• Progress in Superconductivity
• /
• v.13 no.3
• /
• pp.195-202
• /
• 2012

In this paper, we designed Active Magnetic Bearing (AMB) for large scale Superconductor Flywheel Energy Storage System (SFESS) and PD controller for AMB. And we experimentally evaluated SFESS including hybrid type AMB. The radial AMB was designed to provide force slew rate that was sufficient for the unbalance disturbances at the maximum operating speed. The thrust AMB is a hybrid type where a permanent magnet carries the weight of the flywheel and an electromagnetic actuator generates the dynamic control force. We evaluated the design performance of the manufactured AMB through comparison of FEM analysis and the results of experimental force measurement. In order to obtain gains of PD controller and design a notch filter, the system identification was performed through measuring frequency response including dynamics for the AMBs, a power amp and a sensor using a sine swept test method after levitating the flywheel. Through measuring the current input of the AMBs and the orbit of a flywheel according to rotational speed, we verified excellent control performance of the AMBs with small amount current for the large scale SFESS.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.19 no.5
• /
• pp.268-276
• /
• 2009

In this study, activated carbon (AC) was treated with ferric ion by a sol-gel method. The compound (Fe-AC) was employed for the preparation of Fe-activated carbon/$TiO_2$, (Fe-AC/$TiO_2$) composites. The prepared Fe-AC/$TiO_2$ composites were characterized with surface properties, structural crystallinity, elemental identification and photocatalytic activity. The SEM results showed that ferric compounds and titanium dioxide were fixed onto the AC surfaces. The XRD results showed that Fe-AC/$TiO_2$ composites mostly contained anatase phase. EDX showed the presence of C, O, and Ti with Fe peaks in all samples. Its photocatalytic degradation effect was evaluated with the degradation behavior of the methylene blue (MB) solution. MB degradation could be attributed to the synergetic effects of adsorption, photo-degradation of $TiO_2$ and photo-Fenton of Fe component. The degradation rate for this photocatalysis was evaluated as a function of the concentration of the dye, the amount of $TiO_2$ and the pH. Photocataytic activity is good at activity pH.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.10 no.3
• /
• pp.361-370
• /
• 2003

Purpose: This study was done to identify nursing interventions performed by operating room nurses using the Perioperative Nursing Data Set (PNDS). Method: The data were collected from 88 operating room nurses, from August 1 to October 25, 2002 using the PNDS developed by the Association of Operating Room Nurses and translated into Korean. Nurses working in 2 university hospitals in Gwang-ju and 2 general hospitals in Seoul. Data were analyzed using the SPSS program. Result: There were 15 of 127 nursing interventions which the operating room nurses indicated were important and which they performed at least once a day. Conclusion: The operating room nurses consider interventions to prevent physical injury and patient centered care to be very important, but the performance rate for patient centered care was low. It shows that there is a need in education courses for patient centered care to be more strongly emphasized.

• Journal of the Korean Ceramic Society
• /
• v.23 no.3
• /
• pp.78-86
• /
• 1986

single crystals of various hexagonal ferrites were grown by a flux technique. For the growing experiment platinum crucibles of size 40 cc and a horizontal siliconit tube furnace were used. Charges consisted of the flux of BaO(SrO)/$B_2O_3$ and the composition of crystals in the system of BaO $(SrO)-Fe_2O_3-ZnO$. The BaO(SrO)/$B_2O_3$ molar ratio of the flux were varied from 1 to 3. Crystals up to 12.5mm in diameter were grown by slow cooling of melts from a maximum temperature of 1, 30$0^{\circ}C$or 1, 350$0^{\circ}C$ to 95$0^{\circ}C$ or 1, 00$0^{\circ}C$ The grown crystals exhibited a tabular hexagonal habits with very well developed ba-sal planes and narrow pyramidal faces of {1011} {1012} and {0001}. For the identification of the grown crystals X-ray diffraction studies were carried out. The effects of va-riations in flux ratio flux percentage and cooling rate on the quality of the grown crystals were studied. Cry-stal habits hillocks etch steps and growth spirals were observed by optical microscope. Magnetic properties of single crystals were measured.

• Convergence Security Journal
• /
• v.7 no.3
• /
• pp.95-100
• /
• 2007

Alternate Data Streams (ADS) in NTFS originally has developed to provide compatibility with Macintosh Hierarchical File System. However, it is being used by the malware writers in order to support hiding malwares or data for the purpose of anti-forensics. Therefore identifying if hidden ADSs exist and extracting them became one of the most important component in computer forensics. This paper proposes a method to detect ADSs using MFT information. Experiment reveals that proposed method is better in performance and detection rate then others. This method supports not only identification of ADSs which are being used by the operating systems but also investigation of both live systems and evidence images. Therefore it is appropriate for using forensic purpose.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.1
• /
• pp.124-130
• /
• 2008

