• 제목/요약/키워드: minimal condition

검색결과 364건 처리시간 0.022초

도토리 화분의 발아 조건에 따른 식품유해균 억제효과 (Inhibition Effect of the Harmful Food-Born Microorganisms on Germination Condition of Acorn Pollen)

  • 최준혁;임가영;장세영;정용진
    • 한국식품저장유통학회지
    • /
    • 제14권1호
    • /
    • pp.87-93
    • /
    • 2007
  • 화분의 발아조건에 따른 식품유해균에 대한 항균성을 비교 조사하였다. 그 결과 10%(w/v)설탕용액에 화분 8%(w/v)를 첨가하여 $30^{\circ}C$에서 4일간 발아시켰을 때 식품유해균에 대한 항균활성이 가장 높게 나타났다. 화분발아액의 최소저해농도를 그람양성세균은 $40\;{\mu}L/mL$, 그람음성세균은 $30\;{\mu}L/mL$에서 균생육이 억제되는 것으로 나타났다. 화분발아액의 유기산을 조사한 결과 acetic acid와 lactic acid의 함량이 높은 것으로 나타났다. 화분발아액의 열과 pH 안정성을 조사한 결과 열에 대해서는 안정하지만 pH 안정성은 낮은 것으로 나타났다. 이상의 결과로 도토리 화분발아액은 항균활성이 있는 것으로 나타나 천연항균제로 활용이 기대되었다.

프로그레시브 전단 공정에서 박판 핀 비틀림 최소화를 위한 스프링 배치 최적화 (Optimization of Spring Layout for Minimizing Twist of Sheet Metal Pins in Progressive Shearing)

  • 송호권;심정길;금영탁
    • 소성∙가공
    • /
    • 제23권8호
    • /
    • pp.501-506
    • /
    • 2014
  • Progressive shearing with blanking dies is commonly employed to produce large quantities of tiny sheet metal electronic parts. Sheet metal pins, which are narrow and long, that are sheared with a progressive die set are often twisted. The twist in the sheet metal pins, which usually occurs in the final shearing operation, generally decreases with increasing blank holding force. The blank holding forces in all shearing operations are not the same because of different shearing positions and areas. In the current study, the optimal layout of the springs in a progressive die set to minimize the twist of the sheet metal pin is proposed. In order to find the holding force acting on the tiny narrow blanks produced with the proposed springs during the shearing process, the equivalent area method is used in the structural analysis. The shearing of the sheet-metal pin was simulated to compute the twist angle associated with the blank holding force. The constraint condition satisfying the pre-set blank holding force from the previous shearing operations was imposed. A design of experiments (DOE) was numerically implemented by analyzing the progressive die structure and by simulating the shearing process. From the meta-model created from the experimental results and by using a quadratic response surface method (PQRSM), the optimal layout of the springs was determined. The twist of sheet metal pin associated with the optimal layout of the springs found in the current study was compared with that of an existing progressive die to obtain a minimal amount of twist.

메카노 규제 이론에 기초한 복합재료 IM-rod가 적용된 골절부의 세포분화과정의 유한요소해석 (Finite element analysis of tissue differentiation process in fractured bones applied by a composite IM-rod based on a mechano-regulation theory)

  • 손대성;;장승환
    • Composites Research
    • /
    • 제25권5호
    • /
    • pp.136-140
    • /
    • 2012
  • 본 논문에서는 복합재료 IM rod가 적용된 골절부의 세포 분화과정을 모사하기 위해 유한요소해석을 실시하였다. 세포의 골화과정을 해석하기 위해 편향 변형률을 이용한 메카노 규제 이론을 사용하였으며, 반복 계산을 위해 Python 코드를 이용하여 서브루틴을 구현하였다. 치료에 가장 적절한 복합재료 IM rod의 강성을 찾기 위해 직물 탄소섬유/에폭시 복합재료 (WSN3k)의 적층각도를 바꾸어 해석을 실시하였다. 골절부에 가해지는 기계적 자극에 따른 치료효율을 비교하기 위해 두 가지 초기 하중 조건을 적용하였다. 그 결과 치료효율은 강성의 차이보다 하중에 의해 큰 영향을 받았으며, 초기 하중이 몸무게의 10%이고, 적층순서가 $[{\pm}45]_{nT}$일 때 치료효율이 가장 높았다.

