Search

We derive an automatic procedure for generating a set of highly localized, nonorthogonal orbitals for linear scaling quantum Monte Carlo (QMC) calculations. We demonstrate the advantage of these orbitals for calculating the total energy of both semiconducting and metallic systems by studying bulk silicon and the homogeneous electron gas. For silicon, the improved localization of these orbitals reduces the computational time by a factor of 5 and the memory by a factor of 6 compared to localized, orthogonal orbitals. For jellium at typical metallic densities, we demonstrate that the total energy is converged to 3 meV per electron for orbitals truncated within spheres with radii $7{r}_{s}$, opening the possibility of linear scaling QMC calculations for realistic metallic systems.

First-principles density functional and quantum Monte Carlo calculations of light-element doped fullerenes reveal significantly enhanced molecular ${\mathrm{H}}_{2}$ binding for substitutional B and Be. A nonclassical three-center binding mechanism between the dopant and ${\mathrm{H}}_{2}$ is identified, which is maximized when the empty ${p}_{z}$ orbital of the dopant is highly localized. The calculated binding energies of $0.2--0.6\text{ }\text{ }\mathrm{eV}/{\mathrm{H}}_{2}$ is suited for reversible hydrogen storage at near standard conditions. The calculated ${\mathrm{H}}_{2}$ sorption process is barrierless, which could also significantly simplify the kinetics for the storage.

We investigate the impact of water on the optical absorption of prototypical silicon clusters. Our clusters contain 5 silicon atoms, tetrahedrally coordinated and passivated with either hydrogen or oxygen. We approach this complex problem by assessing the contributions of three factors: chemical reactivity, thermal equilibration, and dielectric screening. We find that the silanone (Si=O) functional group is not chemically stable in the presence of water and exclude this as a source of significant red shift in absorption in aqueous environments. We perform first principles molecular dynamics simulations of the solvation of a chemically stable, oxygenated silicon cluster with explicit water molecules at 300 K. We find a systematic 0.7 eV red shift in the absorption gap of this cluster, which we attribute to thermally induced fluctuations in the molecular structure. Surprisingly, we find no observable screening impact of the solvent, in contrast with consistent blue shifts observed for similarly sized organic molecules in polar solvents. The predicted red shift is expected to be significantly smaller for larger Si quantum dots produced experimentally, guaranteeing that their vacuum optical properties are preserved even in aqueous environments.

(2004). The general practitioner interface with people with intellectual disabilities and their supports. European Journal of General Practice: Vol. 10, No. 2, pp. 66-70.

A new methodology for frequency bandwidth enhancement using 3D layered reflectivity inversion is demonstrated in this paper. The inversion is used to obtain layered reflectivity and then band-limited to the outer bounds of the input seismic. The 3D reflectivity inversion starts with a thin layer model based on the geological picks following the structural and stratigraphic trends. The initial thickness of the thin layers is determined by the frequency bandwidth of the seismic data, and the inversion process orients them conformably to stratigraphic layers in the subsurface. The thickness and impedance of each layer (and hence interface reflection coefficient) is perturbed and the corresponding modelled synthetic is compared to the seismic data in a volumetric fashion to minimise the misfit (Walia, 2001). This contributes to the removal of tuning effects and provides a reflectivity sequence with a much higher frequency bandwidth than the seismic data. Subsequently, the reflection series is band-limited to obtain higher resolution seismic data. The limits of bandwidth enhancement is selected by correlating the enhanced seismic to well logs and VSPs. The comparison of seismic profiles attribute maps and correlation with well data presented in this paper confirm that this process has resolved real seismic events. This resulted in confident picking of top and base of individual sand units, consequently providing better maps of the reservoir sands. Application to Seismic Data Rigorous study of this technique on several 3D data volumes from the North Sea and Ecuador’s Oriente Basin have produced very encouraging results in terms of resolving Top/Base of producing thin sands, improving structural features and complex-fault definition. Fig. 1 shows a simple workflow of the methodology. An initial model, based on the main geological horizons and log data, is input to the inversion process. The inversion process describes the existing zero-phase 3D volume by a discrete number of thin (half of time-thickness of the input wavelet) layers (Ricker, 1953). Each layer consists of two parameters, the time thickness and initial impedance and hence reflection coefficient value at the interface of every bin location. During the inversion process both the parameters are perturbed within pre-defined constraints based on well log data. Convergence to the final solution is achieved using a full 3D algorithm based on simulated annealing. The resulting layered structure provides an effective resolution of typically an eighth of the wavelength (Gluck et al, 1997; Widess, 1973). The data reduction implicit in the layer definition makes this algorithm extremely robust to noise. This inverted reflectivity is then band-limited such that the enhanced seismic has a broader frequency bandwidth than the input seismic. Fig. 2 shows a comparison of the seismic data from the Oriente Basin before Hz dB

