• 미생물학회지
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• 제46권2호
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• pp.183-191
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• 2010

본 연구에서는 성장기질로써 다양한 방향족 화합물을 첨가하여 TCE 분해 균주를 분리하고 고효율 TCE 분해 균주에 의한 고농도의 TCE 분해 특징에 대해 연구하였다. TCE에 오염된 토양 및 폐수로부터 시료를 채취하였고 성장기질로써 벤젠(Benzene), 페놀(Phenol), 에틸벤젠(Ethylbenzene), 아닐린(Aniline), 큐멘(Cumene), 톨루엔(Toluene) 등을 사용하여 TCE에 내성을 가지는 179 균주를 순수 분리하였다. 순수 분리된 균주들을 TCE 농도 30 mg/L, 성장기질 농도 0.2 g/L, $30^{\circ}C$, pH 7, 균 농도 1.0 g/L (w/v)의 호기적 조건으로 21일 동안 분해효율을 측정한 결과, 아닐린을 성장기질로 이용한 EK2 균주가 74.4%의 가장 높은 효율을 보여주었다. EK2 균주는 형태학적 특징, 생화학적 특징 및 분자적 특징을 분석한 결과 Delftia acidovorans로 동정되었다. D. acidovorans EK2의 TCE 분해는 TCE 농도 10에서 200 mg/L까지 성장 및 분해할 수 있었으나 250 mg/L 이상의 농도에서는 성장과 분해가 보이지 않았다. 저농도(1.0 mg/L) 분해 실험을 위하여 D. acidovorans EK2를 각 0.01 g/L, 0.03 g/L, 0.05 g/L로 적용한 결과, 모든 조건에서 12일 동안 99.9%의 분해효율을 보였다. 고농도(200 mg/L)를 분해하기 위한 최적 배양조건은 균 농도 1.0 g/L, 아닐린 농도 0.5 g/L, pH 7, 온도 $30^{\circ}C$로 확인되었으며, 21일 동안 호기적으로 배양 시 71.0%의 가장 높은 TCE 분해효율을 보여주었고, 분해속도는 94.7 nmol/h이었다. 결과적으로 본 연구에서 개발된 D. acidovorans EK2를 이용하여 고농도의 TCE로 오염된 토양 및 지하수의 생물학적 처리에 효율적으로 이용될 수 있을 것으로 사료된다.

• 대한전기학회논문지
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• 제45권1호
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• pp.1-8
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• 1996

Recently, much attention has been paid to problems which is concerned with voltage instability phenomena and much works on these phenomena have been made. In this paper, by substituting d $P_{k}$ d $e_{k}$ ( $v^{\rarw}$= e +j f) for $P_{k}$ in conventional load flow, direct method for finging the limit of voltage stability is proposed. Here, by using the fact that taylor se- ries expansion in .DELTA. $P_{k}$ and .DELTA. $Q_{k}$ is terminated at the second-order terms, constraint equation (d $P_{k}$ d $e_{k}$ =0) and power flow equations are formulated with new variables .DSLTA. e and .DELTA.f, so partial differentiations for constraint equation are precisely calculated. The fact that iteratively calculated equations are reformulated with new variables .DELTA.e and .DELTA.f means that limit of voltage stability can be traced precisely through recalculation of jacobian matrix at e+.DELTA.e and f+.DELTA.f state. Then, during iterative process divergence may be avoid. Also, as elements of Hessian mat rix are constant, its computations are required only once during iterative process. Results of application of the proposed method to sample systems are presented. (author). 13 refs., 11 figs., 4 tab.

• Asian-Australasian Journal of Animal Sciences
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• 제14권2호
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• pp.224-230
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• 2001

This study was conducted to evaluate the extruding effects of corn and wheat on growth performance and fecal digestibility of amino acids in early-weaned pigs. Ground corn and wheat by a hammer mill (3 mm screen in diameter) were extruded at $130{\pm}2^{\circ}C$ with a moist-type extruder ($Matador^{(R)}$). Treatments were: 1) 3 mm ground corn, 2) extruded corn, 3) 3 mm ground wheat, and 4) extruded wheat. A total of 160 pigs (14 d of age and $4.3{\pm}0.74kg$ BW) were allotted with the dietary treatments for a 21-d feeding trial. All diets were mash and contained 30% corn or wheat products. For a digestibility trial, 16 pigs (14-d old and $4.2{\pm}0.32kg$ BW) were employed in individual metabolic crates. There were no differences (p>0.15) in growth performance between corn-fed and wheat-fed groups. Feeding pigs diets containing extruded corn or wheat did not affect ADG (p>0.15) and ADFI (p>0.15), but it improved feed/gain (p<0.01). Also, feeding pigs diets containing extruded corn or wheat had lower true fecal digestibilities of arginine, histidine, isoleucine, lysine and valine (p<.007) in the pigs. In conclusion, our results suggest that extruding corn and wheat had no benefit on the growth of early-weaned pigs.

