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We present an efficient implementation of the closed shell multilevel coupled cluster method where coupled cluster singles and doubles (CCSD) is used for the inactive orbital space and CCSD with perturbative triples (CC3) is employed for the smaller active orbital space. Using Cholesky orbitals, the active space can be spatially localized and the computational cost is greatly reduced compared to full CC3 while retaining the accuracy of CC3 excitation energies. For the small organic molecules considered we achieve up to two orders of magnitude reduction in the computational requirements. [ABSTRACT FROM AUTHOR]

The two-neutron Halo of 19-Boronhas been investigated within this work. This investigation used the Microscopic Cluster Model (MCM). The main properties of Halo nuclei such as binding energy, radius, and deformation of the core have been calculated in this study. The 19B has been defined in the shape of core-n-n. The 17B is the core of the system. The feature of the three-body system depended on a structure and a deformation of the core. The core of 17B hasn't been considered as an inert core but has some degree of freedom. This degree has a high influence on the structure of a three-body system. So we used the Microscopic Cluster Model (MCM). The main aim of this study is to expand using cluster model in a new version which is Microscopic Cluster Model. [ABSTRACT FROM AUTHOR]

The main point of this study is to determine when and where proton emission and β+-decay happen. The study focused on three factors, the Coulomb effect, a core deformation, and the clustering configurations. In this work it was used the Microscopic Cluster Model to describe the system. The description of any system that will fragment by clustering forms has been considered in order to expand this methodology to all radioactive nuclei. The results confirmed this logical description and support its use for all radioactive isotopes. The 17Ne has been investigated within this work. [ABSTRACT FROM AUTHOR]

Though discovered more than a half century ago metallic glasses remain a scientific enigma. Unlike crystalline metals, characterized by short, medium, and long-range order, in metallic glasses short and medium-range order persist, though long-range order is absent. This fact has prompted research to develop structural descriptions of metallic glasses. Among these are cluster-based models that attribute amorphous structure to the existence of clusters that are incommensurate with crystalline periodicity. Not addressed, however, are the chemical factors stabilizing these clusters and promoting their interconnections.We have found that glass formers are characterized by a rich cluster chemistry that above the glass transformation temperature promotes exchange as well as static and vibronic sharing of atoms between clusters. The vibronic mechanism induces correlated motions between neighboring clusters and we hypothesize that the distance over which these motions are correlated mediates metallic glass stability and influences critical cooling rates. [ABSTRACT FROM AUTHOR]

Most research on the course experience questionnaire (CEQ) has been conducted through conventional exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) within the independent cluster model framework (ICM-CFA). However, very few studies have focused on examining its multidimensionality using more flexible psychometric frameworks such as exploratory structural equation modelling (ESEM). This study aims to conduct an integrated test of multidimensionality on the short, 23-item version of the CEQ (CEQ23) by using ESEM, to test its construct and criterion-related validity and contribute to the current debate on its validity. The participants comprised 620 undergraduate psychology students. CEQ23 scores were examined through ESEM to identify two sources of construct-multidimensionality. This entailed contrasting ICM-CFA and ESEM solutions and comparing three alternative models. Construct and criterion-related validity were then analysed using common and emerging techniques. The results (a) confirmed the presence of a superior construct: students' perceptions of teaching quality, which is multifaceted and hierarchically structured; (b) supported a generally acceptable construct and criterion-related validity; and (c) highlighted some methodological weaknesses of conventional statistical techniques, which may underly the debate on the validity of the CEQ23. [ABSTRACT FROM AUTHOR]

Spectroscopic characterization of clusters is crucial to understanding the structures and reaction mechanisms at the microscopic level, but it has been proven to be a grand challenge for neutral clusters because the absence of a charge makes it difficult for the size selection and detection. Infrared (IR) spectroscopy based on threshold photoionization using a tunable vacuum ultraviolet free electron laser (VUV-FEL) has recently been developed in the lab. The IR-VUV depletion and IR+VUV enhancement spectroscopic techniques open new avenues for size-selected IR spectroscopies of a large variety of neutral clusters without confinement (i.e., an ultraviolet chromophore, a messenger tag, or a host matrix). The spectroscopic principles have been demonstrated by investigations of some neutral water clusters and some metal carbonyls. Here, the spectroscopic principles and their applications for neutral clusters are reviewed. [ABSTRACT FROM AUTHOR]

In this paper it is demonstrated how the free, and easily downloadable, software package called SMath Studio can be used to set up a model of alpha-particle scattering. The basic physics of the motion of an alpha-particle in the nuclear coulomb field is used to produce a simple stepwise computer algorithm which, in conjunction with a novel set of units, is incorporated into a SMath worksheet with graphical output. It is also shown how the computed results can be compared with traditional theory. [ABSTRACT FROM AUTHOR]