Ab initio calculations of the structural, electronic, and optical properties of CdSe nanoparticles are presented. The atomic structures of the clusters are relaxed both in vacuum and in the presence of surfactant ligands. In both cases, we predict significant geometrical rearrangements of the nanoparticle surface while the wurtzite core is maintained. These reconstructions lead to the opening of an optical gap without the aid of passivating ligands, thus ``self-healing'' the surface electronic structure. Our calculations also predict the existence of a midgap state responsible for recently observed subband emission.

We present calculations of the optical absorption spectra of clusters ${\mathrm{SiH}}_{4},$ ${\mathrm{Si}}_{10}{\mathrm{H}}_{16},$ ${\mathrm{Si}}_{17}{\mathrm{H}}_{36},$ ${\mathrm{Si}}_{29}{\mathrm{H}}_{24},$ and ${\mathrm{Si}}_{35}{\mathrm{H}}_{36},$ as determined from two different methods: the Bethe-Salpeter equation (BSE) with a model dielectric function, and the time-dependent density-functional theory within the adiabatic local-density approximation (TDLDA). Single-particle states are obtained from local-density approximation (LDA) calculations and, for the BSE calculation, a quasiparticle gap correction is provided by quantum Monte Carlo calculations. We find that the exchange-correlation kernel of the TDLDA has almost no effect on the calculated spectra, while the corresponding attractive part of the electron-hole interaction of the BSE produces enhanced absorptive features at low energies. For the smallest cluster ${\mathrm{SiH}}_{4},$ the two methods produce markedly different results, with the TDLDA spectra appearing closer to the experimental result. The gross features of the TDLDA and BSE spectra for larger clusters are however similar, due to the strong repulsive Coulomb kernel present in both treatments.

We present density functional and quantum Monte Carlo calculations of the stability and optical properties of semiconductor nanomaterials with reconstructed surfaces. We predict the relative stability of silicon nanostructures with reconstructed and unreconstructed surfaces, and we show that surface step geometries unique to highly curved surfaces dramatically reduce the optical gaps and decrease excitonic lifetimes. These predictions provide an explanation of both the variations in the photoluminescence spectra of colloidally synthesized nanoparticles and observed deep gap levels in porous silicon.

First-principles molecular dynamics and quantum Monte Carlo techniques are employed to gain insight into the effect of preparation conditions on the structural and optical properties of silicon nanoparticles. Our results demonstrate that (i) kinetically limited nanostructures form different core structures than bulk-derived crystalline clusters, (ii) the type of core structure that forms depends on how the cluster is passivated during synthesis, and (iii) good agreement with measured optical gaps can be obtained for nanoparticles with core structures different from those derived from the bulk.

Quantum Monte Carlo (QMC) calculations of the optical gaps of silicon quantum dots ranging in size from 0 to 1.5 nm are presented. These QMC results are used to examine the accuracy of density functional (DFT) and empirical pseudopotential based calculations. The $GW$ approximation combined with a solution of the Bethe-Salpeter equation performs well but is limited by its scaling with system size. Optical gaps predicted by DFT vary by 1--2 eV depending on choice of functional. Corrections introduced by the time dependent formalism are found to be minimal in these systems.

A method is presented for using truncated, maximally localized Wannier functions to introduce sparsity into the Slater determinant part of the trial wave function in quantum Monte Carlo calculations. When combined with an efficient numerical evaluation of these localized orbitals, the dominant cost in the calculation, namely, the evaluation of the Slater determinant, scales linearly with system size. This technique is applied to accurate total energy calculation of hydrogenated silicon clusters and carbon fullerenes containing 20-1000 valence electrons.

