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To improve the dispersion of graphene nanoplatelet (GNP) in polypropylene (PP), GNP was exfoliated in a mixed solvent of p-xylene and N,N-dimethylform-amide (DMF) and the exfoliation of GNP was maintained by the addition of a compatibilizer before the melt blending. The concentration of the dispersed GNP in various ratios of the mixed solvents was measured in order to confirm the effect of the mixed solvent on the pre-treatment process. As a compatibilizer for the composite, pyrene-functionalized maleic anhydride-grafted polypropylene (Py-PP) was synthesized. The dispersion state of the composites was analyzed by the three dimensional non-destructive X-ray micro-computed tomography (3D micro-CT). The improved dispersion of GNP resulted in a significant enhancement in the mechanical properties. Young’s modulus of PP composites with 2 wt% GNP has increased by 43% compared with that of PP. These results are attributed not only to the improved interfacial interaction between PP and GNP, but also to the homogeneous dispersion state of the GNP in the matrix.

Resumen Reportamos el caso de una paciente con cancer de mama, en la que la PET/TC osea doble fase con 18F-fluoruro de sodio (18F-NaF) resulto de utilidad para detectar metastasis oseas ocultas y valorar la respuesta al tratamiento. La paciente fue estudiada con PET/TC osea en doble fase de una lesion de nuevo desarrollo detectada en la gammagrafia posterior a la intervencion. En las imagenes PET/TC de perfusion y oseas, se encontraron captaciones en las fases de perfusion y osea, puntualmente incrementadas en el sacro y la vertebra L5, sugerentes de metastasis oseas del cancer de mama, por lo que se aplico a la paciente terapia paliativa. En las imagenes de PET/TC osea en doble fase, realizadas a los 3 y 6 meses, las imagenes de perfusion reflejaron mas claramente la mejora de la captacion de la lesion que las imagenes de la fase osea en los analisis visual y semicuantitativo. Por tanto, se utilizaron las imagenes de la fase de perfusion para esclarecer la respuesta a la terapia con mayor prontitud que las imagenes de la fase osea. Se trata del primer caso que refleja la utilidad clinica de la PET/TC osea con 18F-NaF, con la tecnica de imagen de perfusion, para evaluar las metastasis oseas y la respuesta terapeutica de las lesiones oseas metastasicas.

The main obstacles in the melt-processing of hydroxyapatite (HA) and carbon fiber (CF) reinforced polyetheretherketone (PEEK) composite are the high melting temperature of PEEK, poor dispersion of HA nanofillers, and poor processability due to high filler content. In this study, we prepared PEEK/HA/CF ternary composite using two different non-melt blending methods, suspension blending (SUS) in ethanol and mechanofusion process (MF) in dry condition. We compared the mechanical properties and bioactivity of the composite in a spinal cage application in the orthopedic field. Results showed that the PEEK/HA/CF composite made by the MF method exhibited higher flexural and compressive strengths than the composite prepared by the SUS method due to the enhanced dispersibility of HA nanofiller. On the basis of in vitro cell compatibility and cell attachment tests, PEEK/HA/CF composite by mechanofusion process showed an improvement in in vitro bioactivity and osteo-compatibility.

Various studies have indicated that particulate matter &lt, 2.5 &mu, m (PM2.5) could cause adverse health effects on pulmonary functions in susceptible groups, especially asthmatic children. Although the impact of ambient PM2.5 on children&rsquo, s lower respiratory health has been well-established, information regarding the associations between indoor PM2.5 levels and respiratory symptoms in asthmatic children is relatively limited. This randomized, crossover intervention study was conducted among 26 asthmatic children&rsquo, s homes located in Incheon metropolitan city, Korea. We aimed to evaluate the effects of indoor PM2.5 on children&rsquo, s peak expiratory flow rate (PEFR), with a daily intervention of air purifiers with filter on, compared with those groups with filter off. Children aged between 6&ndash, 12 years diagnosed with asthma were enrolled and randomly allocated into two groups. During a crossover intervention period of seven weeks, we observed that, in the filter-on group, indoor PM2.5 levels significantly decreased by up to 43%. (p &lt, 0.001). We also found that the daily or weekly unit (1 &mu, g/m3) increase in indoor PM2.5 levels could significantly decrease PEFR by 0.2% (95% confidence interval (CI) = 0.1 to 0.5) or PEFR by 1.2% (95% CI = 0.1 to 2.7) in asthmatic children, respectively. The use of in-home air filtration could be considered as an intervention strategy for indoor air quality control in asthmatic children&rsquo, s homes.