A 1D cluster model with next-nearest-neighbor interactions and two additional composite interactions is solved; the free energy is obtained and a correlation function is derived exactly. The model is diagonalized by a transformation obtained automatically from its interactions, which is an algebraic generalization of the Jordan–Wigner transformation. The gapless condition is expressed as a condition on the roots of a cubic equation, and the phase diagram is obtained exactly. We find that the distribution of roots for this algebraic equation determines the existence of long-range order, and we again obtain the ground-state phase diagram. We also derive the central charges of the corresponding conformal field theory. Finally, we note that our results are universally valid for an infinite number of solvable spin chains whose interactions obey the same algebraic relations. [ABSTRACT FROM AUTHOR]

Cluster structures in nuclei have been studied for half a century and one central problem is how to understand and describe the relative motion of clusters. In 2001, the THSR (Tohsaki-Horiuchi-Schuck-Röpke) wave function was proposed for exploring the possible $ \alpha $ condensation in $ n\alpha $ nuclei. This novel microscopic cluster wave function provides us with a new perspective for understanding general cluster correlations in nuclei. In this article, we will review a new understanding for cluster structures, that is the concept of nonlocalized clustering, which is inspired by the THSR wave function. The concept of nonlocalized clustering is characterized as the dimensional size parameter rather than the traditional inter-cluster distance parameter. Based on this concept, a container picture is introduced for describing and understanding the complicated motion of clusters in nuclei.

The Binary Cluster Model (BCM) has been employed with the single particle harmonic oscillator and Gaussian wave functions to study the ground state density distributions and the elastic form factors of proton rich 8B and 17Ne halo nuclei. The Glauber model with an optical limit approximation has been used to study the reaction cross sections for these nuclei in the low and high energy regions. The calculated results of reaction cross sections of these nuclei at both low and high energy give good agreement with experimental data. [ABSTRACT FROM AUTHOR]

Copyright of Dilemas Contemporáneos: Educación, Política y Valores is the property of Dilemas Contemporaneos: Educacion, Politica y Valores and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A reinterpretation of the complete energy spectrum of the Oxygen-16 nucleus up to 20 MeV, and partly beyond, is proposed. The underlying intrinsic shape of the nucleus is tetrahedral, as in the naive alpha-particle model and other cluster models, and A-, E- and F-vibrational phonons are included. The A- and F-phonons are treated in the harmonic approximation, but the E-vibrations are extended into a two-dimensional E-manifold of D 2 -symmetric, four-alpha-particle configurations, following earlier works. This allows for the underlying tetrahedral configuration to tunnel through a square configuration into the dual tetrahedron, with the associated breaking of parity doubling. The frequency of an E-phonon is lower than in other models, and the first-excited 0 + state at 6.05 MeV is modeled as a state with two E-phonons; this allows a good fit of the lowest 2 + and 2 − states as excitations with one E-phonon. Rotational excitations of the vibrational states are analyzed as in the classic works of Dennison, Robson and others, with centrifugal corrections to the rotational energy included. States with F-phonons require Coriolis corrections, and the Coriolis parameter ζ is chosen positive to ensure the right splitting of the 3 + and 3 − states near 11 MeV. Altogether, about 80 states with isospin zero are predicted below 20 MeV, and these match rather well the more than 60 experimentally tabulated states. Several high-spin states are predicted, up to spin 9 and energy 30 MeV, and these match some of the observed high-spin, natural-parity states in this energy range. The model proposed here is mainly phenomenological but it receives some input from analysis of skyrmions with baryon number 16. [ABSTRACT FROM AUTHOR]

