• Journal of the Korean Society of Radiology
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• v.10 no.5
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• pp.327-335
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• 2016

The study is enforce to study image quality evaluation of condition provide the IEC and combination of clinical conditions each quality of radiation that image quality to assess the conditions provided to IEC in the clinical environment to conduct image quality assessment of the digital radiography system in the detector have environmental limits. First, image quality evaluation was evaluated by measuring the MTF, NPS using four quality of radiation and Using MCNPX simulation lastly DQE make a image quality evaluation after calculating the particle fluence to analyze spectrum quality of radiation. Second, Using MCNPX simulation of four quality of radiation was evaluated absorbed dose rate about electronic 1 per unit air, water, muscle, bone by using Radiation flux density and energy, mass-energy absorption coefficient of matter. Results of evaluation of image quality, MTF of four quality of radiation was satisfied diagnosis frequency domain 1.0 ~ 3.0 lp/mm of general X-ray that indicated 1.13 ~ 2.91 lp/mm spatial frequency. The NPS has added filter, spatial frequency 0.5 lp/mm at standard NPS showed a tendency to decrease after increase. Unused added filter, spatial frequency 0.5 lp/mm at standard NPS showed a certain NPS result value after decrease. DQE in 70 kVp / unuesd added filter(21 mm Al) / SID 150 cm that patial frequency 1.5 lp/mm at standard showed a tendency to decrease after certain value showed. Patial frequency in the rest quality of radiation was showed a tendency to decrease after increase. Results of evaluation of absorbed dose, air < water < muscle < bone in the order showed a tendency to increase. Based on the results of this study provide to basic data that present for the image quality evaluation method of a digital radiation imaging system in various the clinical condition.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.279-287
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• 2018

Sealants are an important element of modern architecture and serve as a building protection against weathering by providing barriers against ingress of moisture, air, and other materials. Exposure to a variety of environments often reduces lifespan due to changes in physical, chemical and mechanical characteristics, and UV, humidity, and temperature expansion are important issues that are directly related to durability. In this study, a combined deterioration test chamber was developed to simulate the environment of the open air as an instrument for verifying the durability of structural sealing materials indoors. In order to replicate special weather conditions, such as yellow dust, acid rain, and contamination by microorganisms, it was deemed impossible to replicate the outdoor environment by 100 %, and the results of the results of the results of the external exposure test of the structural sealant and the combined deterioration testing device. As a result of the displacement test of the outdoor exposure test, it was determined that the sealant was breaking apart and that it would be smooth, and the displacement would be up to three times greater than the initial material value of 1 year. The displacement test results of the combined deterioration test device show the tendency to deteriorate, decreasing the elasticity and tensile characteristics. In the case of denatured silicon, the current 400 cycles have been completed to confirm 12 months of degradation of the external exposure. The deformation of the test specimen cannot be verified with the naked eye, so it is considered that the conditions of the specimen are more stable than the silicon sealant. As a result of the outdoor exposure test, if the combined deterioration test device is structured and proposed in the relevant guidance or specification, the anticipated lifespan of 12 months in the actual use environment can be verified indoors and below 3 months later, economically.

• Korean Journal of Poultry Science
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• v.13 no.1
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• pp.41-48
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• 1986

In order to investigate the storage period of packed chicken meat in relation to the bacterial contamination of each processing part, a special grade poultry processing plant located at Dongdoochun-City, Gyeonggi-Do, was surveyed mainly in point of sanitary conditions. The results are summarized as follows. 1. processing room near reception and packing room next to shipping area showed the highest bacterial counts in air. 2. Equipments and instruments for slaughtering also showed a high degree of bacterial contamination even before the operation. This finding suggested that the possibility of the bacterial contamination of carcasses through equipments and instruments would be high, if the continuous sanitary control measures are not properly taken. 3. The bacterial count of scalding water was 3${\times}$10$\^$7/ for standard plate count and 4${\times}$10$\^$5/ for most probable number of coliform bacteria at 1 hour after the start of operation. These values were maintained until the completion of processing. 4. At the ending of chilling process, the bacterial counts of chilling water were 3.3 ${\times}$10$^4$ and 3.0${\times}$10$^3$for standard plate count, when the volume of water used per bird were 21 and 51, respectively. Bacterial contamination was further decreased about 10$\^$-3/-10$\^$-4/ times as the effective chlorine concentration in chilling water was maintained about 50 ppm. 5. An average standard plate count of the residual water In abdominal cavity of carcasses was 3.9${\times}$10$^4$immediate after chilling, however, it increased to 4.7${\times}$10$\^$7/ when the carcasses were packed and stored for 10 days at 4$^{\circ}C$. off-odour development was observed as the bacterial count was not less than 10$\^$6//$m\ell$ of the residual water of the packed carcasses. Data indicated that if the standard plate count of the residual water in abdominal cavity of carcasses was not less than l0$^4$immediate after chilling, the packed chicken meat would not be stored longer than 5 days at 4$^{\circ}C$.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.19-29
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• 1994

