• Asian-Australasian Journal of Animal Sciences
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• 제19권1호
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• pp.48-54
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• 2006

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid) has been used as feed additives in poultry industries to improve production and control coccidiosis. The effect of high dietary levels of Roxarsone (ROX) on the performance and function of internal organs and the kinetics of recovery as well as its after-effects were examined in laying hens. The inclusion rates of ROX were 0, 100, 200, 300, and 400 mg per kg feed. Inclusion up to 200 mg did not show any adverse effects (p>0.05), whereas in the 300 and 400 mg groups, significant effects, particularly in the latter, were observed for three weeks after ROX addition (p<0.05). Recovery of the physical appearance occurred soon after ROX addition was withdrawn. Recovery of performance and internal organs, however, appeared to be dependent on the amount of residual ROX in the body; as the amount of ROX decreased, the toxic effect of ROX also decreased. In the third week after the withdrawal of ROX, complete recovery was observed in the lower dosage groups (100 or 200 mg groups) (p>0.05), whereas in the higher dosage groups (300 or 400 mg groups), recovery took at least five weeks; when complete recovery was observed in egg production and in liver weight (p>0.05). On the other hand, ROX might have damaged the liver and other tissues. The recovery of liver weight was probably due to accumulation of fatty particles rather than repair. It appeared, therefore, there were little after-effects of ROX on the hen's physical appearance, but some internal organs were probably damaged.

• 한국항공우주학회지
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• 제50권4호
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• pp.223-231
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• 2022

금속 적층제조 공정 중 발생할 수 있는 잔류응력은 3D 프린팅을 통한 정밀한 금속 부품 제작을 위해 적절히 통제되어야 하는 중요한 요소이다. 따라서 본 연구에서는 이러한 잔류응력에 영향을 끼치는 요인에 대하여 실험적인 방법을 이용하여 고찰하였다. 실험을 위해 적층제조 공정을 통해 시편을 제작하고 이를 절단하여 변형량 측정을 수행하였으며, 측정된 데이터를 curve fitting 등의 방법을 이용하여 적절히 보정함으로써 공정 파라미터 및 금속 분말 재사용 여부가 금속 적층제조 공정에서 발생한 잔류응력으로 인한 변형에 끼치는 영향을 정량적으로 분석할 수 있는 자료를 확보하였다. 이 결과로부터 금속 적층제조 공정에서 잔류응력으로 인한 변형의 크기에 가장 큰 영향을 끼치는 요소는 금속 분말 재사용 여부임을 확인하였다. 또한 레이저의 패턴, 적층 회전 각도와 같은 공정 파라미터도 변형 크기에 영향을 줄 수 있는 것을 확인하였다.

• 대한환경공학회지
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• 제29권3호
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• pp.277-282
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• 2007

본 연구에서는 보다 정확하고 실용적인 배출수처리시설 용량산정 및 설계 도구를 개발하고자, Excel 프로그램을 이용하여 계산과정을 전산화한 배출수처리시설 설계용 프로그램을 개발하였다. 배출수처리시설 설계용 프로그램은 슬러지 발생량 산정, 물질수지의 계산, 그리고 단위공정의 제원결정을 순서대로 수행할 수 있도록 구성되어 있다. 특히 본 프로그램에는 여과지 역세척수를 회수하기 위한 시스템이 포함되어 있다. 배출수처리시설 설계용 프로그램을 대청호 원수를 취수하는 청주정수장을 대상으로 실행한 결과, 반복계산으로 인한 계산착오 문제를 해결할 수 있었으며, 계산과 설계에 소요되는 시간을 크게 줄일 수 있었다. 본 프로그램은 기존정수장 배출수처리시설의 성능개선 뿐만 아니라 새로운 정수장에도 적용될 것으로 기대된다.

