• 제목/요약/키워드: Leaf characteristics

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대형트럭 다판 스프링과 테이퍼 판스프링의 진동특성 비교 (Comparison of Vibration Characteristics of a Multi-leaf Spring and a Tapered Leaf Spring of a Heavy Truck)

  • 오재윤;문일동
    • 대한기계학회논문집A
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    • 제29권2호
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    • pp.270-276
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    • 2005
  • This paper develops the flexible computational model of a heavy truck by interfacing the frame modeled as a flexible body to the heavy truck's computational model composed of rigid bodies. The frame is modeled by the finite element method. Three torsional modes and three bending modes of the frame are considered for the interface of the heavy truck's computational model. The actual vehicle test is conducted off road with a velocity of 20km/h. The vertical accelerations at the cab and front axle are measured in the test. For the verification of the developed computational model, the measured vertical acceleration profiles are compared with the simulation results of the heavy truck's flexible computational model. E grade irregular road profile of ISO is used as an excitation input in the simulation. The verified flexible computational model is used to compare the vibration characteristics of a front suspension system having a multi-leaf spring and that having a tapered leaf spring. The comparison results show that the front suspension having a tapered leaf spring has a higher vertical acceleration at the front axle but a lower vertical acceleration at the cab than the suspension system having a multi-leaf spring.

기능성 천연물을 첨가한 스펀지 케이크의 품질 특성(1. 뽕잎 분말) (The Quality Characteristics of Sponge Cake Containing a Functional and Natural Product(1. Mulberry Leaf Powder))

  • 최길용;배종호;한갑조
    • 동아시아식생활학회지
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    • 제17권5호
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    • pp.703-709
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    • 2007
  • The purpose of this study was to investigate the quality characteristics of sponge cake with various amounts of mulberry leaf powder in place of flour. The specific gravity of kneading was maintained at the different amounts of added mulberry leaf powder, which increased at ratios of 5, 10, 15, and 20 percent. The crumb decreased greatly when flour rather than mulberry leaf powder was used. As the amount of mulberry powder increased, red and yellow color decreased in both the crumb and crust. The volume and symmetry indices of the sponge cake slightly decreased when the amount of mulberry powder increased. However, uniformity was not significantly different between the samples. The specific volume of the cake decreased when the amount of the mulberry leaf powder increased. In addition, mulberry leaf powder increased the degrees of hardness and gumminess of cake, but did not show any differences for the cohesiveness and springiness of the cake texture. In the consumer acceptability test, the most favorable taste and odor were attained at the 10 percent level of mulberry leaf powder.

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연잎 분말을 첨가한 쿠키의 품질특성 (Quality Characteristics of Cookies Prepared with Lotus Leaf Powder)

  • 김귀순;박금순
    • 한국식품조리과학회지
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    • 제24권3호
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    • pp.398-404
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    • 2008
  • The purpose of this study was to investigate the quality characteristics of cookies prepared with lotus leaf powder(0,1,3,5,7%) substituted for flour. The pH of the cookie dough decreased significantly at all levels of lotus leaf powder. The highest dough value was 1.25, which occurred in the 1% lotus leaf powder group; however there were no significant differences among the test groups. Upon comparing the spread factor values of samples the results showed there was an inverse relationship with the lotus leaf powder concentration as compared to the control(13.53). In addition, Hunter's color L, a and b values significantly decreased with increasing lotus leaf powder content (p < .001). According to textural measurements, the substitution of $1{\sim}7%$ for flour resulted in increased hardness, cohesiveness, springiness, and brittleness when samples were compared to the control. Finally, based on sensory evaluations results, the color of the cookies increased dose dependently with the lotus leaf powder concentration. And the cookies containing $1{\sim}3%$ had the highest scores.

칡(Pueraria thunbergiana) 조직수분관계의 일변화 특성 (The Characteristics of Diurnal Changes in the Tissue-Water Relations of Pueraria thunbergiana)

  • 박용목;최창렬
    • The Korean Journal of Ecology
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    • 제21권1호
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    • pp.89-96
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    • 1998
  • The diurnal changes of the stomatal conductance, transpiration and leaf water potential were measured in order to assess the water relations characteristics of Pueraria thunbergiana in August of 1995 and 1996. The results showed two different responses depending on the duration of rainless days. The microclimatic conditions were highly stressful on 2 August. Daily maximum temperature reached to $39.0{\circ}C$ and vapor pressure deficit was 3.55 KPa. During this time the leaf water potential decreased to -1.02 MPa and a marked reduction of stomatal conductance was shown. However, on 15 August the stomatal conductance increased with increment of photon flux density, and transpiration was highly maintained during the day time. Minimum leaf water potential was only -0.47 MPa in spite of high transpiration rate. Furthermore, on 15 August reduced leaf water potential during the day time was recovered rapidly with decrease of photon flux density, whereas recovery of leaf water potential on 2 August was delayed. However, reduced leaf water potential on 2 August was recovered untile the next dawn. Osmotic potential at turgor loss point of Pueraria thunbergiana on 2, 3 and 15 August was -1.79, -1.70 and -1.60 MPa, respectively. The vapor pressure deficit is more contributive to the regulation of stomatal conductance than leaf water potential.

