• Journal of Sensor Science and Technology
• /
• v.7 no.3
• /
• pp.188-196
• /
• 1998

The sensing and electrical characteristics of $WO_{3}$-based n-type semiconductor gas sensors are investigated. In normal air condition, $TiO_{2}$(4 wt. %)-doped $WO_{3}$-based sensor fabricated without any binder shows the grain boundary ( GB ) potential barrier height of 0.26 V. Sensors fabricated with alumina, PVA and silica sol binders show 0.17, 0.22 and 0.26 V of GB potential barrier height, respectively. In the ambience of 120 ppm $NO_{x}$ concentration, the GB potential barrier height of the sensor fablicated without binder is increased to 0.59 V. The sensors were fabricated with alumina, PVA, silica sol binders show 0.43, 0.66 and 0.52 V of potential barrier, respectively. Thus the variation of the potential barrier at GB is largest in the sensor fabricated with the PVA binder. This is found to be the main reason why the sensor fabricated with the PVA binder shows the best sensitivity. It is also found that the decrease of sensitivity at a temperature higher than the optimum operation temperature is due to the temperature dependence of the sensor resistance in normal air condition rather than the desorption of the adsorbed $NO_{x}$ gas particles. In the ambience of 250 ppm CO concentration, the GB potential barrier heights of the sensors fabricated without binder and with PVA binder are about 0.2 V showing negligible change compared to the case of normal air ambience. This fact indicates that these sensors are good candidates for the selective detection of $NO_{x}$ gas in the mixture of CO and $NO_{x}$ gases.

• Journal of Food Hygiene and Safety
• /
• v.33 no.3
• /
• pp.193-199
• /
• 2018

In this study, PAT protein of genetically modified maize was prepared from the recombinant E. coli strain BL21 (DE3), and mice were immunized with the recombinant PAT protein. After cell fusion and cloning, two hybridoma cells (PATmAb-7 and PATmAb-12) were chosen since the monoclonal antibodies (Mabs) produced by them were confirmed to be specific to PAT protein in the indirect enzyme-linked immunsorbent assay (ELISA) and western blot tests. There were no cross-reactions of either Mabs to other GM proteins or to the extracts of non-GM maize. The ELISA based on the PATmAb-7 can sensitively detect 0.3 ng/g PAT protein in corn. These results indicate that the developed Mabs can be used as bio-receptors in the development of immunosensors and biosensors for the rapid and simple detection of GM corn adulterated in foods.

• Journal of the Korean GEO-environmental Society
• /
• v.13 no.10
• /
• pp.25-32
• /
• 2012

The application of electrical resistivity, which is related to charge mobility, has increased in the field of geotechnical engineering for the detection of underground cavern, faults and subsurface pollution level. The purpose of this study is to investigate the variation of electrical resistivity due to temperature change. Sand-silt mixture specimens prepared in the square freezing nylon cell are frozen in the frozen chamber. Four electrodes are attached on the four side walls of the freezing cell for the measurement of electrical resistance during temperature change. Electrical resistances of sand-silt mixtures with different degrees of saturation (0%, 2.5%, 5%, 10%, 20%, 40%, 60% and 100%) are measured as the temperature of specimens decrease from $20^{\circ}C$ to $-10^{\circ}C$. The electrical resistances determined by Ohm's law are transformed into the electrical resistivity by calibration. Experimental results show that the higher degree of saturation, the lower electrical resistivity at $20^{\circ}C$. Electrical resistivity gradually increases as the temperature decrease from $20^{\circ}C$ to $0^{\circ}C$. For the specimens with the degree of saturation of 15% or higer, electrical resistivity dramatically changes near the temperature of $0^{\circ}C$. In addition, very high electrical resistivity is observed regardless of the degree of saturation if the specimens are frozen. This study provides the fundamental information of electrical resistivity according to the soil freezing and temperature change demonstrates that electrical resistivity be a practical method for frozen soil investigation.