A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.628-635
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• 2014

The large amount of $CO_2$ emitted from mushrooms during incubation and developmental stages can be utilized in plant production systems as a $CO_2$ source. The objectives of this study were to measure the $CO_2$ emission and absorption rates of mushroom and lettuce, respectively, and to analyze the $CO_2$ concentrations at various ratios of mushroom and lettuce in a closed production system. The $CO_2$ emission rate of king oyster mushrooms (Pleurotus eryngii ( DC.) Qu$\acute{e}$l) and $CO_2$ absorption rate of lettuces (Lactuca sativa L. cv. Asia Heuk Romaine) were measured by using two closed acryl chambers ($1.0m{\times}0.8m{\times}0.5m$) in which indoor temperatures were maintained at $18^{\circ}C$ and $22^{\circ}C$, respectively. The lettuce was grown at a light intensity of PPF $340mol{\cdot}m^{-2}{\cdot}s^{-1}$ and with nutrient solution at EC $1.2dS{\cdot}m^{-1}$. The air was periodically circulated between the two chambers using a diaphragm pump. The $CO_2$ emission rate of the mushroom increased until the $15^{th}$ day after scratching (DAS) and then decreased. The rate also increased with increased indoor temperature. In particular, the $CO_2$ emission rate per fresh weight of fruit body increased by about 3.1 times after thinning compared to before thinning. In terms of $CO_2$ balance, the $CO_2$ emission rates from a bottle (950 mL) of the mushroom at 9, 12, and 14 DAS were equivalent to those of 3, 4.5, and 5.5 lettuce plants at 7, 10, and 12 DAT (days after transplanting), respectively. This work shows that balance in $CO_2$ concentration could be achieved using an appropriate ratio of the two crops in a closed production system.

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.17-23
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• 2002

The present study was carried out to investigate the effects of the maturation media such as a modified TCM-199 (mTCM-199) medium, modified Waymouth MB 752/1 (mWaymouth MB 752/1) medium or NCSU-23 medium on penetrability of pig oocytes by liquid boar sperm. Oocytes (30~40) were transferred into each well of a Nunc 4-well multidish containing 0.5 $m\ell$ maturation medium. When immature pig oocytes were cultured in mTCM-199, mWaymouth MB 752/1 and NCSU-23 maturation media for 44 h in 5% $CO_2$, in air at 38.5$^{\circ}C$, the germinal vesicle breakdown (CVBD) rates of the oocytes were 95.6, 94.1 and 94.9%, respectively, and the maturation rates (metaphase II) of oocytes were 92.5, 90.1 and 91.1%, respectively. No differences were observed among the maturation media. The spermrich portion of ejaculates with greater than 90% motile sperm were used in the experiment. The semen was cooled 22 to 24$^{\circ}C$ over 2 h period. The semen was diluted with Beltsville Thawing Solution (BTS) extender at room temperature to give 2$\times$10$^{8}$ sperm/$m\ell$ in 100 $m\ell$ plastic bottle. Liquid boar semen of 30 $m\ell$ in 100 $m\ell$ plastic bottle was kept at 17$^{\circ}C$ for 5 days. The sperm with greater than 70% motility after day 5 of storage were used for in-vitro fertilization (IVF). After 44 h maturation of immature oocytes, cumulus cells were removed and oocytes (30~40) coincubated far 6 h in 0.5 $m\ell$ mTCM-199 and mTBM fertilization media with 2$\times$1061$m\ell$ sperm concentration. At 6 h after IVF, oocytes were transferred into 0.5 $m\ell$ mTCM-199 and NCSU-23 culture media for further culture 6 or 42 h. Sperm penetration, polyspermy and male pronuclear formation of oocytes at 12 h after IVF, and developmental ability of oocytes at 48 h after IVF were evaluated. The oocytes in combination with NCSU-23 medium for maturation and mTBM medium for IVF increased male pronuclear formation (48.0%) compared to those in combination with mTCM-199 media for maturation and IVF, and mWaymouth MB 752il medium for maturation and mTCM-199 medium far IVF. The rates of cleaved embryos (2~4 cell stage) at 48 h after IVF were 24.1% in combination with mTCM-199 media for maturation, IVF and culture, 43.6% in combination with mWaymouth MB 75211 medium fur maturation and mTCM-199 media for IVF and culture, and 71.2% in combination with NCSU-23 medium for maturation, mTBM medium for IVF and NCSU-23 medium for culture. In conclusion, we found out the oocytes matured in vitro were fertilized by liquid boar sperm stored in BTS extender at 17$^{\circ}C$ for 5 days. We recommend the simple defined NCSU-23 medium for nuclear maturation, mTBM medium and liquid boar sperm for IVF, and NCSU-23 medium for embryo culture.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.113-124
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• 2005

