Chemical Characterization of Bromine Oxidized Potato Starch

Potato starch was oxidized with a neutral aqueous bromine solution at seven different levels of molar ratios of bromine/starch (1/40–5/1). The molecular weight distribution of the products obtained was analysed by gel permeation chromatography on two different agarose gels, Sepharose CL-2B and Superose 6. A gradually increased fragmentation of the molecules with increased oxidation level was noticed. Some of the modified samples were debranched and the products obtained were analysed by gel permeation chromatography. For comparison amylose and waxy maize starch were also treated at the 1/20 and 1/5 molar ratios. The results indicate that the amylose is more easily degraded to small fragments than amylopectin during the oxidation process. An enzymatic starch analysis method was applied on the oxidized samples. This method was found suitable for estimating the total content of introduced keto and carboxylic groups into the modified product.     

Phenolic acids in fresh and retted jute plants (Corchorus capsularis and Corchorus olitorius)

Fresh and retted bark and stem of the Corchorus capsularis and Corchorus olitorius species of jute plant were analysed for their phenolic acid contents. Free and bound phenolic acids were identified and quantitatively determined by means of HPLC. Ferulic and p-coumaric acids were the main components, whereas p-hydroxybenzoic, protocatechuic, vanillic and caffeic acids were present in varying amounts in different jute fractions. The stem contained more free phenolic acids than the bark, and the differences were very pronounced in the retted samples. On the other hand, the bark from all four samples contained more extractable ester-bound phenolic acid than the stem. The stem of fresh C. olitorius and retted bark (fibre) of both species contained more non-extractable bound phenolic acids, in particular p-coumaric acid, than the other fractions.     

On the discrete and continuous time infinite-dimensional algebraic Riccati equations

The standard state space solution of the finite-dimensional continuous time quadratic cost minimization problem has a straightforward extension to infinite-dimensional problems with bounded or moderately unbounded control and observation operators. However, if these operators are allowed to be sufficiently unbounded, then a strange change takes place in one of the coefficients of the algebraic Riccati equation, and the continuous time Riccati equation begins to resemble the discrete time Riccati equation. To explain why this phenomenon must occur we discuss a particular hyperbolic PDE in one space dimension with boundary control and observation (a transmission line) that can be formulated both as a discrete time system and as a continuous time system, and show that in this example the continuous time Riccati equation can be recovered from the discrete time Riccati equation. A particular feature of this example is that the Riccati operator does not map the domain of the generator into the domain of the adjoint generator, as it does in the standard case.     

Phosphorus equilibrium between BaO-BaF2-MnO fluxes and ferro-manganese melts

The equilibrium distribution ratio of phosphorus between BaO-BaF₂-MnO slags and Mn(62–73%)-Fe-C_sat-P melts has been determined for different slag compositions, oxygen partial pressures and at 1573–1673 K. The results showed that with a certain content of BaO in the slags, the phosphorus distribution ratio increased with increasing oxygen partial pressure up to about 10^?17 atm. A high oxygen partial pressure resulted in a substantial oxidation of manganese from metal to slag. The phosphate capacity of BaO-BaF₂-MnO slags increased with the BaO content and decreased with the MnO content in the investigated slag composition range. A high temperature resulted in a low phosphorus distribution ratio. For a BaO(50%)-BaF₂(47%)-MnO(3%) slag, the effect of temperature on the phosphate capacity in the range of 1573–1673 K could be expressed as: (1) The heat of reaction: (2) was estimated to be ?1107 kJ/mole.     

Open innovation and public administration: transformational typologies and business model impacts

Extant research demonstrates that e-Government initiatives often fall short of achieving innovative forms of government and governance due to a techno-centric focus that limits such initiatives to minor improvements in service delivery. While it is evident that innovation is central to modernising and transforming governmental organisations, and that the co-creation of services by public authorities and community groups is an essential component of realising the benefits of investment in information and communication technology, there is little research focusing on the nature of innovation in transforming governmental organisations and services. Addressing this gap in the literature, this paper explores how open innovation strategies can transform public administration by examining how a network of municipalities in Sweden transforms value creation and service delivery by collaborating with each other and with external parties to accelerate the creation and exploitation of innovation. Using a case study with embedded units of analysis, four emerging typologies of governmental transformation based on open innovation are identified. The paper illustrates how these open innovation typologies (i) transform the organisation of the municipalities and (ii) help them deliver high quality co-created services to citizens. By examining the strategic and operational aspects that facilitate such activities, the analysis reveals the impact of open innovation on the business models of public authorities. The paper concludes that open innovation practices represent a more radical manifestation of transformational government than previously envisaged; signalling not only fundamental change in the nature of value creation and service delivery by public authorities, but potentially in the nature of their organisation.     

Explicit improved vertex control for uncertain,time‐varying linear discrete‐time systems with state and control constraints

A technique is presented to compute an explicit state feedback solution to the regulation problem for uncertain and/or time‐varying linear discrete‐time systems with state and control constraints. A piecewise affine control law is provided that not only guarantees recursive feasibility and robust asymptotic stability but is also optimal for a region of the state space containing the origin. Copyright © 2015 John Wiley & Sons, Ltd.     

Chemical defense in birch. Platyphylloside: A phenol fromBetula pendula inhibiting digestibility

Extracts of Scandinavian birch (Betula pendula Roth) buds and internodes of varying twig diameters have been investigated for their inhibitory effect on ruminant digestibility in vitro. The predominant inhibitory effect was observed in extracts containing the phenol platyphylloside, 5-hydroxy-1,7-bis-(4-hydroxy-phenyl)-3-heptan-one-3-O--d-glucopyranoside. Isolation of the pure compound and incubation with rumen inocula showed that digestibility was negatively related to the concentration. Significant effect was measured below the concentration naturally occurring in birch (0.8% of dry matter). Another isolated compound, the closely related rhododendrin, 4-(4-hydroxyphenyl)-2-butanol-2-O--d-glucopyranoside, did not depress digestibility within the concentrations found in birch. An important phenol of buds, apigenin-4,7-dimethylether, did not have any measurable effect on digestibility, while a nonphenolic fraction of bud extract had a slight inhibitory effect on digestibility. Implications for browsers feeding on birch are briefly discussed.     

Effects of separate carrier generation on the emission properties of InAs/GaAs quantum dots

Individual quantum dots have been studied by means of microphotoluminescence with dual-laser excitation. The additional infrared laser influences the dot charge configuration and increases the dot luminescence intensity. This is explained in terms of separate generation of excess electrons and holes into the dot from the two lasers. With increasing dot density and/or sample temperature, the increase of the luminescence intensity vanishes progressively, while the possibility to control the dot charge remains.