• 제목/요약/키워드: SI technique

Search Result 1,431, Processing Time 0.052 seconds

Quantitative Approaches for the Determination of Volatile Organic Compounds (VOC) and Its Performance Assessment in Terms of Solvent Types and the Related Matrix Effects

  • Ullah, Md. Ahsan;Kim, Ki-Hyun;Szulejko, Jan E.;Choi, Dal Woong
    • Asian Journal of Atmospheric Environment
    • /
    • v.11 no.1
    • /
    • pp.1-14
    • /
    • 2017
  • For the quantitative analysis of volatile organic compounds (VOC), the use of a proper solvent is crucial to reduce the chance of biased results or effect of interference either in direct analysis by a gas chromatograph (GC) or with thermal desorption analysis due to matrix effects, e.g., the existence of a broad solvent peak tailing that overlaps early eluters. In this work, the relative performance of different solvents has been evaluated using standards containing 19 VOCs in three different solvents (methanol, pentane, and hexane). Comparison of the response factor of the detected VOCs confirms their means for methanol and hexane higher than that of pentane by 84% and 27%, respectively. In light of the solvent vapor pressure at the initial GC column temperature ($35^{\circ}C$), the enhanced sensitivity in methanol suggests the potential role of solvent vapor expansion in the hot injector (split ON) which leads to solvent trapping on the column. In contrast, if the recurrent relationships between homologues were evaluated using an effective carbon number (ECN) additivity approach, the comparability assessed in terms of percent difference improved on the order of methanol (26.5%), hexane (6.73%), and pentane (5.24%). As such, the relative performance of GC can be affected considerably in the direct injection-based analysis of VOC due to the selection of solvent.

Effect of Ankle Joint Mobilization and FES on Change of Ankle Movement and the Quality of Gait in Patients with Hemiplegia

  • Lee, Hyun Suk;Park, Si Eun;Lee, Sang Bin;Kim, Bo Kyoung;Shin, Hee Joon;Kim, Hong Rae;Choi, Young Duk;Min, Kyung Ok
    • Journal of International Academy of Physical Therapy Research
    • /
    • v.5 no.2
    • /
    • pp.738-742
    • /
    • 2014
  • This study was conducted to investigate the effect of FES and ankle mobilization on the ankle motion and the quality of gait of chronic hemiplegic patients with limited ankle joint motions. As research subjects, 24 chronic hemiplegic patients who could walk independently, regardless of assistive aids, were selected. Then, 8 subjects received mobilization randomly and 8 subjects received FES and 8 subjects received mobilization and FES, at the same time. The dorsiflexion PROM significantly increased in the group of mobilization therapy, mobilization and FES all together(p<.01). There were statistically significant differences among the three groups(p<.01). The 10m walking test significantly decreased in the group of mobilization therapy, mobilization and FES all together(p<.05). There were statistically significant differences among the three groups(p<.01). The gait velocity significantly increased in the group of mobilization therapy, FES therapy, mobilization and FES all together(p<.05). There were statistically significant differences among the three groups(p<.01). The stride length significantly increased in the group of mobilization therapy, mobilization and FES all together(p<.05). There were statistically significant differences among the three groups(p<.05). In conclusion, these findings demonstrate that rather than only using one treatment technique, applying mobilization and FES together brings a more satisfactory result to hemiplegic patients with limited ankle joint motions.

Versatility of the Distally-Based Sural Artery Fasciocutaneous Flap on the Lower Leg and Foot in Patients with Chronic Disease

