bone volume, trabecular bone number, structure model index and bone mineral density of proximal tibiae metaphysic. The administration of PR lowered serum ALP and osteoclast surface levels in OVX mice, suggesting that PR can reduce the bone turnover rate in mice. The results indicate that the supply of PR can prevent OVX-induced bone loss in mice.

• Asian-Australasian Journal of Animal Sciences
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• 제18권3호
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• pp.420-426
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• 2005

Effect of pasture finishing on $\alpha$-tocopherol and $\beta$-carotene concentrations, drip loss, cooking loss, Warner-Bratzler shear force, fatty acid composition, meat color and metmyoglobin percentage of m. longissimus thoracis of Japanese Shorthorn steers was studied. Japanese Shorthorn steers (n=8), fattened indoors with a concentrate-based diet until they were 19 months of age were divided into two groups of four steers. Steers of the concentrate-fed group were fattened indoors with a concentrate-based diet until they were slaughtered. Steers of the pasture-fed group were fattened on pasture until they were slaughtered. The $\alpha$-tocopherol and $\beta$-carotene concentrations in the muscle of the pasture-fed group were higher (p<0.05) than those of the concentrate-fed group. The drip loss of the muscle of the pasture-fed group was lower (p<0.05) than that of the concentrate-fed group. Compared with the concentrate-fed group, the concentration of peroxidisable lipids (fatty acids with three or more unsaturated bonds) in the muscle of the pasture-fed group was high (p<0.05). The metmyoglobin percentage during display of the muscle of the pasture-fed group was higher (p<0.05) than that of the concentrate-fed group. These results suggested that pasture finishing decreased drip loss of the beef but lowered meat color stability.

• Nuclear Engineering and Technology
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• 제47권4호
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• pp.416-423
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• 2015

It had been disputed how to apply wall drag to the dispersed phase in the framework of the conventional two-fluid model for two-phase flows. Recently, Kim et al. [1] introduced the volume-averaged momentum equation based on the equation of a solid/fluid particle motion. They showed theoretically that for dispersed two-phase flows, the overall two-phase pressure drop by wall friction must be apportioned to each phase, in proportion to each phase fraction. In this study, the validity of the proposed wall drag model is demonstrated though one-dimensional (1D) simulations. In addition, it is shown that the existing form loss model incorrectly predicts the motion of the dispersed phase. A new form loss model is proposed to overcome that problem. The newly proposed form loss model is tested in the region covering the lower plenum and the core in a nuclear power plant. As a result, it is shown that the new models can correctly predict the relative velocity of the dispersed phase to the surrounding fluid velocity in the core with spacer grids.

• 대한치과보철학회지
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• 제24권1호
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• pp.33-43
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• 1986

The purpose of this study was to compare the wear resistance of heat pressure-cured microcomposite(SR-Isosit-N), photo-cured microcomposite(Dentalcolor), unfilled heat-cured resin(Thermojel) and that of human enmel. Specimens were made with specially designed die and finally polished with #3,000 diamond paste. After 100,000 strokes of tooth brushing at electric tooth-brushing machine, mean thickness loss of each specimen was measured by using surface profile and integration. The results were as follows 1. Mean thickness loss were $84.3{\pm}27.3{\mu}m$ in unfiled heat-cured resin, $9.4{\pm}2.5{\mu}m$ in photocured microcomposite, $7.6{\pm}2.1{\mu}m$ in heat.pressure-cured microcomposite and $0.97{\pm}0.42{\mu}m$ in enamel. 2. Heat.pressure-cured microcomposite and photo-cured microcomposite had no difference in mean thickness loss(p>0.05). 3. Unfilled resin and microcomposite had much differences in mean thickness loss (p<0.005). 4. ha resins used in this experiment had too much mean thickness loss as compared with enamel (p<0.005).

• Advances in environmental research
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• 제9권4호
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• pp.251-273
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• 2020

Soil degradation has become a major worldwide environmental problem, particularly in arid and semi-arid climate zones due to irregular rainfall and the intensity of storms that frequently generate heavy flooding. The main objective of this study is the use of geographic information system and remote sensing techniques to quantify and to map the soil losses in the Wadi Saida watershed (624 ㎢) through the revised universal soil loss equation model and a proposed model based on the surface erosive runoff. The results Analysis revealed that the Wadi Saida watershed showed moderate to moderately high soil loss, between 0 and 1000 t/㎢/year. In the northern part of the basin in the region of Sidi Boubkeur and the mountains of Daia; which are characterized by steep slopes, values can reach up to 3000 t/㎢/year. The two models in comparison showed a good correlation with R = 0.95 and RMSE = 0.43; the use of the erosive surface runoff parameter is effective to estimate the rate of soil loss in the watersheds. The problem of soil erosion requires serious interventions, particularly in basins with disturbances and aggressive climatic parameters. Good agricultural practices and forest preservation areas play an important role in soil conservation.

• Journal of applied mathematics & informatics
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• 제25권1_2호
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• pp.1-15
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• 2007

Consider a Rayleigh distribution with $$pdf\;p(x/{\theta})\;=\;2x{\theta}^{-1}\;{\exp}\;({-x^2}/{\theta})$$ and mean lifetime ${\mu}\;=\;\sqrt{\pi\theta}/2$. We study the two-action problem of testing the hypotheses $H_{0}\;:\;{\mu}{\leq}{\mu}_{0}$ against $H_{1}\;:\;{\mu}\;>\;{\mu}_{0}$ using a linear error loss of ${\mid}{\mu}\;-\;{\mu}_{0}{\mid}$ via the empirical Bayes approach. We construct a monotone empirical Bayes test ${\delta}^{*}_{n}$ and study its associated asymptotic optimality. It is shown that the regret of ${\delta}^{*}_{n}$ converges to zero at a rate $\frac{{\ln}^{2}n}{n}$, where n is the number of past data available when the present testing problem is considered.

• 한국세라믹학회지
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• 제22권6호
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• pp.80-86
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• 1985

Aluminum nitride (AlN) was synthesized from aluminum (Al) powders as a starting material in the tempe-rature range of 450~1, 15$0^{\circ}C$ in the presence of 90% $N_2$-10%$H_2$ gases. The thermogravimentric analysis showed that the nitridation of Al powders started at about 43$0^{\circ}C$ and escalated greatly from 53$0^{\circ}C$. The scanning electron microcopic observation revealed that AlN crystals were different in shape with varying temperature of nitridation. The crystals of AlN which were formed in the lower temperature than the melting point of Al were spherical while those of AlN in the higher temperature were fibrous. The yield of AlN was determined quantitatively by both XRD method and weight gain between before and after the nitridation of Al compacts. It was considered that the former was available for the specimen which was made in the high nitriding temperature. But the latter was unavilable for the same one probably because of the volatile loss of Al in the higher temperature.

• 대한수학회논문집
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• 제10권1호
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• pp.39-48
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• 1995

The ADI method was introduced by Peaceman and Rachford [6] in 1955, to solve the discretized boundary value problems for elliptic and parabolic PDEs. The finite difference discretization of the model elliptic problem $$ (1) -\Delta u = f, \Omega = [0, 1] \times [0, 1] $$ $$ u = 0 on \delta \Omega $$ with 5-point centered finite difference discretization, with n +2 mesh-points in the x - direction and m + 2 points in the y direction, leads to the solution of a linear system of equations of the form $$ (2) Au = b $$ where A is a matrix of dimension $N = n \times m$. Without loss of generality and for the sake of simplicity, we will assume for the remainder of this paper that m = n, so that $N = n^2$.