Mixed Clusters Research Articles

The correlation between chemical effect and segregation behavior in metallic Al liquid

In this work, a study of melt Al1−xMx alloys was carried out by ab initio molecular dynamics (AIMD) simulation within GGA and LDA. Two groups of typical elements Fe, Co, Ni and Cr, V, Ti, showing opposite segregation behaviors in metallic liquid Al, were chosen as the solutes M. The short-range orders (SROs) were analyzed based on the calculation of the static structure factor, pair-correlation function, common neighbor analysis, bond angle distribution function (BADF) and Voronoi polyhedron (VP) analysis. The affinity between unlike species in molten Al1-xMx divides into two groups according to the segregation tendency. The solute atoms with distribution coefficient smaller than 1 (k < 1) prefer to bond with heterogeneous atoms and tend to form medium-range order (MRO) in sharing of common Al atoms, while the solute atoms with distribution coefficient smaller than 1 (k > 1) tend to bond with homogeneous atoms directly. The abundant Voronoi polyhedron (VP) using the solute atom with k < 1 as centered atom is crystal-like cluster (〈0,3,6,0〉 and 〈0,3,6,1〉), whereas that using the solute atom with k > 1 as centered atom is mixed cluster (〈0,2,8,1〉 or 〈0,2,8,2〉). The difference of VP around different solute atoms is mainly caused by the diversity of fraction of different types of bonded pairs of various solute atoms. Our results exhibit that there indeed exist the correlations between the segregation behavior of solutes and the chemical effects in the Al melt. The diffusion of solute elements is not closely related to segregation. This paper also illustrates that the simulations within GGA or LDA yield similar results except for the minor difference. Our work sheds light on the segregation nature of typical solutes from a structural perspective.

Construction of elementary reaction paths of pure and mixed Argon-Xenon clusters : a parallel tempering based study

The problem of studying structural transformation for going from one isomer to another through a transition state is one of considerable interest in chemistry. In this work, we would like to examine the efficiency of the replica exchange Monte Carlo strategy or parallel tempering to search potential energy surface describing the interaction between atoms in noble gas clusters. The systems chosen are both a pure noble gas cluster as well as those formed by two different noble gas entities. Location of minimal structures as well as transition state with the path connecting these three critical points has been carried out for different sizes. To understand the working principles of the parallel tempering method, distribution of structures found in different replicas has been analyzed and insights have been given as to how parallel tempering can be use effectively to handle this problem effectively.

Investigating the Characteristics and Evolution of Apical Membrane Antigen 1 (AMA1) of Plasmodium sp. using Phylogenetic Approach in Searching for Drug Candidate

Malaria is an endemic disease caused by Plasmodium parasite with female Anopheles mosquitoes as a vector. With the increase of drug resistance Plasmodium emerging around the world, a new method should be devised against the spread of Plasmodium sp lineage. Protein evolution of Plasmodium sp. can be an invaluable aid as an input for rational drug design and immune-informatics methods based on the novel virulent gene that exists in these protozoa. Previously, we did data mining in the PlasmoDB database and found several proteins shared by Plasmodium, one of them was the Apical Membrane Antigen 1 (AMA1). This protein was further analyzed for its characteristics and evolutionary properties. AMA1 protein sequences from human-infecting Plasmodium (P. falciparum, vivax, knowlesi, ovale, and malariae) and non-infectious (P. berghei, coatneyi, and cynomolgi) were retrieved from PlasmoDB. Maximum likelihood phylogenetic tree with molecular clock analysis was reconstructed from AMA1 sequences using MEGAX. Protein domain analysis was done using the INTERPRO server. Several domains that can induce protective immunity and vaccine target were found in AMA1 of those plasmodium, such as coiled-coil, disordered region, and signal peptide domain. Furthermore, molecular clock analysis showed a similar evolutionary rate between AMA1 protein in human-infecting and non-infectious Plasmodium. Interestingly, the phylogenetic tree showed a mixed cluster of human- infecting with non-infectious, indicating a unique evolutionary relationship between Plasmodium lineage. Thus, this information could be beneficial in developing the drug and vaccine for Plasmodium-related infection.&#x0D; Keywords: AMA1, drug target, protein domain, protein evolution, Plasmodium.

