• Title/Summary/Keyword: 배합비

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Effect of γ-Aminobutyric Acid and Probiotics on the Egg Quality, Blood Parameter, Stress Level in Broiler Breeder (γ-Aminobutyric Acid 및 생균제 급여가 여름철 육용 종계의 계란 품질 및 혈액 성상에 미치는 영향)

  • Yoo Don, Ko;Ji Heon, Kim;Ha Guyn, Sung
    • Korean Journal of Poultry Science
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    • v.49 no.4
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    • pp.247-253
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    • 2022
  • This study was conducted to investigate the effects of γ-aminobutyric acid (GABA) and a probiotic mixture on egg quality, blood parameters, and corticosterone content in broiler breeder stock in summer in Korea. A total of 72 broiler breeders (Arbor Acres) at 49 weeks old were randomly divided into the following three groups of 24 heads each: control, GABA, and probiotics (1 × 108/g Bacillus licheniformis, 1 × 107/g Lactiplantibacillus plantaru, and 1 × 107/g Clostridium butyricum). The hens were fed a diet containing 50 mg of GABA/kg of feed and 0.1% probiotics for 6 weeks. Egg quality, blood parameters, and stress levels (corticosterone concentration) of the broiler breeders were evaluated. No significant differences were observed in the egg weight, albumen height, Haugh units, yolk color, shell thickness, or shell strength between the groups. There were no significant between-group differences in the blood biochemical profile, including total cholesterol, triglyceride, glucose, total protein, aspartate aminotransferase, alanine aminotransferase, albumin, and inorganic phosphorus concentrations. The corticosterone concentration was significantly lower in the GABA and probiotics groups than the control group (P < 0.05) at 6 weeks of age. In conclusion, these results suggest that dietary probiotics and GABA significantly improve the stress levels of broiler breeders in summer in Korea.

Study on Composition and Fertilization of Feces from Laying Hens Fed Dietary Phytase (인분해효소를 급여한 산란계에서 배출되는 계분의 성상과 비료화에 관한 연구)

  • Lim, Chun Ik;Kim, Seong Jun;Kim, Ju Eun;Song, Seong Eun;Lee, Deog Bae;Ryu, Kyeong Seon
    • Korean Journal of Poultry Science
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    • v.49 no.1
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    • pp.25-32
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    • 2022
  • This study was conducted to produce a nutrient-balanced complex fertilizer using compost from laying hens fed with phytase levels. A total of 30 laying hens were randomly assigned in individual cages. The dietary treatments were fed from 51 to 60 wks of age, and included a phytase; 0, 1,000, and 2,000 FTU/kg in basal diets. Fresh feed (110 g) and drinking water were supplied to the laying hens every day. Feces from hens were collected daily and analyzed for N, P2O5, and K2O after compost maturity. This result showed there was no difference on the fecal excretion per feed intake of laying hens supplemented with phytase levels in the diets. On the other hand, the excretions of dried feces, N, P2O5, and K2O were significantly (P<0.05) reduced in 2,000 FTU/kg treatment than 0, 1,000 FTU/kg treatments. There was no difference on the compost composition and nutrient contents in compound fertilizer using compost from hens fed dietary phytase levels. However, compost content in the fertilizer was 69.6~71.6% when compost of 25~30% moisture content was used, and 13.0~47.1% at compost of 40~60% moisture content. As a result of this study, it was confirmed that hen's compost controlled moisture content could be produced as a nutrient-balanced compound fertilizer.

Evaluation of Chloride Absorption in GGBS Concrete by Impedance Measurements (임피던스 측정을 통한 GGBS 콘크리트의 염화물 흡수 평가)

  • Kim, Jaehwan;Cho, Han-Min;You, Young-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.6
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    • pp.230-237
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    • 2022
  • It is essential that service life of reinforced concrete structures in economic and safety aspects should be secured. It is well-known that chloride attack is a typical deterioration mechanism in field concrete structures. To prevent serious accidents like collapse, many studies have been conducted to increase resistance of chloride ingress using concrete mixed with GGBS. The usage of GGBS concrete is nowadays mandatory. Since most concretes in the field are unsaturated, study regarding chloride absorption is necessary, but many studies have focused on the chloride diffusion phenomenon. Methods for evaluating chloride absorption are cost and improper in the field. It is necessary to develop a simple method for evaluating chloride absorption in practice. This study evaluated resistance of chloride ingress in GGBS concretes with impedance measurement and absorption test. From the results, it was confirmed that the contents of absorbed chloride were linearly correlated with the measured electrical resistivities (or conductivities) in the concrete. At the end of the test, the electrical conductivities were 250.8 S/m (w/b=0.4) and 303.1 S/m (w/b=0.6) for PC concretes, and 2.6 S/m (w/b=0.4) and 64.4 S/m (w/b=0.6) for GGBS concretes, respectively. Considering influencing factors for chloride absorption and impedance measurement, chloride ingress into concrete is mainly affected by pore structures due to replacement of GGBS. Especially, formations of pore structure are different with binder, thereby binders should be considered in building reinforced concrete structures exposed to chloride environments.