• Tuberculosis and Respiratory Diseases
• /
• v.55 no.5
• /
• pp.440-448
• /
• 2003

Background : Development of rapid drug susceptibility testing provides the opportunity for rapid identification of individuals with drug resistant tubercle bacilli, allowing selection of appropriate therapeutic regimens. Methods : A total of 502 drug resistant isolates were subjected to reverse blot hybridization assay to detect mutations within genes (rpoB, katG, inhA, and ahpC) associated with rifampicin (RMP) and isoniazid (INH) resistance. Results : Among the 264 RMP resistant strains ($RMP^R$) tested, the most prevalent mutation was the Ser531Leu seen in 121 strains (46%). The second common mutation occurred in 84 strains (32%) at codon 526. And 27 strains (10%) showed the mutation at codon 516. Among all 469 INH resistant strains ($INH^R$), the katG mutation was responsible for INH. The inhA mutation was present in 88 strains (19%). In 11 isolates (2%), coexisting of the katG and inhA mutations were identified. Reverse hybridization assay successfully detected over 80% of $INH^R$ and over 92% of $RMP^R$ among Korean isolates. CONCLUSION: Reverse hybridization was useful for rapid detection of $INH^R$ and $RMP^R$.

• Korean Journal of Poultry Science
• /
• v.40 no.3
• /
• pp.223-234
• /
• 2013

Poultry industry is abounding day by day as it engrosses less cost of investment per bird as compared to large animals. Poultry have the most copious genomic tool box amongst domestic animals for the detection of quantitative trait loci (QTL) and marker assisted selection (MAS). Use of multiple markers and least square techniques for mapping of QTL affecting quality and production traits in poultry is in vogue. Examples of genetic tests that are available to or used in industry programs are documented and classified into causative mutations (direct markers), linked markers in population-wide linkage disequilibrium (LD) with the QTL (LD markers), and linked markers in population wide equilibrium with the QTL (LE markers). Development of genome-wide SNP assays, role of 42 K, 60 K (Illumina) and 600 K (Affymetrix$^{(R)}$ Axim$^{(R)}$) SNP chip with next generation sequencing for identification of single nucleotide polymorphism (SNP) has been documented. Hybridization based, PCR based, DNA chip and sequencing based are the major segments of DNA markers which help in conducting of MAS in poultry. Economic index-marker assisted selection (EI-MAS) provides platform for simultaneous selection for production traits while giving due weightage to their marginal economic values by calculating predicted breeding value, using information on DNA markers which are normally associated with relevant QTL. Understanding of linkage equilibrium, linkage dis-equilibrium, relation between the markers and gene of interest are quite important for success of MAS. This kind of selection is the most useful tool in enhancing disease resistance by identifying candidate genes to improve the immune response. The application of marker assisted selection in selection procedures would help in improvement of economic traits in poultry.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.46 no.4
• /
• pp.124-131
• /
• 2009

A reliable detection of regions in radiography is one of the most important task before the evaluation of defects on welded joints. The extracted features is to be classified into distinctive clusters for each segmented region. But conventional segmentation techniques give unsatisfactory results for this task due to the spatial superposition of intensity and low signal-to-ratio(SNR) in radiographic images. The usage of global or local processes not only provide the necessary noise resistance but also fail in classification of regions. In this paper, we presents an appropriate approach for segmentation of region-based indications in industrial Computed Radiography(CR) images. The geometric differences between welded and non-welded area which is generated on radiography as the representative regions(background, thickness, middle and welded region in steel tube image) have constructed the hierarchical structure. Although this structure is contaminated by noise, the scheme between regions can be selected by the help of local clustering based on distinctive geometric property of each region. Because of the geometric nature of the considered region and so that the region is selected layer by layer, and that the real class represents the boundary between regions, the vertical and horizontal clustering process in each layer must be judicious. In order to show the effectiveness of this approach, a comparative experiment of various segmentation method is performed on industrial steel tube CR images.

• Polymer(Korea)
• /
• v.36 no.4
• /
• pp.486-493
• /
• 2012

Photocurable sulfonated polyimide (SPI) polyelectrolyte containing chalcone group was prepared and fabricated on an alumina electrode pretreated with chalcone-containing silane-coupling agent. SPI films with bis(tetramethyl)ammonium 2,2'-benzidinedisulfonate ($Me_4N$-BDS)/4,4'-diaminochalcone (DAC)/pyromellitic dianhydride (PA)= 90/10/100 possessed very linear response(Y = -0.04528X+7.69446, $R^2=0.99675$) and showed resistance changing from 4.48 to $2.1k{\Omega}$ between 20 and 95 %RH. The response time for absorption and desorption measurements between 33 and 94 %RH% was about 79 s, which affirmed the high efficiency of crosslinked SPI film for rapid detection of humidity. A negative temperature coefficient showing $-0.49%RH/^{\circ}C$ was found and proper temperature compensation should be considered in future applications. Moreover, pretreatment of the substrates with chalcone-containing silane-coupling agent was performed to improve the water durability and the stability of the humidity sensors at a high humidity and a high temperature and long-term stability for 480 h. The crosslinked SPI films anchored to electrode substrate could be a promising material for the fabrication of efficient humidity sensors with superior characteristics compared to the commercially available sensors.