Supporting care for suboptimally controlled type 2 diabetes mellitus in general practice with a clinical decision support system: a mixed methods pilot cluster randomised trial

ObjectivesWe developed a complex intervention called DECIDE (ComputeriseD dECisIonal support for suboptimally controlleD typE 2 Diabetes mellitus in Irish General Practice) which used a clinical decision support system to address...

Hydrogen generation from water splitting by catalysts of platinum-based clusters Pt3X (X=Al, Si, Cu) and CO oxidation by their by-products

Reducing sizes of precious metals and utilization of the mixed small clusters of them as catalysts in reactions are important methods due to more active sites for higher catalytic efficiency. Based on first-principles calculations in this work, we found that the platinum-based clusters of Pt3X (X=Al, Si, Cu) which have the magic number 4 can effectively catalyze the water decomposition and hydrogen production in just one-step reaction process. The adsorbates of the H2O@Pt3X clusters have strong absorption in the ultraviolet and visible regions with wavelength from 300 nm to 760 nm, indicating the sunlight can be used to drive catalytic hydrolysis for producing clean hydrogen. In addition, the O atom remains on the clusters after hydrolysis and can react with CO to form CO2 in activation barrier of 0.34−0.58 eV, showing the recycling ability of the products after hydrolysis for eliminating the “poisoning” CO by oxidation. Moreover, the formed CO2 molecule can be detached from the Pt3X clusters at 323 K. Our results provide interesting guidance for practical designing the useful photocatalysts.

Computation-led design of pollutant gas sensors with bare and carbon nanotube supported rhodium alloys

Quantum chemical study has been performed on finite-sized bi-metallic Rh3M alloys, M = Ag, Ir, Pd, Pt, Au, derived from magic cluster, Rh4. Bond length of C–O and N–O are noticed to be elongated in the presence of rhodium alloy clusters. CO2 and NO2 gases are found to be highly adsorbed on Rh3M clusters, which is confirmed by stretching frequency of C–O and N–O. DFT evaluated dipole moment and electronic charge redistribution suggests the sensing capability of CO2 and NO2 gases by Rh3M clusters which is further confirmed by the calculated HOMO–LUMO gap. Mixed rhodium alloy clusters supported on single-wall carbon nanotube (SWCNT) exhibits much higher ability to sense CO2 and NO2. On the other hand, SWCNT@Rh3M shows higher catalytic activity for the activation of CO2 and NO2 in comparison to bare Rh3M because of the higher electronic charge redistribution in the case of SWCNT@Rh3M. In case of SWCNT-supported gas adsorbed clusters, p electrons play a major role in bonding.

Exploring How Professionals Within Agile Health Care Informatics Perceive Visualizations of Log File Analyses: Observational Study Followed by a Focus Group Interview.

