A5086233470- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Analytical chemistry methods development
- Astronomy and Astrophysical Research
- Radioactive element chemistry and processing
- Gamma-ray bursts and supernovae
- Isotope Analysis in Ecology
- History and Developments in Astronomy
- Historical Astronomy and Related Studies
- Astro and Planetary Science
- Adaptive optics and wavefront sensing
- Galaxies: Formation, Evolution, Phenomena
- Extraction and Separation Processes
- CCD and CMOS Imaging Sensors
- Advanced Polymer Synthesis and Characterization
- Mass Spectrometry Techniques and Applications
- Innovative Microfluidic and Catalytic Techniques Innovation
- Astrophysics and Star Formation Studies
- Calibration and Measurement Techniques
- Historical Geography and Cartography
- Space Satellite Systems and Control
- Polymer Science and PVC
- Nuclear Physics and Applications
- Petroleum Processing and Analysis
- Advanced Bandit Algorithms Research
Federal Institute For Materials Research and Testing
2017-2025
Humboldt-Universität zu Berlin
2017-2021
Leibniz Institute for Analytical Sciences - ISAS
2017-2018
Universidad de Granada
2011
University of the Andes
2010
Instituto Venezolano de Investigaciones Científicas
2005-2009
Centro de Investigación Docencia y Consultoria Administrativa
2009
Universidad Nacional Autónoma de México
2006-2008
Universidad de Zaragoza
2002-2005
University of the Basque Country
1994-1999
We have measured the periods and light curves of 148 RR Lyrae variables from V = 13.5 to 19.7 first 100 deg2 Quasar Equatorial Survey Team survey. Approximately 55% these stars belong clump detected earlier by Sloan Digital Sky Survey. According our measurements, this feature has ~10 times background density halo stars, spans at least 375 35 in α δ (≥30 ≥3 kpc), lies ~50 kpc Sun, a depth along line sight ~5 (1 σ). These properties are consistent with recent models that suggest it is tidal...
Abstract This work presents the development and certification of world’s first certified reference material (CRM), BAM-S014, for a lithium nickel manganese cobalt oxide (LiNi 0.33 Mn Co O 2 or Li-NMC 111) cathode material—an integral component in high-energy-density lithium-ion batteries that power electric vehicles (EVs), portable electronics, stationary energy storage systems. By providing mass fractions 11 elements, this CRM addresses critical need accurate traceable elemental analysis,...
With the 1 m Schmidt telescope of Llano del Hato Observatory and QUEST CCD camera, 380 deg2 sky have been surveyed for RR Lyrae variables in a band 23 wide declination (centered at δ = -1°) covering right ascensions from 41 to 61 80 170. The bright limit (due saturation) faint are V ∼ 13.5 ∼19.7, respectively, which correspond ∼4 ∼60 kpc Sun. We present catalog positions, amplitudes, mean magnitudes, periods, light curves 498 that identified this region sky. majority these stars (86%) new...
Our multi-epoch survey of ∼20 deg2 the Canis Major (CMa) overdensity has detected only 10 RR Lyrae stars (RRLS). We show that this number is consistent with expected from Galactic halo and thick disk populations alone, leaving no excess can be attributed to dwarf spheroidal (dSph) galaxy some authors have proposed as origin CMa overdensity. If resembles dSph satellites Milky Way (MW) M31 putative MV ∼ −14.5, our should several tens RRLS. Even if ≲ −12, ≳10, which not observed. Either old...
In this study, we employed nitrogen microwave inductively coupled atmospheric-pressure plasma (MICAP) combined with quadrupole mass spectrometry (MS) and a liquid sample introduction system to analyze heavy metals in soils.
In this study, we demonstrate the applicability of nitrogen microwave inductively coupled atmospheric pressure mass spectrometry (MICAP-MS) for Ca, Fe, and Se quantification in human serum using isotope dilution (ID) analysis. The matrix tolerance MICAP-MS Na was investigated, revealing that high levels can suppress signal intensity. This suppression is likely due to plasma loading space charge effect. Moreover,
This study introduces an improved spectrometric method with enhanced precision to determine isotope ratios in geological samples without chromatographic separation. Firstly, the improvement is achieved by increasing spectral resolution of spectrometer applied well-known high-resolution continuum source atomic absorption spectrometry (HR-CS-AAS). The resulting resolving power and linear dispersion upgraded setup, which denoted following as HR + CS-AAS, well adapted line widths Li components...
