Effective Utilisation of Halophyte Biomass from Saline Soils for Biorefinering Processes

The salinity of European soil is increasing every year, causing severe economic damage (estimated 1–3 million hectares in the enlarged EU). This study uses the biomass of halophytes—tall fescue (grass) and hemp of the Białobrzeskie variety from saline soils—for bioenergy, second generation biofuels and designing new materials—fillers for polymer composites. In the bioethanol obtaining process, in the first stage, the grass and hemp biomass were pretreated with 1.5% NaOH. Before and after the treatment, the chemical composition was determined and the FTIR spectra and SEM pictures were taken. Then, the process of simultaneous saccharification and fermentation (SSF) was carried out. The concentration of ethanol for both the grass and hemp biomass was approx. 7 g·L⁻¹ (14 g·100 g⁻¹ of raw material). In addition, trials of obtaining green composites with halophyte biomass using polymers (PP) and biopolymers (PLA) as a matrix were performed. The mechanical properties of the composites (tensile and flexural tests) were determined. It was found that the addition of a compatibilizer improved the adhesion at the interface of PP composites with a hemp filler. In conclusion, the grass and hemp biomass were found to be an interesting and promising source to be used for bioethanol and biocomposites production. The use of annually renewable plant biomass from saline soils for biorefinering processes opens up opportunities for the development of a new value chains and new approaches to sustainable agriculture.     

N → C2 → C3 migration of the dichlorophosphino group in the synthesis of phosphorylated NH‐pyrroles

A successive N → C₂ → C₃ migration of the dichlorophosphino group has been found to occur in phosphorylation of unsubstituted pyrrole with phosphorus trichloride. As a result of this migration, a number of hitherto unknown C‐phosphorylated N‐unsubstituted pyrroles have been obtained. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:671–676, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20495     

Phosphorylation of N‐Silylpyrroles with Phosphorus Tribromide

Phosphorylation of N‐trimethylsilyl‐ and N‐dimethyl‐tert‐butylsilylpyrroles with phosphorus tribromide in pyridine proceeds selectively at position 3 of the pyrrole ring. Removal of the trialkylsilyl protecting group has furnished the first representatives of N‐unsubstituted 3‐phosphorylated pyrroles. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:93–96, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20416     

Induced magnetic anisotropy in Co-doped Finemet-type nanocrystalline materials

Transverse magnetic anisotropy has been induced in the Fe_14.7Co_58.8Cu₁Nb₃Si_13.5B₉ and Fe_13.8Co₆₅Cu_0.6Nb_2.6Si₉B₉ amorphous ribbons by annealing under an external magnetic field. This anisotropy plays a predominant role, compared to magneto-crystalline and magneto-elastic anisotropies, in forming the magnetic properties and shaping the hysteresis loop. The effect of temperature and time of annealing on the induced magnetic anisotropy and magnetic properties (magnetic permeability, coercivity and power losses) in both alloys was investigated. Under this work, measurements of frequency dependence of the real and imaginary parts of magnetic permeability were made within a frequency range up to 110 MHz. It was found that as a result of magnetic field annealing the Snoek limit increases in both alloys compared to the Co-free Finemet.     

First Copper(I) and Silver(I) Complexes Containing Phosphanylphosphido Ligands

Three new complexes with phosphanylphosphido ligands, [Cu₄{μ₂‐P(SiMe₃)‐PtBu}₄] ( 1 ), [Ag₄{μ₂‐P(SiMe₃)‐PtBu₂}₄] ( 2 ) and [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ ( 3 ) were synthesized and structurally characterized by X‐ray diffraction, NMR spectroscopy, and elemental analysis. Complexes 1 and 2 were obtained in the reactions of lithium derivative of diphosphane tBu₂P‐P(SiMe₃)Li · 2.7THF with CuCl and [iBu₃PAgCl]₄, respectively. The X‐ray diffraction analysis revealed that the complexes 1 and 2 present macrocyclic, tetrameric form with Cu₄P₄ and Ag₄P₄ core. Complex 3 was prepared in the reaction of CuCl with a different derivative of lithiated diphosphane iPr₂P‐P(SiMe₃)Li · 2(Diglyme). Surprisingly, the X‐ray analysis of 3 revealed that in this reaction instead of the tetramer the monomeric form, ionic complex [Cu{η¹‐P(SiMe₃)‐PiPr₂}₂]^–[Li(Diglyme)₂]⁺ was formed.     

Electron Transfer and Electron Excitation Processes in 2,5-Diaminoterephthalate Derivatives with Broad Scope for Functionalization

Derivatives of 2,5-diaminoterephthalate (DAT) are efficient fluorescence dyes that are also redox-active, thus allowing for the electrochemical manipulation of spectral properties. The electrochemical behaviour of seven DAT derivatives was studied by cyclic voltammetry in dichloromethane. In the absence of a proton donor, DATs should be oxidized in two one-electron steps. The first step is usually quasi-reversible while the second step is either quasi-reversible or irreversible. Some electrochemical properties such as the formal potentials and the ratio between the anodic and the cathodic current were determined from the cyclic voltammograms. Correlation between the formal potential of first oxidation and the absorption or the fluorescence emission wavelengths are established for this specific type of dyes. These correlations were confirmed with density functional theory calculations.     

Curing and properties of chloroprene and butadiene rubber (CR/BR) blends cross-linked with copper(I) oxide or copper(II) oxide

This paper discusses the curing and properties of chloroprene and butadiene rubber (CR/BR) blends cross-linked with copper(I) oxide (Cu₂O) or copper(II) oxide (CuO). The results revealed that the cross-linking degree of CR/BR blends decreased with the increasing amount of butadiene rubber (BR) in the blends. The mechanical properties of cured CR/BR blends depended on the proportion of elastomers in blends, as well as on the type and amount of the cross-linking agent (Cu₂O, CuO). The cross-linking of CR/BR/Cu₂O or CR/BR/CuO blends followed according to cationic mechanism, using Lewis acid, copper(I) chloride (CuCl) or copper(II) chloride (CuCl₂) generated in situ. Additionally, the prepared compositions, both unfilled and filled, were characterized by very high resistance to flame.     

On Trajectories of Analytic Gradient Vector Fields

Let f:Rⁿ,0→R,0 be an analytic function defined in a neighbourhood of the origin, having a critical point at 0. We show that the set of non-trivial trajectories of the equation xdot;=∇f(x) attracted by the origin has the same ?ech-Alexander cohomology groups as the real Milnor fibre of f.     

Synthesis and characterization of thiophene/3-alkylthiophene random cooligomers

Several random cooligomers based on thiophene and β-substituted alkyl derivatives, i.e. 3-methyl- and 3-octylthiophene, have been chemically synthesized by an oxidative coupling reaction in the presence of iron(III) chloride. The powdered samples were characterized by TGA, FTIR, UV and cyclic voltammetry measurements. The influence of the alkyl substituent on the homo/cooligomer stability, conjugation length, degree of polymerization and presence of defects is discussed. Electronic Publication     

Power controlled soliton stability and steering in lattices with saturable nonlinearity

Dynamical properties of discrete solitons in nonlinear Schr?dinger lattices with saturable nonlinearity are studied in the framework of the one-dimensional discrete Vinetskii-Kukhtarev model. Two stationary strongly localized modes, centered on site (A) and between two neighboring sites (B), are obtained. The associated Peierls-Nabarro potential is bounded and has multiple zeros indicating strong implications on the stability and dynamics of the localized modes. Besides a stable propagation of mode A, a stable propagation of mode B is also possible. The enhanced ability of the large power solitons to move across the lattice is pointed out and numerically verified.