• Advances in materials Research
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• v.13 no.1
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• pp.63-86
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• 2024

Asphalt concrete (AC), is a mixture of bitumen and aggregates, which is very sensitive in the design of flexible pavement. In this study, the Marshall stability of the glass and carbon fiber bituminous concrete was predicted by using Artificial Neural Network (ANN), Support Vector Machine (SVM), Random Forest (RF), and M5P Tree machine learning algorithms. To predict the Marshall stability, nine inputs parameters i.e., Bitumen, Glass and Carbon fibers mixed in 100:0, 75:25, 50:50, 25:75, 0:100 percentage (designated as 100GF:0CF, 75GF:25CF, 50GF:50 CF, 25GF:75CF, 0GF:100CF), Bitumen grade (VG), Fiber length (FL), and Fiber diameter (FD) were utilized from the experimental and literary data. Seven statistical indices i.e., coefficient of correlation (CC), mean absolute error (MAE), root mean squared error (RMSE), relative absolute error (RAE), root relative squared error (RRSE), Scattering index (SI), and BIAS were applied to assess the effectiveness of the developed models. According to the performance evaluation results, Artificial neural network (ANN) was outperforming among other models with CC values as 0.9147 and 0.8648, MAE values as 1.3757 and 1.978, RMSE values as 1.843 and 2.6951, RAE values as 39.88 and 49.31, RRSE values as 40.62 and 50.50, SI values as 0.1379 and 0.2027 and BIAS value as -0.1 290 and -0.2357 in training and testing stage respectively. The Taylor diagram (testing stage) also confirmed that the ANN-based model outperforms the other models. Results of sensitivity analysis showed that the fiber length is the most influential in all nine input parameters whereas the fiber combination of 25GF:75CF was the most effective among all the fiber mixes in Marshall stability.

• ETRI Journal
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• v.26 no.6
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• pp.575-582
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• 2004

Fully-depleted silicon-on-insulator (FD-SOI) devices with a 15 nm SOI layer thickness and 60 nm gate lengths for analog applications have been investigated. The Si selective epitaxial growth (SEG) process was well optimized. Both the single- raised (SR) and double-raised (DR) source/drain (S/D) processes have been studied to reduce parasitic series resistance and improve device performance. For the DR S/D process, the saturation currents of both NMOS and PMOS are improved by 8 and 18%, respectively, compared with the SR S/D process. The self-heating effect is evaluated for both body contact and body floating SOI devices. The body contact transistor shows a reduced self-heating ratio, compared with the body floating transistor. The static noise margin of an SOI device with a $1.1\;{\mu}m^2$ 6T-SRAM cell is 190 mV, and the ring oscillator speed is improved by 25 % compared with bulk devices. The DR S/D process shows a higher open loop voltage gain than the SR S/D process. A 15 nm ultra-thin body (UTB) SOI device with a DR S/D process shows the same level of noise characteristics at both the body contact and body floating transistors. Also, we observed that noise characteristics of a 15 nm UTB SOI device are comparable to those of bulk Si devices.

• Fire Science and Engineering
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• v.34 no.2
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• pp.22-29
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• 2020

In this study, the fire patterns, heat emissions, and smoke generated by means of fire tests developed for representative combustibles in residential facilities were analyzed from among seven fire types. These combustibles were selected in a previous study to simulate real-world situations and professionalism required while dealing with these types of fires and develop the field commander training content. Consequently, the maximum heat dissipation was recorded as 728.6 kW, followed by the dissipation measured from the combination of a mattress and electric blanket, desk and chair, and TV and mattress. The total heat emission of sofas (226.2 MJ) and the combination of mattress and electric blanket (2,259.5 ㎡) was recorded. In this study, the scope of the tests was limited to the fire characteristics and characteristics of the combustibles, and it is expected that a simulation using various data acquisition methods and FDS would be performed and evaluated at a later stage.