BackgroundAn increasing number of software companies work according to the agile software development method, which is difficult to integrate with user-centered design (UCD) practices. Log file analysis may provide opportunities for integrating UCD practices in the agile process. However, research within health care information technology mostly has a theoretical approach and is often focused on the researcher’s interpretation of log file analyses.ObjectiveWe aimed to propose a systematic approach to log file analysis in this study and present this to developers to explore how they react and interpret this approach in the context of a real-world health care information system, in an attempt to answer the following question: How may log file analyses contribute to increasing the match between the health care system and its users, within the agile development method, according to agile team members?MethodsThis study comprised 2 phases to answer the research question. In the first phase, log files were collected from a health care information system and subsequently analyzed (summarizing sequential patterns, heat mapping, and clustering). In the second phase, the results of these analyses are presented to agile professionals during a focus group interview. The interpretations of the agile professionals are analyzed by open axial coding.ResultsLog file data of 17,924 user sessions and, in total, 176,678 activities were collected. We found that the Patient Timeline is mainly visited, with 23,707 (23,707/176,678; 13.42%) visits in total. The main unique user session occurred in 5.99% (1074/17,924) of all user sessions, and this comprised Insert Measurement Values for Patient and Patient Timeline, followed by the page Patient Settings and, finally, Patient Treatment Plan. In the heat map, we found that users often navigated to the pages Insert Measurement Values and Load Messages Collaborate. Finally, in the cluster analysis, we found 5 clusters, namely, the Information-seeking cluster, the Collaborative cluster, the Mixed cluster, the Administrative cluster, and the Patient-oriented cluster. We found that the interpretations of these results by agile professionals are related to stating hypotheses (n=34), comparing paths (n=31), benchmarking (n=22), and prioritizing (n=17).ConclusionsWe found that analyzing log files provides agile professionals valuable insights into users’ behavior. Therefore, we argue that log file analyses should be used within agile development to inform professionals about users’ behavior. In this way, further UCD research can be informed by these results, making the methods less labor intensive. Moreover, we argue that these translations to an approach for further UCD research will be carried out by UCD specialists, as they are able to infer which goals the user had when going through these paths when looking at the log data.

The structures, electronic properties, and chemical bonding of binary alloy boron–aluminum clusters series B4Aln0/−/+ (n = 1–5)

The geometry structures, electronic properties, and chemical bonding of neutral, anionic and cationic alloy B4Aln (n = 1–5) clusters series were systematically studied by using density functional theory at the B3LYP/6-311+G(d) level of theory for geometry optimization and using coupled cluster single point energy calculations at the CCSD(T)/6-311+G(2df)//B3LYP/6-311+G(d) level of theory. Comprehensive structure search and calculations demonstrate that the Al atoms tend to occupy the periphery sites of all alloy clusters, and the lowest–energy structures prefer low spin states (singlet or doublet). For small alloy cluster with total number of atoms ≤6, the clusters display the rare Anti-Van’t Hoff/Le Bel motifs planar tetracoordinate boron (ptB) and planar pentacoordinate boron (ppB), whereas, for total number of atoms ≥7, it shows 3D configuration. To evaluate the stabilities and electronic properties of the global minimum isomers of each stoichiometry at different charge states, the binding energy, fragmentation energy, second–order difference of the total energy, HOMO–LUMO gap, ionization potential, and electron affinity have been evaluated. We find that for anionic and cationic alloy B4Aln−/+ (n = 1–5) clusters, the odd–n systems are more stable than the even–n ones. AdNDP analyses of the chemical bonding of the global minimum structures indicate that the classical 2c–2e bonds and multicenter nc–2e (n = 3–9) delocalized bonds are responsible for the stability of boron–aluminum mixed alloy clusters.

Mixed cationic clusters of nitrogen and hydrogen.

The addition of small impurities, such as a single proton charge carrier, in noble gas clusters has recently been shown to have considerable effects on their geometries and stabilities. Here, we report on a mass spectrometric study of cationic clusters of N2 molecules and the effects that adding hydrogen, in the form of D2, has on the systems. Protonated nitrogen clusters formed by the breakup of D2 are shown to have similar behaviors as protonated rare gas clusters. For larger systems consisting of different mixtures of intact N2 and D2, different molecular species are found to be interchangeable sometimes with regard to magic numbers. This is especially true for the (N2)n(D2)mD+ systems with n + m = 17, which is particularly abundant for all measured combinations of n and m.

Highly fluorescent aryl-cyclopentadienyl ligands and their tetra-nuclear mixed metallic potassium-dysprosium clusters.