Purpose : The using of endo-rectal balloon has proposed as optimal method that minimized the motion of prostate and the dose of rectum wall volume for treated prostate cancer patients, so we make the customized rectal balloon device. In this study, we analyzed the efficiency of the Self-customized rectal balloon in the aspects of its reproducibility. Materials and Methods : In 5 patients, for treatment planning, each patient was acquired CT slice images in state of with and without rectal balloon. Also they had CT scanning samely repeated third times in during radiation treatment (IMRT). In each case, we analyzed the deviation of rectal ballon position and verified the isodose distribution of rectum wall at closed prostate. Results : Using the rectal balloon, we minimized the planning target volume (PTV) by decreased the internal motion of prostate and overcome the dose limit of radiation therapy in prostate cancer by increased the gap between the rectum wall and high dose region. Conclusion : The using of rectal balloon, although, was reluctant to treat by patients. View a point of immobilization of prostate internal motion and dose escalation of GTV (gross tumor volume), its using consider large efficients for treated prostate cancer patients.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.35-43
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• 2005

Bioslurping combines the three remedial approaches of bioventing, vacuum-enhanced free-product recovery, and soil vapor extraction. Bioslurping is less effective in tight (low-permeability) soils. The greatest limitation to air permeability is excessive soil moisture. Optimum soil moisture is very soil-specific. Too much moisture can reduce air permeability of the soil and decrease its oxygen transfer capability. Too little moisture will inhibit microbial activity. So Modified Fenton reaction as chemical treatment which can overcome the weakness of Bioslurping was experimented for simultaneous treatment. Although the diesel removal efficiency of SVE process increased in proportion to applied vacuum pressure, SVE process was difficulty to remediation quickly semi- or non-volatile compounds absorbed soil strongly. And SVE process had variation of efficiency with distance from the extraction well and depth a air flow form of hemisphere centering around the well. Below 0.1 % hydrogen peroxide shows the potential of using hydrogen peroxide as oxygen source but the co-oxidation of chemical and biological treatment was impossible because of the low efficiency of Modified Fenton reaction at 0.1 % (wt) hydrogen peroxide. NTA was more efficiency than EDTA as chelating agent and diesel removal efficiency of Modified Fenton reaction increased in proportion to hydrogen peroxide concentration. Hexadecane as typical aliphatic compound was removed less than Toluene as aromatic compound because of its structural stability in Modified Fenton reaction. What minimum 10% hydrogen peroxide concentration has good remediation efficiency of diesel contaminated groundwater may show the potential use of Modified Fenton reaction after bioslurping treatment.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.11 no.2
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• pp.49-55
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• 2001

ZnO films were fabricated on p-type Si(100) wafer ITO glass and quartz glass by the sol-gel process using zinc acetate dihydrate as starting material. A homogeneous and stable solution was prepared by dissolving the zinc acetate dihydrate in a solution of 2-methoxyethanol and monoethanolamine (MEA). ZnO films were deposited by spin-coating at 2800 rpm for 25 s and were dried on a hot plate at $250^{\circ}C$ for 10 min. Crystallization of the films was carried out at $400^{\circ}C$~$800^{\circ}C$ for 1 h in air. X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), UV-vis transmittance spectroscopy, FTIR transmittance spectroscopy and Photoluminescence (PL) spectroscopy measurements have been used to study the structural and optical properties of the films. ZnO films highly oriented along the (002)plane were obtained. In all cases the films were found to be transparent (above 70%) in visible range with a sharp absorption edge at wavelengths of about 380nm, which is very close to the intrinsic band-gap of ZnO(3.2 eV). The low temperature band-edge photoluminescence revealed a complicated multi-line structure in terms of bound exciton complexes and the phonon replicas.

• Journal of the Korea Concrete Institute
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• v.15 no.1
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• pp.87-94
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• 2003

Construction plan and strength control have limitations in construction production field because it is difficult to predict the form removal strength and development of specified concrete strength. However, we can have reasonable construction plan and strength control if prediction of concrete strength is available. In this study, firstly, the newly proposed strength prediction model with maturity method was compared with the logistic model to test the adaptability. Secondly, the determination of time of form removal was verified through the new strength prediction model. As the results, it is found that investigation of the activation energy that are used to calculate equivalent age is necessary, and new strength prediction model was proved to be more accurate in the strength prediction than logistic model in the early age. Moreover, the use of new model was more reasonable because it has low SSE and high decisive factor. If we adopt new strength prediction model at construction field, we can expect the reduced period of work through the reduced time of form removal.