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Numrering	Referens	Omslagsbild	Hitta
1.	Shen, Jingchun, et al. (författare) A Critical Review of Lighting Design and Asset Management Strategies. Illuminating Practices and Lessons Learned for Swedish Public Libraries 2023 Ingår i: Journal of Physics, Conference Series. - : Institute of Physics (IOP). - 1742-6588 .- 1742-6596. ; 2654:1 Konferensbidrag (refereegranskat)abstract Most lighting is only designed to meet the visual needs in most public library environments in Sweden. Although lighting-related impacts are relevant to six Unite Nations sustainability goals, some important lighting considerations, such as circadian phase disruption, mode and productivity impact, and energy-efficient operation, are missing in current lighting operating practices. Moreover, most of the current lighting asset management practice in public buildings remains "fix it if only it breaks". With respect to people-centric health factors, visual index, and lighting asset energy-efficient operation, this study sublimates lighting into a new perspective. Finally, the suggested comprehensive lighting operating strategies integrating digital twins can help designers and operators in defining the optimal design/control strategy in public-built environments, like public library. Digital twin-based decision-making is expected to be applied to lighting design and control in public spaces that improves visual acuity and comfort, positively impact mood and productivity, and provides recommendations on engagement principles under Environment Social Governance (ESG) framework to asset manager/operators.
2.	Carbone, Lisa, et al. (författare) Generators and relations for (generalised) Cartan type superalgebras 2019 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1194:1 Konferensbidrag (refereegranskat)abstract In Kac's classification of finite-dimensional Lie superalgebras, the contragredient ones can be constructed from Dynkin diagrams similar to those of the simple finite-dimensional Lie algebras, but with additional types of nodes. For example, A(n-1,0) = s (1\|n) can be constructed by adding a "gray" node to the Dynkin diagram of An-1 = s (n), corresponding to an odd null root. The Cartan superalgebras constitute a difierent class, where the simplest example is Wpnq, the derivation algebra of the Grassmann algebra on n generators. Here we present a novel construction of Wpnq, from the same Dynkin diagram as A(n-1,0), but with additional generators and relations.
3.	Goienetxea Uriarte, Ainhoa, 1983-, et al. (författare) System design and improvement of an emergency department using Simulation-Based Multi-Objective Optimization 2015 Ingår i: Journal of Physics, Conference Series. - : Institute of Physics Publishing (IOPP). - 1742-6588 .- 1742-6596. ; 616:1 Tidskriftsartikel (refereegranskat)abstract Discrete Event Simulation (DES) is nowadays widely used to support decision makers in system analysis and improvement. However, the use of simulation for improving stochastic logistic processes is not common among healthcare providers. The process of improving healthcare systems involves the necessity to deal with trade-off optimal solutions that take into consideration a multiple number of variables and objectives. Complementing DES with Multi-Objective Optimization (SMO) creates a superior base for finding these solutions and in consequence, facilitates the decision-making process. This paper presents how SMO has been applied for system improvement analysis in a Swedish Emergency Department (ED). A significant number of input variables, constraints and objectives were considered when defining the optimization problem. As a result of the project, the decision makers were provided with a range of optimal solutions which reduces considerably the length of stay and waiting times for the ED patients. SMO has proved to be an appropriate technique to support healthcare system design and improvement processes. A key factor for the success of this project has been the involvement and engagement of the stakeholders during the whole process.
4.	Stråhlman, Christian, et al. (författare) Negative-ion/positive-ion coincidence spectroscopy with a novel spectrometer 2015 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 635 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
5.	Nordebo, Sven, et al. (författare) Fisher information analysis and preconditioning in electrical impedance tomography 2010 Ingår i: Journal of Physics: Conference Series 224 (2010), 1742-6588. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; , s. 012057- Konferensbidrag (refereegranskat)abstract An adjoint field approach is used to formulate a general numerical framework for Fisher information based sensitivity analysis in electrical impedance tomography. General expressions are given for the gradients used in standard least squares optimization, i.e., the Jacobian related to the forward problem, and it is shown that these gradient expressions are consistent with commonly used electrode models such as the shunt model and the complete electrode model. By using the adjoint field formulations together with a variational analysis, it is also shown how the computation of the Fisher information can be integrated with the gradient calculations used for optimization. It is furthermore described how the Fisher information analysis and the related sensitivity map can be used in a preconditioning strategy to obtain a well balanced parameter sensitivity and improved performance for gradient based quasi-Newton optimization algorithms in electrical impedance tomography. Numerical simulations as well as reconstructions based on experimental data are used to illustrate the sensitivity analysis and the performance of the improved inversion algorithm in a four-electrode measurement set-up.
6.	Kamiya, Noriaki, et al. (författare) On $(\epsilon,\delta)$-Freudenthal Kantor triple systems and anti-structurable algebras with certain conditions 2012 Ingår i: Journal of Physics : Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 346 Konferensbidrag (refereegranskat)abstract In this paper we discuss a characterization of anti-structurable algebras in connection with their relation with $(-1,-1)$-Freudenthal Kantor triple systems.
7.	Sturesson, Peter, 1981-, et al. (författare) Thermomechanical stability and integrability of an embedded ceramic antenna with an integrated sensor element for wireless reading in harsh environments 2013 Ingår i: Journal of Physics: Conference Series. - London : IOP Publishing. - 1742-6588 .- 1742-6596. Konferensbidrag (refereegranskat)abstract This paper reports on the design, manufacturing and evaluation of a small, wirelessly powered and read resonating antenna circuit with an integrated pressure sensor. The work aims at developing miniature devices suitable for harsh environments, where high temperature prevents the use of conventional, silicon-based microdevices. Here, the device is made of alumina with platinum as conducting material. Ceramic green tapes were structured using high-precision milling, metallized using screen printing, and subsequently laminated to form stacks before they were sintered. The device's frequency shift as a function of temperature was studied up to 900°C. The contributions to the shift both from the thermomechanical deformation of the device at large, and from the integrated and, so far, self-pressurized sensor were sorted out. A total frequency shift of 3200 ppm was observed for the pressure sensor for heating over the whole range. Negligible levels of thermally induced radius of curvature were observed. With three-point bending, a frequency shift of 180 ppm was possible to induce with a curvature of radius of 220 m at a 10 N load. The results indicate that a robust pressure sensor node, which can register pressure changes of a few bars at 900°C and wirelessly transmit the signal, is viable.
