Static Application of Transient Hydrodynamic Loads on Vessel Internal Structures As a Result of Pulse Jet Mixer Overblow: Low-Frequency Loads

2021 ◽  
Author(s):  
Rafael Garcilazo ◽  
Brian Fant ◽  
Dr. Robert Blevins
Keyword(s):  
Low Frequency ◽  
Hydrodynamic Loads ◽  
Internal Structures ◽  
Pulse Jet

Static Application of Transient Hydrodynamic Loads on Vessel Internal Structures As a Result of Pulse Jet Mixer Overblow: Low-Frequency Loads

2020 ◽  
Author(s):  
Rafael Garcilazo ◽  
Brian Fant ◽  
Robert Blevins
Keyword(s):  
Waste Treatment ◽  
Low Frequency ◽  
Response Spectra ◽  
Liquid Density ◽  
Choked Flow ◽  
Internal Structures ◽  
Displacement Response Spectra ◽  
Conservation Of Momentum ◽  
Operation Results ◽  
Pulse Jet

Abstract At the Hanford Waste Treatment and Immobilization Plant (WTP), various vessels are designed to be agitated with internal pulse jet mixers (PJMs) in order to provide a means of mixing with no moving parts local to the vessel. PJMs are operated by use of an applied vacuum to draw liquid in followed by motive air to force liquid out (while not completely discharging all the liquid). This continual operation results in mixing of the vessel contents. In off-normal conditions, PJMs may completely discharge resulting in air rapidly injected into the vessel (PJM overblow). An evaluation is complete to determine the statically applied transient Rayleigh-Plesset bubble loads resulting from PJM overblow on the vessel’s internal submerged structures. The low-frequency bubble loads on internal structures is determined via analysis of overblow test data, application of the Rayleigh-Plesset equation based on bubble pressure, PJM nozzle critical flow ratios, conservation of momentum, the relative equation of motion of a submerged non-fixed structure subject to both relative drag and relative acceleration, non-flow boundary conditions, use of a displacement-response spectra, and Hooke’s Law. This theoretical Rayleigh-Plesset bubble loads model accounts for various vessel and internal submerged structure designs and different operational states: PJM cavity pressure, liquid density, depth of submerged bubble, and both choked or non-choked flow through the PJM nozzle.

scholarly journals OC6 Phase I: Investigating the underprediction of low-frequency hydrodynamic loads and responses of a floating wind turbine

2020 ◽  
Vol 1618 ◽  
pp. 032033 ◽  
Author(s):  
A N Robertson ◽  
S Gueydon ◽  
E Bachynski ◽  
L Wang ◽  
J Jonkman ◽  
...  
Keyword(s):  
Phase I ◽  
Wind Turbine ◽  
Low Frequency ◽  
Hydrodynamic Loads ◽  
Floating Wind Turbine

Static Application of Transient Hydrodynamic Loads on Vessel Internal Structures As a Result of Pulse Jet Mixer Overblow: High-Frequency Load Acoustic Event

2020 ◽  
Author(s):  
Brian Fant ◽  
Rafael Garcilazo ◽  
Robert Blevins
Keyword(s):  
Test Data ◽  
High Frequency ◽  
Response Spectra ◽  
Geometric Constraints ◽  
Analysis Model ◽  
Element Analysis ◽  
Acoustic Event ◽  
Forcing Function ◽  
Internal Structures ◽  
Pulse Jet

Abstract At the Hanford Waste Treatment and Immobilization Plant (WTP), various vessels are designed to be agitated with internal pulse jet mixers (PJMs) in order to provide a means of mixing with no moving parts local to the vessel. PJMs are operated by use of an applied vacuum to draw liquid in followed by motive air to force liquid out (while not completely discharging all the liquid). This continual operation results in mixing of the vessel contents. In off-normal conditions, PJMs may completely discharge resulting in air rapidly injected into the vessel (PJM overblow). An evaluation is complete to determine the statically applied transient acoustic event loads resulting from Pulse Jet Mixer (PJM) overblow on a vessel’s internal submerged structures. The high-frequency acoustic load on internal structures is determined via analysis of overblow hydrophone test data, vessel modal and harmonic analysis, determination of an overblow forcing function through a Fourier analysis of test data compared to modal analysis of the vessel, application of the overblow forcing function in a finite element analysis model with acoustic fluid elements, use of a displacement-response spectra, and Hooke’s Law. Compared to previous analyses, this improved method can account for changes to PJM cavity pressure, PJM nozzle diameter, and more accurately represents the loads because it considers geometric constraints.

