'Self-cutting' is a specific type of emergency presenting to accident and emergency departments. All cases presenting in Sheffield in a 6-month period were studied. The self-cutter is most often a young, unemployed man: this is the group most likely to cut repeatedly. At least 45% of all cutters had a past psychiatric history, and a quarter of them were judged a high suicidal risk. The seriousn...

An important step in planning the manufacture of a component by CNC machining is the selection of cutting tools. Although it has long been known that the choice of cutter sizes can have a dramatic effect on the overall machining time, few algorithms for optimisation have been available to the production engineer. This paper describes a method for determining a theoretical optimal combination of...

A theoretical and experimental investigation of the effect of pressure on Mechanical Specific Energy and Cutting Efficiency was performed. The bottomhole expansion theory of Warren and Smith was verified and it was shown through finite element analysis that permeability of the formation restricts the use of this theory in many cases. Single cutter experimentations under pressure showed that the...

Instruments used in surgery which rotate or vibrate at a high frequency can produce potentially contaminated aerosols. Such tools are in use in cemented hip revision arthroplasties. We aimed to measure the extent of the environmental and body contamination caused by an ultrasound device and a high-speed cutter. On a human cadaver we carried out a complete surgical procedure including draping an...

Thin-walled workpieces, such as aero-engine blisks and casings, are usually made of hard-to-cut materials. The wall thickness is very small and it is easy to deflect during milling process under dynamic cutting forces, leading to inaccurate workpiece dimensions and poor surface integrity. To understand the workpiece deflection behavior in a machining process, a new real-time nonintrusive method...

In view of the unstable cutting problem in the process of high speed milling hardened steel. Conduct experiment of the stability of machine tool and high speed milling cutter. The machine tool spindle vibration spectrum and vibration acceleration signal under the condition of different centrifugal force were detected. Obtained the critical speed of security and stability cutting of milling cutt...

While leaf-cutter ants are thought to collect mainly vegetative plant material, they have also been observed collecting seeds or fruit parts on the forest floor (Alvarez-Buylla & Martı́nez-Ramos 1990, Kaspari 1996). For example, leafcutter ants have been observed carrying considerable numbers of Brosimum alicastrum Sw. and Cecropia spp. seeds into their nests (Wirth 1996) and Leal & Oliveira (19...

Host-parasite dynamics can be altered when a host is infected by multiple parasite genotypes. The different strains of parasite are expected to compete for the limited host resources, potentially affecting the survival and reproduction of the host as well as the infecting parasites. Fungus-growing ants, including the well-known leaf-cutters, are an emerging model system for studying the evoluti...

We analyze a well known type of puzzle in planar geometry: given a planar shape, it is required to find a cut that divides the shape into two identical parts (up to rotation and translation). Clearly not all shapes can be so dissected and for some shapes that appear in puzzles the cutting curve is quite surprising and difficult to find. In this paper we first analyze the inverse problem of asse...

Between these extremes are machines such as the McConnel, The evolution of the Sasex cutter for the whole stalk sugarwhich leaves the cane in a sausage for subsequent manhandling cane is discussed. The original concept was a very simple into windrows (with up to eight rows goinginto one windrow), machine known as the "cane sny7-. F~~~ this was developed or for building into stacks. There are al...