The study on Coal Spontaneous Ignition Prevention using Safety Materials of Food and Cosmetics (식품과 화장품의 안전 소재를 이용한 석탄 자연발화 억제에 대한 연구)

  • Jun, Soo-Man;Kim, Young-Hee
    • Journal of the Korean Applied Science and Technology
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    • v.39 no.2
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    • pp.368-376
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    • 2022
  • Spontaneous ignition occurs in industrial sites or anywhere in our lives, and is a phenomenon in which a substance ignites itself without an ignition source in the atmosphere. As the rate of chemical reaction increases, the heat generated increases, and the risk of spontaneous ignition increases. In this study, safe raw materials used for food and cosmetics were mixed to prepare coal spontaneous ignition prevention agents specifically among various spontaneous ignition phenomena. The effect of suppressing spontaneous combustion of coal was confirmed through lab and field tests with low-calorie, low-grade coal from Indonesia. As a result of the outdoor field test, the ignition prevention agent manufactured in this study compared with the control group(Fire after 90 days) showed excellent ignition inhibitors for more than 120 days. In addition, CO concentration control was confirmed by comparing the concentration of carbon monoxide for 50 days at the indoor coal yard. It was confirmed that the results were better than the comparative group coal and the existing anti-firing method. In addition, the possibility of coal fire prevention agents for indoor coal farms will be applied from 2024 was confirmed by studying the environment and safety of workers' working environments through official test such as soil and water quality test, MSDS of coal fire prevention agents in consideration of working workers, water quality, and eye irritation tests.

An Experimental Study for Characteristics Evaluation of Cement Mortar Using Infrared Thermography Technique (적외선 화상기법을 이용한 시멘트 모르타르 특성의 실험적 평가)

  • Kwon, Seung-Jun;Maria, Q. Feng
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.1A
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    • pp.53-59
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    • 2010
  • Recently, NDTs (Non-Destructive Techniques) using infrared camera are widely studied for detection of damage and void in RC (reinforced concrete) structures and they are also considered as an effective techniques for maintenance of infrastructures. The temperature on concrete surface depends on material and thermal properties such as specific heat, thermal conductivity, and thermal diffusion coefficient. Different porosity on cement mortar due to different mixture proportions can show different heat behavior in cooling stage. The porosity can affect physical and durability properties like strength and chloride diffusion coefficient as well. In this paper, active thermography which uses flash for heat induction is utilized and thermal characteristics on surface are evaluated. Samples of cement mortar with W/C (water to cement ratio) of 0.55 and 0.65 are prepared and physical properties like porosity, compressive strength, and chloride diffusion coefficient are evaluated. Then infrared thermography technique is carried out in a constant room condition (temperature $20{\sim}22^{\circ}C$ and relative humidity 55-60%). The mortar samples with higher porosity shows higher residual temperature at the cooling stage and also shows reduced critical time which shows constant temperature due to back wall effect. Furthermore, simple equation for critical time of back wall effect is suggested with porosity and experimental constants. These characteristics indicate the applicability of infrared thermography as an NDT for quality assessment of cement based composite like concrete. Physical properties and thermal behavior in cement mortar with different porosity are analyzed in discussed in this paper.

The Performance Evaluation of In-situ Carbonation Mortar Using Gaseous CO2 (기체 CO2를 사용한 In-situ 탄산화 모르타르 성능평가)

  • Changgun Park;Deukhyun Ryu;Seongwoo Choi;Kwangwoo Wi;Seungmin Lim
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.3
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    • pp.226-233
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    • 2023
  • In this study, two phases were conducted to investigate the direct injection of gaseous CO2 into cement mortar. The aim was to advance carbon capture, utilization, and storage (CCUS) technology by harnessing industrial waste CO2 from the domestic ready-mixed concrete industry. In the first phase, the factors influencing the physical properties of cement mortar when using gaseous CO2 were identified. This included a review of materials to achieve physical properties comparable to a reference formulation. As a result of this phase, it was confirmed that traditional approaches, such as adjusting the water-to-cement ratio, had limitations in achieving the desired physical properties. Consequently, the second phase focused on the optimization of CO2-injected mortar. This involved studying the CO2 application and mixing method for cement mortar. Changes in properties were observed when gaseous CO2 was injected into the mortar. The optimal injection quantity and time to enhance the compressive strength of mortar were determinded. As a result, this study indicated that an extra mixing time exceeding 120 seconds was necessary, compared to conventional mortar. The optimal CO2 injection rate was identified as 0.1 to 0.2 % by weight of cement, taking both flowability and compressive strength performance into account. Increasing the CO2 injection time did not further enhance strength. For this approach to be employed as a CCUS technology, additional studies are required, including a microstructural analysis evaluating the amount of immobilized CO2.

