• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.6
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• pp.352-357
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• 2016

Objectives: This study aimed to evaluate the stability of prosthetic screws from three types of craniofacial prostheses retention systems (bar-clip, ball/O-ring, and magnet) when submitted to mechanical cycling. Materials and Methods: Twelve models of acrylic resin were used with implants placed 20 mm from each other and separated into three groups: (1) bar-clip (Sistema INP, São Paulo, Brazil), (2) ball/O-ring (Sistema INP), and (3) magnet (Metalmag, São Paulo, Brazil), with four samples in each group. Each sample underwent a mechanical cycling removal and insertion test (f=0.5 Hz) to determine the torque and the detorque values of the retention screws. A servo-hydraulic MTS machine (810-Flextest 40; MTS Systems, Eden Prairie, MN, USA) was used to perform the cycling with 2.5 mm and a displacement of 10 mm/s. The screws of the retention systems received an initial torque of 30 Ncm and the torque values required for loosening the screw values were obtained in three cycles (1,080, 2,160, and 3,240). The screws were retorqued to 30 Ncm before each new cycle. Results: The sample was composed of 24 screws grouped as follows: bar-clip (n=8), ball/O-ring (n=8), and magnet (n=8). There were significant differences between the groups, with greater detorque values observed in the ball/O-ring group when compared to the bar-clip and magnet groups for the first cycle. However, the detorque value was greater in the bar-clip group for the second cycle. Conclusion: The results of this study indicate that all prosthetic screws will loosen slightly after an initial tightening torque, also the bar-clip retention system demonstrated greater loosening of the screws when compared with ball/O-ring and magnet retention systems.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.507-512
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• 2003

The LiN $i_{l-y}$ $Co_{y}$ $O_2$ samples were synthesized at 80$0^{\circ}C$ and 85$0^{\circ}C$, by the solid-state reaction method, from the various starting materials LiOH, L $i_2$C $O_3$, NiO, NiC $O_3$, $Co_3$ $O_4$, CoC $O_3$, and their electrochemical properties are investigated. The LiN $i_{l-y}$ $Co_{y}$ $O_2$ pre-pared from L $i_2$C $O_3$, NiO, and $Co_3$ $O_4$ exhibited the $\alpha$-NaFe $O_2$ structure of the rhombohedral system (space group; R3m). As the Co content increased, the lattice parameters a and c decreased. The reason is that the radius of Co ion is smaller than that of Ni ion. The increase in da shows that two-dimensional structure develops better as the Co content increases. The LiN $i_{0.7}$ $Co_{03}$. $O_2$［HOO(800,0.3)] synthesized at 80$0^{\circ}C$from LiOH, NiO, and $Co_3$ $O_4$ exhibited the largest first discharge capacity 162 mAh/g. The size of particles increases roughly as the valve of y increases. The samples with the larger particles have the larger first discharge capacities. The cycling performances of the samples with the first discharge capacity larger than 150 mAh/g were investigated. The LiN $i_{0.9}$ $Co_{0.1}$ $O_2$［COO(850,0.1)］ synthesized at 85$0^{\circ}C$ from L $i_2$C $O_3$, NiO, and $Co_3$ $O_4$ showed an excellent cycling performance. The sample with the larger first discharge capacity will be under the more severe lattice destruction, due to the expansion and contraction of the lattice during intercalation and deintercalation, than the sample with the smaller first discharge capacity. As the first discharge capacity increases, the capacity fading rate thus increases.increases.s.s.s.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.125-135
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• 2015

In this study our main focus is to verify the relationship between social value of transportation system and its perceived features. To achieve this objective, we investigated the value of public bike system (PBS) through willingness to pay (WTP) analysis using contingent valuation method (CVM) and the survey was conducted for 1726 respondents who live in Suwon, Korea. Moreover the determinants related to features related to bicycle use were also gathered. The estimated binary logistic regression and censored regression reveal that the value of PBS is influenced by perceived features towards bicycle use incorporating non-congestion, transportation mode like auto and bus, and high mobility system as well as other variables such as income, bicycle ownership etc. Furthermore the results show that the perceiving of positive features to bicycle use leads to higher social value of PBS. Based on the findings, we discuss the importance of pre-review for transport policy implementation, and also explore the possibilities for application to PBS.

