In this paper we relate the Fefferman–Graham ambient metric construction for conformal manifolds to the approach to conformal geometry via the canonical Cartan connection. We show that from any ambient metric that satisfies a weakening of the usual normalisation condition, one can construct the conformal standard tractor bundle and the normal standard tractor connection, which are equivalent to...

Copyright and Moral Rights for the articles on this site are retained by the individual authors and/or other copyright owners. For more information on Open Research Online's data policy on reuse of materials please consult the policies page. Abstract: We investigate essential aspects of penetrometer design required to measure particle properties on asteroids using a combination of laboratory an...

The foldable roll-over protective structure (FROPS) protects the operators against fatal injuries in tractor accidents. However, a rear-mounted FROPS is often folded down or removed. In present study, accessible zones and grasping areas were redesigned adapted to 5th, 50th, 95th European human anthropometric percentiles enhance its correct comfortable use. Then, rod was proposed as design solut...

Automatic control of agricultural vehicles has been a research goal for many years. Previous attempts have failed largely due to sensor limitations. With the advent of modern GPS receivers, a single low-cost sensor has been synthesized in which centimeter-level position and attitude measurements of the vehicle state are available using Carrier-Phase Differential Global Positioning System (CDGPS...

We propose several schemes to realize a tractor beam effect for ultracold atoms in the vicinity of a few-mode nanowaveguide. Atoms trapped near the waveguide are transported in a direction opposite to the guided mode propagation direction. We analyse three specific examples for ultracold (23)Na atoms trapped near a specific nanowaveguide (i.e. an optical nanofibre): (i) a conveyor belt-type tra...

In a ®eld trial (1985±1996) on a sandy loam soil the effects of tractor traf®c and fertilisation on earthworm populations were investigated. The tractor traf®c treatments compared normal farm practice (`normal') with reduced tractor traf®c (`low'). In the fertilisation treatments, three different cattle-manure management methods were compared. The cattle manure was applied as diluted slurry, as...

There is a well known one–parameter family of left invariant CR structures on SU(2) ∼= S. We show how purely algebraic methods can be used to explicitly compute the canonical Cartan connections associated to these structures and their curvatures. We also obtain explicit descriptions of tractor bundles and tractor connections.

Nacrtak Mechanized felling was introduced in Slovenia at the beginning of this decade, and before that Slovenian forestry relied on motor manual felling and tractor skidding or cable crane yarding. In this research we are dealing with wood forwarding. Model skidding maps were built, using terrain classification and decision support systems for forwarders and tractor trailers. The purpose of thi...

For many water management issues of shallow lakes with non-consolidated sediments hydrographic surveys of the open water area and reed belt areas are required. In the frame of water management strategy for the steppe lake Neusiedler See, located between Austria and Hungary, a hydrographic survey was conducted. In the open water area (water depth ≥1 m) a sediment echosounder was used. To validat...

depending on the moisture contents, the soil behavior is revealed as solid, semisolid, plastic and liquid states. liquid limit is an important property of fine-grained soils and casagrande and cone penetrometer are two different methods employed for the determination of liquid limit of the soil. in forest environment, the casagrande method is the classic method for liquid limit determination, b...