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Two-dimensional (2D) metal oxide nanosheets have been synthesized through ion exchange reactions. However, they require a long time and lead to low production yields due to the molecular size of the intercalant and reaction activation energies. To reduce the processing time and accelerate the production yield, we introduce an ultrasonically supported ion exchange reaction process. We applied ultrasound energy on the solution of RuO2 nanosheets and the intercalant after 3 days of stirring the ion exchange reaction. After 15 min, the yield of RuO2 nanosheets increased by over 50%. In addition, we observed that the lateral size of the RuO2 nanosheets decreased with the applied ultrasonic time. Density functional theory calculations demonstrated that the activation energy of exfoliation is significantly reduced by splitting the RuO2 layers into a small lateral size. This result shows that ultrasound provides energy for 15 min of exfoliation of the RuO2 nanosheets, after which the energy is used to break the RuO2 nanosheets. The experimental and theoretical results suggest that an ultrasonic-supported ion exchange process offers a facile and efficient approach for fabricating 2D metal oxide nanosheets.

High levels of E. coli and associated faecal microbes in waterways as a result of agricultural and residential land use can pose environmental, human health, and economic risks. This study aims to understand the impacts of land use, climatic variables, and riparian buffers on in-stream E. coli concentrations. Flow, temperature, and E. coli were monitored during three sampling campaigns within eleven independent catchments. These catchments have varying land use and extents of riparian buffer coverage. Results showed that catchments with predominantly agricultural and residential land uses (average = 349.7 MPN/100 mL) had higher E. coli concentrations than predominantly forested catchments (average = 111.8 MPN/100 mL). However, there were no statistically significant differences in E. coli concentrations between the agricultural and residential land uses. Riparian buffers appear to reduce E. coli concentrations in streams, as indicated by significant negative correlations between in-stream E. coli concentrations with the riparian buffer areal coverage (Pearson's r = -0.95, Spearman's ρ = -0.90) and the ratio of buffer length to stream length (Pearson's r = -0.87, Spearman's ρ = -0.90). We find that riparian buffers potentially disrupt transport pathways that govern E. coli movement, which in-turn can affect the concentration-discharge relationship. This reinforces the importance of protecting and restoring riparian buffers along drainage lines in agricultural and rural-residential catchments to improve downstream microbial water quality.

Supplemental material, sj-pdf-1-jdr-10.1177_0022034521999298 for Retroductal Delivery of Epidermal Growth Factor Protects Salivary Progenitors after Irradiation by J.M. Cho, Y.J. Yoon, S. Lee, D. Kim, D. Choi, J. Kim and J.Y. Lim in Journal of Dental Research

ZnO is utilized as a promising material for various electronic and energy areas due to its outstanding chemical stability, abundance, non-toxicity, and low cost. However, controlling electronic transport properties of ZnO by facile strategy is still necessary for wider applications. Here, we synthesized reduced graphene oxide incorporated Al-doped ZnO nanocomposite thin film prepared by the electrospray deposition method and investigated the electronic transport behavior. The electron transport in pristine Al-doped ZnO thin film is strongly affected by grain boundary scattering, but significant enhancement of carrier mobility is observed in reduced graphene oxide-incorporated Al-doped ZnO nanocomposite thin film. The results demonstrate that this hybrid strategy with graphene has an important effect on the charge transport behavior in ZnO polycrystalline materials.

Various cheese products are involved in outbreaks of listeriosis worldwide due to high consumption and prolonged refrigerated storage. The objective of this study was to determine the efficacy of using lactic acid bacteria and packaging with grapefruit seed extract (GSE) for controlling Listeria monocytogenes growth in soft cheese. Leuconostoc mesenteroides and Lactobacillus curvatus isolated from kimchi were used as a starter culture to make a soft cheese, which was inoculated with a cocktail strain of L. monocytogenes. The soft cheese was packed with low-density polyethylene, biodegradable polybutylene adipate-co-terephthalate (PBAT), low-density polyethylene with GSE, or PBAT with GSE and stored at 10°C and 15°C. Leuconostoc mesenteroides (LcM) better inhibited the growth of L. monocytogenes than Lb. curvatus. The PBAT with GSE film showed the best control for the growth of L. monocytogenes. When both LcM and PBAT with GSE were applied to the soft cheese, the growth of L. monocytogenes was inhibited significantly more than the use of LcM or PBAT with GSE alone. In all test groups, water activity, pH, and moisture on a fat-free basis decreased, and titratable acidity increased compared with the control group. These results suggest that LcM isolated from kimchi and PBAT with GSE packaging film can be used as a hurdle technology to lower the risk of L. monocytogenes in soft cheese at the retail market.