Two alkyl substituted triaryl-cyclopentadienyl ligands [4,4′-(4-phenylcyclopenta-1,3-diene-1,2-diyl)bis(methylbenzene) (1) and 4,4′,4′′-(cyclopenta-1,3-diene-1,2,4-triyl)tris(methylbenzene) (2)] have been synthesized via cross-aldol condensation followed by Zn-dust mediated cyclization and acid catalyzed dehydration reactions. The fluorescence properties of 1 and 2 have been studied in solution and solid state. The ligands exhibited aggregation-induced emission enhancement (AIEE) in THF/water solution. 1 and 2 have been found to be significantly more fluorescent in the solid state than in their respective solutions. This phenomenon can be attributed to the strong intermolecular CH⋯π interactions present in 1 and 2 which leads to the tight packing of molecules in their solid-state. Both 1, 2 and their corresponding anions have been studied by theoretical calculations. Ligands 1 and 2 have been shown to react with anhydrous DyCl3 in the presence of potassium metal at high temperature to afford two fluorescent chloride-bridged tetra-nuclear mixed potassium–dysprosium metallocenes [(Me2Cp)4Dy2IIICl4K2]·3.5(C7H8) (5) and [(Me3Cp)4Dy2IIICl4K2]·3(C7H8) (6), respectively in good yields.

Crystallographic and spectroscopic characterization of a mixed actinide-lanthanide carbide cluster stabilized inside an Ih(7)-C80 fullerene cage.

A mixed actinide-lanthanide cluster fullerene, Sc2UC@Ih(7)-C80, was isolated and fully characterized. For the first time, the single crystal X-ray crystallographic analysis confirms a novel actinide-lanthanide cluster Sc2UC stabilized inside an Ih(7)-C80 cage. Moreover, the U[double bond, length as m-dash]C double bond distance is 2.01 Å, the shortest U[double bond, length as m-dash]C bond confirmed by crystallography so far.

Mixed uranyl and neptunyl cation-cation interaction-driven clusters: structures, energetic stability, and nuclear quadrupole interactions.

We present a state-of-the-art quantum chemical study of mixed cation-cation interaction (CCI) driven complexes composed of uranyl and neptunyl units. Specifically, we consider the stability of the D-shaped and T-shaped structural rearrangements in CCIs, various oxidation states of the uranium and neptunium atom (v and vi), as well as a different number of unpaired electrons. Furthermore, we scrutinize the nuclear quadrupole interactions of the bare actinyl subunits and the most stable mixed CCI clusters. The electric field gradients (and nuclear quadrupole coupling constants) of neptunyls are reported for the first time. The characteristic features of the nuclear quadrupole interactions for the bare neptunyl ions are very similar to those predicted for uranyls. When the CCI clusters are formed, a considerable asymmetry is introduced compared to the bare actinyl cations. Most importantly, we are able to distinguish different types of CCIs with respect to their structural arrangement and their total charge by analyzing the electric field gradients at the uranium and neptunium nuclei.

Effects of mixing between short-chain and branched-chain alcohols in protonated clusters.

The previous analysis of the neat protonated branched-chain alcohol clusters revealed the impact of steric repulsion and dispersion of the bulky alkyl group on the hydrogen-bonded (H-bonded) structures and their temperature-dependence. To further understand the influence of the alkyl groups in H-bonded clusters, we studied the mixing of the two extremes of alcohols, methanol (MeOH) and tert-butyl alcohol (t-BuOH), with an excess proton. Infrared spectroscopy and a structural search of first principles calculations on the size-selected clusters H+(MeOH)m(t-BuOH)t (m + t = 4 and 5) were conducted. Temperature-dependence of the dominant H-bonded structures was explored by the Ar-tagging technique and quantum harmonic superposition approach. By introducing the dispersion-corrected density functional theory methods, it was shown that the effects of dispersion due to the bulky alkyl groups in the mixed clusters cannot be ignored for t≥ 2. The computational results qualitatively depicted the characteristics of the observed IR spectra, but overestimation of the temperature-dependence with dispersion correction was clearly seen due to the unbalanced correction between linear H-bonded structures and compact cyclic ones. These results demonstrate the importance of extensive investigation and benchmarks on different levels of theory, and that a properly sampled structure database is crucial to evaluate theoretical models.