8.	Boutachkov, P., et al. (författare) Isomer and Beta-decay Spectroscopy of Tz=1 Isotopes Below the N=Z=50 Shell Gap 2011 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 312:9 Tidskriftsartikel (refereegranskat)abstract The RISING setup at the GSI-FRS facility was used to investigate the isomer and beta decays in N~Z~50 Cd, Ag and Pd isotopes. A preliminary analysis of the data has revealed new results on the Tz=1, 94Pd, 96Ag and 98Cd isotopes. In 94Pd a new high-spin isomer was observed, whilst in 96Ag 3 new isomeric states were identified, including core-excited states. In 98Cd a new high-energy isomeric γ-ray transition is observed, thus enabling us to confirm the previous spin assignment for the core-excited 12+ isomer.
9.	Guastalla, G., et al. (författare) Analysis and Results of the 104Sn Coulomb Excitation Experiment 2014 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 533:1 Konferensbidrag (refereegranskat)abstract The analysis of the Coulomb excitation experiment conducted on 104Sn required a strict selection of the data in order to reduce the large background present in the gamma-ray energy spectra and identify the gamma-ray peak corresponding to the Coulomb excitation events. As a result the B(E2; 0 + -> 2+) value could be extracted, which established the downward trend towards 100Sn and therefore the robustness of the N=Z=50 core against quadrupole excitations.
10.	Wadsworth, R., et al. (författare) Spin-gap Isomer in 96Cd 2012 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 381:1 Tidskriftsartikel (refereegranskat)abstract Evidence has been obtained for the existence of the long predicted 16+ spin-gap isomer in 96Cd. The decay of the isomer was identified and studied following the use of an 850 MeV/u beam of 124Xe impinging on a Be target and the fragment recoil separator at the GSI Laboratory. Gamma decays from the fragments were detected using the RISING gamma ray array, in its stopped beam configuration, plus a silicon active stopper. The data obtained have been compared with shell model predictions, which indicate that the isoscalar neutron-proton interaction plays a key role in the formation of the isomer.
11.	Anttu, Nicklas, et al. (författare) Light scattering and plasmon resonances in a metal film with sub-wavelength nano-holes 2008 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 100, s. 052037-052037 Konferensbidrag (refereegranskat)abstract We report on a theoretical study of optical extinction in a metal film of 15-230 nm in thickness patterned periodically with sub-wavelength nano-holes of 140 nm in diameter. The gold plate was on a thick SiO2 wafer and the nano-holes as well as the top side of the metal plate were filled with water or solvent. Light was sent in toward the plate from the SiO2 side. The simulations were performed by solving the Maxwell equations using the scattering matrix method. It was seen that the extinction can, depending on the periodicity of the hole array, show one or several peaks in the visible wavelength range. The positions of the peaks were redshifted when the thickness of the gold plate was decreased. It was found that the peak positions for a thick plate can be identified from a simple surface plasmon dispersion relation.
12.	Constantinian, K. Y., et al. (författare) Electron transport and microwave dynamics of hybrid Nb/Au/CaSrCuO/YBaCuO planar Josephson junctions 2009 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 234:4, s. Art. no. 042004- Konferensbidrag (refereegranskat)abstract We report on measurements of dc electron transport and microwave dynamics of thin film hybrid Josephson junctions with an oxide antiferromagnetic interlayer. The base superconducting electrode YBaCuO and the antiferromagnetic (AF) interlayer CaSrCuO (with thickness d 20 - 70 nm) were grown by laser ablation on NdGaO3 substrates. I-V curves were well fitted to RSJ model and had no excess current, ICRN products were of order 0.2 mV at T=4.2 K. We did not observe any noticeable reduction of I CRN with increasing d. Such "tunnellike" behaviour also resulted in appearance of singularities on I-V curve when magnetic field was applied. Oscillating with microwave power integer and half-integer Shapiro steps were registered along with sub-harmonic detector response. Moreover, for some of junctions a "devil" staircase structure was observed on I-V curves and giant noise-like signals were measured in 1-2 GHz band at the certain levels of microwave power. Observed features, noise performance and the impact of the second harmonic in current-phase relation on junction dynamics are discussed taking into account data for structures without AF interlayer.
13.	Espinoza-Andaluz, Mayken, et al. (författare) Applicability of the lattice Boltzmann method to determine the ohmic resistance in equivalent resistor connections 2017 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 936:1 Tidskriftsartikel (refereegranskat)abstract Knowing the ohmic resistance in the materials allow to know in advance its electrical behavior when a potential difference is applied, and therefore the prediction of the electrical performance can be achieved in a most certain manner. Although the Lattice Boltzmann method (LBM) has been applied to solve several physical phenomena in complex geometries, it has only been used to describe the fluid phase, but applicability studies of LBM on the solid-electric-conducting material have not been carried out yet. The purpose of this paper is to demonstrate the accuracy of calculating the equivalent resistor connections using LBM. Several series and parallel resistor connections are effected. All the computations are carried out with 3D models, and the domain materials are designed by the authors.
14.	Flechl, Martin, et al. (författare) Grid interoperability : joining grid information systems 2007 Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 119:6, s. 062030- Tidskriftsartikel (refereegranskat)abstract A grid is defined as being 'coordinated resource sharing and problem solving in dynamic, multi-institutional virtual organizations'. Over recent years a number of grid projects, many of which have a strong regional presence, have emerged to help coordinate institutions and enable grids. Today, we face a situation where a number of grid projects exist, most of which are using slightly different middleware. Grid interoperation is trying to bridge these differences and enable Virtual Organizations to access resources at the institutions independent of their grid project affiliation. Grid interoperation is usually a bilateral activity between two grid infrastructures. Recently within the Open Grid Forum, the Grid Interoperability Now (GIN) Community Group is trying to build upon these bilateral activities. The GIN group is a focal point where all the infrastructures can come together to share ideas and experiences on grid interoperation. It is hoped that each bilateral activity will bring us one step closer to the overall goal of a uniform grid landscape. A fundamental aspect of a grid is the information system, which is used to find available grid services. As different grids use different information systems, interoperation between these systems is crucial for grid interoperability. This paper describes the work carried out to overcome these differences between a number of grid projects and the experiences gained. It focuses on the different techniques used and highlights the important areas for future standardization.
