Electric dipole moments of nitric acid-water complexes measured by cluster beam deflection

Water clusters embedding a nitric acid molecule HNO3(H2O)_{n=1-10} are investigated via electrostatic deflection of a molecular beam. We observe large paraelectric susceptibilities that greatly exceed the electronic polarizability, revealing the contribution of permanent dipole moments. The moments derived from the data are also significantly higher than those of pure water clusters. An enhancement in the susceptibility for n=5,6 and a rise in cluster abundances setting in at n=6 suggest that dissociation of the solvated acid molecule into ions takes place in this size range.Comment: Proceedings of ISACC 2009, The Fourth International Symposium "Atomic Cluster Collisions: structure and dynamics from the nuclear to the biological scale" (AIP Conference Proceedings

Magnetic Moments and Adiabatic Magnetization of Free Cobalt Clusters

Magnetizations and magnetic moments of free cobalt clusters CoN (12\u3c N \u3c200) in a cryogenic (25 K ≤ T ≤ 100 K) molecular beam were determined from Stern-Gerlach deflections. All clusters preferentially deflect in the direction of the increasing field and the average magnetization resembles the Langevin function for all cluster sizes even at low temperatures. We demonstrate in the avoided crossing model that the average magnetization may result from adiabatic processes of rotating and vibrating clusters in the magnetic field and that spin relaxation is not involved. This resolves a longstanding problem in the interpretation of cluster beam deflection experiments with implications for nanomagnetic systems in general

Measurement of magnetic moments of free Bi\u3ci\u3eN\u3c/i\u3eMn\u3ci\u3eM\u3c/i\u3e clusters

Magnetic properties of free BiNMnM clusters (N=2–20, M=0–7) are determined from Stern-Gerlach deflections at low temperature (46.5 K). Pure bismuth clusters with odd number of atoms exhibit paramagnetic deflections. The addition of manganese atoms produces a ferromagnetic response which is strongly size dependent. Certain combinations have very large magnetic moments such as Bi5Mn3, Bi9 Mn4, Bi10Mn5, and Bi12Mn6

Spin Uncoupling in Free Nb Clusters: Support for Nascent Superconductivity

Molecular beam Stern-Gerlach deflection measurements on Nb clusters (NbN, N \u3c100) show that at very low temperatures the odd-N clusters deflect due to a single unpaired spin that is uncoupled from the cluster. At higher temperatures the spin is coupled and no deflections are observed. Spin uncoupling occurs concurrently with the transition to the recently found ferroelectric state, which has superconductor characteristics [Science 300, 1265 (2003)]. Spin uncoupling (also seen in V, Ta, and Al clusters) is analogous to the reduction of spin-relaxation rates observed in bulk superconductors below Tc

Magnetic Enhancement in Cobalt-Manganese Alloy Clusters

Magnetic moments of CoNMnM and CoNVM clusters (N ≤ 60; M ≤ N/3) are measured in molecular beams using the Stern-Gerlach deflection method. Surprisingly, the per atom average moments of CoNMnM clusters are found to increase with Mn concentration, in contrast to bulk CoMn. The enhancement with Mn doping is found to be independent of cluster size and composition in the size range studied. Meanwhile, CoNVM clusters show reduction of average moments with increasing V doping, consistent with what is expected in bulk CoV. The results are discussed within the virtual bound states model

Artificial Intelligence and Human Resources Management: A Bibliometric Analysis

Artificial Intelligence (AI) is increasingly present in organizations. In the specific case of Human Resource Management (HRM), AI has become increasingly relevant in recent years. This article aims to perform a bibliometric analysis of the scientific literature that addresses in a connected way the application and impact of AI in the field of HRM. The scientific databases consulted were Web of Science and Scopus, yielding an initial number of 156 articles, of which 73 were selected for subsequent analysis. The information was processed using the Bibliometrix tool, which provided information on annual production, analysis of journals, authors, documents, keywords, etc. The results obtained show that AI applied to HRM is a developing field of study with constant growth and a positive future vision, although it should also be noted that it has a very specific character as a result of the fact that most of the research is focused on the application of AI in recruitment and selection actions, leaving aside other sub-areas with a great potential for application

Metastability of Free Cobalt and Iron Clusters: A Possible Precursor to Bulk Ferromagnetism

Homonuclear cobalt and iron clusters CoN and FeN measured in a cryogenic molecular beam exist in two states with distinct magnetic moments (μ), polarizabilities, and ionization potentials, indicating distinct valences. The μ is approximately quantized: μN ~ 2NμB in the ground states and μN* ~ NμB in the excited states for Co; μN ~ 3N μB and μN * ~ NμB for Fe. At a large size, the average μ of the two states converges to the bulk value with diminishing ionization potential differences. The experiments suggest localized ferromagnetism in the two states and that itinerant ferromagnetism emerges from their superposition

Non-classical dipoles in cold niobium clusters

Electric deflections of niobium clusters in molecular beams show that they have permanent electric dipole moments at cryogenic temperatures but not higher temperatures, indicating that they are ferroelectric. Detailed analysis shows that the deflections cannot be explained in terms of a rotating classical dipole, as claimed by Anderson et al. The shapes of the deflected beam profiles and their field and temperature dependences indicates that the clusters can exist in two states, one with a dipole and the other without. Cluster with dipoles occupy lower energy states. Excitations from the lower states to the higher states can be induced by low fluence laser excitation. This causes the dipole to vanish.Comment: 25 pages, 7 figure

SOC-V-11 New serum miRNA biomarkers to predict liver steatosis by valproic acid in paediatric epileptic patients

Depakine (Valproate, VPA) has been the first line, most-frequently prescribed, anti-epileptic drug in children for the past 50 years. Idiosyncratic hepatotoxicity (iDILI) by VPA has been demonstrated in several case reports, where microvesicular liver steatosis was the most frequent feature. Moreover, more than half of VPA-treated patients could have silent fatty liver as demonstrated by ultrasounds. Extensive experimental studies support that VPA has a high potential to induce steatosis in hepatocytes. However, there is an apparent lack of significant hepatic problems in the Neuropediatric Units, despite transaminitis is not uncommon. One of the reasons could be that iDILI and liver steatosis diagnosis lack specific biomarkers. Thus, it is likely that a relevant number of children under VPA treatment may have a significant, but sub-clinical, hepatosteatosis