Laboratory and on-site tests for rapid runway repair

The attention to rapid pavement repair has grown fast in recent decades: this topic is strategic for the airport management process for civil purposes and peacekeeping missions. This work presents the results of laboratory and on-site tests for rapid runway repair, in order to analyse and compare technical and mechanical performances of 12 different materials currently used in airport. The study focuses on site repairs, a technique adopted most frequently than repairs with modular elements. After describing mechanical and physical properties of the examined materials (2 bituminous emulsions, 5 cement mortars, 4 cold bituminous mixtures and 1 expanding resin), the study presents the results of carried out mechanical tests. The results demonstrate that the best performing material is a one-component fast setting and hardening cement mortar with graded aggregates. This material allows the runway reopening 6 h after the work. A cold bituminous mixture (bicomponent premixed cold asphalt with water as catalyst) and the ordinary cement concrete allow the reopening to traffic after 18 h, but both ensure a lower service life (1000 coverages) than the cement mortar (10,000 coverages). The obtained results include important information both laboratory level and field, and they could be used by airport management bodies and road agencies when scheduling and evaluating pavement repairs

Szenarien einer nachhaltigen Kraftwerksentwicklung in Deutschland

Die deutsche Bundesregierung hat sich das Ziel gesetzt, die Treibhausgasemissionen bis zum Jahr 2020 um 40 Prozent gegenüber 1990 zu senken. Aktuelle Projektionen gehen davon aus, dass dieses Ziel ohne weitere Klimaschutz-Maßnahmen nicht erreicht wird. Im Jahr 2020 muss voraussichtlich eine zusätzliche Menge von etwa 70 Millionen Tonnen CO2 reduziert werden. Dazu muss der Stromsektor - neben anderen Sektoren wie der Industrie, dem Verkehr, dem Handel oder den privaten Haushalten - einen relevanten Beitrag leisten. Derzeit entstehen etwa 85 Prozent der strombedingten Emissionen in Braun- und Steinkohlekraftwerken. Bestehende Kohlekraftwerke weisen eine hohe CO2-Intensität sowie eine geringe Flexibilität der Stromerzeugung auf. Über die Hälfte der deutschen Steinkohlekapazitäten sind älter als 30 Jahre, auch viele Braunkohleblöcke sind sehr alt. Langfristig haben diese Kraftwerke keinen Platz mehr in einem kohlenstoffarmen, auf erneuerbaren Energien basierten Stromsystem. Das Ziel, die jährlichen Treibhausgasemissionen in Deutschland bis zum Jahr 2020 um 40 Prozent zu reduzieren, droht verfehlt zu werden. Im Rahmen des derzeit von der Bundesregierung vorbereiteten Aktionsprogramms Klimaschutz 2020 wird daher eine frühzeitige Stilllegung von Kohlekraftwerken diskutiert. Die Gelegenheit hierfür erscheint aufgrund der derzeit bestehen Überkapazitäten bei der Stromerzeugung in Deutschland und den damit einhergehenden niedrigen Großhandelspreisen sowie hohen Stromexporten günstig. In der Studie wurden anhand eines detaillierten Modells des deutschen Strommarktes die Auswirkungen unterschiedlicher Szenarien der Schließung von Kohlekraftwerken ermittelt. Den Szenariorechnungen zufolge könnten im kommenden Jahr rund 23 Millionen Tonnen Kohlenstoffdioxid weniger ausgestoßen werden, wenn Steinkohlekraftwerke mit einer Kapazität von drei Gigawatt und Braunkohlekraftwerke mit einer Kapazität von sechs Gigawatt vom Netz genommen würden; dies entspricht immerhin einem Drittel der Stromlücke. Ein stärkerer Rückgang der Braunkohleverstromung (-40 TWh) stünde eine Zunahme der Erdgasverstromung (+ 26 TWh) gegenüber; auch die Steinkohleverstromung würde leicht zunehmen (+13 TWh); mit steigendem Börsenstrompreis sinkt die EEG-Umlage, sodass die Endkundenpreise nicht notwendigerweise steigen müssen. Die Studie zeigt, dass die Stilllegung alter und ineffizienter Kohlekraftwerke das Erreichen der Klimaschutzziele in Deutschland erleichtert. Gleichzeitig kann die verbesserte Marktsituation kostspielige und möglicherweise sehr CO2-intensive Kapazitätsmechanismen ersparen

