Two-Dimensional Ordering of Coumarin at the Indium Amalgam–Electrolyte Interface

The two-dimensional condensation of coumarin was investigated at the indium amalgam-aqueous solution interface by capacitance-potential and charge-time measurements. Two distinct adsorption states were found for saturated coumarin solutions in 0.5 M NaF at 10 °C. Similar to the adsorption behavior on mercury, coumarin molecules can form a monolayer presenting the characteristics of a two-dimensional condensed layer. An increase of the indium content of the amalgam leads to an extension of the stability range of the condensed monolayer at most negative potentials. The shift of the transition potential parallels the variation of the pzc of the amalgams. The kinetics of condensation of coumarin were investigated by the potential step technique at a 50% In-Hg electrode. Mononuclear transients leading to the condensed film are observed in a wide range of the overvoltage. A comparison of the data obtained at the amalgam and mercury electrodes shows that the growth rate is independent of the nature of the electrode and that the detection of a single event takes place at lower supersaturations at the amalgam electrode.     

An Empirical Study of Individual Competencies in Distribution Centres to Enable Continuous Innovation

Individual competencies are the complex combination of knowledge, skills and abilities demonstrated by employees that are critical to the effective and efficient functioning of the organization. As firms pursue strategies and commitment to continuously innovate, the major resource to enable this process lies in the people within the organization. Logistics firms in developed economies such as Singapore and Australia are embarking on these strategies to remain competitive. The key objective of this paper is to investigate the competencies that are inherent in employees of distribution centres as part of the logistic function that are rapidly growing and innovating. The study adopts an iterative process of data collection by conducting ten case studies in Singapore and Australia and interviews with senior managers. The findings show several competencies apparent in employees of the firms studied. These underpinned collective behaviours and organizational capabilities needed for continuous innovation. This study provides important lessons for managers in logistics organizations in Australia and Singapore and demonstrates how differing extents of competencies and behaviours of employees can impact on the operations of firms and their capacities to innovate.     

Structure and water—oil emulsifying properties of asphaltenes

Alphaltenes were selected on the basis of their capacity to form water—oil emulsions. They were characterized by electron microscopy, surface group analysis, g.p.c. and low-angle X-ray scattering. It appears that the high stability of water-oil emulsions is related to the ‘structuring’ capacity of asphaltenes at the water-oil interface. Some asphaltenes are able to form regularly stacked layers, resembling the behaviour of surfactant liquid crystals.     

Influence of Oxygen Vacancies on the Electronic Structure of Yttrium Oxide

The influence of oxygen vacancies on the electronic structure of yttrium oxide was investigated both experimentally and theoretically. By means of X-ray absorption spectroscopy, at the yttrium K and L ₁₁ edges and at the oxygen K edge, information on the local densities of states of various orbital symmetries, around each type of atom, was obained. The total density of states in the valence band was studied using X-ray photoelectron spectroscopy. Experimental results were compared with those obtained on stoichiometric yttria. The evolution of the densities of states is well reproduced by self-consistent, semiempirical tight-binding calculations applied to clusters of increasing size, in which oxygen vacancies are introduced. The charge transfer between oxygen and yttrium is modified, as experimentally observed from the study of the O KLL Auger line shape. The decrease of the local atomic charge on oxygen is theoretically confirmed by the tight-binding calculations, showing a tendency toward a more covalent bond in nonstoichiometric yttria.     

Correction to: Obstacles and opportunities for reducing dwelling size to shrink the environmental footprint of housing: Tenants’ residential preferences and housing choice

Journal of Housing and the Built Environment -     

Spectroscopic Investigation of the Coloration and Fabrication Conditions of Medieval Blue Glasses

Potash‐ and soda‐lime‐stained glasses from the 12th–13th centuries, blue‐colored by cobalt, have been investigated by Mn, Fe, and Cu K‐edge X‐ray and optical absorption spectroscopies in order to determine the oxidation state of these elements and their impact on the blue color. Remelting these historical glasses in air at 1200°C, the estimated temperature of medieval furnaces, revealed that these four glasses are more reduced before remelting. This favors Mn as weakly absorbing Mn²⁺, Fe as Fe²⁺ and Cu as colorless Cu⁺. Therefore Fe²⁺ is the second blue chromophore and copper was not intentionally used by glassmakers to obtain a blue color. A colorimetric analysis indicates that these specific melting conditions have a limited effect on the blue color of these glasses. Based on the spectroscopic determination of the redox state of Fe, Mn, and Cu, we estimate the oxygen partial pressure in medieval furnaces to be 10^?7–10^?9 and 10^?5 bar for the potash‐ and soda‐lime samples, respectively. The comparison with previous results enables to prove the evolution of furnace technology over centuries.     

Effect of production systems on phenolic composition and oxygen radical absorbance capacity of ‘Orléans’ strawberry

The effect of two production systems, plastic mulch (PM) and plastic mulch with row covers (PMRC) versus the commonly used matted-row system (MRS) was evaluated on phenolic composition and oxygen radical absorbance capacity (ORAC) of ‘Orléans’ strawberry at three different harvest times during growing season. Six major groups of phenolic compounds, including anthocyanins, hydroxycinnamic acids, kaempferol, flavonols, ellagic and benzoic acids, were assessed in strawberry. Production systems significantly affect the antioxidant capacity and phenolic content of strawberry. PMRC generally enhanced the phenolic content and total antioxidant capacity compared to MRS and PM, but the effects varied during the harvest season. Therefore, PMRC could be a recommended production system to improve the nutraceutical value of strawberry fruits especially in cooler climates.