• 한국물환경학회지
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• 제25권6호
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• pp.979-983
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• 2009

The mean pH of wastewater discharged from the plating process is 2, so a less amount of alkali is required to raise pH 2 to 5. In addition, if sodium sulfite is used to raise pH 5 to 9 in the secondary treatment, caustic soda or slaked lime is not necessary or only a small amount is necessary because sodium sulfite is alkali. Thus, it is considered desirable to use only $FeSO_4{\cdot}7H_2O$ in the primary treatment. At that time, the free cyanide removal rate was highest as around 99.3%, and among heavy metals, Ni showed the highest removal rate as around 92%, but zinc and chrome showed a low removal rate. In addition, the optimal amount of $FeSO_4{\cdot}7H_2O$ was 0.3g/L, at which the cyanide removal rate was highest. Besides, the free cyanide removal rate was highest when pH value was 5. Of cyanide removed in the primary treatment, the largest part was removed through the precipitation of ferric ferrocyanide: $[Fe_4(Fe(CN)_6]_3$, and the rest was precipitated and removed through the production of $Cu_2[Fe(CN)_6]$, $Ni_2[Fe(CN)_6]$, CuCN, etc. Furthermore, it appeared more effective in removing residual cyanide in wastewater to mix $Na_2SO_3$ and $Na_2S_2O_5$ at an optimal ratio and put the mixture than to put them separately, and the optimal weight ratio of $Na_2SO_3$ to $Na_2S_2O_5$ was 1:2, at which the oxidative decomposition of residual cyanide was the most active. However, further research is required on the simultaneous removal of heavy metals such as chrome and zinc.

• Asian-Australasian Journal of Animal Sciences
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• 제30권8호
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• pp.1168-1174
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• 2017

Objective: The aim of the study was to evaluate the effects of different nitrate levels (150, 300, 450, and 600 ppm $KNO_3$) on the volatile compounds and some other properties of pastırma. Methods: Pastırma samples were produced under the controlled condition and analyses of volatile compounds, and thiobarbituric acid reactive substances (TBARS) as an indicator of lipid oxidation, non-protein nitrogenous matter content as an indicator of proteolysis, color and residual nitrite were carried out on the final product. The profile of volatile compounds of pastırma samples was analyzed by gas chromatography/mass spectrometry using a solid phase microextraction. Results: Nitrate level had a significant effect on pH value (p<0.05) and a very significant effect on TBARS value (p<0.01). No significant differences were determined in terms of $a_w$ value, non-protein nitrogenous substance content, color and residual nitrite between pastırma groups produced by using different nitrate levels. Nitrate level had a significant (p<0.05) or a very significant (p<0.01) effect on some volatile compounds. It was determined that the amounts and counts of volatile compounds were lower in the 450 and especially 600 ppm nitrate levels than 150 and 300 ppm nitrate levels (p<0.05). While the use of 600 ppm nitrate did not cause an increase in residual nitrite levels, the use of 150 ppm nitrate did not negatively affect the color of pastırma. However, the levels of volatile compounds decreased with an increasing level of nitrate. Conclusion: The use of 600 ppm nitrate is not a risk in terms of residual nitrite in pastırma produced under controlled condition, however, this level is not suitable due to decrease in the amount of volatile compounds.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.8-13
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• 1998

Animal cells in culture typically convert most of the glucose they consume into lactate. The accumulation of lactate, however, is commonly cited as one of the factors that inhibit cell growth and limit the maximum cell concentration that can be achieved in culture. The specific production of lactate and the amount of glucose converted to lactate can be reduced when cells are grown in a fed-batch culture in which the residual glucose concentration is maintained at low levels. Such a fed-batch culture was used to grow and adapt hybridoma cells into a low-lactate-producing state before changing into continuous culture. The cells reached and maintained a high viable cell concentration at steady state. In a similar manner, cells that were initially grown in batch culture and a glucose-rich environment reached a steady state with a cell concentration that is much lower. The feed composition and dilution rates for both cultures were similar, suggesting steady state multiplicity. From a processing perspective the desired steady state among those is the one with the least metabolite production. At such seady state nutrient concentration in the feed can be further increased to increase cell and product concentrations without causing the metabolite inhibitory effect typically seen in a cell culture. Controlling cell metabolism in a continuous culture to reduce or eliminate waste metabolite production may significantly improve the productivity of mammalian cell culture processes.

• 한국연초학회지
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• 제6권2호
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• pp.155-168
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• 1984

Field test were conducted to select the best method for soil phosphorus test and to obtain the critical levels of each method for P fertilizer recommendations based on tobacco production. Truog method was recognized to be the mort suitable one for soil P test. N. Carolina, Bray No.1 and Olsen methods were followed in order. Bray No. 2 and Lancaster methods showed the least satisfaction. The critical levels of available P by lancaster, Bray No. 1, N. Carolina,01sen, and Truog methods were 55ppm, 32ppm, 21ppm, 19ppm, and 22ppm, respectively. Below the critical level a large yield response can be expected with 10kg $P_2O_5$/10a, above critical level little or no response is expected. In soils the more the initial available p, the more available P was carried over, while the more the total amount of silt and clay, the less the residual P was found. The increase in residual P by 10kg of $P_2O_5$ was greater than that of 5kg/10a. The chemical composition and the price of the cured leaf were not affected by the $P_2O_5$ application, indicating that the increase in the rate of $P_2O_5$ application would not exert on the quality of tobacco.