• Journal of the Korean Applied Science and Technology
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• v.22 no.3
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• pp.204-211
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• 2005

The structure of nitrogen adsorption complex of fully dehydrated $Cd^{2+}$ ion exchanged zeolite-X, $|Cd_{46}(N)_{18}|[Si_{100}Al_{92}O_{384}]$, was determined in the cubic space group $Fd\overline{3}$ at 21(1) $^{\circ}C$ [a = 24.863(4) ] by single crystal X-ray diffraction analysis. The crystal was prepared by ion exchange in a flowing steam of 0.05 M aqueous solution $Cd(NO_3)_2$ : $Cd(O_2CCH_3)_2$ = 1:1 for five days, followed by dehydration at $500^{\circ}C$ and $2{\times}10^{-6}$ Tor. for two days, and exposured to 100 Tor. zeolitically dry nitrogen gas at 21(1) $^{\circ}C$. The structure was determined in atmosphere, and was refined within $F_0$ > $4{\sigma}(F_0)$ using reflection for which the final error can appear in indices $R_1$ = 0.097 and $wR_2$ = 0.150. In this structure, $Cd^{2+}$ ions occupied four crystallographic sites. Nine $Cd^{2+}$ ions filled the octahedral site I at the centers of hexagonal prisms (Cd-O = 2.452(16) ${\AA}$). Eight $Cd^{2+}$ ions filled site I' (Cd-O = 2.324(19) ${\AA}$). The remaining 29 $Cd^{2+}$ ions are found at two nonequivalent sites II (in the supercages) with occupancy of 11 and 18 ions. Each of these $Cd^{2+}$ ions coordinated to three framework oxygens, either at 2.159(15) or 2.147(14) ${\AA}$, respectively. Eighteen nitrogen molecules were adsorbed per unit cell and three per supercage.

• Microbiology and Biotechnology Letters
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• v.43 no.2
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• pp.91-96
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• 2015

Prions are proteinaceous infectious particles that cause neurodegenerative diseases, such as scrapie in sheep, bovine spongiform encephalopathy in cattle and Creutzfeldt-Jakob disease (CJD) in humans. Although the detailed process, regarding the abnormal conversion of prion proteins (PrP), remains to be fully elucidated, a number of environmental factors appear to affect the formation of misfolded PrP, termed PrP^Sc. Because oceanic algae contain mycosporine-like amino acids (MAAs), which exhibit cellular defensive activities under a variety of stress conditions, we investigated the level of PrP^Sc in prion-infected neuroblastoma cells using mycosporine-glycine, porphyra-334 and shinorine. When judged by the level of protease-resistant PrP^Sc in western blots, porphyra-334 and shinorine increased the level of PrP^Sc in cells, but mycosporine-glycine did not. The current results indicate that the MAAs tested in this study enhance the formation of PrP^Sc.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.180-188
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• 2015

To investigate the tendency of $Li^+$ exchange from polar organic solvents, $Li^+$-ion exchange into zeolite Y (Si/Al = 1.56) was attempted by undried methanol (crystal 1) and formamide (crystal 2) solvent. Two single crystals of Na-Y were treated with 0.1 M LiNO3 in each of the two solvents at 323 K, followed by vacuum dehydration at 723 K. Their structures were determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group $Fd{\bar{3}}m$, at 100(1) K. In both structures, $Li^+$ for $Na^+$ ions filled preferentially sites I' and II. The remaining $Na^+$ ions occupied sites I', II, and III' in both structures, in additional to above sites, and $Na^+$ ions occupied site I in crystal 2. While the 68 % exchange of $Li^+$ for $Na^+$ was achieved from undried methanol, only 40 % exchange was observed from undried formamide, indicating that the undried methanol was more effective than undried formamide as solvent for $Li^+$ exchange under the conditions employed.

• Journal of Life Science
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• v.6 no.3
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• pp.178-184
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• 1996

Aloe(Aloe vera LINNE) has been used as a home medicine for the past several thousand in the world, and has been studied on various chronic degenerative diseases such as atherosclerosis, myocardiac infarction and hypertension. SMAP8, learning and memory impairment animal mode, were fed basic or experimental diets with 1.0% of freeze dried(FD)-Aloe powder for 8 months. This study was designed to investigate the effects of Aloe on body weight gain, grading score of senescence(GSS), triglyceride, total and LDL-cholesterol levels, and atherogenic index in serum of SAMP8, and also designed to investigate the effects of Aloe on cholesterol accumultions in mitochondria and microsome fractions of SAMP8 brain. Body weight gain was consistently lower in aloe group than in control group, but no significantly differences between them. Grading score of senescence resulted ina marked decreases pf 20% in 1.0% Aloe group compared with control group. Administrations of 1.0% aloe resulted ina marked decreases in 15% and 20% of triglyceride and cholesterol levels, respectively, and also significantly decreased in 15% of LDL-cholesterol levels and atherogenic index in serum of SAMP8 compared with control group. Cholesterol accumulations were significantly inhibited in 20% and 10% of mitochondria and microsome fractions of SAMP8 brain, respectively, by administration of 1.0% Aloe. These results suggest that administration of Aloe mau not only effectively inhibit chronic degenerative diseases in serum of SAMP8, but may also improve learning and memory impairments of SAMP8 brain.

