• Asian-Australasian Journal of Animal Sciences
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• 제12권2호
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• pp.271-281
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• 1999

The cost of production of high quality pork is compensated by high returns, but constraints by the market are increasing. A few opportunities to maintain and improve pork quality by dietary means are presented. The healthy value of pork is a prerequisite. A careful control of suppliers and preservation of feeds are essential to protect pork against presence of contaminants from the feed. The feeding level and some dietary components modify the partition of the dietary energy into different pig tissues and chemical components of pork, affecting the hygienic and nutritional value, tenderness and taste. It is difficult to transfer a nutrient from the diet to pork, if the requirements. for growth are satisfied. Fatty acids and Vitamin E are the most studied exceptions. There is some evidence that iron and selenium contents can be affected too. Varying the content of a nutrient frequently changes sensorial and technological properties of pork. The addition of oils improves the acidic profile of depot fats, but the effect on phospholipid composition is not well studied and negative effects on oxidability and consistency of meat products are observed. Vitamin E can improve many healthy and sensorial characteristics, but its effect is clearer when the meat is stressed or manipulated.

• Environmental Engineering Research
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• 제18권4호
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• pp.267-276
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• 2013

This study presents a comparison of different protocols for the synthesis of iron-loaded zeolites, and the results of their application, as well as that of zeolite-A (Z-A), to the removal of ammonium and phosphate from aqueous media. Zeolites prepared by three methods were evaluated: iron-incorporated zeolites (IIZ), iron-exchanged zeolites (IEZ), and iron-calcined zeolites (ICZ). The optimal iron content for preparing of IIZ, as determined via scanning electron microscopy and X-ray photoelectron spectroscopy analyses, expressed as molar ratio of $SiO_2:Al_2O_3:Fe$, was below 0.05. Ammonia removal revealed that the iron-loaded zeolites have a higher removal capacity than that of Z-A due, not only to ion-exchange phenomena, but also via adsorption. Greater phosphate removal was achieved with IEZ than with ICZ; additionally, no sludge production was observed in this heterogeneous reaction, even though the coagulation process is generally accompanied by the production of a large amount of undesired chemical sludge. This study demonstrates that the developed synthetic iron-loaded zeolites can be applied as a heterogeneous nutrient-removal materials with no sludge production.

• 한국토양비료학회지
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• 제36권5호
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• pp.344-355
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• 2003

우리나라는 농경지 단위면적 당 화학비료 시용량이 높은 국가로 분류되고 있다. 화학비료 시용량 저감을 위해 정부에서는 1990년 들어 다양한 정책적 지원을 지속해오고 있다. 본 연구에서는 1999년 전국의 시군을 대상으로 농가비료이용실태를 작물별, 농지이용유형별로 조사하여 1992년 농가비료이용실태와 비교하였다. 주요 작물에 대한 유기질비료의 평균 시용율은 최근 크게 감소하였으나, 시설재배지와 밭토양에서의 유기물 시용율은 1992년과 큰 변화가 없었다. 농가포장의 화학비료 시용율은 대부분의 곡류와 채소작물에서 다소 감소하는 경향을 보였다. 화학비료 중 질소질 비료 시용율 감소는 거의 없었으며, 인산과 칼리질 비료의 시용량 감소가 전체 화학비료 시용량에 감소에 영향을 주었다. 이러한 화학비료 시용량 감소에도 불구하고 대부분의 작물에 대한 비료사용량은 추천 시비량을 크게 초과하고 있었다. 양분 투입량과 회수량간 차이를 이용하여 계산된 양분수지를 계산한 결과, 질소의 과잉시용은 거의 감소되지 않고 있으나, 인산과 칼리의 시용량은 1992년에 비해 1999년 각각 21%와 13% 감소되었다. 결과적으로 정부와 관련기관의 적극적인 홍보에도 불구하고 1999년 현재까지 농가포장에서는 비료가 과잉시용되고 있었으며, 이를 개선하기 위해 토양검정치를 기준으로 산정한 추천시비량 수준으로 양분 시용량의 저감을 위한 효과적인 기술지원과 지도관리가 필요할 것으로 판단되었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2002년도 춘계 학술대회지
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• pp.19-27
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• 2002

