The algebra and geometry ofSU(3) matrices

We give an elementary treatment of the defining representation and Lie algebra of the three-dimensional unitary unimodular groupSU(3). The geometrical properties of the Lie algebra, which is an eight dimensional real linear vector space, are developed in anSU(3) covariant manner. Thef andd symbols ofSU(3) lead to two ways of ‘multiplying’ two vectors to produce a third, and several useful geometric and algebraic identities are derived. The axis-angle parametrization ofSU(3) is developed as a generalization of that forSU(2), and the specifically new features are brought out. Application to the dynamics of three-level systems is outlined.     

Spin squeezing and quantum correlations

We discuss the notion of spin squeezing considering two mutually exclusive classes of spin-s states, namely, oriented and non-oriented states. Our analysis shows that the oriented states are not squeezed while non-oriented states exhibit squeezing. We also present a new scheme for construction of spin-s states using 2s spinors oriented along different axes. Taking the case of s=1, we show that the ‘non-oriented’ nature and hence squeezing arise from the intrinsic quantum correlations that exist among the spinors in the coupled state.     

A simple and convenient method for the synthesis of cyclobutenediones from alkynes using new Fe(CO)5/NaH/MeI reagent system

Iron carbonyl complexes prepared in situ using the Fe(CO)₅/NaH/MeI reagent combination and alkynes at 25 °C give the corresponding cyclobutenediones in 50-65% yields after CuCl₂ · 2H₂O oxidation.     

Improved catalytic properties of Co3O4-impregnated La2O3/MgO over Co3O4/MgO catalyst in the oxidative dehydrogenation of ethylbenzene

Research on Chemical Intermediates - A series of lanthanum oxide (La2O3—2–14 wt%)-encapsulated Co3O4/MgO catalysts and bare Co/MgO solid oxides were prepared by wetness...     

Reactive iron carbonyl reagents via reaction of metal alkoxides with Fe(CO)5 or Fe2(CO)9: synthesis of cyclobutenediones via double carbonylation of alkynes

Alkoxy bases such as t-BuOK react with Fe(CO)(5) to give reactive iron carbonyl intermediates that in turn react with alkynes at 70 °C in THF to give 1,2-cyclobutenediones in 70-93% yields after CuCl(2)·2H(2)O oxidation. A novel 1,2-diacyloxyferrole derivative was isolated in the reaction of diphenylacetylene with Fe(CO)(5)/t-BuOK in the presence of acetyl chloride in contrast to the formation of a 1,4-diacyloxyferrole complex formed in the reaction using Fe(CO)(5)/Me(3)NO. The Fe(2)(CO)(9)/t-BuOK reagent system also converts the alkynes to corresponding cyclobutenediones in 63-90% yields under similar reaction conditions.     

Assessment of environmental radioactive elements in groundwater in parts of Nalgonda district,Andhra Pradesh,South India using scintillation detection methods

The objective of this work was to determine the radioactive element concentrations in groundwater in parts of the Nalgonda district. Results indicate that ²²²Rn activity is present in significant levels in deep groundwater compared to shallow groundwater and tank water. An increasing ²²²Rn activity trend is noticed along the well depth while electrical conductivity, uranium, and alkalinity levels showed inverse trends. Environmental tritium data indicates modern recharge to groundwater. Inter-elemental correlations suggest that high dissolved uranium is associated with high alkalinity and high electrical conductivity groundwater. The study also infers recharge sources and mechanisms to shallow and deep groundwater.     

Ile‐Lys‐Val‐ala‐Val (IKVAV) peptide for neuronal tissue engineering

Despite the great advances in microsurgery, some neural injuries cannot be treated surgically. Stem cell therapy is a potential approach for treating neuroinjuries and neurodegenerative disease. Researchers have developed various bioactive scaffolds for tissue engineering, exhibiting enhanced cell viability, attachment, migration, neurite elongation, and neuronal differentiation, with the aim of developing functional tissue grafts that can be incorporated in vivo. Facilitating the appropriate interactions between the cells and extracellular matrix is crucial in scaffold design. Modification of scaffolds with biofunctional motifs such as growth factors, drugs, or peptides can improve this interaction. In this review, we focus on the laminin‐derived Ile‐Lys‐Val‐Ala‐Val peptide as a biofunctional epitope for neuronal tissue engineering. Inclusion of this bioactive peptide within a scaffold is known to enhance cell adhesion as well as neuronal differentiation in both 2‐dimensional and 3‐dimensional environments. The in vivo application of this peptide is also briefly described.     

Comparative analysis of entanglement measures based on monogamy inequality

We evaluate the monogamy inequality for symmetric, non-symmetric pure states of importance in terms of squared concurrence, squared entanglement of formation, squared negativity of partial transpose and compare the corresponding tangles. We show that though concurrence and concurrence tangle are zero for two special classes of mixed entangled states, both negativity tangle and entanglement of formation(EOF) tangle turn out to be non-zero. A comparison of different tangles is carried out in each case and it is shown that while the concurrence tangle captures the genuine multiqubit entanglement in N-qubit pure states with N distinct spinors(containing GHZ and superposition of W-, obverse W states)either negativity tangle or EOF tangle is to be used as a better measure of entanglement in the W-class of states with two distinct spinors and in the special classes of mixed multiqubit states.     

Polarization parameters in systems with spin-spin interactions

The spin-spin interaction of two arbitrary spin systems is considered in some detail. The temporal evolution of the polarization parameters and the correlation parameters has been worked out. Applications of the formalism and the interpretation of the results to processes such as heavy-ion interactions, muon and nuclear repolarization and depolarization in muonic atoms and interactions of multilevel systems are outlined.