Search results for "Cutting"

Friction Model for Tool/Work Material Contact Applied to Surface Integrity Prediction in Orthogonal Cutting Simulation

2017

Abstract Tribological behavior at both tool/chip and tool/work material interfaces should be highly considered while simulating the machining process. In fact, it is no longer accurate to suppose one independent constant friction coefficient at the tool/chip interface, since in reality it depends on the applied contact conditions, including the sliding velocity and pressure. The contact conditions at both above mentioned interfaces may affect the thermal and mechanical phenomena and consequently the surface integrity predictions. In this article, the influence of contact conditions (sliding velocity) on the tribological behavior of uncoated tungsten carbide tool against OFHC copper work mat…

Drone arc routing problems

2018

[EN] In this article, we present some drone arc routing problems (Drone ARPs) and study their relation with well-known postman ARPs. Applications for Drone ARPs include traffic monitoring by flying over roadways, infrastructure inspection such as by flying along power transmission lines, pipelines or fences, and surveillance along linear features such as coastlines or territorial borders. Unlike the postmen in traditional ARPs, drones can travel directly between any two points in the plane without following the edges of the network. As a consequence, a drone route may service only part of an edge, with multiple routes being used to cover the entire edge. Thus the Drone ARPs are continuous o…

A more efficient cutting planes approach for the green vehicle routing problem with capacitated alternative fuel stations

2021

AbstractThe Green Vehicle Routing Problem with Capacitated Alternative Fuel Stations assumes that, at each station, the number of vehicles simultaneously refueling cannot exceed the number of available pumps. The state-of-the-art solution method, based on the generation of all feasible non-dominated paths, performs well only with up to 2 pumps. In fact, it needs cloning the paths between every pair of pumps. To overcome this issue, in this paper, we propose new path-based MILP models without cloning paths, for both the scenario with private stations (i.e., owned by the fleet manager) and that with public stations. Then, a more efficient cutting plane approach is designed for addressing both…

Solving a large cutting problem in the glass manufacturing industry

2020

Abstract The glass cutting problem proposed by Saint Gobain for the 2018 ROADEF challenge includes some specific constraints that prevent the direct application of procedures developed for the standard cutting problem. On the one hand, the sheets to be cut have defects that make them unique and they must be used in a given order. On the other hand, pieces are grouped in stacks and the pieces in each stack must be cut in order. There are also some additional characteristics due to the technology being used, especially the requirement for a three-stage guillotine cutting process. Taking into account the sequencing constraints on sheets and pieces, we have developed a beam search algorithm, us…

On the Computational Error in 3D Simulation of Cutting

2009

Effects of Rapid Weight Loss on Judo Athletes: A Systematic Review

2020

Rapid weight loss (RWL) is commonly practiced among judo athletes. Although it helps them to gain the advantage over their lighter opponents, previous studies have shown that RWL can have a negative impact on the athlete’s performance and overall well-being. This systematic review aimed to synthesize the evidence that examines the influence of rapid weight loss on physiological parameters, biomarkers, and psychological well-being in judo athletes. We followed the preferred reporting items for systematic reviews and meta-analyses guidelines. We searched for studies on Web of Science and PubMed that elaborate on the influence of ≥5% RWL achieved over ≤7-day period in judokas. Out of 52 studie…

Organogenesis and encapsulation of in vitro-derived propagules of Carrizo citrange [Citrus sinensis (L.) Osb. × Poncirius trifoliata (L.) Raf]

2011

Due to widespread polyembryony, Citrus rootstocks are usually propagated by open-pollinated seed germination, although micropropagation offers many advantages. Encapsulation technology has recently attracted the interest of researchers in the field of plant propagation because it combines the advantages of zygotic or gamic seeds with those of micropropagation. In this study, we examined the encapsulation of Carrizo citrange uninodal microcuttings (3–4 mm long) and evaluated the influence of the calcium alginate coating, a short time storage at cold temperature, and different sowing substrates on the viability and regrowth of the explants. A secondary aim was to develop an efficient protocol…

Re-giardinieri e Natura selvaggia. Implicazioni politico-simboliche dello sradicamento, taglio e trasporto in città degli alberi nella Mesopotamia de…

2022

In Sumerian mythological literature, as in coeval Akkadian one, between the end of the 3rd and the beginning of the 2nd millennium, the ruler, foremost among them Gilgameš, on several occasions uproots and/or cuts down trees. These trees should be understood as elements of a wider ‘Wilderness’, with which they share a powerful and ambiguous ontological otherness compared to the city and, more generally, to the land of Sumer. The action of the king on the tree, like that of a farmer or gardener, with the consequent realization of ‘artefacts’, allows, through a cultural organization of the power of the tree, the renewal of the relationship, always subject to crisis, between the human communit…

The Windy clustered prize-collecting arc-routing problem

2011

This paper introduces the windy clustered prize-collecting arc-routing problem. It is an arc-routing problem where each demand edge is associated with a profit that is collected once if the edge is serviced, independent of the number of times the edge is traversed. It is further required that if a demand edge is serviced, then all the demand edges of its component are also serviced. A mathematical programming formulation is given and some polyhedral results including several facet-defining and valid inequalities are presented. The separation problem for the different families of inequalities is studied. Numerical results from computational experiments are analyzed. © 2011 INFORMS.

Determining noise and vibration exposure in conifer cross-cutting operations by using Li-Ion batteries and electric chainsaws

2018

In many activities, chainsaw users are exposed to the risk of injuries and several other hazard factors that may cause health problems. In fact, environmental and working conditions when using chainsaws result in workers&rsquo