Ecosystem Health Assessments of Changwon Stream as a Preliminary Diagnosis for Aquatic Ecosystem Restoration

  • Han, Jung-Ho;Bae, Dae-Yeul;An, Kwang-Guk
    • 생태와환경
    • /
    • 제40권4호
    • /
    • pp.527-536
    • /
    • 2007
  • In this study, we applied 10-metric health assessment model, based on the Index of Biological Integrity (IBI) during 2006 in the Changwon Stream, which is located in the Changwon city, Gyeongnam province, S. Korea, and then compared with water quality data. The Index of Biological Integrity (IBI) in the Changwon Stream varied from 18 to 38 in the watershed depending on the sampling location and averaged 30.3 (n=6) during the study. Analysis of tolerance guilds showed that the proportion of sensitive species was 13%, but tolerant and intermediate species were 34% and 53%, respectively. Qualitative Habitat Evaluation Index (QHEI) averaged 43.3 (range: 65-104, n=6) indicating non-supporting condition, based on the criteria of U.S. EPA (1993). Values of QHEI showed a typical longitudinal decreases from the headwater reach to the downstream location, except for Site 1 with a low QHEI value by artificial habitat by concrete construction. Minimum QHEI was found in Site 4 where fish diversity was minimal. Conductivity increased continuously along the gradients and especially showed abrupt increases in the downstream sites along with turbidity. Stream ecosystem health of IBI matched to the values of QHEI except for S6. Low IBI values in the sites 4 and 5 was considered to be a result of combined effects of chemical pollutions and habitat degradations. Our results support the hypotheses of Plafkin et ai. (1989) that physical habitat quality directly influences the trophic structure and species richness, and is closely associated with IBI values.

Using Chemical and Biological Approaches to Predict Energy Values of Selected Forages Affected by Variety and Maturity Stage: Comparison of Three Approaches

  • Yu, P.;Christensen, D.A.;McKinnon, J.J.;Soita, H.W.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제17권2호
    • /
    • pp.228-236
    • /
    • 2004
  • Two varieties of alfalfa (Medicago sativa L cv. Pioneer and Beaver) and timothy (Phleum pratense L cv. Climax and Joliette), grown at different locations in Saskatchewan (Canada), were cut at three stages [1=one week before commercial cut (early bud for alfalfa; joint for timothy); 2=at commercial cut (late bud for alfalfa; pre-bloom head for timothy); 3=one week after commercial cut (early bloom for alfalfa; full head for timothy)]. The energy values of forages were determined using three approaches, including chemical (NRC 2001 formula) and biological approaches (standard in vitro and in situ assay). The objectives of this study were to determine the effects of forage variety and stage of maturity on energy values under the climate conditions of western Canada, and to investigate relationship between chemical (NRC 2001 formula) approach and biological approaches (in vitro and in situ assay) on prediction of energy values. The results showed that, in general, forage species (alfalfa vs. timothy) and cutting stage had profound impacts, but the varieties within each species (Pioneer vs. Beaver in alfalfa; Climax vs. Joliette in timothy) had minimal effects on energy values. As forage maturity increased, the energy contents behaved in a quadratic fashion, increasing at stage 2 and then significantly decreasing at stage 3. However, the prediction methods-chemical approach (NRC 2001 formula) and biological approaches (in vitro and in situ assay) had great influences on energy values. The highest predicted energy values were found by using the in situ approach, the lowest prediction value by using the NRC 2001 formula, and the intermediate values by the in vitro approach. The in situ results may be most accurate because it is closest to simulate animal condition. The energy values measured by biological approaches are not predictable by the chemical approach in this study, indicating that a refinement is needed in accurately predicting energy values.

