Noncontact Acoustic Inspection of Outer Wall Using Acoustic Irradiation Induced Vibration from Drone

Each of the seven families of rudists (Mollusca, Bivalvia, Hippuritacea) is characterized by distinctive shell-wall architectures which reflect phylogenetic relationships within the superfamily. Analysis of the complex, calcareous, cellular wall of the attached valve of the radiolite rudist Eoradiolites davidsoni (Hill) from the Comanche Cretaceous of Central Texas indicates that its wall architecture is an elaboration of the simpler monopleurid rudist wall and supports possible radiolite-monopleurid relationships.Several well-preserved specimens of E. davidsoni were sectioned, polished, etched, and carbon and gold coated for SEM examination. Maximum shell microstructure detail was displayed by etching with a 0.7% HC1 solution from 80 to 100 seconds.The shell of E. davidsoni comprises a large, thick-walled, conical, attached valve (AV) and a small, very thin, operculate, free valve (FV) (Fig. 1a). The AV shell is two-layered with a thin inner wall, in which original structures are usually obliterated by recrystallization, and a thick, cellular, outer wall.

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Condition Assessment of Sanitary Sewer Lines Using Acoustic Inspection

Pipelines 2015 ◽

10.1061/9780784479360.091 ◽

2015 ◽

Author(s):

George Selembo ◽

Ivan Howitt

Keyword(s):

Condition Assessment ◽

Sanitary Sewer ◽

Acoustic Inspection

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Review on the aerodynamics of intermediate compressor duct

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.14.4.2020.13.0587 ◽

2020 ◽

Vol 14 (4) ◽

pp. 7446-7468

Author(s):

Manish Sharma ◽

Beena D. Baloni

Keyword(s):

High Pressure ◽

Pressure Loss ◽

Flow Analysis ◽

Outer Wall ◽

Optimization Techniques ◽

Optimum Pressure ◽

Research Areas ◽

Static Pressure Distribution ◽

High Pressure Compressor ◽

Pressure Compressor

In a turbofan engine, the air is brought from the low to the high-pressure compressor through an intermediate compressor duct. Weight and design space limitations impel to its design as an S-shaped. Despite it, the intermediate duct has to guide the flow carefully to the high-pressure compressor without disturbances and flow separations hence, flow analysis within the duct has been attractive to the researchers ever since its inception. Consequently, a number of researchers and experimentalists from the aerospace industry could not keep themselves away from this research. Further demand for increasing by-pass ratio will change the shape and weight of the duct that uplift encourages them to continue research in this field. Innumerable studies related to S-shaped duct have proven that its performance depends on many factors like curvature, upstream compressor’s vortices, swirl, insertion of struts, geometrical aspects, Mach number and many more. The application of flow control devices, wall shape optimization techniques, and integrated concepts lead a better system performance and shorten the duct length. This review paper is an endeavor to encapsulate all the above aspects and finally, it can be concluded that the intermediate duct is a key component to keep the overall weight and specific fuel consumption low. The shape and curvature of the duct significantly affect the pressure distortion. The wall static pressure distribution along the inner wall significantly higher than that of the outer wall. Duct pressure loss enhances with the aggressive design of duct, incursion of struts, thick inlet boundary layer and higher swirl at the inlet. Thus, one should focus on research areas for better aerodynamic effects of the above parameters which give duct design with optimum pressure loss and non-uniformity within the duct.

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Complex wall modeling for hemodynamic simulations of intracranial aneurysms based on histologic images

International Journal of Computer Assisted Radiology and Surgery ◽

10.1007/s11548-021-02334-z ◽

2021 ◽

Vol 16 (4) ◽

pp. 597-607

Author(s):

Annika Niemann ◽

Samuel Voß ◽

Riikka Tulamo ◽

Simon Weigand ◽

Bernhard Preim ◽

...

Keyword(s):

Wall Thickness ◽

Vessel Wall ◽

Intracranial Aneurysms ◽

Geometric Model ◽

Image Data ◽

Outer Wall ◽

3D Models ◽

Patient Specific ◽

Intracranial Vessel ◽

Hemodynamic Simulations

Abstract Purpose For the evaluation and rupture risk assessment of intracranial aneurysms, clinical, morphological and hemodynamic parameters are analyzed. The reliability of intracranial hemodynamic simulations strongly depends on the underlying models. Due to the missing information about the intracranial vessel wall, the patient-specific wall thickness is often neglected as well as the specific physiological and pathological properties of the vessel wall. Methods In this work, we present a model for structural simulations with patient-specific wall thickness including different tissue types based on postmortem histologic image data. Images of histologic 2D slices from intracranial aneurysms were manually segmented in nine tissue classes. After virtual inflation, they were combined into 3D models. This approach yields multiple 3D models of the inner and outer wall and different tissue parts as a prerequisite for subsequent simulations. Result We presented a pipeline to generate 3D models of aneurysms with respect to the different tissue textures occurring in the wall. First experiments show that including the variance of the tissue in the structural simulation affect the simulation result. Especially at the interfaces between neighboring tissue classes, the larger influence of stiffer components on the stability equilibrium became obvious. Conclusion The presented approach enables the creation of a geometric model with differentiated wall tissue. This information can be used for different applications, like hemodynamic simulations, to increase the modeling accuracy.

