We study the pure braid groups Pn(RP) of the real projective plane RP2, and in particular the possible splitting of the Fadell-Neuwirth short exact sequence 1 −→ Pm(RP \ {x1, . . . , xn}) −֒→ Pn+m(RP 2) p∗ −→ Pn(RP) −→ 1, where n ≥ 2 and m ≥ 1, and p∗ is the homomorphismwhich corresponds geometrically to forgetting the last m strings. This problem is equivalent to that of the existence of a sect...

In a recent article Facchini and Finocchiaro considered natural pretorsion theory in the category of preordered sets inducing corresponding stable category. present work we propose an alternative construction $\mathsf{PreOrd} (\mathbb C)$ internal preorders any coherent $\mathbb C$, that enlightens categorical nature this notion. When C$ is pretopos prove quotient functor from to associated pre...

This study investigates the co-movements between Solactive Electric Vehicle and Future Mobility Index (EVFMI) multiple rare earth elements (REEs). We applied a TVP-VAR model bivariate wavelet coherence approach to capture both in time frequency domain considering short-, medium- long-term investment horizons. Using daily returns from 1 June 2012 4 2021, results of show that individual REEs EVFM...

We discuss intrinsic aspects of Krupka’s approach to finite–order variational sequences. We give intrinsic isomorphisms of the quotient subsheaves of the short finite– order variational sequence with sheaves of forms on jet spaces of suitable order, obtaining a new finite–order (short exact) variational sequence which is made by sheaves of polynomial differential operators. Moreover, we present...

The Rees algebra of an ideal is a classical object that has been studied throughout many decades. Our interest to Rees algebras comes from the fact that they provide the algebraic realizations for certain class of rational n-folds, namely those obtained from P by blowing up at a subscheme. In this paper, we study the Rees algebras of certain codimension two perfect ideals. To be more precise, w...

The determination of rare earth elements (REEs) in airborne particulate matter (APM) was conducted, and the distribution pattern of atmospheric REEs was evaluated in this study. The APM was collected in the center of Tokyo, Japan, where serious air pollution is always of concern. A cellulose acetate membrane filter was used to collect the APM because Ba and REEs contamination is lower than that...

There are many sources trough which the soil get enriched and contaminated with REEs. The determination of REEs in environmental samples has been limited because of the lack of sensitive analytical techniques. Soil samples were collected from four sites including open cast coal mine, natural coal burning, coal washery and control in the coal field located in Dhanbad, India. Total concentrations...