완료적 갑상선 전 절제술의 임상분석 (Clinical Analysis of Completion Thyroidectomy)

  • 이상수;김중규
    • 대한두경부종양학회지
    • /
    • 제14권1호
    • /
    • pp.94-98
    • /
    • 1998
  • Background: Completion thyroidectomy can most accurately be described as reexploration of the neck to remove the contralateral thyroid lobe. This procedure has commonly been performed when the histopatholoic condition of the ipsilateral thyroid lobe reveals papillary or follicular carcinoma of the thyroid. Because of a definitely increased risk of complications with completion thyroidectomy, avoiding its routine use is important. But this operation is safe procedure with minimal morbidity by coinsidering interval, surgical approach, surgeon's experience. The purpose of this review is to define the indication, and the safety of completion thyroidectomy. Materials & Methods: Recent 2 years(1995. 1 to 1996. 12), we have performed 161 thyroid operations. Fourteen of these patients were treated by completion thyroidectomy. The patients ranged in age from 21 to 66 years. We have routinely used ultrasound guided needle biopsy and intraoperative frozen section. Result: The completion thyroidectomized specimen contained papillary carcinoma in 12 (86%), follicular carcinoma in 1(7%) and follicular adenoma(no residual tumor) in 1(7%). The complication of completion thyroicetomy was absent, although case number was a few. The indication of completion thyroidectomy in our study was defined recurrence in 9 and staging in 5. The site of recurrence consists of residual thyroid in 7 and residual thyroid added cervical lymph node in 2. The staging consists of incomplete thyroidectomy 3, questionable frozen biopsy 1, and huge follicular carcinoma. Conclusion: The incidence of completion thyroidectomy appear to be increasing by application of ultrasonogram in follow-up of thyroidectomized patients, especially, for the improving of well differentiated thyroid carcinoma. Experience suggests that the morbidity of completion thyroidectomy is low, so we recommend completion thyroidectomy as an efficient and safe method of surgical treatment.

  • PDF

소의 혈청 Ornithine Carbamyltransferase 활성도 측정에 필요한 적합한 조건에 관한 연구 (A Study on Optimal Conditions for Serum Ornithine Carbamyltransferabe Determination in Cattle)

  • 이창우
    • 한국임상수의학회지
    • /
    • 제2권1호
    • /
    • pp.105-114
    • /
    • 1985
  • The optimal conditions for the evaluation of serum ornithine carbamyltransferase activity, based on the do-termination of citrulline formed during the enzymatic reaction, were investigated and the serum ornithine carbamyltransferase activity of cattle were surveyed. Barbital-acetate buffer(70m moles/L, pH 7.0 at $37^{\circ}C$) were usea for the entire experiment. The results were as follows. 1. When the concentration of $H_2SO_4$ in color reagent exceeds 3.0 m1/100m1 the serum protein precipitated and absorbance increased. 2. The concentrations of antipyrine and diacetylmonoxime required for maximal color formation were 1g/L and 5g/L, respectively. 3. The absorbance was maximal when the reaction mixture was boiled for 25 minutes. 4. The chromogen were stable for at least 60 minutes under loon lighting condition, but decolorized rapidly under direct sunlight. 5. The minimal concentration of urease solution(Sigma Chemical Co., Type III) required for elimination of serum urea was 0, 6mg/ml. 6. When the concentration of L-ornithine solution increased up to 22m moles/L, the ornithine carbamyltransferase activity was not inhibited by zwitterion of ornithine. 7. In accordance with the increase of carbamylphosphate concentration the ornithine carbamyltransferase activity increased and the nonenzymatic citrulline production also increased slightly. 8. The standard curve of citrulline revealed linear pattern within the range of this experiment (0.1~4.0m moles/L). 9. The ornithine carbamyltransferase activities of normal cattle investigated in this laboratory were 6.85$\pm$4.38U/L (mean$\pm$SD) in cows and 2.89$\pm$2.50U/L in bulls. The range of the activities were 0.39~29.12U/L in cows and 0.06~17.34U/L in bulls.

