Strain Monitoring of an Aluminium Joint with an Optical System

The stresses distribution can be easily determined in the cross-section of the elements but in a joint, the distribution of stresses is more complicated. Its complexity is also increased if stiffeners are added to the joint and if the connecting bolts are not positioned in a regular configuration. An aluminium cantilever with a two bolts connection is experimentally tested to determine the real capacity. Stiffeners reduce the stress intensity in the connection, but they are prone to instability problems if they are subjected to compression. In order to determine the real stress development in the stiffeners, the Digital Image Correlation (DIC) technique was used. This technique determines the strains in the loaded parts which then can be equivalated to the stress distribution. The paper presents the stress development in the compressed stiffeners of an aluminium joint considering also improvement solution for increasing the bending capacity by reducing the instability parameters.

Non-Linear Analysis of Asymmetric Structures

The study of multi-story building behaviour always depends on strength, durability, stiffness and adequacy of the regular configuration of the structures. Understanding the seismic behaviour of asymmetric structures is a challenging task, considering the aspect of irregularity (either in the plan or elevation) is generally known as asymmetric. Various researchers had studied the behaviour of this asymmetrical building by taking into considerations of different approaches such as plan configuration, vertical irregularity, mass and stiffness, in different methods of analysis. The irregular structures are less prone to the seismic forces, hence there is a need to study and specify some improvements in codal provisions for this type of asymmetrical structures. In the present study, we have considered a plan irregular structure (which replicates the Microsoft building at Hyderabad). The overall structural behaviour of asymmetrical building is investigated under different earthquake cases, such as with El-Centro, Loma and Uttarkashi database. Analysis of structure (using software program E-TABS V-17) for various earthquake intensities and checking for multiple criteria at every level for essential practice. The non-linear methods Time History analysis is carried over to find the structural behaviour. Keywords: multi-story building, plan irregularity, Time history analysis

Fensomea setacea, gen. & sp. nov. (Cladopyxidaceae, Dinophyceae), is neither gonyaulacoid nor peridinioid as inferred from morphological and molecular data

Dinophyte evolution is essentially inferred from the pattern of thecal plates, and two different labelling systems are used for the important subgroups Gonyaulacales and Peridiniales. The partiform hypotheca of cladopyxidoid dinophytes fits into the morphological concepts of neither group, although they are assigned to the Gonyaulacales. Here, we describe the thecate dinophyte Fensomea setacea, gen. & sp. nov., which has a cladopyxidoid tabulation. The cells displayed a Kofoidean plate formula APC, 3′, 4a, 7″, 7C, 6S, 6′′′, 2′′′′, and slender processes were randomly distributed over the echinate or baculate surface. In addition, we obtained rRNA sequences of F. setacea, gen. & sp. nov., but dinophytes that exhibit a partiform hypotheca did not show a close relationship to Gonyaulacales. Character evolution of thecate dinophytes may have progressed from the ancestral state of six postcingular plates, and two more or less symmetrically arranged antapical plates, towards patterns of only five postcingular plates (Peridiniales) or more asymmetrical configurations (Gonyaulacales). Based on our phylogenetic reconsiderations the contact between the posterior sulcal plate and the first postcingular plate, as well as the contact between an antapical plate and the distalmost postcingular plate, do not represent a rare, specialized gonyaulacoid plate configuration (i.e., the partiform hypotheca of cladopyxidoid dinophytes). Instead, these contacts correspond to the common and regular configuration of peridinioid (and other) dinophytes.

Correlation of the Madelung constant and I—M—I bonding angle with cohesive energy contributions in layered metal diiodides (MI2) with CdI2 (2H polytype) structure

This study uses theoretically methods to investigate, for metal diiodides MI2 (M = Mg, Ca, Mn, Fe, Cd, Pb) with CdI2 (2H polytype) structure, the mutual correlation between the structure-characterizing parameters (the flatness parameter of monolayers f, the Madelung constant A, and bonding angle I—M—I) and correlation of these parameters with contributions of the Coulomb and covalent energies to cohesive energy. The energy contributions to cohesive energy are determined with the use of empirical atomic potentials. It is demonstrated that the parameters f and A, and the bonding angle I—M—I are strictly correlated and increase in the same order: FeI2 < PbI2 < MnI2 < CdI2 < MgI2 < CaI2. It is found that with an increase of parameter A and bonding angle I—M—I the relative contribution of the Coulomb energy to cohesive energy increases, whereas the relative contribution of the covalent energy decreases. For a hypothetical MX 2 layered compound with the CdI2 (2H polytype) structure, composed of regular MX 6 octahedra (angle X—M—X = 90°), the flatness parameter and the Madelung constant are found to be f reg = 2.449 and A reg = 2.183, respectively. Correlation of the covalent energy with the type of distortion of MI6 octahedra (elongation or compression) with respect to regular configuration (angle I—M—I = 90°) is also analyzed.

