Doping of KDP single crystals with cerium: Growth and optical properties

The features of doping of KDP crystals with cerium ions and organocerium complexes with alizarin complexon and arsenazo III have been investigated. It is established that “direct” doping by introducing cerium salts into the initial solution cannot be implemented. The effect of organometallic complexes of cerium on the crystal growth has been studied. Organocerium complexes predominantly enter the prismatic or pyramidal growth sectors. It is shown that the complex arsenazo III + Ce blocks the growth of the prismatic sector. Cerium-doped KDP crystals exhibit a photoluminescence band peaking at the wavelength λ_max= 350 nm.     

New Interfaces for Coupling TLC with TOF SIMS

JPC – Journal of Planar Chromatography – Modern TLC - Two interfaces have been tested for coupling thin-layer chromatography (TLC) with time-of-flight secondary-ion mass spectrometry...     

Internal segregation of nanoparticles irradiated by laser radiation

The effect of the removal of zinc from brass nanoparticles has been experimentally discovered upon irradiating their suspension in ethanol by laser radiation. The analysis of the absorption spectra of nanoparticles shows that brass nanoparticles are transformed to copper nanoparticles during irradiation. The results are interpreted in terms of the high-pressure-induced modification of the phase diagram of nanoparticles. This pressure is caused by, first, the small radius of nanoparticles and, second, the pressure of the surrounding-liquid vapors upon the laser heating of nanoparticles.     

Modelling locational price spreads in competitive electricity markets; applications for transmission rights valuation and replication

The restructuring of the electric utilities industry has forcedindustry participants to rethink their approach to a numberof decision processes. To manage risk and plan investment ingeneration assets, as well as to examine the efficient expansionof the current transmission grid, one needs to have a clearunderstanding of the interaction between the grid propertiesand the behaviour of the regional power markets. In this paperwe discuss a fundamental modelling approach which extracts thestochastic properties of electricity prices by modelling theimpact of physical and economic drivers affecting the production,delivery, and consumption of electricity. If the fundamentalinputs are directly observable, we can use historical data tocalibrate the model parameters. In the case of electricity,this simple and abundant set of training data can make a crucialdifference. We present the bid-based stochastic model (BSM) and look intoits application to valuing of financial derivatives, especiallyoptions based on the locational spread in electricity pricebetween two markets. The advantage of the bid-based model isthat one is able to link the capacity of the transmission line,in megawatts, directly to the correlation between electricityprices at the end nodes. This leads us to a valuation methodfor a locational spread option, the financial equivalent ofa physical transmission right. The model represents an improvementover standard spread option formulation in that it accountsfor the effect of the nonlinear flows in the transmission networkon the correlation and distribution of locational prices. Wealso address the question of whether financial transmissionrights can be replicated with a dynamic portfolio of forwardcontracts at the end nodes. This poses the possibility of model-based arbitrage betweenexisting forward markets and the emerging transmission rightsmarkets. Furthermore, it allows users to simulate the effectof transmission outages or expansion. For example, a for-profittransmission provider who is contemplating addition of a newtransmission line between two markets needs to know whetherhe will be able to recover the fixed cost of investing in theline by selling transmission rights to market participants.By calibrating the bid-based model according to current pricelevels and adding the capacity of the new transmission line,the transmission owner can simulate future cash flows and estimatethe profitability of the investment.     

Standardization and certification in the area of environmentally degradable plastics

Environmentally degradable polymers and plastics (EDPs) are a group of polymeric materials experiencing a rapid growth in number as well as in their applications and quantities used. The assessment of their key characteristic - degradability, including eventually biodegradability as the ultimate stage, is scientifically and technically a challenging issue and has led to differing interpretations in the past. In order to standardize techniques and criteria a number of standards were established by different standardization bodies which are also used as a basis for certification schemes. An up-to-date inventory of the rapidly growing standardization body is presented with basic interpretation to help guide the non-expert. A basic introduction to EDPs and polymer degradation is added for clarity.     

Damping width of double resonances

Damping width of the double giant dipole resonance of ¹³⁶Xe excited in relativistic heavy ion collisions is calculated by diagonalizing a microscopic Hamiltonian in a basis containing one-, two- and three-phonon states. The coupling between these states is determined making use of the fermion structure of the phonons. The resulting width of the double giant dipole resonance is close to \(\left( {3_1^ + } \right)\) times the width of the single giant dipole resonance.     

The complexing ability and structure of Si-substituted silatranes

The proton NMR spectra of Si-substituted silatranes, a new class of biologically active compounds, measured in the presence of Co²⁺, Ni²⁺ and Eu³⁺ ions are examined. These silatranes coordinate with Co²⁺ and Ni²⁺ through a nitrogen atom and with Eu³⁺ through an oxygen atom mainly without transition to the exo-form. The electronic structure of nitrogen in silatranes is the same as that of pyrrol nitrogen. This suggests that in silatranes a nitrogen lone pair and oxygen lone pairs form common electron system analogous, for example, to the π-system of unsaturated cycles.