We employ density functional and quantum Monte Carlo calculations to show that significant changes occur in the gap of fully hydrogenated nanoclusters when the surface contains passivants other than hydrogen, in particular atomic oxygen. In the case of oxygen, the gap reduction computed as a function of the nanocluster size provides a consistent interpretation of several recent experiments. Furthermore, we predict that other double bonded groups also significantly affect the optical gap, while single bonded groups have a minimal influence.

Provided that the shape, size, and composition profile of semiconductor-embedded quantum dots are given, theory is able to accurately calculate the excitonic transitions, including the effects of inhomogeneous strain, alloy fluctuations, electron-hole binding, and multiband and intervalley coupling. While experiment can accurately provide the spectroscopic signature of the excitonic transitions, accurate determination of the size, shape, and composition profile of such dots is still difficult. We show how one can arrive at a consistent picture of both the material and the electronic structure by interactive iteration between theory and experiment. Using high-resolution transmission electron microscopy, electron-energy-loss spectroscopy, and photoluminescence (PL) spectroscopy in conjunction with atomistic empirical pseudopotential calculations, we establish a model consistent with both the observed material structure and measured electronic/optical properties of a quantum dot sample. The structural model with best agreement between measured and predicted PL is a truncated cone with height 35 {angstrom}, base diameter 200 {angstrom}, and top diameter 160 {angstrom}, having a nonuniform, peaked composition profile with average 60% In content. Next, we use our best structure to study the effect of varying (i) the amount of In in the dots, and (ii) the spatial distribution of In within the dots. We find thatmore » by either increasing the amount of In within the dot or by concentrating a given amount of In near the center of the dot, both electrons and holes become more strongly bound to the dot. A small change of In content from 50 to 60% causes an exciton redshift of about 70 meV. Changing the composition profile from a uniform In distribution to a centrally peaked distribution can redshift the exciton by an additional 20--40 meV.« less

We report on the observation of photoluminescence from positive, neutral and negative charge states of single semiconductor quantum dots. For this purpose we designed a structure enabling optical injection of a controlled unequal number of negative electrons and positive holes into an isolated InGaAs quantum dot embedded in a GaAs matrix. Thereby, we optically produced the charge states -3, -2, -1, 0, +1 and +2. The injected carriers form confined collective 'artificial atoms and molecules' states in the quantum dot. We resolve spectrally and temporally the photoluminescence from an optically excited quantum dot and use it to identify collective states, which contain charge of one type, coupled to few charges of the other type. These states can be viewed as the artificial analog of charged atoms such as H$^{-}$, H$^{-2}$, H$^{-3}$, and charged molecules such as H$_{2}^{+}$ and H$_{3}^{+2}$. Unlike higher dimensionality systems, where negative or positive charging always results in reduction of the emission energy due to electron-hole pair recombination, in our dots, negative charging reduces the emission energy, relative to the charge-neutral case, while positive charging increases it. Pseudopotential model calculations reveal that the enhanced spatial localization of the hole-wavefunction, relative to that of the electron in these dots, is the reason for this effect., 5 figures

We adopt an atomistic pseudopotential description of the electronic structure of self-assembled, lens shaped InAs quantum dots within the ``linear combination of bulk bands'' method. We present a detailed comparison with experiment, including quantites such as the single particle electron and hole energy level spacings, the excitonic band gap, the electron-electron, hole-hole and electron hole Coulomb energies and the optical polarization anisotropy. We find a generally good agreement, which is improved even further for a dot composition where some Ga has diffused into the dots., 16 pages, 5 figures. Submitted to Physical Review B

We use a many-body, atomistic empirical pseudopotential approach to predict the multi-exciton emission spectrum of a lens shaped InAs/GaAs self-assembled quantum dot. We discuss the effects of (i) The direct Coulomb energies, including the differences of electron and hole wavefunctions, (ii) the exchange Coulomb energies and (iii) correlation energies given by a configuration interaction calculation. Emission from the groundstate of the $N$ exciton system to the $N-1$ exciton system involving $e_0\to h_0$ and $e_1\to h_1$ recombinations are discussed. A comparison with a simpler single-band, effective mass approach is presented.

