851 research outputs found

    Note: A simple-structured anode exchangeable X-ray tube

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    An anode exchangeable X-ray tube of very simple structure was developed. Aluminum, chromium, and copper anode targets were prepared and used to investigate X-ray spectra. X-ray images of a thin wood plate were taken using those targets. The measured energies of the characteristic X-rays of each target agreed well with the presented results. The difference of resolution and brightness of each image was found based on MTF values and intensities. The developed X-ray tube can give high durability, and higher quality X-ray images of an arbitrary object by exchanging anode targets.open1

    Experimental Study on the Acellular Demal Matrix Graft for the Root Coverage in Dog

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    Mucogingival surgery is a plastic surgical procedure designed to correct defects in the morphology, position, and dimensions of the gingiva surrounding the teeth. Many surgical techniques have been reported in mucogingival surgery. Since these procedures also include the soft tissue esthetic approach, the term periodontal plastic surgery has been proposed to be more appropriate.1 Root coverage is a procedure that falls with this definition, and it has attracted more interest than others

    Thermal performance evaluation of horizontal spiral coil-type ground heat exchangers

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    Geothermal energy has been widely used over the world instead of fossil fuel for environmental merits. A ground-source heat pump (GSHP) system utilizes a constant ground temperature to absorb heat during winter and to emit heat in summer. The GSHP system can be devieded into a closed type system and an open type system. The closed type system using a horizontal ground heat exchanger (HGHE) is relatively inexpensive and easy to install compared to the other types of systems. Among the types of HGHEs, since a horizontal spiral-coil type GHE has the advantageous arrangement for heat exchange between the heat exchanger and surrounding ground, it is the most effective type of the HGHE in terms of thermal performance. However, the thermal performance of a horizontal spiral-coil type GHE critically depends on its dimension which consists of the radius and pitch of a spiral, and thus it is important to accurately analyze how the radius and pitch affect the thermal performance of the horizontal spiral-coil type GHE. Therefore, this paper investigated the thermal performance of a horizontal spiral-coil type GHE according to its diverse shapes to suggest a beneficial design specification of the horizontal spiral-coil type GHE. In order to evaluate the thermal performance of the heat exchanger, a spiral-coil type HGHE was installed in a steel box of which the size was 5 m x 1 m x 1 m filled with dry Joomunjin standard sand, and a thermal response test (TRT) was conducted for 30 hours continuously. Besides, a numerical analysis was performed for its verification and a parametric study of the horizontal spiral-coil GHE using a numerical program which is based on a finite element method (FEM). As a result, in case that the pitch of the horizontal spiral-coil type GHE was more than 0.6 m, there was no more significant benefit in the thermal performance

    Data Assimilation of AOD and Estimation of Surface Particulate Matters over the Arctic

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    In this study, more accurate information on the levels of aerosol optical depth (AOD) was calculated from the assimilation of the modeled AOD based on the optimal interpolation method. Additionally, more realistic levels of surface particulate matters over the Arctic were estimated using the assimilated AOD based on the linear relationship between the particulate matters and AODs. In comparison to the MODIS observation, the assimilated AOD was much improved compared with the modeled AOD (e.g., increase in correlation coefficients from −0.15–0.26 to 0.17–0.76 over the Arctic). The newly inferred monthly averages of PM10 and PM2.5 for April–September 2008 were 2.18–3.70 μg m−3 and 0.85–1.68 μg m−3 over the Arctic, respectively. These corresponded to an increase of 140–180%, compared with the modeled PMs. In comparison to in-situ observation, the inferred PMs showed better performances than those from the simulations, particularly at Hyytiala station. Therefore, combining the model simulation and data assimilation provided more accurate concentrations of AOD, PM10, and PM2.5 than those only calculated from the model simulations

    Data Assimilation of AOD and Estimation of Surface Particulate Matters over the Arctic

    Get PDF
    In this study, more accurate information on the levels of aerosol optical depth (AOD) was calculated from the assimilation of the modeled AOD based on the optimal interpolation method. Additionally, more realistic levels of surface particulate matters over the Arctic were estimated using the assimilated AOD based on the linear relationship between the particulate matters and AODs. In comparison to the MODIS observation, the assimilated AOD was much improved compared with the modeled AOD (e.g., increase in correlation coefficients from −0.15–0.26 to 0.17–0.76 over the Arctic). The newly inferred monthly averages of PM10 and PM2.5 for April–September 2008 were 2.18–3.70 μg m−3 and 0.85–1.68 μg m−3 over the Arctic, respectively. These corresponded to an increase of 140–180%, compared with the modeled PMs. In comparison to in-situ observation, the inferred PMs showed better performances than those from the simulations, particularly at Hyytiala station. Therefore, combining the model simulation and data assimilation provided more accurate concentrations of AOD, PM10, and PM2.5 than those only calculated from the model simulations

    A Family of H723R Mutation for SLC26A4 Associated with Enlarged Vestibular Aqueduct Syndrome

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    Recessive mutations of the SLC26A4 (PDS) gene on chromosome 7q31 can cause sensorineural deafness with goiter (Pendred syndrome, OMIM 274600) or NSRD with goiter (at the DFNB4 locus, OMIM 600791). H723R (2168A>G) is the most commonly reported SLC26A4 mutations in Korean and Japanese and known as founder mutation. We recently experienced one patient with enlarged vestibular aqueduct syndrome. The genetic study showed H723R homozygous in the proband and H723R heterozygous mutation in his family members. The identification of a disease-causing mutation can be used to establish a genotypic diagnosis and provide important information to both families and their physicians
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