Identification and quantification of spinochromes in body compartments of <i>Echinometra mathaei</i>'s coloured types

Sea urchin pigmentation is mainly due to polyhydroxy-1,4-naphthoquinones called spinochromes. If their molecular structures are well known in test and spines of many species, their abundance and distribution in other body compartments remain unstudied. The aim of this study is to analyse the pigment composition in four body compartments (test/spines, digestive system, gonads and coelomic fluid) of four coloured types of the sea urchin Echinometra mathaei. Qualitative and quantitative measurements by mass spectrometry highlight the existence of 13 different pigments; among which are five isomers of known spinochromes as well as three potentially new ones. The composition comparison shows the largest spinochrome diversity in ‘test/spines’ body compartments. The spinochrome concentrations vary from 48 to 1279 mg kg−1 of dried body compartment. It is the highest in the digestive system, although it is also important in the organic fraction of the ‘test/spines’ body compartment. This observation may be explained by higher exposures of some body compartments to external environments and by the protective role fulfilled by spinochromes against microorganisms, ultraviolet radiation and reactive oxygen species. The ‘black’ type—the most common coloured type in coral reefs—has the highest concentration of spinochromes indicating their importance in Echinoids' fitness by acting as a protective agent

Tailoring the pressure-drop in multi-layered open-cell porous inconel structures

This study investigates the pressure-drop behaviour associated with airflow through bulk and structurally tailored multi-layered, open-cell porous Inconel structures over a wide airflow velocity range (0–50 m s-1). The effect of airflow velocity on the pressure-drop behaviour as a function of the sample thickness is presented and related to the flow behaviour corresponding to the relevant flow regimes (Darcy, Forchheimer, Turbulent and Postturbulent). Entrance effects are highlighted as a source of the pressure-drop increase for porous structures with air gaps, regardless of their sizes, as long as they are larger than those generated by loosely-stacked structures. The pressure-drops for gapped porous structures and the mathematical-summation of the pressure drop for the corresponding individual components, were in very good agreement, at lower airflow velocities. The potential for mass-efficient porous structures, providing a high pressure drop, was demonstrated using multiple thin porous laminates separated by air gaps

Experimental investigation of pressure-drop characteristics across multi-layer porous metal structures

This study investigates the effect of airflow (in the range of 0–70 m s-1) on the pressure-drop characteristics for a novel multi-layered, nickel-based porous metal, as a function of thickness (affected by sectioning) and density (affected by compression). In addition to generating unique data for these materials, the study highlights the need for precise pinpointing of the different flow regimes (Darcy, Forchheimer and Turbulent) in order to enable accurate determination of the permeability (K) and form drag coefficient (C) defined by the Forchheimer equation and to understand the complex dependence of length-normalised pressure drop on sample thickness

All-conjugated cationic copolythiophene "rod-rod" block copolyelectrolytes: Synthesis, optical properties and solvent-dependent assembly

The optical and thermal properties and solvent-dependent assembly of all-conjugated cationic copolythiophene block copolyelectrolytes are investigated.</p

Binding energies of ground and isomeric states in neutron-rich ruthenium isotopes: measurements at JYFLTRAP and comparison to theory

We report on precision mass measurements of $^{113,115,117}$Ru performed with the JYFLTRAP double Penning trap mass spectrometer at the Accelerator Laboratory of University of Jyv\"askyl\"a. The phase-imaging ion-cyclotron-resonance technique was used to resolve the ground and isomeric states in $^{113,115}$Ru and enabled for the first time a measurement of the isomer excitation energies, $E_x(^{113}$Ru$^{m})=100.5(8)$ keV and $E_x(^{115}$Ru$^{m})=129(5)$ keV. The ground state of $^{117}$Ru was measured using the time-of-flight ion-cyclotron-resonance technique. The new mass-excess value for $^{117}$Ru is around 36 keV lower and 7 times more precise than the previous literature value. With the more precise ground-state mass values, the evolution of the two-neutron separation energies is further constrained and a similar trend as predicted by the BSkG1 model is obtained up to the neutron number $N=71$.Comment: 12 pages, 9 figures, submitted to Physical Review

Finite difference calculations of permeability in large domains in a wide porosity range.

Determining effective hydraulic, thermal, mechanical and electrical properties of porous materials by means of classical physical experiments is often time-consuming and expensive. Thus, accurate numerical calculations of material properties are of increasing interest in geophysical, manufacturing, bio-mechanical and environmental applications, among other fields. Characteristic material properties (e.g. intrinsic permeability, thermal conductivity and elastic moduli) depend on morphological details on the porescale such as shape and size of pores and pore throats or cracks. To obtain reliable predictions of these properties it is necessary to perform numerical analyses of sufficiently large unit cells. Such representative volume elements require optimized numerical simulation techniques. Current state-of-the-art simulation tools to calculate effective permeabilities of porous materials are based on various methods, e.g. lattice Boltzmann, finite volumes or explicit jump Stokes methods. All approaches still have limitations in the maximum size of the simulation domain. In response to these deficits of the well-established methods we propose an efficient and reliable numerical method which allows to calculate intrinsic permeabilities directly from voxel-based data obtained from 3D imaging techniques like X-ray microtomography. We present a modelling framework based on a parallel finite differences solver, allowing the calculation of large domains with relative low computing requirements (i.e. desktop computers). The presented method is validated in a diverse selection of materials, obtaining accurate results for a large range of porosities, wider than the ranges previously reported. Ongoing work includes the estimation of other effective properties of porous media

β-delayed γ-proton decay in 56Zn: analysis of the charged-particle spectrum

A study of the beta decay of the proton-rich T-z = 2 nucleus Zn-56 has been reported in a recent publication. A rare and exotic decay mode, beta-delayed gamma-proton decay, has been observed there for the first time in the fp shell. Here, we expand on some of the details of the data analysis, focussing on the charged particle spectrum