• Title/Summary/Keyword: Relative stability

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Effect of Storage Temperature and Humidity on the Quality Stability of Potatoes (감자의 품질안정성에 대한 저장 온.습도의 영향)

  • 권중호;변명우
    • Food Science and Preservation
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    • v.2 no.2
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    • pp.243-249
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    • 1995
  • Potatoes, Irish cobbler, were subject to quality evaluation from the physiological and physicochemical points of view during storage under different temperatures and relative humidities for 11 months. Quality criteria were sprouting, rotting, weight changes, moisture, total sugar, reducing sugar and vitamin C. Low temperature condition(LT, 2∼4$^{\circ}C$, 80% RH) was enough to preserve Potatoes for 11 months, but it was indicated to be limitations that the increase in reducig sugar as well as sprouting by about 3.3 to 6.7% occurred from the 3rd month of storage. Meanwhile, pit temperature(PT, 3∼15$^{\circ}C$, 75∼85% RH), room temperature(RT, 7∼17$^{\circ}C$, 80∼95% RH) and ambient temperature(AT, 2∼25$^{\circ}C$, 62∼72 RH) were shown infeasible conditions for the storage of potatoes mainly due to the increase In sprouting-rate and subsequent quality-loss after 3 months of storage. Based on the results, it proposed that more economical conditions, ranging 10 to 15$^{\circ}C$ and about 80% RH following sprout inhibition treatment should be used for the long-term storage of potatoes.

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Calculation of Interaction Parameters in Mixed Layer Minerals and their Application (층상형 혼합광물의 상호작용계수의 계산 및 응용)

  • 이성근;김수진
    • Journal of the Mineralogical Society of Korea
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    • v.10 no.2
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    • pp.97-104
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    • 1997
  • Based on the method of determination for relative stability of each phase from the difference among the interaction parameters of the phases consisting the mixed layer, the types of interactions between layers were specified and interaction parameter between layers in ordered domain was analytically derived as a function parameter between layers in ordered domain was analytically derived as a function of not only temperature and mole fraction of layers but also ordering parameter. Interaction parameter between the different layers in ordered phase, L is as follows:{{{{ {L }_{1 } (X,Q,T)= { C} over { Q} -4(1-2Q) { L}^{2 } - { RT} over {2} ln { 1} over {2 } - { 2RT} over { { X}_{ s} } ln { { 4QX}`_{s } ^{2 } } over {(1- { X}_{s }- { QX}_{s })( { X}_{s }- {QX }_{s } ) } }}}}L2 is the interaction parameter between ordered and disordered phase in domain and is the mole fraction of the domain which represent the infinite length of mixed layer mineral and Q and C are the reaction progress parameter and arbitrary constant, respectively. This equation was used for the I/S mixed layer clay minerals to infer the relative stability of R1 type I/S mixed layer in the temperature range from 373K to 450K. The result of calculation suggest that, owing to the decrease in interaction parameter with increasing temperature. The interaction parameter decreases more rapidly with decreasing mole fraction of smectite in domain, which is consistent with the fact that the probability of finding the series smectite layer is lo in the domain with small mole fraction of smectite layers in natural system.

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Relative Slope - stability Mapping in the Southeastern Part of Korea Using GIS (GIS를 이용한 한국 동남부지역의 상대적 사면안정성 분류도 작성)

  • 한대석;이사로;김경수;최영섭;유일현
    • Spatial Information Research
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    • v.6 no.1
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    • pp.25-33
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    • 1998
  • The study region encompasses about 5,900$km^2$ including the topographic maps of Kimhae, Pusan, Miryang, Yangsan, Panguhjin, Tonggok, Uhnyang, Ulsan, Youngchon, Kyongju, Pulguksa, and Kampo, all at a scale of 1:50,000. The paper discusses how to have prepared the four thematic maps, landslide and unstable slope distribution map, slope classification amp, soil classification map, and lineament density map. Using all the above maps and GIS, the relative slope-stability map for the study regiun was produced at a scale of 1:100,000 ; the map can be utilized for the regional land-use planning in the study region.

