Beyond 90-km Reach of a 16 × 2.5 Gb/s C/L-band Dense Wavelength-Division Multiplexing Metropolitan Network Based on Self-Seeded Reflective Semiconductor Optical Amplifiers

Abstract

This article reports the operation of a cost-effective, colorless, dense wavelength-division multiplexing metropolitan network based on self-seeded reflective semiconductor optical amplifiers. All reflective semiconductor optical amplifiers used in the experiments are packaged in commercial small form-factor pluggable modules. The proposal architecture is simple and symmetric thanks to utilization of two cyclic array waveguide gratings. Downstream link functions in the C-band wavelength range and the upstream link functions in the L-band wavelength range. By using erbium-doped fiber amplifiers to extend the reach, an error-free transmission over 90 km for 16 channels at 2.5 Gb/s was experimentally demonstrated for both directions, and an optical budget over 35 dB was obtained.     

Folding of Set-Theoretical Solutions of the Yang–Baxter Equation

We establish a correspondence between the invariant subsets of a non-degenerate symmetric set-theoretical solution of the quantum Yang–Baxter equation and the parabolic subgroups of its structure group, equipped with its canonical Garside structure. Moreover, we introduce the notion of a foldable solution, which extends the one of a decomposable solution.     

Reactions of organic peroxy radicals,RO2, with substituted and biogenic alkenes at room temperature: unsuspected sinks for some RO2 in the atmosphere?

Until now the reactions of organic peroxy radicals (RO₂) with alkenes in the gas phase have been essentially studied at high temperature (T ≥ 360 K) and in the context of combustion processes, while considered negligible in the Earth''s atmosphere. In this work, the reactions of methyl-, 1-pentyl- and acetylperoxy radicals (CH₃O₂, C₅H₁₁O₂, and CH₃C(O)O₂, respectively) with 2-methyl-2-butene, 2,3-dimethyl-2-butene and for the first time the atmospherically relevant isoprene, α-pinene, and limonene were studied at room temperature (298 ± 5 K). Monitoring directly the radicals with chemical ionization mass spectrometry led to rate coefficients larger than expected from previous combustion studies but following similar trends in terms of alkenes, with (in molecule⁻¹ cm³ s⁻¹) = 10⁻¹⁸ to 10⁻¹⁷ × 2/2 and = 10⁻¹⁴ to 10⁻¹³ × 5/5. While these reactions would be negligible for CH₃O₂ and aliphatic RO₂ at room temperature, this might not be the case for acyl-, and perhaps hydroxy-, allyl- and other substituted RO₂. Combining our results with the Structure–Activity Relationship (SAR) predicts k^II(298 K) ∼10⁻¹⁴ molecule⁻¹ cm³ s⁻¹ for hydroxy- and allyl-RO₂ from isoprene oxidation, potentially accounting for up to 14% of their sinks in biogenic-rich regions of the atmosphere and much more in laboratory studies.

The reactions of organic peroxy radicals with alkenes, overlooked until now, could be more significant than expected for some RO₂ in the atmosphere.     

Application of conjoint liquid chromatography with monolithic disks for the simultaneous determination of immunoglobulin G and other proteins present in a cell culture medium

The aim of this study was to develop a chromatographic method, as a substitute for enzyme-linked immunosorbent assays, for the rapid and simultaneous detection of IgG, insulin, and transferrin present in a cell culture medium. Conjoint liquid chromatography (conjoint LC) using monolithic disks was applied for this purpose. An anion-exchange disk was combined with a Protein G affinity disk in a preparative HPLC system. IgG bound to the Protein G disk, whereas transferrin and insulin were captured on the quaternary ammonium (QA) disk. Using this method, it was possible to simultaneously determine the concentrations of IgG, transferrin, and insulin in the cell culture medium. Thus, conjoint LC could be used for the rapid and simultaneous detection of different proteins present in a cell culture medium.     

Rewriting systems in alternating knot groups with the Dehn presentation

Every tame, prime and alternating knot is equivalent to a tame, prime and alternating knot in regular position, with a common projection. In this work, we show that the Dehn presentation of the knot group of a tame, prime, alternating knot, with a regular and common projection has a finite and complete rewriting system. Although there are rules in the rewriting system with left-hand side a generator and which increase the length of the words we show that the system is terminating.      

Synthesis of amorpha-4,11-diene from dihydroartemisinic acid

Amorphadiene is a natural product involved in the biosynthesis of the antimalarial drug artemisinin. A convenient four-step synthesis of amorphadiene, starting from commercially available dihydroartemisinic acid, is reported. The targeted molecule is isolated with an overall yield of 85% on a multi-gram scale in four steps with only one chromatography.     

Application of direct solid analysis of plant samples by electrothermal vaporization-inductively coupled plasma atomic emission spectrometry: Determination of Cd and Si for environmental purposes

Elemental determinations are usually performed on plant samples for agronomic or environmental studies. Direct solid sampling is possible when electrothermal vaporization (ETV) is used as a method of sample introduction in inductively coupled plasma atomic emission spectrometry (ICP-AES). ETV-ICP-AES was applied for elemental determinations in plant samples. The first application aimed at Cd determinations in very small size plant material samples. Several reference plant materials were used to validate the accuracy of the method. Quality control included the systematic analysis of a reference sample in each batch of unknown samples. The performance of the method in time was illustrated by a control chart. The second application aimed at the content of Si in plant materials. Quantification of Si in plant samples was carried out using samples issued from an inter-laboratory test. Detection limit of 30 μg g^− 1 was achieved for Si. In all cases, quantification was accomplished easily by means of aqueous standard solutions deposited on cellulose support.     

Decarboxylative Claisen rearrangement reactions of allylic tosylmalonate esters

[reaction: see text] Two different combinations of silylating agent and base are used for one-pot [3,3]-sigmatropic rearrangement-decarboxylation reactions of tosylmalonic mono(allylic) esters under mild conditions, providing the products of formal regiospecific allylation of methyl tosylacetate at the more substituted allylic terminus.