The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform

Qingjie Guo - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of pressure fluctuation signals in an acoustic bubbling fluidized bed
    Journal of the Taiwan Institute of Chemical Engineers, 2011
    Co-Authors: Jing Zhou, Qingjie Guo
    Abstract:

    Abstract The pressure fluctuation of the fluid catalytic cracking (FCC) particles was described using a pressure transducer probe in an acoustic bubbling fluidized bed. The effect of Sound Frequency and Sound pressure level on the pressure fluctuation was researched in this work. The results showed that the minimum fluidization velocity has a minimum value when the Frequency of Sound waves was 150 Hz, and decreased as the Sound pressure level was increased at the same Sound Frequency. On the basis of discrete wavelet transform, an original signal was resolved into six detailed scale signals. It was found that the scalograms obtained by wavelet transform provide both the localization of scale and time, and make it possible to identify the status of the bed such as the passage of bubbles. The results indicated that the dominant Frequency decreased with increasing Sound Frequency from 50 to 150 Hz, and further increased with increasing Sound Frequency from 150 to 500 Hz. The dominant Frequency has a minimum value at a Sound Frequency of 150 Hz.

  • Agglomerate size in an acoustic fluidized bed with Sound assistance
    Chemical Engineering and Processing: Process Intensification, 2007
    Co-Authors: Qingjie Guo, Wenzhong Shen, Xiangping Yang, Huie Liu
    Abstract:

    Three types of SiO2 ultrafine particles were used to investigate the fluidization behavior in a fluidized bed with Sound excitation. It has been shown that agglomerate size tends to reduce with an increase in Sound pressure level. At a given Sound pressure level, there exists a critical Sound Frequency (fc). Agglomerate size is decreased with increasing Sound Frequency as Sound Frequency less than fc. Whereas, agglomerate size intends to grow with an increase in Sound Frequency as Sound Frequency exceeds fc. A mathematic model to predict the agglomerate size has been developed based on energy balance between the agglomerate collision energy, the energy arising from Sound wave, and cohesive energy. The model can predict qualitatively the effects of Sound Frequency and Sound pressure level on agglomerate size.

  • influence of Sound wave characteristics on fluidization behaviors of ultrafine particles
    Chemical Engineering Journal, 2006
    Co-Authors: Qingjie Guo, Huie Liu, Wenzhong Shen, Xianghong Yan, Rugao Jia
    Abstract:

    Abstract The fluidization behaviors of ultrafine particles were investigated in an acoustic fluidized bed with one type of micron particles and two types of nanoparticles. With the assistance of Sound wave having low Sound Frequency and high Sound pressure level, the micron and nanoparticles can be fluidized smoothly with fluidization behaviors similar to those of Geldart Group A particles. It has been found that increasing Sound Frequency leads to a reduction in minimum fluidization velocity, and then to an increase in minimum fluidization velocity. At the same Sound Frequency, the fluidization quality of nanoparticles improves significantly with increasing Sound pressure level (100–103.4 dB). In addition, a thorough investigation indicates that Sound wave configuration have an influence on fluidization process of ultarfine particles. Experiments show that both Sine wave and Triangle wave can enhance fluidization quality of ultarfine particles.

  • Fluidization of Ultrafine Particles in a Bubbling Fluidized Bed with Sound Assistance
    Chemical Engineering & Technology, 2005
    Co-Authors: Qingjie Guo, Minghua Wang, Chaohe Yang
    Abstract:

    The fluidization behaviors of various nanometer and micron particles, including SiO 2 , TiO 2 , and cornstarch particles with primary particle sizes of 5 nm-10.69 μm, were investigated in a fluidized bed with inside diameter 56 mm under different Sound pressure levels and Sound frequencies. It has been demonstrated that the relatively uniform ultrafine particle agglomerates reach homogeneous fluidization with Sound assistance at low Sound frequencies due to the Sound field disrupting large size agglomerates. Furthermore, slugging and channeling of the bed was eliminated, accompanied by negligible elutriation. For each of the nanometer and micron particles examined, the minimum fluidization velocity decreased with increasing Sound Frequency, and then increased with Sound Frequency at a given Sound pressure level. There is a minimum value in the curve of minimum fluidization velocity versus Sound Frequency, the critical Sound Frequency, at which the bed fluidized smoothly. Varying the Sound pressure level can significantly improve the fluidization quality of the bed.

Huie Liu - One of the best experts on this subject based on the ideXlab platform.

