The Haptic Recognition of Geometrical Shapes in Congenitally Blind and Blindfolded Adolescents: Is There a Haptic Prototype Effect?

Nowadays, rapid prototyping is an emerging trend that is followed by industries and auto sector on a large scale which produces intricate geometrical shapes for industrial applications. The wire arc additive manufacturing (WAAM) technique produces large scale industrial products which having intricate geometrical shapes, which is fabricated by layer by layer metal deposition. In this paper, the CMT technique is used to fabricate single-walled WAAM samples. CMT has a high deposition rate, lower thermal heat input and high cladding efficiency characteristics. Humping is a common defect encountered in the WAAM method which not only deteriorates the bead geometry/weld aesthetics but also limits the positional capability in the process. Humping defect also plays a vital role in the reduction of hardness and tensile strength of the fabricated WAAM sample. The humping defect can be controlled by using low heat input parameters which ultimately improves the mechanical properties of WAAM samples. Two types of path planning directions namely uni-directional and bi-directional are adopted in this paper. Results show that the optimum WAAM sample can be achieved by adopting a bi-directional strategy and operating with lower heat input process parameters. This avoids both material wastage and humping defect of the fabricated samples.

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The effect of congenital blindness on resting-state functional connectivity revisited

Scientific Reports ◽

10.1038/s41598-021-91976-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Maria J. S. Guerreiro ◽

Madita Linke ◽

Sunitha Lingareddy ◽

Ramesh Kekunnaya ◽

Brigitte Röder

Keyword(s):

Functional Connectivity ◽

Resting State ◽

Visual Experience ◽

Brain Regions ◽

State Condition ◽

Resting State Functional Connectivity ◽

Congenital Blindness ◽

Eyes Closed ◽

Congenitally Blind ◽

Eyes Open

AbstractLower resting-state functional connectivity (RSFC) between ‘visual’ and non-‘visual’ neural circuits has been reported as a hallmark of congenital blindness. In sighted individuals, RSFC between visual and non-visual brain regions has been shown to increase during rest with eyes closed relative to rest with eyes open. To determine the role of visual experience on the modulation of RSFC by resting state condition—as well as to evaluate the effect of resting state condition on group differences in RSFC—, we compared RSFC between visual and somatosensory/auditory regions in congenitally blind individuals (n = 9) and sighted participants (n = 9) during eyes open and eyes closed conditions. In the sighted group, we replicated the increase of RSFC between visual and non-visual areas during rest with eyes closed relative to rest with eyes open. This was not the case in the congenitally blind group, resulting in a lower RSFC between ‘visual’ and non-‘visual’ circuits relative to sighted controls only in the eyes closed condition. These results indicate that visual experience is necessary for the modulation of RSFC by resting state condition and highlight the importance of considering whether sighted controls should be tested with eyes open or closed in studies of functional brain reorganization as a consequence of blindness.

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The role of visual experience for spatial numerical associations

Seeing and Perceiving ◽

10.1163/187847612x648486 ◽

2012 ◽

Vol 25 (0) ◽

pp. 222 ◽

Cited By ~ 1

Author(s):

Michael J. Proulx ◽

Achille Pasqualotto ◽

Shuichiro Taya

Keyword(s):

Visual Experience ◽

Opposite Effect ◽

Random Number Generation ◽

Number Line ◽

Mental Number Line ◽

Generation Task ◽

Congenitally Blind ◽

Left And Right ◽

The Right

The topographic representation of space interacts with the mental representation of number. Evidence for such number–space relations have been reported in both synaesthetic and non-synaesthetic participants. Thus far most studies have only examined related effects in sighted participants. For example, the mental number line increases in magnitude from left to right in sighted individuals (Loetscher et al., 2008, Curr. Biol.). What is unclear is whether this association arises from innate mechanisms or requires visual experience early in life to develop in this way. Here we investigated the role of visual experience for the left to right spatial numerical association using a random number generation task in congenitally blind, late blind, and blindfolded sighted participants. Participants orally generated numbers randomly whilst turning their head to the left and right. Sighted participants generated smaller numbers when they turned their head to the left than to the right, consistent with past results. In contrast, congenitally blind participants generated smaller numbers when they turned their head to the right than to the left, exhibiting the opposite effect. The results of the late blind participants showed an intermediate profile between that of the sighted and congenitally blind participants. Visual experience early in life is therefore necessary for the development of the spatial numerical association of the mental number line.