The giant clam, Tridacna squamosa, represents a clam-zooxanthellae association. In light, the host clam and the symbiotic zooxanthellae conduct light-enhanced calcification and photosynthesis, respectively. We had cloned the cDNA coding sequence of a Vacuolar-type Proton ATPase (VHA) subunit A, ATP6V1A, from T. squamosa, whereby the VHA is an electrogenic transporter that actively ‘pumps’ H+ out of the cell. The ATP6V1A of T. squamosa comprised 1866 bp, encoding a protein of 622 amino acids and 69.9 kDa, and had a host-origin. Its gene expression was strong in the ctenidium and the colorful outer mantle, but weak in the whitish inner mantle, corroborating a previous proposition that VHA might have a trivial role in light-enhanced calcification. Light exposure led to significant increases in the gene and protein expression levels of ATP6V1A/ATP6V1A in the ctenidium and the outer mantle. In the ctenidium, the ATP6V1A was localized in the apical epithelia of the filaments and tertiary water channels, indicating that the VHA could participate in the increased excretion of H+ produced during light-enhanced calcification. Additionally, the excreted H+ would augment HCO3– dehydration in the external medium and facilitate the uptake of CO2 by the ctenidium during insolation. In the outer mantle, the ATP6V1A was detected in intracellular vesicles in a type of cells, presumably iridocytes, surrounding the zooxanthellal tubules, and in the apical epithelium of zooxanthellal tubules. Hence, the host VHA could participate in the transfer of inorganic carbon from the hemolymph to the luminal fluid of the tubules by increasing the supply of H+ for the dehydration of HCO3– to CO2 during insolation to benefit the photosynthesizing zooxanthellae.

Purpose This study aimed to evaluate the safety and effectiveness of interventional techniques as a treatment for bleeding complications secondary to percutaneous cannulation for peripheral extracorporeal membrane oxygenation (PECMO). Materials and methods Out of 1264 patients who underwent PECMO at our hospital between January 2009 and September 2018, we reviewed the clinical characteristics and outcomes of eight patients (4 men, 4 women; mean age, 54.9 years [range, 31–77 years]) who underwent percutaneous interventional treatment for bleeding complications secondary to percutaneous cannulation for PECMO. Results Both hemodynamic instability and coagulopathy were present in 7 patients who had direct injury during PECMO insertion and absent in one patient with pseudoaneurysm at the PECMO removal site. Percutaneous ultrasound-guided thrombin injection was performed in three patients with pseudoaneurysm of the common or superficial femoral artery, and adjunctive embolization was combined with microcoils or n-butyl 2-cyanoacrylate in two of them. Stent graft was inserted in four patients with contrast extravasation (n = 3) from external iliac artery (n = 1) or common femoral or iliac veins (n = 2) ruptures or the fistula between the superficial femoral artery and vein (n = 1). N-butyl 2-cyanoacrylate and coil embolization was performed for pseudoaneurysm from the internal pudendal artery branch in the remaining one patient. Technical success was achieved in all eight patients. There were no procedure-related complications. There was no rebleeding during the follow-up. Conclusion Interventional treatment is a safe, technically feasible and therapeutically effective modality for treating bleeding complications secondary to a percutaneous cannulation for PECMO.

Amorphous Mg-based bulk metallic glasses (BMGs) are relatively new materials for various engineering applications because of their superior mechanical properties and corrosion resistance. Recently, BMGs attract significant attention as a new class of biodegradable materials. Some of their properties have been observed to be superior as compared to their crystalline counterparts. The current state of the art of Mg-based BMGs development for biomedical implant applications is still focused on the glass forming ability and their formation mechanism. Some types of Mg-based BMGs demonstrate very encouraging results in terms of biodegradability and biocompatibility performances. However, there are still many Mg-based BMGs in development stage where toxic alloying elements are used. This study reviews the characteristics and role of elements with good glass forming ability toward development of Mg-based bulk metallic glasses. It discusses the glass forming ability, mechanical properties, corrosion behavior, and biocompatibility of previously reported Mg-based BMGs. It ends with the proposed strategy for future development of Mg-based BMGs for biodegradable implant utilization.

