Combination of Gibbs and Helmholtz Energy Equations of State in a Multiparameter Mixture Model Using the IAPWS Seawater Model as an Example

For carbon capture and storage (CCS) applications different sets of equations of state are used to describe the whole CCS-chain. While for the transport and pipeline sections highly accurate equations of state (EOS) explicit in the Helmholtz energy are used, properties under typical geological storage conditions are described by more simple, mostly cubic EOS, and brines are described by Gibbs energy models. Combining the transport and storage sections leads to inconsistent calculations. Since the used models are formulated in different independent variables (temperature and density versus temperature and pressure), mass and energy balances are challenging and equilibria in the injection region are difficult to model. To overcome these limitations, a predictive combination of the Gibbs energy-based IAPWS seawater model (IAPWS R13-08, 2008) with Helmholtz energy-based multi-parameter EOS is presented within this work. The Helmholtz energy model used in this work is based on the EOS-CG-2016 of Gernert and Span (J Chem Thermodyn 93:274–293, 10.1016/j.jct.2015.05.015, 2016). The results prove that a consistent combination of the two different models is possible. Furthermore, it is shown, that a more complex brine model needs to be combined with Helmholtz energy EOS for calculations at storage conditions.

Estimating Visible Band Albedo from Aerial Orthophotographs in Urban Areas

Albedo is an important parameter in many environmental and renewable energy models. Satellite sensors can be used to derive broadband or narrowband albedos. However, the spatial resolution of such data can be insufficient in urban areas with complex morphology and land cover diversity. In this study, we propose the use of widely available aerial orthophotographs to derive visible band albedo in urban surfaces that can be effectively used in high-resolution applications. The solution is based on the estimation of the reflected irradiance captured by an RGB sensor and approximated by the brightness component in the hue-saturation-brightness (HSB) color model and incident solar irradiance modelled by the r.sun module in GRASS GIS. The visible band albedo values are calibrated by published reference values for selected land cover classes or, alternatively, by a spectroradiometer. The method is applied to the central part of Košice and compared to visible band albedo derived from the Landsat 8 OLI and Sentinel 2A sensors and previously published typical albedo values for various land cover classes, resulting in reasonable agreement. The proposed methodology is implemented using standard GIS tools that are easily applicable to any high-resolution urban data.

A Short Review on Clustering Dark Energy

We review dark energy models that can present non-negligible fluctuations on scales smaller than Hubble radius. Both linear and nonlinear evolutions of dark energy fluctuations are discussed. The linear evolution has a well-established framework, based on linear perturbation theory in General Relativity, and is well studied and implemented in numerical codes. We highlight the main results from linear theory to explain how dark energy perturbations become important on the scales of interest for structure formation. Next, we review some attempts to understand the impact of clustering dark energy models in the nonlinear regime, usually based on generalizations of the Spherical Collapse Model. We critically discuss the proposed generalizations of the Spherical Collapse Model that can treat clustering dark energy models and their shortcomings. Proposed implementations of clustering dark energy models in halo mass functions are reviewed. We also discuss some recent numerical simulations capable of treating dark energy fluctuations. Finally, we summarize the observational predictions based on these models.

A new class of holographic dark energy models in LRS Bianchi Type-I

In this paper, we examine the LRS Bianchi-type-I cosmological model with holographic dark energy. The exact solutions to the corresponding field equations are obtained by using the generalized hybrid expansion law (HEL). The EoS parameter [Formula: see text] for DE is found to be time-dependent and redshift-dependent and its exiting range for derived model is agreeing well with the current observations. Here, we likewise apply two mathematical diagnostics, the statefinders ([Formula: see text]) and [Formula: see text] plan to segregate HDE model from the [Formula: see text]CDM model. Here, the [Formula: see text] diagnostic trajectories are good tools to classify the dynamical DE model. We found that our model lies in both thawing region and freezing region. We also construct the potential as well as dynamics of the quintessence and tachyon scalar field. Some physical and geometric properties of this model along with the physical acceptability of cosmological solution have been discussed in detail.