The Buildability and Strength Properties of 3D Printed Concrete in the Air and Underwater Environment (수중과 기중환경에서 출력된 3D 프린팅 콘크리트의 적층성능 및 강도 특성 분석)

  • Eun-A Seo;Ho-Jae Lee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.28 no.2
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    • pp.35-42
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    • 2024
  • This study evaluated the buildability and mechanical properties of 3DP concrete printed in air and underwater environments. Buildability was evaluated by green strength test on fresh concrete and height and deflection immediately and 1 hour after printing. The green compressive strength of the concrete was 5.0 kPa after 30 minutes and 7.9 kPa after 3 hours, an increase of 1.6 times the initial strength. The total height of the laminated parts met the design height regardless of the printing environment. The amount of deflection in air and under water 1 hour after printing was 1 mm and 0.2 mm, respectively, indicating a small amount of deflection under water. The apparent density of the sample appeared in the order of A-M > A-P > UW-P. This is believed to be because a large amount of air is mixed into the concrete during the printing process, and water infiltrates during the underwater printing process. The compressive strength ratio of UW-P/A-P was 0.86 at 1 day, but the compressive strength of the underwater printed concrete was high from 7 days.

Application of Time Domain Reflectometry to Estimate Curing Process of Cementitious Grout (시계열반사계를 이용한 시멘트계열 지반보강재의 양생과정 평가)

  • Jun, Minu;Cho, Hyunmuk;Lee, Eun Sang;Hong, Won-Taek
    • Journal of the Korean Geotechnical Society
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    • v.40 no.3
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    • pp.85-91
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    • 2024
  • To realize stable use of ground treated with cementitious materials, the curing process must be evaluated. In this study, a time domain reflectometry (TDR) measurement system was employed to evaluate the curing process of cementitious grout based on the electromagnetic property. A coated probe was manufactured to prevent electrical connection between the electrodes by the electrically conductive cementitious grout, and a calibration process was performed to estimate the actual relative permittivity using the coated probe. To assess the curing process of cementitious grout using the TDR measurement system, cementitious grout with added retarder was prepared with a water-to-cement ratio of 45%. A preliminary measurement was conducted immediately after pouring the cementitious grout into the mold to test the applicability of the coated probe, and TDR signals and relative permittivity were measured at 3~288 hours of curing time. The experimental results demonstrate that the relative permittivity of the cementitious grout immediately after pouring was greater than 100, decreased rapidly over time, and converged to approximately 13.8 at 144 hours, which is considered the fully cured time. This findings of this study demonstrate that the TDR measurement system with a coated probe is applicable to electrically conductive materials. In addition, the TDR measurement system can be used effectively to monitor the curing process of cementitious grout based on electromagnetic properties.

Physical Properties of Cement Using Slag as Raw Mix of Clinker (슬래그를 클링커 혼합원료로 사용한 시멘트의 물리적 특성)

  • Young-Jun Lee;Do-young Kwon;Bilguun Mend;Yong-Sik Chu
    • Resources Recycling
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    • v.33 no.3
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    • pp.12-20
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    • 2024
  • The global cement industry emits approximately 2.9 billion tons of greenhouse gases, of which 1.74-1.89 billion tons are emitted from limestone, which is the main raw material for clinkers. Therefore, the feasibility of using slag, a non-carbonated CaO-based raw material, must be investigated, and the physical properties of cement must be considered. In this study, the mixing ratios of the raw mix and properties of cement were analyzed. The CaCO3 replacement ratio was limited when one type of slag was used; however, when the mixed slag was utilized, the CaCO3 replacement ratio increased by more than 12 %. The compressive strength of the slag-incorporated cement was lower than that of Ordinary Portland Cement (OPC). Therefore, the lime saturation factor (LSF) of the raw mix and fineness of the cement were increased to improve the compressive strength. The compressive strength of cement with improved fineness was similar to that of OPC for a CaCO3 replacement ratio of up to 6 %, and it decreased as the CaCO3 replacement ratio was increased to 9 %. When both fineness and LSF were increased, the compressive strength and flow value of the cement with a CaCO3 replacement ratio of 12 % were similar to that of OPC.

Spalling Properties of the High Strength Concrete Containing PP Fiber Subjected to Fire Mixture Factors and Drying Condition (배합요인 및 건조상태 변화에 따른 PP섬유 혼입 고강도 콘크리트의 폭렬특성)

  • Han, Cheon-Goo;Han, Min-Cheol;Song, Yong-Won
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.4
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    • pp.115-122
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    • 2008
  • This paper is to investigate the affecting factors on spalling of the high strength concrete including W/B, air content and moisture condition as well as PP fiber contents subjected to fire. An increase with 0.05% of PP fiber resulted in a reduction of slump flow by as much as 11%. Ten percent of air contents due to excessive amounts of AE agent does not lead to variance of slump flow, regardless of PP fiber content. For the effect of the compressive strength, high strength concrete with 15, 25 and 35% of W/B gained 60 MPa~100 MPa of the compressive strength. High strength concrete with H-air had half of compressive strength of that with L-air due to large amount of air. Fire test was conducted in accordance with KS F 2257-1 for 1 hour. Spalling did not occur with all specimens containing more than 0.10% of PP fiber except those with 15% of W/B. Moreover, it is interesting to note that the specimens with more than 10% of air content and with oven dried condition, respectively, had no spalling even if the content of PP fiber is 0.05 vol.%.