The Korea Research Institute of Standards and Science (KRISS) has three major vacuum systems: an ultrasonic interferometer manometer (UIM; Section II, Figs. 1 and 2) for a low vacuum, a static expansion system (SES; Section III, Figs. 3 and 4) for a medium vacuum, and an orifice-type dynamic expansion system (DES, Section IV, Figs. 5 and 6) for high and ultra-high vacuum systems. For each system, explicit measurement model equations with multiple variables are given. According to ISO standards, all of these system variable errors were used to calculate the expanded uncertainty (U). For each system, the expanded uncertainties (k = 1, confidence level = 95%) and relative expanded uncertainty (expanded uncertainty/generated pressure) levels are summarized in Table 4. Within the uncertainty limits, our bilateral and key comparisons [CCM.P-K4 (10 Pa to 1 kPa)] are extensive and in good agreement with those of other nations (Fig. 8 and Table 5).

Syncytiotrophoblast microvesicles (STBM) are shed from placenta into the maternal circulation. STBM circulate in increased amounts in adverse pregnancies, e.g., preeclampsia and recurrent miscarriages (RM). Recently dysregulation of lipid metabolites has been proposed to be associated with their pathogenesis. Lipid composition of STBM in healthy and adverse pregnancies remains unknown.To determine lipid composition of STBM and whether STBM lipid composition differs in pathologic and normal pregnancies.Patients with Preeclampsia (n = 6) or history of RM (n = 9) (2 consecutive losses20 weeks) and gestational age-matched normal pregnant controls (same number as cases) were recruited. STBM were prepared from placental explant culture supernatant. Lipid profiling of STBM was performed by mass spectrometry in combination with liquid chromatography. We quantified ∼200 lipids in STBM including (i) glycerophospholipids (phosphatidylcholine, PC; phosphatidylethanolamine, PE; phosphatidylinositol, PI; phosphatidylglycerol, PG; phosphatidylserine, PS; phosphatidic acid, PA); (ii) sphingolipids (sphingomyelin, SM; ceramide, Cer; Glucosylceramide, GluCer; ganglioside mannoside 3, GM3); (iii) free cholesterol and cholesteryl esters, CE.The major lipid classes in STBM were SM, Chol, PS, PC and PI, along with PA and GM3 enrichments. SM/PC ratio showed a unique reversal (3:1) compared to that normally found in human cells or plasma. Level of total PS was significantly upregulated (p0.005) in preeclampsia patients, while PI (p0.0005), PA (p0.005), and GM3 (p0.05) were significantly downregulated. Similar trends were obtained in RM.Differential lipid expression of STBM in preeclampsia or RM includes those that are implicated in immune response, coagulation, oxidative stress, and apoptosis.

The measurement device of internal pressures of small components sealed hermetically was developed. The internal pressure of a sample measured with this device was 43.151 kPa, and the expanded uncertainty (

The Korea Research Institute of Standards and Science (KRISS) has three major vacuum systems: an ultrasonic interferometer manometer (UIM), a static volume expansion system (SVES), and an orifice-type dynamic expansion system (ODES). For each system explict measurement model equations with multiple variables are respectively given. According to ISO standards, all these system variables errors were used to calculate the expanded uncertainty (U).

The main objective of this study is to examine the sensitivity of calibration curves of FEA of ring compression test to frictional shear factor. Ring compression test has been investigated by measuring dimensional changes at different positions of ring specimen and they include the changes in internal diameter at the middle and top section of the specimen, outer diameter at the middle and top section, surface expansion at the top surface, respectively. Initial ring geometries employed in analysis maintain a fixed ratio of 6 : 3 : 2, i.e. outer diameter : inner diameter : thickness of the ring specimen, which is generally known as ‘standard’ specimen. A rigid plastic material for different work-hardening characteristics has been modeled for simulations using rigid-plastic finite element code. Analyses have been performed within a definite range of friction as well as over whole range of friction to show different sensitivities to the interfacial friction for different ranges of friction. The results of investigation in this study have been summarized in terms of a dimensionless gradient. It has been known from the results that the dimensional changes at different positions of ring specimen show different linearity and sensitivity to the frictional condition on the contact surface.