  • PDF

인천 송도4공구 공동주택 외부공간 조성계획 (Landscape Design for the Song-Do Apartment Complex Development)

  • 김도경;안세헌;주신하
    • 한국조경학회지
    • /
    • 제32권5호
    • /
    • pp.119-128
    • /
    • 2004
  • In 2004, the Incheon Urban Development Corporation held a design competition for the Song-Do apartment complex development. Several projects that won the prize in the recent design competitions were reviewed to look around the current design tendency, and current conditions of the site were surveyed. The authors tried to combine digital and environment-friendly factors, considering the site condition. Because the site is on reclaimed land and is located at the center of the information-technology industrial area, these two factors inform the main concept of this project. The site was divided into two different zones : the Ocean Zone and the Digital Zone. The 'community spaces'(community street, community plaza and so on) were designed for the various activities of the residents. The Patios, 'private' community spaces, included many facilities for play, appreciation, rest, exercise, refreshment and gathering. To avoid common landscape styles in the patios, simple and minimal forms were designed. The environmental sculptures were carefully planned, allocated and shaped with digital technology, based on the 'Present and Future of Song-Do'. The authors also tried to introduce environment-friendly factors, such as the green roof system, wall planting, and the water recycling system. This project is following the M.A. (Master Architect) process, and is still being modified to make the hi-tech and environment-friendly apartment complex.

Participation of SRE4, an URE1 Enhancer Core Sequence, in the Sterol-Mediated Transcriptional Upregulation of the Human Apolipoprotein E Gene

  • Min, Jung-Hwa;Paik, Young-Ki
    • BMB Reports
    • /
    • 제31권6호
    • /
    • pp.565-571
    • /
    • 1998
  • The expression of the endogenous human apolipoprotein(apo)E gene was significantly induced when HepG2 cells were treated with exogenous 25-hydroxy-cholesterol. This sterol-mediated apoE gene upregulation appears to require the participation of a positive element for the apoE gene transcription (PET) ( -169/ -140), a core sequence of upstream regulatory element (URE)1 enhancer of the human apoE gene. This PET was renamed as sterol regulatory element (SRE)4 based on its new role as a sensor for the level of intracellular sterol. Furthermore, a gel mobility shift analysis showed that binding activity of the SRE4 binding protein (BP) obtained from HepG2 cells was induced by sterol treatment, while that from either MCF7 or BT20 cells remained unchanged. Binding activity of SRE4BP was also induced in mouse macrophage cells, J774A.1, by sterol treatment, but it was drastically reduced when cells were subjected to treatment of AY-9944, a potent inhibitor for sterol synthesis. However, binding activity of Spl, which is a co-binding protein to the SRE4 region, remained the same in either condition, suggesting that SRE4BP (formally known as PETBP) may be mainly responsible for the sterol-mediated regulation of the apoE gene expression. Deletion analysis of the core binding site of SRE4BP by gel mobility shift assays showed that the minimal sequence of the SRE4BP binding appears to reside between -157 and -140, confirming the identity of SRE4 with the previously determined core sequence of URE1.

  • PDF

Seasonal Variation in Scrotal Circumference and Semen Characteristics of Black Bedouin and Black Bedouin-Damascus Crossbred Bucks

  • Kridli, R.T.;Tabbaa, M.J.;Barakeh, F.S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제20권3호
    • /
    • pp.359-364
    • /
    • 2007
  • The objective of this study was to evaluate monthly variation in semen characteristics in Black Bedouin and Black Bedouin${\times}$Damascus crossbred bucks. Twenty one Black Bedouin Goat bucks (BG) and 20 $F_1$ Black Bedouin${\times}$Damascus crossbred goat bucks (CB) were used in the study. Animals were 2 to 5 years old at the beginning of the study. Body weight (BW), body condition score (BCS), scrotal circumference (SC) and semen samples were evaluated monthly for all bucks. Body weight, BCS and SC differed according to month of collection (p<0.0001). Body weight and BCS were greater in the spring and summer months while SC reached their highest values during the autumn months. No differences were detected between breeds with respect to semen characteristics with the exception of ejaculate volume (p<0.05) and ejaculate appearance (p=0.053) which were greater in CB than in BG bucks. With the exception of ejaculate appearance, all semen characteristics were influenced by month of collection (p<0.05). Semen concentration and motility were better during the late summer and autumn months than during the spring. The percentage of abnormal spermatozoa declined from its greatest values in the spring to its lowest values in the autumn. Results of the present study show no effects of goat breed on most of the studied parameters. In general, most semen quality parameters were better in both breeds during the autumn than the spring months. Minimal variation in semen quality was observed between the summer and autumn months indicating the ability to use bucks for semen collection and for natural breeding during both of these seasons.