Numerical Computer Modelling and an Innovative Spacer-Cement Train Results in Successful Zonal Isolation in Critical Well Offshore Australia with Minimal Casing Centralisation

The objectives of this publication are the analysis of surfaces and edges of a new geometric spiroid hob with arched profile in axial section and the definition of their equations for computer modelling. On the basis of this we will work out the CAD model of hob for our further geometric calculations.

Download Full-text

Modelling Lunar Extremes

Journal of Skyscape Archaeology ◽

10.1558/jsa.34686 ◽

2018 ◽

Vol 3 (2) ◽

pp. 207-216 ◽

Cited By ~ 1

Author(s):

David Fisher ◽

Lionel Sims

Keyword(s):

High Precision ◽

Celestial Mechanics ◽

Computer Modelling ◽

Landscape Context ◽

The Sun ◽

The Moon

Claims first made over half a century ago that certain prehistoric monuments utilised high-precision alignments on the horizon risings and settings of the Sun and the Moon have recently resurfaced. While archaeoastronomy early on retreated from these claims, as a way to preserve the discipline in an academic boundary dispute, it did so without a rigorous examination of Thom’s concept of a “lunar standstill”. Gough’s uncritical resurrection of Thom’s usage of the term provides a long-overdue opportunity for the discipline to correct this slippage. Gough (2013), in keeping with Thom (1971), claims that certain standing stones and short stone rows point to distant horizon features which allow high-precision alignments on the risings and settings of the Sun and the Moon dating from about 1700 BC. To assist archaeoastronomy in breaking out of its interpretive rut and from “going round in circles” (Ruggles 2011), this paper evaluates the validity of this claim. Through computer modelling, the celestial mechanics of horizon alignments are here explored in their landscape context with a view to testing the very possibility of high-precision alignments to the lunar extremes. It is found that, due to the motion of the Moon on the horizon, only low-precision alignments are feasible, which would seem to indicate that the properties of lunar standstills could not have included high-precision markers for prehistoric megalith builders.

Download Full-text

Visualizing 3D Molecular Structures Using an Augmented Reality App

10.26434/chemrxiv.10031888.v1 ◽

2019 ◽

Author(s):

Kristina Eriksen ◽

Bjarne Nielsen ◽

Michael Pittelkow

Keyword(s):

Augmented Reality ◽

Small Molecules ◽

Computer Modelling ◽

Simple Procedure ◽

3D Structure ◽

Molecular Structures ◽

Free Software ◽

Programming Skills ◽

2D Space ◽

Made In

<p>We present a simple procedure to make an augmented reality app to visualize any 3D chemical model. The molecular structure may be based on data from crystallographic data or from computer modelling. This guide is made in such a way, that no programming skills are needed and the procedure uses free software and is a way to visualize 3D structures that are normally difficult to comprehend in the 2D space of paper. The process can be applied to make 3D representation of any 2D object, and we envisage the app to be useful when visualizing simple stereochemical problems, when presenting a complex 3D structure on a poster presentation or even in audio-visual presentations. The method works for all molecules including small molecules, supramolecular structures, MOFs and biomacromolecules.</p>

Download Full-text