scholarly journals Sound of a nut rolling inside an elastic rubber balloon

2019 ◽  
Vol 3 ◽  
pp. 6
Author(s):  
Amaury Barral ◽  
Quentin Louis ◽  
Clément Brochet ◽  
Julie André ◽  
Anthony Guillen ◽  
...  
Keyword(s):  
The Other ◽  
Elastic Membrane ◽  
Rubber Balloon ◽  
Frequency Components ◽  
Elastic Rubber ◽  
Different Shapes

This article studies the sound produced by nuts of different shapes swirling in an elastic rubber balloon. First, the sound is studied experimentally, both in terms of frequency and amplitude. Regarding the frequency components of the sound, we show that they can be divided into two main contributions – one due to the oscillations of the elastic membrane, the other due to the hits of the nut against the balloon – and present models to describe the frequency’s dependence on the main parameters of the system. We analysed the influence of several parameters such as the balloon’s geometry, the nut’s geometry and its mass.

scholarly journals Shape Correspondence Analysis for Biomolecules Based on Volumetric Eigenfunctions

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Tao Liao ◽  
Hao-Chih Lee ◽  
Ge Yang ◽  
Yongjie Jessica Zhang
Keyword(s):  
Correspondence Analysis ◽  
Flexible Structures ◽  
Spectral Shape ◽  
The Other ◽  
Shape Deformation ◽  
Second Step ◽  
Analysis Method ◽  
Shape Correspondence ◽  
Dense Point ◽  
Different Shapes

AbstractThe functionality of biomolecules depends on their flexible structures, which can be characterized by their surface shapes. Tracking the deformation and comparing biomolecular shapes are essential in understanding their mechanisms. In this paper, a new spectral shape correspondence analysis method is introduced for biomolecules based on volumetric eigenfunctions. The eigenfunctions are computed from the joint graph of two given shapes, avoiding the sign flipping and confusion in the order of modes. An initial correspondence is built based on the distribution of a shape diameter, which matches similar surface features in different shapes and guides the eigenfunction computation. A two-step scheme is developed to determine the final correspondence. The first step utilizes volumetric eigenfunctions to correct the assignment of boundary nodes that disobeys the main structures. The second step minimizes the distortion induced by deforming one shape to the other. As a result, a dense point correspondence is constructed between the two given shapes, based on which we approximate and predict the shape deformation, as well as quantitatively measure the detailed shape differences.

Axial Performance of Various Strengthening Methods Applied on Full-Scale Rectangular RC Columns

2011 ◽  
Vol 82 ◽  
pp. 618-623 ◽  
Author(s):  
Pei Ching Chen ◽  
Min Lang Lin ◽  
Yin Han Wu
Keyword(s):  
Axial Force ◽  
Full Scale ◽  
Reinforcement Ratio ◽  
The Other ◽  
Transverse Reinforcement ◽  
Rc Columns ◽  
Different Shapes ◽  
Adhesive Anchors ◽  
Cfrp Wrapping ◽  
Better Than

The performance of RC columns subjected to axial force is relative to the confinement. CFRP wrapping, a generally adopted retrofit method, was proved not to effectively provide confining force due to the bulging effect on the column face. Therefore, this paper is focused on the performance of the retrofitted full-scale rectangular RC columns using different retrofit schemes including the proposed CFRP wrapping conjugated with CFRP anchors method. A total of eleven rectangular RC columns with low transverse reinforcement ratio were constructed. Among them, one was tested as benchmark; one was purposely constructed with larger transverse reinforcement ratio; five were retrofitted by using CFRP wrapping and CFRP anchors; and the other four were retrofitted by using different shapes of steel jacketing alone or with adhesive anchors. All the specimens were subjected to monotonic incremental axial force until failure occurred. Experimental results demonstrated that the ductility of the specimens retrofitted by using CFRP wrapping with CFRP anchors was significantly improved compared with those retrofitted by using only CFRP wrapping. On the other hand, the specimen with octagonal steel jacketing performed better than all other specimens not only on ductility but also on strength. Finally, a novel numerical model considering the contribution of the retrofit material will be proposed and validated in the future.