15.	Folsom, B., et al. (författare) Approximating nonlinear forces with phase-space decoupling 2017 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 874:1 Tidskriftsartikel (refereegranskat)abstract Beam tracking software for accelerators typically falls into two categories: fast envelope simulations limited to linear beam optics, and slower multiparticle simulations that can model nonlinear effects. To find a middle ground between these approaches, we introduce virtual coordinates in position and momentum which have a cross-dependency (i.e. p∗ = f (x 0) where x 0 is an initial position and p∗ is a virtual projection of momentum onto the position axis). This technique approximates multiparticle simulations with a significant reduction in calculation cost.
16.	Fynbo, H. O. U., et al. (författare) The Î²-decay approach for studying 12C 2008 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 111:1 Tidskriftsartikel (refereegranskat)abstract The Î²-decays of the mirror nuclei 12B and 12N both populate states in 12C and they are therefore a precious source of information about this nucleus. Due to the selection rules of Î²-decay only 0+, 1+ and 2+ states are populated. This allows a very clean study of unbound states just above the 3Î±-threshold with those spin and parities. This probe has been applied in two experiments using two complementary experimental techniques: in the first the three Î±-particles emitted after Î²-decay are measured in coincidence in separate detectors using the ISOL method, while in the second method 12B and 12N are implanted in a detector and the summed energy of the three Î±-particles is measured directly. Preliminary results from the two approaches are presented. Â© 2008 IOP Publishing Ltd.
17.	Ghasempour, Farideh, 1981, et al. (författare) Multidimensional turbulence spectra – identifying properties of turbulent structures 2011 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 318:4, s. 042022- Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract Development of models for several phenomena occurring in turbulent single and multiphase flows requires improved description and quantification of the turbulent structures. This is needed since often the phenomena are very fast or nonlinear. Previously the authors have presented experimental measurements that show that the breakup of bubbles and drops in turbulence is due to interaction with single turbulent vortices. Hence, it is not sufficient to use average turbulence properties when developing models for CFD simulation of engineering applications. In this paper the results from analysis of individual turbulent structures are presented. Results from analysis of the turbulent kinetic energy in turbulent structures, using Eulerian vortex identification methods, are presented. The amount of turbulent kinetic energy associated with a coherent vortex defined using different vortex identification methods is quantified. It is shown that the peak turbulent kinetic energy is located near the edge of the region identified as coherent, making the analysis challenging and development of models difficult. However, detailed analysis of a small number of coherent vortices from LES of turbulent pipe flow reveals new information about their life history. The growth (i.e. entrainment of the surrounding liquid), enstrophy, lifetime, and energy of a specific coherent vortex are tracked over time.
18.	Gustafsson, Anders, et al. (författare) GaAs-based Nanowires Studied by Low-Temperature Cathodoluminescence 2011 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 326, s. 012042-012042 Konferensbidrag (refereegranskat)abstract We present cathodoluminescence data of nanowires (NWs) grown using size-selected gold particles as seeds. The NWs have a GaAs core with a diameter of 50 nm and a length of several mu m. The NWs in this study were generally covered with a shell of AlGaAs. With increasing growth temperature, the emission intensity increases significantly. From a variety of growth conditions, we conclude that the exposed sides of the NWs during growth play an important role in the emission intensity. The diffusion of carriers was studied by inserting a segment of GaInAs in GaAs NWs. By capping the NWs with an AlGaAs shell, we observe a tenfold increase in the diffusion length along the core.
19.	Halvarsson, Mats, 1965, et al. (författare) Thin foil analysis in the SEM 2008 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 126, s. 4- Tidskriftsartikel (refereegranskat)abstract This paper explores the possibilities for imaging and chemical analysis of thin foil specimens in the SEM. Bright field and dark field imaging provide high resolution imaging with crystallographic information within the grains. In multiphase materials with varying electron transmission the dark field images generally provide a more even contrast in all phases. It is possible to obtain high-quality quantitative EDX data with high spatial resolution.
20.	Joshi, N., et al. (författare) MEMS Based Micro Aerial Vehicles 2016 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 757:1 Konferensbidrag (refereegranskat)abstract Designing a flapping wing insect robot requires understanding of insect flight mechanisms, wing kinematics and aerodynamic forces. These subsystems are interconnected and their dependence on one another affects the overall performance. Additionally it requires an artificial muscle like actuator and transmission to power the wings. Several kinds of actuators and mechanisms are candidates for this application with their own strengths and weaknesses. This article provides an overview of the insect scaled flight mechanism along with discussion of various methods to achieve the Micro Aerial Vehicle (MAV) flight. Ongoing projects in Chalmers is aimed at developing a low cost and low manufacturing time MAV. The MAV design considerations and design specifications are mentioned. The wings are manufactured using 3D printed carbon fiber and are under experimental study. © Published under licence by IOP Publishing Ltd.
21.	Kawabata, Shiro, et al. (författare) Theory of two-dimensional macroscopic quantum tunneling in a Josephson junction coupled with an LC circuit 2009 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 150:5, s. 052105- Konferensbidrag (refereegranskat)abstract We investigate classical thermal activation (TA) and macroscopic quantum tunneling (MQT) for a Josephson junction coupled with an LC circuit theoretically. The TA and MQT escape rate are calculated analytically by taking into account the two-dimensional nature of the classical and quantum phase dynamics. We find that the MQT escape rate is largely suppressed by the coupling to the LC circuit. On the other hand, this coupling gives rise to slight reduction of the TA escape rate. These results are relevant for the interpretation of a recent experiment on the MQT and TA phenomena in grain boundary YBCO Josephson junctions.
22.	Kómár, A, et al. (författare) Interaction of electromagnetic waves and suprathermal electrons in the near-critical electric field limit 2012 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 401:1 Konferensbidrag (refereegranskat)abstract The velocity-space anisotropy of suprathermal electron distributions is a source of free energy that may destabilize plasma waves through a resonant interaction between the waves and the energetic electrons. In this work we use a suprathermal electron distribution appropriate for the case when the accelerating electric field is near-critical and we investigate the frequencies, wave numbers and propagation angles of the most unstable waves using a general dispersion relation. It is shown that if the electric field is sub-critical, the anisotropy is not enough to drive electromagnetic waves unstable, as the Landau damping of the waves overwhelms the drive through the anomalous Doppler resonance. In the case when the electric field is supercritical, two types of electromagnetic waves will be destabilized, the electron-whistler and the extraordinary electron wave. The number of electrons for destabilization of the latter is several orders of magnitude lower than for the electron-whistler wave. Consequently, the threshold for destabilization of the extraordinary electron wave is much lower.
