• Title/Summary/Keyword: Bursa

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Geometrically nonlinear analysis of functionally graded porous beams

  • Akbas, Seref D.
    • Wind and Structures
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    • v.27 no.1
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    • pp.59-70
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    • 2018
  • In this paper, geometrically non-linear analysis of a functionally graded simple supported beam is investigated with porosity effect. The material properties of the beam are assumed to vary though height direction according to a prescribed power-law distributions with different porosity models. In the nonlinear kinematic model of the beam, the total Lagrangian approach is used within Timoshenko beam theory. In the solution of the nonlinear problem, the finite element method is used in conjunction with the Newton-Raphson method. In the study, the effects of material distribution such as power-law exponents, porosity coefficients, nonlinear effects on the static behavior of functionally graded beams are examined and discussed with porosity effects. The difference between the geometrically linear and nonlinear analysis of functionally graded porous beam is investigated in detail. Also, the effects of the different porosity models on the functionally graded beams are investigated both linear and nonlinear cases.

An investigation of non-linear optimization methods on composite structures under vibration and buckling loads

  • Akbulut, Mustafa;Sarac, Abdulhamit;Ertas, Ahmet H.
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.209-231
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    • 2020
  • In order to evaluate the performance of three heuristic optimization algorithms, namely, simulated annealing (SA), genetic algorithm (GA) and particle swarm optimization (PSO) for optimal stacking sequence of laminated composite plates with respect to critical buckling load and non-dimensional natural frequencies, a multi-objective optimization procedure is developed using the weighted summation method. Classical lamination theory and first order shear deformation theory are employed for critical buckling load and natural frequency computations respectively. The analytical critical buckling load and finite element calculation schemes for natural frequencies are validated through the results obtained from literature. The comparative study takes into consideration solution and computational time parameters of the three algorithms in the statistical evaluation scheme. The results indicate that particle swarm optimization (PSO) considerably outperforms the remaining two methods for the special problem considered in the study.

Comparison of Milk Yield and Animal Health in Turkish Farms with Differing Stall Types and Resting Surfaces

  • Kara, Nurcan Karslioglu;Galic, Askin;Koyuncu, Mehmet
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.2
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    • pp.268-272
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    • 2015
  • The current study was carried out to determine the influence of different resting surfaces and stall types on milk yield and animal health. Study was carried out in Bursa that is one of the most important cities of Turkey in terms of dairy production. Effects of resting surfaces and stall types on milk yield were found to be important. Also influence of different resting surfaces and stall types on lactation length was examined and found that rubber mats were different from the two other options. Relationships between different resting surfaces or stall types and health problems were examined and connection between stall type and repeat breeding (RB), dystocia, retained placenta and a connection between resting surface types and RB and clinical mastitis were found to be important. Considering their economic reflections, it can be said that results are quite important to the Turkish dairy industry.

Prevalence of Cryptosporidium baileyi Infection of Chickens In South Kyeonggi Area (경기남부지역의 닭에 있어서 Cryptosporidium baileyi의 감염상황)

  • 서영석;박찬숙;김창수
    • Korean Journal of Veterinary Service
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    • v.18 no.2
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    • pp.152-157
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    • 1995
  • A total of 1050 layer and broiler chickens from 63 flocks of 21 poultry farms in South-Kyeonggi area, aged from 1 to 18 weeks, were investigated for the prevalence of Cryptosporidium baileyi infection from May 1992 to March 1993. The results have shown that 44 chickens(4.19%) were infected with C.(baileyi during the period of investigation) Fecal samples were treated by using Sheather's flotating technique and were examined under the light and phase contrast microscopy and then stained by Kinyoun method. Cryptosporidium oocysts were found in 35 out of 650 broilers(5.4%) and 9 out of 400 layer chickens(2.3%) aged mainly from 2 to 12 weeks. The regional infection rate were 4.7% in Pyeong-taek, 5.1% in An-sung and 2.3% in Yong-in, respectively. The average size of isolated oocyst was about $5.23{\times}4.92{\mu}m$ and the oocysts were orally inoculated into 2-day-old SPF chickens for the histological examination of oocyst in bursa of Fabricius. The study has concluded that C. baileyi infects chickens and oocysts were isolated in South-Kyeonggi area.

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Light and Scanning Electron Microscope Observatt-ons on Sexual Dimorphism in Pupa of Mullberry silkworm, bombyx Mori Linn (Lopidoptera : Bombycidae)

  • Kumar, Vineet;Tewari, S.K.;Awasthi, A.K.;Datta, R.K.
    • Journal of Sericultural and Entomological Science
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    • v.41 no.2
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    • pp.87-93
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    • 1999
  • Under Light and Scanning electron microscope, the pupal morphology of mulberry silkworm Bombyx mori Linn. revealed the prothorax and metathorax, well developed mesothorax, less defined last pair of sporacle, well exposed prothoracic femora and wing pads approaching the anterior margin of Ab III. The important sex separating characters viz, wegiht, antennal elevations, intersegmental lines and genings have discussed. Further, two separate openings bursa copulatrix and ovipositional opening were observed, performing different functions in abult moth.

