Wide Area Monitoring with Synchrophasor Measurements has become of great interest in supervision of stability for transmission systems. With the acquisition of the phasor measurements using Phasor ...Measurement Units (PMU), a new quality of insight into the dynamic behavior of the electric power network has become possible. The value of this method is increasing because of more dynamic requirements for the system caused by renewable power infeed such as wind and solar and energy trade. The renewable power infeed goes to a quite high amount into the distribution networks so that at that level, also the dynamic processes are increasing. The distribution networks are taking over more tasks that have been reserved for transmission networks in the past, so the supervision is also important for the distribution level. This paper discusses applications for that. An example for the use of synchrophasors for energy accounting is given. Finally, the status of standardization is presented.
The article presents a new concept for vascular endoprothesis (stent). Almost all commercially available stents are made of metallic materials. A common after effect of stent implantation is ...restenosis. Several studies on metal stents coated with drug show, that the use of a drug delivery system may reduce restenosis. The purpose of this work is to develop a new stent for the drug delivery application. The shape memory properties of thermoplastic polyurethane allow to design a new fully polymeric self-expandable stent. The possibility to use the stent as a drug delivery system is described.
Hydraulic fracturing (HF) operations are widely associated with induced seismicity in the Western Canadian Sedimentary Basin. This study correlates injection parameters of 12,903 HF stages in the ...Kiskatinaw area in northeast British Columbia with an enhanced catalog containing 40,046 earthquakes using a supervised machine learning approach. It identifies relevant combinations of geological and operational parameters related to individual HF stages in efforts to decipher fault activation mechanisms. Our results suggest that stages targeting specific geological units (here, the Lower Montney formation) are more likely to induce an earthquake. Additional parameters positively correlated with earthquake likelihood include target formation thickness, injection volume, and completion date. Furthermore, the COVID‐19 lockdown may have reduced the potential cumulative effect of HF operations. Our results demonstrate the value of machine learning approaches for implementation as guidance tools that help facilitate safe development of unconventional energy technologies.
Plain Language Summary
Hydraulic fracturing (HF), a technique used in unconventional energy production, increases rock permeability to enhance fluid movement. Its use has led to an unprecedented increase of associated earthquakes in the Western Canadian Sedimentary Basin in the last decade, among other regions. Numerous studies have investigated the relationship between induced earthquakes and HF operations, but the connection between specific geological and operational parameters and earthquake occurrence is only partly understood. Here, we use a supervised machine learning approach with publicly available injection data from the British Columbia Oil and Gas Commission to identify influential HF parameters for increasing the likelihood of a specific operation inducing an earthquake. We find that geological parameters, such as the target formation and its thickness, are most influential. A small number of operational parameters are also important, such as the injected fluid volume and the operation date. Our findings demonstrate an approach with the potential to develop tools to help enable the continued development of alternative energy technology. They also emphasize the need for public access to operational data to estimate and reduce the hazard and associated risk of induced seismicity.
Key Points
We use supervised machine learning to investigate the relationship between hydraulic fracturing operation parameters and induced seismicity
Geological properties and a limited number of operational parameters predominantly influence the probability of an induced earthquake
The approach has the potential to guide detailed investigations of injection parameters critical for inducing earthquakes
CORAL and COOL are two software packages used by the LHC experiments for managing detector conditions and other types of data using relational database technologies. They have been developed and ...maintained within the LCG Persistency Framework, a common project of the CERN IT department with ATLAS, CMS and LHCb. This presentation reports on the status of CORAL and COOL at the time of CHEP2013, covering the new features and enhancements in both packages, as well as the changes and improvements in the software process infrastructure. It also reviews the usage of the software in the experiments and the outlook for ongoing and future activities during the LHC long shutdown (LS1) and beyond.
The CORAL software is widely used at CERN by the LHC experiments to access the data they store on relational databases, such as Oracle. Two new components have recently been added to implement a ...model involving a middle tier "CORAL server" deployed close to the database and a tree of "CORAL server proxies", providing data caching and multiplexing, deployed close to the client. A first implementation of the two new components, released in the summer 2009, is now deployed in the ATLAS online system to read the data needed by the High Level Trigger, allowing the configuration of a farm of several thousand processes. This paper reviews the architecture of the software, its development status and its usage in ATLAS.
The LCG Persistency Framework consists of three software packages (CORAL, COOL and POOL) that address the data access requirements of the LHC experiments in several different areas. The project is ...the result of the collaboration between the CERN IT Department and the three experiments (ATLAS, CMS and LHCb) that are using some or all of the Persistency Framework components to access their data. POOL is a hybrid technology store for C++ objects, using a mixture of streaming and relational technologies to implement both object persistency and object metadata catalogs and collections. CORAL is an abstraction layer with an SQL-free API for accessing data stored using relational database technologies. COOL provides specific software components and tools for the handling of the time variation and versioning of the experiment conditions data. This presentation reports on the status and outlook in each of the three sub-projects at the time of the CHEP2012 conference, reviewing the usage of each package in the three LHC experiments.
The Persistency Framework consists of three software packages (CORAL, COOL and POOL) addressing the data access requirements of the LHC experiments in different areas. It is the result of the ...collaboration between the CERN IT Department and the three experiments (ATLAS, CMS and LHCb) that use this software to access their data. POOL is a hybrid technology store for C++ objects, metadata catalogs and collections. CORAL is a relational database abstraction layer with an SQL-free API. COOL provides specific software tools and components for the handling of conditions data. This paper reports on the status and outlook of the project and reviews in detail the usage of each package in the three experiments.
Abstract The NA48/2 experiment at CERN reports the first observation of the K ± → π 0 π 0 μ ± ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. ...The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV2/c 4 is measured to be (0.65 ± 0.03) × 10 −6. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10 −6, in agreement with chiral perturbation theory predictions.
The paper describes typical developments of blackouts from simple cause to cascading outages. Possible measures to increase the system observability, combined with power electronic equipments as ...controlling elements, can lead to a future closed loop control of the power supply. The possible increase of the overall network security by protection security assessment (PSA) and dynamic network security assessment (DSA) will be shown. The described network and protection simulations, which are available today for the transmission sector, have to be adopted to future distribution systems with dispersed generation.
This paper describes the principles and applications of Wide Area Monitoring with Synchrophasors from Phasor Measurement Units (PMU). The first part explains the reasons for the use of Wide Area ...Monitoring and the principle. The second part deals with applications on the central level (PDC, Phasor Data Concentrator). The last part presents aspects of the market status from a vendor's perspective and discusses some aspects of a R&D project in Germany. (4 pages)
PDF