Aerosol from Biomass Combustion in Northern Europe: Influence of Meteorological Conditions and Air Mass History

Alkali-containing submicron particles were measured continuously during three months, including late winter and spring seasons in Gothenburg, Sweden. The overall aims were to characterize the ambient concentrations of combustion-related aerosol particles and to address the importance of local emissions and long-range transport for atmospheric concentrations in the urban background environment. K and Na concentrations in the particulate matter PM1 size range were measured by an Alkali aerosol mass spectrometer (Alkali-AMS) and a cluster analysis was conducted. Local meteorological conditions and trace gas and PM concentrations were also obtained for a nearby location. In addition, back trajectory analyses and chemical transport model (CTM) simulations were included for the evaluation. The Alkali-AMS cluster analysis indicated three major clusters: (1) biomass burning origin, (2) mixture of other combustion sources, and (3) marine origin. Low temperatures and low wind speed conditions correlated with high concentrations of K-containing particles, mainly owing to local and regional emissions from residential biomass combustion; transport of air masses from continental Europe also contribute to Cluster 1. The CTM results indicate that open biomass burning in the eastern parts of Europe may have contributed substantially to high PM2.5 concentrations (and to Cluster 1) during an episode in late March. According to the CTM results, the mixed cluster (2) is likely to include particles emitted from different source types and no single geographical source region seems to dominate for this cluster. The back trajectory analysis and meteorological conditions indicated that the marine origin cluster was correlated with westerly winds and high wind speed; this cluster had high concentrations of Na-containing particles, as expected for sea salt particles.

Water/methanol solutions characterized by liquid μ-jet XPS and DFT—The methanol hydration case

The advent of liquid μ-jet setups as proposed by Faubel and Winter – in conjunction with X-ray Photoemission Spectroscopy (XPS) – has opened up a large variety of experimental possibilities in the field of atomic and molecular physics. In this study, we present first results from a synchrotron-based XPS core level and valence band electron spectroscopy study on water (10-4 M aqueous NaCl solution) as well as a water/methanol mixture using the newly commissioned ALBA liquid μ-jet setup. The experimental results are compared with simulations from density functional theory (DFT) regarding the electronic structure of single molecules, pure molecular clusters, and mixed clusters configurations as well as previous experimental studies. We give a detailed interpretation of the core level and valence band spectra for the vapour and liquid phases of both sample systems. The resulting overall picture gives insight into the water/methanol concentrations of the vapour and liquid phases as well as into the local electronic structure of the pertinent molecular clusters under consideration, with a special emphasis on methanol as the simplest amphiphilic molecule capable of creating hydrogen bonds.

Redefining chemotherapy-induced peripheral neuropathy through symptom cluster analysis and patient-reported outcome data over time

BackgroundChemotherapy-induced peripheral neuropathy (CIPN) is common among cancer patients treated with neurotoxic chemotherapy agents. Better knowledge on symptom clusters of CIPN may help improve symptom management in clinical practice. This study aimed to identify symptom clusters of CIPN and to map their trajectories before initiation of chemotherapy to 12-month follow-up.MethodsA secondary analysis of a longitudinal dataset was conducted using principal component approach. The European Organization for the Research and Treatment of Cancer Quality of Life Questionnaires Core 30 and CIPN 20 were used to measure symptom clusters of CIPN in patients with mixed cancer diagnosis across 10 time points over 12 months.ResultsSample size in each assessment point ranged from 118 to 343 participants. Four CIPN symptom clusters were identified, including a clear sensory neuropathy symptom cluster, a mixed motor-sensory neuropathy symptom cluster, a mixed sensorimotor neuropathy symptom cluster, and a less clear autonomic neuropathy symptom cluster. The core symptoms in each symptom cluster were mostly stable while the secondary symptoms changed over time.ConclusionsThe analysis suggests that CIPN is predominantly a sensory neuropathy with no evidence of a pure motor dysfunction but with mixed motor-related and autonomic changes accompanying sensory dysfunctions over time. Future symptom management strategies can be designed based on the morphology of CIPN.

