We use the CAMELS dataset to compare two different approaches in multi-step ahead forecasting of monthly streamflow. The first approach uses past monthly streamflow information only, while the second approach additionally uses past information about monthly precipitation and/or temperature (exogenous information). The incorporation of exogenous information is made by utilizing Prophet, a model largely implemented in Facebook. The findings suggest that the compared approaches are equally useful.

The aim of this work is to investigate the stochastic nature and time evolution of the solar radiation process for daily and hourly scale, with the ultimate goal of creating a new cyclostationary stochastic model capable of reproducing the dependence structure and the marginal distribution of hourly solar radiation via the clearness index K_T.

Electricity produced by gas instead of coal is more climate-friendly as it emits 2 times less CO₂ but with methane leakage rates > 3 % of production this advantage is lost. Ethane in (shale)gas can be used to identify gas leakage. The ratio of ethane/methane for European shale gas plays is derived and emission under different production and leakage scenarios is quantified. This can be used to design an atmospheric monitoring system that alerts competent authorities if unacceptable leakage occurs.

The cement industry involves high-energy consumption that generates high CO₂ emissions into the atmosphere. Environmental concerns can be addressed by replacing parts of Portland cement clinkers with pozzolanic materials in mortars and concrete. Slag, fly ash and silica fume are materials considered for the planned replacement. Research studies on clay minerals, such as kaolinite, are being followed with special attention by the scientific community and the cement industry.

This study shows that global implementation of a circular system to treat waste and wastewater could increase the relative contribution of these sources to global energy demand from 2 % to 9 % by 2040, corresponding to a maximum energy potential of 64 EJ per year. The outcome of the study is the result of compiling and analyzing data on waste and wastewater generation and treatment and developing future scenarios in which carbon flows and energy generation are quantified for 174 country-regions.

The study discusses the fundamental criticism of a techno-economic oriented and target-deterministic energy planning by GIS. Proceeding from this, more complex approaches to the integration of social perspectives into GIS-planning tools are exemplified. The essential innovation integrated into the GIS-tool is the potential to quickly change economic, ecological and social parameters; thus, maps of the spatial dynamics of renewable energy site planning can easily be calculated.

Macerals are the constituents of coal and usually have a small size (e.g. micro-scaled). Therefore, we used nanoindentation to determine material parameters like hardness and reduced elastic modulus from macerals in well examined coals from the Ukrainian Donets Basin. Our main goal was to study the relationship of these parameters with increasing rank of coal. The results indicate that multiple factors control the mechanical properties of macerals (e.g. microstructure, depositional environment).

Aquifer Thermal Energy Storage Systems (ATES) save energy for heating and cooling. They are often placed in aquifers in which salinity increases with depth (in coastal areas where urbanization is high). The seasonally alternating extraction and re-injection between ATES wells disturbs the preexisting ambient salinity gradient which trigger buoyancy flow, which in turn affects the recovery efficiency of these systems. This paper shows under which condtions this is a threat for ATES systems.

Silicon carbide is seen as a possible replacement for metals as canister material in geological disposal of radioactive waste. The performed calculations on a small model underline the concept that the SSiC canister alone sustains definite loading of the host rock, but should be protected generally by a mechanically robust over pack preferably made of carbon concrete to complete a final waste package for all types of host rocks (shared and split functionality in TRIPLE C concept).

The main concern of UPSH using abandoned mines is the water exchanges between the underground reservoir and the surrounding medium, which are relevant in terms of environmental impact and the system efficiency. This work is based in real abandoned slate mine and investigates how the geometry of the mine affects the groundwater exchanges and their associated consequences.

The combination of high resolution Digital Color Images, Terrestrial Laser Scanner and Digital Photogrammetry survey is presented. Starting from this 3-D model an Acoustic Tomography was planned and carried out using geophysical and petrographical data sets. The different nature of the 3-D data volume provides a less ambiguous image of the materials and contributes in efficiency by increasing both fidelity and resolution in the non-destructive diagnostic process of architectural structures.

Underground pumped storage hydropower (UPSH) induces hydrochemical changes that may impact the environment and the efficiency of the system, especially if pyrite is present. This works assess the role of the hydraulic conductivity and the porosity on the system behavior by means of coupled hydro-chemical numerical models. This is helpful for selecting the most adequate abandoned mines for constructing UPSH plants.

Empirical models for growth of renewable power are compared; the exponential, logistic, and power-law models. It is shown that the latter is a natural model for growth that slows down due to various constraints, yet not experiencing the effect of an upper limit defined by physical boundaries. One cannot conclude that this model is preferable based on the historical data only, but the predictions also align well with scenarios based on macroeconomic modelling that meet the two-degree target.

A theoretical model of the Compression of the Damaged Zone experiment performed is proposed. One of the key features of the present model is its ability to yield the crack closure. The mechanical and hydric effects are examined seperately: in one case a prescribed pressure is applied at the drift wall, and swelling strains in the cracked zone are introduced in the other to model its resaturation. The intensity of the crack closure is heterogeneous in both cases but is greater in the latter.

In this survey, model samples were prepared according to an ancient lime–pozzolan mortar recipe with blood addition. Samples were studied by several analytical techniques. Results suggested that amorphous calcium carbonate could be formed in the specimens containing oxblood. This paper aims to allow an understanding of possible effects induced by organic additives on mortars and proposes a multi-discipline approach to bridge architectural history and building materials to conservation science.

In current applications of short term wind power forecasts, reliability information for the forecast is important because it helps decision making. Forecast errors are often estimated using ensembles of slightly disturbed weather predictions. Since this is very computation intensive, we propose a new method: A Deep Neural Network learns how reliable to forecast is, by comparing the current weather forecast with historical forecasts and the corresponding wind power production.

Froth flotation is being tested in Gonçalo pegmatites to produce a lepidolite concentrate. The flotation rejects are mainly composed by a mixture of feldspar, quartz and non-recovered lepidolite (very low content). The scenario could be improved by applying froth flotation also for feldspar/quartz separation: the feldspar concentrate can be used to produce sanitary ware and tiles and quartz for glass and silica flour, reaching an almost zero waste production.

Between 2004 and 2017 the storage of CO₂ in a deep saline aquifer was investigated in detail at the Ketzin pilot site close to Berlin. Th research projects incorporated an interdisciplinary scientific monitoring program during all phases of the storage process which provided a reliable insight into the overall behaviour of CO₂ during storage in the underground. During the drilling operation continuous mud gas logging was performed for continuous separation and analyses of the extracted gas.