• Title/Summary/Keyword: ultrasonic property

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A Study on the Performance of EFI Engine Used Ultrasonic Energy Adding Fuel System(I) -Attaching Importance to Fuel Characteristics for Ultrasonic- (초음파연료공급장치를 이용한 EFI 기관의 성능에 관한 연구(I) -초음파에 의한 연료의 물성변화를 중심으로-)

  • 윤면근;류정인
    • Transactions of the Korean Society of Automotive Engineers
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    • v.5 no.2
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    • pp.42-49
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    • 1997
  • This experimental study was performed to find fuel property variations of the ultrasonic energy adding gasoline and improve the spray characteristics of the multipoint injector for EFI engine. The cause and effect of the characteristic improvement of the ultrasonic energy adding fuel was found out by the chemical structure analysis (NMR, IR), distillation and viscosity test. The results are obtained that the chemical property of gasoline organizition was changed aromatics to paraffins and branch index as the physical characteristics of gasoline were improved by ultrasonic energy. There were higher distillation and lower viscosity in ultrasonic energy adding gasoline.

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Study on Magnetic Property Enhancement of Metal Powders for Magnetic Tape by Using Ultrasonic Dispersion (자기테이프용 Metal Powder의 초음파 분산에 의한 자기적 특성 향상에 관한 연구)

  • Kim, Chang-Gon;Choe, Hyeon-Seung;Jang, Hak-Jin;Yun, Seok-Yeong;Kim, Tae-Ok
    • Korean Journal of Materials Research
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    • v.11 no.11
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    • pp.972-977
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    • 2001
  • It was investigated the effect of ultrasonic treatment on magnetic property of ultra fine magnetic Fe powders ($\alpha$-Fe) for magnetic tape. The properties were characterized with vibrating sample magnetometer (VSM), particle size analyzer (PSA) and scanning electron microscope (SEM). At 4hours ultrasonic treatment of 70 kHz, magnetic properties such as squareness ratio (S.Q. : 0.8868), orientation ratio (O.R. : 2.45) and switching field distribution (S.F. D. : 0.394) before taping were relatively enhanced. Cumulative particle size distribution of less than 5$\mu\textrm{m}$ fine powder was above 90% below 1 hour leaving time after ultrasonic treatment and it was supposed that ultrasonic treatment prevent aggregation. The magnetic values of S.Q. and S.F.D. of tape manufactured at 70 kHz and 4hour ultrasonic treatment were improved from 0.7747, 0.3818 to 0.8037, 0.3706, respectively. Electro-magnetic property used as in-output signal characteristic was improved, which showed that ultrasonic treatment developed the magnetic properties.

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Evaluation of Elastic Properties for Nanoscale Coating Layers Using Ultrasonic Atomic Force Microscopy (초음파원자현미경을 이용한 나노스케일 박막 코팅층에 대한 탄성특성 평가)

  • Kwak, Dong Ryul;Cho, Seung Bum;Park, Ik Keun
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.5
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    • pp.475-480
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    • 2015
  • Ultrasonic atomic force microscopy (Ultrasonic-AFM) has been used to investigate the elastic property of the ultra-thin coating layer in a thin-film system. The modified Hertzian theory was applied to predict the contact resonance frequency through accurate theoretical analysis of the dynamic characteristics of the cantilever. We coat 200 nm thick Aluminum and Titanium thin films on the substrate using the DC Magnetron sputtering method. The amplitude and phase of the contact resonance frequency of a vibrating cantilever varies in response to the local stiffness constant. Ultrasonic-AFM images were obtained using the variations in the elastic property of the materials. The morphology of the surface was clearly observed in the Ultrasonic-AFM images, but was barely visible in the topography. This research demonstrates that Ultrasonic-AFM is a promising technique for visualizing the distribution of local stiffness in the nano-scale thin coatings.