Abstract Here we report the first spectroscopic alpha particle detection based on CsPbBr 3 detectors with asymmetric contacts. The CsPbBr 3 single crystal was grown from the melt using Bridgman method and then fabricated into detectors with different contacts. The In/CsPbBr 3 /Au detector presented a low dark current density (∼ 100 nA/cm2) and temporal stable performance under high electric field (1000 V/cm). Such detector demonstrated excellent gamma ray resolving capability with a full-width at half maximum (FWHM) of ∼ 5.9 keV for the 57Co 122 keV γ ray. The CsPbBr 3 detector was capable of simultaneously resolving both the alpha particle (5.5 MeV) and γ ray (59.5 keV) peaks from 241Am radioactive isotope. The transport properties of CsPbBr 3 were then determined based on the alpha particle spectra and corresponding rise time distributions. The equivalent values of electron and hole mobilities were indicated as 63 and 49 cm2/(V ⋅ s) respectively. The calculated electron and hole mobility-lifetime products were 4.5 × 10−4 and 9.5 × 10−4 cm2/V, respectively, demonstrating superior transport properties of holes over electrons in CsPbBr 3. This work widens the scope of perovskite detectors to encompass charged radiation as well as high energy X/ γ rays, and will significantly promote and guide further studies on perovskite materials for radiation detection applications. Highlights • The first α particle spectroscopy by CsPbBr 3 detectors was clearly demonstrated. • In/CsPbBr 3 /Au detector was fabricated and exhibited low and stable dark current. • In/CsPbBr 3 /Au detector resolved both α particle and γ ray peaks from 241Am isotope. • The nearly balanced e and h mobilities of CsPbBr 3 were 63 and 49 cm2/(V s), respectively. • The μ τ products for e and h were 4.5 × 10−4 and 9.5 × 10−4 cm2/V, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Papers of Electrical & Control Engineering Faculty Technical University of Gdansk / Zeszyty Naukowe Wydzialu Elektrotechniki & Automatyki Politechniki Gdanskiej is the property of Gdansk University of Technology, Faculty of Electrical & Control Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The emission probabilities of γ rays produced in the 227Ac decay series were determined by high-resolution γ-ray spectrometry of sources with standardised activity. The sources were prepared quantitatively on glass discs by drop deposition of a solution with 227Ac in radioactive equilibrium with its daughter nuclides. Their activity was measured by a primary standardisation technique based on alpha-particle counting at a defined low solid angle. Four laboratories performed γ-ray spectrometry and derived absolute γ-ray intensities. Mean values were calculated and compared with literature data and the currently recommended evaluated data. New values on certain γ-ray emission probabilities are proposed. Highlights • Measured gamma-ray emission probabilities in 227Ac decay series. • Mean values taken from 4 laboratories. • Source activity determined by primary standardisation. • Results reported for 87 γ-ray lines. • Generally in good agreement with literature values. [ABSTRACT FROM AUTHOR]

This study was carried out to examine the potential of antimony tri-iodide (SbI3) as a material for radiation detectors that operate at room temperature. SbI3 is a compound semiconductor with an AsI3-type crystal structure, high atomic number (Sb: 51, I: 53), high density (4.92 g/cm3), and a wide band-gap energy (2.2 eV). In addition, crystalline SbI3 is easy to grow by conventional crystal growth techniques from melting phase because the material exhibits a low melting point (171°C) and undergoes no phase transition in the range of its solid phase. In this study, SbI3 crystals were grown by the Bridgman method after synthesis of SbI3 from 99.9999% pure Sb and 99.999% pure I2. The grown crystals consisted of several large grains with red color and were confirmed to be single-phase crystals by X-ray diffraction analysis. SbI3 detectors with a simple planar structure were fabricated using the cleavage plates of the grown crystals, and the pulse-height spectra were recorded at room temperature using an 241Am alpha-particle (5.48 MeV) source. The detector showed response to the alpha-particle radiation. [ABSTRACT FROM AUTHOR]

A presence-absence map consists of indicators of the occurrence or nonoccurrence of a given species in each cell over a grid, without counting the number of individuals in a cell once it is known it is occupied. They are commonly used to estimate the distribution of a species, but our interest is in using these data to estimate the abundance of the species. In practice, certain types of species (in particular flora types) may be spatially clustered. For example, some plant communities will naturally group together according to similar environmental characteristics within a given area. To estimate abundance, we develop an approach based on clustered negative binomial models with unknown cluster sizes. Our approach uses working clusters of cells to construct an estimator which we show is consistent. We also introduce a new concept called super-clustering used to estimate components of the standard errors and interval estimators. A simulation study is conducted to examine the performance of the estimators and they are applied to real data. [ABSTRACT FROM AUTHOR]

According to the experimental results, even–even light nuclei have cluster structures at some excited states. To study nuclei having two identical clusters we used a two-center potential well model. We calculated the energy levels by solving the Schrödinger equation and evaluating the effect of spin–orbit coupling in cylindrical coordinates. Finally, the results of calculations were applied for the 8Be isotope. [ABSTRACT FROM AUTHOR]

Purpose: The most exposed tissue upon radon exposure is the bronchial epithelium where goblet cells serve as responsive and adaptable front-line defenders. They can rapidly produce a vast amount of mucus, and can change in number, in response to airway insults. The objective of the present study is to quantify the effects of mucus discharge and goblet cell hyperplasia on the microscopic dose consequences of macroscopic radon exposures. Methods: For this purpose, computational models of the bronchial epithelium and alpha-particle transport have been prepared and applied to quantify the hits received and doses absorbed by cell nuclei in case of different mucus thicknesses and goblet cell number. Results and conclusions: Both mucus discharge and induction of goblet cell hyperplasia reduce radiation burden at the cellular level, and as such they both can be considered as radioadaptive responses to radon exposure. As compared to basal cell hyperplasia, goblet cell hyperplasia is more effective in reducing the microscopic dose consequences of a given macroscopic exposure. Such changes in exposure geometry highlight the need for improvements in the application of biokinetic and dosimetry models for incorporated radionuclides as well as the dose and dose rate effectiveness factor. [ABSTRACT FROM AUTHOR]

