Anatomical study of the ostrich (Struthio camelus) foot locomotor system

2016 ◽  
Author(s):  
Rui Zhang ◽  
Haitao Wang ◽  
Guiyin Zeng ◽  
Changhai Zhou ◽  
Runduo Pan ◽  
...  
Keyword(s):  
Theoretical Basis ◽  
High Speed ◽  
Three Dimensional ◽  
Gross Anatomy ◽  
Anatomical Study ◽  
Heavy Load ◽  
Locomotor System ◽  
Terrestrial Locomotion ◽  
Solid Foundation ◽  
Relationship Of

The Ostrich is a native bird of Africa, and is highly accomplished in terrestrial locomotion in desert and grassland environments. The foot is an important segment in the ostrich body, critical for damping vibration, absorbing energy, and maintaining balance; however, detailed information on the ostrich foot is sparse. In this study, the gross anatomy of locomotor system of the ostrich foot was investigated using dissection and medical scan modeling. The paper contains a detailed study of the organizational structure and relative positional relationship of bones, tendons, and ligaments, which can be used for further three-dimensional (3D) reconstruction, providing a solid foundation for the research of high speed, heavy load, and shock absorption mechanisms. The study also provides a theoretical basis for the research of robot travelling mechanisms and vehicles traversing desert or planetary terrain.

Aerodynamic Characteristics Analysis of High-Speed Train on Cutting under Crosswinds

2013 ◽  
Vol 300-301 ◽  
pp. 62-67
Author(s):  
Kun Ye ◽  
Ren Xian Li
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Aerodynamic Characteristics ◽  
High Speed Train ◽  
Aerodynamic Forces ◽  
Cutting Depth ◽  
Cutting Slope ◽  
Characteristics Analysis ◽  
Relationship Of ◽  
The Relationship

Cutting is an effective device to reduce crosswind loads acting on trains. The cutting depth, width and gradient of slope are important factors for design and construction of cutting. Based on numerical analysis methods of three-dimensional viscous incompressible aerodynamics equations, aerodynamic side forces and yawing moments acting on the high-speed train, with different depths and widths of cutting，are calculated and analyzed under crosswinds，meanwhile the relationship of the gradient of cutting slope and transverse aerodynamic forces acting on trains are also studied. Simulation results show that aerodynamic side forces and yawing moments acting on the train（the first, middle and rear train）decrease with the increase of cutting depth. The relationship between transverse forces (moments) coefficients acting on the three sections and the cutting depth basically is the three cubed relation. The bigger is cutting width，the worse is running stability of train. The relationship between yawing moments coefficients acting each body of the train and the cutting width approximately is the three cubed relation. The transverse Aerodynamic forces decreased gradually with the increase of the gradient of cutting slope, the relationship between yawing moments coefficients acting each body of the train and the gradient of cutting slope basically is the four cubed relation.

scholarly journals Research on matching conditions of coaxial six-branch split-torsion herringbone gear transmission system

2021 ◽  
Vol 39 (2) ◽  
pp. 341-349
Author(s):  
Zhibin Li ◽  
Sanmin Wang ◽  
Fei Li ◽  
Qi'an Peng ◽  
Jianfeng Li
Keyword(s):  
Calculation Method ◽  
High Speed ◽  
High Reliability ◽  
Three Dimensional ◽  
Matching Condition ◽  
Transmission System ◽  
Gear Transmission ◽  
Heavy Load ◽  
Gear Transmission System ◽  
Herringbone Gear

Compared with traditional gear transmission, the multi-branch split-torsion gear transmission system has the advantages of large transmission power, small size and high reliability, so it is more and more used in high-speed heavy load occasions such as ships and aircraft. Since the transmission system of multi-branch split torsional gears belongs to over-constrained configuration, it is necessary to meet strict tooth matching condition in the design process in order to realize the correct synchronous meshing of each branch, which is of great significance to ensure its uniform installation and motion synchronization.Aiming at the coaxial six-branch twisted herringbone gear transmission system, this paper establishes a calculation method for the proper meshing conditions of each branch on the basis of considering the movement synchronization of each branch and preventing geometric interference.In addition, the calculation of gear allocation was carried out for a ship's power transmission system, and a parameter scheme that satisfies the requirements of transmission ratio, concentricity and synchronous meshing was obtained.The correctness of the calculation method of tooth matching in this paper is verified by three-dimensional modeling. This method has universal application value to the tooth matching design of other coaxial multi-branch gear transmissions.

Dynamic Models of Stability Lobes of Milling Thin-Walled Plates

2012 ◽  
Vol 443-444 ◽  
pp. 622-627
Author(s):  
Hai Long Ma ◽  
Ai Jun Tang ◽  
Qing Kui Chen
Keyword(s):  
High Speed ◽  
Dynamic Models ◽  
Three Dimensional ◽  
Cutting Parameters ◽  
Cutting Condition ◽  
Part Quality ◽  
Radial Depth ◽  
Milling Machines ◽  
Thin Walled ◽  
Relationship Of

In the process of milling thin-walled plate, chatter is one of the major limitations on productivity and part quality even for high speed and high precision milling machines. Therefore, it is necessary to avoid chatter with a suitable choice of cutting condition. This paper studies the dynamic stability models of milling the thin-walled plate by analyzing the geometrical relationship of cutting, and derives the mathematic expressions in theory. Moreover, this paper develops a three-dimensional lobes diagram of the spindle speed, the axial depth and the radial depth. Through the three-dimensional lobes, it is possible to choose the appropriate cutting parameters according to the dynamic behavior of the chatter system.

