Search results for "Desorption"
showing 10 items of 340 documents
ESD of nonthermal halogen atoms from In-doped (001) KBr
1995
Abstract We have measured the kinetic energy distributions of neutral halogen atoms emitted due to electron-stimulated desorption (ESD) from In-doped (001)KBr single crystals. The concentration of In+ in investigated samples varied between 1017 and 1020 particles/cm3. The measurements were performed at target temperature of 150°C. In all cases the energy spectra consist of two peaks. The distribution of low-energy particles can be described by the thermal (Maxwellian) energy spectrum. Particles contributing to the second peak have nonthermal kinetic energies. The emission of halogen atoms having nonthermal energies decreases with an increase in the concentration of In impurities. At the sam…
Facility for thermal helium desorption (THDS) measurements
1995
Abstract We describe a thermal helium desorption spectrometer, built at the Department of Physics, University of Jyvaskyla, which will be used in investigations of crystal defects generated by keV range heavy ion bombardment. The helium desorption method and its requirements are reviewed briefly. The structure of the facility itself is presented in detail. The efficiency and the operation of the apparatus is discussed.
Structure, tritium depth profile and desorption from 'plasma-facing' beryllium materials of ITER-Like-Wall at JET
2017
This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement No 633053 . The views and opinions expressed herein do not necessarily reflect those of the European Commission.
Serum proteome profiling of primary breast cancer indicates a specific biomarker profile.
2011
Non-invasive biomarkers for early breast cancer detection are urgently needed, as the risk of recurrent morbidity and mortality is closely related to the stage of the disease at the time of primary surgery. Currently, there are no established clinical biomarkers for breast cancer. Evaluation of protein expression patterns in body fluids using proteomic technologies can be used to discover new biomarkers for the detection of breast cancer. The aim of this study was to identify a biomarker signature identifying primary non-metastatic breast cancer and healthy controls. We screened 91 serum samples including 45 breast cancer patients and 46 healthy women using a proteomic approach. We found 14…
Comparison of computational and experimental saturation vapor pressures of α-pinene + O<sub>3</sub> oxidation products
2021
Abstract. Accurate information on gas-to-particle partitioning is needed to model secondary organic aerosol formation. However, determining reliable saturation vapor pressures of atmospherically relevant multifunctional organic compounds is extremely difficult. We estimated saturation vapor pressures of α-pinene ozonolysis derived secondary organic aerosol constituents using FIGAERO-CIMS experiments and COSMO-RS theory. We found a good agreement between experimental and computational saturation vapor pressures for molecules with molar masses around 190 g mol−1 and higher, most within a factor of 3 comparing the average of the experimental vapor pressures and the COSMO-RS estimate of the iso…
SELDI-TOF-MS ProteinChip array profiling of tears from patients with dry eye.
2005
Protein and peptides in tears play an important role in ocular surface diseases. In previous studies, changes have been demonstrated in the electrophoretic protein profiles of patients with dry eye. The purpose of this work was to determine the usefulness of surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS) ProteinChip Array (Ciphergen Biosystems, Inc., Fremont, CA) technology for the automated analysis of proteins and peptides in tear fluid.Patients with dry eye (DRY, n = 88) and healthy subjects (CTRL, n = 71) were examined. Their tear proteins were analyzed using SELDI-TOF-MS ProteinChip Arrays with three different chromatographic surfaces (CM10…
Primary structure and unusual carbohydrate moiety of functional unit 2-c of keyhole limpet hemocyanin (KLH)
1999
Abstract The complete amino acid sequence of the Megathura crenulata hemocyanin functional unit KLH2-c was determined by direct sequencing and matrix-assisted laser desorption ionization mass spectrometry of the protein, and of peptides obtained by cleavage with EndoLysC proteinase, chymotrypsin and cyanogen bromide. This is the first complete primary structure of a functional unit c from a gastropod hemocyanin. KLH2-c consists of 420 amino acid residues. Circular dichroism spectra indicated approx. 31% β-sheet and 29% α-helix contents. A multiple sequence alignment with other molluscan hemocyanin functional units revealed average identities between 41 and 49%, but 55% in case of Octopus he…
Investigation of various shellac grades: additional analysis for identity.
2009
Background: A number of different grades of shellac are commercially available and most of them are known only as generic shellac and are not further differentiated. The investigated grades of shellac in this study are based on different insect strains, host trees, refining methods, and products from different suppliers. Method: The Gardner/Iodine color values of alcoholic and aqueous solutions of the various shellac grades were measured. Glass transition temperatures and pKa-values were determined. To assess chemical differences in the tested shellac grades, MALDI-TOF analysis was performed. Results: Differences were found in color, TG, and pKa-values and in the mass spectra by MALDI-TOF a…
Validation of a two-dimensional modeling of an externally irradiated slurry photoreactor
2015
Abstract A two-dimensional model describing the behavior of a batch cylindrical photoreactor has been validated through a series of photocatalytic reactivity runs. The light intensity radiation field produced by 1–6 external UV fluorescent lamps was modeled together with Langmuir–Hinshelwood kinetics and 4-nitrophenol (NP) and Degussa P25 TiO 2 were used as the probe molecule and the catalyst, respectively. The experiments were carried out under different conditions of light intensity, photocatalyst amount and substrate concentration. The model parameters were the kinetic constant of substrate adsorption, desorption and degradation and the exponent of the power law expressing the kinetics d…
Resonance lonization mass spectroscopy with a pulsed thermal atomic beam
1987
Resonance ionization mass spectroscopy (RIMS) and pulsed-laser induced desorption (PLID) have been combined for ultrasensitive detection and spectroscopy of very small samples of refractive elements. The method has been tested and applied to laser spectroscopy of 5×109 atoms (1.5 pg) of195Au (T1/2= 183d) implanted at the ISOLDE online mass separator with 60 keV into graphite. A pulsed thermal atomic beam was formed by laser desorption with a 10 ns Nd∶Yag laser pulse. Subsequently the atoms were photoionized in a three-colour, three-step resonant excitation to an autoionizing state. The selectivity was enhanced by a time-of-flight measurement of the photo ions. In resonance, one ion was dete…