The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods to examine these parameters were developed, validated and applied in three patients of a family which underwent an ambulatory course of COVID-19 for six months. The virus load had almost completely disappeared after about four weeks. Serum IgA levels to the S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau at approximately six weeks, and stayed elevated over the observation period. Virus-neutralizing activity reached a peak about 4 weeks after disease onset but dropped slowly. The longitudinal associations of virus neutralization and the serological immune response suggest immunity in patients even after a mild clinical course of COVID-19.
Summary Background Patients infected with SARS-CoV-2 exhibit a highly variable clinical course, varying from barely discernible signs of disease, to moderate flu-like symptoms and, occasionally, with life-threatening pneumonia and/or cytokine storm. The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein as well the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients has not been investigated longitudinally so far. Methods Several new serological methods to examine these parameters were developed and validated for the longitudinal investigation in three patients of a family which underwent a mild course of COVID-19. Findings We observed that the virus load had almost completely disappeared after about four weeks, whereas serum antibodies showed a contrasting course. IgA levels to S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau approximately six weeks after disease onset. NAbs in serum reached a peak about four weeks after disease onset but dropped to a lower level about six weeks later. Interpretation Our data establishes associations of virus neutralization and a serological immune response foremost against Sars-CoV-2 S1-RDB-protein in a longitudinal manner.
PERCIVAL (“Pixelated Energy Resolving CMOS Imager, Versatile And Large”) is a monolithic active pixel sensor (MAPS) based on CMOS technology. Is being developed by DESY, RAL/STFC, Elettra, DLS, and PAL to address the various requirements of detectors at synchrotron radiation sources and Free Electron Lasers (FELs) in the soft X-ray regime. These requirements include high frame rates and FELs base-rate compatibility, large dynamic range, single-photon counting capability with low probability of false positives, high quantum efficiency (QE), and (multi-)megapixel arrangements with good spatial resolution. Small-scale back-side-illuminated (BSI) prototype systems are undergoing detailed testing with X-rays and optical photons, in preparation of submission of a larger sensor. A first BSI processed prototype was tested in 2014 and a preliminary result—first detection of 350eV photons with some pixel types of PERCIVAL—reported at this meeting a year ago. Subsequent more detailed analysis revealed a very low QE and pointed to contamination as a possible cause. In the past year, BSI-processed chips on two more wafers were tested and their response to soft X-ray evaluated. We report here the improved charge collection efficiency (CCE) of different PERCIVAL pixel types for 400eV soft X-rays together with Airy patterns, response to a flat field, and noise performance for such a newly BSI-processed prototype sensor.
Our goal is to provide the scientific community with a large (10cm × 10cm) pixellated detector featuring a large dynamic range (1-105 photons), good spatial resolution (27μm), good Quantum Efficiency (QE) in the low energy range (250eV-1keV), variable readout speed (up to 120 frames/s), i.e. with characteristics compatible with user needs at today's of low-energy Free Electron Lasers (FEL) and synchrotron sources.
The Percival Collaboration is developing a high-speed,low X-ray energy detector capable of detecting single pho-tons while maintaining a large dynamic range of sensitivity.The increased brilliance of state-of-the-art Synchrotronradiation sources and Free Electron Lasers require imagingdetectors capable of taking advantage of these light sourcefacilities. The PERCIVAL ("Pixelated Energy ResolvingCMOS Imager, Versatile and Large") detector is being de-veloped in collaboration between DESY, Elettra SincrotroneTrieste, Diamond Light Source and Pohang Accelerator Lab-oratory.It is a CMOS detector targeting soft X-rays < 1 KeV, witha high resolution of up to 13 M pixels reading out at 120 Hz,producing a challenging data rate of 6 GiB/s.The controls and data acquisition system will include aSoftware Development Kit to allow integration with thirdparty control systems like Tango and DOOCS; an EPICS [1]areaDetector [2] driver will be included by default. It willmake use of parallel readout to keep pace with the datarate, distributing the data over multiple nodes to create asingle virtual dataset using the HDF5 file format for its speedadvantages in high volumes of regular data.This development project will culminate in a control andDAQ system capable of dealing with very high data rateswhile providing easy integration with site-specific controlsystems.This report presents the design of the control system soft-ware for the Percival detector, an update of the current stateof the implementation carried out by Diamond Light Source.