Transcriptional Profiling Reveals Strong Impact of Major Molecular Disease Subgroups and Mixed Epistasis in Chronic Lymphocytic Leukemia

While recurrent mutations in CLL have been extensively catalogued, how driver mutations affect disease phenotypes remains incompletely understood. To address this, we performed RNA sequencing on 184 CLL patient samples and linked gene expression changes to molecular subgroups, gene mutations and copy number variants. Library preparation was performed according to the Illumina TruSeq RNA sample preparation v2 protocol. Samples were paired-end sequenced and two to three samples were multiplexed per lane on Illumina HiSeq 2000, Illumina HiSeq3000/4000 or Illumina HiSeqX machines. Raw RNA-seq reads were demultiplexed and quality control was performed using FastQC version 0.11.5. Internal trimming with STAR version 2.5.2a was used to remove adapters before mapping. Mapping was performed using STAR version 2.5.2a against the Ensembl human reference genome release 75 (Homo sapiens GRCh37.75). STAR was run in default mode with internal adapter trimming using the clip3pAdapterSeq option. Mapped reads were summarized into counts using htseq-count version 0.9.0 with default parameters and union mode. Thus, only fragments unambiguously overlapping with one gene were counted. The count data were then imported into R (version 3.4) for subsequent analysis. We identified robust and previously unknown gene expression signatures associated with recurrent copy number variants (including trisomy 12, del11q22.3, del17p13, del18p12 and gain8q24), gene mutations (TP53, BRAF and SF3B1) and the mutation status of the immunoglobulin heavy-chain variable region (IGHV). The most profound gene expression changes were associated with IGHV, methylation groups and trisomy 12. We found evidence for a significant influence of CNVs beyond the gene dosage effect. In line with these observations, unsupervised clustering showed that these major biological subgroups form distinct clusters and are discernible by unsupervised clustering (IGHV, methylation groups and trisomy 12). We found 3275 genes significantly differentially expressed between M-CLL and U-CLL after adjustment for multiple testing using the method of Benjamini and Hochberg for FDR = 1% . In total 9.5 % of variance within gene expression was associated with the IGHV status. These data suggest a much larger impact on transcriptional changes than previously detected (Ferreira et al. 2014), a finding much more in line with the key impact of IGHV on clinical course and biology of disease. We found distinct expression pattern of up- and downregulated genes for trisomy 12 samples. Even though many upregulated genes are located on chromosome 12, the majority of differentially expressed genes are indeed distributed among the other chromosomes and cannot be therefore not be ascribed to a simple gene dosage effect. To investigate the role of genetic interactions, we tested the collaborative effect on gene expression phenotypes. We investigated epistatic gene expression changes for IGHV status and trisomy 12. Epistasis was defined as a non-linear effect on gene expression between sample with both variants co-occuring and the single variants alone. In total 893 genes showed specific expression pattern in a combined genotype (padj&lt;0.1). These expression changes differed from the expected change by simple combination of the single variant's effects. We observed different ways of epistatic interaction and clustered genes by them. In total, we identified five cluster of genes representing different ways of mixed epistasis as inversion down, suppression, different degrees of buffering and inversion up. To further investigate this interaction we used enrichment tests for genes in the different mixed epistasis cluster. We found genes upregulated in trisomy12 U-CLL sample, but suppressed in M-CLL trisomy12 samples were enriched in Wnt beta catenin and Notch signaling. In summary, our study provides a comprehensive reference data set for gene expression in CLL. We show that IGHV mutation status, recurrent gene mutations and CNVs drive gene expression in a previously underappreciated fashion. This includes epistatic interaction between trisomy 12 and IGHV. Using a novel way to describe coordinated changes we can group genes into sets related to buffering, inversion and suppression. Disclosures Sellner: Takeda: Employment.