Copper sulfide (CuS) thin films were deposited on a glass substrate at room temperature using the radio-frequency (RF) magnetron-sputtering method at RF powers in the range of 40−100 W, and the structural and optical properties of the CuS thin film were investigated. The CuS thin films fabricated at varying deposition powers all exhibited hexagonal crystalline structures and preferred growth orientation of the (110) plane. Raman spectra revealed a primary sharp and intense peak at the 474 cm−1 frequency, and a relatively wide peak was found at 265 cm−1 frequency. In the CuS thin film deposited at an RF power of 40 W, relatively small dense particles with small void spacing formed a smooth thin-film surface. As the power increased, it was observed that grain size and grain-boundary spacing increased in order. The binding energy peaks of Cu 2p3/2 and Cu 2p1/2 were observed at 932.1 and 952.0 eV, respectively. Regardless of deposition power, the difference in the Cu2+ state binding energies for all the CuS thin films was equivalent at 19.9 eV. We observed the binding energy peaks of S 2p3/2 and S 2p1/2 corresponding to the S2− state at 162.2 and 163.2 eV, respectively. The transmittance and band-gap energy in the visible spectral range showed decreasing trends as deposition power increased. For the CuS/tin sulfide (SnS) absorber-layer-based solar cell (glass/Mo/absorber(CuS/SnS)/cadmium sulfide (CdS)/intrinsic zinc oxide (i-ZnO)/indium tin oxide (ITO)/aluminum (Al)) with a stacked structure of SnS thin films on top of the CuS layer deposited at 100 W RF power, an open-circuit voltage (Voc) of 115 mA, short circuit current density (Jsc) of 9.81 mA/cm2, fill factor (FF) of 35%, and highest power conversion efficiency (PCE) of 0.39% were recorded.

Purpose To evaluate the effects of air purifiers on the concentrations of indoor air pollutants and on asthma control in children. Materials and methods In this randomized crossover trial, daily use of an air purifier filter was compared with a matched placebo with the filter off. Thirty elementary school students who had asthma were enrolled and randomly allocated to one of two groups. The primary endpoints were changes in indoor air quality, asthma severity, lung function, airway inflammatory, urine microbiome, and phthalate after the installation of air purifiers. PM2.5 and CO₂ were measured as indoor air pollutants. Asthma severity was assessed in terms of both symptom and medication scores acquired using a daily questionnaire. The higher the score, the better the symptom or the less frequent the use of medication. Peak expiratory flow rate and fractional exhaled nitric oxide were also measured. Results The mean age of the enrolled patients was 9.2±1.98 years. The mean concentration of PM2.5 was 17.0 μg/m³ in the filter-off condition, but significantly lower at 9.26 μg/m³ in the filter-on condition. Medication scores were 6.9 for the filter-off and 7.12 for the filter-on conditions, reflecting a statistically significant decrease in the frequency of medications used during air purifier operation. Bacterial richness, as determined using the Chao 1 index, was markedly lower in the filter-on than the filter-off condition. Conclusion This study suggests that air purifiers benefit medication burden in children with asthma by reducing PM2.5 levels.

This study aimed to evaluate the effect of oral iron supplementation in frequent donors in Korea, based solely on donation history.The hemoglobin (Hb) level, ferritin level, soluble transferrin receptor (sTfR), total iron binding capacity (TIBC), and transferrin saturation of frequent donors at high risk for iron deficiency were compared to those of first donors. The frequent donors took iron supplements for 4 weeks and the same tests were repeated after 2 and 4 weeks to evaluate their effects.A total of 53 male and 57 female frequent donors were recruited. After 4-week iron supplementation, among the men, the prevalence of a: low Hb level (13.0 g/dL) decreased from 25% to 2%; low ferritin level (15.0 ng/mL) decreased from 58% to 4%; iron deficient erythropoiesis (IDE) (log(sTfR/ferritin) ≥ 2.07) decreased from 77% to 33%. Among the women, the percentage of a: low Hb level (12.0 g/dL) decreased from 44% to 9%; low ferritin level decreased from 79% to 11%; IDE decreased from 95% to 47%. In total, 15 male (28.3%) and 29 female (56.9%) blood donors reported undesirable side effects related to iron supplementation. No serious adverse events were reported.Ferritin level, a reliable indicator of iron status, increased and IDE decreased significantly after four-week iron supplementation in the female, but not in the male, donor group, compared to those of control donors. Four-week oral iron supplement was not enough to restore iron storage level in the male donor group.

