• Environmental Engineering Research
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• 제20권3호
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• pp.246-253
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• 2015

The effects of carbon-to-nitrogen (C/N) ratio in simulated rice straw hydrolysates using glucose and ammonium chloride on polyhydroxyalkanoates (PHA) accumulation by Cupriavidus necator was investigated. In general, PHA accumulation rate was higher under higher degrees of N-deficient conditions (e.g., C/N ratio of 360:1) than lower degrees of N-deficient conditions (e.g., C/N ratio of 3.6:1 and 36:1). Also, the most PHA accumulation was observed during the first 12 h after the PHA accumulation initiation. This study showed that the similar PHA accumulation could be achieved by using different accumulation periods depending on C/N ratios. N source presence was important for new cell production, supported by approximately ten times greater PHA accumulation under the N-deficient condition ($NH_4Cl$ 0.01 g/L) than the N-free (without $NH_4Cl$) condition after 96 h. C/N ratio of the rice straw hydrolysate was approximately 160:1, based on the glucose content, and this accumulated $0.36{\pm}0.0033g/L$ PHA with PHA content of $21{\pm}3.1%$ after 12 h. Since external C or N source addition for C/N ratio adjustment increases production cost, an appropriate accumulation period may be used for PHA accumulation from organic wastes, based on the PHA accumulation patterns observed at various C/N ratios and C and N concentrations.

• Applied Biological Chemistry
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• 제7권
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• pp.29-33
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• 1966

이 시험(試驗)은 쥐오줌의 energy value와 nitrogen content와의 관계(關係)를 연구(硏究)하기 위하여 행(行)하여졌다. 이 시험(試驗)을 위하여 ad lib.구(區)에 13 마리, 2 meals구(區)에 16 마리, 도합(都合) 29 마리의 쥐가 쓰였다. 오줌의 채집(採集)은 22 일간(日間)의 본시험기간중(本試驗期間中) 8 일(日)동안 행(行)하였다. 1 일(日) 2회(回) 채식(採食)시킨 쥐들이 훨씬 많은 (p<0.05) nitrogen 을 배설(排泄)했고 아울러 더 많은 energy를 배설(排泄)하였다. 쥐오줌의 energy concentration과 nitrogen content 사이에는 직선관계(直線關係)가 있어서 nitrogen 함량(含量)이 증가(增加)하면 energy의 배설량(排泄量)이 증가(增加)된다는 사실(事實)이 밝혀 졌다. urinary nitrogen(X, gm/100 ml)으로 부터 energy value (Y, kcal/100 ml)를 산출(算出)할 수있는 공식(公式)을 유도(誘導)했는데 다음의 식(式)은 일반적(一般的)으로 이 목적(目的)을 위하여 쓰여질 수 있는 것으로 본다. Y=8.924X+0.182 (Y=urinary energy, X=urinary N) 이러한 산출(算出)에 수반(隨伴)도는 표준오차(標準誤差)는 0.788 kcal이다. nitrogen content로부터 energy concentration을 산출(算出)하는데 따르는 오차(誤差)가 이렇게 적기 때문에 또 urinary energy의 함량(含量)이 GE, DE, ME, 섭취량(攝取量)에 비(比)해 적기 때문에 유사(類似)한 Diet를 공급(供給)하는 경우(境遇) 이 식(式)은 쥐오줌의 energy value를 산출(算出)하는데 쓰일 수 있을 것이다. 따라서 오줌의 energy value의 직접측정(直接測定)에 소요(所要)되는 많은 시간(時間)과 노력(努力)이 절약(節約)되는 것이다. 쥐오줌의 energy: nitrogen의 비(比)는 9.4(ad lib.구(區)) 내지(乃至) 8.6(2 meals 구(區))으로서 채식회수(採食回數)는 이 비율(比率)에 하등(何等)의 영향(影響)이 없음이 밝혀졌다.

• 농업과학연구
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• 제12권2호
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• pp.174-182
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• 1985

우리나라 수도재배상(水稻栽培上) 중요(重要)한 과제(課題)의 하나인 질소효율(窒素效率)을 높이면서 다수확(多收穫)을 기(期)할 목적(目的)으로 생육후기(生育後期)의 질소추비(窒素追肥)의 효과(效果)를 구명(究明)코자 실험(實驗)한 바 다음 결과(結果)를 얻었다. 1. 질소(窒素) 증시(增施)에 의해서 엽면적(葉面績)과 순동화율(純同化率)이 향상(向上)되고 많은 영화수(穎花數)가 확보(確保)되었다. 2 질소(窒素)의 생육후기(生育後期) 중점시용(重點施用)은 생식생장기(生殖生長期)와 결실기(結實期)의 생장속도(生長速度)를 높였으며 분얼(分蘖)의 유효화(有效化)및 생산기관(生産器官) 대(對) 비생산기관(非生産器官) 비율(比率)을 크게 만들어 질소효율(窒素效率)을 높이는데 기여(寄與)하였다. 3. 수도(水稻) 다수확재배(多收穫栽培)에서 질소(窒素)의 생육후기중점시용(生育後期重點施用)은 내파성(耐把性) 품종(品種)의 재배(栽培)및 지력배양(地力培養)과 함께 유효(有效)한 방법(方法)이었다.

