28 research outputs found
Dynamic provisioning of a HEP computing infrastructure on a shared hybrid HPC system
Experiments in high-energy physics (HEP) rely on elaborate hardware, software and computing systems to sustain the high data rates necessary to study rare physics processes. The Institut fr Experimentelle Kernphysik (EKP) at KIT is a member of the CMS and Belle II experiments, located at the LHC and the Super-KEKB accelerators, respectively. These detectors share the requirement, that enormous amounts of measurement data must be processed and analyzed and a comparable amount of simulated events is required to compare experimental results with theoretical predictions. Classical HEP computing centers are dedicated sites which support multiple experiments and have the required software pre-installed. Nowadays, funding agencies encourage research groups to participate in shared HPC cluster models, where scientist from different domains use the same hardware to increase synergies. This shared usage proves to be challenging for HEP groups, due to their specialized software setup which includes a custom OS (often Scientific Linux), libraries and applications.
To overcome this hurdle, the EKP and data center team of the University of Freiburg have developed a system to enable the HEP use case on a shared HPC cluster. To achieve this, an OpenStack-based virtualization layer is installed on top of a bare-metal cluster. While other user groups can run their batch jobs via the Moab workload manager directly on bare-metal, HEP users can request virtual machines with a specialized machine image which contains a dedicated operating system and software stack. In contrast to similar installations, in this hybrid setup, no static partitioning of the cluster into a physical and virtualized segment is required. As a unique feature, the placement of the virtual machine on the cluster nodes is scheduled by Moab and the job lifetime is coupled to the lifetime of the virtual machine. This allows for a seamless integration with the jobs sent by other user groups and honors the fairshare policies of the cluster. The developed thin integration layer between OpenStack and Moab can be adapted to other batch servers and virtualization systems, making the concept also applicable for other cluster operators.
This contribution will report on the concept and implementation of an OpenStack-virtualized cluster used for HEP work ows. While the full cluster will be installed in spring 2016, a test-bed setup with 800 cores has been used to study the overall system performance and dedicated HEP jobs were run in a virtualized environment over many weeks. Furthermore, the dynamic integration of the virtualized worker nodes, depending on the workload at the institute\u27s computing system, will be described
Dynamic Virtualized Deployment of Particle Physics Environments on a High Performance Computing Cluster
The NEMO High Performance Computing Cluster at the University of Freiburg has
been made available to researchers of the ATLAS and CMS experiments. Users
access the cluster from external machines connected to the World-wide LHC
Computing Grid (WLCG). This paper describes how the full software environment
of the WLCG is provided in a virtual machine image. The interplay between the
schedulers for NEMO and for the external clusters is coordinated through the
ROCED service. A cloud computing infrastructure is deployed at NEMO to
orchestrate the simultaneous usage by bare metal and virtualized jobs. Through
the setup, resources are provided to users in a transparent, automatized, and
on-demand way. The performance of the virtualized environment has been
evaluated for particle physics applications
Occurrence and distribution of resistance to QoI fungicides in populations of Podosphaera fusca in south central Spain
Cucurbit powdery mildew caused by Podosphaera fusca limits crop production in Spain. Since its management is strongly dependent on chemicals, the rational design of control programmes requires a good understanding of the fungicide resistance phenomenon in field populations. Fifty single-spore isolates of P. fusca were tested for sensitivity to three quinone-outside inhibiting (QoI) fungicides: azoxystrobin, kresoxim-methyl and trifloxystrobin. Minimum inhibitory concentration (MIC) values for QoI-sensitive isolates were found to range from 0.25 to 10 μg ml−1 for azoxystrobin to 5–25 μg ml−1 for kresoxim-methyl, using a leaf disc-based bioassay. High levels of cross-resistance to QoI fungicides were found. Eleven isolates showed resistance to the three QoI fungicides tested with MIC and EC50 values >500 μg ml−1 resulting in RF values as high as >715 and >1000 for trifloxystrobin and azoxystrobin, respectively. A survey of P. fusca QoI resistance was carried out in different provinces located in the south central area of Spain during the cucurbit growing seasons in 2002, 2003 and 2004. Examination of a collection of 250 isolates for QoI resistance revealed that 32% were resistant to the three fungicides tested; the provinces of Ciudad Real, Córdoba and Murcia being the locations with the highest frequencies of resistance (44–74%). By contrast, no resistance was found in Badajoz, and relatively low frequencies were observed in Almería and Valencia (10–13%). Nearly 50% of resistant isolates were collected from melon plants. Based on these data, recommendations about the use of QoI fungicides for cucurbit powdery mildew management in the sampled areas are made.Estación Experimental “La Mayora” (CSIC), Algarrobo-Costa, E-29750 Málaga, Spain
