Non-invasive characterisation of SIX Japanese hand-guards (tsuba)

In this work we present a systematic study of Japanese sword hand-guards (tsuba) carried out by means of non-invasive techniques using neutrons. Several tsuba from different periods, belonging to the Japanese Section of the Stibbert Museum, were analysed using an innovative approach to characterise the bulk of the samples, coupling two neutron techniques, namely Time of Flight Neutron Diffraction (ToF-ND) and Nuclear Resonance Capture Analysis (NRCA). The measurements were carried out on the same instrument: the INES beam-line at the ISIS spallation pulsed neutron source (UK). NRCA analysis allows identifying the elements present in the sample gauge volume, while neutron diffraction is exploited to quantify the phase distribution and other micro-structural parameters of the metal specimen. The results show that all samples are made of high-quality metal, either steel or copper alloy, with noticeable changes in composition and working techniques, depending on the place and time of manufacturing.     

Concept and synthetic approach for a kilogram scale synthesis of octa-d-arginine amide nonahydrochloride salt

Oligomers of arginine, such as octa-d-arginine amide, are excellent transporters for active drugs through cell membranes and tissue. The synthesis of octa-d-arginine amide, as the nonahydrochloride salt, was approached via a solution phase synthetic route involving the preparation of an octa-d-ornithine intermediate, which was then converted into the desired octa-d-arginine compound through a guanidinylation step. The multi-step synthesis was carried out at pilot scale, resulting in the preparation of 700 g of the target molecule. No chromatographic purification was needed at any step of the process.     

A class of methods for solving large,convex quadratic programs subject to box constraints

In this paper we analyze conjugate gradient-type algorithms for solving convex quadratic programs subject only to box constraints (i.e., lower and upper bounds on the variables). Programs of this type, which we denote by BQP, play an important role in many optimization models and algorithms. We propose a new class of finite algorithms based on a nonfinite heuristic for solving a large, sparse BQP. The numerical results suggest that these algorithms are competitive with Dembo and Tulowitzski's (1983) CRGP algorithm in general, and perform better than CRGP for problems that have a low percentage of free variables at optimality, and for problems with only nonnegativity constraints.     

Reaction of 2-dimethylaminomethylene-1,3-diones with dinucleophiles. I. Synthesis of 1,5-disubstituted 4-acylpyrazoles

Reaction of open-chain and cyclic sym-1,3-diones with N,N-dimethylformamide dimethyl acetal gave, generally in high yield, a series of sym-2-dimethylaminomethylene-1,3-diones which reacted with phenylhydrazine and methylhydrazine to afford, generally in satisfactory yield, a number of 1,5-disubstituted 4-acylpyrazoles. The applications and limits of this new pyrazole synthesis are presented and discussed.     

Ionization and Partitioning Profiles of Zwitterions: The case of the anti-inflammatory drug azapropazone

Azapropazone ( 1 ) is a non-steroidal anti-inflammatory drug (NSAID) whose chemical structure is markedly different from that of other agents in this class and challenges our understanding of structure-activity and structure-permeation relationships. Using a variety of experimental and computational techniques, we studied 1 for its molecular structure in the gas phase and non-protic polar solvents, protonation/deprotonation equilibra, tautomerism, and pH-lipophilicity profiles (octan-1-ol/H₂O and dodecane/H₂O). Other NSAIDs and model compounds were also examined for comparison. Due to its very low acidic pK_a1, 1 exists in the physiological pH range as a zwitterion and as an anion. Some pharmacological implications of these findings are discussed.     

Exact penalty functions in nonlinear programming

In this paper some new theoretic results on piecewise differentiable exact penalty functions are presented. Sufficient conditions are given for the existence of exact penalty functions for inequality constrained problems more general than concave and several classes of such functions are presented.This research was partially supported by a grant from the Office of Naval Research; contract number N00014-67-A-0321-0003 (NR047-095).     

Transferability of optical bowing parameters between binary and ternary group-IV alloys

We present a detailed analysis of the compositional dependence of the average of the E₁ and E₁+Δ₁ transition energies in Ge_1−x−ySi_xSn_y alloys. We show that this dependence can be explained in terms of three bowing parameters—b^SiGe, b^GeSn, and b^SiSn—which scale with the product ΔχΔR of the Phillips electronegativity and size mismatches between Si, Ge, and Sn.     

S3O and S3O+ in the gas phase: Ring and open-chain structures

Ring and open-chain S3O sulfur oxides are detected by neutralization-reionization experiments.     

γ-Valerolactone (GVL) as a green and efficient dipolar aprotic reaction medium

The great challenge for modern research is to define the most efficient tools to make more sustainable the industrial production and manufacturing. Among the different aspects that require attention the replacement of toxic and/or non-renewable solvents it is certainly playing a crucial role. Dealing with widely used dipolar aprotic solvents, among the different alternatives proposed in the literature γ-valerolactone (GVL) plays a pivotal role covering different application area. In this contribution, the benefits derived from the use of GVL as a circular, safe, biomass-derived reaction medium are highlighted covering most recent publications (2021). The presentation has been divided into three major sections: (i) biomass valorization, (ii) materials synthesis, manufacturing and recycle and (iii) new synthetic methodologies.     

Development and application of electrochemical sensor of boron-doped diamond (BDD) modified by drop casting with tin hexacyanoferrate

Journal of Solid State Electrochemistry - This work presents the development and characterization of an electrochemical sensor of tin hexacyanoferrate (SnHCF), produced from the modification by...