Neutral angle in the densification rolling of sintered materials

The objective of this study was to develop a discomfort function for including a high DOF upper body model during walking. A multi-objective optimization (MOO) method was formulated by minimizing dynamic effort and the discomfort function simultaneously. The discomfort function is defined as the sum of the squares of deviation of joint angles from their neutral angle positions. The dynamic effort is the sum of the joint torque squared. To investigate the efficacy of the proposed MOO method, backward walking simulation was conducted. By minimizing both dynamic effort and the discomfort function, a 3D whole body model with a high DOF upper body for walking was demonstrated successfully.

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Effect of thermal insulation on microstructural homogeneity and onset temperature of flash sintered materials

Journal of the European Ceramic Society ◽

10.1016/j.jeurceramsoc.2021.08.060 ◽

2021 ◽

Vol 41 (15) ◽

pp. 7807-7815

Author(s):

Ana G. Storion ◽

Isabela R. Lavagnini ◽

João V. Campos ◽

João G.P. da Silva ◽

Sylma C. Maestrelli ◽

...

Keyword(s):

Thermal Insulation ◽

Onset Temperature ◽

Sintered Materials ◽

Microstructural Homogeneity

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The deformation of porous sintered materials

Soviet Powder Metallurgy and Metal Ceramics ◽

10.1007/bf00774478 ◽

1964 ◽

Vol 3 (2) ◽

pp. 106-108 ◽

Cited By ~ 1

Author(s):

A. Ya. Artamonov ◽

M. V. Kozachenko

Keyword(s):

Sintered Materials

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Effect of α/β phase ratio on microstructure and mechanical properties of silicon nitride ceramics

Journal of Materials Research ◽

10.1557/jmr.2001.0311 ◽

2001 ◽

Vol 16 (8) ◽

pp. 2264-2270 ◽

Cited By ~ 27

Author(s):

Hirokazu Kawaoka ◽

Tomohiko Adachi ◽

Tohru Sekino ◽

Yong-Ho Choa ◽

Lian Gao ◽

...

Keyword(s):

Fracture Toughness ◽

Silicon Nitride ◽

Phase Ratio ◽

Phase Content ◽

Sintering Process ◽

Β Phase ◽

Nitride Ceramics ◽

Pulse Electric ◽

Sintering Condition ◽

Sintered Materials

Highly densed silicon nitride ceramics with various α/β phase ratios were produced by pulse electric current sintering process. The β-phase content of Si3N4 in sintered materials varied from 20 to 100 wt% depending on the sintering condition. The microstructure was observed by scanning electron microscopy and investigated by image analysis. Young's modulus, hardness, fracture toughness, and strength were strongly dependent on the α/β phase ratio. The fracture toughness increased from 4.6 MPa m1/2 for 20-wt% b-phase content to 8.2 MPa m1/2 for 95-wt% β-phase content, and the fracture strength showed a maximum value of about 1.6 GPa at 60-to-80-wt% β-phase content.

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Index finger position and force of the human first dorsal interosseus and its ulnar nerve antagonist

Journal of Applied Physiology ◽

10.1152/jappl.1994.77.2.987 ◽

1994 ◽

Vol 77 (2) ◽

pp. 987-997 ◽

Cited By ~ 26

Author(s):

I. Zijdewind ◽

D. Kernell

Keyword(s):

Ulnar Nerve ◽

Index Finger ◽

Maximum Voluntary Contraction ◽

Normal Subjects ◽

Voluntary Contraction ◽

Abduction Angle ◽

Hand Position ◽

First Dorsal Interosseus ◽

Length Analysis ◽

Neutral Angle

In normal subjects, maximum voluntary contraction (MVC) and electrical ulnar nerve stimulation (UNS; 30-Hz bursts of 0.33 s) were systematically compared with regard to the forces generated in different directions (abduction/adduction and flexion) and at different degrees of index finger abduction. With a “resting” hand position in which there was no index finger abduction, UNS produced about one-half of the abduction force elicited by an MVC (mean ratio 51%). Qualitatively, such a discrepancy would be expected, because UNS activates two index finger muscles with opposing actions in the abduction/adduction plane of torques: the first dorsal interosseus (FDI) and the first palmar interosseus (FPI). The abduction forces produced by MVC and UNS were very sensitive to index finger abduction angle: at a maximum degree of abduction, the UNS-generated force even reversed its direction of action to adduction (with FPI dominating) and the abduction MVC declined to 37% of that in the resting hand position. Inasmuch as these declines in MVC- and UNS-generated abduction force could not be explained by a change in moment arm, the main alternative seemed to be abduction-associated alterations in FDI fiber length (analysis by previously published biomechanical data). The FDI and FPI were further compared by application of a UNS-generated fatigue test (5-min burst stimulation), with the index finger kept at a "neutral" angle, i.e., the abduction angle at which, in the unfatigued state, the forces of the FDI and FPI were in balance (zero net UNS-generated abduction/adduction force).(ABSTRACT TRUNCATED AT 250 WORDS)

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