The Molecular and Crystal Structures of 2-Iodokojic Acid: Experimental and Theoretical Determination

Abstract  

The crystal structure of 2-iodokojic acid, (2-jodo-3-hydroxy-6-hydroxymethyl)-4-H-pyran-4-one) (C₆H₅IO₄, Mr = 268.00) has been determined by single crystal X-ray diffraction analysis. The compound crystallizes in the orthorhombic crystal system with space group Pc2₁b and unit cell parameters: a = 4.0830(2), b = 15.3510(5), c = 23.517(1) ? and Z = 8. The final reliability index is 0.0288 for 2,584 observed reflections. The two molecules of iodokojic acid, slightly differing in their molecular structure, are localized in independent part of unit cell. The crystal packing is stabilized by O–H···O hydrogen bonds and I···O intermolecular interactions. The molecular structure of iodokojic acid determined experimentally little differs from that obtained by the applied theoretical (Hartree–Fock and four versions of DFT) methods, the differences should not be taken as a measure of the reliability of the theoretical methods.     

Perfect residuated lattice ordered monoids

Bounded Rℓ-monoids form a large subclass of the class of residuated lattices which contains certain of algebras of fuzzy and intuitionistic logics, such as GMV-algebras (= pseudo-MV-algebras), pseudo-BL-algebras and Heyting algebras. Moreover, GMV-algebras and pseudo-BL-algebras can be recognized as special kinds of pseudo-MV-effect algebras and pseudo-weak MV-effect algebras, i.e., as algebras of some quantum logics. In the paper, bipartite, local and perfect Rℓ-monoids are investigated and it is shown that every good perfect Rℓ-monoid has a state (= an analogue of probability measure).     

Commuting Linear Operators and Decompositions; Applications to Einstein Manifolds

For linear operators which factor P=P ₀ P ₁ ??? P _? , with suitable assumptions concerning commutativity of the factors, we introduce several notions of a decomposition. When any of these hold then questions of null space and range are subordinated to the same questions for the factors, or certain compositions thereof. When the operators P _i are polynomial in other commuting operators \(\mathcal{D}_{1},\ldots,\mathcal{D}_{k}\) then we show that, in a suitable sense, generically factorisations algebraically yield decompositions. In the case of operators on a vector space over an algebraically closed field this boils down to elementary algebraic geometry arising from the polynomial formula for P. The results and formulae are independent of the \(\mathcal{D}_{j}\) and so the theory provides a route to studying the solution space and the inhomogenous problem Pu=f without any attempt to “diagonalise” the \(\mathcal{D}_{j}\). Applications include the construction of fundamental solutions (or “Greens functions”) for PDE; analysis of the symmetry algebra for PDE; direct decompositions of Lie group representations into Casimir generalised eigenspaces and related decompositions of vector bundle section spaces on suitable geometries. Operators P polynomial in a single other operator \(\mathcal{D}\) form the simplest case of the general development and here we give universal formulae for the projectors administering the decomposition. As a concrete geometric application, on Einstein manifolds we describe the direct decomposition of the solution space and the general inhomogeneous problem for the conformal Laplacian operators of Graham-Jenne-Mason-Sparling.     

Asymptotics of Stationary Navier Stokes Equations in Higher Dimensions

We show that the asymptotics of solutions to stationary Navier Stokes equations in 4, 5 or 6 dimensions in the whole space with a smooth compactly supported forcing are given by the linear Stokes equation. We do not need to assume any smallness condition. The result is in contrast to three dimensions, where the asymptotics for steady states are different from the linear Stokes equation, even for small data, while the large data case presents an open problem. The case of dimension n = 2 is still harder.     

Preparation of <Superscript>95m</Superscript>Tc radiotracer

Several procedures for preparation of the ^95mTc radiotracer following irradiation of a thin Mo target with deuterons were tested. The procedures consisting of alkaline-oxidative fusion of the irradiated target in a mixture of Na₂O₂ + NaOH and subsequent liquid–liquid extraction with 2-butanone, and acid decomposition of the target in a mixture of H₂SO₄ + HNO₃ followed by extraction chromatography with PAN-Aliquat 336 composite material appeared suitable for the given purpose.     

Local bounded commutative residuated ℓ-monoids

Bounded commutative residuated lattice ordered monoids (Rℓ-monoids) are a common generalization of, e.g., BL-algebras and Heyting algebras. In the paper, the properties of local and perfect bounded commutative Rℓ-monoids are investigated.     

Kinematic Model for Determination of Human Arm Reachable Workspace

In physiotherapy, a standard method to determine the movability and functionality of the human arm is to measure the ranges of motion in joints in sagittal, horizontal and frontal plane. It is clear, however, that these angles can hardly interpret the characteristics of the arm. The main idea in the article is to combine these angles with an adequate kinematic model in order to compute and graphically represent the reachable workspace of the arm, which then serves as an advanced criterion for a more objective evaluation. In this article, we report an improved kinematic model of the human arm which is appropriate for computing and visualizing the human arm reachable workspace. Optical measurements were performed to define the structure and parameters of the model and to develop the mathematical relations between the joint angles. The kinematic model was implemented in a computer programme which is now being introduced in practice and can be used in rehabilitation, ergonomics and sports.     

Etching and recovery of gold from aluminum substrate in thiourea solution

This paper deals with two (main) problems of specific gold etching from parts of industrial equipment (e.g., supporting inserts into chambers for physical or chemical vapor deposition). First part of the paper is focused on selective etching of gold from aluminum substrates. Selectivity of the reaction, i.e. leaving substrates intact, is crucial. For this reason, the environmentally friendly and safe method of etching gold in a thiourea solution was tested. This method, while well described in literature, does not preserve various substrates (e.g., aluminum, stainless steel). The main goal of this part of the paper was to understand the mechanism of the reaction and to improve the reaction selectivity towards the aluminum alloy substrate. Thus, different acidifying agents were tested. Second part of the paper is focused on recovery (reduction) of gold from thiourea solutions. Chemical, electrochemical, and biological reduction were tested for gold recovery.