본 시험은 요소의 시비수준을 0, 100, 200 kg/ha로 하고 가축분뇨의 시용량을 질소함량을 기준으로 0. 40, 80, 160 kg/ha로 했을 때 영년 Orchardgrass 초지의 생산성과 토양중 NO-N 함량에 미치는 영향에 대하여 연구한 결과는 다음과 같다. 1 초지의 생산성은 요소 N 시용량이 100 kg/ha 수준까지에서는 분뇨 N의 시용량의 증가에 따라 유의적인 증가를 보여 주었으나 요소 N의 시용량이 200 kg/ha 수준에서의 분

본 시험은 방목이용 초지에서 액상구비(액비) 시용시 가축기호성과 초지 이용효율을 증진시키고자 액비 시용시기를 방목직후(평균 목초 초장 7.5cm), 방목 후 5일째(13.6cm), 방목 후 10일째(18.5cm), 방목 후 15일째(23.5cm)로 달리하고, 액비무시용구를 대조구로 하여 실시되었다. 연간 액비 시용량은 40㎥/ha로 봄철 2회, 여름철 1회, 가을철 1회로 4회 균등 분시하였으며, 전 시험구에서 연간 시비량은 질소 280, 인산 200,

With a purpose of finding out the effects of cattle slurry application on thc nutrient contents of herbages and energy productivity in grassland, a field experiment was conducted with two times and five levels of cattle slurry application. The experimenta

With a purpose of finding out the effects of cattle slurry applicatioin on the dry matter yield, yield component, and botanical composition in the mixed sward, a field experiment was conducted with two times and five levels of cattle slurry application. T

This study aimed to investigate the effect of amino acid additives to weaned piglet diets on the pH and volatile fatty acids of pig slurries. A total of 135 weaned 22 -day-old piglets (Yorkshire x Landrace x Duroc) were used in this 56-d study. The three dietary treatments were as follows: (1) Control as a basal diet, (2) 1% amino acid additive and (3) 2% amino acid additive. Both pH and acetic acid values at 71 and 78 days were significantly different in all treatment groups (p<0.05). In addition, significant differences in propionic acid values were observed among treatment groups at 64 and 78 days (p<0.05). However, pH, acetic acid, and propionic acid values did not differ between 1% and 2% amino acid treatment groups. In conclusion, adding 1% and 2% amino acid to weaned piglet diets reduced the pH, acetic acid and propionic acid contents of pig slurries by acting as a probiotic. This may help formulate increase management strategies for improving the pig housing environment.

The aim of this study was to investigate the effect of manure additives mixed with probiotics and zeolite on harmful gas production generated by pig slurry. A total of 180 crossbred pigs ([Yorkshire x Land race] x Duroc, live weight 70±3.21 kg) were allotted to a completely randomized design with 3 treatments and 3 replications (20 heads per replicate). The treatments consisted of 0% (control), 0.05% (T1), or 1% (T2) of manure additives mixed with probiotics and zeolite. Manure additives were added weekly to pig slurry pits (2 m × 4.5 m × 1.2 m) on a volumetric basis. For ammonia measured at both 10 cm and 90 cm above the pig slurry pit, a statistical significance (p<0.05) was found in probiotics and zeolite-treated manure additives at weeks 1 – 3, except for week 0. In addition, hydrogen sulfide levels measured at 10 cm above the pig slurry pit were not affected by the manure additive at weeks 0 and 1, but showed a significant statistical difference at weeks 2 and 3 (p<0.05). Therefore, supplementing pig slurry with 0.05% and 0.1% manure additives mixed with probiotics and zeolite was found to be effective in reducing environmental pollution in pig facilities.

