• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.5
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• pp.532-538
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• 2004

MEMS technology applying to the sensors and micro-electro devices is complete system. These microsystems are made by variable processes. Especially, the mentallization process has very important functions to transfer the power operating the sensor and signal induced from sensor part. But in the structures of MEMS the local stress concentration and deformation are often yielded by an irregular geometrical shape and different constraint. Therefore, this paper studies the effect of supporting type and thickness ratio about thin film of the substrate on the residual stress variation when the thermal loads is applied to the multi-layer thin film fabricated by metallization process. Specimens were made from several materials such as Al, Au and Cu. Then, uniform thermal load was applied, repeatedly. The residual stress was measured by FE Analysis and nano-indentation method using AFM. Generally, the specimen made of Al induced the larger residual stress than that of made of other materials. Specimen made of Cu and Au having the low thermal expansion coefficient induces the minimum residual stress. Similarly, the lowest indentation length was measured by nano-indentation method in the Si/Au/Cu specimen. Particularly, clusters are created in the specimen made of Cu by thermal load and the indentation length became increasingly large by cluster formation.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.2
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• pp.247-253
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• 2002

Two experiments were conducted to investigate the impact of high temperature and dietary tryptophan (Trp) on performance, selected organ weights and plasma free amino acid (AA) concentrations in broiler chickens. In Experiment 1, exposure to $27-33^{\circ}C$ of chickens for 2 weeks from 2 weeks of age did not affect growth and plasma free AA concentration except for a decrease in the concentration of plasma tyrosine (Tyr). In Experiment 2, 2-week-old birds were allocated to one of three temperature treatments; $24^{\circ}C$ (control), $36^{\circ}C$ (heat stress, HS) and $24^{\circ}C$ pair-fed (24PF) for 2 weeks and fed on diets containing 50, 100 and 300% of NRC requirement for Trp. Heat stress caused a reduction of weight gain and feed intake irrespective of dietary Trp levels compared with control counterparts, while feeding of 300% Trp diet did not attenuate the reduced performance by HS exposure. In groups fed the 100% Trp diets, plasma aromatic AA (AAA) and Tyr concentrations were decreased in the HS birds compared with the 24PF group. Plasma concentrations in most of AA groups were increased by HS in chickens fed the 50% Trp diet, while those were not changed by HS in chickens fed the 300% Trp diet, compared with 24PF counterparts. The plasma Trp/LNAA (LNAA=large neutral AAs, which are comprised of BCAA, AAA and Trp) ratio was increased by HS in chickens fed the 100% Trp diet, while it was decreased in chickens fed on 50% Trp diet as compared with 24PF group. From these results, it is suggested that performance and plasma amino acid profile deranged by heat stress are modulated, at least, to be relieved from the heat stress by feeding 50% Trp diet but not at all by feeding 300% Trp diet. The involvement of altered plasma AA profiles, in particular plasma Tyr concentrations and Trp/LNAA ratio, is discussed in association with the performance characteristics of HS chickens.

• Steel and Composite Structures
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• v.20 no.4
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• pp.889-911
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• 2016

Using the hyperbolic shear deformation plate model and including plate-foundation interaction (Winkler and Pasternak model), an analytical method in order to determine the deflection and stress distributions in simply supported rectangular functionally graded plates (FGP) subjected to a sinusoidal load, a temperature and moisture fields. The present theory exactly satisfies stress boundary conditions on the top and the bottom of the plate. No transversal shear correction factors are needed because a correct representation of the transversal shearing strain is given. Materials properties of the plate (elastic, thermal and moisture expansion coefficients) are assumed to be graded in the thickness direction according to a simple power-law distribution in terms of the volume fractions of the constituents. Numerical examples are presented and discussed for verifying the accuracy of the present theory in predicting the bending response of FGM plates under sinusoidal load and a temperature field as well as moisture concentration. The effects of material properties, temperature, moisture, plate aspect ratio, side-to-thickness ratio, ratio of elastic coefficients (ceramic-metal) and three distributions for both temperature and moisture on deflections and stresses are investigated.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.4
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• pp.297-301
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• 2001

