This study numerically investigated heat transfer and fluid flow characteristics in a novel cylindrical heat sink with helical minichannels for the laminar flow of fluid with temperature-dependent properties. A finite volume method was employed to obtain the solution of governing equations. The effects of helical angle, channel aspect ratio, and Reynolds number, which were regarded as main para...

The stability behavior of low immersion helical end milling processes is investigated in this paper. Low radial immersion milling operations involve interrupted cutting which induces chatter vibration under certain cutting conditions. Time Finite Element Analysis (TFEA) is suggested for an approximate solution for delayed differential equations encountered during interrupted milling. An improve...

This study investigated the influence of thread pitch, helix angle, and compactness on micromotion in immediately loaded implants in bone of varying density (D2, D3, and D4). Five models of the three-dimensional finite element (0.8 mm pitch, 1.6 mm pitch, 2.4 mm pitch, double-threaded, and triple-threaded implants) in three types of bone were created using Pro/E, Hypermesh, and ABAQUS software....

To help elucidate the role of secondary structure packing preferences in protein folding, here we present an analysis of the packing geometry observed between alpha-helices and between alpha-helices and beta-sheets in 1316 diverse, nonredundant protein structures. Finite-length vectors were fit to the alpha-carbon atoms in each of the helices and strands, and the packing angle between the vecto...

Programs are presented to plot the gross three-dimensional structure of the DNA double helix with the base sequence as input information. The rules that determine the overall structure of the double helix are those that predict the dependence of local helix parameters (specifically, helix twist angle and relative basepair roll angle) on sequence. For this purpose, the user can select either the...

In this paper we generalize the notion of helix in three-dimensional Euclidean space, which define as that curve $\alpha$ for there is an $F$-constant vector field $W$ along forms a constant angle with fixed direction $V$ (called axis helix). We find natural equation and geometric integration helices where orthogonal to its axis.