우리나라의 축산업은 1980년대 이후로 전업화 및 대규모화가 진행됨에 따라 급격히 성장하였으나, 이와 동시에 늘어나는 가축분뇨의 처리문제가 크게 대두 되었다. 2016년 국내 가축분뇨 발생량은 46,988 천 톤에 해당하며, 이중 양돈 분뇨가 18,464 천 톤으로 전체 발생량의 42.3%를 차지하였다. 일반적으로 국내 대부분의 양돈 농가는 슬러리 형태의 돈사 구조이며, 발생하는 분뇨의 성상은 액상 형태이다. 슬러리(액상 가축분뇨)는 액비화 시, 공기를 주입하여 호기성 미생물의 유기물 분해를 유도하기 때문에 액비화 효율을 높이기 위해서는 폭기 방법에 대한 연구가 선결되어야 한다. 따라서 본 연구는 액비화 효율 개선을 위해 기존 폭기 방식과 순산소(산소농도 95%) 처리 시 액비의 이화학 특성 변화의 차이를 분석하여 향후 양질 액비를 만드는 기술 개발의 기초자료로 이용하고자 수행하였다. 시험에 이용된 반응기는 폴리에틸렌(PE) 소재로 약 1.5m3 규모로 제작 하였으며, 순산소에 의한 액비화 효율을 평가하기 위해 무폭기(대조구), 일반폭기, 순산소로 처리구를 설정하였다. 일반 폭기의 경우 ‘가축분뇨 처리시설 표준설계도’에 근거하여 반응기 내에 약 30 L/m3･min의 공기를 주입하도록 설계하였으며, 순산소 처리구는 6 L/m3･min의 공기를 주입한 후 비교 실험을 수행하였다. 액비화 과정 중 온도변화를 관찰한 결과, 액비화 개시 온도는 25℃였으며, 실험 개시 48시간 후에 순산소 처리구의 온도가 47℃ 일반폭기가 32℃ 비폭기가 30℃로 상승하여 순산소 처리구의 유기물 분해가 더 빨리 진행되는 것을 관찰할 수 있었다. 액비화 과정 중 암모니아 발생농도를 관찰한 결과, 순산소 처리구의 경우 액비화 개시 5일 이후에 는 160 ppm으로 가장 높은 암모니아 발생량을 관찰할 수 있었으나, 점차 감소하여 20일 이후에는 검출되지 않았다. 하지만 일반 폭기구의 경우 액비화 개시 20일 까지 약 440 ppm의 암모니아 농도가 검출되었다. 일반적으로 순산소는 유기성 질소의 질산화를 촉진시켜 암모니아 기화를 방지한다고 알려져 있으며, 본 실험에서도 이와 같은 결과를 관찰할 수 있었다. 이를 액비 내 총켈달 질소(TKN)의 농도 변화와 비교 분석한 결과, 실험이 끝난 후 순산소 처리구의 액비 내 질소함량은 0.078%, 일반 폭기구는 0.059%로 조사되어 위 실험과 일치하는 결과를 얻을 수 있었다.

본 논문은 SIFCON으로 제작된 휨부재의 휨거동에 대한 실험적·해석적 연구결과를 제시한다. 우선, 12개의 SIFCON 보에 대한 휨실험을 실시하고 휨거동을 평가하였다. 실험변수로는 강섬유 종류, 인장철근 유·무, 단면의 높이를 고려하였다. Type-A 강섬유보다 뽐힘저항성이 우수한 Type-B 강섬유를 사용한 시험체는 전단파괴가 발생하지 않고 휨파괴 거동을 보였으며, 강섬유 형상비는 인장철근을 사용하지 않는 SIFCON 보의 거동에 큰 영향을 주었으나 인장철근을 갖는 SIFCON 보의 거동에 대해서는 그 영향이 매우 미미하게 나타났다. 추가적으로 본연구에서는 SIFCON에 대한 휨강도 예측식을 제시하였다. 휨강도 예측값에 대한 실험값의 비의 평균과 표준편차가 각각 1.02와 0.04로 나타나 휨강도 예측식은 SIFCON 보의 설계 및 성능 평가에 유용하게 사용될 수 있을 것으로 생각된다.

In order to verify the strength of slurry shotcrete compared to existing shotcrete, The results were analyzed and evaluated.

The ultimate load of beam reinforced with polymer cement slurry(PCS)-coated rebar is a little lower than that of un-coated rebar, and almost the same as that epoxy-coated rebar. In special, that using EVA 50% with is in range of 97.0% of un-coated rebar. In this study, it is also apparent that PCS-coated rebar can replace epoxy-coated rebar to solve the corrosion problem in marine construction field.

This study is to primarily investigate the consistency and compressive strength of an in-fill slurry of the SIFCON-based HPFRCC according to the mixing time. The mixing time considered were 10, 15 and 20 minutes.

The field test was conducted for the shotcrete construction using a slurry-type accelerator. Check the efficiency of the equipment and the accelerator was determined using the discharge amount for the accelerator ratio optimization. As a result, the efficiency of a slurry quick-setting admixture mix shotcrete and discharge rate results were evaluated to be excellent.

Bond strength of PCS-coated rebar is better than that of uncoated rebar and epoxy-coated rebar. It is also high bond strength at curing ages of 7-day or less, and coating thicknesses of 75 μm and 100 μm. The maximum bond strength of PCS-coated rebar at curing age of 3-hour is almost same as that of curing age of 1-day and 7-day. The maximum bond strength of PCS-coated rebar with EVA at polymer-cement ratio of 100%, and coating thickness of 100 μm is about 1.23 and 1.29 times respectively, the strength of uncoated rebar and epoxy-coated rebar. It is apparent that the curing age, coating thickness and polymer cement ratio are very important factors to improve the bond strength of PCS-coated rebar to cement concrete. We can havebasic information that it can replace epoxy coated rebar by the PCS-coated rebar with curing age at 3-hour and coating thickness of 100 μm.