Pressure vacuum measurement technique using acoustic impedance change of ultrasonic transducers was studied. The sensor has been setup using two air-coupled ultrasonic transducers, one as a transmitter and the other as a receiver, and put it into vacuum chamber and measured pressure versus ultrasonic amplitude. The result confirms that the standard deviations of four repeat measurements were from 0.0093 to 0.3325 at pressure 6.66 kPa to 202.65 kPa(about two atmosphere), and the relative percents were 0.018% and 0.164% at pressure 133.32 kPa and 202.65 kPa, respectively.

Introduction/Background Our aim was to evaluate the efficacy of polydeoxynucleotide (PDRN) injections compared to standardized prolotherapy for patients with lateral epicondylitis (LE). Material and method In this randomized, double-blind, active-controlled trial, eligible patients with LE received intra-tendinous injections (1 mL of PDRN or hypertonic dextrose [15%]) under ultrasound (US) guidance at weeks 0, 2 and 4. Primary outcome was Visual Analogue Scale (VAS) for elbow pain. Secondary outcomes were pain-free grip strength (PFGS), pressure-pain threshold (PPT), isokinetic wrist extensor strength (IWES), patient-rated tennis elbow evaluation (PRTEE), EQ-5D-5L and US characteristics of the LE. All outcomes and adverse events were assessed at weeks 0, 6 and 12. Results The final analysis included 38 patients (PDRN injection, n = 19; prolotherapy, n = 19) (Fig. 1) (Table 1). Significant improvements from baseline to 12 weeks were observed in VAS for elbow pain in both groups (53.6 ± 19.1 mm, P Conclusion PDRN injections and prolotherapy used as standardized interventions can be safe and effective treatments improving for LE-related pain and function.

Methods of the characteristics evaluation of turbo-molecular pumps (TMP) are well-defined in the international measurement standards such as ISO, PNEUROP, DIN, JIS, and AVS. The Vacuum Center in the Korea Research Institute of Standards and Science (KRISS) has recently designed, constructed, and established the integrated characteristics evaluation system of TMPs based on the international documents by continuously pursuing and acquiring the reliable international credibility through measurement perfection. The measurement of TMP pumping speed is normally performed with the throughput and orifice methods dependent on the mass flow regions. However, in the UHV range of the molecular flow region, the high uncertainties of the gauges, mass flow rates, and conductance are too critical to precisely accumulate reliable data. In order to solve the uncertainty problems of pumping speeds in the UHV range, we introduced a SRG with 1% accuracy and a constant volume flow meter (CVFM) to measure the finite mass flow rates down to Pa-L/s with 3% uncertainty for the throughput method. In this way we have performed the measurement of pumping speed down to Pa with an uncertainty of less than 6% for a 1000 L/s TMP. In this article we suggest that the CVFM has an ability to measure the conductance of the orifice experimentally with flowing the known mass through the orifice chambers, so that we may overcome the discontinuity problem encountering during introducing two measurement methods in one pumping speed evaluation sequence.

We present a new algorithm for solving viscoelastic flows with a general constitutive equation. In our approach the hyperbolic constitutive equation is split such that the term for the convective transport of stress tensor is treated as a source. This allows the stress tensor at each grid point to be expressed mainly in terms of the velocity gradient tensor at the same point. Then, the set of six stress tensor components is found after inverting a six by six matrix at each grid point. Thus we call this algorithm the grid-by-grid inversion method. The convective transport of stress tensor in the constitutive equation, which has been treated as a source, is updated iteratively. The present algorithm can be combined with finite volume method, finite element method or the spectral methods. To corroborate the accuracy and robustness of the present algorithm we consider viscoelastic flow past a cylinder placed at the center between two plates, which has served as a benchmark problem. Also considered is the investigation of the pattern and strength of the secondary flows in the viscoelastic flows through a rectangular pipe. It is found that the present method yields accurate results even for large relaxation times.

The need to know the pressure in relatively large vacuum chambers arises at different measurements (calibration of vacuum gauges, outgassing measurements, etc.) and investigating the ways to minimize these pressure differences are of equal importance in such industrial as well as research applications. The experimental determination of the pressure differences between various gauge positions in a chamber of cylindrical shape and the effect of a baffle on pressure distribution are described in the paper. The pressure in the chamber was generated dynamically in the pressure range 0.1–133 Pa through adjustable gas flow into the chamber. Five identical capacitance diaphragm gauges (CDGs) were used in which one CDG remained fixed at the central position of the chamber while the other four (in two pairs) were mutually interchanged. The differences on the order of several percent between positions at different levels were calculated and the effect of the baffle was investigated which are specific for this chamber.