Study objectives: To investigate whether a 12-week pulmonary rehabilitation program that includes moderately intensive exercise training performed twice weekly can induce a training effect in patients with a wide variation of airflow limitation. Participants: Sixty patients with COPD (38 men) with a mean 6 SD FEV1 % predicted of 55.1 6 19.8 (range, 0.51 to 2.99). All patients performed identical incremental symptom-limited cycle ergometer testing before and after a 12-week study period. Measurements and results: After 12 weeks, the patients demonstrated a significant (p < 0.05) increase in the peak values for work rate (WR; 77 6 30 vs 91 6 36 W) and oxygen uptake (1.14 6 0.45 vs 1.20 6 0.52 L/min). Furthermore, at a given WR during incremental symptomlimited cycle ergometer testing, there were significant (p < 0.05) reductions in minute ventilation (42.4 6 16.1 vs 37.0 6 13.6 L/min), carbon dioxide output (1.13 6 0.49 vs 1.03 6 0.42 L/min), ventilatory equivalent for oxygen (37.6 6 8.1 vs 36.0 6 6.3), and heart rate (135 6 15 vs 128 6 16 beats/min). None of the observed physiologic changes correlated with FEV1 % predicted. Conclusions: A pulmonary rehabilitation program performed twice weekly with moderate exercise workloads can lead to a physiologic training response irrespective of the degree of airflow limitation. (CHEST 1999; 116:1200 ‐1207)

Using atomistic pseudopotential wave functions we calculate the electron and hole charging energies of InAs quantum dots. We find that the charging energies depend strongly on the dielectric constant epsilon_out of the surrounding material, and that when the latter is smaller than the dielectric constant of the dot the electron-electron and hole-hole interactions are dominated by surface-polarization effects. We predict the addition energies and the quasi-particle gap as a function of size and epsilon_out. We find excellent agreement with recent single-dot tunneling spectroscopy data for epsilon_out=6., 11 pages, 3 figures

Excitonic spectra are calculated for free-standing, surface passivated InAs quantum dots using atomic pseudopotentials for the single-particle states and screened Coulomb interactions for the two-body terms. We present an analysis of the single particle states involved in each excitation in terms of their angular momenta and Bloch-wave parentage. We find that (i) in agreement with other pseudopotential studies of CdSe and InP quantum dots, but in contrast to k.p calculations, dot states wavefunction exhibit strong odd-even angular momentum envelope function mixing (e.g. $s$ with $p$) and large valence-conduction coupling. (ii) While the pseudopotential approach produced very good agreement with experiment for free-standing, colloidal CdSe and InP dots, and for self-assembled (GaAs-embedded) InAs dots, here the predicted spectrum does {\em not} agree well with the measured (ensemble average over dot sizes) spectra. (1) Our calculated excitonic gap is larger than the PL measure one, and (2) while the spacing between the lowest excitons is reproduced, the spacings between higher excitons is not fit well. Discrepancy (1) could result from surface states emission. As for (2), agreement is improved when account is taken of the finite size distribution in the experimental data. (iii) We find that the single particle gap scales as $R^{-1.01}$ (not $R^{-2}$), that the screened (unscreened) electron-hole Coulomb interaction scales as $R^{-1.79}$ ($R^{-0.7}$), and that the eccitonic gap sclaes as $R^{-0.9}$. These scaling laws are different from those expected from simple models., Comment: 12 postscript figures

Free-standing InP quantum dots have previously been theoretically and experimentally shown to have a direct band gap across a large range of experimentally accessible sizes. We demonstrated that when these dots are embedded coherently within a GaP barrier material, the effects of quantum confinement in conjunction with coherent strain suggest there will be a critical diameter of dot ({approx}60 {Angstrom}), above which the dot is direct, type I, and below which it is indirect, type II. However, the strain in the system acts to produce another conduction state with an even lower energy, in which electrons are localized in small pockets at the interface between the InP dot and the GaP barrier. Since this conduction state is GaP X{sub 1c} derived and the highest occupied valence state is InP, {Gamma} derived, the fundamental transition is predicted to be indirect in both real and reciprocal space ({open_quotes}type II{close_quotes}) for all dot sizes. This effect is peculiar to the strained dot, and is absent in the freestanding dot. {copyright} {ital 1998} {ital The American Physical Society}

A great deal of information is held within the quality management systems (QMS) of many companies. This information is collected and stored primarily to aid the quality system in its task of monitoring the companies performance and in allowing third party auditors access to the information that they need to make judgements on the health of the QMS. In general auditors have little time to access more than just a small sample of this information and it is an aim of the project described in this paper to make the information that companies have much more easily accessible to auditors and management alike both in its raw form and in its summary form. The project shows how, by using intelligent systems that can access a company’s QMS the change process can be eased. At present the quality of the automated information processes that we can build is far below that of an experienced auditor. However because of the speed and costs of on-line computing, much more information can be used in forming a view of the workings of the QMS. It is expected that this tool will aid the auditor make much better informed judgements leading to many benefits to both the company and the auditor.

