• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.10a
• /
• pp.246-247
• /
• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.05a
• /
• pp.493-494
• /
• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2010.05a
• /
• pp.256-257
• /
• 2010

• Asian-Australasian Journal of Animal Sciences
• /
• v.10 no.4
• /
• pp.408-415
• /
• 1997

Data from 5,311 ewes and 13,076 lambing from 1977 through 1994 were used to analyse both annual and cumulative outputs in terms on total number of lambs born, total lamb weight weaned and total wool produced per ewe for ewe longevity 1 to 8 depending on their productive life in the flock. Ewes at Khushab produced 0.08 more lambs per parturition than ewes at Khizerabad; however, 0.39 less lambs were weaned at Khushab than at Khizerabad. Similarly, cumulative number of lambs born was more at Khushab flock than Khizerabad flock (p < .01). However, total weight of lambs weaned was greater at Khizerabad than Khushab flock (p < .01) for each ewe longevity. Most ewes (35%) were sold/replaced just after their first parturition (i. e. ewe longevity 1). The overall mean for annual sale/replacement was 32 and 23% at Khushab and Khizerabad, respectively. Distribution of growth and reproductive traits from 1977-94 did not show upward or downward trend inspite of heavy sale/replacement except yearly variation. Lack of any genetic progress over the year suggested that random breeding was employed without any scientific selection programme. Annual means for lambs born, lambs weaned and weight of lambs weaned per ewe present in the flock were the highest for ewe longevity 2 compared with other ewe longevity groups. Relative efficiency in terms of net income was highest for ewe longevity 5 followed by ewe longevity 4 and 6 in both flocks.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.12 no.2
• /
• pp.40-47
• /
• 2008

It is known that the adhesive interface testing of the rocket motor using the ultrasonic wave is superior to the other testing methods about the ability to economical detect the defects. But, the signal analysis of the ultrasonic wave takes a lot of time and efforts because the time interval of the transmitted pulse and the received pulse is too short to separate the reflected signals due to the multi-layers of the rocket motor. The ultrasonic testing of rocket motor have only applied to the automatic system about extremely limited areas like the debond in adhesive interface between the motor case and the insulator. In this study the new technique to detect the debond between the liner and the propellant using the property of the resonance and the lamb waves instead of the existing ultrasonic testing was described.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.19 no.5
• /
• pp.340-346
• /
• 1999

Minimum reflection and backward radiation methods on liquid/solid interrace were used to determine the velocity dispersion relation of acoustical surface wave for brass and aluminum substrates and copper/stainless steel nickel/brass, and nickel/aluminum layered substrates. Dispersion data agreed to dispersion characteristics of a generalized Lamb wave. The difference between velocities determined by two phenomena was closely related to the dispersion characteristics. This correspondence was explained by considering the generation mechanism of surface waves and the concept of group velocity.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.33 no.3
• /
• pp.264-269
• /
• 2013

Since MFC(macro-fiber composite) transducer has been developed, many researchers have tried to apply this transducer on SHM(structural health monitoring), because it is so flexible and durable that it can be easily embedded to various kinds of structures. The objective of this paper is to figure out the benefits and feasibility of applying MFC transducers to guided wave technique. For this, we have experimentally tested the performance of MFC patches as transmitter and sensors for excitation and reception of guided waves on the thin aluminum alloy plate. In order to enhance the signal accuracy, we applied the FIR filter for noise reduction as well as used STFT(short-time Fourier transform) algorithm to image the guided wave characteristics clearly. From the results, the guided wave generated based on MFC showed good agreement with its theoretical dispersion curves. Moreover, the ultrasonic Lamb wave techniques based on MFC patches in pitch-catch manner was tested for detection of surface notch defects of which depths are 10%, 20%, 30% and 40% of the aluminum plate thickness. Results showed that the notch was detectable well when the notch depth was 10% of the thickness or greater.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.55-59
• /
• 2007

It is known that the adhesive interface testing of the rocket motor which using the ultrasonic wave iS superior to the other testing methods about the economically detectable abiliη of the defects. But, the signal analysis of the ultrasonic wave takes too much time and effort that the time interval of the transmitted pulse and the received pulse is too short to be separated the reflected signals because the structure of the rocket motor is multi-layers. The ultrasonic testing of rocket motor have been only applied with automatic system about extremely limited area like the debond in adhesive interface between the motor case and insulator. In this study the new technique to detect the debond between the liner and the propellant using the property of the resonance and Lamb waves was described as comparing the existence ultrasonic testing.

• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.1
• /
• pp.79-86
• /
• 1993

Twelve docked and 12 intact Najdi lambs of equal numbers of males and females were slaughtered at 40 kg shorn shrunk body weight, Lipid in all empty body fat components; namely, subcutaneous, intermuscular, intramuscular, omental, mesenteric, channel, perirenal, pericardial, tail, viscera, bone and hide, were determined. Except for ram lambs, which had a lower percentage of lipid in intermuscular partition in loin cut, sex did not influence the relative proportion of subcutaneous or intermuscular fat in each wholesale cut. The data also showed that docking did not change the distribution of lipid in intermuscular and intramuscular fat partitions in each wholesale cut. Docked lambs tended to accumulate lower proportions of the lipid in subcutaneous fat component in the cuts located along the dorsal line than intact lambs. The total amount of lipid deposited in the empty body of ewe lamb was heavier in weight than that of ram lamb. Docking had no effect on the distribution of total lipid in the empty body, except for subcutaneous fat component, being greater in docked lambs than did intact ones. Generally, the highest proportion of fat was associated with subcutaneous depot followed, in order, by intermuscular, mesenteric, tail, intramuscular and omental fat partitions.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.6
• /
• pp.828-833
• /
• 2002

Thirty mature pregnant ewes of the Phan Rang breed with an initial live weight of 30 to 45 kg were used to compare the effects of three different diets in late pregnancy on ewe and lamb performance. All diets contained 20% of whole sugar cane, 16% rice bran, 26% cassava root and 6% molasses urea block. The remaining 32% of dry matter consisted of Jackfruit (JF diet), 16% each of Jackfruit and Cassava foliage (JF+CS diet) or Jackfruit and Flemingia foliage (JF+FM diet). The diets were fed at 3.5% of actual BW of the individual animal. The foliages were offered at 120% of the amount decided in the diets of the requirements. The JF+CS diet resulted in significantly higher feed intake than the JF diet, and also a higher feed intake than the JF+FM diet, but this difference was not significant. The ewe weight changes during the last 8 weeks of pregnancy, or from start to 24 h after lambing, were significantly different. The highest weight gain was obtained from the ewes fed the JF+CS diet. Diets had no effect on weight changes of ewes during 3 weeks after lambing but a significant effect on the litter birth weight, with the JF+CS diet giving the highest litter birth weight. There was, however, no effect on the litter weight at 21 days or litter growth rate from birth to 21 days due to the experimental diets.