The turbocharger is an essential component to realize the engine down-sizing. The moment of inertia of turbocharger rotor is an important parameter with respect to acceleration performance of the vehicle. It can be calculated from the CAD software based the geometry data and the material properties. But the accurate value of the inertia of turbocharger rotor must be measured through the experimental method. In this study, the measurement of moment of inertia of turbocharger rotor for 2.0 L spark-ignition engine was carried out. First, an experimental equipment using a trifilar method was designed and fabricated. Some optical devices, that is, photo sensor, counter, convex lens, etc, were used to increase the accuracy of the measurement. Second, error sensitivity for the equipment was analyzed. The error of period time and the radius can give big affects to the accuracy of the moment of inertia. When the amount of error of these two were each 1.0 %, maximum error of the moment of inertia was under 3.0 %. Third, the calibration for the equipment was performed using a calibration rotor which has similar shape to turbine rotor but simple. Calculated value from CAD software and measured one for the calibration rotor were compared. The total error of the equipment and the measurement is about 1.3 %. This result shows that the equipment can give the good result with resonable accuracy. Finally the moment of inertia of the turbine rotor and compressor wheel were measured. The coefficient of variations, the ratio of standard deviation to mean value, were reasonably small at 0.57 % and 0.73 % respectively. Therefore this equipment is suitable for the measurement of the moment of inertia of the turbine rotor and compressor wheel.

Recently the increasing numbers of cars and traffic jamming makes air pollution condition more severely. Especially high-density population area, in most big cities like Bejing and Seoul, can lead to lung illness and other diseases. In this study to decrease this kind of air pollution condition, a method of air pollution information transmission is proposed. For the transmission of air pollution and traffic control data, international standard technology, the TPEG is applied. keywords : TPEG, air pollution data, traffic control data

This study used Computational Fluid Dynamics(CFD) to assess the properties of the air current inflow and the flow velocity distribution in the fume hood. In order to verify the effect of improvement, it was also predicted the characteristics of the flow pattern in case the hood face is structurally improved. The assessment of the capture velocity with the existing fume hood confirmed maximum 23 to 30% difference as compared to the root mean square (RMS). And the hood face showed great difference in flow velocity, with the flow velocity in the upper part is 58 to 68% faster than that in the lower part of the hood. So, as a result of the improvement of the hood designed to maintain a steady exhaust at the hood face (that is, installing a baffle on the inner wall and designing the slot type face), a difference of maximum 7% as compared to RMS appeared while maximum 12% differentiation in flow velocity through sections was predicted, showing mitigation of much of the difference in control velocity as compared to the previous structure.

AT-DMB was developed to raise the transmission rate of existing T-DMB with backward compatability. The transmission and hierarchical video service technique were legislated as Korean TTA standards, and other application service techniques including data services are being developed for the commercial service. In this paper, we consider the power of transmission power level of signals in Advanced Terrestrial Digital Multimedia System according to the constellation ratio. And we propose a new scheme for normalization of transmission signal power level in AT-DMB system. Adopting this scheme, the signal power level of hierarchical modulated signal can be uniform in AT-DMB system both for B Mode and Q Mode.

This paper presents the field trial results of the terrestrial digital multimedia broadcasting (T-DMB) service in Korea. The T-DMB system, based on the Eureka-147 digital audio broadcasting (DAB) system, provides streaming video, CD-quality audio and data services at speeds of up to 300 km/h using H.264 video codec along with additional channel coding and interleaving schemes. In order to provide seamless high-quality services on various radio channels, we measured the bit error rate (BER), electric field strength (EFS), and subjective video quality using specially-designed mobile test equipment. From the field tests we obtained the required effective EFS (EEFS) for error-free reception and also derived the minimum EFS from the link budget analysis. Furthermore, we present the optimal transmit and receive parameters for constructing the T-DMB networks and also developing T-DMB broadcasting equipment and mobile receivers

