Jordan Ideals Revisited

An alternative approach to the study of Jordan ideals in associative algebras is considered. The same method can be used when analogous questions in graded algebras are treated.     

Central polynomials for matrices over finite fields

Let c(x ₁,?…?,?x _d ) be a multihomogeneous central polynomial for the n?×?n matrix algebra M _n (K) over an infinite field K of positive characteristic p. We show that there exists a multihomogeneous polynomial c ₀(x ₁,?…?,?x _d ) of the same degree and with coefficients in the prime field 𝔽 _p which is central for the algebra M _n (F) for any (possibly finite) field F of characteristic p. The proof is elementary and uses standard combinatorial techniques only.     

Commuting maps on lie ideals

Let R be a ring and let A be a subset of R. A map f : A→ R is commuting on A if [f(x),x]= 0 for all xεA where [x,y] = xy — yx. Suppose that R is a prime ring of characteristic ≠2 with extended centroid C. If L is a noncommutative Lie ideal of R and f:L→R an additive commuting map, then there is λε C and an additive map ∈: L→ C such that f(v) = λ(v)=λv+∈((v) for all vεL.     

Fault propagation behavior study of CSTR in HAZOP

This paper discusses the role of process modeling in safety analysis. Process modeling is applied in the fault propagation behavior study of CSTR chemical production. For that purpose, HAZOP methodology and continuation analysis were used. The proposed hazard identification methodology involves analysis of steady-state multiplicity and safe operating conditions as well as those which can shift process units from one steady state to another. All presented case studies are also supported by system dynamic simulations, essential to detect oscillatory thermal instability. In this paper, N-oxide alkylpyridines production process was chosen to identify potential hazard and operational problems. Presented dynamic simulations represent an analysis of the system response to step changes in the key operating parameters. The effect of deviations of three key parameters on the reactor safe operation was investigated. The proposed numerical algorithms represent a mathematical engine of the simulation module within an automated model-based HAZOP analysis tool.     

Plasma-based preparation of polyaniline/graphene and polypyrrole/graphene composites for dye-sensitized solar cells as counter electrodes

This study presents the preparation of graphene (GR) nanocomposites with polyaniline (PANI) and polypyrrole (PPy) through the fast, versatile and environmentally friendly process of radio frequency (RF)-plasma polymerization. Morphological characterization of the nanocomposites is performed using scanning electron microscopy (SEM) and shows that the PANI and PPy conducting polymers coated the GR surface. The surface properties of the GR nanocomposites are determined using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The prepared GR nanocomposites are then used as counter electrodes in dye-sensitized solar cells (DSSCs). The conversion cell efficiencies for iodine-doped DSSC samples are found to be 0.086%, 5.41%, and 5.60% for I₂-PANI, I₂-PANI-GR and I₂-PPy-GR, respectively, while the corresponding undoped samples reaches power conversion efficiencies of 3.82%, 1.30%, and 0.077% for PPy-GR, PANI-GR and PANI, respectively. The incident photon-to-current efficiency (IPCE) of iodine-doped composite-based DSSCs is significantly enhanced.