• Journal of the Korean Electrochemical Society
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• v.11 no.2
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• pp.100-104
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• 2008

Titanium sheet metal substrates used in thin film batteries were wet etched and their surface area was increased in order to increase the discharge capacity and power density of the batteries. To obtain a homogeneous etching pattern, we used a conventional photolithographic process. Homogeneous hemisphere-shaped wells with a diameter of approximately $40\;{\mu}m$ were formed on the surface of the Ti substrate using a photo-etching process with a $20\;{\mu}m{\times}20\;{\mu}m$ square patterned photo mask. All-solid-state thin film cells composed of a Li/Lithium phosphorous oxynitride (Lipon)/$LiCoO_2$ system were fabricated onto the wet etched substrate using a physical vapor deposition method and their performances were compared with those of the cells on a bare substrate. It was found that the discharge capacity of the cells fabricated on wet etched Ti substrate increased by ca. 25% compared to that of the cell fabricated on bare one. High discharge rate was also able to be obtained through the reduction in the internal resistance. However, the cells fabricated on the wet etched substrate exhibited a higher degradation rate with charge-discharge cycling due to the nonuniform step coverage of the thin films, while the cells on the bare substrate demonstrated a good cycling performance.

• Fire Science and Engineering
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• v.15 no.4
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• pp.41-48
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• 2001

Halogen-based fire suppressing agents have been the most effective fire suppressants and widely used for flammable liquid and electric fire. However they have environmental problems causing stratospheric ozone depletion and globe warming. As a substitution of halon, fire suppression system using fine water mist is one of an effective fire suppressant. Suffocating and cooling effects of water mist are increased by the evaporation characteristics because it has droplet size less than 1,000 $\mu{m}$ and very large surface area. In this study, the extinguishing characteristics of fire was measured with changing of water mist droplet size, flow density; discharge pressure, and fire size. As a result, the extinguishing time of pool fire was shortened with the increase of flow density and in case of low flow density less than 0.5$\pm$0.05 ml/$\textrm{cm}^2$ . min, the extinguishing time was shortened with the increase of droplet size. The cycling discharge was effective for $\eta$-heptane pool fire, and total amount of water mist required to extinguish fire was reduced to a quarter compare with continuous discharge.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.832-839
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• 2007

In this study, a new bicycle system was developed to improve muscular strength using the Magneto-Rheological(MR) rotary brake. The friction load of the MR rotary brake is adjusted according to muscle strength of the subjects. The characteristic of muscular strength was studied with various friction loads of MR rotary brake. The friction load was occurred with the current, applied to the MR. rotary brake. Experiments was composed of several cycling trials for various friction loads. In training programs involving muscle improvement, it is necessary to confirm muscle activity and fatigue. To measure the muscle activity and fatigue, EMG signals of rectus femoris (RF), biceps femoris (BF), tensor fasciae latae (TFL), vastus lateralis (VL), vastus medialis (VAS), gastrocnemius (GAS), tibialis anterior (TA) and soleus (SOL) muscles were collected with surface electromyography and analyzed into time and frequency domain. The experimental results showed that the muscle activity according to the applied current to the MR rotary brake was significantly different. The more the current was applied, the higher value of the integrated EMG (IEMG) was obtained. Especially, the magnitude of IEMG of the RF, BF, TFL and VL varied in direct proportion to the current. However, there was not significant in the median frequency as the cycling time continue.

• Journal of Hydrogen and New Energy
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• v.18 no.3
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• pp.325-333
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• 2007

[ $LiNi_{0.995}Al_{0.005}O_2$ ], $LiNi_{0.990}Ti_{0.010}O_2$ and $LiNi_{0.0990}Al_{0.005}Ti_{0.005}O_2$ were synthesized with a combustion method by calcining in an $O_2$ stream at $750^{\circ}C$ for 36 h. The X-ray diffraction patterns of these synthesized samples showed $-NaFeO_2$ structure of rhombohedral system(space group; $R{\bar{3}}\;m$) with no evidence of impurities. Among these samples, $LiNi_{0.995}Al_{0.005}O_2$ exhibited comparatively high first discharge capacity and discharge capacity, and the best cycling performance. $LiNi_{0.995}Al_{0.005}O_2$ had the first discharge capacity of 165.2 mA h/g and a discharge capacity of 116.7 mA h/g at the 50th cycle at 0.1C rate. It showed the first discharge capacity of 141.0 mA h/g and a discharge capacity of 93.5 mA h/g at the 50th cycle at 0.5C rate.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.383-387
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• 1999

