Search results for "Cutting"
showing 10 items of 164 documents
A computational study of several heuristics for the DRPP
1995
The problem of designing a route of minimum length for a postman that starts and finishes at his office and has to deliver the mail along a set of streets in a city is known as the Rural Postman Problem. When the postman has to obey the directions of the streets, we have the directed version of this problem. Finding an exact solution, in the general case, is intractably difficult. Hence, we have implemented three heuristic algorithms for approximately solving this problem and a procedure for obtaining a lower bound to the optimal length. Also, we present numerical experimentations based on a collection of random instances with up to 30 connected components, 240 vertices and 801 arcs. A lowe…
The effects of benzyladenine and meta-Topolin on in vitro sprouting and regrowth after encapsulation of C35 citrange [Citrus sinensis (L.) Osb. × Pon…
2016
C35, a hybrid of ‘Ruby Blood’ sweet orange and trifoliate orange, is a promising Citrus rootstock, mainly due to its resistance to Citrus Tristeza Virus (CTV), one of the most serious pathology affecting citriculture. The use of resistant rootstocks, such as citranges, is an efficient tool to fight this plant disease. This implies a continuous increasing demand of resistant rootstocks, in order to carry out the turnover of sour orange, still the most used Citrus rootstock in Italy. Micropropagation, can provide innovative solutions to obtain, in a short time and in a small space, a number of plants higher than traditional propagation. Micropropagation efficiency is also affected by the cult…
Transplantation assessment of degraded Posidonia oceanica habitats: site selection and long-term monitoring
2014
A model developed for Zostera marina was adapted and used to select suitable areas for Posidonia oceanica transplantation in the Gulf of Palermo, where recent rehabilitation programmes have reduced human pressure. This model consists of three steps: (1) habitat selection, by calculation of the Preliminary Transplant Suitability Index (PTSI); (2) field assessments and test-transplanting, to evaluate the site suitability and to estimate the effects of tearing on transplant units (about 50%); (3) identification of suitable restoration sites, by calculation of the Transplant Suitability Index (TSI). A new parameter was added to the literature model: the number of grids detached, which is linked…
In-process tool-failure detection by means of AR models
1997
The present paper proposes a cutting tool breaking and chipping detection system for continuous and interrupted cutting, based on the analysis of the cutting force componentsFx andFy. A multifactorial experimental design has been carried out, to take account of the variability of the force signal. An adaptive signal processing algorithm is proposed, which detects catastrophic failure when at least one component deviates outside an estimated oscillation band for a time duration longer than a prefixed interval. The algorithm has been implemented on a four-microprocessor transputer board. Several tests confirmed the validity of the approach for detecting breaking and chipping phenomena in a fe…
Green and Integrated Wearable Electrochemical Sensor for Chloride Detection in Sweat
2022
Wearable sensors for sweat biomarkers can provide facile analyte capability and monitoring for several diseases. In this work, a green wearable sensor for sweat absorption and chloride sensing is presented. In order to produce a sustainable device, polylactic acid (PLA) was used for both the substrate and the sweat absorption pad fabrication. The sensor material for chloride detection consisted of silver-based reference, working, and counter electrodes obtained from upcycled compact discs. The PLA substrates were prepared by thermal bonding of PLA sheets obtained via a flat die extruder, prototyped in single functional layers via CO2 laser cutting, and bonded via hot-press. The effect of co…
Responses of Young Peach Trees to Root Confinement
1994
Rooted cuttings of Nemaguard peach [Prunus persica (L.) Batsch.] were grown in 0.18-, 0.36-, 0.90-, and 2.40-liter containers for 16 weeks to study the influence of root confinement on growth, gas exchange, water uptake, and leaf carbohydrate and nutrient content. An automatic nutrient-solution dispensing system was used to ensure uniform fertility among treatments and to prevent drought stress. Leaf area and stem length were reduced by root confinement 6 to 7 weeks after transplanting, and differences among treatments increased throughout the experiment. Final tree dry weights were reduced by 51% over a 13-fold reduction in rooting volume, but dry weight partitioning was largely unaffected…
Use of carbon dioxide enrichment to obtain adult morphology of grapevinein vitro
1993
A procedure has been developed forin vitro propagation ofVitis vinifera ‘Pinot noir’ from lateral-bud cuttings under high CO2 concentration (1200 µmol mol−1). Because of inhibition of rooting by CO2, this procedure requires a rooting pre-culture of explants on medium with sucrose before the CO2-enriched culture on sucrose-free medium. Shoot growth was enhanced by CO2 enrichment as a result of both a higher rate of leaf production and greater internode elongation. Leaf expansion and tendril growth were promoted and better rooting was obtained. The more significant effect of CO2 enrichment was to promote adult morphology with, in particular, the tendril pattern. Thus, for the first time, grap…
Considerations on Cutting Regime Influence of NC Laser Cutting Machine Tool on Processed Surface Quality
2015
This paper presents the study of the influence of cutting parameters on surface quality in laser cutting of metallic materials. In this paper, it is shown which of the cutting parameters have the greatest influence on the quality of the processed surfaces by measuring various roughness parameters. After the experimental research was carried out a ranking of the factors of influence on the response functions was made, also graphs of dependency to various parameters of roughness were made.
A critical analysis on the friction modelling in orthogonal machining
2007
Abstract Despite the development of high performance finite element-based codes, the simulation of machining still represents a very hard task due to the geometric complexity of the real chip-tool systems and the high cutting speed that requires very long simulation times. For these reasons, many aspects related to machining are not very clear and so easy to simulate. In this paper a rigorous investigation on the role played by the implemented friction model within a 2D simulation of orthogonal cutting was carried out, taking into account different models proposed by the researchers in the last years. The main simulation results were compared with experimental measurements in order to verif…
Improving the Performance of Steel Machining Processes through Cutting by Vibration Control
2021
Machining processes through cutting are accompanied by dynamic phenomena that influence the quality of the processed surfaces. Thus, this research aimed to design, make, and use a tool with optimal functional geometry, which allowed a reduction of the dynamic phenomena that occur in the cutting process. In order to carry out the research, the process of cutting by front turning with transversal advance was taken into account. Additionally, semi-finished products with a diameter of Ø = 150 mm made of C45 steel were chosen for processing (1.0503). The manufacturing processes were performed with the help of two tools: a cutting tool, the classic construction version, and another that was the i…