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The Study on Storage Stability according to Packaging Material of Traditional Sesame Dasik (깨다식의 포장재에 따른 저장성 조사)

  • 김진숙;한영실
    • The Korean Journal of Community Living Science
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    • v.15 no.2
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    • pp.179-187
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    • 2004
  • The purpose of this study is to investigate the preservation of traditional sesame dasik when stored in different packaging material by comparing its physical and sensorial characteristics. The quality and sensory characteristics of sesame dasik that were evaluated were moisture content, water activity, number of microflora, texture profile, Hunter color different value, and sensory properties (color, chewiness, overall acceptability, etc) during the storage at 35\pm1^\circ{C}$ temperature and $73\pm{2%}$ relative humidity. And the packaging materials were paper boxes (coated 0.02mm thickness polyethylene film), plastic boxes, and oriented polypropylene laminated film. Traditional sesame dasik is made from sesame powder 100g, honey 25g, rice syrup 25g, and table salt 0.5g. During the storage period, the changes in water content and water activity of sesame dasik with different packaging material showed a slight decline. On the other hand, it increased in hardness, and "a" and "b" value of Hunter color difference during the storage. Texture profile analysis data change in hardness was the greatest after the third day in a paper box, and it was affected by the moisture content of dasik and the temperature and relative humidity of the air. Therefore plastic boxes or oriented polypropylene laminated film was found to be better suited than paper boxes for storing sesame dasik.

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Linear Stability Analysis of an Out-of-plan Motion of Vibration of a Two Degree-of-freedom with Contact Stiffness (마찰기인 접촉 강성을 가지는 2-자유도계 면외 방향 진동 시스템의 선형 안정성 해석)

  • Joe, Yong-goo;Shin, Ki-hong;Lee, Hyun-young;Oh, Jae-Eung;Lee, Su-Gab
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.3 s.96
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    • pp.259-265
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    • 2005
  • A two-degree-of-freedom out-of-plane model with contact stiffness is presented to describe dynamical interaction between the pad and disc of a disc brake system. It is assumed that the out-of-plane motion of the system depends on the friction force acting along the in-plane direction. Dynamic friction coefficient is modelled as a function of both in-plane relative velocity and out-of-plane normal force. When the friction coefficient depends only on the relative velocity, the contact stiffness has the role of negative stiffness. The results of stability analysis show that the stiffness of both pad and disc is equally important. Complex eigen value analysis is conducted for the case that the friction coefficient is also dependent on the normal force. The results further verify the importance of the stiffness. It has also been found that increasing the gradient of friction coefficient with respect to the normal force makes the system more unstable.

Analysis of Out-of-plane Motion of a Disc Brake System Considering Contact Stiffness (접촉 강성을 고려한 디스크브레이크의 면외진동 해석)

  • Joe, Yong-Goo;Oh, Jae-Eung;Shin, Ki-Hong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.597-600
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    • 2004
  • A two-degree-of-freedom out-of-plane model with contact stiffness is presented to describe dynamical interaction between the pad and disc of a disc brake system. It is assumed that the out-of-plane motion of the system depends on the friction force acting along the in-plane direction. Dynamic friction coefficient is modelled as a function of both in-plane relative velocity and out-of-plane normal force. When the friction coefficient depends only on the relative velocity, the contact stiffness has the role of negative stiffness. The results of stability analysis show that the stiffness of both pad and disc are equally important. Complex eigenvalue analysis is conducted for the case that the friction coefficient is also dependent on the normal force. The results further verify the importance of the stiffness. It has also been found that increasing the gradient of friction coefficient with respect to the normal force makes the system more unstable. Nonlinear analysis is also performed to demonstrate various responses. Comparing the responses with experimental data has shown that the proposed model may qualitatively well represent a certain type of brake noise.

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Fabrication and Characteristics of Y-TZP/Ce-TZP Structural Ceramics (Y-TZP/Ce-TZP 구조세라믹스의 제조 및 특성연구)

  • 이종현;이윤복;김영우;오기동;박흥채
    • Journal of the Korean Ceramic Society
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    • v.33 no.10
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    • pp.1177-1185
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    • 1996
  • Y-TZP/Ce-TZP ceramics having relative sintered densities of>95% average grain sizes of 0.36$\mu\textrm{m}$ microhar-dness of 1150 kg/mm2 fracture strength of 390-830 MPa and toughness of 6.4-10.2 MPa$.$mm1/2 were prepared by conventional sintering of 3 mol% Y2O3-ZrO2 and 12 mol% CeO2-ZrO2 powders at 1400 and 1500$^{\circ}C$ The average grain sizes of Y-TZP/Ce-TZP ceramics were mainly governed by those of Ce-TZP. White increasing Ce-TZP content toughness increased while microhardness and fracture strength decreased. With comparing microhardness and toughness fracture strength was more sensitive on not only grain size but also other factors such as microstructural and compositional variations. The densification of Y-TZP/Ce-TZP cermaics was not greatly affected by composition and soaking time at temperature over 1400$^{\circ}C$ With increasing CE-TZP content the stability of t-ZrO2 decreased under thermal aging in air whereas increased in hydrothermal atmosphere and aqueous solution.