Alpha-particle counting at a defined solid angle (DSA) is one of the most accurate methods used in the primary activity standardization of alpha-particle emitting radionuclides. The important features of the technique are geometrically calculated efficiency and low background energy spectra. This paper describes measurement conditions of the DSA counter installed at Turkish Atomic Energy Authority - Sarayköy Nuclear Research and Training Center (TAEK-SANAEM) and source preparation apparatus. Details of source preparation, preliminary work of measurement and solid angle calculations are explained. The standardization of the activity of 241 Am sources with detailed uncertainty analysis is reported as part of a validation of the method. [ABSTRACT FROM AUTHOR]

A new approach is proposed in order to spatially localize and determine the equilibrium state of natural decay chains on hand-scale geological samples, thanks to a combination of three techniques: 1) Elementary chemical mapping by microprobe; 2) Alpha autoradiograph by gaseous detectors and 3) bulk alpha particle spectrometry. The quantitative nature of alpha autoradiograph and its comparison with U chemical maps allows to locate radioactive equilibrium state in four samples. This equilibrium state was confirmed by alpha spectrometry analysis. [ABSTRACT FROM AUTHOR]

In this study, a stepwise cluster modeling approach (SCMA) is developed for analyzing urban ecosystem variation via Normalized Difference Vegetation Index (NDVI). NDVI is an indicator of vegetation growth and coverage and useful in reflecting urban ecosystem. SCMA is established on a cluster tree that can characterize the complex relationship between independent and dependent variables. SCMA is applied to the City of Dongguan for simulating the urban NDVI and identifying associated drivers of human activity, topography and meteorology without specific functions. Results show that SCMA performances better than conventional statistical methods, illustrating the ability of SCMA in capturing the complex and nonlinear features of urban ecosystem. Results disclose that human activities play negative effects on NDVI due to the destruction of green space for pursuing more space for buildings. NDVI reduces gradually from the south part to the north part of Dongguan due to increased gross domestic product and population density, indicating that the ecosystem in Dongguan is better in the south part. NDVI in the northeast part (dominated by agriculture) is sensitive to the growth of economy and population. More attention should be paid to this part for sustainable development, such as increasing afforestation, planting grass and constructing parks. Precipitation has a positive effect on NDVI due to the promotion of soil moisture that is beneficial to plants’ growth. Awareness of these complexities is helpful for sustainable development of urban ecosystem. [ABSTRACT FROM AUTHOR]

In this paper, we mainly investigate the local theory of integral Banach mapping spaces. We introduce notions of integral injectivity, integral local reflexivity, integral exactness and integral nuclearity. We prove that any dual Banach space is integral injective and any Banach space is integral locally reflexive. To our surprise, we also obtain that C is the unique Banach space which is integral exact or integral nuclear. [ABSTRACT FROM AUTHOR]

The use of targeted radionuclide therapy for cancer is on the rise. While beta-particle-emitting radionuclides have been extensively explored for targeted radionuclide therapy, alpha-particle-emitting radionuclides are emerging as effective alternatives. In this context, fundamental understanding of the interactions and dosimetry of these emitted particles with cells in the tumor microenvironment is critical to ascertaining the potential of alpha-particle-emitting radionuclides. One important parameter that can be used to assess these metrics is the S-value. In this study, we characterized several alpha-particle-emitting radionuclides (and their associated radionuclide progeny) regarding S-values in the cellular and tumor-metastasis environments. The Particle and Heavy Ion Transport code System (PHITS) was used to obtain S-values via Monte Carlo simulation for cell and tumor metastasis resulting from interactions with the alpha-particle-emitting radionuclides, lead-212 (212Pb), actinium-225 (225Ac) and bismuth-213 (213Bi); these values were compared to the beta-particle-emitting radionuclides yttrium-90 (90Y) and lutetium-177 (177Lu) and an Auger-electron-emitting radionuclide indium-111 (111In). The effect of cellular internalization on S-value was explored at increasing degree of internalization for each radionuclide. This aspect of S-value determination was further explored in a cell line-specific fashion for six different cancer cell lines based on the cell dimensions obtained by confocal microscopy. S-values from PHITS were in good agreement with MIRDcell S-values (cellular S-values) and the values found by Hindié et al. (tumor S-values). In the cellular model, 212Pb and 213Bi decay series produced S-values that were 50- to 120-fold higher than 177Lu, while 225Ac decay series analysis suggested S-values that were 240- to 520-fold higher than 177Lu. S-values arising with 100% cellular internalization were two- to sixfold higher for the nucleus when compared to 0% internalization. The tumor dosimetry model defines the relative merit of radionuclides and suggests alpha particles may be effective for large tumors as well as small tumor metastases. These results from PHITS modeling substantiate emerging evidence that alpha-particle-emitting radionuclides may be an effective alternative to beta-particle-emitting radionuclides for targeted radionuclide therapy due to preferred dose-deposition profiles in the cellular and tumor metastasis context. These results further suggest that internalization of alpha-particle-emitting radionuclides via radiolabeled ligands may increase the relative biological effectiveness of radiotherapeutics. [ABSTRACT FROM AUTHOR]