A Property of Porous Concrete applied by Recycled Cement and using Recycled Aggregates Made of EPS Waste (재생시멘트와 폐 EPS 재생골재를 사용한 포러스 콘크리트 물성)

  • Kim Sung-Su;Park Cha-Won;Ahn Jae-Cheol;Kang Byeung-Hee
    • Proceedings of the Korean Institute of Building Construction Conference
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    • v.y2004m10
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    • pp.59-63
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    • 2004
  • In recent days. it is necessary to find environment-friendly way of diposing industrial waste and reclying system. So this study will analyze the property of Porous concrete improved by concrete waste powder and recycled lightweight aggregate and then suggest the ways of reclying. The method deals with experimenting unit weight of capacity. thermal conductivity, compression and ultrasonic pluse velocity. Considering the relation between ultrasonic pluse velocity and unit weight & thermal conductivity through the graph. the result of relation between ultrasonic pluse velocity and unit weight & thermal conductivity on the graph expessed their high interaction shown as direct proportion on the graph. Recycled Porous concrete merits lightweight and adiabatic. Therefore. we will expect that the current using ALC and Recycled Porous concrete has be similar thermal conductivity.

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A Study on Ultrasonic Evaluation of Material Defects in Carbon/carbon Composites

  • Im, Kwang-Hee;David K. Hsu;Cha, Cheon-Seok;Sim, Jae-Ki;Yang, In-Young
    • Journal of Mechanical Science and Technology
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    • v.16 no.12
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    • pp.1652-1663
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    • 2002
  • It is desirable to perform nondestructive evaluation to assess material properties and part homogeneity because manufacturing of carbon/carbon (C/C) composites requires complicated and costly processes. In this work several ultrasonic techniques were applied to carbon/carbon composites for the evaluation of spatial variations in material properties that are attributable to the manufacturing process. In a large carbon/carbon composite manufactured by chemical vapor infiltration (CVI) method, the spatial variation of ultrasonic velocity was measured and found to be consistent with the densification behavior in CVI process in order to increase the density of C/C composites. Ultrasonic velocity and attenuation depend on a density variation of materials. Low frequency through-transmission scans based on both amplitude and time-of-flight of the ultrasonic pulse were used for mapping out the material property inhomogeneity These results were compared with that obtained by dry-coupling ultrasonics. Pulse-echo C-scans was used to image near-surface material property anomalies such as the placement of spacers between disks during CVI. Also, optical micrograph had been examined on the surface of C/C composites using a destructive way.

Partial Discharge Ultrasonic Analysis for Generator Stator Windings

  • Yang, Yong-Ming;Chen, Xue-Jun
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.670-676
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    • 2014
  • The objective of this research is to utilize the ultrasonic method to analyze the property of partial discharge (PD) which is generated by the winding of the insulation stator in the generator. Therefore, a PD measurement system is built based on ultrasonic and virtual instruments. Three types of PD models (internal PD model, surface PD model and slot PD model) have been constructed. With the analysis of these experimental results, this research has identified the ultrasonic signals of the discharges which were produced by three types of PD models. This analysis shows the different features among these PD types. Both the time domain and frequency domain of the ultrasonic signals are obviously different. In addition, an experiment based on a large rotating machine has been done to analyze ultrasonic noises. The result indicates that the ultrasonic noises can be wiped off by the filters and algorithms. The application of this system is convenient for the detection of early signs of insulation failure, which is an effective method for diagnosis of insulation faults.

The Effect of Graphite Morphology on the Propagation of Ultrasonic Wave in Ductile Cast Iron (구상흑연주철에서 초음파 전파속도에 미치는 흑연형상의 영향)

  • Lee, Kye-Wan;Yang, No-Seok;Park, Un-Su
    • Journal of Korea Foundry Society
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    • v.9 no.3
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    • pp.228-236
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    • 1989
  • The relationships between nodularity, tensile property and ultrasonic velocity were studied in ductile iron castings having similar matrix structure. Also, the effects of heat treatment and the number of graphite nodules on the ultrasonic velocity were investigated. The results were as follows 1. The ultrasonic velocity increased proportionally with increassing nodularity and tensile strength. 2. The ultrasonic velocity in annealed and normalized state decreased average 1.7% and 3.4% respectively than that in as cast state. 3. The ultrasonic velocity increased with increasing the number of graphite nodules. Therefore, ductile iron castings can be evaluated in the only case of castings having the same manufacturing history by ultrasonic velocity.