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Variations in the hysteretic behavior of LRBs as a function of applied loading

  • Ozdemir, Gokhan;Bayhan, Beyhan;Gulkan, Polat
    • Structural Engineering and Mechanics
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    • v.67 no.1
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    • pp.69-78
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    • 2018
  • The study presented herein focused on the change in hysteretic force-deformation behavior of lead rubber bearings (LRBs). The material model used to idealize response of LRBs under cyclic motion is capable of representing the gradual attrition in strength of isolator unit on account of lead core heating. To identify the effect of loading history on the hysteretic response of LRBs, a typical isolator unit is subjected to cyclic motions with different velocity, amplitude and number of cycles. Furthermore, performance of an LRB isolated single degree of freedom system is studied under different seismic input levels. Finally, the significance of lead core heating effect on LRBs is discussed by considering the current design approach for base isolated structures. Results of this study show that the response of an LRB is governed strongly by the amplitude and number of cycles of the motion and the considered seismicity level.

Post-buckling responses of a laminated composite beam

  • Akbas, Seref D.
    • Steel and Composite Structures
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    • v.26 no.6
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    • pp.733-743
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    • 2018
  • This paper presents post-buckling responses of a simply supported laminated composite beam subjected to a non-follower axially compression loads. In the nonlinear kinematic model of the laminated beam, total Lagrangian approach is used in conjunction with the Timoshenko beam theory. In the solution of the nonlinear problem, incremental displacement-based finite element method is used with Newton-Raphson iteration method. There is no restriction on the magnitudes of deflections and rotations in contradistinction to von-Karman strain displacement relations of the beam. The distinctive feature of this study is post-buckling analysis of Timoshenko Laminated beams full geometric non-linearity and by using finite element method. The effects of the fibber orientation angles and the stacking sequence of laminates on the post-buckling deflections, configurations and stresses of the composite laminated beam are illustrated and discussed in the numerical results. Numerical results show that the above-mentioned effects play a very important role on the post-buckling responses of the laminated composite beams.

Mixed infection with coccidiosis, fowl typhoid and infectious bursal disease in broiler, a case report (육계에서 콕시듐증, 가금티푸스 및 전염성 F낭병 혼합감염 발생 예)

  • 김윤태;고원석;이정원;서이원;양홍지;송희종;오언평
    • Korean Journal of Veterinary Service
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    • v.22 no.1
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    • pp.53-59
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    • 1999
  • In a flocks of broiler, 29 days old, was submitted to Iksan-branch, Livestock Development and Research Institute of Chonbuk province. Grossly, their feathers were ruffled and multiful hemorrhage were presented in the thigh and pectoral muscles. There were multifocal foci on the liver surface and enlarged and edematous on bursa of Fabricius. The coagulative materials, which were blood-tinged, were filled in cecum, and Eimeria oocysts were detected in the cecal contents. Microscopically, macrogametes were noted in the cecum, degeneration and necrosis of lymphocytes in the medullary area of bursal follicles, and multifocal necrosis of hepatocytes. There were positive in the infectious bursal disease(IBD) through selologic test and Salmonella gallinarum were detected. This report is a mixed infection case of coccidium, IBD and fowl typhoid in a flocks of broiler.

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Uncinaria infection in a Badger, A case report (오소리에서 Uncinaria의 감염 증례)

  • 서이원;양홍지;임채웅
    • Korean Journal of Veterinary Service
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    • v.21 no.4
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    • pp.401-405
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    • 1998
  • A male badger which showed depression and bloody diarrhea was submitted to Iksan Branch of Chonbuk Veterinary Service Laboratory for necropsy on May 1998. Grossly, paleness of the mucous membranes was observed and the small intestinal contents were hamorrhagic. The numerous tiny hookworms, sized in 5-10 mm and greyish-white in color, attached to the intestinal mucosa. Male bursa was well developed. Histologically, intestinal lumen was filled with hemorrhagic contents, which contained worms. The epithelial cells of the villi were underwent degeneration and lamina propria was infiltrated by lymphocytes and plasma cells, and goblet cells were hyperplastic. There were rounded cutting plates in the funnel-shaped buccal capsule and transverse striation on sheath in hookworm, ultrastructurally, which were consistent with Uncinaria sp. The shape of eggs were ellipsoidal and morula, and some eggs contained a mobile larva. It was concluded that this badger was infected with Uncinaria.

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Studies on Histological Changes of Bursa of Fabricius in Chicken Treated with Thyroxine II. Effect of Thyroxine on Antibody Production (갑상선(甲狀腺) 호르몬이 닭의 Fabricius낭(囊)에 미치는 조직학적변화(組織學的變化)에 관(關)한 연구(硏究) II. 갑상선(甲狀腺) 호르몬이 항체산생(抗體産生)에 미치는 영향(影響))

  • Kim, Soon Bok;Lee, Cha Soo
    • Korean Journal of Veterinary Research
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    • v.20 no.2
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    • pp.99-104
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    • 1980
  • The effects of thyroxine (TX) or propylthiouracil (PPT) administration on the antibody forming activity agains t sheep red blood cell (SRBC) and Newcastle disease virus (NDV) were studied by using of hemagglutination and hemagglutination-inhibition techniques. Antibody titers to both SRBC and NDV increased significantly in the TX-treated group, whereas decreased in the PPT-treated group, compared with control. When TX was administered after antigen inoculatioon, antibody forming activity was significantly enhanced, compared with the TX administration before antigen inoculation.

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