23.	Lenz, Annika, et al. (författare) Quantum-chemical investigations of phenol and larger aromatic molecules at the TiO2 anatase (101) surface 2008 Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 117, s. 012020-(8 pp) Tidskriftsartikel (refereegranskat)abstract Adsorption of aromatic molecules at the (101) surface of titanium dioxide anatase is studied by quantum-chemical B3LYP computations, where both cluster and periodic calculations were performed and compared. For phenol different adsorption modes at a TiO2 cluster were mapped out and the energetically most favourable conformation was used for investigation of the electronic structure, for periodic calculations, and as a mould for the adsorption modes of phenylmethanol, phenylethanol, naphthalen-2-ol, phenanthren-2-ol, pyren-2-ol and perylen-2-ol. The alcohols form a H-bond to a surface O and a O(molecule)-Ti bond. For the larger aromatic molecules their increasingly higher HOMO levels decrease the effective bad gap of the system. Inclusion of spacer groups as in phenylmethanol and phenylethanol results in higher adsorption energies and larger band gaps. The LUMOs for the adsorbates help visualize the electronic coupling to the surface. Comparison of the cluster with the periodic model indicates that the former describes the electronic coupling in a similar manner as the latter, although the former lacks in the description of the anatase substrate.
24.	Madurga, M., et al. (författare) Study of Î²-delayed charged particle emission of 11Li: Evidence of new decay channels 2008 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 111:1 Tidskriftsartikel (refereegranskat)abstract The break-up of the 18.2 MeV state in 11Be was studied in a 11Li Î²-decay experiment. We report here on the study of the dominating breakup channels involving na6He or 3n2Î± in the final state, with special emphasis dedicated in this contribution to the three-particle channel. The two emitted charged particles were detected in coincidence using a highly segmented experimental set-up. The observed experimental energy-vs-energy scatter plot indicates a sequential breakup where nuclei of mass 4, alpha particles, and mass 7, 7He, are involved. A Monte-Carlo simulation of the sequential channel, 11Be* â†’ Î± + 7He â†’ nÎ±6He was performed and compared to the experimental data and to a simulation of the direct break-up of the 18.2 MeV state nÎ±6He by phase space energy distribution. The energy-versus-energy plot are explained by the sequential simulation but not by the phase space simulation.
25.	Maercker, Matthias, 1979 (författare) ALMA observations of the not-so detached shell around the carbon AGB star R Sculptoris 2016 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 728:2, s. Aricle no. 022006- Konferensbidrag (refereegranskat)abstract I present our ALMA observations of the CO emission around the carbon AGB star R Sculptoris. The data reveal the known detached shell and a previously unknown, binary induced, spiral shape. The observations confirm a formation of the shell during a thermal pulse about 2300 years ago. The full analysis of the ALMA data shows that the shell around R Scl in fact is entirely filled with molecular gas, and hence not as detached as previously thought. This has implications for the mass-loss rate evolution immediately after the pulse, indicating a much higher mass-loss rate than previously assumed. Comparing the ALMA images to our optical observations of polarised, dust scattered light, we further show that the distributions of the dust and gas coincide almost perfectly, implying a common evolution of the dust and gas, and constraining the wind-driving mechanism. The mass-loss process and amount of mass lost during the thermal pulse cycle affect the chemical evolution of the star, its lifetime on the AGB, and the return of heavy elements to the ISM. New high-resolution ALMA observations constrain the parameters of the binary system and the inner spiral, and will allow for a detailed hydrodynamical modelling of the gas and dust during and after the last thermal pulse. Our results present the only direct measurements of the thermal pulse evolution currently available. They greatly increase our understanding of this fundamental period of stellar evolution, and the implications it has for the chemical evolution of evolved stars, the ISM, and galaxie.
26.	Mantulnikovs, K., et al. (författare) Neutron guide shielding for the BIFROST spectrometer at ESS 2016 Ingår i: VI European Conference On Neutron Scattering (ECNS2015). - : IOP Publishing. ; 746:1 Konferensbidrag (refereegranskat)abstract We report on the study of fast-neutron background for the BIFROST spectrometer at ESS. We investigate the effect of background radiation induced by the interaction of fast neutrons from the source with the material of the neutron guide and devise a reasonable fast, thermal/cold neutron shielding solution for the current guide geometry using McStas and MCNPX. We investigate the effectiveness of the steel shielding around the guide by running simulations with three different steel thicknesses. The same approach is used to study the efficiencies of the steel wall a flat cylinder pierced by the guide in the middle and the polyethylene layer. The final model presented here has a 3 cm thick steel shielding around the guide, 30 cm of polyethylene around the shielding, two 5 mm thick B4C layers and a steel wall at position Z = 38 m, being 1 m thick and 10 m in radius. The final model finally proves that it is sufficient to bring the background level below the cosmic neutron rate, which defines an order of magnitude of the lowest obtainable background in the instruments.