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A Connection Entropy-based Multi-Rate Routing Protocol for Mobile Ad Hoc Networks

  • Hieu, Cao Trong;Hong, Choong-Seon
    • Journal of Computing Science and Engineering
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    • v.4 no.3
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    • pp.225-239
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    • 2010
  • This paper introduces a new approach to modeling relative distance among nodes under a variety of communication rates, due to node's mobility in Mobile Ad-hoc Networks (MANETs). When mobile nodes move to another location, the relative distance of communicating nodes will directly affect the data rate of transmission. The larger the distance between two communicating nodes is, the lower the rate that they can use for transferring data will be. The connection certainty of a link also changes because a node may move closer to or farther away out of the communication range of other nodes. Therefore, the stability of a route is related to connection entropy. Taking into account these issues, this paper proposes a new routing metric for MANETs. The new metric considers both link weight and route stability based on connection entropy. The problem of determining the best route is subsequently formulated as the minimization of an object function formed as a linear combination of the link weight and the connection uncertainty of that link. The simulation results show that the proposed routing metric improves end-to-end throughput and reduces the percentage of link breakages and route reparations.

A POSTEROANTERIOR ROENTGENOCEPHALOMETRIC STUDY OF SKELETAL CRANIOFACIAL ASYMMETRIC PATIENTS (골격형 안면 비대칭 부정교합자에 대한 정모두부방사선 계측학적 연구)

  • Cheon, Ok-Jin;Suhr, Cheong-Hoon
    • The korean journal of orthodontics
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    • v.20 no.3 s.32
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    • pp.565-581
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    • 1990
  • This study was undertaken to investigate the degree of asymmetry in each part of the head in skeletal craniofacial asymmetric patients, and secondarily to determine the nature of difference existed between asymmetric patients and normal persons. The subjects consisted of 49 asymmetric adult patients and 52 normal adults, and the average ages were 21 years 5 months and 23 years 5 months, respectively. The computerized analyses of 33 linear measurements, 12 angular measurements, and 8 surface areas from posteroanterior cephalometric radiograph were carried out. The conclusions were as follows; 1. Asymmetry was a common finding in both normal and asymmetric group. 2. When the analyses were undertaken after the head was divided into 3 parts anteroposteriorly and superoinferiorly in the asymmetric patients, there were significant asymmetries in all parts excepts in the cranial base region. 3. When the analyses were undertaken after the head was divided into respective 3 parts anteroposteriorly in the asymmetric patients, the more posterior part showed relative stability than the more anterior part. 4. When the analyses were undertaken after the head was divided into 3 parts superoinferiorly in the asymmetric patients, the more superior part showed relative stability than the more inferior part. 5. Twelve variables indicating asymmetry were selected and the highest ranked variable was Me-Mid-sagittal reference line.

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A Study on the 'a' index of Sound source for Productivity improvement (생산성향상을 위한 음원의 a지수에 관한 연구)

  • Yoo, Young-Jo;Kim, Myung-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.547-554
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    • 2014
  • In this study, have researched 'a' index from three sound sources, effects on subject and finding optimal 'a' index, which can improve subject's stability, concentration and productivity. Check the health status of subjects who were selected 5 male and 5 female university students, and the period of this experiment was about two months. It were measured each subject's EEG, HRV and vibra image to analyze transition of stability, concentration, stress and heart beat. The results was measured in an environmental test room of temperature $25[^{\circ}C]$, the relative humidity 50 [%], illuminance 1,000 [lux] and air current speed 0.02[m/sec] with 'a' index of three sound sources which are a=1.106, a=1.749 and a=2.227. Results in a=1.106 compared to before exposure, relative $S{\alpha}$ wave, relative $L{\beta}$ wave and relative $M{\beta}$ wave have been revitalized, asymmetry index, stress and HRV have been decreased. Thus, to increase stability, concentration and productivity, also to decrease stress, changes in sound source of a=1.106 was found to be the most effective.