In this paper, the temperature distribution and thermal stress analysis of 50kVA pole cast resin transformer for power distribution are investigated by FEM program. The one body molding model (Model 1) and air duct model (Model 2) are designed and their temperature distribution are analysed. The temperature rise value is about 105.5 deg in the model 1 and 65.28 de in the model 2. The temperature change of secondary winding is more than primary winding according to load ratio. The concentration part of Von Mises Stress occurs at interface between glass fiber and epoxy.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.1
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• pp.71-78
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• 2002

In this study, the influence of the presence of discontinuity planes on the load transfer mechanism and the pattern of loosening zone was studied based on the laboratory test. The trap-door and the reaction plates are installed as the bottom plane of the model box. The vertical discontinuity plane is installed in the dry sand. Various overburden heights and locations of discontinuity planes are applied as major factors in this study. The results show that at higher overburden heights over about 1.5 times the excavation width, the ratio of the transferred stress to the insitu stress converges to a certain value even if the overburden height increases further. The results also show that the discontinuity plane gives relatively larger influence on the load transfer mechanism, that produces the unsymmetrical load concentration, when the discontinuity plane locates within the tunnel width. When the discontinuity plane locates outside the tunnel width, the unsymmetrical load concentration is reduced considerably.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.1
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• pp.55-60
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• 1988

A two year's field experiment was conducted on newly reclaimed saline tidal lands to measure the effects of sand mulching on salinity of the soils and their relationship to crop performance. Hybrid sorghum cv. Pioneer 931 was grown under different mulching treatments using of medium sand and red earth (Fine loamy, Typic Hapludults). Salinity in the root zone was decreased markedly under soil mulching using of medium sand, especially during the dry season, and it caused a great increase in the root growth and R/T ratio. Seasonal values of electrical conductivity at sand mulching were 6.6 in April and 1.6 mmhos in August, but it was still high with a concentration of 12.7 (April) and 3.8 mmhos (August) in untreated check plot. Sand mulching increased plant growth and the rate of dry matter accumulation. However, treatment of red earth additionally over sand mulching produced lower dry matter yield than those of soil mulching using of medium sand only. Under salt stress sorghum plant showed a decrease in the leaf weight ratio (LWR) and it resulted in a low concentration of crude protein of the plant. Sand mulching enhanced leaf weight ratio and rate of protein synthesis.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.4
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• pp.509-516
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• 2011

The performance of naked neck and normal chicken was evaluated with respect to growth, carcass, immune, biochemical and stress parameters under winter and summer seasons to assess the suitability of naked neck birds under high temperatures in the global scenario of climate change. The growth performance was significantly ($p{\leq}0.05$) higher in naked neck chicken in the summer season. The dressing percentage was significantly ($p{\leq}0.05$) higher in naked neck birds in both winter and summer season because of reduced plumage. The thigh, giblet and feather proportion significantly ($p{\leq}0.05$) varied between naked neck and normal chickens in summer season. The humeral immune response to sheep red blood cells (SRBC), Newcastle disease vaccine (NDV) and cutaneous basophil hypersensitivity (CBH) did not show any significant differences among the chicken groups. The protein and cholesterol concentration observed was within the normal ranges. The total cholesterol levels in plasma were significantly ($p{\leq}0.05$) lower in naked neck birds in both the seasons. H:L ratio was significantly ($p{\leq}0.05$) lower in summer season indicating less stress in naked neck chicken. Basophil and eosinophil concentration was significantly ($p{\leq}0.05$) higher in normal chicken in summer. The lipid peroxidation was higher in full feathered birds under summer stress. The enzyme glutathione reductase (GR) levels were significantly higher during the summer and varied significantly ($p{\leq}0.05$) between the normal and naked neck chicken in both seasons. The results indicated that the naked neck birds performed significantly better at high ambient temperatures with respect to growth, carcass and biochemical parameters. It was concluded that the ability of the naked neck chicken to adapt to high temperatures foresees a viable option for the biological mitigation of climate change.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.9
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• pp.1253-1260
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• 2017

