Ultrasensitive Molecule Detection Based on Infrared Metamaterial Absorber with Vertical Nanogap

Surface-enhanced infrared absorption (SEIRA) spectroscopy is a powerful methodology for sensing and identifying small quantities of analyte molecules via coupling between molecular vibrations and an enhanced near-field induced in engineered structures. A metamaterial absorber (MA) is proposed as an efficient SEIRA platform; however, its efficiency is limited because it requires the appropriate insulator thickness and has a limited accessible area for sensing. SEIRA spectroscopy is proposed using an MA with a 10 nm thick vertical nanogap, and a record-high reflection difference SEIRA signal of 36% is experimentally achieved using a 1-octadecanethiol monolayer target molecule. Theoretical and experimental comparative studies are conducted using MAs with three different vertical nanogaps. The MAs with a vertical nanogap are processed using nanoimprint lithography and isotropic dry etching, which allow cost-effective large-area patterning and mass production. The proposed structure may provide promising routes for ultrasensitive sensing and detection applications

Fluoreszenzspektroskopische Untersuchungen an Bianthryl-Derivaten im freien Ueberschallduesenstrahl

SIGLEAvailable from TIB Hannover: MA 6914 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Determination of local stress-strain properties of spot welded joints using the instrumented indentation test

Determination of Local Stress-Strain Properties of Spot Welded Joints Using the Instrumented Indentation Test. The local strength properties in the region of weld joints are essential for their resistance to mechanical stress. In contrast to an alternative method of determining the local stress strain behaviour i.e. the preparation intensive, destructive micro tensile test the instrumented indentation test (ITT) provides gradients of strength properties with excellent local resolution. Two methods of determining true stress strain curves from cyclic indentation test have been used in order to investigate the strength behaviour in the region of resistance spot welded joints (region of base metal and weld nugget) of two high strength steels, a TRIP steel, and a martensitic steel and on the other hand a mild steel. Exemplary for the TRIP steel the results were compared and discussed with stress-strain-curves obtained by tensile tests on specimens made of the base metal and on specimens which were heat-treated corresponding to the welding process

Particularities of optical pumping effects in cold and ultra-slow beams of Na and Cs in the case of cyclic transitions

The time-dependent population dynamics of hyperfine (HF) levels of n2p3/2 states is examined for cyclic transitions in alkali atoms. We study a slow and cold atomic beam of Na (n = 3) and Cs (n = 6), taking into account the long interaction time of light with atoms (~200 μs) inside the resonant laser beam. Simple analytical expressions for the populations of the excited states and for the intensities of the absorption lines are derived for a three-level system model. We show that at moderate pump laser power the mixing of HF levels is sufficient to form a flow of population from a cyclic transition to partially open transitions. We discuss various phenomena associated with the evolution of optical pumping that cannot be explained by general analysis of two-level system model

Drug resistance without drug selection: polymorphism in leuS confers reduced susceptibility 1 to GSK2251052 in a clinical isolate of Staphylococcus aureus

GSK2251052 is a broad-spectrum antibacterial inhibitor of leucyl tRNA-synthetase (LeuRS) that has been evaluated in Phase II clinical trials. Here we report the identification of a clinical isolate of Staphylococcus aureus that exhibits reduced susceptibility to GSK2251052 without prior exposure to the compound, and demonstrate that this phenotype is attributable to a single amino acid polymorphism (P329) within the editing domain of LeuRS

Environmental impact statement: Via Baltica, section Lilaste-Skulte. With annexes Final report

With CD-ROM. Published in 2 vols.Available from TIB Hannover: RN 8908(2000,400,1): RN 8908(2000,400,2) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Berlin (Germany); Ministry of Transport and Communication, Riga (Latvia)DEGerman