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헛개나무 선발개체 차대의 생장 및 엽특성 (Leaf Characteristics and Growth Performance in Progenies of Hovenia dulcis var. koreana Nakai)

  • 김세현;정헌관;장용석;한진규
    • 한국자원식물학회지
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    • 제20권1호
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    • pp.7-11
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    • 2007
  • 우량품종 육성을 위해 선발된 헛개나무 차대묘 20가계의 생장특성과 엽특성을 조사한 결과, 전체 평균 묘고는 61.6cm, 평균 근원직경은 6.98mm였으며, 가계별로는 KW 2-5 가계가 평균 묘고 79.3cm로 가장 우수한 생장을 보인 반면 근원직경에서는 JN 2-2 가계가 평균 9.16mm로 가장 우수한 생장을 나타내었다. 묘고와 근원직경에서 가장 우수한 생장을 보인 KW 2-5와 JN 2-2 가계는 가장 낮은 생장을 보인 가계들과 비교하여 각각 57%와 53%의 우수한 생장을 보였다. 묘고와 근원직경의 초기생장 상위 10% 가계를 선발했을 때 KW 2-5와 JN 2-2 가계가 전체 가계 평균에 비해 125%의 선발 효과를 보였으며, 상위 20% 가계를 선발했을 때 KW 2-5, JN 2-2, KW 1-1, KW 1-15 가계에서 115%의 선발효과를 나타냈다. 한편, 엽장과 엽폭, 엽병길이와 엽병직경 및 엽형지수와 측맥수 등 6항목에 대하여 엽특성을 조사한 결과, 평균 변이계수는 $9.4{\sim}42.4%$로 나타나 변이 폭이 큰것을 알 수 있었으며 특히, 엽병길이와 엽병직경 특성의 변이계수가 각각 42.4%와 28.7%로 다른 특성들에 비해 큰 값을 나타냈다. 조사된 엽특성들은 모두 가계간 유의적 차이가 인정되었으며, 엽장과 엽형지수간 상관을 제외한 모든 특성들간의 상관에서는 정의상관 관계가 인정되었고 특히, 엽장과 엽폭특성간의 상관계수가 0.8049로 나타나 두 특성간에 매우 유의적인 관계가 있는 것으로 나타났다.

스테비아 잎 분말 첨가 오미자편의 품질 특성 및 항산화 특성 (Quality Characteristics and Antioxidant Properties of Omija-pyun (Schisandra chinensis Jelly) added with Stevia Leaf Powder)

  • 박숙현;심기현
    • 한국식품영양학회지
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    • 제30권4호
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    • pp.653-664
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    • 2017
  • This study added stevia leaf powder at ratios of 0.5, 1.0, 1.5, and 2.0 percent to Omija-pyun (Schisandra chinensis Jelly) as a natural low-calorie sweetener instead of sugar which is added to Omija-pyun in considerable amounts to evaluate quality characteristics and antioxidant activities compared to the control group with the addition of sugar. Moisture content of Omija-pyun expanded by increasing the measurement of stevia leaf powder (p<0.001), pH (p<0.01) and sugar content (p<0.001) decreased. L-values and b-values revealed a tendency to increase by adding more stevia leaf powder, but a-value revealed a tendency to decrease (p<0.001). Hardness (p<0.001) and chewiness (p<0.05) decreased by adding more stevia leaf powder. Based on the consumer preference evaluation, Omija-pyun with the addition of 0.5 percent stevia leaf powder was the most preferable in terms of color and flavor (p<0.001). The control group and Omija-pyun with the addition of 0.5 percent stevia leaf powder was the most preferable in terms of taste and texture (p<0.001). There were significant differences in the organoleptic properties except hardness between the samples by quantitative descriptive analysis. The control group revealed the highest preference in terms of redness and transparency, and redness and transparency tended to decrease by adding more stevia leaf powder (p<0.001). Organoleptic properties on bitterness and sourness were enhanced by adding more stevia leaf powder in the principal component analysis (PCA). Regarding antioxidant properties, total phenol compounds and flavonoid contents of Omija-pyun increased by adding more stevia leaf powder, and DPPH radical scavenging capacity also increased (p<0.001). Based on results, it is preferable to serve Omija-pyun with the addition of 1.0 percent stevia leaf powder instead of sugar within the context of quality and antioxidant activity.