Objective: There is increasing evidence for the expression of rat in gene in several extrapituitary sites including testis and ovary. We also have demonstrated that the local LH expression in the rat epididymis and uterus, the major accessory sex organs in male and female reproductive system, respectively. Design: The present study was undertaken to elucidate whether the gene for LH receptor is expressed in rat uterus and whether the expressions of uterine LH and its receptor are differentially regulated during estrous cycle. Presence of the transcripts for rat LH receptor in the rat uterine tissue were confirmed by touchdown reverse transcription-polymerase chain reaction (RT-PCR). Results: In $LH{\beta}$ semi-quantitative RT-PCR, the highest expression level was shown in estrus stage. The level of ill receptor transcripts was also fluctuated during estrous cycle. In ovariectomized rats (OVX + Oil), the expressions of both uterine LH and LH-R were markedly reduced when compared to those from normal rats. Supplement with estradiol $17{\beta}$ to the ovariectomized rats (OVX + $E_2$) restored the expression levels of LH and its receptor to the levels in uteri from normal rats. Conclusion: Our findings indicated that 1) LH and its receptor gene are expressed in the rat uterus from cycling rats, 2) the expression of uterine LH and its receptor is mainly, if not all, under the control of ovarian sex steroid(s). These results suggested that the uterine LH may act as a local regulator with auto and/or paracrine manner, though the posibility that the pituitary LH may act directly on the regulation of uterine functions could not be discarded.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.277-277
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• 2010

The capacity of the carbonaceous materials reached ca. $350\;mAhg^{-1}$ which is close to theorestical value of the carbon intercalation composition $LiC_6$, resulting in a relatively low volumetric Li capacity. Notwithstanding the capacities of carbon, it will not adjust well to the need so future devices. Silicon shows the highest gravimetric capacities (up to $4000\;mAhg^{-1}$ for $Li_{21}Si_5$). Although Si is the most promising of the next generation anodes, it undergoes a large volume change during lithium insertion and extraction. It results in pulverization of the Si and loss of electrical contact between the Si and the current collector during the lithiation and delithiation. Thus, its capacity fades rapidly during cycling. We focused on electrode materials in the multiphase form which were composed of two metal compounds to reduce the volume change in material design. A combination of electrochemically amorphous active material in an inert matrix (Si-M) has been investigated for use as negative electrode materials in lithium ion batteries. The matrix composited of Si-M alloys system that; active material (Si)-inactive material (M) with Li; M is a transition metal that does not alloy with Li with Li such as Ti, V or Mo. We fabricated and tested a broad range of Si-M compositions. The electrodes were sputter-deposited on rough Cu foil. Electrochemical, structural, and compositional characterization was performed using various techniques. The structure of Si-M alloys was investigated using X-ray Diffractometer (XRD) and transmission electron microscopy (TEM). Surface morphologies of the electrodes are observed using a field emission scanning electron microscopy (FESEM). The electrochemical properties of the electrodes are studied using the cycling test and electrochemical impedance spectroscopy (EIS). It is found that the capacity is strongly dependent on Si content and cycle retention is also changed according to M contents. It may be beneficial to find materials with high capacity, low irreversible capacity and that do not pulverize, and that combine Si-M to improve capacity retention.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.441-453
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• 2019

Organic farming is considered an effective form of sustainable agricultural management. However, understanding of soil microbial diversity and composition under long-term organic and conventional farming is still limited and controversial. In this study, the Illumina MiSeq platform was applied to investigate the responses of soil bacterial and fungal diversity and compositions to organic farming (OF) and improved conventional farming (CF, applied straw retention) in the rice-wheat rotation system. The results highlighted that the alpha diversity of microbial communities did not differ significantly, except for higher bacterial diversity under OF. However, there were significant differences in the compositions of the soil bacterial and fungal communities between organic and conventional farming. Under our experimental conditions, through the ecological functional analysis of significant different or unique bacterial and fungal taxonomic members at the phyla and genus level, OF enhanced nitrogen, sulfur, phosphorus and carbon dynamic cycling in soil with the presence of Nodosilinea, Nitrospira, LCP-6, HB118, Lyngbya, GOUTA19, Mesorhizobium, Sandaracinobacter, Syntrophobacter and Sphingosinicella, and has the potential to strengthen soil metabolic ability with Novosphingobium. On the other hand, CF increased the intensity of nitrogen cycling with Ardenscatena, KD1-23, Iamia, Nitrosovibrio and Devosia, but enriched several pathogen fungal members, including Coniochaeta, Corallomycetella, Cyclaneusma, Cystostereum, Fistulina, Curvularia and Dissoconium.