For the detection of plutonium particles released from the Fukushima Daiichi nuclear power plant, we developed a high-resolution alpha-particle imaging system. The detector of the alpha-particle imaging system consists of a thin ZnS(Ag) sheet, a light guide, and a high quantum efficiency 1-inch square position-sensitive photomultiplier tube (PSPMT). The ZnS(Ag) sheet was optically coupled to the PSPMT with a 1.5 mm thick light guide between them. The Anger principle was used for the position calculation of the alpha particles. The spatial resolution of the alpha-particle imaging detector was 0.45 mm full width at half maximum for 5.5 MeV alpha particles. The uniformity of the imaging detector in the central part of the field of view was ±7%. The detection efficiency was 76% for 5.5 MeV alpha particles. Although the background count rate was 8.1 counts per minute because of the collection and detection of alpha particles from radon daughters in the air, it could be decreased to 0.1 counts per minute if the detector surface was covered with paper. There was no increase in the background count rates of 137 Cs gamma photons and 45 Ca beta particles. We obtained high-resolution variable phantom images and particles of alpha emitters with the system. We conclude that the alpha-particle imaging system developed is promising for the detection of plutonium particles in samples collected near the Fukushima Daiichi nuclear power plant. [ABSTRACT FROM AUTHOR]

The evaluation of evidence provided by geological studies and historical catalogs indicates that in some seismic regions and faults, multiple large earthquakes occur in cluster. Then, the occurrences of large earthquakes confront with quiescence and only the small-to-moderate earthquakes take place. Clustering of large earthquakes is the most distinguishable departure from the assumption of constant hazard of random occurrence of earthquakes in conventional seismic hazard analysis. In the present study, a time-dependent recurrence model is proposed to consider a series of large earthquakes that occurs in clusters. The model is flexible enough to better reflect the quasi-periodic behavior of large earthquakes with long-term clustering, which can be used in time-dependent probabilistic seismic hazard analysis with engineering purposes. In this model, the time-dependent hazard results are estimated by a hazard function which comprises three parts. A decreasing hazard of last large earthquake cluster and an increasing hazard of the next large earthquake cluster, along with a constant hazard of random occurrence of small-to-moderate earthquakes. In the final part of the paper, the time-dependent seismic hazard of the New Madrid Seismic Zone at different time intervals has been calculated for illustrative purpose. [ABSTRACT FROM AUTHOR]

We investigate the two-proton capture reaction of the prominent rapid proton capture waiting point nucleus, 68 Se, that produces the borromean nucleus 70 Kr ( Se 68 + p + p ). We apply a recently formulated general model where the core nucleus, 68 Se, is treated in the mean-field approximation and the three-body problem of the two valence protons and the core is solved exactly. We compare using two popular Skyrme interactions, SLy4 and SkM*. We calculate E 2 electromagnetic two-proton dissociation and capture cross sections, and derive the temperature dependent capture rates. We vary the unknown 2 + resonance energy without changing any of the structures computed self-consistently for both core and valence particles. We find rates increasing quickly with temperature below 2–4 GK after which we find rates varying by about a factor of two independent of 2 + resonance energy. The capture mechanism is sequential through the f 5 / 2 proton-core resonance, but the continuum background contributes significantly. [ABSTRACT FROM AUTHOR]