Application of a topographic pedosequence in the Villány Hills for terroir characterization

Terroir refers to the geographical origin of wines. The landscape factors (topography, parent rock, soil, microbial life, climate, natural vegetation) are coupled with cultural factors (cultivation history and technology, cultivars and rootstock) and all together define a terroir. The physical factors can be well visualized by a slope profile developed into a pedosequence showing the regular configuration of the relevant physical factors for a wine district. In the present study the generalized topographic pedosequence (or catena) and GIS spatial model of the Villány Hills, a historical wine producing region, serves for the spatial representation and characterization of terroir types. A survey of properties of Cabernet Franc grape juice allowed the comparison of 10 vineyards in the Villány Wine District, Southwest Hungary. Five grape juice properties (FAN, NH3, YAN, density and glucose + fructose content) have been found to have a moderate linear relationship (0.5 < r2 < 0.7) with the Huglin Index (HI) and aspect. Aspect, when determined on the basis of angular distance from South (180°), showed a strong correlation (r2 > 0.7) with FAN, NH3, YAN, sugar and density and moderate correlation with primary amino nitrogen (PAN). HI showed a correlation with three nitrogen related parameters FAN, NH3, YAN, density and glucose + fructose content. Elevation and slope, however, did not correlate with any of the chemical properties.

A Single-Loop 7R Spatial Mechanism That Has Three Motion Modes With the Same Instantaneous DOF but Different Finite DOF

Multi-mode mechanisms, including kinematotropic mechanisms, are a class of reconfigurable mechanisms that can switch motion modes with the same or different DOF (degree-of-freedom). For most of the multi-mode mechanisms reported in the literature, the instantaneous (or differential) DOF and finite DOF in a motion mode are equal. In this paper, we will discuss the construction, reconfiguration analysis, and higher-order mobility analysis of a multi-mode single-loop 7R mechanism that has three motion modes with the same instantaneous DOF but different finite DOF. Firstly, the novel multi-mode single-loop 7R spatial mechanism is constructed by inserting one revolute (R) joint into a plane symmetric Bennett joint-based 6R mechanism for circular translation. The reconfiguration analysis is then carried out in the configuration space by solving a set of kinematic loop equations based on dual quaternions and the natural exponential function substitution using tools from algebraic geometry. The analysis shows that the multi-mode single-loop 7R spatial mechanism has three motion modes, including a 2-DOF planar 5R mode and two 1-DOF spatial 6R modes and can transit between each pair of motion modes through two transition configurations. The higher-order mobility analysis shows that the 7R mechanism has two-instantaneous DOF at a regular configuration of any motion mode and three instantaneous DOF in a transition configuration. The infinitesimal motions that are not tangential to finite motions are of second-order in transition configurations between 2-DOF motion mode 1 and 1-DOF motion modes 2 or 3 or first-order in transition configurations between 1-DOF motion modes 2 and 3.

The Phase II Murchison Widefield Array: Design overview

We describe the motivation and design details of the ‘Phase II’ upgrade of the Murchison Widefield Array radio telescope. The expansion doubles to 256 the number of antenna tiles deployed in the array. The new antenna tiles enhance the capabilities of the Murchison Widefield Array in several key science areas. Seventy-two of the new tiles are deployed in a regular configuration near the existing array core. These new tiles enhance the surface brightness sensitivity of the array and will improve the ability of the Murchison Widefield Array to estimate the slope of the Epoch of Reionisation power spectrum by a factor of ∼3.5. The remaining 56 tiles are deployed on long baselines, doubling the maximum baseline of the array and improving the arrayu, vcoverage. The improved imaging capabilities will provide an order of magnitude improvement in the noise floor of Murchison Widefield Array continuum images. The upgrade retains all of the features that have underpinned the Murchison Widefield Array’s success (large field of view, snapshot image quality, and pointing agility) and boosts the scientific potential with enhanced imaging capabilities and by enabling new calibration strategies.

Interactions between shape-persistent macromolecules as probed by AFM

Water-soluble shape-persistent cyclodextrin (CD) polymers with amino-functionalized end groups were prepared starting from diacetylene-modified cyclodextrin monomers by a combined Glaser coupling/click chemistry approach. Structural perfection of the neutral CD polymers and inclusion complex formation with ditopic and monotopic guest molecules were proven by MALDI–TOF and UV–vis measurements. Small-angle neutron and X-ray (SANS/SAXS) scattering experiments confirm the stiffness of the polymer chains with an apparent contour length of about 130 Å. Surface modification of planar silicon wafers as well as AFM tips was realized by covalent bound formation between the terminal amino groups of the CD polymer and a reactive isothiocyanate–silane monolayer. Atomic force measurements of CD polymer decorated surfaces show enhanced supramolecular interaction energies which can be attributed to multiple inclusion complexes based on the rigidity of the polymer backbone and the regular configuration of the CD moieties. Depending on the geometrical configuration of attachment anisotropic adhesion characteristics of the polymer system can be distinguished between a peeling and a shearing mechanism.

Optimal-Regularity for Serial Redundant Robots

A configuration of a mechanical linkage is defined as regular if there exists a subset of actuators with their corresponding Jacobian columns spans the gripper's velocity space. All other configurations are defined in the literature as singular configurations. Consider mechanisms with grippers' velocity space ℝm. We focus our attention on the case where m Jacobian columns of such mechanism span ℝm, while all the rest are linearly dependent. These are obviously an undesirable configuration, although formally they are defined as regular. We define an optimal-regular configuration as such that any subset of m actuators spans an m-dimensional velocity space. Since this densely constraints the work space, a more relaxed definition is needed. We therefore introduce the notion of k-singularity of a redundant mechanism which means that rigidifying k actuators will result in an optimal-regularity. We introduce an efficient algorithm to detect a k-singularity, give some examples for cases where m = 2, 3, and demonstrate our algorithm efficiency.