Development of crops with high quality as well as various beneficial functions is necessary to satisfy consumers being interested in their health and to enhance a competitiveness in the international market of agricultural products. What we have achieved so far from our research on crop quality was not sufficient since we often neglected sensory feature of crop products such as eating quality but in many cases, we put more emphases on nutrient contents, physico-chemical properties, and out-appearing features of the products. Therefore developments of sensory elements and technique for evaluation with a priority given to eating quality of each of an individual crop are important and very urgent to be solved in Korea. An endeavor to develop bioactive crops is necessary and resonable but aspects of both productivity and economy with a special emphasis on the original purposes such as production of energy and nutrient for human life must be considered. The development of more concrete ideas for crop functionality is essential before any research goes further.

• Environmental Engineering Research
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• 제21권4호
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• pp.401-408
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• 2016

The aim of this study was to evaluate the biomass and lipid production of Chlorella vulgaris and its nutrient removal capability for treatment of brewery wastewater effluent. The results indicate that the maximum biochemical oxygen demand (BOD) (91.43%) and chemical oxygen demand (COD) (83.11%) were removed by C. vulgaris with aeration in the absence of light. A maximum of 0.917 g/L of dry biomass was obtained with aeration in the dark conditions, which also demonstrated the highest amount of unsaturated fatty acids at 83.22%. However, the removal of total nitrogen (TN) and total phosphorus (TP) with these aeration and light conditions was 9.7% and 11.86% greater than that of other conditions. The removal of BOD and COD and the production of biomass and lipids with aeration in the dark and the TN and TP removal with aeration and light were more effective than other conditions in the brewery wastewater effluent in the presence of C. vulgaris.

• Journal of Biosystems Engineering
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• 제32권1호
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• pp.37-43
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• 2007

This study was carried out to investigate the applicability of PVC membrane-based ion-selective electrodes for macronutrients (K, Ca, and N) by measuring of potassium, calcium, nitrate ions in hydroponic nutrient solution. The capabilities of two ion-selective membranes with varying chemical compositions for each ion were evaluated in terms of sensitivity, selectivity, and lifetime to choose sensing elements suitable for measuring typical ranges of nutrient concentrations in hydroponic solutions. The selected calcium and nitrate ion-selective membranes showed effectively sensitive responses to calcium and nitrate ions with lifetimes of 25 and 15 days, respectively. The addition of a cation additive to the potassium membrane cocktail allowed its sensitivity to be increased whereas its lifetime was reduced from 30 days to 10 days.

• 한국작물학회지
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• 제47권
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• pp.1-14
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• 2002

Development of crops with high quality as well as various beneficial functions is necessary to satisfy consumers being interested in their health and to enhance a competitiveness in the international market of agricultural products. What we have achieved so far from our research on crop quality was not sufficient since we often neglected sensory feature of crop products such as eating quality but in many cases, we put more emphases on nutrient contents, physico-chemical properties, and out-appearing features of the products. Therefore developments of sensory elements and technique for evaluation with a priority given to eating quality of each of an individual crop are important and very urgent to be solved in Korea. An endeavor to develop bioactive crops is necessary and resonable but aspects of both productivity and economy with a special emphasis on the original purposes such as production of energy and nutrient for human life must be considered. The development of more concrete ideas for crop functionality is essential before any research goes further.

• 대한환경공학회지
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• 제32권1호
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• pp.1-8
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• 2010

하구형 호수인 아산호(평택호)에서 방조제 근처의 A지점과 상류 하천이 유입되는 B지점을 선정하여, 퇴적물 성상과 퇴적물에서 발생하는 영양염 용출량을 측정함으로써 퇴적물이 아산호 수질에 미치는 영향에 대해 살펴보았다. 아산호의 퇴적물은 sandy loam으로 이루어져있고, 대부분의 인이 Nonapatite-P(64.7%)의 형태로 존재하고 있으므로, 수중의 pH 상승이나 혐기성 상태로의 전환 등에 의해 다량의 인이 퇴적물에서 용출되어 수체의 부영양화에 영향을 줄 수 있는 가능성이 있다. 4월이 6월에 비해 용출율이 높게 나타남을 알 수 있었다. 방조제 근처인 A지점에서는 질소, 유입지천의 합류점인 B지점에서는 인의 용출이 활발히 일어났다. 용출율과 퇴적물의 표면적을 이용해 일일 평균 용출량을 계산해보면, TN는 6,609 kg/d, TP은 3,877 kg/d로 유입지천으로부터 유입되는 TN의 93,616 kg/d 중 7.06%, TP의 17,590 kg/d 중 22.04%에 해당되는 값으로, 아산호의 퇴적물이 저수지 수질에 미칠 영향은 적다고 볼 수 있다.