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An anisotropic ultrasonic transducer for Lamb wave applications

  • Zhou, Wensong;Li, Hui;Yuan, Fuh-Gwo
    • Smart Structures and Systems
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    • v.17 no.6
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    • pp.1055-1065
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    • 2016
  • An anisotropic ultrasonic transducer is proposed for Lamb wave applications, such as passive damage or impact localization based on ultrasonic guided wave theory. This transducer is made from a PMNPT single crystal, and has different piezoelectric coefficients $d_{31}$ and $d_{32}$, which are the same for the conventional piezoelectric materials, such as Lead zirconate titanate (PZT). Different piezoelectric coefficients result in directionality of guided wave generated by this transducer, in other words, it is an anisotropic ultrasonic transducer. And thus, it has different sensitivity in comparison with conventional ultrasonic transducer. The anisotropic one can provide more information related to the direction when it is used as sensors. This paper first shows its detailed properties, including analytical formulae and finite elements simulations. Then, its application is described.

Mechanical Properties and Ultrasonic Parameters of the Apple Flesh while in Storage (저장기간에 따른 사과 과육의 기계적 특성 및 초음파 파라미터)

  • 김기복;김만수;정현모;이상대
    • Journal of Biosystems Engineering
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    • v.28 no.3
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    • pp.239-244
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    • 2003
  • The potential use of ultrasonic technique for firmness measurement of apples was evaluated. Mechanical properties(bioyield deformation, bioyield strength, rupture deformation, ultimate strength, and elastic modulus) and ultrasonic parameters (ultrasonic velocity, attenuation coefficient and the first peak frequency) of the apple flesh during the storage time were measured and analyzed. Ultrasonic parameters were determined from the measurement of ultrasonic wave transmission through the apple flesh specimen. Mechanical properties were obtained by universal testing machine. The bioyield strength, rupture strength, elastic modulus, ultrasonic velocity, and the first peak frequency of the apple flesh decreased with the storage time. The bioyield deformation, rupture deformation, and ultrasonic attenuation coefficient increased with the storage time. The correlation analysis between ultrasonic parameters and mechanical properties and the storage time was performed. The high correlations were found between the storage time and the ultrasonic parameters, and these relationships seem to be useful for determining the firmness of the apple flesh.

Effect of Ultrasonic Treatment on Physicochemical Properties and Palatability of Cooked Chicken Meat (초음파 처리가 가열 계육의 이화학적 성질 및 기호성에 미치는 영향)

  • 박충균;박성하;전덕수;김현대;문윤희;정인철
    • Food Science of Animal Resources
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    • v.21 no.2
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    • pp.126-132
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    • 2001
  • This study was carried out to investigate the effect of ultrasonic treatment on physicochemical and sensory properties of cooked chicken meat. Moisture content of ultrasonic treated breast meat was higher than that of control, fat content of control of breast and leg meat were higher than that of ultrasonic treatment, and protein of control of breast meat was higher than that of ultrasonic treatment. Hunters L(lightness)-and a(redness)-value were not different between cooking methods, L-value of breast meat and a-value of leg meat were higher without regard to cooking method. Hunterb (yellowness)-value was not different among cooking chicken meats. Cooking yield was not different between cooking methods, pH of ultrasonic treated chicken meats were higher than that of control. Water holding capacity and salt soluble protein extractability of ultrasonic treated breast meat were greater than that of control. Water soluble protein extractability of ultrasonic treated leg meat was higher than that of control, and shear force value was not different between cooking methods. Hardness, cohesiveness and gumminess were not different between cooking methods and parts of muscle. Springiness of ultrasonic treated leg meat was greater than that of control and chewiness of breast meat was higher than that of leg meat. Aroma, texture, juiciness and overall acceptability were not different between cooking methods, taste of ultrasonic treated leg meat was higher than that of control. In addition, the sensory scores of parts of muscle were affected greater than that of cooking methods.

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