27.	Nystedt, Fredrik (författare) On the Use of Risk Concepts in Fire Safety Engineering 2018 Ingår i: 3rd European Symposium on Fire Safety Science 12–14 September 2018, Nancy, France. - : IOP Publishing. - 1742-6588. ; 1107 Konferensbidrag (refereegranskat)abstract Design for fire safety may be carried out by two generic approaches - a set of prescriptive rules or by a performance-based approach where analytical tools are used to verify fire safety towards a set of functional requirements and performance criteria given by the building code. Normally, these two methods are mixed when design fire safety within a building. The option to apply fire safety engineering to the design of buildings has been available during the last 20 to 40 years, depending on which aspect of fire safety being considered. Still, the fire protection of a building too often relies on general recommendations rather than scientifically-based solutions, due to a lack of standardised verification methods, acceptance criteria and procedures to ensure high quality fire safety design. The concept of risk, i.e. the combination of the probability of a fire and a quantified measure of its consequence, has been thoroughly investigated in several fire safety engineering applications over the last decades. Although there are techniques available that allow designers to evaluate fire risks, risk acceptance criteria are missing in general. Structural fire safety design is the exemption having defined target reliabilities. Although these criteria only address the likelihood of collapse of structural element and not explicitly the characteristics of the failure. Structural elements can be provided with fire resistance to control the spread of fire or to prevent structural collapse, or both and it is not uncommon to perform trade-offs between passive and active fire protection systems. But, very little effort has previously been made to understand the fundamental differences between these systems regarding their reliability and failure modes. Performance-based design of structural elements uses a heat exposure model to quantify the thermal load of the fire. The thermal load is characterised by the fire load (duration) and the intensity (air supply). Characteristic values of the fire load are found in various sources and commonly given in the building code, which ought to be used when designing for fire safety. A probabilistic approach was introduced in the 1980s where the probability of fire is expressed as a function of the probability of fire occurrence, the probability of a flashover and the probability of failure given a fully developed fire. Thus, the target probability of failure could be achieved by applying safety measures that alters the probability of any of these events. Currently, fire sprinklers do allow for a reduction in design fire load, but not other active safety system can be considered explicitly. Passive as well as active system for fire safety could both be considered as appropriate provisions to achieve sufficient safety. Even though there are support of trade-offs between passive and active provisions, current regulations, guidance as well as practise do not treat the different aspect of risk related to these systems. By only considering the probability of collapse, the design could deviate from overall societal requirements on avoiding catastrophes or principles of robustness stating that consequences should not be disproportionate to their cause. Traditionally, passive systems are assumed more robust. These findings are probably related to the concepts where target reliabilities are evaluated as the system is designed. Sprinklers are, on the other hand, assigned a probability of successful operation based on decades of statistics. This is an unfair comparison between the systems as a properly design sprinkler system always would prevent a fully developed fire, thus requiring no specific fire resistance on separating and structural elements. Naturally, this is not the path forward as the failure modes of both types of system must be treated and understood. Active systems could be argued to be more forgiven as the they do not care what mistakes are made to cause a fire, neither do they care if occupants act as planed or not. Passive systems are more sensitive to building use when e.g. doors are kept open. Future performance criteria and risk acceptance criteria should not focus solely on probabilities. Emphasis must be put on establish criteria that measure the risk of the unwanted event considering type of initiating event, number of barriers, expected consequence, possibility of damage control, etc. Not until such criteria are available the full potential of performance-based fire safety design cannot be utilised.
28.	Puig von Friesen, Marc, et al. (författare) Artificial damping in the Kadanoff-Baym dynamics of small Hubbard chains 2010 Ingår i: Progress in Nonequilibrium Green's Functions IV (Journal of Physics: Conference Series). - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 220, s. 012016-012016 Konferensbidrag (refereegranskat)abstract We perform a comparative study of exact and approximate time-evolved densities in small Hubbard chains. The approximate densities are obtained via many-body perturbation theory (Hartree-Fock, 2(nd) Born, GWand T-matrix approximations) within the framework of the time-dependent Kadanoff-Baym equations. Benchmarking approximate results against exact ones allows us to address two rather fundamental issues in the non equilibrium dynamics of strongly correlated systems. I) A characterisation of the performance of several standard MBAs in the non-equilibrium regime. Having a definite notion of how good a specific MBA can be is highly relevant to its application to cases (typically, infinite systems) where exact solutions are not available. Our results show that the T-matrix approximation is overall superior to the other MBAs, at all electron densities. II) A scrutiny of the whole idea of Many Body Perturbation Theory in the Kadanoff-Baym sense, when applied to finite systems. The surprising outcome of our study is that during the time evolution, the KBE develop an unphysical steady state solution. This is a genuinely novel feature of the time-dependent KBE, i.e. is not inherited from possible limitations/approximations in the calculation of the initial state. Our extensive numerical characterisation gives robust evidence that the problem occurs in general, whenever MBPT is applied to finite systems, and approximate self energies based upon infinite partial summations are used. We also offer some more conceptual and general consideration on the dependence of this behaviour on the number of particles and system size. This is followed by our conclusions and glimpses of future work.
29.	Rodriguez, D. Martin, et al. (författare) How to polarise all neutrons in one beam : a high performance polariser and neutron transport system 2016 Ingår i: VI European Conference On Neutron Scattering (ECNS2015). - : IOP Publishing. ; 746:1 Konferensbidrag (refereegranskat)abstract Polarised neutron beams are used in disciplines as diverse as magnetism, soft matter or biology. However, most of these applications often suffer from low flux also because the existing neutron polarising methods imply the filtering of one of the spin states, with a transmission of 50% at maximum. With the purpose of using all neutrons that are usually discarded, we propose a system that splits them according to their polarisation, flips them to match the spin direction, and then focuses them at the sample. Monte Carlo (MC) simulations show that this is achievable over a wide wavelength range and with an outstanding performance at the price of a more divergent neutron beam at the sample position.
30.	Rosen, Bengt-Göran, 1962, et al. (författare) Topographic modelling of haptic properties of tissue products 2014 Ingår i: Journal of Physics: Conference Series. - Bristol : IOP Publishing. - 1742-6588 .- 1742-6596. ; 483:1 Konferensbidrag (refereegranskat)abstract The way a product or material feels when touched, haptics, has been shown to be a property that plays an important role when consumers determine the quality of products For tissue products in constant touch with the skin, softness becomes a primary quality parameter. In the present work, the relationship between topography and the feeling of the surface has been investigated for commercial tissues with varying degree of texture from the low textured crepe tissue to the highly textured embossed- and air-dried tissue products. A trained sensory panel at was used to grade perceived haptic «roughness». The technique used to characterize the topography was Digital light projection (DLP) technique, By the use of multivariate statistics, strong correlations between perceived roughness and topography were found with predictability of above 90 percent even though highly textured products were included. Characterization was made using areal ISO 25178-2 topography parameters in combination with non-contacting topography measurement. The best prediction ability was obtained when combining haptic properties with the topography parameters auto-correlation length (Sal), peak material volume (Vmp), core roughness depth (Sk) and the maximum height of the surface (Sz). © Published under licence by IOP Publishing Ltd.
31.	Rossander, Morgan, 1981-, et al. (författare) Frequency analysis of tangential force measurements on a vertical axis wind turbine 2016 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. Konferensbidrag (refereegranskat)abstract This paper presents experimental results of the torque ripple obtained from a three bladed 12 kW experimental H-rotor prototype. The measurements are performed by means of load cells installed on the base of the struts and by electrical measurements on the generator. The resulting torques are analysed in terms of frequency spectrum and order spectrum (synchronized with rotation). The measurements are compared to aerodynamic simulations of the turbine. The expected large torque ripple at three times the rotational speed (3 p) is only weakly represented at the hub and in the generator. This suggests that the system is filtering the ripple and/or that the simulations are overestimating the 3 p component. The torque ripple loads on the drive train are therefore lower than anticipated. Even if highly attenuated, most of the low frequencies correlating to aerodynamics are still represented in the generator electrical torque. Given a certain baseline, this opens for possible online monitoring of unbalances in the turbine by electrical measurements.