본 연구는 SIFCON 형태의 고성능 강섬유보강 시멘트 복합체의 섬유혼입률에 따른 휨실험을 수행하였고, 실험결과를 바탕으로 휨성능을 평가하였다. 슬러리를 충전하는 형태로 일반 섬유보강시멘트와 달리 높은 섬유혼입률을 확보할 수 있는 장점을 가지고 있다. 주요 실험변수는 섬유혼입률 8.0%, 7.5%, 7.0%, 6.5% 및 6.0% 이며, 각 변수에 대한 휨강도 및 휨인성 특성을 분석하였다. 그 결과, 높은 섬유혼입률로 인하여 초기균열 발생 이후에도 계속적으로 하중이 증가하였으며, 최대강도 이후 충분한 잔류강도를 확보하였다. 또한 최대 50MPa 수준의 높은 휨강도를 발현하였으며, 섬유혼입률에 따른 휨강도 및 휨인성은 비례하여 증가하는 경향으로 나타났다.

The ultimate load of beam reinforced with polymer cement slurry(PCS)-coated rebar that is developed to replace the epoxy coated rebar having many defects is almost the same as that using plain rebar, and is higher than that of epoxy-coated rebar. In special, that using EVA 100% with ultra high early strength cement is a little bigger than that using plain rebar. In this study, it is also apparent that PCS-coated rebar can replace epoxy-coated rebar to solve the corrosion problem in marine construction field.

In general, polymer cement slurry(PCS) that is made from organic polymer dispersion and cement has good adhesion to steel and cement concrete. Bond strength of PCS-coated rebar is better than that of plain rebar and epoxy-coated rebar. The maximum bond strength of PCS-coated rebar at curing age of 1-day or 3-hour is almost same as that of curing age of 7-day and 28-day. It is possible that PCS-coated rebar with coating thickness of 100㎛ at curing age of 1-day and 3-hour can replace epoxy-coated rebar. It is also apparent that the choice of curing age and coating thickness is very important to improve the bond strength of PCS-coated rebar to cement concrete.

This study aimed to evaluate the effects of probiotics as manure additives on pathogen, mineral, carbon dioxide and methane emissions in pig slurry as a function of time and provide information about the importance of pig slurry management to pig producers. An experiment was a completely randomized design and four treatments: CON: no treatment (5 kg pig slurry), T1: 5 kg pig slurry + 0.2% bacillus subtilis, T2: 5 kg pig slurry + 0.2% yeast, T3: 5 kg pig slurry + 0.2% actinomycetales. All treatments were replicated three times. The results information that is analyzed includes the following: First, in spite of the lack of statistically significant differences, pH values and carbon dioxide were lowered (P < 0.05) in all probiotic treatments compared with the controls as a function of time. Second, all probiotic treatments had no effect on Salmonella enterica, mineral, and methane emission. The results of this study indicated that addition of 0.2% probiotic to pig slurry resulted in lower pH and carbon dioxide emissions, and carbon dioxide and methane emitted from pig slurry is not listed as noxious gases.

A rapid and simple method for the quantitative determination of volatile fatty acids (VFAs; propionic acid, n-butyric acid, i-valeric acid and n-valeric acid) and indoles (phenol, p-cresol, 4-ethyl phenol, indole and skatole) in pig slurry and dog excrement using solid-phase micro-extraction (SPME) coupled to gas chromatography was evaluated. 50/30 ㎛ DVB/CAR/PDMS (Divinylbenzene/Carboxen/Polydimethylsiloxane) fiber was used to extract the target compounds in aqueous media. Sample amount and adsorption time was standardized for the routine analysis. Detection limits were from 0.11 to 0.15 ㎍/L for VFAs and from 0.12 to 0.28 ㎍/L for indoles and the correlations observed (R2) were 0.975～1.000. This method was applied to the pig slurry, fertilizer, compost and dog excrement. In nearly all cases, the indoles were detected in concentrations of higher than their limits of detection (DOLs). But the VFAs in swine manure were below their DOLs.

This study evaluated compressive strength on the slurry for HPFRCC using blast- furnace slag with various blain as a basic study for developing alternative technology of the existing HPFRCC.

High Performance Fiber Reinforced Cementitious Composites (HPFRCC) provides high fracture energy absorption capacity, as well as high strength, being one of the most promising new construction materials. This study is a part of the research works to develop a blast/impact protection material for existing structures. High flow slurry can be used as a cementitious matrix to fill the HPFRCC. A new type of test method was adopted herein, called J-Fiber Penetration Test, to investigate the ability of cement slurry to flow through the fiber mass.