• Asian-Australasian Journal of Animal Sciences
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• 제14권1호
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• pp.61-69
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• 2001

A total of 120 pigs were used to investigate the effects of yucca extracts on the growth performance, nutrient digestibility and excretion of growing pigs fed different levels of dietary protein. Pigs were allotted into $2{\times}3$ factorial design by the supplementation with yucca extract (YE, 0 and 120 mg/kg) and 3 levels of dietary protein (16, 18, 20%). During the whole experimental period (18 to 52 kg body weight), there were no significant differences in ADG, ADFI or F/G by YE addition or different protein levels among treatments (p>0.05). Overall, although addition of YE to the diet and elevation of protein level showed better ADG, there were no significant differences in growth performance among treatments. Pigs fed diets with YE showed significantly (p<0.05) higher dry matter (DM), crude ash (CA) and crude protein (CP) digestibility than did the others during the growing period. Concerning the levels of dietary protein, only the CP digestibility was significantly higher in pigs fed high protein diet. Pig fed the low protein diet without YE showed a significantly low CP digestibility (p<0.05). No significant differences were found in crude fat (CF), calcium (Ca) and phosphorus (P) digestibilities regardless of YE supplementation or dietary protein levels. Pigs fed YE supplemented diets showed significantly (p<0.05) higher amino acid digestibility. Also, high CP level diets showed a higher amino acid digestibility than low CP diets (p<0.05). DM and N excretion did not show any significant differences among treatments, there was a slightly lower excretion with increase in dietary protein level. Supplementation with YE significantly decreased the DM and N excretion. Interaction (YE$\times$protein) was found in P excretion. Pigs fed a medium protein diet without YE showed the lowest P excretion during the growing period. The NH3-N content in the feces tended to be increased by the increased dietary protein levels and with YE supplementation. During the whole experimental period, the cost for YE supplementation was similar to value of the improvements of performance obtained. The cost of feeding high level protein was significantly higher than that of medium level protein by 10% and low level protein by 9% (p<0.05). It could be concluded that the effects of dietary protein level and yucca extract on growth performance, nutrient digestibility and excretion might play a role to some extent in growing pigs from the aspect of pollution control.

• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7689-7694
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• 2015

Background: Bone tumors are neoplasias with a high overall mortality; one of the main factors that reduce survival is their high capacity to develop metastases. It has been reported that finding lung metastases at diagnosis of osteosarcoma (OS), chondrosarcoma (CS) and giant cell tumor of bone (GCTb) is quite common. In this study, we inquire the relationship of metastases caused by these tumors with different clinical and pathological aspects, in order to guide medical personnel in the diagnosis and opportune treatment of metastases or micro metastases. Materials and Methods: We collected data of 384 patients with clinical, radiological and histopathological diagnosis of OS, GCTb and CS that attended the National Rehabilitation Institute (INR) during 2006 to 2014. Chi-square and Fisher's exact tests were performed for data analysis. Results: In the three tumor types, the presence of metastases at diagnosis was variable (p=0.0001). Frequency of metastases was 36.7%, 31.7% and 13.2% for OS, CS and GCTb respectively. The average age had no significant difference (p>0.05) in relation to metastases, even so, patients with OS and GCTb and metastases, were older while patients with CS and metastases were younger, in comparison to patients without metastases. Males had a higher frequency of metastases (68.2%, p = 0.09) in contrast to CS and GCTb, in which the metastases was more frequent in women with 51.9% (p = 0.44) and 57.9% (p = 0.56) respectively. Broadly, metastasis was associated with primary tumors located in the femur (44.4%), followed by the tibia (15.6%); metastases was more frequent when primary tumor of GCTb and OS were in the same bones, but were located in the hip (26.3%) for CS. Conclusions: The frequency of metastases in OS, GCTb and CS is high in our population and is determined by different clinicopathological variables related to the kind of tumor. Further studies are needed in order to evaluate metastases subsequent to diagnosis and associations with survival and clinicopathological factors, as well as to determine the sensitivity and specificity of current methods of detection.