scholarly journals Rheological Investigation of Relaxation Behavior of Polycarbonate/Acrylonitrile-Butadiene-Styrene Blends

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1916
Author(s):  
Jae Sik Seo ◽  
Ho Tak Jeon ◽  
Tae Hee Han
Keyword(s):  
Yield Stress ◽  
Low Frequency ◽  
Acrylonitrile Butadiene Styrene ◽  
Blend Ratio ◽  
Internal Structures ◽  
Internal Network ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Blend Ratios ◽  
Butadiene Styrene

The rheological properties of polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) blends with various blend ratios are investigated at different temperatures to determine the shear dependent chain motions in a heterogeneous blend system. At low frequency levels under 0.1 rad/s, the viscosity of the material with a blend ratio of 3:7 (PC:ABS) is higher than that of pure ABS polymer. As the temperature increases, the viscosities of ABS-rich blends increase rather than decrease, whereas PC-rich blends exhibit decrease in viscosity. Results from the time sweep measurements indicate that ordered structures of PC and the formation and breakdown of internal network structures of ABS polymer occur simultaneously in the blend systems. Newly designed sequence test results show that the internal structures formed between PC and ABS polymers are dominant at low shear conditions for the blend ratio of 3:7 and effects of structural change and the presence of polybutadiene (PBD) become dominant at high shear conditions for pure ABS. The results of yield stress and relaxation time for PC/ABS blends support this phenomenon. The specimen with a blend ratio of 3:7 exhibited the highest value of yield stress at high temperature among others, which implies that the internal structure become stronger at higher temperature. The heterogeneity of ABS-rich blends increases whereas that of PC-rich blends decreases as temperature increases.

Effect of main frequencies on characterizing fault damage zones using forward modeling and attribute of variance

2020 ◽  
Vol 8 (4) ◽  
pp. SP157-SP165
Author(s):  
Yangpu Chen ◽  
Zonghu Liao ◽  
Li-Yun Fu ◽  
Gang Zhou ◽  
Liang Xu ◽  
...  
Keyword(s):  
Damage Zone ◽  
Low Frequency ◽  
Forward Modeling ◽  
Seismic Attributes ◽  
Frequency Effect ◽  
Fracture Density ◽  
Internal Structures ◽  
Fault Structures ◽  
Scattering Noise ◽  
40 Hz

Faulting processes have created large damage zones with complex structures in the field; however, estimating the width and geometry of such fault structures in the subsurface is challenging due to a lack of data. Seismic attributes (e.g., coherence and variance) from seismic surveys have been used for the characterization of faults, but most cases do not detail the effectiveness of this approach. By using forward modeling and the associated seismic attributes of variance, four fault models of idealized damage zones are characterized and the frequency effect is evaluated on the width estimation of fault damage zones in the subsurface. The main results indicate that (1) the general geometric pattern of damage zones could be identified by using simulated amplitude and seismic variance with main frequencies of 10, 25, and 40 Hz; (2) the estimated widths of damage zones at a low frequency of 10 Hz are larger (up to twofold) than those at frequencies of 25 and 40 Hz; for large damage zones (>400 m), the width is best estimated by a frequency of 25 Hz; and (3) scattering noise and diffraction around the fault are found in data at a high frequency of 40 Hz, which results in width overestimation of the damage zones by approximately 17%. The internal structures are difficult to distinguish as scattering noise and chaotic reflections dominate seismic signals. More factors that may influence the accuracy of damage zone width estimation via seismic attributes, include the bedding thickness, fracture density, and velocity. An in-depth understanding of this approach is useful in the application of seismic variance to characterize fault damage zones that may significantly control the fluid migration in the subsurface.

