19 research outputs found
CMOS compatible integrated all-optical radio frequency spectrum analyzer
We report an integrated all-optical radio frequency spectrum analyzer based on a ~4cm long doped silica glass waveguide, with a bandwidth greater than 2.5 THz. We use this device to characterize the intensity power spectrum of ultrahighrepetition rate mode-locked lasers at repetition rates up to 400 GHz, and observe dynamic noise related behavior not observable with other technique
The Electron Capture in Ho Experiment - a Short Update
The definition of the absolute neutrino mass scale is one of the main goals of the Particle Physics today. The study of the end-point regions of the ÎČ- and electron capture (EC) spectrum offers a possibility to determine the effective electron (anti-)neutrino mass in a completely model independent way, as it only relies on the energy and momentum conservation.
The ECHo (Electron Capture in 163Ho) experiment has been designed in the attempt to measure the effective mass of the electron neutrino by performing high statistics and high energy resolution measurements of the 163 Ho electron capture spectrum. To achieve this goal, large arrays of low temperature metallic magnetic calorimeters (MMCs) implanted with with 163Ho are used. Here we report on the structure and the status of the experiment
Micro to nano: Surface size scale and superhydrophobicity
This work looks at the fundamental question of how the surface mobility of drops in the composite state is related to the size scale of the roughness features of the surface. To this end, relevant literature is first reviewed and the important terms are clarified. We then describe and discuss contact and roll-off angle measurements on a set of hydrophobicized silicon post surfaces for which all parameters except for the surface size scale were held constant. It was found that a critical transition from âsticky superhydrophobicâ (composite state with large contact angle hysteresis) to âtruly superhydrophobicâ (composite state with low hysteresis) takes place as the size of the surface features reaches 1 ÎŒm
Development of a Fluorescent Microfluidic Device Based on Antibody Microarray Read-Out for Therapeutic Drug Monitoring of Acenocoumarol
The development of a proof-of-concept point-of-care (PoC) device for the determination of oral anticoagulants determination is presented. Acenocoumarol (ACL) is prescribed to prevent certain cardiovascular diseases related to the prevention of deep vein thrombosis, pulmonary embolism, myocardial infarction, and stroke. Oral anticoagualant treatment (OAT) represents a population of 2% under treatment which has expenditures about $ 144 million in 2011. The main drawback for OAT is the associated narrow therapeutic window and the unpredictable dose-response relationship, which is one of the main causes for visiting the emergency room at the hospitals. In a previous work, family antibodies were produced for the simultaneous detection of ACL and warfarin (W) depending on the area of application. It was developed in different formats, indirect and direct, either with similar detectabilities and both assays quantifying the oral anticoagulants with high accuracy and reproducibility. We present the implementation of the already developed immunochemical method to a point-of-care (PoC) device to assist on the patient compliance assessment programs. In order to achieve this goal, a first development was performed implementing ACL ELISA assay into a microarray format with fluorescent read-out. The assay was successfully implemented achieving a LOD of 1.23Â nM of ACL directly measured in human plasma. Then, a fully integrated microfluidic system is developed which incorporates the specific immunoreagents for the detection of ACL. The immunoreagents were attached onto the glass slide in a microarray format. The system is automatic, rapid, sensitive, and disposable that could help clinicians monitor patients under OAT. According to the fluorescent label of the ACL binding, the chip can be easily read with a scanner. The microfluidic system performed good according to the robust and reproducible signals, and subsequently yielded an accurate result.The ICTS âNANOBIOSISâ, and particularly the custom antibody service (CAbS, IQAC-CSIC, and CIBER-BBN) is acknowledged for the assistance and support related to the immunoreagents used in this work.Peer reviewe
Specific Heat of Holmium in Gold and Silver at Low Temperatures
The specific heat of dilute alloys of holmium in gold and in silver plays a major role in the optimization of low temperature microcalorimeters with enclosed , such as the ones developed for the neutrino mass experiment ECHo. We investigate alloys with atomic concentrations of at temperatures between 10 and . Due to the large total angular momentum and nuclear spin of ions, the specific heat of Au:Ho and Ag:Ho depends on the detailed interplay of various interactions, including contributions from the localized 4f electrons and nuclear contributions via hyperfine splitting. This makes it difficult to accurately determine the specific heat of these materials numerically. Instead, we measure their specific heat by using three experimental setups optimized for different concentration and temperature ranges. The results from measurements on six holmium alloys demonstrate that the specific heat of these materials is dominated by a large Schottky anomaly with its maximum at , which we attribute to hyperfine splitting and crystal field interactions. RKKY and dipoleâdipole interactions between the holmium atoms cause additional, concentration-dependent effects. With regard to ECHo, we conclude that for typical operating temperatures of , silver holmium alloys with are suited best
HRSC auf Mars Express - Photogrammetrische und kartographische Auswertungen
Die High Resolution Stereo Camera (HRSC) an Bord der europĂ€ischen Raumsonde Mars Express ist die erste Kamera einer Planetenmission, die speziell fĂŒr photogrammetrische und kartographische Zwecke entwickelt wurde. Seit Januar 2004
liefert die Kamera hochaufgelöste Bilddaten der MarsoberflÀche
in Stereo und in Farbe. Die Bilddaten bergen ein immenses
Potenzial zur Ableitung prÀziser Digitaler GelÀndemodelle
(DGMs) und farbiger Orthophotos sowie zur Herstellung topographischer
und thematischer Karten und weiterer Produkte.
Die Arbeitsgruppe fĂŒr Photogrammetrie und Kartographie
des internationalen HRSC-Forscherteams beschÀftigt sich mit
der systematischen Erstellung von Standardprodukten aus
den Bilddaten und der Verfeinerung dieser Produkte mit dem
Ziel, eine höchstmögliche QualitÀt zu erzielen. Dieser Beitrag
beschreibt einige zur Verfeinerung geeignete Arbeitsschritte
und illustriert den erreichten Stand anhand einer Reihe von
Beispielen
Production, isolation and characterization of radiochemically pure <sup>163</sup>Ho samples for the ECHo-project
Several experiments on the study of the electron neutrino mass are based on high-statistics measurements of the energy spectrum following electron capture of the radionuclide 163Ho. They rely on the availability of large, radiochemically pure samples of 163Ho. Here, we describe the production, separation, characterization, and sample production within the Electron Capture in Holmium-163 (ECHo) project. 163Ho has been produced by thermal neutron activation of enriched, prepurified 162Er targets in the high flux reactor of the Institut Laue-Langevin, Grenoble, France, in irradiations lasting up to 54 days. Irradiated targets were chemically processed by means of extraction chromatography, which allowed separating the formed Ho from the 162Er target-material and from the main byproducts 170Tm and 171Tm, which are co-produced in GBq amounts. Decontamination factors of >500 for Er and of >105 for Tm and yields of 3.6·1016 and 1.2·1018 atoms of 163Ho were obtained, corresponding to a recovery yield of 95 % of Ho in the chemical separation. The Ho-fraction was characterized by means of Îł-ray spectrometry, Inductively-Coupled-Plasma Mass Spectrometry (ICP-MS), Resonance Ionization Mass Spectrometry (RIMS) and Neutron Activation Analysis (NAA). In this process, the thermal neutron capture cross section of 163Ho was measured to ÏHo-163 to Ho-164m= (23±3) b and ÏHo-163 to Ho-164g= (156±9) b for the formation of the two isomers of 164Ho. Specific samples were produced for further purification by mass separation to isolate 163Ho from the Ho-isotope mixture, as needed for obtaining the energy spectrum within ECHo. The partial efficiency for this second separation step is (32±5) %.</p