An alternative method for lithium isotope amount ratio analysis based on a combination of high-resolution atomic absorption spectrometry and spectral data by machine learning (ML) is proposed herein. It the well-known shift approximately 15 pm electronic transition 22P←22S at around wavelength 670.8 nm, which can be measured state-of-the-art continuum source graphite furnace spectrometry. For analysis, scalable tree boosting ML algorithm (XGBoost) was employed calibrated using set samples...
The entire process involving the determination of Cl by molecular emission detection in Laser-Induced Breakdown Spectroscopy (LIBS) is thoroughly studied this paper. This critical evaluation considers how spectra are normalized, interferences from other species signals removed, and signal integration applied. Moreover, a data treatment protocol proposed to achieve reliable accurate CaCl spectral signal, not requiring use more complex numerical approaches. Calcium chloride dihydrate...
We investigated the performance of nitrogen microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MICAP-MS) under matrix effects and its applicability to trace element analysis in steels.
Abstract The high solids emulsion copolymerization of vinyl acetate and veova 10 was studied in a continuous loop reactor stirred tank (CSTR) an attempt to elucidate the similarities differences between these reactors. Reactions were carried out under comparable conditions, namely, similar macromixing same feed composition space time. behavior both reactors almost when heat generation rate low; otherwise, thermal runaway occurred CSTR whereas temperature easily controlled. © 1995 John Wiley...
The mechanism of action zirconium permanent modifiers on graphite surfaces was investigated in order to understand its influence the analytical signal atomic and molecular absorption spectrometry (AAS/MAS).
The effect of several operation conditions (temperature, residence time, recycle ratio, initiator concentration and emulsifier concentration) on the performance a continuous loop reactor during redox initiated emulsion copolymerization vinyl acetate Veova 10 was investigated. study carried out under industrial-like conditions, namely, high solids content latexes (55wt%) conversions (~90%). Both polymerization mechanisms practical issues such as production rate product quality are discussed.
We have designed, constructed, and put into operation a large‐area CCD camera that covers large fraction of the image plane 1 m Schmidt telescope at Llano del Hato in Venezuela. The consists 16 devices arranged 4 × mosaic covering 23 35 sky. CCDs are 2048 LORAL with 15 μm pixels. is optimized for drift‐scan photometry objective‐prism spectroscopy. design considerations, construction features, performance parameters described following paper.
We describe the discovery circumstances and photometric properties of 2000 EB173, now one brightest trans-Neptunian objects (TNOs) with opposition magnitude mR = 18.9 also largest Plutinos, found drift-scanning camera Quasar Equatorial Survey Team, attached to 1 m Schmidt telescope National Observatory Venezuela. measure B-V 0.99 ± 0.14 V-R 0.57 0.05, a red color observed for many fainter TNOs. At our limit 20.1 0.20, single detection reveals sky density 0.015 TNOs per square degree (the...
The QUEST (QUasar Equatorial Survey Team) Phase 1 camera has collected multibandpass photometry on a large strip of high Galactic latitude sky over period 26 months. This robust data set been reduced and nightly catalogs compared to determine the photometric variability ensemble objects. Subsequent spectroscopic observations have confirmed subset variables as quasars, previously reported. paper reports details reduction analysis pipeline presents multiple bandpass light curves for 198,213...
By observing the high galactic latitude equatorial sky in drift scan mode with QUEST (QUasar Equatorial Survey Team) Phase 1 camera, multi-bandpass photometry on a large strip of sky, resolved over range time scales (from hourly to biennially) has been collected. A robust method ensemble revealed those objects within region that fluctuate brightness at statistically significant level. Subsequent spectroscopic observations subset varying easily discriminated quasars from stars. For 13-month...
The therapeutic dose of lithium (Li) compounds, which are widely used for the treatment psychiatric and hematologic disorders, is close to its toxic level; therefore, drug monitoring protocols mandatory. Herein, we propose a fast, simple, low-cost analytical procedure traceable determination Li concentration in human serum, based on isotope dilution through partially resolved shift electronic transition around 670.80 nm using commercially available high-resolution continuum source graphite...