스테비아잎 분말로 설탕을 대체한 카스텔라의 품질특성 (Quality Characteristics of Castella Prepared by Substituting Sugar with Stevia Leaf Powder)

  • 최순남;김현정;주미경;정남용
    • 한국식품조리과학회지
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    • 제29권2호
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    • pp.153-160
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    • 2013
  • This study was carried out to evaluate the effects of stevia leaf powder on castella quality. Castellas were prepared by the addition of 0, 3, 6, 9 and 12% stevia leaf powder on sugar. The weight of castellas with stevia leaf powders ranged from 126.0~128.0 g and that of the control was 130.5 g. The volume of the castellas prepared by adding stevia leaf powder was 710.3~745.0 mL and that of the control was 756.3 mL. The height, specific volume of castellas decreased with the addition of stevia leaf powder. The Hunter L and a values of crumb and crust of castellas decreased, whereas b values increased with the addition of stevia leaf powder. The hardness, cohesiveness and chewiness increased with the addition of stevia leaf powder, whereas springiness decreased. The sensory quality of the 6% stevia leaf powder castella tested by flavor, taste, moistness and chewiness was better than that of the control, and overall acceptability of the castella with the addition of 6% stevia leaf powder was the best.

인삼 잎을 첨가한 쿠키의 품질 특성 (Quality Characteristics of Cookies Added with Ginseng Leaf)

  • 김담;김경희;육홍선
    • 한국식품조리과학회지
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    • 제30권6호
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    • pp.679-686
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    • 2014
  • This study was carried out to evaluate the quality characteristics of cookies added with various concentrations (0, 1, 3 and 5%) of ginseng leaf powder. The pH of the cookies significantly decreased with increased ginseng leaf powder concentrations (p<0.05), but the density of cookies showed no significant differences. Spread factor, loss rate, and leaving rate of cookies decreased according to the amount of added ginseng leaf powder. The lightness and yellowness of cookies decreased as the concentration of the ginseng leaf powder increased whereas no significant difference in the redness was found with increased ginseng leaf concentration. In the texture analysis, the hardness of the cookies increased according to the concentration of ginseng leaf. DPPH free radical scavenging activity of the cookies significantly increased with increased ginseng leaf concentration (p<0.05). In the sensory evaluation, sensory scores for color, taste and overall acceptability were highest in the 3% ginseng leaf cookies. Thus, our results suggested that the optimum amount of ginseng leaf powder to add to cookies was 3%.

고려인삼의 화서, 화촉, 과실 및 엽의 형태학적 특성 (Morphological Characteristics of Inflorescence, Flowering Bud, Fruit and Leaf of Korean Ginseng)

  • 최광태;신희석
    • Journal of Ginseng Research
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    • 제6권1호
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    • pp.67-74
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    • 1982
  • To clarify the morphological characteristics of Korean ginseng cultivated, the shapes and frequencies of Inflorescence, flowering bud, fruit, and leaf were investigated. The shapes of inflorescence, flowering bud and fruit, and leaf were divided into 6, 3, and 7 groups, respectively. The frequencies of these shapes were not significantly different according to the planting positions.

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다변량 분석에 의한 국내산 대추나무 품종의 형태적 특성과 유연관계 (Morphological Characteristics and Classification of Zizyphus Cultivars in Korea by Multivariative Analysis)

  • 이문호;황석인;장용석
    • 한국자원식물학회지
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    • 제19권1호
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    • pp.105-111
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    • 2006
  • 대추나무에 관한 연구 및 2008년부터 시행될 산림수종의 품종보호제도에 대비하여 대추나무의 특성조사요령검정지침서(TG : Test guidelines) 작성 등에 활용할 수 있는 기초자료를 제공하고자 우리나라에서 가장 많이 재배되고 있는 대추나무 복조 등 5품종을 대상으로 과실과 엽의 형태적 특성들을 조사, 주성분분석 및 군집분석 등과 같은 다변량 분석법을 이용하여 분석 고찰한 결과, 인(仁)과 관련된 특성에서는 유의성이 인정되지 않아 대추나무의 품종간 유연관계를 고찰하는 특성으로는 부적절 한 것으로 판단된다. 과실중량을 비롯한 모든 특성들에서 보은대추 품종이 복조를 비롯한 다른 4품종과는 형태적 특성에서 명확하게 구분되는 것으로 나타났다. 주성분분석 결과, 제1주성분의 고유값은 10.45로 전체 분산에 대하여 65.3%의 기여도가 있는 것으로 분석되었으며, 고유 값이 1이상인 제3주성분까지의 전체 분산에 대한 기여도는 96.5%로 매우 높은 것으로 나타났다. 특히, 과실종경을 비롯하여 엽장과 엽병장 및 정엽장과 정엽폭, 과형지수와 핵형지수 및 정엽형지수와 같은 형태적 특성들이 대추나무 품종의 유연관계를 구명하는데 높은 기여도를 나타내는 것으로 분석되었다. 군집분석 결과, 거리수준 3.3을 기준으로 보은대추를 제외한 무등과 월출 및 금성과 복조품종이 포함된 I group과 보은대추 품종만이 포함된 II group등 크게 2개의 group으로 구분할 수 있었으며 I group은 무등과 월출 및 복조품종이 포함된 sub group과 금성 품종 등 2개의 sub group으로 다시 구분할 수 있었다.