• Fire Science and Engineering
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• v.34 no.4
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• pp.7-12
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• 2020

A numerical study was conducted to investigate the effects of the spray characteristics of water mist on the attenuation of thermal radiation. The attenuation process of the thermal radiation, generated from a hot surface panel, passing through the water mist was calculated via Fire Dynamics Simulator (FDS), and the effects of the flow rate, droplet mean diameter, and spray injecting angle of the water mist were analyzed. The results indicated that the increase in flowrate and decrease in droplet size led to an increase in the attenuation of thermal radiation. As the thermal radiation passed through the spray droplets, the effect of the spatial distribution of spray droplets was verified by calculating the thermal radiation attenuation at different spray injecting angles. The results indicated that the radiation attenuation increases as the spray angle increases. This implies that a wider distribution of spray droplets, irrespective of the droplet size and flowrate, increases the attenuation effect on thermal radiation.

• Fire Science and Engineering
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• v.33 no.4
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• pp.50-58
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• 2019

The prediction performance of B-RISK was evaluated for the fire behaviors of combustibles in a compartment using Fire Dynamics Simulator (FDS). First of all, to predict the heat release rate (HRR) for two combustible sets, the HRR for one combustible set and the design fire curve were used as input values for B-RISK. Comparing results of B-RISK calculations with experimental data for two combustible sets, it was found that B-RISK results predicted insufficiently for fire growth rate of experimental data but there was good agreement for maximum HRR and total HRR with the experimental data. And the B-RISK results were used for input values of FDS to evaluate the fire behaviors of B-RISK results. Comparing results of FDS calculations with experimental data, the simulation results showed that the temperature and concentrations of O₂, CO₂ in the fire growth phase were different from the experimental data. However, when using the B-RISK result for percentile 70%, the simulation results sufficiently predicted the overall fire behaviors.

• Journal of the Korean Chemical Society
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• v.57 no.1
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• pp.12-19
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• 2013

The single-crystal structure of fully dehydrated partially $Li^+$-exchanged zeolite Y, ${\mid}Li_{50}Na_{25}{\mid}[Si_{117}Al_{75}O_{384}]$-FAU, was determined by single-crystal synchrotron X-ray diffraction techniques in the cubic space group $Fd\bar{3}m$ at 100(1) K. Ion exchange was accomplished by flowing stream of 0.1 M aqueous $LiNO_3$ for 2 days at 293 K, followed by vacuum dehydration at 623 K and $1{\times}10^{-6}$ Torr for 2 days. The structure was refined using all intensities to the final error indices (using only the 801 reflections with ($F_o$ > $4{\sigma}(F_o)$) $R_1/R_2=0.043/0.140$. The 50 $Li^+$ ions per unit cell are found at three different crystallographic sites. The 19 $Li^+$ ions occupy at site I' in the sodalite cavity: the $Li^+$ ions are recessed 0.30 ${\AA}$ into the sodalite cavity from their 3-oxygens plane (Li-O = 1.926(5) ${\AA}$ and $O-Li-O=117.7(3)^{\circ}$). The 20 $Li^+$ ions are found at site II in the supercage, being recessed 0.23 ${\AA}$ into the supercage (Li-O = 2.038(5) ${\AA}$ and $O-Li-O=118.7(3)^{\circ}$). Site III' positions are occupied by 11 $Li^+$ ions: these $Li^+$ ions bind strongly to one oxygen atom (Li-O = 2.00(8) ${\AA}$). About 25 $Na^+$ ions per unit cell are found at four different crystallographic sites: 4 $Na^+$ ions are at site I, 5 at site I', 12 at site II, and the remaining 4 at site III'.