32.	Skjolding, Lars Henrik, et al. (författare) Characterisation of nano-interdigitated electrodes 2008 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 100, s. 052045-052045 Konferensbidrag (refereegranskat)abstract Interdigitated electrodes made up of two individually addressable interdigitated comb-like electrode structures have frequently been suggested as ultra sensitive electrochemical biosensors. Since the signal enhancement effects due to cycling of the reduced and oxidized species are strongly dependent on the inter electrode distances, since the nature of the enhancement is due to overlying diffusion layers, inter digitated electrodes with an electrode separation of less the non emicrometer a redesired for maximum signal amplification. Fabrication of submicron structures can only be made by advanced lithography techniques. By use of electron be amlithography we have fabricated arrays of interdigitated electrodes with an electrode separation distance of 200nm and an electrode finger width of likewise 200nm. The entire electrode structure is 100 micrometre times 100 micrometre, and the active electrode area is dictated by the opening in the passivation layer, that is defined by UV lithography. Here we report measurements of redox cycling of ferrocyanide by coupled cyclic voltammograms, where the potential atone of the working electrodes are varied and either an oxidising or reducing potential is applied to the complimentary interdigitated electrode. The measurements show fast conversion and high collection efficiency round 87% as expected for nano-interdigitated electrodes.
33.	Stråhlman, Christian, et al. (författare) Angle-resolved time-of-flight spectroscopy applied to multi-bunch operation at MAX-lab: a design study 2013 Ingår i: IOP Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 425 Konferensbidrag (refereegranskat)abstract Angle-resolved time-of-flight (ARTOF) spectrometers have found use in a number of applications, including ARPES. However, the fundamental requirement of an external start trigger matching the read-out time of the instrument limits its usability at many storage rings. Hitherto all reported experiments have been performed at storage rings capable of running in single-bunch mode. To eliminate this restriction, we propose a method where a pulsed electronic gate is introduced to allow for ARTOF usage at normal multi-bunch operation of the MAX II storage ring. This paper will show the working principle and outline the design for this technique.
34.	Thunnissen, Marjolein, et al. (författare) BioMAX: The Future Macromolecular Crystallography Beamline at MAX IV 2013 Ingår i: 11th International Conference on Synchrotron Radiation Instrumentation (SRI 2012). - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 425 Konferensbidrag (refereegranskat)abstract This paper describes the preliminary design of the BioMAX beamline at the 3 GeV ring of the MAX IV facility, focusing on the optics and x-ray beam performance. The MAX IV facility will include two storage rings with 1.5 GeV and 3.0 GeV electron energy and a linac serving both as injector for the two rings and feeding a short pulse facility. BioMAX is one of the first seven beamlines funded at the MAX IV facility. It is a multipurpose high-throughput beamline for macromolecular crystallography. The beamline aims to be robust and simple to operate with a beam benefiting from the properties of the MAX IV 3 GeV ring. However it does not aim at the smallest beam or crystal sizes since it is foreseen that it will be complemented with a microfocus beamline aiming at a beam size of 1 mu m. The beamline experiment setup will be highly automated, both in terms of sample handling hardware and data analysis, including feedback to the data collection. The BioMAX beamline is planned to be in operation in 2016.
35.	Varvarezos, Lazaros, et al. (författare) Intensity-dependent near-threshold ionization of Kr in the vacuum-uv 2019 Ingår i: International Conference on Spectral Lines Shapes. - : IOP Publishing. - 1742-6588. ; 1289 Konferensbidrag (refereegranskat)abstract In this work, we present measurements of the intensity-dependent photoelectron spectrum of Kr irradiated by the FLASH FEL tuned to a photon energy of 25.8 eV. Intensity dependent photoelectron spectra were obtained with the aid of a Velocity Map Imaging (VMI) spectrometer. As the FEL photon energy is close to threshold, two photon sequential double ionization is favoured. The number of open channels is kept to a minimum and leading to a simple description of the process.
36.	Häggström, Lennart, et al. (författare) Thickness dependent crystallographic transition in Fe/Ni multilayers 2010 Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 217, s. 012112- Tidskriftsartikel (refereegranskat)abstract The crystallog. transition between bcc- and fcc-structures has been studied in Fe/Ni multilayers with Moessbauer spectroscopy and X-ray diffraction. Layered structures have been confirmed and the structures depends both on individual layer thickness and the ratio of the constituents. Two sets of samples are made: the Fe layer thickness kept const. to 12 monolayer (ML) and 24ML, while the Ni layer thicknesses varied from 3 to 12ML. When the Ni layer is thin, the Fe/Ni multilayers have the bcc phase. When the thickness of Ni layer reaches 6ML and larger, a gradual transition to the fcc phase occurs. Moessbauer spectroscopy studies confirm the existence of a magnetic Fe bcc phase with in-plane magnetization in all samples, two magnetic fcc phases with fields of 28 T and 10 T and small amts. of nonmagnetic fcc phases in the thicker films. The obsd. behavior can be attributed to the existence of two types of interfaces which are not necessary overlapping each other: An elemental interface between Fe and Ni and a structural interface between fcc and bcc phases. [on SciFinder(R)]
37.	Larson, Åsa, et al. (författare) Ion-pair formation in electron recombination with molecular ions 2007 Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 88, s. 012065-1-012065-8, s. 012065- Tidskriftsartikel (refereegranskat)abstract By studying ion-pair formation in electron recombination with molecular ions,fundamental knowledge on the molecular dynamics can be obtained. In order to study thesetypes of reactions, both the electron recombination as well as the dynamics all the way to theasymptotic limits must be well described. We have used the wave packet technique to studyion-pair formation in electron recombination with HeH+, HD+, H3+ and HF+. We here discusswhat will determine the general shape of the ion-pair cross section, the threshold effects, possibleinterference effects as well as the ratio of the cross sections of ion-pair formation to dissociativerecombination.