• 열처리공학회지
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• 제27권1호
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• pp.15-22
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• 2014

This study is to investigate the phase changes and cold workability after isothermal transformation at $780^{\circ}C$ by using the high temperature gas nitrided (HTGN) STS 430 ferritic stainless steel specimens. The phase diagram of STS 430 steel obtained by calculation showed that the phase appeared at $1100^{\circ}C$ showed as ${\alpha}+{\gamma}{\rightarrow}{\gamma}{\rightarrow}{\gamma}+Cr_2N{\rightarrow}{\gamma}+Cr_2N+CrN$ with increasing nitrogen concentration. Also, the transformation of ${\gamma}{\rightarrow}Cr_2N$ during heat treatment isothermally at $780^{\circ}C$, nitrogen pearlite with lamellar type was fully formed at the nitrogen permated surface layer for 10 hrs. However, this transformation was not completed for 1 hr, resulting nitrogen pearlite plus martensite. The cold rolled specimen of isothermally transformed at $780^{\circ}C$ for 10 hrs after high temperature gas nitriding decreased the layer thickness of nitrogen pearlite inducing the deformation of hard $Cr_2N$ phase. the dissolution rate of $Cr_2N$ phase increased rapidly with increasing cold rolling ratio. Specimens with the microstructure of nitrogen pearlite (isothermally transformed at $780^{\circ}C$ for 10 hrs) were possible to cold rolling without crack formation. However, the mixed structures of nitrogen pearlite + martensite (isothermally transformed at $780^{\circ}C$ for 1 hr) were impossible to cold deformation without cracking.

• Asian-Australasian Journal of Animal Sciences
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• 제17권8호
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• pp.1150-1157
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• 2004

This experiment was conducted to investigate effects of phase feeding and sugar beet pulp (SBP) on growth performance, nutrient digestibility, nitrogen excretion, blood urea nitrogen (BUN) concentration and carcass characteristics in finishing pigs. A total of 128 pigs were allotted at 53.9 kg BW to 8 replicates in a 2$\times$2 factorial arrangement in a randomized complete block (RCB) design. The first factor was phase feeding (2 or 3 phase feeding) and SBP (SBP: 0% or 10%) was the second factor. Ten percent SBP supplement groups showed lower average daily feed intake (ADFI) than 0% SBP supplement groups (p<0.05). However, there were no significant difference in average daily gain (ADG) and feed:gain ratio among treatments during overall experimental period. Nutrient digestibility was not affected by phase feeding or SBP supplementation. Urinary nitrogen excretion in 10% SBP supplement group was lower than that in 0% SBP supplement group (p<0.05) and total nitrogen excretion was lower in SBP supplement group than in the group without SBP. Urinary and total nitrogen were numerically decreased in three phase feeding compared to two phase feeding. The BUN concentration in three phase feeding groups was lower than two phase feeding groups at 47 and 63 day (p<0.05). Consequently, results of this experiment demonstrated that three phase feeding was more acceptable than two phase feeding for finishing pigs. And sugar beet pulp could be supplemented in finishing pig diet for decreasing urinary nitrogen excretion without retardation in growth performance of pigs.

• Journal of Microbiology and Biotechnology
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• 제21권10호
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• pp.1073-1080
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• 2011

In order to investigate and generalize the effects of carbon and nitrogen sources on the growth of and lipid production in Chlorella sp. 227, several nutritional combinations consisting of different carbon and nitrogen sources and concentrations were given to the media for cultivation of Chlorella sp. 227, respectively. The growth rate and lipid content were affected largely by concentration rather than by sources. The maximum specific growth was negatively affected by low concentrations of carbon and nitrogen. There is a maximum allowable inorganic carbon concentration (less than 500~1,000 mM bicarbonate) in autotrophic culture, but the maximum lipid content per gram dry cell weight (g DCW) was little affected by the concentration of inorganic carbon within the concentration. The lipid content per g DCW was increased when the microalga was cultured with the addition of glucose and bicarbonate (mixotrophic) at a fixed nitrogen concentration and with the lowest nitrogen concentration (0.2 mM), relatively. Considering that lipid contents per g DCW increased in those conditions, it suggests that a high ratio of carbon to nitrogen in culture media promotes lipid accumulation in the cells. Interestingly, a significant increase of the oleic acid amount to total fatty acids was observed in those conditions. These results showed the possibility to induce lipid production of high quality and content per g DCW by modifying the cultivation conditions.

