• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.9
• /
• pp.1296-1302
• /
• 2009

Ninety six beak-trimmed 72 week-old Lohmann Brown hens were randomly divided into four equal groups. Each group comprised 4 replicates. Isoenergetic and isonitrogenous experimental diets contained low calcium (3.5%); optimum calcium (4.2%); low Ca (3.5% Ca)+1% Clinoptilolite (CLP); low Ca (3.5% Ca)+2% CLP. Data were collected biweekly and the experiment lasted 6 weeks. Egg production, feed consumption, feed conversion ratio, egg weight, tibia Ca, P, ash and eggshell thickness were not affected by addition of CLP to the diets (p>0.05). There were no significant differences in egg shell strength and ash when data were analyzed individually in measurement periods ($74^{th}$, $76^{th}$ and $78^{th}$ weeks). However, according to pooled data ($74^{th}$-$78^{th}$ weeks), eggshell strength was increased (p<0.05) only by 2% CLP supplementation versus low Ca (3.5%) diet, and shell ash was significantly increased by 2% CLP supplementation compared with the other diets. The damaged egg ratio on 1% and 2% CLP diets was significantly decreased between 76-78 weeks'data when compared with the low Ca diet. However; damaged egg ratio on the 2% CLP diet was significantly decreased when pooled data (74-78) were compared with no CLP diets. The differences in marketable egg ratio paralleled damaged egg ratio. The plasma calcium level at the end of experiment was increased on the 2% CLP diet when compared with the low Ca (3.5%) diet (p<0.05). Furthermore, at the end of the experiment a marked decrease of manure moisture was observed on both CLP diets (p<0.01). In conclusion, Clinoptilolite (2%) supplementation to layer diets tends to improve eggshell quality and manure dry matter (1% and 2% CLP) after six weeks.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.17 no.2
• /
• pp.44-58
• /
• 2014

In this study, a standard vector data model was developed for interoperability of river-geospatial information and for verification purpose the applicability of the standard vector model was evaluated using a model to RIMGIS vector data at Changnyeong-Hapcheon & Gangjung-Goryeong irrigation watershed. The standards from ISO and OGC were analyzed and the river geospatial data model standard was established by applying the standards. The ERD was designed based on the analysis information on data characteristics and relationship. The verification of RIMGIS vector data included points, lines and polygon to develope GDM was carried out by comparing with the data by layer. This conducting comparison of basic spatial data and attribute data to each record and spatial information vertex. The error in the process of conversion was 0 %, indicating no problem with model. Our Geospatial Data Model presented in this study provides a new and consistent format for the storage and retrieval of river geospatial data from connected database. It is designed to facilitators integrated analysis of large data sets collected by multiple institutes.

• The Journal of Engineering Geology
• /
• v.26 no.1
• /
• pp.117-128
• /
• 2016

Chemical reaction tests were performed to assess the properties of hardened specimens of cement pastes (KS-1 Portland and Class G) exposed to supercritical CO₂ for 1, 10, and 100 days. After exposure, the samples' measured permeability and strength were compared with values measured for pristine samples. The pristine cements had permeabilities of 0.009~0.025 mD, which increased by one order of magnitude after 100 days of exposure (to 0.11~0.29 mD). The enhancement of permeability is attributed to the stress release experienced by the samples after removal from the pressure vessel after exposure. Despite its enhancement, the measured permeability mostly remained lower than the API (American Petroleum Institute) recommended maximum value of 0.2 mD. The degradation of the cement samples due to exposure to supercritical CO₂ led to a layer of altered material advancing inwards from the sample edges. The Vickers hardness in the altered zone was much higher than that in the unaltered zone, possibly owing to the increase in density and the decrease in porosity due to the carbonation that occurred in the altered zone. Hardness close to the edge within the altered zone was found to have decreased significantly, which is attributed to the conversion of C-S-H into less-strong amorphous silica.