Jahn-Teller and Pseudo Jahn-Teller Effects: Influences on the Electronic Structures of Small Transition, Main Group and Mixed Metal Clusters

The present review article focuses on the impact of the Jahn-Teller effect (JTE) including hidden JTE and pseudo JTE on the ground and low-lying electronic structures of small transition, main group, and mixed metal clusters. The discussions are based on the results acquired from the quantum chemical analysis involving complete active space multiconfiguration self-consistent field (CASMCSCF or CASSCF) together with multireference singles and doubles configuration interaction (MRSDCI) theories. Related computational results from density functional (DFT) and coupled cluster (CC) theories, and the available experimental evidences on the JT-distorted structures are also included for comparative analysis. The role of the relativistic effects on several heavy metal clusters is discussed in detail, since these effects could lead to either enhancement or the quenching of the JTE. The final section of the review manifests the JT-distortion of several mixed metal clusters of icosahedral symmetry and they are explained through a much simpler shell structure (jellium) model.

Mixed-Metal-Cluster Strategy for Boosting Electrocatalytic Oxygen Evolution Reaction of Robust Metal-Organic Frameworks.

Rational construction of mixed metal-organic frameworks (MOFs) has been proved to be an effective way to heighten the electrocatalytic performance for MOFs, while the function of mixed metal clusters in MOFs to the electrocatalytic activity has not been known. For the first time, we present a mixed-metal-cluster strategy to boost electrocatalytic oxygen evolution reaction (OER) performance for MOFs. Heterometal clusters (Fe2M(μ3-O) (CH3COO)6(H2O)3, denoted as Fe2M (M: Co or Ni)), were chosen as the metal source to construct two bimetal PCN-250-Fe2M. Then, we further mixed Fe2Co and Fe2Ni clusters to construct mixed-metal-cluster PCN-Fe2Co-Fe2Ni by the in situ solvothermal reaction. Consequently, the OER activity of PCN-Fe2Co-Fe2Ni shows a dramatic enhancement compared with that of the parent bimetal MOFs. The PCN-Fe2Co-Fe2Ni displays a lower overpotential of 271 mV (η10), small Tafel slope (67.7 mV dec-1), and good linear sweep voltammetry cycle stability for the OER. Combination of DFT calculation and experiment results show that the improved electrocatalytic activity of PCN-Fe2Co-Fe2Ni is ascribed to the increased electron density of Co and Ni active centers and electrochemically active areas.

Hierarchical cluster analysis and multiple event relocation of seismic event clusters in Hungary between 2000 and 2016

The objective of our paper is to develop a workflow that allows us to calculate more accurate hypocenter locations in seismic event clusters of aftershock sequences or artificial events. Due to the increased sensitivity of the seismological instruments and density of the network, we are able to record small natural and artificial events. The discrimination of these events is necessary to investigate the recent tectonic movements in the Pannonian Basin. As a first step, we performed a hierarchical cluster analysis on the events in the Hungarian National Seismological Bulletin using the spatial distances between the events to obtain event clusters. We selected 5 different test clusters from the list of clusters where two clusters consist of quarry blasts, another two consist of earthquakes, and the last one is a mixture of earthquakes and anthropogenic events. In the second step, to prepare for the double-difference multiple event location analysis, we manually revised the arrival time picks in the Hungarian National Seismological Bulletin in order to increase the consistency and accuracy of the arrival times. We obtained improved single-event locations with the iLoc algorithm using the RSTT 3D global velocity model to provide initial locations for the double-difference relocation. We applied waveform cross-correlation at every station to obtain the differential times and correlation matrices. In order to discriminate the events in the mixed event cluster, we repeated the hierarchical cluster analysis, but this time, we used the correlation matrix as a distance metric. Examining the shape of the resulting dendrogram, it is clear that certain subclusters are well separated. In these subclusters, the coordinates of the events are close to the mines, where explosive quarrying takes place. With this technique, we are able to identify explosions that were listed as earthquakes in the catalogue.