The selective oxidation of ethane over pure SBA-15 and V/SBA-15 were theoretically studied by density functional theory. The cluster models of pure SBA-15 and V/SBA-15 were proposed. The structure properties of these two models were calculated and were found to be in good agreement with experimental values. The catalytic reaction pathways for the ethane oxidation to acetaldehyde and ethylene were determined. Our results show that the hydroxyl groups on pure SBA-15 can activate the gas-phase O2 to form a peroxide species, which acts as the active site for the selective oxidation of ethane. The formation of ethylene is much more preferred than that of acetaldehyde over pure SBA-15. For V/SBA-15, the peroxide species also acts as the active center. The energy barrier of C-H bond activation over V/SBA-15 is by 14.63 kJ/mol lower than that over pure SBA-15. The formation of acetaldehyde is preferred than that of ethylene over V/SBA-15. On the basis of our results, the reaction mechanisms of ethane selective oxidation over pure SBA-15 and V/SBA-15 were systematically compared and discussed. The theoretical results in this study are in good agreement with our previous experimental results. They can reasonably explain the catalytic nature of pure SBA-15 and the effect of vanadium, opening new perspectives in the understanding of the chemistry of SBA-15. [ABSTRACT FROM AUTHOR]

Clusters of industry are widely accepted as important aspects of the regional economies wherein they are disposed, since within them, complementarities of the cluster members are witnessed to provide synergies and positive externalities. These forces deliver the cornerstone of collective sustainability, that is exhibited within healthy industrial clusters. One type of clusters that is deemed of distinct reputation, is the sort that is formulated around a core of maritime activity. Maritime clusters are discrete and volatile cases of the concept, since the maritime sector bears exemplary effect on any given economic cycle and simultaneously, markets riddled with shipping activities portray near-perfect competition. Maritime clusters have provided research and practice with a fertile ground to formulate and assess theories, though we are far from a unifying one. In addition, the literature is not without paradox. One paradoxical instance that affects all clusters, is that of the scarcity principle's applicability within the rudiments of a cluster, as it pertains to a domain that hasn’t been researched extensively. This work relinquishes a baseline model that deconstructs the scarcity paradox within maritime clusters, that will hopefully provide a feasible stepping stone for further theoretical and empirical research, with distinct implications for management, governance, and policy. [ABSTRACT FROM AUTHOR]

The binary cluster model (BCM) and the two-frequency shell model (TFSM) have been used to study the ground state matter densities of neutron-rich 6He and 11Li halo nuclei. Calculations show that both models provide a good description on the matter density distribution of above nuclei. The root-mean square (rms) proton, neutron and matter radii of these halo nuclei obtained by TFSM have been successfully obtained. The elastic charge form factors for these halo nuclei are studied through combining the charge density distribution obtained by TFSM with the plane wave Born approximation (PWBA). [ABSTRACT FROM AUTHOR]

A model describing the ionization of atoms and ions in a cluster under irradiation by a short laser pulse has been constructed. It is shown that the electron-impact ionization weakly affects the final charge composition, and the main mechanism of ion formation in the cluster is the over-barrier ionization by an electric field. The electric field acting on atoms and ions is the result of combined action of the external laser field and the intrinsic electric field of the cluster. The key parameters of the cluster beam and the laser pulse, which determine the properties of the charge composition of the cluster plasma, have been established. [ABSTRACT FROM AUTHOR]

There is a continued need for further clarification of various aspects of radiation-induced chromosomal aberration, including its correlation with radiation track structure. As part of the EMRP joint research project, Biologically Weighted Quantities in Radiotherapy (BioQuaRT), we performed experimental and theoretical analyses on chromosomal aberrations in Chinese hamster ovary cells (CHO-K1) exposed to α particles with final energies of 5.5 and 17.8 MeV (absorbed doses: ∼2.3 Gy and ∼1.9 Gy, respectively), which were generated by the microbeam at the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig, Germany. In line with the differences in linear energy transfer (approximately 85 keV/μm for 5.5 MeV and 36 keV/μm for 17.8 MeV α particles), the 5.5 MeV α particles were more effective than the 17.8 MeV α particles, both in terms of the percentage of aberrant cells (57% vs. 33%) and aberration frequency. The yield of total aberrations increased by a factor of ∼2, although the increase in dicentrics plus centric rings was less pronounced than in acentric fragments. The experimental data were compared with Monte Carlo simulations based on the BIophysical ANalysis of Cell death and chromosomal Aberrations model (BIANCA). This comparison allowed interpretation of the results in terms of critical DNA damage [cluster lesions (CLs)]. More specifically, the higher aberration yields observed for the 5.5 MeV α particles were explained by taking into account that, although the nucleus was traversed by fewer particles (nominally, 11 vs. 25), each particle was much more effective (by a factor of ∼3) at inducing CLs. This led to an increased yield of CLs per cell (by a factor of ∼1.4), consistent with the increased yield of total aberrations observed in the experiments. [ABSTRACT FROM AUTHOR]