A new mobile multimedia broadcasting service using a geostationary satellite was launched on May 2005 in Korea. The Satellite Digital Multimedia Broadcasting (S-DMB) system provides high quality audio, video and data broadcasting services to handheld and mobile receivers. S-DMB is a personal digital media which can provide bidirectional and interactive services via the convergent platform of broadcasting and communication. At present, TU Media, the only S-DMB service provider in Korea, provides 15 TV channels, 19 audio channels, and 3 data channels. The number of subscribers is about 890,000 by Nov. 2006. Thousands of low power gap fillers (repeaters) have been installed in the shadowed or blocked reception areas in the metropolitan Seoul. This paper presents the system requirements, standards and specifications, architecture, and service status of S-DMB in Korea. Comparisons with other satellite broadcasting systems and the services are also presented. Link budget analysis on the direct path down-link (satellite to receivers) and relay path feeder link (gap fillers to receivers) are carried out in order to ensure the satisfactory QoS

In this paper, we proposed a Depth Sensor Combined Display Contents Control System. Gestures recognition using depth sensor is generally composed of three steps as modeling, analysis, recognition. Gesture modeling is to create mathematical model of recognized gestures [1–2]. The approach for modeling can conduct a pivotal role in the gesture recognition and gesture analysis performance. If model is created, it can recognize gestures through parameters extracted from the input video. So, in this paper, we proposed a Depth Sensor Combined Display Contents Control System.

A solvent-assisted drop-casting technique is introduced for the active layer formation in fabricating polymer thin-film transistors (TFTs). This method allows one to lower the rate of film formation (or deposition) of polymer semiconductor and to use a higher temperature, both factors contributing to better ordering of the semiconducting polymer. A notable increase in mobility results when the technique is applied to fabricating the polymer TFT. More important is the stability of the device that the method provides.

In this study, nano-sized indium oxide powder with average particle size below 50 nm is synthesized from indium chloride solution by a spray pyrolysis process. This study also examines influences of reaction factors on the properties of the synthesized powder. These factors include the reaction temperature, the inflow speed of the raw material solution and the inflow speed of the environmental air. As the reaction temperature increases from 850 to 1000°C, the average particle size of the generated powder increases from around 30 nm to 100 nm, the microstructure gradually becomes solid, the XRD peak intensity gradually increases and the specific surface area decreases. As the inflow speed of the raw material solution increases from 2 to 5 mL/min, the average particle size of the powder decreases. When the inflow speed is 10 mL/min, the average particle size is larger than that at 5 mL/min. When the inflow speed of solution is 50mL/min, the average particle size is smaller and the microstructure of the powder is less solid than that at 10 mL/min. The variations of the XRD peak intensity and the specific surface area show the similar tendency to that of the average particle size. As the air pressure increases from 0.1 to 0.5 kg/cm 2 , the average particle size of the powder shows a not significant change from 90 nm to 100 nm. As the air pressure increases up to 1 kg/cm 2 and 3 kg/cm 2 , the average particle size decreases down to 50 nm and the XRD peak intensity decreases.

Many countries gather information for the road surface condition related weather. But there are no proper way to give the gathered information to the drivers on the roads. In this paper a method to transmit the road information especially related with weather condition. The proposed method is testified via terrestrial digital multimedia broadcasting system, and can be deployed for other digital mobile broadcasting system for example DAB, HD Radio, etc.

Recently, in digital broadcasting, audio loudness control has emerged as an important issue. Therefore, several standardizations for audio loudness have been legislated by ITU, ATSC, and EBU; further some countries have started to put regulation on television programs to prevent discomfort in loudness. In this paper, we examine the international standards on broadcast loudness standard and their deployment trends. The purpose of this paper is to make secure foundation for the introduction of broadcast loudness standard policy and its early realization and settlement.

Many countries today face converting their analog radio broadcasting to digital service. Since the in-band digital radio systems are used in the existing analog FM frequency band, compatibility and robustness is very important characteristics of the digital radio systems. In this paper, we evaluate the performances of HD-Radio and DRM+ which are in-band digital radio broadcasting techniques in the various interference channel environment. These results are able to give basic information for the decision of digital radio standard in many countries.