38.	Shestopalov, Yury, 1953-, et al. (författare) Inverse scattering in guides 2012 Ingår i: Journal of Physics, Conference Series. - Philadelphia : Institute of Physics Publishing (IOPP). - 1742-6588 .- 1742-6596. ; 346, s. 012019-1-012019-13 Tidskriftsartikel (refereegranskat)abstract We present statements and a method of solution to the inverse scattering problem of reconstructing permittivity of a dielectric inclusion in a 2D or 3D waveguide from thetransmission characteristics. The approach employs a volume singular integral equation (VSIE) method. The unique solvability of VSIE is established. The inverse problem is solved by themethod of iterations applied to VSIE; the convergence of the method is proved
39.	Khrennikov, Andrei, 1958- (författare) Measurement problem : from De Broglie to theory of classical random fields interacting with threshold detectors 2013 Ingår i: Journal of Physics, Conference Series. - : Institute of Physics (IOP). - 1742-6588 .- 1742-6596. ; 442, s. Article ID: 012011- Tidskriftsartikel (refereegranskat)abstract The quantum measurement problem as was formulated by von Neumann in 1933 can be solved by going beyond the operational quantum formalism. In our "prequantum model" quantum systems are symbolic representations of classical random fields. The Schrödinger's dynamics is a special form of the linear dynamics of classical fields. Measurements are described as interactions of classical fields with detectors. Discontinuity, the "collapse of the wave function", has the trivial origin: usage of threshold type detectors. The von Neumann projection postulate can be interpreted as the formal mathematical encoding of the absence of coincidence detection in measurement on a single quantum system, e.g., photon's polarization measurement. Our model, prequantum classical statistical field theory (PCSFT), in combination with measurements by threshold detectors satisfies the quantum restriction on coincidence detections: the second order coherence is less than one (opposite to all known semiclassical and classical feld models). The basic rule of quantum probability, the Born's rule, is derived from properties of prequantum random felds interacting with threshold type detectors. Comparison with De Broglie's views to quantum mechanics as theory of physical waves with singularities is presented.
40.	Macias, Raul, et al. (författare) Performance of the Load-in-the-Loop Single Op-Amp Voltage Controlled Current Source from the Op-Amp Parameters 2010 Ingår i: Journal of Physics: Conference Series. - : Institute of Physics Publishing Ltd.. - 1742-6596 .- 1742-6588. Konferensbidrag (refereegranskat)abstract In recent years, Electrical Bioimpedance (EBI) methods have gained importance. These methods are often based on obtaining impedance spectrum in the range of β-dispersion, i.e. from a few kHz up to some MHz. To measure EBI a constant current is often injected and the voltage across the tissue under study (TUS) is recorded. Due to the performance of the current source influences the performance of the entire system, in terms of frequency range, several designs have been implemented and studied. In this paper the basic structure of a Voltage-Controlled Current Source (VCCS) based on a single Op-Amp in inverter configuration with a floating load, known as load-in-the-loop current source, is revisited and studied deeply. We focus on the dependence of the output impedance with the circuit parameters, i.e. the feedback resistor and the inverter-input resistor, and the Op-Amp main parameters, i.e. open loop gain, CMRR and input impedance. After obtaining the experimental results and comparing to the theoretical and simulated ones, they confirm the design under study can be a good solution for multi-frequency wideband EBI applications because of higher values of the output impedance than 100kΩ at 1MHz are obtained. Furthermore, an enhancement of the basic design, using a current conveyor as a first stage, is proposed, studied and implemented.
41.	Yanson, I. K., et al. (författare) Vortex-like state observed in ferromagnetic contacts 2010 Ingår i: Journal of Physics: Conference Series. - : Institute of Physics Publishing (IOPP). - 1742-6588 .- 1742-6596. ; 200:5, s. 1-4 Tidskriftsartikel (refereegranskat)abstract Point-contacts (PC) oﬀer a simple way to create high current densities, 109 A/cm 2and beyond, without substantial Joule heating. We have shown recently (Nano Letters, 7(2007) 927) that conductivity of nanosized PCs between a normal and ferromagnetic metalsexhibits bi-stable hysteretic states versus both bias current and external magnetic ﬁeld – theeﬀect typical for spin-valve structures. Here we report that apart from the bi-stable state athird intermediate-resistance state is occasionally observed. We interpret this state as due toa spin-vortex in the PC, nucleated either by Oersted ﬁeld of the bias current and/or by thecircular geometry of PC. The observed three-level-states in the PC conductivity testify that theinterface spins are both weakly coupled to the spins in the bulk and have depressed exchangeinteraction within the surface layer.
42.	Alcorta, M., et al. (författare) Properties of resonances in 12C above the triple-alpha threshold 2011 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 312:SECTION 9, s. Art. no. 092013- Konferensbidrag (refereegranskat)abstract A complete kinematics study of the 10B(3He, pααα) and the 11B(3He, dααα) reactions has been performed to study the multi-particle break-up of 12C resonances above the triple-alpha threshold. The values of energy and widths of some states has been improved, and in states of natural parity partial branches of decay through the ground state of 8Be have been extracted. The influence of the "ghost" of the 8Be ground state has been taken into account in order to clarify the partial branches.
43.	Aldén, Marcus (författare) Development and applications of laser spectroscopic techniques related to combustion diagnostics 2006 Ingår i: Second International Conference on Optical and Laser Diagnostics. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 45, s. 18-18 Konferensbidrag (refereegranskat)abstract Thanks to features as non-intrusiveness combined with high spatial and temporal resolution, various laser diagnostic techniques have during the last decades become of utmost importance for characterization of combustion related phenomena. In the following presentation some further development of the techniques will be highlighted aiming at a) surface temperatures using Thermographic Phosphors, TP, b) species specific, spatially and temporally resolved detection of species absorbing in the IR spectral region using polarization spectroscopy and Laser-induced fluorescence, and finally c) high speed visualization using a special designed laser system in combination with a framing camera. In terms of surface thermometry, Thermographic Phosphors have been used for many years for temperature measurements on solid surfaces. We have during the last years further developed and applied this technique for temperature measurements on burning surfaces and on materials going through phase shifts, e.g. pyrolysis and droplets. The basic principle behind this technique is to apply micron size particles to the surface of interest. By exciting the TP with a short pulse UV laser (ns), the phosphorescence will exhibit a behaviour where the spectral emission as well as the temporal decay are dependent on the temperature. It is thus possible to measure the temperature both in one and two dimensions. The presentation will include basic description of the technique as well as various applications, e.g in fire science, IC engines and gasturbines. Several of the species of interest for combustion/flow diagnostics exhibit a molecular structure which inhibits the use of conventional laser-induced fluorescence for spatially and spectrally resolved measurements. We have during the last years investigated the use of excitation and detection in the infrared region of the spectrum. Here, it is possible to detect both carbonmono/dioxide, water as well as species specific hydrocarbons. The techniques which have been investigated are laser-induced fluorescence and polarization spectroscopy. In the latter case several species have been detected both in free flows as well as flames, e.g in addition to water and carbondioxide also the hydroxyl radical and different hydrocarbons including methane, acetylene, ethane and the methyl radical. One parameter of utmost importance for visualization combustion/flow phenomena is the possibility to make this visualization in real time with adequate time resolution. We have for several years developed and applied a special designed laser/detector system for high repetition rate measurements which has been applied for several real-world applications, e.g internal combustion engines. The system can also be used for three dimensional visualization by sweeping the laser pulses through the region of interest and consequent detection with the framing camera. Also in this case experiment from industrial applications will be exemplified.