Analisis Struktur Perkerasan Multi-Layer Menggunakan Program Komputer ELMOD Studi Kasus: Jalan Tol Jakarta - Cikampek

. An analytical method of overlay design has some advantages such as to take into account the variation of loading types which will give more exact and accurate results. The purpose of this research is to analyze the pavement structure of Jakarta-Cikampek toll road,for analysis period between 1990-1999 and to calculate the residual life and overlay thickness required, based on the deflection data using FWD equipment and analyzed by ELMOD computer program.The results then were compared with the empirical method i.e. Bina Marga method. The result of Bina Marga method show that for Jakarta-Cikampek direction there were eight critical points which have residual life less than one year and 7,0 cm overlay thickness required. For Cikampek-Jakarta direction, there was no critical point, their residual life was more than 10 years, and overlay thickness required is 3,0 cm. The ELMOD program gives the result for Jakarta-Cikampek direction that there are two critical points which have zero residual life and one critical point which has residual life less than one year, the overlay thickness required was 7,2 cm. For Cikampek-Jakarta direction, there was no critical point, the residual life was more than 20 years and no overlay required

Electricity sector data for policy-relevant modeling: Data documentation and applications to the German and European electricity markets

[Summary] The dataset for the European electricity system needs a variety of data to cover the relevant characteristics of the industry. The more general data on aggregated generation capacities, historic generation, and consumption can be found with a consistent data specification for most European countries in databases like EUROSTAT. On the other hand, more detailed data like generation capacities for conventional and renewable sources are usually not publicly available, sometimes not even on a national basis, and henceforth appropriate assumptions or commercial databases are required to retrieve the necessary information. Due to the already mentioned issue with regard to available information, setting up a consistent dataset for the European electricity system is more difficult in comparison to the German electricity system, where mostly consistent data is publicly available. Similar projects on a European level could be helpful for a consistent dataset. Having set up a dataset for Europe, the model application shows that the general tendencies on regional generation and import/export pattern can be captured. However, differences are obvious in particular regions where the model shows different results than the historic values which may be based either on the rough modeling approach or on an insufficient data supply. To that end, the presented dataset and model application are a continuous process, and further steps are required to improve the data quality as well as the modeling. Among others, the implementation of cogeneration restrictions, improvement of renewable generation and their distribution, and an intertemporal model calibration are potential improvements for the future

Analysing the interactions between Variable Renewable Energies, electricity storage and grid in long term energy modelling tools

International audienceEnergy systems are changing worldwide: new energy policies promote more sustainable energy productions, including Variable Renewable Energy sources (VREs) such as wind or solar. The long-term implications of the variability and relative unpredictability of these non dispatchable energy sources need to be assessed, for example with energy scenarios. Indeed, electricity is not a homogeneous good: its value depends on the time, space and how variable a production is. Long-term energy models are used, VREs integration challenges being a hot topic in energy modelling. An assessment of long-term energy models is necessary to understand how they represent the specific constraints of VREs on the rest of the power system. Therefore a new typology is proposed for comparing both long-term energy models and power sector models. This comparison shows that – despite all the recent modelling efforts – no long-term energy model represents in detail all the impacts of VREs on the power sector. For example, the sequential representation of the electricity storage operation is too precise for many long-term models. Therefore we develop a dedicated new power sector module, EUCAD (European Unit Commitment And Dispatch). The particularity of the work is that it is connected to POLES (Prospective Outlook on Long-term Energy Systems), one of the most technology-detailed long-term energy models. We present the first results of this new detailed electricity module

Analysing the interactions between Variable Renewable Energies, electricity storage and grid in long term energy modelling tools