A new Pb(II) coordination polymer, namely [Pb 2 (bptc)(DMA)] n ( 1 , H 4 bptc = biphenyl-3,3′,5,5′-tetracarboxylic acid, DMA = N, N′- dimethylacetamide), has been synthesized by the combination of H 4 bptc with Pb(NO 3 ) 2 under solvothermal conditions. Single crystal X-ray diffraction analysis revealed that compound 1 features a 3D framework based on tetranuclear [Pb 4 (COO) 6 ] subunits, and topological analysis revealed that compound represents a binodal (4, 8)-connected scu-type topological network with the point symbol of {4 16 ,6 12 }{4 4 ,6 2 } 2 . Luminescence studies indicated that 1 and 1’ ( 1′ represents the desolvated samples) showed intense yellow emissions. Significantly, 1′ exhibited sensitive luminescence sensing for CS 2 solvent molecules at a low concentration. [ABSTRACT FROM AUTHOR]

Inertial confinement fusion cryogenic-layered implosions at the National Ignition Facility, while successfully demonstrating self-heating due to alpha-particle deposition, have fallen short of the performance predicted by one-dimensional (1D) multi-physics implosion simulations. The current understanding, from experimental evidence as well as simulations, suggests that engineering features such as the capsule tent and fill tube, as well as time-dependent low-mode asymmetry, are to blame for the lack of agreement. A short series of experiments designed specifically to avoid these degradations to the implosion are described here in order to understand if, once they are removed, a high-convergence cryogenic-layered deuterium-tritium implosion can achieve the 1D simulated performance. The result is a cryogenic layered implosion, round at stagnation, that matches closely the performance predicted by 1D simulations. This agreement can then be exploited to examine the sensitivity of approximations in the model to the constraints imposed by the data. [ABSTRACT FROM AUTHOR]

In the modified potential cluster model, the possibility of describing the astrophysical S-factor of radiative p7Ве→8Bγ capture to the ground state of the 8B nucleus at energies from 10 keV to 1 MeV is considered. Potentials of intercluster interactions, matched to the spectra of the 8B nucleus for scattering processes, and the potential of the bound 3Р2 ground state in the p7Ве cluster channel are constructed. The resonance in the 3P1 scattering wave at the energy 0.722 MeV, which leads to an М1-transition to the ground state, is considered. Total cross sections and the reaction rate of p7Ве capture are calculated in the temperature range from 0.01·Т9 to 5·Т9. [ABSTRACT FROM AUTHOR]

Within the cluster-core model picture using the preformed cluster model, proton rich, 2-proton emitting nuclei are studied. The experimentally established Fe, Ni, Zn and Kr are investigated in terms of simple potential energy surfaces for all possible cluster plus core configurations of the 2-proton emitting nuclei. The calculated potential energy surfaces reveal a strong minimum for 2-proton-cluster plus core configuration. In addition, the calculations are carried out for the theoretically studied 2-proton emitters such as , , , , , and , which also reveal 2-proton cluster plus core configuration as the favorable one possessing strong minimum in the potential energy surface. Furthermore, the calculated potential energies are used to calculate the preformation probability by solving the stationary Schrödinger equation of motion in mass asymmetry coordinate. The formation yield also clearly reveals a larger formation probability for the 2-proton cluster plus core configuration for all the nuclei studied. The Q-value systematic of 1-proton, 2-proton, 4-proton and 4He is also analyzed. [ABSTRACT FROM AUTHOR]

The structural and optical properties of α-quartz cluster with oxygen-deficiency centers (ODCs) defects have been investigated based on the density functional theory (DFT). For cluster models with ODC(I) defect, with the increasing of cluster size and shape, the equilibrium length of Si-Si bond decreases. The excitation peaks of cluster models with ODC(I) defect are from 6.87 eV to 7.39 eV, while the excitation peaks of cluster models with ODC(II) defect are from 5.20 eV to 5.47 eV. We also study the interconversion between ODCs (≡Si-Si≡ bond and divalent Si) induced by UV irradiation. Our study predicted the existence of a metastable structure of ODC(I) for the first time in literature. Our results are in good agreement with the previous results and provide strong theoretical support to the viability of the processes. [ABSTRACT FROM AUTHOR]

The necessity of measuring the radioactivity of the 230 Тh nuclide arises when attempting to solve a number of geochemical or geochronological problems based on the effects of radioactive disequilibrium in the 238 U series. It is the authors’ opinion that the use of the traditional α- and β-emitters of thorium as a radiotracer in order to determine the activity of 230 Тh leads to various inconveniences and difficulties of a technical nature. The authors recommend using the 234 Тh isotope contained in the study sample as the simplest and most natural way of measuring the chemical yield of the targeted nuclide ( 230 Тh). A sequence of radio-analytical procedures is proposed that will provide a correct assessment of the radioactivity of 230 Тh. In addition, a specific example and an evaluation of the accuracy of the proposed methodology are presented, using actual experimental data. [ABSTRACT FROM AUTHOR]