Grupo de Microbiología y Patología Vegetal-Unidad Asociada a CSIC, Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, E-29071 Málaga, SpainPeer reviewe
Разработка расчетных методов определения характеристик индустриальных масел
В ходе работы проанализированы характеристики индустриального масла марки И-20А, с использованием метода множественного регрессионного анализа разработаны расчетные способы определения характеристик индустриального масла, сделан вывод о точности разработанных методов, определены наиболее точные методы.In the course of the work, the characteristics of I-20A industrial oil were analyzed, using the multiple regression analysis method, calculation methods for determining the characteristics of industrial oil were developed, a conclusion was made on the accuracy of the developed methods, and the most accurate methods were determined
Electric dipole moments and the search for new physics
Static electric dipole moments of nondegenerate systems probe mass scales for
physics beyond the Standard Model well beyond those reached directly at high
energy colliders. Discrimination between different physics models, however,
requires complementary searches in atomic-molecular-and-optical, nuclear and
particle physics. In this report, we discuss the current status and prospects
in the near future for a compelling suite of such experiments, along with
developments needed in the encompassing theoretical framework.Comment: Contribution to Snowmass 2021; updated with community edits and
endorsement
Data-driven approach to derive the QCD background of W production in association with jets at the ATLAS experiment
Summer Student Project Report on data-driven approach to derive the QCD background of W production in association with jets at the ATLAS experiment
Low-Frequency Electrochemical Impedance Spectroscopy as a Monitoring Tool for Yeast Growth in Industrial Brewing Processes
Today’s yeast total biomass and viability measurements during the brewing process are dependent on offline methods such as methylene blue or florescence dye-based staining, and/or the usage of flow cytometric measurements. Additionally, microscopic cell counting methods decelerate an easy and quick prediction of yeast viability. These processes are time consuming and result in a time-delayed response signal, which not only reduces the knowledge of the performance of the yeast itself, but also impacts the quality of the final product. Novel approaches in process monitoring during the aerobic and anaerobic fermentation of Saccharomyces cerevisiae are not only limited to classical pH, dO2 and off-gas analysis, but they also use different in situ and online sensors based on different physical principles to determine the biomass, product quality and cell death. Within this contribution, electrochemical impedance spectroscopy (EIS) was used to monitor the biomass produced in aerobic and anaerobic batch cultivation approaches, simulating the propagation and fermentation unit operation of industrial brewing processes. Increases in the double-layer capacitance (CDL), determined at frequencies below 1 kHz, were proportional to the increase of biomass in the batch, which was monitored in the online and inline mode. A good correlation of CDL with the cell density was found. In order to prove the robustness and flexibility of this novel method, different state-of-the-art biomass measurements (dry cell weight—DCW and optical density—OD) were performed for comparison. Because measurements in this frequency range are largely determined by the double-layer region between the electrode and media, rather minor interferences with process parameters (aeration and stirring) were to be expected. It is shown that impedance spectroscopy at low frequencies is not only a powerful tool for the monitoring of viable yeast cell concentrations during operation, but it is also perfectly suited to determining physiological states of the cells, and may facilitate biomass monitoring in the brewing and yeast-propagating industry drastically
Mixed conductors under light: On the way to solid oxide photo-electrochemical cells
The final publication is available via https://doi.org/10.1149/07207.0023ecst.Photo-electrochemical cells based on aqueous electrolytes have been heavily investigated for their potential to convert light into chemical energy. In contrast, very little is known on the possibility of transferring photon energy into chemical energy in high temperature solid state electrochemical cells. This is true despite the fact that solid electrolyte based systems can be operated very successfully as fuel and electrolysis cells (SOFCs/SOECs). Here, we report results on the interaction of mixed conducting oxides with light in cells using oxide ion conductors and operating at 350-500°C. One type of system contains a high temperature solar cell based on SrTiO3 and LaCrO3. It allows oxygen pumping and thus chemical energy storage under UV light. In another type of system UV light produces a time dependent voltage that includes two processes potentially also enabling energy storage: First, again a photovoltaic effect is present; second, the illuminated mixed conducting oxide changes its stoichiometry and thus leads to a battery type (Nernstian) voltage.Austrian Science Funds (FWF)Austrian Research Promotion Agency (FFG