Search results for "Cutting"
showing 10 items of 164 documents
TECHNOLOGICAL PERSPECTIVES REGARDING THE APPLICATION OF THE CONTACT BREAKING ELECTRICAL DISCHARGE MACHINING PROCESS USING AS ELECTRODE-TOOL - METAL B…
2020
The scientific paper presents the most important aspects of theoretical and practical nature regarding the possibilities of processing metallic materials using the contact breaking electrical discharge machining with transfer object-metal band. The exposed research is based on the experience gained over the years by a team of Romanian researchers and university professors who managed to patent a metal material cutting plant using the process of contact breaking electrical discharge machining with transfer object-metal band. The scientific paper presents a radiography of some studies and research carried out over the years in the previous field presented.
Use of Battery- vs. Petrol-Powered Chainsaws in Forestry: Comparing Performances on Cutting Time
2022
The use of battery tools is very common in many fields of work. In fact, the electric engine and batteries have several advantages over traditional endothermic engines, including low emissions, in terms of pollutants, vibration and noise. In this context, the chainsaw market started producing electric models powered by batteries. These machines can be useful in forestry, but information on their performance is scarce. The aim of this work was to compare the performance, in terms of cutting times, of three Stihl chainsaw models: the MS 220C-B (battery powered), and the MS 201 C-M and MS 261 C-M (both petrol powered). The study was carried out on five different wood species, also taking into …
A synthesis of multi-taxa management experiments to guide forest biodiversity conservation in Europe
2023
Most European forests are used for timber production. Given the limited extent of unmanaged (and especially primary) forests, it is essential to include commercial forests in the conservation of forest biodiversity. In order to develop ecologically sustainable forest management practices, it is important to understand the management impacts on forest-dwelling organisms. Experiments allow testing the effects of alternative management strategies, and monitoring of multiple taxa informs us on the response range across forest-dwelling organisms. To provide a representative picture of the currently available information, metadata on 28 multi-taxa forest management experiments were collected from…
Browsing hinders the regeneration of broadleaved trees in uneven-aged forest management in southern Finland
2020
Uneven-aged forest management has attained increasing popularity. It may benefit biodiversity, buffer against pests and abiotic damages, decrease runoff from clearcuts and improve recreational values. We studied how gap cuttings and single-tree selection cuttings influence browsing damage in spruce-dominated forests in south-central Finland. Overall, browsing damage was especially frequent in aspen and rowan, but also in birch. The larger the basal area left in harvesting, the lower the browsing pressure on birch and rowan; neither the harvesting method nor the seedling density had an independent effect on browsing damage. Although larger tree retention levels may reduce browsing damage, th…
Research on conversion of Carrizo citrange [C. sinensis (L.) Osb. × P. trifoliata (L.) Raf.] synthetic seeds.
2008
MATHEMATICAL MODELLING OF SURFACE ROUGHNESS FOR EVALUATING THE EFFECTS OF WEDM CUTTING PARAMETERS
2020
Wire Electrical Discharge Machining is a cutting method used for obtaining parts with complex geometries or for cutting hard metals. In machining processes, it is necessary to obtain the desired surface quality in order to produce parts providing the required functioning. The surface quality also defines some mechanical properties of the product, such as wear resistance. Being such a considerable quality, surface quality is influenced by various parameters. It will be costly and time consuming to acquire the knowledge of appropriate cutting parameters. Unconventional technologies have not been sufficiently studied so far to provide such details. So, this рарer ѕeekѕ to emрhаѕіze the іmрortа…
Factores de rendimiento en el desplazamiento del tenista influenciados por el calzado. (Performance factors on tennis player displacements influenced…
2009
Los desplazamientos laterales son de gran importancia en el tenis. Sin embargo, no ha sido publicado ningun estudio sobre el efecto del calzado sobre el rendimiento en este tipo de movimientos. En el estudio participaron 5 jugadores habituales de tenis y se analizaron 10 calzados comerciales de tenis. El movimiento estudiado consistio en un desplazamiento lateral con parada y cambio de sentido, registrandose las fuerzas mediante una plataforma dinamometrica Dinascan-IBV y grabandose el movimiento con dos camaras de video S-VHS Panasonic WV-BL600. Los resultados de los ANOVAs realizados mostraron que algunas de las variables analizadas eran dependientes del calzado (p < 0.05). De estas, dest…
Nesting Problems : Exact and Heuristic Algorithms
2013
Nesting problems are two-dimensional cutting and packing problems involving irregular shapes. This thesis is focused on real applications on Nesting problems such as the garment industry or the glass cutting. The aim is to study different mathematical methodologies to obtain good lower bounds by exact procedures and upper bounds by heuristic algorithms. The core of the thesis is a mathematical model, a Mixed Integer Programming model, which is adapted in each one of the parts of the thesis. This study has three main parts: first, an exact algorithm for Nesting problems when rotation for the pieces is not allowed; second, an Iterated Greedy algorithm to deal with more complex Nesting problem…
Height as a predictor of Parkinson's disease: a case-control study.
2005
Diversifying crop rotations with temporary grasslands: potentials for weed management and farmland biodiversity
2010
Fruchtfolgen können dazu dienen, die kontinuierliche Selektion von Unkrautarten zu verhindern, die an eine bestimmte Kultur angepasst sind. Dies könnte dem Unkrautmanagement, der Einsparung von Herbiziden, und der Biodiversität dienen. Heutige, sehr einfache Furchtfolgen könnten durch mehrjährige Futterkulturen diversifiziert werden. Die Einflüsse solcher mehrjähriger Kulturen auf Unkräuter wurden in vier Ansätzen untersucht : 1) Vegetationsaufnahmen auf 632 Feldern in Westfrankreich zeigten, dass die Unkrautzusammensetzung zwischen mehrjährigen Futterkulturen und einjährigen Kulturen stark variiert. Der Vergleich von Feldern vor, während und nach mehrjährigen Futterkulturen legte nahe, das…