scholarly journals A Three-Dimensional Lump Model on Performances of the Stapes Displacement under Different Mechanics Property Conditions of a Middle Ear

2020 ◽  
Vol 25 (2) ◽  
pp. 162-173
Author(s):  
Yi-Chern Hsieh ◽  
Doan Minh Hai ◽  
Yue-Lin Hsieh

In this article, a three-dimensional (3D) lumped model of the human auditoria peripherals that consisted of four masses equipped with five major springs and major dashpots is presented. This model will support the quantitative basis for construction of a human middle ear physical model. This 3D lumped model consists of a human ear bone model having a similar working principle as the tiny mechanical structure. The 3D lumped model's parameters were identified using previous anatomical data, and then constructed via a parameter optimizing process using 16 springs and dashpots that represent the tiny mechanical structure's five connections. The computational results showed the sensitivity priority of the five connections to the stapes displacement with a variety of sound frequencies. Moreover, a detailed discussion of the five connections' mechanical properties affecting the magnitude of the stapes displacement was also shown in this paper. As a result of increasing the stiffness in the joint of the middle ear bone connection, the stapes' vibrational amplitude was increased. However, the magnitude of the value of the four masses reacts in a manner that is opposite to stapes displacement. Some specific frequency ranges of the voice properties to the mass and connector systems are also discussed in this paper. The details of the individual mass or joint activity to the stapes displacement at various frequency ranges are also presented. The model's behaviors were calculated using the software ANSYS workbench 15.0, Solid works 2017, and the MATLAB R2015a. Our findings provide a relevant reference for related medical research.

Author(s):  
B. Carragher ◽  
M. Whittaker

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.


1998 ◽  
Vol 23 (3) ◽  
pp. 265-265 ◽  
Author(s):  
Hutton ◽  
Birchall ◽  
French ◽  
Kubba ◽  
Severn ◽  
...  

2010 ◽  
Vol 3 (2) ◽  
pp. 156-180 ◽  
Author(s):  
Renáta Gregová ◽  
Lívia Körtvélyessy ◽  
Július Zimmermann

Universals Archive (Universal #1926) indicates a universal tendency for sound symbolism in reference to the expression of diminutives and augmentatives. The research ( Štekauer et al. 2009 ) carried out on European languages has not proved the tendency at all. Therefore, our research was extended to cover three language families – Indo-European, Niger-Congo and Austronesian. A three-step analysis examining different aspects of phonetic symbolism was carried out on a core vocabulary of 35 lexical items. A research sample was selected out of 60 languages. The evaluative markers were analyzed according to both phonetic classification of vowels and consonants and Ultan's and Niewenhuis' conclusions on the dominance of palatal and post-alveolar consonants in diminutive markers. Finally, the data obtained in our sample languages was evaluated by means of a three-dimensional model illustrating the place of articulation of the individual segments.


Author(s):  
Arwa Kurabi ◽  
Kwang Pak ◽  
Adam S. DeConde ◽  
Allen F. Ryan ◽  
Carol H. Yan

AbstractViral infections have already been implicated with otitis media and sudden sensorineural hearing loss. However, the pathophysiology of COVID-19 as it relates to otologic disorders is not well-defined. With the spread of SARS-CoV-2, it is important to evaluate its colonization of middle ear mucosa. Middle ear and nasal tissue samples for quantitative RT-PCR and histologic evaluations were obtained from post-mortem COVID-19 patients and non-diseased control patients. Here we present evidence that SARS-CoV-2 colonizes the middle ear epithelium and co-localizes with the primary viral receptor, angiotensin-converting enzyme 2 (ACE2). Both middle ear and nasal epithelial cells show relatively high expression of ACE2, required for SARS-CoV-2 entry. The epithelial cell adhesion molecule (EpCAM) was use as a biomarker of epithelia. Furthermore, we found that the viral load in the middle ear is lower than that present in the nasal cavity.


Author(s):  
Soumitra Roy Joy ◽  
Hao Yu ◽  
Pinaki Mazumder

Spoof surface plasmon polariton (SSPP) is an exotic electromagnetic state that confines light at a subwavelength scale at a design-specific frequency. It has been known for a while that spoof plasmon mode can exist in planar, thin structures with dispersion properties similar to that of its wide three-dimensional structure counterpart. We, however, have shown that spoof plasmons in thin structures possess some unique properties that remain unexplored. Our analysis reveals that the field interior to SSPP waveguide can achieve an exceptional hyperbolic spatial dependence, which can explain why spoof plasma resonance incurs red-shift with the reduction of the waveguide thickness, whereas common wisdom suggests frequency blue-shift of a resonant structure with its size reduction. In addition, we show that strong confinement can be achieved over a wide band in thin spoof plasmon structure, ranging from the spoof plasma frequency up to a lower frequency considerably away from the resonant point. The nature of lateral confinement in thin SSPP structures may enable interesting applications involving fast modulation rate due to enhanced sensitivity of optical modes without compromising modal confinement.


2013 ◽  
Vol 05 (01) ◽  
pp. 1350002 ◽  
Author(s):  
I. Benedetti ◽  
F. Barbe

A survey of recent contributions on three-dimensional grain-scale mechanical modelling of polycrystalline materials is given in this work. The analysis of material micro-structures requires the generation of reliable micro-morphologies and affordable computational meshes as well as the description of the mechanical behavior of the elementary constituents and their interactions. The polycrystalline microstructure is characterized by the topology, morphology and crystallographic orientations of the individual grains and by the grain interfaces and microstructural defects, within the bulk grains and at the inter-granular interfaces. Their analysis has been until recently restricted to two-dimensional cases, due to high computational requirements. In the last decade, however, the wider affordability of increased computational capability has promoted the development of fully three-dimensional models. In this work, different aspects involved in the grain-scale analysis of polycrystalline materials are considered. Different techniques for generating artificial micro-structures, ranging from highly idealized to experimentally based high-fidelity representations, are briefly reviewed. Structured and unstructured meshes are discussed. The main strategies for constitutive modelling of individual bulk grains and inter-granular interfaces are introduced. Some attention has also been devoted to three-dimensional multiscale approaches and some established and emerging applications have been discussed.


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