A Study about Security of Wind Turbine Foundation in Different Width and Height Ratios

2014 ◽  
Vol 1079-1080 ◽  
pp. 566-573
Author(s):  
Shi Jie Xu ◽  
You Hua Fan ◽  
Zhen Kun Wang
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Wind Farm ◽  
The Other ◽  
Wind Loads ◽  
Key Factors ◽  
Height Ratio ◽  
Geometry Feature ◽  
Different Shapes ◽  
The Relationship

Width and height ratio is a characteristic geometry feature of wind turbine foundations. This study establishes the relationship between security of wind turbine foundations and their width and height ratios. There are a number of works on checking wind turbines, however, limited works about how the width and height ratio influences the structure were conducted. This paper provides fifteen models of three different shapes, five circular foundations, five hexagon foundations and five triangle foundations. Data from a wind farm in Guizhou, China, is used to calculate the main wind loads acted on wind turbine structures. Then key factors concerning with security of foundations were obtained. And they were put together so that it is easy for us to find their relationships. The results show foundations have different performance at different ratios. It’s change laws were so clear, security of foundations is improved by the increasing of width and height ratio. On the other hand, hexagon and triangle foundations were certificated suitable for general projects.

scholarly journals The Effects of Different Shapes of Capsulorrhexis on Postoperative Refractive Outcomes and Effective Position of the Intraocular Lens in Cataract Surgery

2018 ◽  
Author(s):  
Shixu Li ◽  
Yiping Hu ◽  
Ran Guo ◽  
Yushuang Shao ◽  
Jiangyue Zhao ◽  
...  
Keyword(s):  
Cataract Surgery ◽  
Intraocular Lens ◽  
Anterior Segment ◽  
The Other ◽  
Intraocular Lenses ◽  
Vertical Diameter ◽  
Refractive Outcomes ◽  
Age Related ◽  
Horizontal Diameter ◽  
Different Shapes

Abstract Background：To evaluate the effects of anterior capsular opening size on deviation from predicted refraction and the effective position of intraocular lens (ELP) in cataract surgery. Methods：Eighty patients (80 eyes) with simple age-related cataracts were treated from May 2018 to September 2018 at the Fourth Affiliated Hospital of China Medical University. The patients were divided into 2 groups : 40 eyes were implanted with the C-loop haptic intraocular lens (AMO Tecnis ZCB00) while the other 40 eyes were implanted with the plate haptic intraocular lens (CT ASPHINA 509M). Follow-up visits were conducted postoperatively at 1 week, 1 month, and 3 months during which patients underwent refraction and data collection after pupil dilation that included anterior segment photography and Scheimpflug imaging by Pentacam. The area, horizontal and vertical diameter of the capsulorrhexis, circularity, decentration, and package were analysed using the image analysis software Image-Pro-Plus 6.0 that evaluated the relationship between the different shapes of capsulorrhexis with deviation from predicted refraction and ELP in cataract surgery. Results: Deviation from predicted refraction and all of the parameters of capsulorrhexis were not correlative in the 509M IOL group, however, in the Tecnis IOL group, while the deviation from predicted refraction and all of the capsulorrhexis parameters were not correlative at 1 week, the deviation from predicted refraction did correlate with capsulorrhexis area,horizontal diameter at 1 month (P=0.029, P=0.048), and the capsulorrhexis area ,vertical diameter at 3 months (P=0.03, P=0.017).The ELP correlated with package in both groups postoperatively (r>0, P<0.05), but there is no other capsulorrhexis parameters correlate with ELP in the 509M IOL group (all P>0.05). For the Tecnis IOL group, the ELP and capsulorrhexis area were correlated at 1 week and 1 month, while the ELP and horizontal diameter, the ELP and vertical diameter were correlated at 1 week , but did not correlate with the other capsulorrhexis parameters in the Tecnis IOL group (all P>0.05). Conclusions: The shape of the capsulorrhexis has an effect on postoperative refractive outcomes and the effective position of intraocular lens in cataract surgery, and plate haptic intraocular lenses have better refractive stability than C-loop haptic intraocular lenses.（ChiCTR-TRC-1800015638）

scholarly journals A possible linear filtering model to explain White’s illusion at different grating widths

2017 ◽  
Author(s):  
Soma Mitra ◽  
Deabasis Mazumdar ◽  
Kuntal Ghosh ◽  
Kamales Bhaumik
Keyword(s):  
High Frequency ◽  
The Other ◽  
Linear Filtering ◽  
Multi Scale ◽  
Difference Of Gaussians ◽  
Frequency Components ◽  
Lightness Induction ◽  
Simulation Results ◽  
Model Support ◽  
Mach Band

The perceived lightness of a stimulus depends on its background, a phenomenon known as lightness induction. For instance, the same gray stimulus can look light in one background and dark in another. Moreover, such induction can take place in two directions; in one case, it occurs in the direction of the background lightness known as lightness assimilation, while in the other it occurs opposite to that, known as lightness contrast. The White’s illusion is a typical one which does not completely conform to any of these two processes. In this paper, we have quantified the perceptual strength of the White’s illusion as a function of the width of the background square grating. Based on our results which also corroborate some earlier studies, we propose a linear filtering model inspired from an earlier work dealing with varying Mach band widths. Our model assumes that the for the White’s illusion, where the edges are strong and many in number, and as such the spectrum is rich in high frequency components, the inhibitory surround in the classical Difference-of-Gaussians (DoG) filter gets suppressed, so that the filter essentially reduces to a multi-scale Gaussian one. The simulation results with this model support the present as well as earlier experimental results.