  • Agglomerate size in an acoustic fluidized bed with Sound assistance
    Chemical Engineering and Processing: Process Intensification, 2007
    Co-Authors: Qingjie Guo, Wenzhong Shen, Xiangping Yang, Huie Liu
    Abstract:

    Three types of SiO2 ultrafine particles were used to investigate the fluidization behavior in a fluidized bed with Sound excitation. It has been shown that agglomerate size tends to reduce with an increase in Sound pressure level. At a given Sound pressure level, there exists a critical Sound Frequency (fc). Agglomerate size is decreased with increasing Sound Frequency as Sound Frequency less than fc. Whereas, agglomerate size intends to grow with an increase in Sound Frequency as Sound Frequency exceeds fc. A mathematic model to predict the agglomerate size has been developed based on energy balance between the agglomerate collision energy, the energy arising from Sound wave, and cohesive energy. The model can predict qualitatively the effects of Sound Frequency and Sound pressure level on agglomerate size.

  • influence of Sound wave characteristics on fluidization behaviors of ultrafine particles
    Chemical Engineering Journal, 2006
    Co-Authors: Qingjie Guo, Huie Liu, Wenzhong Shen, Xianghong Yan, Rugao Jia
    Abstract:

    Abstract The fluidization behaviors of ultrafine particles were investigated in an acoustic fluidized bed with one type of micron particles and two types of nanoparticles. With the assistance of Sound wave having low Sound Frequency and high Sound pressure level, the micron and nanoparticles can be fluidized smoothly with fluidization behaviors similar to those of Geldart Group A particles. It has been found that increasing Sound Frequency leads to a reduction in minimum fluidization velocity, and then to an increase in minimum fluidization velocity. At the same Sound Frequency, the fluidization quality of nanoparticles improves significantly with increasing Sound pressure level (100–103.4 dB). In addition, a thorough investigation indicates that Sound wave configuration have an influence on fluidization process of ultarfine particles. Experiments show that both Sine wave and Triangle wave can enhance fluidization quality of ultarfine particles.

Chaohe Yang - One of the best experts on this subject based on the ideXlab platform.

  • Fluidization of Ultrafine Particles in a Bubbling Fluidized Bed with Sound Assistance
    Chemical Engineering & Technology, 2005
    Co-Authors: Qingjie Guo, Minghua Wang, Chaohe Yang
    Abstract:

    The fluidization behaviors of various nanometer and micron particles, including SiO 2 , TiO 2 , and cornstarch particles with primary particle sizes of 5 nm-10.69 μm, were investigated in a fluidized bed with inside diameter 56 mm under different Sound pressure levels and Sound frequencies. It has been demonstrated that the relatively uniform ultrafine particle agglomerates reach homogeneous fluidization with Sound assistance at low Sound frequencies due to the Sound field disrupting large size agglomerates. Furthermore, slugging and channeling of the bed was eliminated, accompanied by negligible elutriation. For each of the nanometer and micron particles examined, the minimum fluidization velocity decreased with increasing Sound Frequency, and then increased with Sound Frequency at a given Sound pressure level. There is a minimum value in the curve of minimum fluidization velocity versus Sound Frequency, the critical Sound Frequency, at which the bed fluidized smoothly. Varying the Sound pressure level can significantly improve the fluidization quality of the bed.

A. E. Camilleri - One of the best experts on this subject based on the ideXlab platform.

  • Sound Frequency analysis and the site of snoring in natural and induced sleep
    Clinical Otolaryngology, 2002
    Co-Authors: S Agrawal, Kevin Mcguinness, P. Stone, J. Morris, A. E. Camilleri
    Abstract:

    The aim of this study was to compare the snoring Sounds induced during sleep nasendoscopy, and to compare them with those of natural sleep using Sound Frequency spectra. The snoring of 16 subjects was digitally recorded during natural and induced sleep, noting the site of vibration during sleep nasendoscopy. Patients with palatal snoring during sleep nasendoscopy had a median peak Frequency at 137 Hz (118 snore samples). The peak Frequency of tongue-base snoring was 1243 Hz (10 snore samples), and simultaneous palate and tongue was 190 Hz (six snore samples). The median power ratios were 7, 0.2 and 5 respectively. The centre frequencies were 371, 1094 and 404 Hz respectively. Epiglottic snores had a peak Frequency of 490 Hz (five snore samples). Comparison of the induced (n = 118) and natural (n = 300) snore samples of the 12 palatal snorers showed a significant difference in both the power ratio and centre frequencies (P = 0.031 and P = 0.049). The peak Frequency position was similar (P = 0.34). Our results indicate that induced snores contain a higher Frequency component of Sound, not evident during natural snoring. This is consistent with an element of tongue-base snoring. Although there is good correlation generally, sleep nasendoscopy may not accurately reflect natural snoring.

Rina Sakai - One of the best experts on this subject based on the ideXlab platform.