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Tool Selectivity in Left Occipitotemporal Cortex Develops without Vision

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00411 ◽

2013 ◽

Vol 25 (8) ◽

pp. 1225-1234 ◽

Cited By ~ 48

Author(s):

Marius V. Peelen ◽

Stefania Bracci ◽

Xueming Lu ◽

Chenxi He ◽

Alfonso Caramazza ◽

...

Keyword(s):

Functional Organization ◽

Auditory Task ◽

Anatomical Location ◽

Resting State Functional Connectivity ◽

Frontoparietal Network ◽

Congenitally Blind ◽

Occipitotemporal Cortex ◽

Auditory Tasks ◽

Tool Motion ◽

Selective Activity

Previous studies have provided evidence for a tool-selective region in left lateral occipitotemporal cortex (LOTC). This region responds selectively to pictures of tools and to characteristic visual tool motion. The present human fMRI study tested whether visual experience is required for the development of tool-selective responses in left LOTC. Words referring to tools, animals, and nonmanipulable objects were presented auditorily to 14 congenitally blind and 16 sighted participants. Sighted participants additionally viewed pictures of these objects. In whole-brain group analyses, sighted participants showed tool-selective activity in left LOTC in both visual and auditory tasks. Importantly, virtually identical tool-selective LOTC activity was found in the congenitally blind group performing the auditory task. Furthermore, both groups showed equally strong tool-selective activity for auditory stimuli in a tool-selective LOTC region defined by the picture-viewing task in the sighted group. Detailed analyses in individual participants showed significant tool-selective LOTC activity in 13 of 14 blind participants and 14 of 16 sighted participants. The strength and anatomical location of this activity were indistinguishable across groups. Finally, both blind and sighted groups showed significant resting state functional connectivity between left LOTC and a bilateral frontoparietal network. Together, these results indicate that tool-selective activity in left LOTC develops without ever having seen a tool or its motion. This finding puts constraints on the possible role that this region could have in tool processing and, more generally, provides new insights into the principles shaping the functional organization of OTC.

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Activation of the Human Superior Temporal Gyrus during Observation of Goal Attribution by Intentional Objects

Journal of Cognitive Neuroscience ◽

10.1162/0898929042947874 ◽

2004 ◽

Vol 16 (10) ◽

pp. 1695-1705 ◽

Cited By ~ 113

Author(s):

Johannes Schultz ◽

Hiroshi Imamizu ◽

Mitsuo Kawato ◽

Chris D. Frith

Keyword(s):

Functional Imaging ◽

Superior Temporal Gyrus ◽

Target Object ◽

Directed Motion ◽

Intentional Objects ◽

Geometrical Shapes ◽

Goal Attribution ◽

Complex Goal

Previous functional imaging experiments in humans showed activation increases in the posterior superior temporal gyrus and sulcus during observation of geometrical shapes whose movements appear intentional or goal-directed. We modeled a chase scenario between two objects, in which the chasing object used different strategies to reach the target object: The chaser either followed the target's path or appeared to predict its end position. Activation in the superior temporal gyrus of human observers was greater when the chaser adopted a predict rather than a follow strategy. Attending to the chaser's strategy induced slightly greater activation in the left superior temporal gyrus than attending to the outcome of the chase. These data implicate the superior temporal gyrus in the identification of objects displaying complex goal-directed motion.

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The Stress Concentration Factors in Cylindrical Tubes with Transverse Circular Holes

Aeronautical Quarterly ◽

10.1017/s0001925900001608 ◽

1959 ◽

Vol 10 (4) ◽

pp. 326-344 ◽

Cited By ~ 23

Author(s):

H. T. Jessop ◽

C. Snell ◽

I. M. Allison

Keyword(s):

Stress Concentration ◽

Maximum Stress ◽

Stress System ◽

Complete Knowledge ◽

Geometrical Shapes ◽

Cylindrical Tubes ◽

Circular Holes ◽

Concentration Factors ◽

Stress Concentration Factors ◽

Better Than

The “frozen stress” techniques of photoelasticity can give a complete knowledge of the stress, system in a solid body, but the examination of the stresses requires more time and care than in corresponding flat plate tests. In tests on tubes with transverse circular holes, sponsored by The Royal Aeronautical Society, all practicable geometrical shapes are examined and the maximum stress is measured in tension, bending and torsion. The results are comprehensive and show the inadequacy of previous results. In all cases the maximum stress occurs inside the bore of the hole. The accuracy of all the graphs of stress concentration factors is better than five per cent.

