16 research outputs found
Sulphur Kβ emission spectra reveal protonation states of aqueous sulfuric acid
In this paper we report an X-ray emission study of bulk aqueous sulfuric acid. Throughout the range of molarities from 1 M to 18 M the sulfur K beta emission spectra from H2SO4 (aq) depend on the molar fractions and related deprotonation of H2SO4. We compare the experimental results with results from emission spectrum calculations based on atomic structures of single molecules and structures from ab initio molecular dynamics simulations. We show that the S K beta emission spectrum is a sensitive probe of the protonation state of the acid molecules. Using non-negative matrix factorization we are able to extract the fractions of different protonation states in the spectra, and the results are in good agreement with the simulation for the higher part of the concentration range.Peer reviewe
Multiple-perspective performance analysis of dairy production systems in Slovenia
The paper illustrates synergies between the socio-economic and emergy evaluation of
agricultural activity by studying the dairy sector in Slovenia. Evaluation was performed on
nine farm types, representing the diversity of the country's dairy sector. Results indicate that
socio-economic evaluation favours larger conventional systems. Emergy analysis however,
favours organic farms, which better exploit local resources and put less stress to the local
environment. Socio-economic and emergy indicators show that small conventional farms are
the poorest performers overall. Analysis of emergy flows reveals a high dependency of all
farm types from the wider socio-economic system, suggesting a limited scope to improve
their sustainability
On Detecting Note Onsets in Piano Music
This paper presents a brief overview of our researches in the use of connectionist systems for transcription of polyphonic piano music and concentrates on the issue of onset detection in musical signals. We propose a new technique for detecting onsets in a piano performance. The technique is based on a combination of a bank of auditory filters, a network of integrateand -fire neurons and a multilayer perceptron. Such structure introduces several advantages over the standard peak-picking onset detection approach and we present its performance on several synthesized and real piano recordings. Results show that our approach represents a viable alternative to existing onset detection algorithms
The influence of cytotoxic drugs on the immunophenotype of blast cells in paediatric B precursor acute lymphoblastic leukaemia
Flow cytometry plays is important in the diagnosis of acute lymphoblastic leukaemia (ALL) and when antigen-specific immunotherapy is indicated. We have investigated the effects of prednisolone, vincristine, daunorubicin, asparaginase and methotrexate on the antigen expression on blast cells that could influence the planning of antigen-specific therapy as well as risk-based treatment assignment
Characterization of Electrochemical Processes in Metal–Organic Batteries by X-ray Raman Spectroscopy
X-ray Raman spectroscopy (XRS) is an emerging spectroscopic technique that utilizes inelastic scattering of hard X-rays to study X-ray absorption edges of low Z elements in bulk material. It was used to identify and quantify the amount of carbonyl bonds in a cathode sample, in order to track the redox reaction inside metal–organic batteries during the charge/discharge cycle. XRS was used to record the oxygen K-edge absorption spectra of organic polymer cathodes from different multivalent metal–organic batteries. The amount of carbonyl bond in each sample was determined by modeling the oxygen K-edge XRS spectra with the linear combination of two reference compounds that mimicked the fully charged and the fully discharged phases of the battery. To interpret experimental XRS spectra, theoretical calculations of oxygen K-edge absorption spectra based on density functional theory were performed. Overall, a good agreement between the amount of carbonyl bond present during different stages of battery cycle, calculated from linear combination of standards, and the amount obtained from electrochemical characterization based on measured capacity was achieved. The electrochemical mechanism in all studied batteries was confirmed to be a reduction of double carbonyl bond and the intermediate anion was identified with the help of theoretical calculations. X-ray Raman spectroscopy of the oxygen K-edge was shown to be a viable characterization technique for accurate tracking of the redox reaction inside metal–organic batteries