  • Park, Jin-Su;Roh, Si-Gyun;Lee, Nae-Ho;Yang, Kyoung-Moo
    • Archives of Plastic Surgery
    • /
    • v.40 no.3
    • /
    • pp.220-225
    • /
    • 2013
  • Background A recent advancement in microsurgery, the free flap is widely used in the reconstruction of the lower leg and foot. The simple and effective methods of local flaps, including transposition and advancement flaps, have been considered for patients with chronic debilitation who are unable to endure long surgical procedures or general anesthesia. However, the location and size of the wound may restrict the clinical application of a local flap. Under these circumstances, a sural flap can be an excellent alternative, rendering satisfying clinical outcomes in chronically debilitated patients. Methods Between 2008 and 2012, 39 patients underwent soft tissue defect treatment by sural artery flap as a final method. All of the patients had at least one chronic disease or more (diabetes, hypertension, vascular disease, etc.). Also, all of the patients had a history of chronic lower extremity ulceration, which revealed no response to several months of conservative treatment. Results The results of the 39 cases had a success rate of 100% with 39 complete recoveries. Nine cases suffered complications: partial necrosis (n=4), wound dehiscence without necrosis (n=3), hematoma (n=1), and infection (n=1). Conclusions The sural artery flap is not only useful for the lower leg but also for the heel, and other various parts. Furthermore, it is a relatively simple surgical technique for reconstructing the defect area for patients with various chronic conditions with a high surgical risk or contraindications to surgery.

Increase of Side-lobe Level Difference of Spherical Microphone Array by Implementing MEMS Sensor

  • Lee, Jae-Hyung;Choi, Si-Hong;Choi, Jong-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2011.04a
    • /
    • pp.816-820
    • /
    • 2011
  • A method for increasing the difference of side-lobe level in spherical microphone array is presented. In array signal processing, it is known that narrow interval between sensors can increase the difference between main lobe and side-lobe of array response which eventually increase the source recognition capability. Recent commercial array being used, however, have shown certain limitation in using the number of sensors due to its costs and geometrical size of array. To overcome this problem, we have adapted MEMS sensors into spherical microphone array. To check out the improvement, two different types of spherical microphone array were designed. One array is composed with 32 regular instrument microphones and the other one is 85 MEMS sensors. Simulation and experiments were conducted on a sinusoidal noise source with two arrays. The time history data were analyzed with spherical harmonic decomposition and beamforming technique. 85 MEMS sensors array showed the improved side-lobe level suppression by more than 4 dB above the frequency content of 2 kHz compared to 32-sensor array.

  • PDF

Study on Deficiency-Excess Pattern Questionnaire Development Possibility (허실 변증 설문지 개발 가능성에 대한 고찰)

  • Ryu, Hyun-Hee;Lee, Hae-Jung;Jang, Eun-Su;Lee, Si-Woo;Lee, Gi-Sang;Kim, Jong-Yeol
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.23 no.3
    • /
    • pp.534-539
    • /
    • 2009
  • Deficiency and excess pattern differentiation is unique characteristic of traditional oriental medicine on diagnosis and treatment. This differentiation is accomplished through pulse, tongue diagnosis and question examination, but most of these processes need to be objectified for efficacious treatment and traditional medicine development. In this study, we developed the deficiency and excess pattern questionnaire for objectification of question examination. The deficiency and excess pattern questionnaire was made out through The Traditional Oriental Medical Literature with Delphi Technique. Patients who visited oriental medical hospital filled out the questionnaire by themselves. Diagnosis of deficiency and excess pattern are conducted separately by oriental medical doctors with more than 5 years' clinical experience. Various physical condition factors were derived for the deficiency and excess pattern questionnaire. (Ordinary health degree, pain pattern, fatigue, weight change, sweating, uncomfortable awareness on chest and abdomen) Deficiency symptoms group acquired internal consistency, but excess symptoms group did not. (Cronbach's ${\alpha}$ > 0.6) There were significant associations between doctor's diagnosis and deficiency and excess symptoms in 'ordinary heath degree', 'voice weakening', and 'chest distress' (p-value < 0.1) There were significant differences between deficiency and excess syndrome patients groups in deficiency questionnaire score but there were no significant differences between deficiency and excess syndrome patients groups in excess questionnaire score. We acquired the internal consistency and significant result of deficiency pattern questionnaire, but we can find out some difficulties in development of the excess pattern questionnaire. These difficulties are associated with insufficiency description of traditional literature and small number of patients diagnosed as excess pattern.

