A discharge adaptor interface for use in liquid chromatography/mass spectrometry

A discharge adaptor, composed of a metal casing and platinum (Pt) wire needle, was directly attached to an electrospray ionization (ESI) probe tip, to transform the ionization into atmospheric pressure chemical ionization (APCI). Six generic drugs were analyzed with the developed discharge adaptor (DA) and two commercial interfaces. The DA interface produced more intense radical anions, [M]^.–, and less sodium adduct ions, [M + Na]⁺, than the ESI interface, whereas almost the same molecular ions were detected as the APCI interface. The effects of solvent and desolvation gas flow in the DA interface were similar to those in the ESI interface, but differed from those in the APCI interface. Better sensitivity of the tested drugs was obtained relative to the commercial APCI interface. For human plasma samples, the DA interface also demonstrated good tolerance to plasma matrices, linearity from 5 or 20 to 500 ng/mL (r² > 0.99) and ruggedness. Copyright © 2011 John Wiley & Sons, Ltd.     

Untersuchung von Wasser

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Schwefel, Sulfat, Sulfid, Hydrosulfid

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Synthesis of novel benzoxathiazepine-1,1-dioxides by means of a one-pot multicomponent reaction

A simple one-pot synthesis of benzoxathiazepine-1,1-dioxides is described. Increased yields are afforded when suitable substituents are present in one of the starting materials. These additional substituents also provide a handle for further functionalization.     

Three‐dimensional quadratic nonconforming brick element

A new nonconforming brick element with quadratic convergence for the energy norm is introduced. The nonconforming element consists of on a cube [?1,1]³, and 14 degree of freedom (DOF). Two types of DOF are introduced. One consists of the value at the eight vertices and six face‐centroids and the other consists of the value at the eight vertices and the integration value of six faces. Error estimates of optimal order are derived in both broken energy and norms for second‐order elliptic problems. If a genuine hexahedron, which is not a parallelepiped, is included in the partition, the proposed element is also convergent, but with a lower order. Copyright © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 30: 158–174, 2014     

Penetration force measurement of thin plates by laser doppler anemometry

An experimental method is developed by applying laser-Doppler anemometry (LDA) to measure the velocity history of a projectile impact on a target. The force history was obtained by assuming the projectile to be rigid and by differentiating a polynomial which best fitted the obtained velocity data. This method was then applied to the impact of a hemispherically tipped striker on 1-mm thick aluminum plates. The initial velocity of the projectile ranged from several m/s to 93.5 m/s. When these velocities were low enough not to produce cracks on the plate, double-force peaks were observed in each test, and the value corresponding to the higher peak was proportional to the initial velocity of the projectile. Further, this peak force occurred when the projectile just started to rebound, and spring-back behavior of the plate always occurred. Once the cracks on the target started to form, the peak impact force dropped, and the double-peak phenomenon disappeared. It was also found that the peak force was at approximately the same level for impact speeds above the ballistic limit of the plate. On the other hand, a power law was found to perfectly fit the relationship between the absorbed kinetic energy and the initial velocity of the projectile when it was lower than the ballistic limit.     

Seaweed Chlorophyll on the Light‐electron Efficiency of DSSC

Four different seaweed extracts were employed as the dyes of dye sensitized solar cells (DSSCs) to investigate the light‐electron efficiency. The sensitizers, extracted from Nannochloropsis spp., Tetraselmis spp., Gracilaria spp., and Ulvales spp., showed their light‐electronic transfer ability in different light intensities. Among them, Ulvales output a higher light‐voltage, about 0.4 V. The output voltage increased when light intensity increased. Gracilaria extract produced a higher output voltage at 35 Lux, but its output voltage decreased over 500 Lux. The sensitizers extracted from these seaweeds had monochromatic incident photon‐to‐electron conversion efficiencies (IPCE) between 23‐61% in 220‐260 nm wavelengths. Among them, Ulvales output higher IPCE than Tetraselmis and Nannochloropsis. SEM analysis of DSSC surfaces revealed that the efficiency of seaweed DSSCs was governed by chlorophyll size. The chlorophyll particle size of Ulvales spp. was the largest. The chlorophyll particle size of Gracilaria spp. was the smallest and yielded the lowest IPCE.     

A discharge adaptor interface for use in liquid chromatography/mass spectrometry

A discharge adaptor, composed of a metal casing and platinum (Pt) wire needle, was directly attached to an electrospray ionization (ESI) probe tip, to transform the ionization into atmospheric pressure chemical ionization (APCI). Six generic drugs were analyzed with the developed discharge adaptor (DA) and two commercial interfaces. The DA interface produced more intense radical anions, [M]˙?, and less sodium adduct ions, [M + Na]?, than the ESI interface, whereas almost the same molecular ions were detected as the APCI interface. The effects of solvent and desolvation gas flow in the DA interface were similar to those in the ESI interface, but differed from those in the APCI interface. Better sensitivity of the tested drugs was obtained relative to the commercial APCI interface. For human plasma samples, the DA interface also demonstrated good tolerance to plasma matrices, linearity from 5 or 20 to 500 ng/mL (r2 > 0.99) and ruggedness.     

Spatiotemporal dynamics in Rayleigh band of photonic quantum ring laser

Spatiotemporal dynamic simulations are carried out for the carrier-field interactions of photonic quantum ring lasers of three dimensional (3D) whispering cave modes (WCMs). We observe quantum wires-like carrier re-distributions naturally formed in the Rayleigh band region of the active quantum well plane. Apart from the regular two dimensional (2D) whispering gallery mode (WGM), the 3D WCM’s major polarization state favors a strong carrier-photon coupling for the carriers in the Rayleigh band, such that the powerful transient coupling generates photonic quantum rings (PQRs), or concentric quantum rings with a half-wavelength pitch of imminently recombinant carriers, i.e., a photonic quantum corral effect. This feature is responsible for the low threshold currents and thermally stable spectra, which opens the way for easy optical mega-pixel (‘Omega’) chip fabrications.