With the development of large, multiproduct companies in the nineteenth century, there has been an interest and a need to find new ways to organise and control companies now too big for an individual to understand and manage. Many new management structures and techniques have been tried, with varying degrees of success, but several have shown that they can offer improved performance and understanding; one of these is the obvious idea of measurement!

The band structure of silicon is calculated at the Gamma, X, and L wave vectors using diffusion quantum Monte Carlo methods. Excited states are formed by promoting an electron from the valence band into the conduction band. We obtain good agreement with experiment for states around the gap region and demonstrate that the method works equally well for direct and indirect excitations, and that one can calculate many excited states at each wave vector. This work establishes the fixed-node DMC approach as an accurate method for calculating the energies of low lying excitations in solids., Comment: 5 pages, 1 figure

The electronic structure of interfaces between lattice-mismatched semiconductor is sensitive to the strain. We compare two approaches for calculating such inhomogeneous strain -- continuum elasticity (CE, treated as a finite difference problem) and atomistic elasticity (AE). While for small strain the two methods must agree, for the large strains that exist between lattice-mismatched III-V semiconductors (e.g. 7% for InAs/GaAs outside the linearity regime of CE) there are discrepancies. We compare the strain profile obtained by both approaches (including the approximation of the correct C_2 symmetry by the C_4 symmetry in the CE method), when applied to C_2-symmetric InAs pyramidal dots capped by GaAs., To appear in J. Appl. Physics

We have investigated the static dielectric properties of silicon rods and slabs below 10nm, in the long wavelength limit, by using first-principles density functional theory calculations. Surface structure is found to be the most important factor affecting the changes of the dielectric response at the nanoscale, compared to that of bulk Si, with significant differences observed between slabs and finite rods of similar lateral dimensions.

BACKGROUND While there is considerable literature on adults with Down syndrome who have dementia, there is little published on the epidemiology of other types of mental ill-health in this population. METHOD Longitudinal cohort study of adults with Down syndrome who received detailed psychiatric assessment (n = 186 at the first time point; n = 134 at the second time point, 2 years later). RESULTS The prevalence of Down syndrome for the 16 years and over population was 5.9 per 10 000 general population. Point prevalence of mental ill-health of any type, excluding specific phobias, was 23.7% by clinical, 19.9% by Diagnostic Criteria for Psychiatric Disorders for use with Adults with Learning Disabilities/Mental Retardation (DC-LD), 11.3% by ICD-10 Classification of Mental and Behavioural Disorders: Diagnostic Criteria for Research (DCR-ICD-10) and 10.8% by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Revised (DSM-IV-TR) criteria. Two-year incidence of mental ill-health of any type was 14.9% by clinical and DC-LD, 9.0% by DCR-ICD-10 and 3.7% by DSM-IV-TR criteria. The highest incidence was for depressive episode (5.2%) and dementia/delirium (5.2%). Compared with persons with intellectual disabilities (ID) of all causes, the standardized rate for prevalence of mental ill-health was 0.6 (0.4-0.8), or 0.4 (0.3-0.6) if organic disorders are excluded, and the standardized incidence ratio for mental ill-health was 0.9 (0.6-1.4), or 0.7 (0.4-1.2) if organic disorders are excluded. Urinary incontinence was independently associated with mental ill-health, whereas other personal factors, lifestyle and supports, and other types of health needs and disabilities were not. CONCLUSIONS Mental ill-health is less prevalent in adults with Down syndrome than for other adults with ID. The pattern of associated factors differs from that is found for other adults with ID, with few associations found. This suggests that the protection against mental ill-health is biologically determined in this population, or that there are other factors protective for mental ill-health yet to be identified for the population with Down syndrome.