The epigenetic phenotypes in transgenic Nicotiana benthamiana for CaMV 35S-GFP are mediated by spontaneous transgene silencing

  • Sohn, Seong-Han;Choi, Min-Sue;Kim, Kook-Hyung;Lomonossoff, George
    • Plant Biotechnology Reports
    • /
    • v.5 no.3
    • /
    • pp.273-281
    • /
    • 2011
  • Diverse epigenetic phenotypes are frequently found during research on transgenic plants. To understand the factors underlying such diversity, hundreds of independent 35S-GFP transgenic N. benthamiana plants were analyzed. The diverse GFP-expression phenotypes of the transgenic plants were classified into three major types based on the GFP expression patterns and their response to 35S-GFP agroinfiltration: steady-green, silenced and non-uniform phenotype. The non-uniform phenotype was further sub-divided into five minor phenotypes: variegated, red-dropped, on-silencing, partitioned and misty, according to the distribution of GFP expression on the leaves. Many of transgenic plants continuously generated diverse phenotypes over several generations despite the transgene identity. Such epigenetic GFP phenotyping was found to be the result of spontaneous transgene silencing mediated by either or both of post-transcriptional gene silencing (PTGS) and transcriptional gene silencing (TGS). This finding was verified by the detection of 21- and 24-nt small interfering RNA (siRNA) molecules, and DNA methylation in the transgenic plants that showed repeated epigenetic variation. Agroinfiltration demonstrated that irregular distribution of GFP on a leaf was the result of erratic transgene silencing, and the technique also proved to be a rapid and effective method for selecting fully silenced plants within 3 days. Furthermore, two novel phenotypes described are potential materials for in-depth investigations into the genes and mechanisms responsible for spontaneous transgene silencing.

The electronic structure of the ion-beam-mixed Pt-Cu alloys by XPS and XANES

  • Lim, K.Y.;Lee, Y.S.;Chung, Y.D.;Lee, K.M.;Jeon, Y.;Whang, C.N.
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 1998.02a
    • /
    • pp.133-133
    • /
    • 1998
  • In the thin film alloy formation of the transition metals ion-beam-mixing technique forms a metastable structure which cannot be found in the arc-melted metal alloys. Sppecifically it is well known that the studies about the electronic structure of ion-beam-mixed alloys pprovide the useful information in understanding the metastable structures in the metal alloy. We studied the electronic change in the ion-beam-mixed ppt-Ct alloys by XppS and XANES. These analysis tools pprovide us information about the charge transfer in the valence band of intermetallic bonding. The multi-layered films were depposited on the SiO2 substrate by the sequential electron beam evapporation at a ppressure of less than 5$\times$10-7 Torr. These compprise of 4 ppairs of ppt and Cu layers where thicknesses of each layer were varied in order to change the alloy compposition. Ion-beam-mixing pprocess was carried out with 80 keV Ae+ ions with a dose of $1.5\times$ 1016 Ar+/cm2 at room tempperature. The core and valence level energy shift in these system were investigated by x-ray pphotoelectron sppectroscoppy(XppS) pphotoelectrons were excited by monochromatized Al K a(1486.6 eV) The ppass energy of the hemisppherical analyzer was 23.5 eV. Core-level binding energies were calibrated with the Fermi level edge. ppt L3-edge and Cu K-edge XANES sppectra were measured with the flourescence mode detector at the 3C1 beam line of the ppLS (ppohang light source). By using the change of White line(WL) area of the each metal sites and the core level shift we can obtain the information about the electrons pparticippating in the intermetallic bonding of the ion-beam-mixed alloys.