The streaming potential of electrokinetic flows in microchannels affects flow rate and is usually exploited to determine the zeta potential of microchannels. In the present investigation, we derive a semianalytic formula for the streaming potential of microchannels with arbitrary cross-sectional shapes valid for high zeta potentials as well as reasonably low zeta potentials. This formula satisfies the Onsager reciprocity principle at the limit of low zeta potential where the Debye-Hückel approximation is valid. The simple semianalytic formula for the streaming potential derived in the present work can be employed to investigate electrokinetic flows and determine the zeta potentials of microchannels with arbitrary cross-sectional shapes.

In the present investigation, we develop a method for estimating rheological parameters of viscoelastic fluids using velocity measurement in a square straight channel. It is believed that a somewhat complicated patterns of secondary flows due to the non-zero second normal stress difference are more useful than the simple viscometric flows traditionally adopted in the determination of rheological parameters. The inverse problem of determining the rheological parameters from a set of velocity measurements is solved using a conjugate gradient method. When applied to a general constitutive equation encompassing the UCM model, the Oldroyd-B model and the PTT model, the present method is found to yield a reasonably accurate estimation of five rheological parameters simultaneously even with noisy velocity measurements.

Time constant is an important property of the continuous flow systems that can be used to estimate the dynamic equilibrium time for the reaction vacuum chamber of such systems. This work is concerned with measurements and analysis of time constant of a dynamic flow control system assembled at the KRISS vacuum laboratory. Being a new system, it was important to know some basic characteristics of the system, including the time constant as well, in the pressure range of 0.1–133 Pa during continuous gas flow. Three types of gases were used for this purpose and the results were compared. It was observed that time constant was dependent on pressure across the conductance-reducer (CR) that was installed in the by-pass pumping line of the system. At low upstream pressures, the time constant was large and vice versa.

The bilateral comparison of high vacuum primary standards between the Korea Research Institute of Standards and Science (KRISS) and the National Measurement Institute of Japan (NMIJ) was performed in the nominal pressure range 4.09 × 10 −3 Pa to 1.22 × 10 −2 Pa by using two spinning rotor gauges as transfer standards. The accommodation coefficients ( σ ) of the two rotors for N 2 determined by the two laboratories agreed to within 0.17% for rotor 10 and 0.89% for rotor 11. This agreement is within the expanded uncertainties ( k = 1) of the primary standards at the two laboratories.

The Korea Superconducting Tokamak Advanced Research (KSTAR) project is the major effort of the national fusion programme of the Republic of Korea. Its aim is to develop a steady state capable advanced superconducting tokamak to establish a scientific and technological basis for an attractive fusion reactor. The major parameters of the tokamak are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T and plasma current 2 MA, with a strongly shaped plasma cross-section and double null divertor. The initial pulse length provided by the poloidal magnet system is 20 s, but the pulse length can be increased to 300 s through non-inductive current drive. The plasma heating and current drive system consists of neutral beams, ion cyclotron waves, lower hybrid waves and electron cyclotron waves for flexible profile control in advanced tokamak operating modes. A comprehensive set of diagnostics is planned for plasma control, performance evaluation and physics understanding. The project has completed its conceptual design and moved to the engineering design and construction phase. The target date for the first plasma is 2002.

In search of low-outgassing vacuum material, TiN and h-BN thin films were grown on stainless steel by ion beam assisted deposition (IBAD). The film structures and surface chemistries were studied by XRD, FT-IR, XPS, and Auger depth profile. The outgassing rates of bare, TiN coated, and two h-BN coated AISI 304 samples were compared by using thermal desorption spectroscopy. XPS showed that some Ti–Ti bonds remained in as-deposited TiN, and these excess Ti seemed to cause a sharp increase in H 2 peak at 360°C. All coatings reduced the outgassing, but the h-BN sample grown at a substrate temperature of 200°C had the lowest outgassing rate.

A survey among 806 brothel-based sex workers found that over 90 per cent were well informed of the seriousness of HIV and AIDS, modes of transmission and the effectiveness of condom use. Although the majority (73 per cent) always negotiated condom use with clients, they were successful with only half of them. Perceived barriers and low self-efficacy, rather than lack of knowledge, were found to be related to condom negotiation. Sex workers should be taught improved negotiation skills, and health education should be targeted at clients and brothel keepers to promote condom use.

