• Title/Summary/Keyword: AA2024

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Detection of Fatigue Damage in Aluminum Thin Plates with Rivet Holes by Acoustic Emission (리벳 구멍을 가진 알루미늄 박판구조의 피로손상 탐지를 위한 음향방출의 활용)

  • Kim, Jung-Chan;Kim, Sung-Jin;Kwon, Oh-Yang
    • Journal of the Korean Society for Nondestructive Testing
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    • v.23 no.3
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    • pp.246-253
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    • 2003
  • The initiation and growth of short fatigue cracks in the simulated aircraft structure with a series of rivet holes was detected by acoustic emission (AE). The location and the size of short tracks were determined by AE source location techniques and the measurement with traveling microscope. AE events increased intermittently with the initiation and growth of short cracks to form a stepwise increment curve of cumulative AE events. For the precise determination of AE source locations, a region-of-interest (ROI) was set around the rivet holes based on the plastic zone size in fracture mechanics. Since the signal-to-noise ratio (SNR) was very low at this early stage of fatigue cracks, the accuracy of source location was also enhanced by the wavelet transform do-noising. In practice, the majority of AE signals detected within the ROI appeared to be noise from various origins. The results showed that the effort of structural geometry and SNR should be closely taken into consideration for the accurate evaluation of fatigue damage in the structure.

Effect of pre-slaughter fasting time on carcass yield, blood parameters and meat quality in broilers

  • Xuezhuang Wu;Yahao Zhou;Zhentao Lu;Yunting Zhang;Tietao Zhang
    • Animal Bioscience
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    • v.37 no.2
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    • pp.315-322
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    • 2024
  • Objective: The aim of this study was to evaluate the effect of pre-slaughter fasting time on carcass yield, meat quality, blood parameters and glucose metabolism in broilers. Methods: Four hundred and fifty Arbor Acres (AA) broilers at 42 days of age were divided into 5 groups with 6 replicates in each group and 15 chickens as one replicate. Following this period, broilers from each group were distributed among five groups according to preslaughter fasting period as 4, 8, 12, 16, or 20 h. Results: With increasing fasting time, the carcass yield (p<0.01), the breast muscles yield (p<0.01) and the thigh yield (p<0.01) of the broilers were all linearly increased. With increasing fasting time, the L* values (p<0.01), cooking loss (p = 0.020), moisture content (p<0.01) in the leg muscles linearly downregulated, while the drip loss (p = 0.043), pH45 min (p<0.01) and pH24 h (p<0.01) were linearly upregulated. A trend for a lower (p = 0.071) shear force in the leg muscles was also observed in broilers fasted for longer time. Similar results were also found in breast muscles. The different fasting treatments did not influence the breast muscles glycogen content (p>0.10), while the increase of fasting time resulted in a linear decrease of the blood glucose (p = 0.021) and, more specifically, the glycogen content of the liver and leg muscles (p<0.001). With increasing fasting time, the aspartate transaminase (p<0.01), uric acid (p<0.01), and triglycerides (p<0.01) in serum linearly downregulated, while the alanine aminotransferase was linearly upregulated. Conclusion: The results of this study show a significant influence of fasting time on carcass yield and meat quality in broilers. Moderate fasting (8 to 12 h) before slaughter can reduce the weight loss of broilers. Prolonged fasting (≥16 h) increased body weight loss, decreased slaughtering performance and fluctuating blood indexes of broilers.

Roles of Inflammatory Biomarkers in Exhaled Breath Condensates in Respiratory Clinical Fields

  • Yong Jun Choi;Min Jae Lee;Min Kwang Byun;Sangho Park;Jimyung Park;Dongil Park;Sang-Hoon Kim;Youngsam Kim;Seong Yong Lim;Kwang Ha Yoo;Ki Suck Jung;Hye Jung Park
    • Tuberculosis and Respiratory Diseases
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    • v.87 no.1
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    • pp.65-79
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    • 2024
  • Background: Exhaled condensates contain inflammatory biomarkers; however, their roles in the clinical field have been under-investigated. Methods: We prospectively enrolled subjects admitted to pulmonology clinics. We collected exhaled breath condensates (EBC) and analysed the levels of six and 12 biomarkers using conventional and multiplex enzyme-linked immunosorbent assay, respectively. Results: Among the 123 subjects, healthy controls constituted the largest group (81 participants; 65.9%), followed by the preserved ratio impaired spirometry group (21 patients; 17.1%) and the chronic obstructive pulmonary disease (COPD) group (21 patients; 17.1%). In COPD patients, platelet derived growth factor-AA exhibited strong positive correlations with COPD assessment test (ρ=0.5926, p=0.0423) and COPD-specific version of St. George's Respiratory Questionnaire (SGRQ-C) score (total, ρ=0.6725, p=0.0166; activity, ρ=0.7176, p=0.0086; and impacts, ρ=0.6151, p=0.0333). Granzyme B showed strong positive correlations with SGRQ-C score (symptoms, ρ=0.6078, p=0.0360; and impacts, ρ=0.6007, p=0.0389). Interleukin 6 exhibited a strong positive correlation with SGRQ-C score (activity, ρ=0.4671, p=0.0378). The absolute serum eosinophil and basophil counts showed positive correlations with pro-collagen I alpha 1 (ρ=0.6735, p=0.0164 and ρ=0.6295, p=0.0283, respectively). In healthy subjects, forced expiratory volume in 1 second (FEV1)/forced vital capacity demonstrated significant correlation with CC chemokine ligand 3 (CCL3)/macrophage inflammatory protein 1 alpha (ρ=0.3897 and p=0.0068). FEV1 exhibited significant correlation with CCL11/eotaxin (ρ=0.4445 and p=0.0017). Conclusion: Inflammatory biomarkers in EBC might be useful to predict quality of life concerning respiratory symptoms and serologic markers. Further studies are needed.