Enhanced Ammonia Content in Compost Leachate Processed by Black Soldier Fly Larvae

Black soldier fly (BSF) larvae (Hermetia illucens), feeding on leachate from decaying vegetable and food scrap waste, increase ammonia (NH₄⁺) concentration five- to sixfold relative to leachate unprocessed by larvae. NH₄⁺ in larva-processed leachate reached levels as high as ∼100 mM. Most of this NH₄⁺ appears to have come from organic nitrogen within the frass produced by the larvae as they fed on leachate. In nitrate-enriched solutions, BSF larvae also facilitate dissimilatory nitrate reduction to ammonia. The markedly higher concentration of NH₄⁺ recovered in leachates processed with BSF larvae and concomitant diversion of nutrients into insect biomass (itself a valuable feedstock) indicate that the use of BSF larvae in processing leachate of decaying organic waste could be advantageous in offsetting capital and environmental costs incurred in composting.     

Heat-treatment influence on Ni–Fe–Cu–Mo nanocrystalline alloy obtained by mechanical alloying

The 77Ni14Fe5Cu4Mo (wt%) powders have been obtained by dry mechanical alloying of elemental powders in a planetary mill under argon atmosphere for milling durations ranging from 2 to 28?h. The alloy formation is obtained after 12?C16?h of milling, as shown by the X-ray diffraction and magnetic studies. The crystallite mean size is 13?±?2?nm after 28?h of milling. An optimal heat-treatment temperature was chosen after the analysis of the DSC signals. and the samples were heated at 350?°C for different durations ranging from 0.5 to 4?h. The heat treatment was continued to enhance the alloy formation and to eliminate the internal stresses induced during the milling process. The evolution of the phases amount during the heat treatment was calculated from the X-ray patterns using the Rietveld procedure.     

Structure simulation into a lamellar supramolecular network and calculation of the metal ions/ligands ratio

Background

Biosensors have attracted increasing attention as reliable analytical instruments in in situ monitoring of public health and environmental pollution. For enzyme-based biosensors, the stabilization of enzymatic activity on the biological recognition element is of great importance. It is generally acknowledged that an effective immobilization technique is a key step to achieve the construction quality of biosensors.

Results

A novel disposable biosensor was constructed by immobilizing laccase (Lac) with silica spheres on the surface of multi-walled carbon nanotubes (MWCNTs)-doped screen-printed electrode (SPE). Then, it was characterized in morphology and electrochemical properties by scanning electron microscopy (SEM) and cyclic voltammetry (CV). The characterization results indicated that a high loading of Lac and a good electrocatalytic activity could be obtained, attributing to the porous structure, large specific area and good biocompatibility of silica spheres and MWCNTs. Furthermore, the electrochemical sensing properties of the constructed biosensor were investigated by choosing dopamine (DA) as the typical model of phenolic compounds. It was shown that the biosensor displays a good linearity in the range from 1.3 to 85.5 ??M with a detection limit of 0.42 ??M (S/N = 3), and the Michaelis-Menten constant (K_m ^app) was calculated to be 3.78 ??M.

Conclusion

The immobilization of Lac was successfully achieved with silica spheres to construct a disposable biosensor on the MWCNTs-doped SPE (MWCNTs/SPE). This biosensor could determine DA based on a non-oxidative mechanism in a rapid, selective and sensitive way. Besides, the developed biosensor could retain high enzymatic activity and possess good stability without cross-linking reagents. The proposed immobilization approach and the constructed biosensor offer a great potential for the fabrication of the enzyme-based biosensors and the analysis of phenolic compounds.     

Crossed beam study of the atom-radical reaction of ground state carbon atoms (C(3P)) with the vinyl radical (C2H3(X2A'))

The atom-radical reaction of ground state carbon atoms (C((3)P)) with the vinyl radical (C(2)H(3)(X(2)A')) was conducted under single collision conditions at a collision energy of 32.3 ± 2.9 kJ mol(-1). The reaction dynamics were found to involve a complex forming reaction mechanism, which is initiated by the barrier-less addition of atomic carbon to the carbon-carbon-double bond of the vinyl radical forming a cyclic C(3)H(3) radical intermediate. The latter has a lifetime of at least 1.5 times its rotational period and decomposes via a tight exit transition state located about 45 kJ mol(-1) above the separated products through atomic hydrogen loss to the cyclopropenylidene isomer (c-C(3)H(2)) as detected toward cold molecular clouds and in star forming regions.     

On the stability of some classical operators from approximation theory

We obtain some results on Hyers–Ulam stability for some classical operators from approximation theory. For Bernstein operators we determine the Hyers–Ulam constant using a result concerning coefficient bounds of Lorentz representation for a polynomial.     

A Dynamic Programming Approach for Approximate Optimal Control for Cancer Therapy

In the last 15 years, tumor anti-angiogenesis became an active area of research in medicine and also in mathematical biology, and several models of dynamics and optimal controls of angiogenesis have been described. We use the Hamilton–Jacobi approach to study the numerical analysis of approximate optimal solutions to some of those models earlier analysed from the point of necessary optimality conditions in the series of papers by Ledzewicz and Schaettler.     

Precise Arrhenius Law for p-forms: The Witten Laplacian and Morse–Barannikov Complex

Accurate asymptotic expressions are given for the exponentially small eigenvalues of Witten Laplacians acting on p-forms. The key ingredient, which replaces explicit formulas for global quasimodes in the case p = 0, is Barannikov’s presentation of Morse theory in Barannikov (Adv Soviet Math 21:93–115, 1994).     

Strong rigidity of II1 factors arising from malleable actions of w-rigid groups, I

We consider crossed product II₁ factors , with G discrete ICC groups that contain infinite normal subgroups with the relative property (T) and σ trace preserving actions of G on finite von Neumann algebras N that are “malleable” and mixing. Examples are the actions of G by Bernoulli shifts (classical and non-classical) and by Bogoliubov shifts. We prove a rigidity result for isomorphisms of such factors, showing the uniqueness, up to unitary conjugacy, of the position of the group von Neumann algebra L(G) inside M. We use this result to calculate the fundamental group of M, , in terms of the weights of the shift σ, for and other special arithmetic groups. We deduce that for any subgroup S⊂ℝ₊^* there exist II₁ factors M (separable if S is countable or S=ℝ₊^*) with . This brings new light to a long standing open problem of Murray and von Neumann.