Considerable interest has been manifested for the use of high-brilliance X-ray synchrotron sources and X-ray Free-Electron Lasers for the investigation of samples.
The PERCIVAL ("Pixelated Energy Resolving CMOS Imager, Versatile and Large") is a collaboration of DESY, RAL/STFC, ELETTRA, and DLS to develop a monolithic active pixel sensor (MAPS) to provide a suitable detector for photon science for the photon energy regime between 250 eV and 1 keV. An important performance parameter is the spatial resolution which can be inferred from the Modulation Transfer Function (MTF). The MTF measures in optical systems the relative contrast of a pattern in function of the spatial frequency. With a back-thinned and back- illuminated PERCIVAL prototype chip, dedicated MTF evaluation data were taken at Elettra's TwinMic Beamline in March 2014 at a photon energy of 535 eV. We will present our MTF derivation approaches together with MTF results for 3 pixel types of the irradiated test sensor.
Thermal conductivity of the ground is generally measured in field by TRT (thermal response test) without considering non-uniformity and the groundwater flow. However, both factors can affect the performance of BHE (borehole heat exchangers) drastically. Hence, analysis of thermal conductivity in layered subsurface with taking into account groundwater flow and its effect on performance of BHE is necessary.
Der Eigendrehimpuls von Elektronen in Halbleiter-Hybridstrukturen ist das zentrale Thema des ersten deutsch-russischen Sonderforschungsbereichs. Sein Sprecher, der Dortmunder Physiker Manfred Bayer, stellt den Verbund vor, gepaart mit personlichen Eindrucken.
The PERCIVAL soft-X-ray (250 eV 1 keV) image detector project is a collaboration between DESY, STFC, Elettra Sincrotrone Trieste and Diamond Light Source. The objective of the project is to develop a back-thinned CMOS detector which outperforms present soft-X ray image detector technology, in terms of sensor size, noise, dynamic range and frame rate. The size of this 13M pixel imager associated with its 120 frames per second frame rate impose very challenging requirements to the Data Acquisition Backend of the system. A DAQ backend system architecture, using a commercial deep-buffer switch to rearrange image data streams coming from different regions of the sensor via several 10Gbps Ethernet links has been proposed to reassemble image frames. Real-time data processing is to be performed on multiple, parallel commodity compute nodes. This contribution to the conference reports on benchmarking tests performed as a feasibility study, and presents the resulting recommendations for the system architecture of the PERCIVAL detector DAQ backend. The feasibility study covered three key issues: Reliably moving data in UDP packets from multiple 10Gbps Ethernet links from the DAQ front-end electronics to commodity compute nodes; Real-time processing on the compute nodes; and finally streaming data to a central parallel storage system.
This paper examines thermal performance of a ground source heat pump (GSHP) system. The GSHP system was installed in an office building in Nuremberg city of Germany. In order to evaluate system performance the GSHP system has been continuously monitored for 4 years. Heating and cooling performance of the GSHP system is analyzed based on the accumulated data.Major findings of this work include: (1) coefficient of performance (COP) is estimated to be 3.9 for a typical winter day and energy efficiency ratio (EER) is assessed to be 8.0 for a typical summer day. These results indicate that the GSHP system has a higher efficiency for building cooling than building heating. (2) For a long-term period, the seasonal energy efficiency ratio (SEER) of the GSHP system is observed to increase by 8.7% annually, whereas the seasonal COP is decreased by 4.0% over a 4-year period. The heating and cooling performance of the GSHP system migrates in opposite trend is caused by the unevenly distributed heating and cooling load of the building. This phenomenon deserves serious attention in the design of future GSHP systems in order to avoid the reducing of energy efficiency over long-term operation. (C) 2014 Elsevier Ltd. All rights reserved.