scholarly journals LEAD ISOTOPE CHARACTERIZATION OF COPPER INGOTS FROM SARDINIA (ITALY): INFERENCES ON THEIR ORIGINS

2004 ◽  
Vol 36 (3) ◽  
pp. 1173 ◽  
Author(s):  
L. Pinarelli
Keyword(s):  
Isotope Composition ◽  
Lead Isotopes ◽  
Historical Context ◽  
Mineral Resources ◽  
The Other ◽  
Metal Artifacts ◽  
Plane Convex ◽  
Linear Distribution ◽  
The North ◽  
Different Shapes

The provenance of the materials making up the metal artifacts represents a fundamental question for archaeological research. The complex processes necessary to extract the metals from the minerals cause considerable changes in their chemical composition. By contrast, the ratio of the different lead isotopes in artifacts is not influenced by metallurgie processes. Therefore, the raw mineral material and the extracted metal exhibit the same isotope "footprint". Over the course of history, Sardinia has played a major role in maritime routes. Its considerably rich mineral resources, with copper, lead and iron mineralizations, moreover complemented its strategic importance. During the 10th and 9th centuries BC Sardinia, because of its strategic location, was to become directly involved in the "precolonial" Phoenician expansion. Two repositories of copper ingots recovered at different levels within a nuragic village in northwest Sardinia, can be placed within this historical context of intense traffic and exchange of goods between native Sardinian and Phoenician communities. The ingots were made in different shapes: plane-convex, biconvex, truncated cone and irregular. The analyzed ingots exhibit a considerable lead isotopie variability, although no systematic differences in isotope composition were revealed between the ingots from the two different repositories. Moreover, no systematic isotopie variations were observed between the different shapes in which the material was found. Overall, the ingots exhibit a linear distribution in the lead/lead diagrams. The group of ingots with the lowest isotope ratios project onto the area defined by the northwestern Sardinian mineralizations. The ingot located on the other extreme end of the straight line in the Pb diagrams overlaps the area defined by the southern Sardinian deposits. The isotope footprints of the intermediate samples seem to indicate that they stem from the mixing of two components from two different mining areas of Sardinia, one in the north, the other in the south. Therefore, widespread exchange of metal must have taken place throughout the island, and such an exchange does not seem to have been hindered by the advent of the Phoenicians in Sardinia. The results of the present investigation indicate that the majority of the examined ingots was produced with metal from the northwest of the island, and that these mines were therefore known and exploited in nuragic times. Such findings shed new light on the complex issues involved in proto-historic Sardinian metallurgy

scholarly journals Cortical elasticity determines the geometry of prospective mesoderm constriction in Drosophila melanogaster

2017 ◽  
Author(s):  
Konstantin Doubrovinski
Keyword(s):  
Close Agreement ◽  
Fruit Fly ◽  
Multilayered Structure ◽  
Rectangular Domain ◽  
The Other ◽  
Model Parameters ◽  
Ventral Part ◽  
Tissue Contraction ◽  
Morphogenetic Event ◽  
Different Shapes

1SummaryAn animal embryo begins its life as a ball of epithelial cells. In the course of development, invariably, this cellular ball will undergo a process of gastrulation to form a multilayered structure with the different germ layers designated to form organs with different shapes and functions. In the fruit fly Drosophia melanogaster, gastrulation begins with the constriction of mesodermal cells that make up a rectangular domain in the ventral part of the embryo. A remarkable aspect of this morphogenetic event is its anisotropy - the mesoderm constricts much more along one axis than along the other. In this paper we propose an explanation of this observed anisotropy. Specifically, we show that tissue contraction must be anisotropic, provided that the tissue is elastic and that the contractile domain is elongated (e.g. rectangular as opposed to square). This conclusion is generic in the sense that it does not depend on the specific values of model parameters. Since our recent study demonstrated that embryonic tissue is elastic on a developmentally relevant time-scale, it appears likely that the anisotropy of mesoderm contraction is an elastic effect. Our model makes a number of specific predictions that appear in close agreement with the available data.

scholarly journals MICRO-MORPHOLOGY STUDY OF POLLEN GRAINS AND CYPSELA OF SEVEN SELECTED SPECIES, BELONG TO ASTERACEAE FAMILY IN AL-JADRIYA CAMPUS