International audienceEnergy systems are changing worldwide: new energy policies promote more sustainable energy productions, including Variable Renewable Energy sources (VREs) such as wind or solar. The long-term implications of the variability and relative unpredictability of these non dispatchable energy sources need to be assessed, for example with energy scenarios. Indeed, electricity is not a homogeneous good: its value depends on the time, space and how variable a production is. Long-term energy models are used, VREs integration challenges being a hot topic in energy modelling. An assessment of long-term energy models is necessary to understand how they represent the specific constraints of VREs on the rest of the power system. Therefore a new typology is proposed for comparing both long-term energy models and power sector models. This comparison shows that – despite all the recent modelling efforts – no long-term energy model represents in detail all the impacts of VREs on the power sector. For example, the sequential representation of the electricity storage operation is too precise for many long-term models. Therefore we develop a dedicated new power sector module, EUCAD (European Unit Commitment And Dispatch). The particularity of the work is that it is connected to POLES (Prospective Outlook on Long-term Energy Systems), one of the most technology-detailed long-term energy models. We present the first results of this new detailed electricity module

Investigations of dust in the upper atmosphere by optical radar Final report, 1 Jul. 1966 - 31 Jul. 1968

Upper atmospheric dust investigations using optical radar technique

A spatial electricity market model for the power system of Kazakhstan

Kazakhstan envisions a transition towards a green economy in the next decades which poses an immense challenge as the country heavily depends on (hydro-)carbon resources, for both its economy and its energy system. In this context, there is a lack of comprehensive and transparent planning tools to assess possible sustainable development pathways in regard to their technical, economic, and environmental implications. We present such a tool with a comprehensive techno-economic model of the Kazakh electricity system which determines the hourly least-cost generation dispatch based on publicly available data on the technical and economic characteristics of power plants and the transmission infrastructure. This modeling framework accounts for the particularities of the Kazakh electricity system: i) it has a detailed representation of combined heat and power, and ii) line losses are endogenously determined using a linear approximation. Model results are examined for a typical winter week (with annual peak load) and a typical summer week (with the hour of lowest annual load) presenting regionally and temporally disaggregated results for power generation, line utilization, and nodal prices. In an application to market design, the paper compares nodal and zonal pricing as two possible pricing schemes in Kazakhstan for the envisioned strengthening of the day-ahead market. In general, the model can be readily used to analyze the least-cost dispatch of the current Kazakh electricity system and can be easily expanded to assess the sector's development. Among others, possible applications include investment in transmission lines and in the aging power plant fleet, scenarios and policy assessment for emission reduction, and questions of market liberalization and market design

Illustrating the Benefits of Openness: A Large-Scale Spatial Economic Dispatch Model Using the Julia Language

In this paper we introduce a five-fold approach to open science comprised of open data, open-source software (that is, programming and modeling tools, model code, and numerical solvers), as well as open-access dissemination. The advantages of open energy models are being discussed. A fully open-source bottom-up electricity sector model with high spatial resolution using the Julia programming environment is then being developed, describing source code and a data set for Germany. This large-scale model of the electricity market includes both generation dispatch from thermal and renewable sources in the spot market as well as the physical transmission network, minimizing total system costs in a linear approach. It calculates the economic dispatch on an hourly basis for a full year, taking into account demand, infeed from renewables, storage, and exchanges with neighboring countries. Following the open approach, the model code and used data set are fully publicly accessible and we use open-source solvers like ECOS and CLP. The model is then being benchmarked regarding runtime of building and solving against a representation in GAMS as a commercial algebraic modeling language and against Gurobi, CPLEX, and Mosek as commercial solvers. With this paper we demonstrate in a proof-of-concept the power and abilities, as well as the beauty of open-source modeling systems. This openness has the potential to increase the transparency of policy advice and to empower stakeholders with fewer financial possibilities.BMWi, 03ET4028A, Verbundvorhaben: Langfristige Planung und kurzfristige Optimierung des Elektrizitätssystems in Deutschland im europäischen Kontext, Teilvorhaben: Langfristige Planung des Übertragungsnetzes in Deutschland unter Berücksichtigung der Interpendenzen zur Erzeugungsplanung, sowie zum Wärme- und Gassektor