Light-emitting Si-rich silicon nitride (SRN) films were fabricated by plasma enhanced chemical vapor deposition followed by low temperature (500–900°C) annealing. The optical properties of SRN films were studied by micro-Raman and photoluminescence spectroscopy and indicate the presence of small Si clusters characterized by broad near-infrared emission, large absorption/emission Stokes shift, and nanosecond recombination. Our results are supported by first-principles simulations indicating that N atoms bonded to the surface of nanometer Si clusters play a crucial role in the emission mechanism of SRN films. Light emission from SRN systems can provide alternative routes towards the fabrication of optically active Si devices.

not Available.

We employ density functional and quantum Monte Carlo calculations to show that significant changes occur in the optical gap of fully hydrogenated nanoclusters when the surface contains impurity passivants such as atomic oxygen. Our results show that quantum confinement is only one mechanism responsible for visible photoluminescence in silicon nanoclusters and that the specific surface chemistry must be taken into account in order to interpret experimental results. In the case of oxygen, the gap reduction computed as a function of the nanocluster size provides a consistent interpretation of several recent experiments. Furthermore, we predict that other double bonded groups also significantly affect the optical gap while single bonded groups have a minimal influence.

Unfortunately, major projects employing new technologies are extremely prone to cost and timescale overruns. It is believed that this is due to two main reasons. The first is the difficulty in preparing accurate estimates. The second is that the long development cycles allow time for market conditions and customer needs to change, and these changes inevitably add to the cost. This paper presents a practical discussion on the reasons why new technology projects are especially prone to cost overruns and how projects should manage the technology and surrounding issues. In particular, an appreciation of the capabilities and limitations of cost estimates by management may help to avoid some of the poor decision-making, which contributes to cost and schedule overruns. The paper discusses some of the ideas from project and risk management for effectively introducing new technology, helping projects to successfully meet the needs of both the customers and the project itself.

The ground state energy of the unpolarized homogeneous electron gas at zero temperature is calculated within the density range ${r}_{s}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.1--10$, incorporating relativistic effects via first-order perturbation theory. Accurate nonrelativistic wave functions and variational and diffusion quantum Monte Carlo techniques are used to calculate the required expectation values.

Quantum Monte Carlo (QMC) calculations are only possible in finite systems and so solids and liquids must be modeled using small simulation cells subject to periodic boundary conditions. The resulting finite-size errors are often corrected using data from local-density functional or Hartree-Fock calculations, but systematic errors remain after these corrections have been applied. The results of our jellium QMC calculations for simulation cells containing more than 600 electrons confirm that the residual errors are significant and decay very slowly as the system size increases. We show that they are sensitive to the form of the model Coulomb interaction used in the simulation cell Hamiltonian and that the usual choice, exemplified by the Ewald summation technique, is not the best. The finite-size errors can be greatly reduced and the speed of the calculations increased by a factor of 20 if a better choice is made. Finite-size effects plague most methods used for extended Coulomb systems and many of the ideas in this paper are quite general: they may be applied to any type of quantum or classical Monte Carlo simulation, to other many-body approaches such as the GW method, and to Hartree-Fock and density-functional calculations.

The grand challenges of contemporary fundamental physics-dark matter, dark energy, vacuum energy, inflation and early universe cosmology, singularities and the hierarchy problem-all involve gravity as a key component. And of all gravitational phenomena, black holes stand out in their elegant simplicity, while harbouring some of the most remarkable predictions of General Relativity: event horizons, singularities and ergoregions. The hitherto invisible landscape of the gravitational Universe is being unveiled before our eyes: the historical direct detection of gravitational waves by the LIGO-Virgo collaboration marks the dawn of a new era of scientific exploration. Gravitational-wave astronomy will allow us to test models of black hole formation, growth and evolution, as well as models of gravitational-wave generation and propagation. It will provide evidence for event horizons and ergoregions, test the theory of General Relativity itself, and may reveal the existence of new fundamental fields. The synthesis of these results has the potential to radically reshape our understanding of the cosmos and of the laws of Nature. The purpose of this work is to present a concise, yet comprehensive overview of the state of the art in the relevant fields of research, summarize important open problems, and lay out a roadmap for future progress. This write-up is an initiative taken within the framework of the European Action on 'Black holes, Gravitational waves and Fundamental Physics'., SCOPUS: re.j, info:eu-repo/semantics/published