44.	Almbladh, Carl-Olof (författare) Photoemission beyond the sudden approximation 2006 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 35:1, s. 127-144 Konferensbidrag (refereegranskat)abstract The many-body theory of photoemission in solids is reviewed with emphasis on methods based on response theory. The classification of diagrams into loss and no-loss diagrams is discussed and related to Keldysh path-ordering book-keeping. Some new results on energy losses in valence-electron photoemission from free-electron-like metal surfaces are presented. A way to group diagrams is presented in which spectral intensities acquire a Golden-Rule-like form which guarantees positiveness. This way of regrouping should be useful also in other problems involving spectral intensities, such as the problem of improving the one-electron spectral function away from the quasiparticle peak
45.	Almqvist, Monica, et al. (författare) Ultrasound field characterisation in air using light diffraction tomography 2004 Ingår i: AMUM 2004: Advanced Metrology for Ultrasound in Medicine 2004. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 1, s. 150-154 Konferensbidrag (refereegranskat)abstract The aim of this work was to show the applicability of light diffraction tomography on airborne ultrasound. Different air-coupled transducers in the frequency range 40 kHz - 2 MHz were measured to show the method's performance. A calibrated microphone and the pulse-echo method were used to evaluate the results. The absolute measurements agreed within the calibrated microphone's uncertainty range. Pulse waveforms and corresponding FFT-diagrams show the method's higher bandwidth compared to the microphone. Further, the method offers non-perturbing measurements with high spatial resolution, which was especially advantageous for measurements close to the transducer surfaces. The S/N-ratio was larger than or in the same range as that of the two comparing methods.
46.	Alrammahi, Faris S., et al. (författare) Earthen slope stability using dimensional analysis 2021. - 1 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 1895 Konferensbidrag (refereegranskat)abstract Slope stability is an important aspect in the management of civil engineering projects. The stability of earth slopes is a significant concern for safety and the economy. There are several methods for finding the safety factor. Spencer's method is considered one of the most accurate methods for calculating the factor of safety but it depends on the others on dividing the slope geometry into the number of slices with complicated calculations. This paper introduced a new theoretical equation (using dimensional analysis) capable of defining and testing the slope stability of the natural and man-made slope of the earth without complicated calculations. The major and significant variables which affect and contribute to the stability of a slope will be listed and discussed. The Geo-SLOPE and SEEP software were used to present the stability analyses of the earth dam and compare the result. The derived equation shows the excellent relationship between the factor of safety concerning the ratio of internal friction angle over slope angle ∅/α and the hydraulic gradient. The main objective is to set a new rapid method for checking the stability of slopes instead of a complex calculation that can describe the slope stability of the natural earth slope.
47.	Andersen, K. H., et al. (författare) A Proposal for a Next Generation European Neutron Source 2016 Ingår i: VI European Conference On Neutron Scattering (ECNS2015). - : IOP Publishing. ; 746:1 Konferensbidrag (refereegranskat)abstract We argue that it is not too early to begin the planning process for a next generation neutron source for Europe, even as the European Spallation Source is being constructed. We put forward three main arguments. Firstly, nowadays the period between the first scientific concept of a new facility being proposed and its actual realisation is approaching half a century. We show evidence for this. Secondly, there is a straightforward development of the short pulse/long pulse spallation concepts that will deliver gains in neutron brightness of more than a factor 30 over what the ESS will soon deliver and provide the optimum balance between resolution and intensity. We describe our concept, which is a spallation source where the proton pulse length is matched to the moderating time of slow neutrons. Thirdly, when we look at our colleagues in astronomy and high energy physics, we see that they have a totally different, more global and more ambitious approach to the coming generations of large facilities. We argue that it is time for the neutron community not simply to rest upon its laurels and take what is given but to be proactive..
48.	Astromskas, Gvidas, et al. (författare) Heterogeneous integration of InAs on W/GaAs by MOVPE 2008 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 100, s. 042043-042043 Konferensbidrag (refereegranskat)abstract InAs has been grown on W-GaAs patterned substrates using MOVPE. The selectivity of the growth and the nucleation process has been studied as a function of the temperature and the V/III-ratio in the MOVPE reactor. It is shown that the W guides the nucleation of the InAs on the GaAs and that the islands formed may be used to embed metal features in a hybride InAs/GaAs structure in agreement with previous overgrowth studies of W-InAs and W-GaAs. The electrical properties has also been evaluated demonstrating a reduction of resistance by a factor 5 for a hybride structure with an embedded grating as compared to an InAs/GaAs reference sample.
49.	Barillot, T., et al. (författare) Attosecond time delays in C-60 valence photoemissions at the giant plasmon 2015 Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6596 .- 1742-6588. ; 635, s. 112074-112074 Konferensbidrag (refereegranskat)abstract We perform time-dependent local density functional calculations of the time delay in C-60 HOMO and HOMO-1 photoionization at giant plasmon energies. A semiclassical model is used to develop further insights.
50.	Barreiro, D., et al. (författare) Deepening into the nucleation and fission processes of nano-hydrated ammonia clusters - A combined theoretical and experimental study 2020. - 20 Ingår i: Clusters / Nanosystems / Surfaces / Solids. - : IOP Publishing. - 1742-6588. ; 1412 Konferensbidrag (refereegranskat)abstract While largely studied in the macroscopic scale, the dynamics leading to the nucleation and fission of atmospheric aerosols are very poorly understood at the nano or molecular scale. A model system consisting on ionized hydrogen-bonded ammonia and water molecules have been studied experimentally using mass- and 3D momentum spectroscopy and theoretically using ab initio molecular dynamics simulations.

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