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Surgical outcome of primary intradural spinal arachnoid cysts: a series of 10 cases

The Egyptian Journal of Neurology Psychiatry and Neurosurgery ◽

10.1186/s41983-021-00290-8 ◽

2021 ◽

Vol 57 (1) ◽

Author(s):

Essam Abdelhameed ◽

Ahmed Ali Morsy

Keyword(s):

Tertiary Care ◽

Outer Wall ◽

Arachnoid Cysts ◽

Neurophysiological Monitoring ◽

Japanese Orthopedic Association ◽

Common Location ◽

Before And After ◽

Microsurgical Resection ◽

Tertiary Care Centers ◽

Intradural Arachnoid Cysts

Abstract Background Primary intradural spinal arachnoid cysts are rare pathologies of uncertain etiology and variable presentation from no symptoms to myelopathy or radiculopathy according to cord or root compression. MRI with diffusion and contrast differentiates them from many pathologies. There is a lot of debate regarding when to treat and how to treat such rare pathologies. Objective We present a series of 10 primary intradural arachnoid cysts and evaluate outcome after surgery. Methods This retrospective study includes patients having primary intradural spinal arachnoid cysts operated in two tertiary care centers from October 2012 till October 2019. Symptomatic cysts were subjected to microsurgical resection or outer wall excision and inner wall marsupialization under neurophysiological monitoring. The Japanese Orthopedic Association Score was used for clinical evaluation while MRI with contrast and diffusion was used for radiological evaluation before and after surgery. Results This series included 10 patients, 4 males and 6 females, with mean age of 40 years. Pain was the most common presentation. The most common location was dorsal thoracic region. Total excision was achieved in 2 cases and marsupialization in 8 cases. All symptoms improved either completely or partially after surgery. No neurological deterioration or recurrence was reported during the follow-up period in this series. Conclusion Treatment of symptomatic primary intradural spinal arachnoid cysts should be microsurgical resection, when the cyst is adherent to the cord, microscopic fenestration can be safe and effective.

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Cyclodextrins, Natural Compounds, and Plant Bioactives—A Nutritional Perspective

Biomolecules ◽

10.3390/biom11030401 ◽

2021 ◽

Vol 11 (3) ◽

pp. 401

Author(s):

Svenja Wüpper ◽

Kai Lüersen ◽

Gerald Rimbach

Keyword(s):

Intestinal Flora ◽

Aqueous Solubility ◽

Outer Wall ◽

Natural Compounds ◽

Model Organisms ◽

Laboratory Model ◽

Internal Cavity ◽

Pentacyclic Triterpenoids ◽

Starch Derivatives ◽

Improved Stability

Cyclodextrins (CDs) are a group of cyclic oligosaccharides produced from starch or starch derivatives. They contain six (αCD), seven (βCD), eight (γCD), or more glucopyranose monomers linked via α-1,4-glycosidic bonds. CDs have a truncated cone shape with a hydrophilic outer wall and a less hydrophilic inner wall, the latter forming a more apolar internal cavity. Because of this special architecture, CDs are soluble in water and can simultaneously host lipophilic guest molecules. The major advantage of inclusion into CDs is increased aqueous solubility of such lipophilic substances. Accordingly, we present studies where the complexation of natural compounds such as propolis and dietary plant bioactives (e.g., tocotrienol, pentacyclic triterpenoids, curcumin) with γCD resulted in improved stability, bioavailability, and bioactivity in various laboratory model organisms and in humans. We also address safety aspects that may arise from increased bioavailability of plant extracts or natural compounds owing to CD complexation. When orally administered, α- and βCD—which are inert to intestinal digestion—are fermented by the human intestinal flora, while γCD is almost completely degraded to glucose units by α-amylase. Hence, recent reports indicate that empty γCD supplementation exhibits metabolic activity on its own, which may provide opportunities for new applications.

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The Influence of Bulb Position on Hydraulic Performance of Submersible Tubular Pump Device

Journal of Marine Science and Engineering ◽

10.3390/jmse9080831 ◽

2021 ◽

Vol 9 (8) ◽

pp. 831

Author(s):

Zhuangzhuang Sun ◽

Jie Yu ◽

Fangping Tang

Keyword(s):

Entropy Production ◽

Large Scale ◽

Experimental Testing ◽

Guide Vane ◽

Outer Wall ◽

Hydraulic Performance ◽

Hydraulic Loss ◽

Optimized Design ◽

Outlet Channel ◽

Wall Area

In order to study the influence of the position of the bulb on the hydraulic performance of asubmersible tubular pump device, based on a large-scale pumping station, two schemes—involving a front-mounted bulb and a rear-mounted bulb, respectively—were designed. The front-mounted scheme uses the GL-2008-03 hydraulic model and its conventional guide vane, while the rearmounted scheme uses the optimized design of a diffuser vane. The method of combining numerical simulation and experimental testing was used to analyze the differences between the external and internal characteristics of the two schemes. The results show that, under the condition of reasonable diffusion guide vane design, the efficiency under the rear-mounted scheme is higher than that under the front-mounted scheme, where the highest efficiency difference is about 1%. Although the frontmounted bulb scheme reduces the hydraulic loss of the bulb section, the placement of the bulb on the water inlet side reduces the flow conditions of the impeller. Affected by the circulation of the guide vane outlet, the hydraulic loss of the outlet channel is greater than the rear-mounted scheme. The bulb plays a rectifying function when the bulb is placed behind, which greatly eliminates the annular volume of the guide vane outlet, and the water outlet channel has a smaller hydraulic loss. In the front-mounted scheme, the water flow inside the outlet channel squeezes to the outer wall, causing higher entropy production near the outer wall area. The entropy production of the rear-mounted scheme is mainly in the bulb section and the bulb support. This research can provide reference for the design and form selection of a submersible tubular pump device, which has great engineering significance.

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