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Numerical Investigation of Flow Around Bluff Bodies

Journal of Mechanics ◽

10.1017/s1727719100000186 ◽

1998 ◽

Vol 14 (3) ◽

pp. 153-159 ◽

Cited By ~ 1

Author(s):

Chou-Jiu Tsai ◽

Ger-Jyh Chen

Keyword(s):

Vortex Shedding ◽

Stokes Equations ◽

Navier Stokes ◽

Bluff Bodies ◽

Near Wake ◽

Navier Stokes Equations ◽

Physical Description ◽

Geometrical Shapes ◽

Flow Phenomena ◽

Volume Method

ABSTRACTIn this study, fluid flow around bluff bodies are studied to examine the vortex shedding phenomenon in conjuction with the geometrical shapes of these vortex shedders. These flow phenomena are numerically simulated. A finite volume method is employed to solve the incompressible two-dimensional Navier-Stokes equations. Thus, quantitative descriptions of the vortex shedding phenomenon in the near wake were made, which lead to a detailed description of the vortex shedding mechanism. Streamline contours, figures of lift coefficent, and figures of drag coefficent in various time, are presented, respectively, for a physical description.

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Comparison of Defense Mechanisms Utilized in Perception by Congenitally Blind and Sighted Respondents

Psychological Reports ◽

10.2466/pr0.1984.55.1.228 ◽

1984 ◽

Vol 55 (1) ◽

pp. 228-230

Author(s):

Sam Minskoff ◽

John M. Curtis

Keyword(s):

Defense Mechanisms ◽

Defense Mechanism ◽

Ego Defenses ◽

Congenitally Blind

The present study examined specific defense mechanisms involved in perceptions of congenitally blind and sighted respondents. The Defense Mechanism Inventory was given 30 blind and 30 sighted subjects, randomly selected. One-way analyses of variance on specific defenses indicated nonsignificant differences between the groups who tended to show comparable patterns of ego defenses. Findings suggest any discrepancies in perception between such groups are not likely based on differences in the use of various defense mechanisms as measured by the Defense Mechanism Inventory.

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Preparation and characterization of different geometrical shapes of multi-bore hollow fiber membranes and application in vacuum membrane distillation

Journal of Analytical Science & Technology ◽

10.1186/s40543-020-00244-4 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Elham M. El-Zanati ◽

Eman Farg ◽

Esraa Taha ◽

Ayman El-Guindi ◽

Heba Abdallah

Keyword(s):

Mechanical Properties ◽

Flow Rate ◽

Hollow Fiber ◽

Amorphous Structure ◽

Membrane Distillation ◽

Operating Conditions ◽

Hollow Fiber Membranes ◽

Preparation Conditions ◽

Geometrical Shapes ◽

Fiber Membranes

Abstract Multi-bore hollow fiber membranes were prepared through phase inversion spinning process using new locally designed spinnerets of various geometrical shapes. The spun cylindrical-like, rectangular or ribbon-like, and triangular-like are prepared, dried, and characterized by scanning electronic microscope. Fibers of circular (seven, five, and four bores) shape, rectangular of five bores, and triangular of three bores were chosen to study the effect of both geometrical configuration and the number of bores on the amorphous structure and the mechanical properties of the membranes. Membrane geometry, surface amorphous, and bore arrangements are very sensitive to the operating conditions, especially the extrusion and drawing rates. Three polymeric blends of different compositions are used to prepare multi-bore hollow fiber membranes. This study revealed that the blend composition of PES 16%, PVP 2%, PEG 2%, diethylene glycol 2%, and NMP 78% gives excellent mechanical properties. Optimization of the preparation conditions also developed, where the dope flow rate, the bore flow rate, and the air gap were 1.14 cm3 s−1, 1.1 cm3 s−1, and 0 cm, respectively. Furthermore, this study proved that the circular arrangement has high mechanical strength. The prepared seven-MBHF membranes were applied in the membrane distillation process, a solution of 35 g/l NaCl was used to test the membrane performance, and the achieved flux and rejection were 28.32 L/m2 h and 98.9%, respectively. This performance demonstrated that the prepared membrane in this way is suitable to compete with conventional reverse osmosis technology that uses single track hollow fibers.

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