On parallel p-equidistant ruled surfaces by using mofied orthogonal frame with curvature in E³

In this paper, it is investigated Ruled surfaces according to modified orthogonal frame with curvature in 3-dimensional Euclidean space. Firstly, we give apex angle, pitch and drall of closed ruled surface in E³. Then, it characterized the relationship between these invariant of parallel p-equidistant ruled surfaces.

INVOLUTE-EVOLUTE CURVES ACCORDING TO MODIFIED ORTHOGONAL FRAME

In this paper, the involute-evolute curve concept has been defined according to two type modified orthogonal frames at non-zero points of curvature and torsion in the Euclidean space E^3 , respectively. Later, the characteristic theorems related to the distance between the corresponding points of these curves have been given. Besides, the relations have been found between the curvatures and also torsions of the two type the involute-evolute modified orthogonal pairs.

Spin-1/2 one- and two- particle systems in physical space without eigen-algebra or tensor product

A novel representation of spin 1/2 combines in a single geometric object the roles of the standardPauli spin vector operator and spin state. Under the spin-position decoupling approximation it consists ofthree orthonormal vectors comprising a gauge phase. In the one-particle case the representation: (1) isHermitian; (2) shows handedness; (3) reproduces all standard expectation values, including the total one particlespin modulus 𝑆tot = √3ℏ/2; (4) constrains basis opposite spins to have same handedness; (5)allows to formalize irreversibility in spin measurement. In the two-particle case: (1) entangled pairs haveprecisely related gauge phases and can be of same or opposite handedness; (2) the dimensionality of the spinspace doubles due to variation of handedness; (3) the four maximally entangled states are naturally definedby the four improper rotations in 3D: reflections onto the three orthogonal frame planes (triplets) andinversion (singlet). The cross-product terms in the expression for the squared total spin of two particlesrelates to experiment and they yield all standard expectation values after measurement. Here spin is directlydefined and transformed in 3D orientation space, without use of eigen algebra and tensor product as in thestandard formulation. The formalism allows working with whole geometric objects instead of onlycomponents, thereby helping keep a clear geometric picture of ‘on paper’ (controlled gauge phase) and ‘onlab’ (uncontrolled gauge phase) spin transformations.

Meshing theory of axial arc tooth profile cylindrical worm drive

In this paper, the axial arc tooth profile cylindrical worm drive is proposed, whose worm is cut by turning tool. Due to the simple processing equipment, short manufacturing time and low cost, this kind of worm can replace the cylindrical worm ground by grinding wheel under some conditions. The meshing theory of the worm drive is founded comprehensively. Moreover, a movable orthogonal frame is established on the non-orthogonal parametric curves net helical surface. Based on the founded meshing theory, the simulating study on the meshing quality of the worm drive is performed systematically. The numerical outcome shows that the meshing quality of this worm drive is quite favorable, and the condition of forming lubricating oil film is excellent. The working orthogonal clearance of the turning tool is decreased with the increase of the worm thread number, which must be a positive value in the process of worm cutting. This explains that the number of the worm thread is ≤4.

General approaches for shear-correcting coordinate transformations in Bragg coherent diffraction imaging. Part II

X-ray Bragg coherent diffraction imaging (BCDI) has been demonstrated as a powerful 3D microscopy approach for the investigation of sub-micrometre-scale crystalline particles. The approach is based on the measurement of a series of coherent Bragg diffraction intensity patterns that are numerically inverted to retrieve an image of the spatial distribution of the relative phase and amplitude of the Bragg structure factor of the diffracting sample. This 3D information, which is collected through an angular rotation of the sample, is necessarily obtained in a non-orthogonal frame in Fourier space that must be eventually reconciled. To deal with this, the approach currently favored by practitioners (detailed in Part I) is to perform the entire inversion in conjugate non-orthogonal real- and Fourier-space frames, and to transform the 3D sample image into an orthogonal frame as a post-processing step for result analysis. In this article, which is a direct follow-up of Part I, two different transformation strategies are demonstrated, which enable the entire inversion procedure of the measured data set to be performed in an orthogonal frame. The new approaches described here build mathematical and numerical frameworks that apply to the cases of evenly and non-evenly sampled data along the direction of sample rotation (i.e. the rocking curve). The value of these methods is that they rely on the experimental geometry, and they incorporate significantly more information about that geometry into the design of the phase-retrieval Fourier transformation than the strategy presented in Part I. Two important outcomes are (1) that the resulting sample image is correctly interpreted in a shear-free frame and (2) physically realistic constraints of BCDI phase retrieval that are difficult to implement with current methods are easily incorporated. Computing scripts are also given to aid readers in the implementation of the proposed formalisms.

A Note on the Acceleration and Jerk in Motion Along a Space Curve

The resolution of the acceleration vector of a particle moving along a space curve is well known thanks to Siacci [1]. This resolution comprises two special oblique components which lie in the osculating plane of the curve. The jerk is the time derivative of acceleration vector. For the jerk vector of the aforementioned particle, a similar resolution is presented as a new contribution to field [2]. It comprises three special oblique components which lie in the osculating and rectifying planes. In this paper, we have studied the Siacci’s resolution of the acceleration vector and aforementioned resolution of the jerk vector for the space curves which are equipped with the modified orthogonal frame. Moreover, we have given some illustrative examples to show how the our theorems work.