• Journal of the Korean Wood Science and Technology
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• 제20권4호
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• pp.65-72
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• 1992

Steam defiberated pulp and steam exploded wood(birch chip) were extracted with solvents (hot-water, 1% NaOH, MeOH, hot water, 1% NaOH). The properties of residual fiber were examined for the utilization as ruminants feed. The digestibility is 38% in steam defiberated pulp(10kg /$cm^2$-15min) and 62-77% in exploded wood(17-18kg/$cm^2$-2~10min), respectively. The more steam pressure and time increase, the more the digestibility increase. The sugars obtained from extractives is amount from 7% to 13% in asplund pulp and from 7% to 10% in exploded pulp. The sugars was mainly composed of 70-80% xylose. The digestibility of residual fiber which is extracted with solvents is low than these of original fibers. Considering the yield and digestibility as ruminant feed, exploded pulp under 17kg /$cm^2$ for 10min has the best efficiency. The exploded wood gives 75.3% on yield(O. D. chip) and 48% on the digestibility.

• 한국축산식품학회지
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• 제23권4호
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• pp.299-308
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• 2003

돈육소시지에 녹차의 다양한 생리 기능성을 부여하고 소시지의 저장성과 품질을 유지하면서 아질산염의 사용을 감소시킬 수 있는지 알아보기 위하여 녹차 분말을 첨가하여 돈육 소시지를 제조하여 저장 중 품질 특성을 살펴보았다. 아질산염(50, 100, 150 ppm)과 녹차(0, 0.5, 1.0%)를 첨가한 총 9개 시험군의 소시지를 제조하여 1$0^{\circ}C$와 2$0^{\circ}C$에 나누어 저장하면서 아질산염, TBARS와 VBN 등 저장성을 검사하였다. 수분, 조단백, 조지방, 조회분 등 일반성분은 녹차와 아질산염 첨가에 의해 영향을 받지 않았다. 색깔은 녹차 첨가량이 많을수록 밝기와 적색도가 감소한 반면 황색도가 증가하였다. 소시지의 아질산 잔류량을 분석한 결과 아질산염 첨가량이 동일한 경우 녹차 첨가량이 많을수록 아질산 잔류량이 적어 녹차 첨가가 아질산 잔유량 감소에 도움이 되는 것으로 나타났다. 녹차의 첨가는 소시지 제조 초기 및 저장 중 TBARS 값을 유의적으로 감소시켰으며, 이러한 녹차의 TBARS 감소 효과는 낮은 농도의 아질산염을 사용한 경우에 더욱 감소효과가 컸다. 저장 중 휘발성 염기태질소(VBN) 함량도 녹차와 아질산염을 첨가한 군에서 낮은 값을 보였다. 이상의 결과로 보아 돈육소시지에 녹차를 첨가함으로써 아질산 잔류량을 감소시킬 수 있을 뿐 아니라 저장성을 크게 훼손하지 않고 아질산염의 사용을 줄일 수 있다고 사료된다.

• 대한영양사협회학술지
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• 제25권1호
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• pp.44-58
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• 2019

Predicting the number of meals in a foodservice organization is an important decision-making process that is essential for successful food production, such as reducing the amount of residue, preventing menu quality deterioration, and preventing rising costs. Compared to other demand forecasts, the menu of dietary personnel includes diverse menus, and various dietary supplements include a range of side dishes. In addition to the menus, diverse subjects for prediction are very difficult problems. Therefore, the purpose of this study was to establish a method for predicting the number of meals including predictive modeling and considering various factors in addition to menus which are actually used in the field. For this purpose, 63 variables in eight categories such as the daily available number of people for the meals, the number of people in the time series, daily menu details, weekdays or seasons, days before or after holidays, weather and temperature, holidays or year-end, and events were identified as decision variables. An ensemble model using six prediction models was then constructed to predict the number of meals. As a result, the prediction error rate was reduced from 10%~11% to approximately 6~7%, which was expected to reduce the residual amount by approximately 40%.