2019 ◽  
Vol 50 (4) ◽  
Author(s):  
Sadeq & Aliwy
Keyword(s):  
Pollen Grains ◽  
The Other ◽  
Special Importance ◽  
Sonchus Oleraceus ◽  
Lactuca Serriola ◽  
Pollen Surface ◽  
Different Shapes ◽  
Beak Length ◽  
Micro Morphology ◽  
Asteraceae Family

Seven plants species that belong to Asteraceae (Compositae) family have been investigated micro-morphology with the help of scanning electron microscopy (SEM) observations. Plants were collected from University of Baghdad campus during January to May in 2017-2018 and the species are: Calendula persica C. M. May, Carduus pycnocephalus L., Erigeron canadensis L., Lactuca serriola L., Silybum marianum  (L.) Garth, Sonchus oleraceus L., Urospermum picroides (L.) Schmidt. The aim of this study was to describing the external morphology of seeds as well as a detailed study of pollen grains morphology. Special emphasis is given to the size, shape, polar and equatorial length, spines length, length and width of ora and colpi, tectum sclupturing, and the ornamentations on pollen surface, Sonchus oleraceus and Lactuca serriola pollen grains have a special exin sculpture, which is lophate and the other species used in this study is non-lophate, and all the pollen grains of the species used in this study are tri-zono- colporate, Calendula persica is only species that it is exin sculpture is echinate with spines length (3.8-4.3 um), and the exin sculpture of the other species is spinulose. Also special importance is given to the size, shape, pappus, beak length, primary and secondary sculpturing, carpopodium, as well as the surface of the seed (Cypsela), Seeds (cypsela) of the species used in this study were significantly different in morphology, The shapes of the 7 species were differed in each species and it showed 7 different shapes: narrowly-oblong, oblong, long-oblong, board-oblong, widely curved-oblong, narrowly-ellipitic, and narrowly-obovated.

The Design of a Dexterous Gripper to be Used for Activities of Daily Living by People With Upper-Extremity Disabilities

2007 ◽  
Author(s):  
Redwan Alqasemi ◽  
Sebastian Mahler ◽  
Rajiv Dubey
Keyword(s):  
Activities Of Daily Living ◽  
Upper Extremity ◽  
Daily Living ◽  
The Other ◽  
Robotic Arm ◽  
Driving Mechanism ◽  
Actuation Mechanism ◽  
Parallel Motion ◽  
Different Shapes ◽  
Wheelchair Mounted Robotic Arm

A new robotic gripper was designed and constructed for Activities of Daily Living (ADL) to be used with the new Wheelchair-Mounted Robotic Arm developed at USF. Two aspects of the new gripper made it unique; one is the design of the paddles, and the other is the design of the actuation mechanism that produces parallel motion for effective gripping. The paddles of the gripper were designed to grasp a wide variety objects with different shapes and sizes that are used in every day life. The driving mechanism was designed to be simple, light, effective, safe, self content, and independent of the robotic arm attached to it.

scholarly journals Characteristics of free and submerged hydraulic jumps over different macroroughnesses

2020 ◽  
Vol 22 (6) ◽  
pp. 1554-1572
Author(s):  
Amir Ghaderi ◽  
Mehdi Dasineh ◽  
Francesco Aristodemo ◽  
Ali Ghahramanzadeh
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Numerical Model ◽  
Energy Loss ◽  
Maximum Velocity ◽  
Correlation Coefficients ◽  
The Other ◽  
Hydraulic Jumps ◽  
Depth Ratio ◽  
Different Shapes

Abstract The present study deals with numerical simulations of the free and submerged hydraulic jumps over different shapes of roughness in various roughness arrangements and different Froude number conditions. The models were studied using three roughness shapes, i.e. triangular, square and semi-oval for 0.2 &lt; T/I &lt; 0.5, where T and I are height and distance of roughness, respectively. The results showed that the numerical model is fairly well able to simulate the free and submerged jump characteristics. The effect of roughness plays a role in the reduction of the relative maximum velocity which is greater in the submerged jump. The thickness of the boundary layer for both free and submerged jumps decreases with increasing the distance between the roughnesses. Triangular macroroughness has a significant effect on the length of the jump and shortest length with respect to the other shapes. The reduction in the submerged depth ratio and tailwater depth ratio depends mainly on the space of the roughnesses. The highest shear stress and energy loss in both jumps occur in a triangular macroroughness (TR) with T/I = 0.50 compared to other ratios and modes. The numerical results were compared with previous studies and relationships with good correlation coefficients were presented for the mentioned parameters.

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