Objective To estimate maternal and neonatal outcomes in women with preterm prelabour rupture of membranes (PPROM) who delivered at 34+0 to 36+6weeks' gestation, particularly in those who had an obstetrically indicated delivery. Methods We conducted a population-based study of late preterm singleton births complicated by PPROM, using data from the Nova Scotia Atlee Perinatal Database from 1988 to 2006. The study cohort was categorized by type of labour (spontaneous, induced, no labour), and each group's characteristics prior to delivery, and their outcomes were compared after accounting for potential confounding variables. Results From a total population of 164 384 pregnancies, 2618 deliveries were identified as having PPROM. Among these, 2180 (83.3%) delivered between 34+0 and 36+6weeks' gestation. Adjusted analyses showed no differences in risk between those women entering labour spontaneously (n=1296) and those with obstetrically indicated delivery (labour induction or Caesarean section without labour, n=698). Additional adjusted analyses evaluating only women with obstetrically indicated delivery showed that rates of chorioamnionitis (OR 0.27; 95% CI 0.08 to 0.93), composite perinatal morbidity/mortality (OR 0.39; 95% CI 0.25 to 0.62), neonatal depression at birth (OR 0.22; 95% CI 0.06 to 0.86), and respiratory distress syndrome (OR 0.17; 95% CI 0.06 to 0.47) were significantly lower in those delivering at 36weeks (n=458) than in those delivering at 34 to 35weeks (n=240). Conclusions This large population-based study suggests that in pregnancies complicated by PPROM rates of adverse maternal and perinatal outcomes at 36weeks' gestational age are at least comparable to those in pregnancies delivering at 34 to 35weeks, and these rates may be further reduced by delivery after 36 completed weeks if spontaneous labour has not occurred.

Objective Placental extracts (PE) have been used for years as a folk remedy in Asian countries. PE mediates alleviation of menopausal symptoms, wound healing, liver regeneration and anti-inflammatory responses. In this study, we evaluated the protective effects of PE on rats exposed to benzo[a]pyrene (BaP). Methods The composition of amino acids, sugars and fatty acids in PE was analyzed. The effect of PE on DNA damage was determined by Comet assay, and oxidative damage was determined by measuring the activity of superoxide dismutase and the levels of lipid peroxidation. The effect of PE on cytokines and immunoglobulin levels was determined by western blot analysis. Results Exposure of rats to BaP significantly increased the Olive Tailmoments compared to controls, while pre-treatment with PE composed of diverse amino acids, monosaccharides and fatty acids significantly decreased the Olive Tailmoments induced by BaP. In addition, oxidative stress induced by BaP was attenuated by pre-treatment with PE. Furthermore, PE pre-treatment significantly decreased the levels of pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6. Conclusion Pre-treatment of rats with PE significantly attenuates oxidative damage and immunotoxicity induced by BaP. These findings suggest the further studies regarding the protective effects of PE against environmental toxicants in humans.

The effects of annealing ambient (Ar, N 2 , O 2 and N 2 O) and durations (60 and 200 s) of rapid thermal annealing (RTA) on the insulating property of RF sputtered tantalum pentoxide films were examined. It was found that films sputtered at 200 W were more leaky than those sputtered at 100 W. It was also discovered that RTA in O 2 and N 2 O and at a longer duration (200 s) improved the insulating property of the films. This improvement was suggested to be due to a layer of SiO 2 formed at the Si-Ta 2 O 5 interface when annealed. The conduction mechanism for the O 2 and N 2 O annealed films was found to be of Poole-Frenkel type.

Diagnosis techniques based on the dissolved gas analysis (DGA) have been developed to detect incipient faults in power transformer. There are various methods based on DGA such as IEC, Roger, Dornenburg, and etc. However, these methods have been applied on the different problems with different standards. Also, it is difficult to achieve the diagnosis with accuracy by DGA without experienced experts. In order to resolve theses drawbacks, this paper proposes a novel diagnosis method using fuzzy clustering and a radial basis neural network (RBFNN). In neural network, fuzzy clustering is effective for selecting the efficient training data and reducing learning process time. After fuzzy clustering, the RBF neural network is developed to analysis and diagnosis the state of transformer. The proposed method measures the possibility and degree of aging as well as the faults occurred in transformer. To demonstrate the validity of proposed method, various experiments are performed and their result is presented.