Streptococcus (Strep.) agalactiae is one of the major pathogens of bovine mastitis and is the main cause of subclinical infection. This study attempted to develop a rapid PCR diagnosis procedure using milk samples collected on filter paper disks. Chromatographic filter paper was employed as the preservation media and kept at room temperature for one to four weeks. The revival rate of Strep. agalactiae kept on dried filter paper disks was affected by the pretreatment preservation time. The revival test suggested that not all the bacteria in artificially contaminated milk samples on the filter paper disks could be recovered. After that, a PCR based on the 16-23S intergenic spacer region of Strep agalactiae was performed. The results distinguished the strep. agalactiae from major pathogens of bovine mastitis at a $2{\times}10^2$ colony forming units (CFU)/ml level, which showed similar sensitivity to the results from liquid milk samples. The results also showed that milk samples collected on filter paper disks could be kept at room temperature for one to four weeks with little negative effect on sensitivity and specificity. The field test showed that the diagnostic sensitivity and specificity was 96.15% and 98.60%, respectively. In conclusion, the protocol will provide a rapid and economic procedure for the detection of bovine mastitis.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.4
• /
• pp.580-585
• /
• 2016

The objective of this study was to determine cow characteristics and farm management factors during the dry period associated with early postparturient intramammary infection (IMI) and subsequent clinical mastitis (CM). Data were collected three times: before drying off (P1), during the dry period (P2), and 5 to 14 days after calving (P3), using questionnaires and farm investigation. Milk samples were aseptically collected for bacterial identification at P1 and P3. Factors associated with IMI and CM were analyzed using multiple logistic regression models. The final model showed that IMI in early postpartum was significantly associated with full insertion of dry cow antibiotic, dry cows in barns with a combination of tie and free stalls, body condition score (BCS) in dry period and after calving, and milk yield before drying off. For IMI cows, factors significantly associated with clinical expression of mastitis were having daily barn cleaning, teat disinfected with alcohol before administration of dry cow therapy, BCS before drying off, milk yield before drying off, and days in milk at drying off. In conclusion, both cow and farm management factors are associated with the IMI rate and subsequent expression of clinical signs of mastitis in early postpartum cows.

• BMB Reports
• /
• v.41 no.10
• /
• pp.685-692
• /
• 2008

Colorectal cancer (CRC) is the third most common malignancy in the world. Because CRC develops slowly from removable precancerous lesions, detection of the disease at an early stage during regular health examinations can reduce both the incidence and mortality of the disease. Although sigmoidoscopy offers significant improvements in the detection rate of CRC, its diagnostic value is limited by its high costs and inconvenience. Therefore, there is a compelling need for the identification of noninvasive biomarkers that can enable earlier detection of CRC. Accordingly, many validation studies have been conducted to evaluate genetic, epigenetic or protein markers that can be detected in the stool or in serum. Currently, the fecal-occult blood test is the most widely used method of screening for CRC. However, advances in genomics and proteomics combined with developments in other relevant fields will lead to the discovery of novel non invasive biomarkers whose usefulness will be tested in larger validation studies. Here, non-invasive molecular biomarkers that are currently used in clinical settings and have the potential for use as CRC biomarkers are discussed.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2010.05a
• /
• pp.42.2-42.2
• /
• 2010

Recently, highly porous bone substitutes, which have interconnected open pore structure, have been focused on improving their mechanical properties and modifying their functions. Especially, it is highly required to develop functional gradient structured bone substitute which is available for controlling their material properties such as bioresorption rate and elastic modulus. Porous $ZrO_2$ scaffold was fabricated by the sponge replica method using PU sponge. After 3 times of dip coating and the subsequent oven drying, burning out and microwave sintering were carried out. Various $ZrO_2$-BCP powder mixtures were prepared depending on the ratio and coated on the $ZrO_2$ scaffold by dip coating process. X-ray diffraction analysis was performed to characterize the phase identification of the scaffolds. Microstructures of the bone substitutes were observed using scanning electron microscopy.

• Korean Journal of Digital Imaging in Medicine
• /
• v.10 no.2
• /
• pp.39-49
• /
• 2008

Extravasation of contrast material is a not infrequent complication of enhanced imaging studies and large volume extravasation may result in severe damage. Subcutaneous extravasation of the radiographic contrast medium is one of the complications of the contrast medium-enhanced procedures. Automated power injectors enable the contrast material to be delivered at a uniform high-flow-rate and as a nonfragmented bolus, and this is essential for many contrast material enhanced CT(computed tomography) applications. The major risk associated with the use of automated power injectors is the well known complication of contrast material extravasation at the injection site. Automated injection of CT contrast material can produce the compartment syndrome. Selection of the nonionic contrast material after careful evaluation of the intravenous administration site and monitoring of the patient during the use of a mechanical power injector may help minimize or prevent extravasation injuries. Early identification is important and conservative management is effective in most cases. Prevention of these injuries with the education of radiological technologist remains the ultimate aim.