• Korean Journal of Materials Research
• /
• v.20 no.4
• /
• pp.210-216
• /
• 2010

This paper investigates the dependence of a-Si:H/c-Si passivation and heterojunction solar cell performances on various cleaning processes of silicon wafers. It is observed that the passivation quality of a-Si:H thin-films on c-Si wafers depends highly on the initial H-termination properties of the wafer surface. The effective minority carrier lifetime (MCLT) of highly H-terminated wafer is beneficial for obtaining high quality passivation of a-Si:H/c-Si. The wafers passivated by p(n)-doped a-Si:H layers have low MCLT regardless of the initial H-termination quality. On the other hand, the MCLT of wafers incorporating intrinsic (i) a-Si:H as a passivation layer shows sensitive variation with initial cleaning and H-termination schemes. By applying the improved cleaning processes, we can obtain an MCLT of $100{\mu}sec$ after H-termination and above $600{\mu}sec$ after i a-Si:H thin film deposition. By adapting improved cleaning processes and by improving passivation and doped layers, we can fabricate a-Si:H/c-Si heterojunction solar cells with an active area conversion efficiency of 18.42%, which cells have an open circuit voltage of 0.670V, short circuit current of $37.31\;mA/cm^2$ and fill factor of 0.7374. These cells show more than 20% pseudo efficiency measured by Suns-$V_{oc}$ with an elimination of series resistance.

• Korean Journal of Poultry Science
• /
• v.40 no.4
• /
• pp.379-388
• /
• 2013

Avian paramyxovirus (APMV) type 4 and 6 were isolated during an avian influenza (AI) surveillance program of wild birds. This study also conducted experimental infection of wild-bird-origin APMV type 4 and 6 in specific pathogen free (SPF) chickens to study pathogenicity and transmission within domestic flocks. In addition, serological prevalence data of APMV type 4 and 6 in domestic fowls was conducted with chicken sera collected from 2007 to 2009 in order to understand infection status. The results of the animal experiment showed that APMV type 4 and 6 had the ability to infect chickens with sero-conversion and to transmit the virus from infected birds to contacted birds, but showed low pathogenicity. Serological tests revealed that APMV type 4 was widespread in the poultry industry, especially in layer flocks, but the positive rate for APMV type 6 was very low. This study concluded that wild bird-origin APMV type 4 and 6 could infect the chickens by inter-species transmission and the seroprevalence of APMV type 4 was quite high in Korean poultry. However, since almost all the chicken flocks had a high level of antibody titer against APMV type 1, there was possibility of cross reaction between APMV type 1 and 4, which made the interpretations more complicated. In order to understand infection status in the natural environment, additional study is necessary regarding the seroprevalence of APMV type 4 and 6 in the wild bird population.

• Journal of Advanced Marine Engineering and Technology
• /
• v.39 no.3
• /
• pp.223-229
• /
• 2015

Surface modification is a technology to form a new surface layer and overcome the intrinsic properties of the base material by applying thermal energy or stress onto the surface of the material. The purpose of this technique is to achieve anti-corrosion, beautiful appearance, wear resistance, insulation and conductance for base materials. Surface modification techniques may include plating, chemical conversion treatment, painting, lining and surface hardening. Among which, a surface modification process using electrolytes has been investigated for a long time in connection with research on its industrial application. The technology is highly favoured by various fields because it provides not only high productivity and cost reduction opportunities, but also application availability for components with complex geometry. In this study, an electrochemical experiment was performed on the surface of 5083-O Al alloy to determine an optimal electrolyte temperature, which produces surface with excellent corrosion resistance under marine environment than the initial surface. The experiment result, the modified surface presented a significantly lower corrosion current density with increasing electrolyte temperature, except for $5^{\circ}C$ of electrolyte temperature at which premature pores was created.

