• Title/Summary/Keyword: internal force

Search Result 997, Processing Time 0.027 seconds

The Relationship between Fat Level and Quality Properties of Ground Pork Patties Cooked by Microwave Energy (전자레인지 가열시 분쇄 돈육 패티의 지방함량과 가열특성과의 상관관계에 관한 연구)

  • Choi, Ji-Hyun;Jeong, Jong-Youn;Choi, Yun-Sang;Lee, Eui-Soo;Kim, Cheon-Jei
    • Food Science of Animal Resources
    • /
    • v.28 no.3
    • /
    • pp.295-300
    • /
    • 2008
  • This study was carried out to elucidate the relationship between different fat levels (0%, 5%, 10%, 15%, 20%, and 25%) and the quality of ground pork patties cooked to reach an internal temperature of $75^{\circ}C$ in a microwave oven. The relationship between fat level and cooking rate of pork patties cooked by microwave energy was highly significant ($R^2=0.72$), and had a low determination coefficient ($R^2=0.55$). The relationship between fat level and total cooking loss of pork patties cooked by microwave energy was also very significant, with a high correlation coefficient of $R^2=0.89$. The correlation coefficient between fat level and cooking drip loss of patties cooked by microwave energy was 0.92, which was highly significant. Although the correlation coefficient between fat level and evaporation loss had a negative value ($R^2=-0.63$), there was a highly significant relationship between fat level and shear force of pork patties cooked by microwave energy.

Dynamic Suppression Effects of Liquid Container to the Baffle Number and Hole Diameter (배플개수 및 내경변화에 따른 액체 저장탱크의 동억제 효과)

  • 조진래;김민정;이상영;허진욱
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.15 no.1
    • /
    • pp.147-154
    • /
    • 2002
  • The dynamic load caused by sloshing of internal fluid severely affects the structural and control stabilities of cylindrical liquid containers accelerating vertically. If the sloshing frequency of fluid is near the frequency of control system or the tank structure, large dynamic force and moment act on launching vehicles. For the suppression of such dynamic effects, generally flexible ring-type baffles are employed. In this paper, we perform the numerical analysis to evaluate the dynamic suppression effects of baffle. The parametric analysis is performed with respect to the baffle inner-hole diameter and two different baffle spacing types : equal spacing with respect to the tank and one with respect to the fluid height. The ALE (arbitrary Lagrangin-Eulerian) numerical method is adopted for the accurate and effective simulation of the hydrodynamic interaction between fluid and elastic structure.

Characteristics of Heat Transfer of Natural Convection for Magnetic Fluids in Annular Pipes (이중원관내 자성유체의 자연대류에 대한 전열특성)

  • Park, J.W.;Jun, C.H.;Seo, L.S.;Ryu, S.O.
    • Journal of the Korean Magnetics Society
    • /
    • v.12 no.2
    • /
    • pp.73-79
    • /
    • 2002
  • Compared with Newtonial fluids, magnetic fluids have effects on magnetic force. In this study, the purpose is to research the heat transfer characteristic of magnetic fluids which have metalic and fluid characteristics as the external pipe is being cooled and internal pipe is heated. This study found the experimental results from the study of the variety of natural convection for magnetic fluids and the characteristics of the heat transfer by using numerical analysis according to the strength and direction of the magnetic fields from being imposed from the outside. Natural convection of magnetic fluids was controlled by the impressed magnetic fields, and the result of mean nusselt number was calculated. If the impressed magnetic field is in the direction of gravity or the strength of impressed magnetic field is more than -14 mT in the opposite direction, the heat transfer is more than that without the impressed magnetic field. If the strength of impressed magnetic field is less than -14 mT in the opposite direction, it is smaller than that without the impressed magnetic field. Especially, when the strength of the magnetic field is -14 mT, the heat transfer was at the minimum.

Experimental Study on Liquid Desiccant Distribution Characteristics at a Dehumidifier with Extended Surface (확장표면을 적용한 액체식 제습기에서 제습액 분배 특성에 관한 실험적 연구)