• Korean Journal of Microbiology
• /
• v.44 no.4
• /
• pp.305-310
• /
• 2008

Staphylococcus aureus is one of the most significant pathogens and a causative agents of nosocomial infections. The emergence of methicillin resistant S. aureus (MRSA), in particular, has become a major clinical and epidemiological problems worldwide. In this study, we analyzed the toxin genes and investigated molecular epidemiological characteristics of S. aureus isolated from stools of diarrheal patients at the hospitals in Incheon. Of the 609 strains from 2,281 specimens, 173 strains retained enterotoxin; 68 isolates (39.30%), 100 isolates (57.80%) were classified to A and C type, respectively. In the antibiotic susceptibility, all of enterotoxin positive isolates were resistant to oxacillin. Eighty eight strains (50.86%) of 173 MRSA isolate possessed tsst gene, but eta and eth genes were not detected at all. In the detection of MRSA associated genes by PCR method, mecA genes were detected in 167 strains (96.53%). From the result of PFGE analysis, we classified tsst-positive MRSA to 10 types and 24 subtypes. Type A, H and F were the major strains comprised of 57.95% (51 strains), 10.22% (9 strains) and 9.09% (8 strains) respectively.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2006.05a
• /
• pp.1023-1026
• /
• 2006

There are some cases in trouble with monitoring emergency patient by existing electrode sensor in measuring instrument in home and hospital etc. And there are problem to measure because of coming down electrode in emergency car or vessel of shaking and fat, humidity of patient. In this study, it has designed band-type for patient to put on the breast easily and go around anywhere freely putting band electrode on his body. Gold has used as electrode material in this electrocardiogram because of its excellent electronic resistance peculiarity and no trouble with skin. And it is able to monitor multi-body-signal by additional design of periphery temperature. There are good results of body signal transmission in the breast or the rib, and get a little body signal in abdomen. We get a result it is better case of gold than usual electrode on signal detection, and know usual electrode was disposable, but we have more correct result from gold electrode sensor, being semi-permanent ana. great contact ability even if movement.

• Nuclear Engineering and Technology
• /
• v.45 no.4
• /
• pp.513-522
• /
• 2013

The ODSCC detected in the TSP position of Ulchin 3&4 SGs are typical ODSCC of Alloy 600MA tubes. The causative chemical environment is formed by concentration of impurities inside the occluded region formed by the tube surface, egg crate strips, and sludge deposit there. Most cracks are detected at or near the line contacts between the tube surface and the egg crate strips. The region of dense crack population, as defined as between $4^{th}$ and $9^{th}$ TSPs, and near the center of hot leg hemisphere plane, coincided well with the region of preferential sludge deposition as defined by thermal hydraulics calculation using SGAP computer code. The cracks developed homogeneously in a wide range of SGs, so that the number of cracks detected each outage increased very rapidly since the first detection in the $8^{th}$ refueling outage. The root cause assessment focused on investigation of the difference in microstructure and manufacturing residual stress in order to reveal the cause of different susceptibilities to ODSCC among identical six units. The manufacturing residual stress as measured by XRD on OD surface and by split tube method indicated that the high residual stress of Alloy 600MA tube played a critical role in developing ODSCC. The level of residual stress showed substantial variations among the six units depending on details of straightening and OD grinding processes. Youngwang 3&4 tubes are less susceptible to ODSCC than U3 and U4 tubes because semi-continuous coarse chromium carbides are formed along the grain boundary of Y3&4 tubes, while there are finer less continuous chromium carbides in U3 and U4. The different carbide morphology is caused by the difference in cooling rate after mill anneal. There is a possibility that high chromium content in the Y3&4 tubes, still within the allowable range of Alloy 600, has made some contribution to the improved resistance to ODSCC. It is anticipated that ODSCC in Y5&6 SGs will be retarded more considerably than U3 SGs since the manufacturing residual stress in Y5&6 tubes is substantially lower than in U3 tubes, while the microstructure is similar with each other.