Search results for "THINNING"

Design of sheet stamping operations to control springback and thinning: a multi-objective stochastic optimization approach

2010

Abstract The aim of this paper is to develop a design tool for stamping processes, which is able to deal with the scattering of the final part quality due to the inner variability of such operations. Such variability is one of the main drawbacks for a robust process design. It results in a scattering of the most significant process results and depends on several parameters. The so called noise factors greatly influence final result variability, which often means rejecting parts and anyway achieving final properties different from the specified ones. The process investigated in the paper is an S-shaped U-channel stamping operation carried out on a lightweight aluminum alloy of automotive int…

A Comparative Analysis of Different Robust Design Approaches in Sheet Stamping Operations

2011

A crucial issue in sheet stamping optimization problems is related to the process robustness improvement: critical scattering in the investigated performances arises due to some noise variables influence, often evolving up design failure itself. In fact, strong variations in the final stamped part or fluctuations of strain distribution may lead to an uncontrolled process design. Such variability cannot be controlled but anyway it is possible to develop proper design tools able to identify robust process calibrations above which the noises variations effects are admissible. In this paper, a multi‐objective optimization problem was analyzed, with the aim to minimize both excessive thinning an…

Discontinuous thinning in active microrheology of soft complex matter

2016

Employing theory and numerical simulations, we demonstrate discontinuous force thinning due to the driven motion of an external probe in a host medium. We consider two cases: an ideal structureless medium (modeling ultrasoft materials such as polymer melts) and a dilute bath of interacting repulsive particles. When the driving of the probe exceeds a critical force, the microviscosity of the medium drops abruptly by about an order of magnitude. This phenomenon occurs for strong attractive interactions between a large probe and a sufficiently dense host medium.

Improvement in yield and fruit size and quality of the main Italian table olive cultivar 'Nocellara del Belice'

2014

Olive (Olea europaea L.) shows alternate bearing, with unreliable cropping patterns and inconsistent fruit size and quality every year. In many countries, thinning with naphthaleneacetic acid (NAA) is used to minimise alternate bearing behavior in olives. However, in Italy, growers are reluctant to employ this practice and no detailed knowledge is available for specific cultivars. We evaluated the effects of spraying NAA on various dates on the productive and vegetative characteristics of the main Italian table olive cultivar'Nocellara del Belice'. Trunk cross-sectional area, fruit set, fruit drop, fruit size, pit size, yield per tree, crop density and flesh to pit ratio were analysed. The …

GLOBAL AND REGIONAL CORTICAL THINNING IN FIRST-EPISODE SCHIZOPHRENIA PATIENTS: RELATIONSHIPS WITH CLINICAL AND COGNITIVE FEATURES

2010

Dynamics, alterations, and consequences of minimally invasive intraocular pressure elevation in rats.

2014

PURPOSE: An important, yet not exclusive, aspect of primary open angle glaucoma is elevated intraocular pressure (IOP) profiles within fluctuations and pressure peaks. The study aimed at establishing minimally invasive methods for recurrent IOP elevation in rats to investigate the impact of IOP dynamics and pathomorphologic retinal alterations during and after IOP elevation. METHODS: Intraocular pressure was elevated unilaterally in Long Evans rats to a level of ≈35 mm Hg for 1 hour in a total of 30 manipulations within 6 weeks, by using two methods: (1) suction-cup oculopression and (2) loop-adjusted oculopression. Retinal thickness (RT) was measured via optical coherence tomography (OCT),…

Rheological and Flocculation Analysis of Microfibrillated Cellulose Suspension Using Optical Coherence Tomography

2018

A sub-micron resolution optical coherence tomography device was used together with a pipe rheometer to analyze the rheology and flocculation dynamics of a 0.5% microfibrillated cellulose (MFC) suspension. The bulk behavior of the MFC suspension showed typical shear thinning (power-law) behavior. This was reflected in a monotonously decreasing floc size when the shear stress exceeded the yield stress of the suspension. The quantitative viscous behavior of the MFC suspension changed abruptly at the wall shear stress of 10 Pa, which was reflected in a simultaneous abrupt drop of the floc size. The flocs were strongly elongated with low shear stresses. With the highest shear stresses, the flocs…

Tectono-stratigraphic modelling of the North Sicily continental margin (southern Tyrrhenian Sea).

2004

A two-dimensional numerical modelling that simulate the kinematic and thermal response of the lithosphere to thinning was used for the quantitative reconstruction of the late Neogene to Recent times tectonic and stratigraphic evolution of the North Sicily continental margin (southern Tyrrhenian Sea). The numerical study of the evolution of the North Sicily margin builds on the crustal image and kinematic interpretation of the margin obtained by Pepe et al. [Tectonics 19 (2000) 241] on the basis of seismic data and gravity modelling. Tectonic modeling indicate that different segments of the margin were undergoing different vertical movements, which are mainly expression of the rifting and th…

EFFECTS OF LIGHT REDUCTION AT BLOOM ON FRUITS SET IN BLACK MAGIC TABLE GRAPES CV IN EARLY AND LATE PRODUCTION CICLES

2013

A shading experiment in ‘Black Magic’ cv was conducted in Sicily to test a new thinning method, aiming to reduce the no. berries/cluster, maximising quality and value of the production. A reduction of intercepted light was imposed at the 65 stage of the BBCH scale (50% cap fall) for 12 days. The soilless greenhouse conditions allowed two growing cycles occurring under different climate conditions, an early (end of March flowering) and a late production cycle (beginning of August flowering). During the shade treatment, net photosynthetic rate was significantly reduced by 82% and 96% in the late and early production cycles, respectively. The sum of flowers and berries dropped in the untreated…

Effetti dei diradamenti sulle caratteristiche ecologiche e selvicolturali dei rimboschimenti di pino d’Aleppo nei Monti Sicani (Sicilia occidentale)

2014

I rimboschimenti di conifere mediterranee sono, in Sicilia, una delle tipologie forestali più rappresentative, sia per la superficie che occupano sia per l’eterogeneità ambientale dei contesti territoriali dove sono stati realizzati. Scopo principale della presente indagine è stato quello di effettuare una valutazione degli impatti dei diradamenti sulle caratteristiche ecologiche e selvicolturali dei rimboschimenti di pino d’Aleppo. L’indagine è stata condotta in tre differenti siti localizzati nell’area dei Monti Sicani caratterizzati dalla stessa tipologia forestale (Pineta a pino d’Aleppo) e da simili caratteristiche stazionali. Inoltre, tutti e tre i siti sono stati interessati da inter…