  • PDF

Correlation between terahertz characteristics and defect states in LTG-InGaAs

  • Park, Dong-U;Kim, Jun-O;Lee, Sang-Jun;Kim, Chang-Su;Lee, Dae-Su;No, Sam-Gyu;Gang, Cheol;Gi, Cheol-Sik;Kim, Jin-Su
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2010.08a
    • /
    • pp.243-243
    • /
    • 2010
  • Low-temperature grown (LTG) InGaAs epilayers were grown by MBE technique for studying a correlation between terahertz (THz) emission and the intrinsic defects. The 1.2-um-thick Be-compensated LTG-InGaAs epilayers were prepared on SI-InP:Fe substrate at $200-250^{\circ}C$, and subsequently in-situ annealed under As environment at $550^{\circ}C$ for 5-30 minutes. The carrier concentration/mobility and the crystalline structure were analyzed by the Hall effect and the x-ray diffraction (XRD), respectively, and the carrier lifetime were determined by the fs time-resolved pump-probe spectroscopy. THz generation from LTG-InGaAs was carried out by a Ti-sapphire laser (800 nm) of a pulse width of 190 fs at a repetition of 76 MHz. Figure shows the spectral amplitude of generated waves in the THz region. As the growth temperature of epilayer increases, the amplitude is enhanced. However, two samples grown at $200^{\circ}C$, as-grown and annealed, show almost no difference in the spectral amplitude. This suggests that the growth temperature is critical in the formation of defect states involved in THz emission. We are now investigating the correlations between the XRD band attributed to defects, the Hall parameter, and the spectral amplitude of generated THz wave.

  • PDF

Infection Status of Freshwater Fish with Metacercariae of Clonorchis sinensis in Korea

  • Kim, Eun-Min;Kim, Jae-Lip;Choi, Sung-Yil;Kim, Jae-Whan;Kim, Si-Won;Choi, Min-Ho;Bae, Young-Mee;Lee, Soon-Hyung;Hong, Sung-Tae
    • Parasites, Hosts and Diseases
    • /
    • v.46 no.4
    • /
    • pp.247-251
    • /
    • 2008
  • This study investigated freshwater fish for their current infection status with metacercariae of Clonorchis sinensis in Korea. Twenty-one species of freshwater fish (n = 677) were collected from 34 regions nationwidely from February 2007 to June 2008. They were individually examined by digestion technique. Eight species of freshwater fish from 17 different regions were recognized positive for the metacercariae of C. sinensis. The positive rates (range of metacercariae number per fish) of fish by the species were as follows: 48% (1-1,142) in Pseudorasbora parva, 60% (1-412) in Pungtungia herzi, 15.7% (1-23) in Pseudogobio esocinus, 29% (1-7) in Acheilognathus intermedia, 21% (1-4) in Odontobutis interrupta, 33% (1-6) in Zacco temmincki, 3.6% (1-4) in Zacco platypus, and 26.3% (1) in Hemibarbus labeo. The two species, P. parva and P. herzi, are able to be the index fish for estimation of C. sinensis transmission in a certain locality. Still several species of freshwater fish are briskly transmitting C. sinensis infection in many riverside areas of southern Korea.

Effects of Color Pigments on the Hanji Deterioration (체색용 안료가 한지의 열화에 미치는 영향)

  • Nam, Hyun-Ju;Cho, Kyoung-Sil;Choi, Tae-Ho
    • Journal of Korea Technical Association of The Pulp and Paper Industry
    • /
    • v.47 no.2
    • /
    • pp.70-79
    • /
    • 2015
  • This study was carried out to analyze deterioration characteristics of color-pigments painted Hanji to preserve and restore the cultural properties. On the traditional painting technique, glue was used with pigments in various ways for painting, but it eventually caused the deterioration of paintings. Thus, five colors were selected and analyzed for this study for investigating their characteristics of deteriration. Three kinds of glues (Wugyo, Nokgyo, and Togyo) and two kinds of pigments (Chinese and Gilsang) were painted on the Hanji for the accelerated aging test. And then color fastness of pigments and tensile strength of painted Hanji were measured for the estimation of deterioration degree. The results of SEM-EDS showed that Chinese pigments including blue, yellow, green, and red were composed of inorganic substances but the brown was organic substance. Gilsang pigments were composed mainly of Si and Ti ions. Color fastness of the Gilsang pigment blue, yellow, green, and brown were better than those of Chinese. Chinese pigment brown with organic substance showed the worst color fastness. Generally, Chinese pigments painted Hanji showed higher tensile strength than Gilsang in the accelerated aging test. Hanji treated with Chinese pigment and Nokgyo (antler glue) blends and Gilsang pigment and Togyo (rabbit pelt glue) blends showed higher tensile strength than the others. And Andong Hanji showed the highest tensile strength.