Substation facilities have become large and complex in the electric power systems. Development of condition monitoring and diagnosis techniques has been very important to improve the security of substation transformers. This paper presents a method to analyze the cause, the degree, and process of aging of power transformers by self organizing map (SOM). Dissolved gas data were non-linearly transformed by the sigmoid function in SOM that works close to the process of how humans make a decision. The potential of failure and the degree of aging of normal transformers are identified by using the proposed quantitative criterion. Furthermore, the transformer aging is monitored by the proposed criterion for a set of transformers. To demonstrate the validity of the proposed method, a case study is performed and its results are presented.

Photovoltaic energy and wind energy are very in constant depending on the season, time and extremely intermittent energy sources. Because of these reasons, in view of the reliability the solar and the wind generation system have many problems(energy conversion, energy storage, load control etc.) comparing with a conventional power plant. So, in order to solve these existing problems, hybrid generation system of photovoltaic and wind power, which combines wind power energy and solar energy to have effect of supporting each other, was suggested. But, hybrid generation system cannot always generate stable output with weather condition, auxiliary generation apparatus that uses elastic energy of spiral spring to hybrid generation system was also added for the present study. And it may confirm that power was continuously provided to load by storing energy obtained from generating rotary energy of spiral spring generates in small scale generator.

The secondary electron emission coefficient? from MgO(magnesium oxide) protective layer of the geometrical surface profiles was studied. The? was measured by the method of ? -FIB system (focused ion beam system). The geometrical surface profiles on the MgO protective layers were made by the method of electron beam evaporation (e-gun) There was two type of MgO protective layer in this paper. The one type has the microscopic structures on the first MgO protective layer. To make this using by a mask of mesh fixed in front of the first layer in the e-gun chamber. The geometrical surface profiles on the MgO protective layer has been founded higher? values from 0.054 up to 0.114 than normal one ranged from 0.048 to 0.099 under Ne+ ion energies from 80V to 200V. The other type is made on the substrate of it has geometrical surface profiles already. This MgO protective layer was made by a screen printing and a photo lithography. The geometrical surface profiles on the MgO protective layer has been founded higher? values from 0.039 up to 0.094 than normal one ranged from 0.026 to 0.079 under Ne+ ion energies from 80V to 200V. Also it on the substrate of geometrical surface profiles has been founded? value from 0.043 up to 0.183 than normal one ranged from 0.038 to 0.154 under He+ ion energies from 80V to 200V.

MgO films as the protective layer in AC-PDPs has been annealed here under vacuum environment in order to eliminate absorbed material onto the MgO layer. Vacuum annealed can be one of the most important processes for forming long-lived panel. It is of great important to investigate the influence of vacuum annealed on the ion-induced secondary electron emission coefficient(/spl gamma/) from a MgO protective layer. In this research, /spl gamma/ and work-function of the vacuum annealed MgO films has been investigated by /spl gamma/-FIB(focused ion beam) system. Also the characteristics of /spl gamma/ and work-function for as-deposited and vacuum annealed MgO films have been investigated and compared with each other throughout this research. The MgO protective layer is deposited on the dielectric layer by electron beam evaporation at deposition rates of approximately 5/spl sim/10 /spl Aring//s in a vacuum of about 1.1/spl times/10/sup -6/ Torr. The thickness of MgO layer is about 5000 /spl Aring/. The deposited MgO films have been vacuum annealed at 300/spl deg/C for 15 minutes. Also some of the as-deposited MgO films and Vacuum annealed MgO films have been air-hold by 24-hours in this experiment. The /spl gamma/ and work-function characteristics for these two MgO films have been measured by /spl gamma/-FIB system and compared with each other throughout this experiment.

Summary form only given, as follows. Alternating current plasma display panel (AC-PDP) which uses a gas discharge is a display device with a inherent memory. The memory characteristics is that a cell experienced a gas discharge is easily fired by very low sustain voltage below a certain threshold voltage. In the widely-used surface discharged AC-PDP with three electrodes, the sustaining discharge occurs between the parallel-sustaining electrodes of X and Y on the front glass. But the wall charge is formed on the dielectric layer covering with X and Y electrode, and also formed on dielectric layer with data electrode Z on rear glass plate. Therefore the sustain discharge is affected by both the gas species and the quantity of wall charge on rear dielectrics. Under a certain wall charge configuration, the luminance efficiency is reduced because the wall charge prevents the normal sustaining discharge. In this experiment, we have adjusted the quantity of wall charge on rear glass plate by applying the data voltage on address electrode during the sustaining period. We have investigated the influence of data voltage on the discharge characteristics and luminance efficiency for the surface discharge of AC-PDPs. As a result it is found that the wall charge on the rear dielectrics has not been formed when the applied data voltage during the sustaining discharge period is reached to be about 50% of sustaining discharge voltage, where the highest luminance efficiency in AC-PDP could be achieved in this experiment.