• KSBB Journal
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• 제11권4호
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• pp.497-503
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• 1996

본 연구에서는 질소원의 종류와 농도 그리고 pH가 플루란 생산에 미치는 영향을 고찰하였다. A Aureobasidium pullulans에 의한 플루란 생산시 가장 좋은 질소원으로는 수율 62%를 얻은 peptone 이었고, 최적 질소원 농도는 유기질소원의 경우 탄 소원/질소의 비가 50j0.15N이었고 그 이상에서는 저해가 일어났다. 훈합질소원 I, II, III을 사용하 였을 때 각각 29.1, 27.4, 26.5g/L의 플루란 생산량 을 보였다. 그러므로, 혼합 질소원을 잘 이용하면 플 루란을 효과적으로 생산할 수 있었다. pH를 조절하 지 않을 때가 pH를 일정하게 할 때보다는 플루란 수율이 높았다. 또, 유가식배양시 탄소원과 질소원을 함께 공급하였을 때가 질소원만을 공급하였을 때 더 큰 플루란 수율을 보였다.

• 한국토양비료학회지
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• 제4권2호
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• pp.161-166
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• 1971

1. 추락답(秋落畓)에 대(對)한 규산(珪酸), 질소(窒素) 및 가리(加里)의 증시효과는 현저하나 질소(窒素)는 수회(數回)로 나누어 분시(分施)하여야 한다. 2. 규산(珪酸)은 질소증시(窒素增施)의 효율을 높인다. 3. 질소(窒素)를 증시(增施)하면 주당수수(株當穗數)는 증가(增加)하나 등숙률(登熟率)이 현저히 감소(減少)된다. 질소증시(窒素增施)로 인(因)하여 감소된 등숙률(登熟率)은 가리증시(加里增施)로 높일 수 있다. 4. 규산시용(珪酸施用)은 추락도(秋落稻)의 등숙률(登熟率)과 수당립수(穗當粒數)를 증가(增加)시켰다. 5. 질소증시(窒素增施)는 식물체(植物體)의 질소함량(窒素含量)을 증가(增加)시키나 규산(珪酸) 및 가리(加里)의 함량(含量)은 감소(減少)되여 규산(珪酸)/질소(窒素) 및 가리(加里)/질소비(窒素比)가 낮아진다. 6. 추락답(秋落畓)에 질소(窒素)를 증시(增施)할 때에는 규산(珪酸) 및 가리(加里)도 함께 증시(增施)하여야 한다.

• 한국토양비료학회지
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• 제6권3호
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• pp.173-177
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• 1973

장려품종이며 온대형질(溫帶形質)인 진흥(振興)과 열대형질(熱帶形質)인 다수성신품종(多收性新品種) IR667을 사용(使用)하여 포장조건(圃場條件)에서 질소(窒素) 수준(水準)에 따른 생산반응을 비교(比較) 검토(檢討)하여 본 결과(結果) 다음과 같다. 1. IR667은 진흥(振興)에 비(比)하여 질소고수준(窒素高水準)에서 엽면적(葉面積) 및 수량(收量)이 높고, 2. 질소증시(窒素增施)에 따른 수수(穗數), 입수(粒數), 입종(粒重), 등숙율(登熟率)의 증가(增加)가 더 크며, 3. 단위시비질소당(單位施肥窒素當) 곡실(穀實) 및 엽면적(葉面積) 생산효율이 높으며, 4. 단위엽면적당(單位葉面積當) 곡실생산력이 높았으며, 5. IR667은 수수(穗數) 및 입수형(粒數型)인데 비하여 진흥(振興)은 입종형(粒重型)이었다. 6. 이상(以上)의 제특성(諸特性)은 IR667이 진흥(振興)에 비하여 포장(圃場)에서 강(强)한 생산성내비성임을 보여주었다.

• 한국농공학회논문집
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• 제63권4호
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• pp.13-21
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• 2021

The feasibility of HWS for agricultural use was analyzed through a crop cultivation test to utilize the hydroponic waste solution (HWS) generated from the nutriculture greenhouse. The fertilizing effect of HWS was assessed on the basis of the inorganic nitrogen (N) mostly existed in HWSs, and nitrogen (urea) fertilizer. Lettuce was selected as the target crop influenced by the soil treatment and also for the crop cultivation test. Thus, the change in growth characteristics of lettuce and that in chemical characteristics of the soil were investigated. In terms of the growth of lettuce, the C control group with 70% nitrogen (urea) fertilizer and 30% HWS and the D control group with 50% nitrogen (urea) fertilizer and 50% HWS were more effective than the practice control group (B) with 100% nitrogen (urea) fertilizer. The results of this study confirmed the combined applicability of the chemical fertilizer and HWS for crop cultivation. Because NO₃-N present in HWS has a high possibility of leaching into the soil, its applicability as a fertilizer has been considered to be relatively low in Korea. However, if an appropriate mixing ratio of urea fertilizer and HWS could be applied, the problems associated with leaching of nitrate nitrogen could be reduced with beneficial effects on crop cultivation. Thus, future studies are required on the treatment effect of HWS with repeated cultivation, impact assessment on the surrounding environment, and appropriate fertilization methods using nitrogen (urea) fertilizer and HWS. These studies would facilitate the sustainable recycling of HWS.