Analytical dependences of the effective heat conductivity coefficient of an individual cluster and cluster nanofluid are obtained on the basis of classical equations of continuum mechanics with allowance for the interaction of temperature fields of spherical particles inside a cluster. The calculated dependences of the heat-conductivity coefficient of the cluster nanofluid agree with the corresponding experimental data. [ABSTRACT FROM AUTHOR]

Scattering of 8 He from 4 He has been performed through the coincident detection of the scattered particles using a silicon array within a helium-4 gas volume with a 8 He beam. This permitted the reconstruction of the interaction probability as a function of position within the gas and hence the excitation function to be calculated together with the angular distribution of the products. These measurements also enabled the reconstruction of the two-neutron transfer to 6 He +  6 He. The measurements provide the first characterisation of the scattering of the α + 4 n , 8 He, halo nucleus from 4 He and the 2 n -transfer to populate the symmetric final state. The results indicate the presence of a L = 4 component at excitation energies of 14–15 MeV, consistent with a broad ( ∼ 1 MeV ) J π = 4 + resonance. These measurements would agree with generalized two-centre cluster model (GTCM) calculations indicating a cluster, or molecular, structure predicted at this energy. [ABSTRACT FROM AUTHOR]

Within the framework of the modified potential cluster model with classification of orbital states according to the Young tableaux and revised potential parameters for the HeHe, HHe, and HHe cluster channels of the nuclei Be, Li, and Li, astrophysical S-factors of processes of radiative HeHe capture from 20 keV, HHе capture from 10 keV, and ННе capture from 5 keV are considered. On the basis of the obtained results, the rates of all of the considered reactions are calculated in the temperature range from 0.05 to 5 T and a comparison with the results of other authors is carried out. [ABSTRACT FROM AUTHOR]

Node clustering or simply clustering provides an effective way of organizing the network to achieve energy efficiency, efficient distribution of workload, maintain a connected hierarchy and accomplish data aggregation. On the other hand multi-hop communication significantly reduces the energy required for communication and multi-path communication helps in distributing the relay load and it also increases reliability of the network. The proposed methodology in this paper is a combination of these three features. In addition to that, we have used fuzzy logic in cluster head (CH) selection to blend different parameters to select the set of best possible CHs and to handle the uncertainties in parametric quantities. There are five main aspects of the proposed algorithm (a) on demand based clustering (b) fuzzy logic based CH selection (c) dynamic unequal cluster range for CHs' (d) a cost function based multi-hop relay selections (e) Fibonacci sequence based relay load distribution. The proposed approach creates more balanced cluster by means of fuzzy logic and inequality in cluster range. It saves energy by conducting CH selection on demand basis. Finally, the cost function based multi-hop relay selections along with Fibonacci sequence based relay load distribution create an optimal structure for relaying data.The proposed approach is implemented and compared with the well known approaches like LEACH, ECPF, CHEF and UCR. Simulation results have shown that the proposed approach performs better, in every aspect of network life time and other metrics. [ABSTRACT FROM AUTHOR]

We studied the ground state band properties of 212 Po, 218 Rn and 232 U using the binary cluster model. The nuclei are treated as a 208 Pb-core plus a cluster interacting via a local potential of Saxon–Woods type functional form whose parameters are derived from Michigan-3-Yukawa (M3Y) microscopic potential model. Further correction in the internal structure of the hybrid potential model is attributed to the nucleon distribution in the overlap region of the core-cluster system. Overall our calculated results are found to compare favourably well with available experimental data. [ABSTRACT FROM AUTHOR]

Using the density functional theory coupled with the nonorthogonal tight-binding model, we analyze the chemisorption of hydrogen atoms and hydroxyl groups on the unstrained and stretched graphene sheets. Drawback of finite cluster model of graphene for the chemisorption energy calculation in comparison with the QM/QM approach applied is discussed. It is shown that the chemisorption energy for the hydroxyl group is sufficiently lower than for hydrogen at stretching up to 7.5%. The simultaneous paired chemisorption of hydrogen and hydroxyl groups on the same hexagon has also been examined. Adsorption of two radicals in ortho and para positions is found to be more energetically favorable than those in meta position at any stretching considered. In addition the energy difference between adsorbent pairs in ortho and para positions decreases as the stretching rises. It could be concluded that the graphene stretching leads to the loss of preferred mutual arrangement of two radicals on its surface. [ABSTRACT FROM AUTHOR]