scholarly journals A Fusion Method for Atomic Force Acoustic Microscopy Cell Imaging Based on Local Variance in Non-Subsampled Shearlet Transform Domain

2020 ◽  
Vol 10 (21) ◽  
pp. 7424
Author(s):  
Pengxin Cao ◽  
Xiaoqing Li ◽  
Mingyue Ding
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Acoustic Microscopy ◽  
Source Image ◽  
Fusion Method ◽  
Cell Region ◽  
Shearlet Transform ◽  
Local Variance ◽  
Atomic Force ◽  
Internal Structures

Atomic force acoustic microscopy (AFAM) is a measurement method that uses the probe and acoustic wave to image the surface and internal structures of different materials. For cellular material, the morphology and phase images of AFAM reflect the outer surface and internal structures of the cell, respectively. This paper proposes an AFAM cell image fusion method in the Non-Subsampled Shearlet Transform (NSST) domain, based on local variance. First, NSST is used to decompose the source images into low-frequency and high-frequency sub-bands. Then, the low-frequency sub-band is fused by the weight of local variance, while a contrast limited adaptive histogram equalization is used to improve the source image contrast to better express the details in the fused image. The high-frequency sub-bands are fused using the maximum rule. Since the AFAM image background contains a lot of noise, and improved segmentation algorithm based on the Otsu algorithm is proposed to segment the cell region, and the image quality metrics based on the segmented region will make the evaluation more accurate. Experiments with different groups of AFAM cell images demonstrated that the proposed method can clearly show the internal structures and the contours of the cells, compared with traditional methods.

Ultrastructure of Giant Mitochondria and Their Inclusions in Schwann Cells of Bovine Splenic Nerve

1974 ◽  
Vol 32 ◽  
pp. 194-195
Author(s):  
Å. Thureson-Klein
Keyword(s):  
Schwann Cells ◽  
Cell Organelles ◽  
Giant Mitochondria ◽  
Matrix Density ◽  
Physiological Conditions ◽  
Unmyelinated Axons ◽  
Internal Structures ◽  
Structural Abnormalities ◽  
Cytotoxic Compounds ◽  
Cell Components

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Mitochondria in Cardiomyopathy: Alterations in Size, Number and Internal Structures

1968 ◽  
Vol 26 ◽  
pp. 126-127
Author(s):  
George Hug ◽  
William K. Schubert
Keyword(s):  
Heart Failure ◽  
Biochemical Analysis ◽  
Left Ventricular ◽  
Size Number ◽  
Internal Structures ◽  
Left Ventricular Outflow ◽  
Chest X Ray ◽  
Myocardial Fibers ◽  
Muscle Biopsies ◽  
Needle Liver Biopsy

A white boy six months of age was hospitalized with respiratory distress and congestive heart failure. Control of the heart failure was achieved but marked cardiomegaly, moderate hepatomegaly, and minimal muscular weakness persisted.At birth a chest x-ray had been taken because of rapid breathing and jaundice and showed the heart to be of normal size. Clinical studies included: EKG which showed biventricular hypertrophy, needle liver biopsy which showed toxic hepatitis, and cardiac catheterization which showed no obstruction to left ventricular outflow. Liver and muscle biopsies revealed no biochemical or histological evidence of type II glycogexiosis (Pompe's disease). At thoracotomy, 14 milligrams of left ventricular muscle were removed. Total phosphorylase activity in the biopsy specimen was normal by biochemical analysis as was the degree of phosphorylase activation. By light microscopy, vacuoles and fine granules were seen in practically all myocardial fibers. The fibers were not hypertrophic. The endocardium was not thickened excluding endocardial fibroelastosis. Based on these findings, the diagnosis of idiopathic non-obstructive cardiomyopathy was made.

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