  • Lee, Min-Su;Chang, Young-Soo;Lee, Dae-Young
    • Proceedings of the SAREK Conference
    • /
    • 2009.06a
    • /
    • pp.645-649
    • /
    • 2009
  • Liquid desiccant cooling technology can supply cooling by using waste heat and solar heat which are hard to use effectively. For compact and efficient design of a dehumidifier, it is important to sustain sufficient heat and mass transfer surface area for water vapor diffusion from air to liquid desiccant on heat exchanger. In this study, the plate type heat exchanger is adopted which has extended surface, and hydrophilic coating and porous layer coating are adopted to enhance surface wettedness. PP(polypropylene) plate is coated by porous layer and PET(polyethylene terephthalate) non-woven fabric is coated by hydrophilic polymer. These coated surfaces have porous structure, so that falling liquid film spreads widely on the coated surface foaming thin liquid film by capillary force. The temperature of liquid desiccant increases during dehumidification process by latent heat absorption, which leads to loss of dehumidification capacity. Liquid desiccant is cooled by cooling water flowing in plate heat exchanger. On the plate side, the liquid desiccant can be cooled by internal cooling. However the liquid desiccant on extended surface should be moved and cooled at heat exchanger surface. Optimal mixing and distribution of liquid desiccant between extended surface and plate heat exchanger surface is essential design parameter. The experiment has been conducted to verify effective surface treatment and distribution characteristics by measuring wall side flow rate and visualization test. It is observed that hydrophilic and porous layer coating have excellent wettedness, and the distribution can be regulated by adopting holes on extended surface.

  • PDF

Flexural Behavior of External Prestressed H-Beam (외부 긴장된 H형 보의 휨거동 특성)

  • Yang, Dong Suk;Lim, Sang Hun;Park, Sun Kyu
    • Journal of Korean Society of Steel Construction
    • /
    • v.14 no.1
    • /
    • pp.79-85
    • /
    • 2002
  • Recently, prestressed H-Beam bridges with external unbonded Tendons are increasingly built. The mechanical behavior of prestressed steel H-beams is different from that of normal bonded PSC beams in a point of the slip of tendons at deviators and the change of tendon eccentricity that occurs, when service load are applied in external unbonded steel H-beams. The concept of prestressing steel structures has been widely considered, in spite of long and successful history of prestressing concrete members. In the study, The flexural test on prestressed steel H-beams has been performed in the various aspects of prestressed H-beam including the tendon type and profile. The load was plotted against the deflection and the strain respectively in the steel beam and prestressing bars. The value expected with the equation of internal force equilibrium and compatibility between the deflection of the bars and the H-beam was found to correlate well with the measured data.

A study on the difference of Ceramic fracture strength according to the metal depth (금속의 두께가 도재의 파절강도에 미치는 영향)

  • Shin, Mu-Hak;Choi, Un-Jae;Kim, Yoong-Won
    • Journal of Technologic Dentistry
    • /
    • v.27 no.1
    • /
    • pp.89-95
    • /
    • 2005
  • In the manufacture of ceramo-metal crown, difference of fracture strength according to the metal depth has been known to be an important influence on enough intensity and internal stress to endure an occlusion-pressure as well as aesthetics of rehabilitating similar colour such as natural teeth. Depth of ceramic material could be determined by that of metal in three groups: first case of thin depth, second case of thick depth, and third case of constant depth. For the enhancement of the fracture strength between metal and ceramic materials and aesthetic satisfaction, a study on the bonding force, fracture strength, and aesthetics have been required more. In this study, therefore metal coping were made in three groups of A, B and C by using both ceramic powder of Norithe and metal of Columbium, which have been used primarily in the market. A group was made in $0.2mm\times10mm\times10mm$, B group was made in $0.4mm\times10mm\times10mm$, and, C group was made in $0.8mm\times10mm\times10mm$, respectively. The number of metal coping in each group was 10, and total sample numbers used in this study were 30 metal copings. After these metal coping tissue were in the process of build-up in 1.5mm constant depth of porcelain, firing, and glazing, the fracture strength about each metal coping tissue was investigated using oil press. It was found that the average values of durable occlusion pressure for separation of ceramic material in the porcelain fused to metal crown (PFM) in the each group showed the increasing order of A group (30 bar), B group (42 bar), and C group (44 bar), respectively. Proper depth of metal coping in the PFM was considered to be 0.4mm in the B group because this metal size showed higher durable property to the occlusion pressure and better coupling strength in the ceramo-metal crown.

  • PDF

Design and analysis of slotted shear walls equipped with energy dissipating shear connectors

  • Shen, Shaodong;Nie, Xin;Pan, Peng;Wang, Haishen
    • Computers and Concrete
    • /
    • v.20 no.5
    • /
    • pp.539-544
    • /
    • 2017
  • Shear walls have high stiffness and strength; however, they lack energy dissipation and repairability. In this study, an innovative slotted shear wall featuring vertical slots and steel energy dissipation connectors was developed. The ductility and energy dissipation of the shear wall were improved, while sufficient bearing capacity and structural stiffness were retained. Furthermore, the slotted shear wall does not support vertical forces, and thus it does not have to be arranged continuously along the height of the structure, leading to a much free arrangement of the shear wall. A frame-slotted shear wall structure that combines the conventional frame structure and the innovative shear wall was developed. To investigate the ductility and hysteretic behavior of the slotted shear wall, finite element models of two walls with different steel connectors were built, and pushover and quasi-static analyses were conducted. Numerical analysis results indicated that the deformability and energy dissipation were guaranteed only if the steel connectors yielded before plastic hinges in the wall limbs were formed. Finally, a modified D-value method was proposed to estimate the bearing capacity and stiffness of the slotted shear wall. In this method, the wall limbs are analogous to columns and the connectors are analogous to beams. Results obtained from the modified D-value method were compared with those obtained from the finite element analysis. It was found that the internal force and stiffness estimated with the modified D-value method agreed well with those obtained from the finite element analysis.