• Journal of the Korean Society of Radiology
• /
• v.3 no.4
• /
• pp.29-33
• /
• 2009

Recently, the compound materials(a-Se, $HgI_2$, PbO, CdTe, $PbI_2$, etc.) that are used in flat panel x-ray imager have been studied for digital x-ray imaging. In this paper, the signal detection properties of $HgI_2$ and a-Se conversion layer, are compared. The thick $HgI_2$ film is fabricated by special particle-in-binder method and the conventional vacuum thermal evaporation is used for a deposition of a-Se film. And an electrical characteristic measurements were investigated about leakage current, signal response property and x-ray sensitivity. From the experimental results show that the $HgI_2$ film has a low operation voltage and high signal generation than that of a-Se.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.41 no.9
• /
• pp.700-707
• /
• 2013

Experimental analyses on a supersonic plasma wind tunnel of CBNU (Chonbuk National University) were carried out. In these experiments, a segmented arc heater was employed as a plasma source and operated at the gas flow rates of 16.3 g/s and the total currents of 300 A. The input power reached ~350 kW with the torch efficiency of 51.4 %, which is defined as the ratio of total exit enthalpy to the input power. The pressure of plasma gas in the arc heater was measured up to 4 bar while it was down to ~45 mbar in a vacuum chamber through a Laval nozzle. During this conversion process, the generated supersonic plasma was expected to have a total enthalpy of ~11 MJ/kg from the measured input power and torch efficiency. In addition to the measurement of total enthalpy, a cone type probe was inserted into the supersonic plasma flow in order to estimate the angle between shock layer and surface of the probe. From these measurements, the temperature and the Mach number of the supersonic plasma were predicted as ~2,950 K and ~3.7, respectively.

• Development and Reproduction
• /
• v.14 no.2
• /
• pp.115-121
• /
• 2010

The in vitro effects of nonylphenol (NP) and 2,2',4,6,6'-pentachlorobiphenyl (PCB104) on ovarian steroidogenesis of the ribbed gunnel, Dictyosoma burgeri were investigated. Oocytes taken during maturation stage were incubated with 100 ng/$m{\ell}$ of NP and PCB104 in the presence of exogenous precursor, $[^3H]-17{\alpha}$-hydroxyprogesterone ($[^3H]-17{\alpha}OHP$). Steroids were extracted from the media and the isolated oocytes, and the extracts were separated and identified by thin layer chromatography. The identities of the major metabolites were testosterone (T) and estradiol-$17{\beta}$ (E2). NP treatment inhibited production of E2 metabolite in the oocytes of 1.2, 1.3 and 1.4 mm although NP inhibited production of T metabolite at the oocytes of 1.1, 1.3 and 1.4 mm. PCB104 treatment inhibited production of T metabolite in the oocytes of all groups and E2 metabolite in the oocytes of 1.2, 1.3 and 1.4 mm. In conclusion, these results suggested that NP and PCB104 had an inhibitory effects on conversion of $[^3H]-17{\alpha}OHP$ to T and E2 during the oocyte maturation process of ribbed gunnel.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.4 no.4 s.15
• /
• pp.43-54
• /
• 2004

The broadband receiver functions are developed from teleseismic P waveforms recorded at Wonju(KSRS), Inchon(IRIS), and Pohang(PHN), and are analyzed to examine the crustal structure beneath these stations. The teleseismic receiver functions are inverted in the time domain of the vertical P wave velocity structures beneath the stations. Clear P-to-S converted phases from the Moho interface are observed in teleseismic seismograms recorded at these stations. The crustal velocity structures beneath the stations are estimated by using the receiver function inversion method(Ammon et al., 1990). The general features of inversion results are as follows: (1) For the Inchon station, the Conrad discontinuity exists at 17.5 Km(SW) deep and the Moho discontinuity exists at 29.5 Km(NW) and 30.5 Km(SE, SW) deep. (2) The shallow crustal structure beneath Wonju station may be covered with a sedimentary rock of a 3 Km thickness. The average Moho depth is assumed about 33.0 Km, and the Conrad discontinuity may exist at 17.0 Km(NE) and 21.0 Km(NW) deep. (3) For Pohang station, the thickness of shallow sedimentary layer is a 3.0 Km in the direction of NE and NW. The Moho depth is 28.0 Km in the direction of the NE and NW. The Conrad discontinuity can be estimated to be existed at 21.0 Km deep for the NE and NW directions.