Neutron Stars in the Symmetron Model

Screening mechanisms are often deployed by dark energy models to conceal the effects of their new degrees of freedom from the scrutiny of terrestrial and solar system experiments. However, the extreme properties of nuclear matter may lead to a partial failure of screening mechanisms inside the most massive neutron stars observed in nature, opening up the possibility of probing these theories with neutron star observations. In this work, we explore equilibrium and stability properties of neutron stars in two variants of the symmetron model. We show that around sufficiently compact neutron stars, the symmetron is amplified with respect to its background (cosmological) value by several orders of magnitude, and that the properties of such unscreened stars are sensitive to corrections to the leading linear coupling between the symmetron and matter.

Architectural Models as a Base for Reliable Early Stage Energy Simulation

<p>Designers from the Architecture, Engineering, and Construction (AEC) industries have shown a desire to allow for quantitative data to back up sustainable decision-making (Braasch, 2016). Methods and software used to reach this goal often do not provide all the information to make informed design decisions or require a complete remodelling of designs at each stage. These factors make Building Performance Simulation (BPS) feasible at early design stages, where it is most beneficial for Architects. This thesis explores the current process to translate Architectural models constructed within a Building Information Modelling (BIM) environment into Building Energy Models (BEM) so that performance simulations can take place. Within the aim of exploring translation processes, the objectives were to document: • Whether current processes can facilitate modelling of environmental building performance during early design, as well as during developed design? • Whether there are any common problems or successful approaches that might form the basis of future improvements in the way Architect’s and consultant’s models work together? This thesis has identified 19 translation processes from current literature and examined a range of representative processes for exchanging information between Architectural modelling and BPS programs. It concluded that translation issues can be classified into similar groups based on the overall processes used. The eight categories of issues can be used by future developers to determine their priorities in development, and those looking for a current solution can adopt one for themselves. None of the processes tested allowed for issue-free modelling of building performance during sketch design. The two types of building translation schema evaluated in this thesis divided identified references between a dedicated and generalised approach. The dedicated approach of gbXML and the generic approach of IFC identified similar issues; however, IFC contained more of these problems because it communicates with all modelling programs at a lower information quality. Due to the generic approaches containing more issues that take longer to solve, it is currently more complicated to generate an energy model out of IFC data. While the gbXML schema can only provide benefits for BPS related translations, it is the most viable way to provide the service.</p>

Architectural Models as a Base for Reliable Early Stage Energy Simulation

<p>Designers from the Architecture, Engineering, and Construction (AEC) industries have shown a desire to allow for quantitative data to back up sustainable decision-making (Braasch, 2016). Methods and software used to reach this goal often do not provide all the information to make informed design decisions or require a complete remodelling of designs at each stage. These factors make Building Performance Simulation (BPS) feasible at early design stages, where it is most beneficial for Architects. This thesis explores the current process to translate Architectural models constructed within a Building Information Modelling (BIM) environment into Building Energy Models (BEM) so that performance simulations can take place. Within the aim of exploring translation processes, the objectives were to document: • Whether current processes can facilitate modelling of environmental building performance during early design, as well as during developed design? • Whether there are any common problems or successful approaches that might form the basis of future improvements in the way Architect’s and consultant’s models work together? This thesis has identified 19 translation processes from current literature and examined a range of representative processes for exchanging information between Architectural modelling and BPS programs. It concluded that translation issues can be classified into similar groups based on the overall processes used. The eight categories of issues can be used by future developers to determine their priorities in development, and those looking for a current solution can adopt one for themselves. None of the processes tested allowed for issue-free modelling of building performance during sketch design. The two types of building translation schema evaluated in this thesis divided identified references between a dedicated and generalised approach. The dedicated approach of gbXML and the generic approach of IFC identified similar issues; however, IFC contained more of these problems because it communicates with all modelling programs at a lower information quality. Due to the generic approaches containing more issues that take longer to solve, it is currently more complicated to generate an energy model out of IFC data. While the gbXML schema can only provide benefits for BPS related translations, it is the most viable way to provide the service.</p>