Predictors Affecting Breast Self-Examination Practice among Turkish Women

  • Doganer, Yusuf C.;Aydogan, Umit;Kilbas, Zafer;Rohrer, James E.;Sari, Oktay;Usterme, Necibe;Yuksel, Servet;Akbulut, Halil;Balkan, Salih M.;Saglam, Kenan;Tufan, Turgut
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.20
    • /
    • pp.9021-9025
    • /
    • 2014
  • Background: Breast cancer (BC) is the most common cancer among females in Turkey. Predictors affecting the breast self-examination (BSE) performance vary in developing countries. Objective: To determine the frequency of BSE performance and predictors of self-reported BSEs among women in the capital city of Turkey. Materials and Methods: This cross-sectional study was conducted on 376 Turkish women using a self-administered questionnaire covering socio-demographic variables and BSE-related features. Results: Of the participants, 78.7% (N=296) reported practicing BSE, whereas 9.5% (N=28) were implementing BSE regularly on a monthly basis, and only 5.7% (N=17) were performing BSE regularly within a week after each menstrual cycle. Multivariate logistic regression modeling revealed that BSE performance was more likely in younger age groups [20-39 years] (p=0.018, OR=3.215) and [40-49 years] (p=0.009, OR=3.162), women having a family history of breast disease (p=0.038, OR=2.028), and housewives (p=0.013, OR=0.353). Conclusions: Although it appears that the rates of BSE performers are high, the number of women conducting appropriate BSE on a regular time interval basis is lower than expected. Younger age groups, family history of breast diseases and not being employed were identified as significant predictors of practicing BSE appropriately. Older age and employment were risk factors for not performing BSE in this sample.

Numerical analysis of turbulent flows in the helically coiled pipes of heat transfer (열교환기의 나선형 관내 난류유동 수치해석)

  • Kwag, Seung-Hyun
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.37 no.8
    • /
    • pp.905-910
    • /
    • 2013
  • The flow analysis has been made by applying the turbulent models in the helically coiled tubes of heat transfer. The k-${\varepsilon}$ and Spalart-Allmaras turbulent models are used in which the structured grid is applied for the simulation. The velocity vector, the pressure contour, the change of residuals along the iteration number and the friction factors are simulated by solving the Navier-Stokes equations to make clear the Reynolds number effect. The helical tube increases the centrifugal forces by which the wall shear stress become larger on the outer side of the tube. The centrifugal force makes the heat transfer rate locally larger due to the increase of the flow energy, which finds out the close relationship between the pressure drop and friction factor in the internal flow. The present numerical results are compared with others, for example, in the value of friction factor for validation.

Computation of Dynamic Fluid-Structure Interaction in a 2-Dimensional Laminar Channel Flow Divided by a Plate (판으로 나뉘어진 2차원 충류 채널유동에서 동적 유체-구조물 상호작용 수치해석)

  • Namkoong, Kak;Choi, Hyoung-Gwon;Yoo, Jung-Yul
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.26 no.12
    • /
    • pp.1738-1746
    • /
    • 2002
  • In the FSI (Fluid-Structure Interaction) problems, two different governing equations are to be solved together. One is fur the fluid and the other for the structure. Furthermore, a kinematic constraint should be imposed along the boundary between the fluid and the structure. We use the combined formulation, which incorporates both the fluid and structure equations of motion into a single coupled variational equation so that it is not necessary to calculate the fluid force on the surface of structure explicitly when solving the equations of motion of the structure. A two-dimensional channel flow divided by a Bernoulli-Euler beam is considered and the dynamic response of the beam under the influence of channel flow is studied. The Navier-Stokes equations are solved using a P2P1 Galerkin finite element method with ALE (Arbitrary Lagrangian-Eulerian) algorithm. The internal structural damping effect is not considered in this study and numerical results are compared with a previous work fer steady case. In addition to the Reynolds number, two non-dimensional parameters, which govern this fluid-structure system, are proposed. It is found that the larger the dynamic viscosity and density of the fluid are, the larger the damping of the beam is. Also, the added mass is found to be linearly proportional to the density of the fluid.