Research on the Ideal Cushion Method of Pneumatic Cylinder

2015 ◽  
Vol 779 ◽  
pp. 68-73 ◽  
Author(s):  
Hai Tao Wang ◽  
Long Wu Xu ◽  
Wei Xiong ◽  
Tian Ze Zhang
Keyword(s):  
Flow Rate ◽  
Theoretical Basis ◽  
High Speed ◽  
Characteristic Curve ◽  
Pneumatic Cylinder ◽  
Heavy Load ◽  
Hydraulic Cylinders ◽  
Pneumatic Cylinders ◽  
Temperature Equation ◽  
The Ideal

In the situation of high-speed or heavy load, pneumatic cylinders usually generate cushion failure like collision or rebound, so that the key question to be solved for the cylinders is cushion. In order to obtain a better cushion method, the paper used the ideal cushion characteristic curve of hydraulic cylinders for reference; and throttling area equation, temperature equation, flow rate equation and motion equation were established. By building the simulation module in Matlab/Simulink, the rule of throttling area approaching to the ideal cushion curve was found, which provide theoretical basis for the design of cylinders cushion devices.

Stability Prediction Model for Milling Process

2012 ◽  
Vol 490-495 ◽  
pp. 2829-2833
Author(s):  
Hai Long Ma ◽  
Ai Jun Tang ◽  
Qing Kui Chen
Keyword(s):  
High Speed ◽  
Three Dimensional ◽  
Cutting Parameters ◽  
Milling Process ◽  
Cutting Condition ◽  
Part Quality ◽  
Radial Depth ◽  
Milling Machines ◽  
Thin Walled ◽  
Relationship Of

In the process of milling thin-walled plate, chatter is one of the major limitations on productivity and part quality even for high speed and high precision milling machines. Therefore, it is necessary to avoid chatter with a suitable choice of cutting condition. This paper studies the dynamic stability models of milling the thin-walled plate by analyzing the geometrical relationship of cutting, and derives the mathematic expressions in theory. Moreover, this paper develops a three-dimensional lobes diagram of the spindle speed, the axial depth and the radial depth. Through the three-dimensional lobes, it is possible to choose the appropriate cutting parameters according to the dynamic behavior of the chatter system.

High-speed brightfield 3-D imaging and 3-D image analysis of thick and overlapped cell clusters in cytological preparations

1994 ◽  
Vol 52 ◽  
pp. 218-219
Author(s):  
Robert W. Mackin
Keyword(s):  
Image Analysis ◽  
High Speed ◽  
Three Dimensional ◽  
Image Data ◽  
Ccd Camera ◽  
Objective Lens ◽  
Array Processor ◽  
Vaginal Smears ◽  
Low Contrast ◽  
Computer Controlled

This paper presents two advances towards the automated three-dimensional (3-D) analysis of thick and heavily-overlapped regions in cytological preparations such as cervical/vaginal smears. First, a high speed 3-D brightfield microscope has been developed, allowing the acquisition of image data at speeds approaching 30 optical slices per second. Second, algorithms have been developed to detect and segment nuclei in spite of the extremely high image variability and low contrast typical of such regions. The analysis of such regions is inherently a 3-D problem that cannot be solved reliably with conventional 2-D imaging and image analysis methods.High-Speed 3-D imaging of the specimen is accomplished by moving the specimen axially relative to the objective lens of a standard microscope (Zeiss) at a speed of 30 steps per second, where the stepsize is adjustable from 0.2 - 5μm. The specimen is mounted on a computer-controlled, piezoelectric microstage (Burleigh PZS-100, 68/μm displacement). At each step, an optical slice is acquired using a CCD camera (SONY XC-11/71 IP, Dalsa CA-D1-0256, and CA-D2-0512 have been used) connected to a 4-node array processor system based on the Intel i860 chip.

Severe Paradoxical Dysphonia in Two Young Women

1993 ◽  
Vol 2 (3) ◽  
pp. 52-55 ◽  
Author(s):  
Michael Collins ◽  
Robert McDonald ◽  
Robert Stanley ◽  
Timothy Donovan ◽  
C. Frank Bonebrake
Keyword(s):  
Young Women ◽  
Theoretical Basis ◽  
Therapeutic Regimen ◽  
Instrumental Data ◽  
Relationship Of ◽  
The Relationship

This report describes an unusual and persistent dysphonia in two young women who had taken a therapeutic regimen of isotretinoin for intractable acne. We report perceptual and instrumental data for their dysphonia, and pose a theoretical basis for the relationship of dysphonia to this drug. We also provide recommendations for reducing the risk of acquiring a dysphonia during the course of treatment with isotretinoin.

Anatomical Study of the Quadrigeminal Cistern in Patients with Three-Dimensional MR Cisternography

Skull Base ◽  
2009 ◽  
Vol 19 (01) ◽  
Author(s):  
Laura Columbano ◽  
Wolf Lüdemann ◽  
Lennart Stieglitz ◽  
Mario Giordano ◽  
Amir Samii ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Anatomical Study ◽  
Mr Cisternography ◽  
Quadrigeminal Cistern

Effects of Three-Dimensional Pressure Gradients on High-Speed Turbulent Boundary Layers

2021 ◽  
Author(s):  
Scott J. Peltier ◽  
Brian E. Rice ◽  
Ethan Johnson ◽  
Venkateswaran Narayanaswamy ◽  
Marvin E. Sellers
Keyword(s):  
Boundary Layers ◽  
High Speed ◽  
Three Dimensional ◽  
Turbulent Boundary Layers ◽  
Pressure Gradients
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