Objective: Purpose was to determine the effects of grazing system and floor type on concentrations of blood metabolites, activity of creatine kinase, body weight and carcass characteristics of castrated Nguni goats. Methods: Forty eight, 7 month old goats were randomly allocated to herding and tethering treatments from 0800 to 1300 hours and accommodated on slatted and earth floors daily. Blood samples were collected by jugular venipuncture every fifteenth day for metabolite analysis. Slaughter was done at a commercial abattoir following 5 months of monitoring. Results: Tethered goats had significantly higher concentrations of urea (5.19 mmol/L) (p<0.001), creatinine ($55.87{\mu}mol/L$) (p<0.05), total protein (64.60 g/L) (p<0.01), and globulin (49.79 g/L) (p<0.001), whereas herded goats had higher glucose (3.38 mmol/L) (p<0.001), albumin (15.33 g/L) (p<0.05), albumin/globulin ratio (0.34) (p<0.01), and body weight (24.87 kg) (p<0.001). Slatted floors caused higher (p<0.01) albumin at 15.37 g/L. The interaction of grazing system and floor type affected creatinine, total protein, globulin at (p<0.01) and albumen/globulin ratio at (p<0.01). The least creatinine concentration and albumin/globulin ratio was in herded and tethered goats that were accommodated on earth floors, respectively. The highest total protein and globulin concentrations were in serum of tethered goats that were accommodated on earth floors. The highest (p<0.05) dressing percentage (45.26%) was in herded goats accommodated on slatted floors. Conclusion: Herding of goats lowered globulin concentration, improved estimated feed intake, blood glucose and albumin concentrations, albumin globulin ratio, increased body weights and weight related carcass characteristics. Floor type had very little effects on metabolites where earth floors only reduced albumin concentration. Tethering and housing goats on earth floors resulted in double stress that increased chronic infections.

• Steel and Composite Structures
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• v.7 no.4
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• pp.303-320
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• 2007

The objective of this study is to clarify the structural features of members consisting of connection, as a series of the previous study on the CFT column-to-beam tensile connection with combined cross diaphragm. This connection has the merits that the stress is distributed evenly on the beam flange and the diaphragm and the stress concentration is reduced, by improving the stress transfer route and restraining abrupt deformation of diaphragm. The finite element analysis was performed to find out the stress transfer through sleeve which is an important member of the connection with combined cross diaphragm. The length and thickness of sleeve were used as variables for the analysis. As the analysis results, the length and thickness of sleeve didn't influence on the capacity of the connection and played a role of a medium to transfer the stress from the diaphragm to the filled concrete. It is proposed that the appropriate length of sleeve be the same value as the diameter of sleeve and the appropriate ratio of sleeve diameter to sleeve thickness be 20. Two equations for evaluation of the load-carrying capacity of the connection were also proposed through the modification of the evaluation equation suggested in the previous study.

• Proceedings of the KSME Conference
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• 2001.06a
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• pp.752-757
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• 2001

To reduce stress concentration around the intersection between a spherical pressure vessel and a cylindrical nozzle under various load conditions using less material, the optimization for the distribution of reinforcement has researched. The ranked bidirectional evolutionary structural optimization(R-BESO) method is developed recently, which adds elements based on a rank, and the performance indicator which can estimate a fully stressed model. The R-BESO method can obtain the optimum design using less iteration number than iteration number of the BESO. In this paper, the optimized intersection shape is sought using R-BESO method for a flush and a protruding nozzle. The considered load cases are a radial compression, torque and shear force.