Differential and Single-Ended Microstrip Lines Loaded with Slotted Magnetic-LC Resonators

This paper is focused on magnetic-LC (MLC) resonators, namely, slotted resonators that can be considered the complementary counterparts of the so-called electric-LC (ELC) resonators. Both resonators exhibit two symmetry planes (i.e., they are bisymmetric), one of them being an electric wall and the other a magnetic wall at the fundamental resonance. Therefore, compared to other electrically small resonators such as folded stepped impedance resonators (SIRs), split ring resonators (SRRs), and their complementary counterparts, MLC and ELC resonators exhibit a very rich phenomenology. In this paper, single-ended microstrip lines and differential microstrip lines loaded with MLC resonators are studied, and potential applications are highlighted

Angular displacement and velocity sensors based on coplanar waveguides (CPWs) loaded with S-shaped split ring resonators (S-SRR)

In this paper, angular displacement and angular velocity sensors based on coplanar waveguide (CPW) transmission lines and S-shaped split ring resonators (S-SRRs) are presented. The sensor consists of two parts, namely a CPW and an S-SRR, both lying on parallel planes. By this means, line-to-resonator magnetic coupling arises, the coupling level being dependent on the line-to-resonator relative angular orientation. The line-to-resonator coupling level is the key parameter responsible for modulating the amplitude of the frequency response seen between the CPW ports in the vicinity of the S-SRR fundamental resonance frequency. Specifically, an amplitude notch that can be visualized in the transmission coefficient is changed by the coupling strength, and it is characterized as the sensing variable. Thus, the relative angular orientation between the two parts is measured, when the S-SRR is attached to a rotating object. It follows that the rotation angle and speed can be inferred either by measuring the frequency response of the S-SRR-loaded line, or the response amplitude at a fixed frequency in the vicinity of resonance. It is in addition shown that the angular velocity can be accurately determined from the time-domain response of a carrier time-harmonic signal tuned at the S-SRR resonance frequency. The main advantage of the proposed device is its small size directly related to the small electrical size of the S-SRR, which allows for the design of compact angular displacement and velocity sensors at low frequencies. Despite the small size of the fabricated proof-of-concept prototype (electrically small structures do not usually reject signals efficiently), it exhibits good linearity (on a logarithmic scale), sensitivity and dynamic range.Jordi Naqui, Jan Coromina, Ali Karami-Horestani, Christophe Fumeaux and Ferran Martí

Eco-Friendly, Green Approach for Synthesis of Bio-Active Novel 3-Aminoindazole Derivatives

In present chapter we have reported green and highly efficient method for synthesize novel series of substituted -1H-indazol-3-amine derivative (3a-h) by cyclocondensation reaction of substituted benzonitrile (1a-h) and substituted Hydrazine (2a-h) using ceric (IV) ammonium nitrate (CAN) as a catalyst, EtOH-H2O as a ecofriendly media and reaction was carried out under ultrasound irradiation green method. The structures of newly synthesized indazole derivative (3a-h) were corroborated through spectral investigation such as elemental analysis and spectral studies like IR, C13 NMR, Mass spectra and 1H NMR. The compounds were assessed for their in-vitro antimicrobial activity with pathogenic microbe comprising Gram positive bacterial strains, S. aureus and Gram negative strains E.coli, P.vulgaris, and S. typhi at different concentration. The consequence of bioassay is compared with standard drug Chloramphenicol

Specificities of a chemically modified laccase from trametes hirsuta on soluble and cellulose-bound substrates

Laccases could prevent fabrics and garments from re-deposition of dyes during washing and finishing processes by degrading the solubilized dye. However, laccase action must be restricted to solubilized dye molecules thereby avoiding decolorization of fabrics. Chemical modification of enzymes can provide a powerful tool to change the adsorption behaviour of enzymes on water insoluble polymers. Polyethylene glycol (PEG) was covalently attached onto a laccase from Trametes hirsuta. Different molecular weights of the synthetic polymer were tested in terms of adsorption behaviour and retained laccase activity. Covalent attachment of PEG onto the laccase resulted in enhanced enzyme stability while with increasing molecular weight of attached PEG the substrate affinity for the laccase conjugate decreased. The activity of the modified laccases on fibre bound dye was drastically reduced decreasing the adsorption of the enzyme on various fabrics. Compared to the 5 kDa PEG laccase conjugate (K/S value 47.60

Characterization of an Alkali- and Halide-Resistant Laccase Expressed in E. coli: CotA from <i>Bacillus clausii</i>

The limitations of fungal laccases at higher pH and salt concentrations have intensified the search for new extremophilic bacterial laccases. We report the cloning, expression, and characterization of the bacterial cotA from Bacillus clausii, a supposed alkalophilic ortholog of cotA from B. subtilis. Both laccases were expressed in E. coli strain BL21(DE3) and characterized fully in parallel for strict benchmarking. We report activity on ABTS, SGZ, DMP, caffeic acid, promazine, phenyl hydrazine, tannic acid, and bilirubin at variable pH. Whereas ABTS, promazine, and phenyl hydrazine activities vs. pH were similar, the activity of B. clausii cotA was shifted upwards by ~0.5-2 pH units for the simple phenolic substrates DMP, SGZ, and caffeic acid. This shift is not due to substrate affinity (K(M)) but to pH dependence of catalytic turnover: The k(cat) of B. clausii cotA was 1 s⁻¹ at pH 6 and 5 s⁻¹ at pH 8 in contrast to 6 s⁻¹ at pH 6 and 2 s⁻¹ at pH 8 for of B. subtilis cotA. Overall, k(cat)/K(M) was 10-fold higher for B. subtilis cotA at pH(opt). While both proteins were heat activated, activation increased with pH and was larger in cotA from B. clausii. NaCl inhibited activity at acidic pH, but not up to 500-700 mM NaCl in alkaline pH, a further advantage of the alkali regime in laccase applications. The B. clausii cotA had ~20 minutes half-life at 80°C, less than the ~50 minutes at 80°C for cotA from B. subtilis. While cotA from B. subtilis had optimal stability at pH~8, the cotA from B. clausii displayed higher combined salt- and alkali-resistance. This resistance is possibly caused by two substitutions (S427Q and V110E) that could repel anions to reduce anion-copper interactions at the expense of catalytic proficiency, a trade-off of potential relevance to laccase optimization