• 한국유기농업학회지
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• 제17권3호
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• pp.357-370
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• 2009

본 연구는 돈분뇨 여과 및 농축액비를 이용한 양액재배의 가능성을 검토하기 위하여 여과액비와 농축액비와 부산물, 양액 혼합처리가 토마토 생육에 미치는 영향을 검토하였다. 퇴비화 과정 중 과수분 상태에서 배출되는 퇴비단 여과액비와 막분리 처리과정에서 한외 여과막을 통과하고 역삼투막 처리에서 역류되어 나오는 돈슬러리 농축액비를 공시재료로 하였다. 본 연구는 질소함량을 기준으로 액비와 부산물, 양액의 혼합하는 처리구를 두어 전기전도도와 pH를 조정하여 토마토의 양액재배를 실시한 결과를 요약하면 다음과 같다. 1. 여과액비와 농축액비는 다량 및 미량원소를 함유하고 부유물질(SS)이 낮아 양액재배시 관배수의 막힘문제 없이 활용이 가능하였다. 여과, 농축액비는 인산, 칼슘, 마그네슘 함량이 낮고 칼륨이 높은 양분불균형를 나타내었다. 2. 여과액비는 원예연 표준양액 대비 총수량 91%, 상품수량 70%를 나타내어 여과액비 단독급액으로 토마토의 유기 수경재배 생산이 가능하였다. 3. 막처리 농축액비 100% 처리구는 토마토의 지상부의 생육이 지연되고 과중이 감소되어 화학양액 대비 40%의 수량을 나타내었다. 4. 퇴비단 여과액비+부산물, 농축액비+부산물 혼합처리구의 토마토 수량은 대조구 대비 각각 87, 76%를 나타내어 여과액비 단독시용구의 수량에 미치지 못하였다. 5. 질소기준으로 여과액비와 농축액비에 양액을 50% : 50% 비율로 혼합하여 균형처방 처리한 경우 표준양액 처리와 대등한 수량을 나타내었다. 결론적으로 토마토 양액재배에서 생육과 수량을 고려할 때 액비와 양액의 50 : 50 혼합 재배시 수량이 유지되어 가축분뇨 유래 유기액비에 의하여 화학양액를 50% 대체할 수 있을 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제20권8호
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• pp.1219-1225
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• 2010

Actinobacillus succinogenes, a representative succinicacid-producing microorganism, is seriously inhibited by ammonium ions, thereby hampering the industrial use of A. succinogenes with ammonium-ion-based materials as the pH controller. Therefore, this study isolated an ammonium-ion-tolerant mutant of A. succinogenes using a continuous-culture technique in which all the environmental factors, besides the stress (ammonium ions), were kept constant. Instead of operating the mutant-generating system as a nutrient-limited chemostat, it was used as a nutrient-unlimited system, allowing the cells to be continuously cultured at the maximum specific growth rate. The mutants were isolated on agar plates containing the acid-base indicator bromothymol blue and a high level of ammonium ions that would normally kill the parent strain by 100%. When cultured in anaerobic bottles with an ammonium ion concentration of 354 mmol/l, the mutant YZ0819 produced 40.21 g/l of succinic acid with a yield of 80.4%, whereas the parent strain NJ113 was unable to grow. When using $NH_4OH$ to buffer the culture pH in a 3.0 l stirredbioreactor, YZ0819 produced 35.15 g/l of succinic acid with a yield of 70.3%, which was 155% higher than that produced by NJ113. In addition, the morphology of YZ0819 changed in the fermentation broth, as the cells were aggregated from the beginning to the end of the fermentation. Therefore, these results indicate that YZ0819 can efficiently produce succinic acid when using $NH_4OH$ as the pH controller, and the formation of aggregates can be useful for transferring the cells from a cultivation medium for various industrial applications.