Summary form only given. The characteristics of MgO film are very important for the development of recent AC-type plasma display panel(AC-PDP). An ion-induced secondary electron emission coefficient y is one of the MgO film characteristics which correlated to the ignition voltage of PDPs. MgO protective layers from sintered MgO and normal MgO are used for measurement of their work-function and secondary electron emission coefficients y in y-FIB system. Their sizes are 110mm/spl times/60mm and 5000A in thickness. The MgO protective layers are deposited on the dielectric layer by electron beam evaporation method. In this experiment, He, Ne, Ar, N/sub 2/, and Xe ions are used for the measurement of the y and the workfunction. From Auger neutralization mechanism, maximum kinetic energy E/sub k//sup max/ of the ejected secondary electron from MgO single crystal is given by E/sub k//sup max/ = E/sub i/-2/spl phi//sub /spl omega//, where E/sub i/ is the ionization energy and /spl phi//sub /spl omega// is the work-function for the MgO. The work-function can be obtained by /spl phi//sub /spl omega//=(E/sub i/-E/sub k//sup max/)/2, which is based on the Auger neutralization mechanism. For the zero emission of secondary electrons, i.e. /spl gamma/=0 from MgO surface, the maximum kinetic energy E/sub k//sup max/ of secondary electrons is E/sub k//sup max/=0. Hence the work-function /spl phi//sub /spl omega// with /spl gamma/=0 and E/sub k//sup max/=0 is given by /spl phi//sub /spl omega// =E/sub i//2, and where E/sub i/ is the ionization energy, which can be obtained by extrapolation of y versus the ionization energy for various gases, where /spl gamma/=0 from MgO. He, Ne, Ar, N/sub 2/, and Xe ions for different ionization energy are used for measurement of secondary electron emission coefficients along with the work function in /spl gamma/-FIB system. The MgO protective layer from sintered MgO has been found to have higher /spl gamma/ values from 0.0733 up to 0. 1168 than that from normal MgO ranged from 0.0258 to 0.1009 under Ne/sup +/ ion energies from 90eV to 200eV throughout this experiment. The work functions for the MgO protective layer deposited from sintered MgO and normal MgO have been found to be 5.32eV and 5.47eV, respectively, at the acceleration voltage of 90V. These results indicate that the work function of MgO protective layers is dependent on the secondary electron emission coefficient /spl gamma/. Based on these facts, it can be concluded that MgO protective layer deposited from sintered MgO plays an important role in lowering the firing voltages in AC-PDP compared with MgO protective layer from normal MgO.

The KSTAR (Korea Superconducting Tokamak Advanced Research) project is the major effort of the Korean National Fusion Program to design, construct, and operate a steady-state-capable superconducting tokamak. The project is led by Korea Basic Science Institute and shared by national laboratories, universities, and industry along with international collaboration. It is in the conceptual design phase and aims for the first plasma by mid 2002. The key design features of KSTAR are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T, plasma current 2 MA, and flexible plasma shaping (elongation 2.0; triangularity 0.8; double-null poloidal divertor). Both the toroidal and the poloidal field magnets are superconducting coils. The device is configured to be initially capable of 20 s pulse operation and then to be upgraded for operation up to 300 s with non-inductive current drive. The auxiliary heating and current drive system consists of neutral beam, ICRF, lower hybrid, and ECRF. Deuterium operation is planned with a full radiation shielding.

When a mobile host moves from a base station to another, the old base station may pre-forward data to neighboring base stations to avoid transmission delay. However, if other mobile hosts move at short intervals, the old base station may retransmit the same data to the same neighboring base stations. Also, the old base station should retransmit data if the new base station has already discarded data even if the new base station is a member of the multicast group. We propose the Information Exchange Scheme (IES) for resolving the above problems. In the scheme, each base station indirectly exchanges the data delivery information with other base stations in the same multicast group for efficient and reliable multicast, and pre-forwards data not retransmitting the same data when a mobile host moves. We also show how IES is efficient by analysis and simulation.