Search results for "Geometry"

Standardization of Methods for Characterizing the Surface Geometry of Solids

2003

Since a comprehensive survey published in 1999 [1] much work was done in standardizing measuring methods to characterize the surface geometry of dispersed and/or porous solids and to certify reference materials. The present paper is an extension of a short communication [2]. It gives a survey on existing standards and reports on new drafts and proposals.

Applying Experimental Research Management to a Technological Process using Taguchi's Method

2018

Abstract The surface quality is dependent on certain cutting process parameters that can vary, causing variations on the surface roughness. The main subject of this paper focuses on the experimental research management applied to a technological process whose final purpose was to determine an equation of the surface roughness depending on the process parameters, obtained by the Al7136 end milling process. The research method used in this paper is the Taguchi's method. According to the research management steps, in order to perform the experimental determination of the surface roughness, an experimental stand used to determine the objective function was presented. The surface roughness equat…

Controlling the Interactions between Soft Colloids via Surface Adsorption

2013

By employing monomer-resolved computer simulations and analytical considerations based on polymer scaling theory, we analyze the conformations and interactions of multiarm star polymers strongly adsorbed on a smooth, two-dimensional plane. We find a stronger stretching of the arms as well as a stronger repulsive, effective interaction than in the three dimensional case. In particular, the star size scales with the number of arms $f$ as $\sim f^{1/4}$ and the effective interaction as $\sim f^{2}$, as opposed to $\sim f^{1/5}$ and $\sim f^{3/2}$, respectively, in three dimensions. Our results demonstrate the dramatic effect that geometric confinement can have on the effective interactions and…

Non-Arrhenius Behavior of Surface Diffusion Near a Phase Transition Boundary

1997

We study the non-Arrhenius behavior of surface diffusion near the second-order phase transition boundary of an adsorbate layer. In contrast to expectations based on macroscopic thermodynamic effects, we show that this behavior can be related to the average microscopic jump rate which in turn is determined by the waiting-time distribution W(t) of single-particle jumps at short times. At long times, W(t) yields a barrier that corresponds to the rate-limiting step in diffusion. The microscopic information in W(t) should be accessible by STM measurements.

2021

Abstract We extend the classical Carathéodory extension theorem to quasiconformal Jordan domains (Y, dY ). We say that a metric space (Y, dY ) is a quasiconformal Jordan domain if the completion ̄Y of (Y, dY ) has finite Hausdorff 2-measure, the boundary ∂Y = ̄Y \ Y is homeomorphic to 𝕊1, and there exists a homeomorphism ϕ: 𝔻 →(Y, dY ) that is quasiconformal in the geometric sense. We show that ϕ has a continuous, monotone, and surjective extension Φ: 𝔻 ̄ → Y ̄. This result is best possible in this generality. In addition, we find a necessary and sufficient condition for Φ to be a quasiconformal homeomorphism. We provide sufficient conditions for the restriction of Φ to 𝕊1 being a quasi…

Soil Erosion as an Environmental Concern ... for Everyone?

2020

Nowadays, the scientific community is aware of the negative environmental impacts of soil erosion on ecosystem services. Soil erosion is one of the most important causes of land degradation because of its immediate influence of the most fertile topsoil parts. It is well-known that questions related to who, what, why, where and when soil erosion causes negative impacts must be considered by stakeholders and policymakers. However, why do the Sustainable Development Goals tell anything about soil erosion? In this keynote, we will try to show the importance to develop tools which can be used to assess soil erosion to obtain convincing results for stakeholders and policymakers. According to this…

About Objective 3-D Analysis of Airway Geometry in Computerized Tomography

2008

The technology of multislice X-ray computed tomography (MSCT) provides volume data sets with approximately isotropic resolution, which permits a noninvasive 3-D measurement and quantification of airway geometry. In different diseases, like emphysema, chronic obstructive pulmonary disease (COPD), or cystic fribrosis, changes in lung parenchyma are associated with an increase in airway wall thickness. In this paper, we describe an objective measuring method of the airway geometry in the 3-D space. The limited spatial resolution of clinical CT scanners in comparison to thin structures like airway walls causes difficulties in the measurement of the density and the thickness of these structures.…

The European Flag According to Paolo Fabbri

2021

Too often we consider symbols in our cultures to be indivisible monoliths that can only be interpreted through the connotations they take on over time. This is due, on one hand, to their compact nature, the correspondence between the planes of expression and content that make them appear solid, impossible to break down. However, it is also true that in the majority of cases we inherit ready-made symbols that seem to have been born with their current shape, with no hint as to the processes that have made them this way. As a rule, there are so many, varied meanings of the word “symbol” that, in the absence of a clear, consensual hypothesis on what a symbol is, they can be difficult to read. A…

A Dominant Global Translation Strategy in Thai Translated Novels: The Translations of Religious Markers in Dan Brown’s Thriller Novels

2020

When translation is considered as an integral part of larger social systems (Even-Zohar 1990), the ways in which translations are produced to serve readers’ specificity could be affected. This paper examines whether there is a preference for a specific global translation strategy due to a readership that is specialized in terms of education level. Adopting Venuti’s (1995/2008) division of global translation strategies into exoticizing and domesticating translation, it examines the frequency of local translation strategies, which are part of a global translation strategy, used in translating English-Thai religious markers in Dan Brown’s Angels and Demons, The Da Vinci Code, The Lost Symbol, …

The S-kernel: A measure of symmetry of objects

2007

In this paper we introduce a new symmetry feature named ''symmetry kernel'' (SK) to support a measure of symmetry. Given any symmetry transform S, SK of a pattern P is the maximal included symmetric sub-set of P for all directions and shifts. We provide a first algorithm to exhibit this kernel where the centre of symmetry is assumed to be the centre of mass. Then we prove that, in any direction, the optimal axis corresponds to the maximal correlation of a pattern with its symmetric version. That leads to a second algorithm. The associated symmetry measure is a modified difference between the respective surfaces of a pattern and its kernel. A series of experiments supports the actual algorit…