  • Usefulness of Hammering Sound Frequency Analysis as an Evaluation Method for the Prevention of Trouble during Hip Replacement
    Journal of Biomedical Science and Engineering, 2020
    Co-Authors: Rina Sakai, Katsufumi Uchiyama, Naonobu Takahira, Kazuhiro Yoshida, M. Kakeshita, Y. Otsu, Masanobu Ujihira
    Abstract:

    In total hip arthroplasty, judgment of the appropriateness of stem hammering is dependent on the experience and feelings of the surgeon and no objective evaluation method has been established. In this study, a Frequency analysis of the hammering Sounds in total hip arthroplasty was performed to investigate objective judgment criteria capable of preventing problems during surgery. Stem hammering was applied following the surgeon’s feelings as usual in an operating room. A directional microphone was placed at a distance about 2 m from the surgical field and the peak Frequency reaching the maximum amplitude was determined by Fourier analysis. It was clarified that the same peak Frequency repeats when appropriate fixation is acquired during surgery, suggesting that intraoperative fracture and postoperative loosening can be prevented by stopping hammering at the time the peak Frequency converged. Investigation of changes in the hammering Sound Frequency may serve as objective judgment criteria capable of preventing problems during surgery.

  • Prediction of Intraoperative Fracture by Hammering Sound Frequency Analysis and Stress Estimation during Total Hip Arthroplasty
    Journal of Biomedical Science and Engineering, 2020
    Co-Authors: Rina Sakai, Takeaki Yamamoto, Katsufumi Uchiyama, Kensuke Fukushima, Naonobu Takahira, Kazuhiro Yoshida, Masanobu Ujihira
    Abstract:

    When a stem is inserted into the femur during total hip arthroplasty, sufficient fixation depends on the surgeon’s experience. An objective method of evaluating whether the stem has been correctly fixed may aid clinicians in their decision. We examined the relationship between the Sound Frequency caused by hammering the stem and the internal stress in artificial femurs, and evaluated the utility of Sound Frequency analysis to prevent intraoperative fracture. Surgeons inserted one of two types of cementless stems (SL-PLUS and modified CLS) using routine operational procedures into 13 artificial femurs. These are the standard Zweymullers used in Europe. The difference is the lateral shape; SL-PLUS has holes for removal and the modified CLS has fins to prevent rotation. We estimated stress in the femur via finite element analysis, measured the hammering force, and recorded the Sound of hammering for Frequency analysis. Finite element analysis revealed that the hammering Sound Frequency decreased as the maximum stress increased. A decrease in Frequency suggested that fixation was sufficient and that continued hammering would increase the risk of fracture. Thus, evaluation of the change in Sound Frequency during stem insertion may indicate when the hammering force should be reduced, thereby preventing intraoperative periprosthetic fractures. Further Frequency change may also predict fractures prior to visual confirmation. We concluded that Sound Frequency analysis has potential as an objective evaluation method to help prevent intraoperative periprosthetic fractures during stem insertion.

  • Usefulness of Hammering Sound Frequency Analysis as an Objective Evaluation Method for the Prevention of Fractures During Total Hip Arthroplasty
    Journal of Bone and Joint Surgery-british Volume, 2013
    Co-Authors: Rina Sakai, Takeaki Yamamoto, Katsufumi Uchiyama, Kensuke Fukushima, Naonobu Takahira, Kensei Tanaka, Daichi Uchijima, Moritoshi Itoman, Kiyoshi Mabuchi
    Abstract:

    Fracture during total hip arthroplasty occurs partly because the acquisition of fixation at the time of stem implantation depends on the operator9s experience and sensation due to the absence of definite criteria. Therefore, an objective evaluation method to determine whether the stem has been appropriately implanted is necessary. We clarified the relationship between the hammering Sound Frequency during stem implantation and internal stress in a femoral model, and evaluated the possible usefulness of hammering Sound Frequency analysis for preventing intraoperative fracture. Three types of cementless stem were used. Orthopedists performed stem insertion using a procedure similar to that employed in routine operation. Stress was estimated by finite element analysis using the hammering force calculated from the loading sensor as a loading condition, and Frequency analysis of hammering Sound data obtained using a microphone was performed (Fig. 1). Finite element analysis showed a decrease in the hammering Sound Frequency with an increase in the estimated maximum stress (Fig. 2, 3). When a decrease in Frequency was observed, adequate hammering had already been performed to achieve press-fit stability. Therefore, there is a possibility that the continuation of hammering induces intraoperative fractures that become a problem. Based on the relationship between stress and Frequency, the evaluation of changes in Frequency may be useful for preventing the development of intraoperative fractures. When a decrease in Frequency is observed, the hammering force should be reduced thereafter. Hammering Sound Frequency analysis may allow the prediction of bone fractures that can be visually confirmed, and may be a useful objective evaluation method for the prevention of intraoperative bone fracture.