In the current design of borehole heat exchangers (BHEs), the ground is commonly considered to be homogenous. However, in a layered subsurface, thermal performance of BHE can deviate drastically with different strata. Thereby, analysis of the heat transfer of a BHE with different geological layers is important for optimal sizing of BHE.In this paper, we examine thermal performance of BHEs settled in a ground with five bedded sedimentary layers. Thermal and hydraulic properties of the borehole field are firstly investigated. Based on the experimental data, a numerical model is developed to examine thermal exchange of the BHEs in this layered subsurface. Two modeling approaches, where the ground properties considered to be homogenous or stratified, are implemented. Numerical results from both approaches are validated and they give similar thermal output of the BHEs. The model with a stratified subsurface further indicates that there is only 74.1% amount of heat transferred in the basal layer with negligible groundwater flow as compared to that of aquifer layers. (C) 2014 Elsevier Ltd. All rights reserved.
Free-Electron Lasers and Synchrotrons are rapidly increasing in brilliance. This has led a requirement of large dynamic range and high frame rate sensors that is now being fulfilled by the PERCVIAL CMOS imager for direct X-ray detection developed at Rutherford Appleton Laboratory. Utilising a lateral overflow pixel and back-side illumination, PERCIVAL simultaneously achieves low-noise single-photon detection and high full well up to 10(7) e(-), all while maintaining a frame rate of 120Hz. PERCIVAL is currently in test structure stage, and will be produced in 2 Mpixel and 13 Mpixel "waferscale" variants in 2015.
Over the last decade, synchrotron radiation sources have seen a significant increase in brilliance, and the advent of free electron lasers has made entire new research fields accessible to investigations with X-rays. These advances in light source capabilities have resulted not only in a host of scientific advances and discoveries, but also in a need for a new generation of X-ray imaging detectors that can match the sources' capabilities in terms of frame rate and image dynamic range while recording image information with fine granularity over a large – preferably uninterrupted – (multi)megapixel area with single-photon sensitivity. Developing such next-generation imagers is both costly and time-consuming, and the requirements at many photon science facilities are similar enough to invite a collaborative effort. The Percival (“Pixellated Energy Resolving CMOS Imager, Versatile And Large”) imager is being developed by a collaboration of DESY, Rutherford Appleton Laboratory (RAL), Elettra, and Diamond Light Source (DLS) to answer this need for the soft X-ray regime.
•We investigate thermal load of borehole heat exchangers with three borehole diameters.•Increasing borehole diameter will slightly improve thermal performance of BHE.•Increasing borehole diameter will decrease the economic profitability.•Acceptable investments for a BHE with a larger diameter depend heavily on drilling cost.
In a vertical ground source heat pump (GSHP) system, horizontal pipe is the connection between borehole heat exchanger (BHE) and building. In current estimation of system performance, the energy loss of fluid circulating through a horizontal connecting pipe is often ignored. However, such energy loss can seriously reduce the thermal efficiency of GSHP systems in cold regions. This paper investigates the impacts of pipe burial depth and pipe insulation on energy loss of horizontal connecting pipes of a GSHP system in Nuremberg, Germany. The fluid circulation in a horizontal connecting pipe is investigated via experimental measurement and numerical simulation. Both the on-site data and numerical results suggest that the fluid temperature is substantially influenced by pipe burial depth as well as insulation. The numerical modeling shows that the daily energy loss can vary in magnitudes, as determined by pipe burial depth. On the other hand, up to 50% energy loss can be avoided by adopting a 25 mm thick insulation. These findings suggest that the both pipe burial depth and pipe insulation are important factors to be seriously considered for energy saving in the design and implementation of GSHP systems. (C) 2013 Elsevier Ltd. All rights reserved.
Thermal efficiency of borehole heat exchangers (BHE) is of crucial importance for the design and optimization of ground source heat pump (GSHP) system. This paper investigates thermal efficiency of a BHE with three drillhole diameters: 121 mm, 165 mm and 180 mm. The BHE was installed in a GSHP system of an office building located in Nuremberg, Germany. Thermal properties and hydraulic properties of the ground where the BHE was installed have been measured by thermal response tests as well as pumping tests. Furthermore, the evaluation of thermal performance is made possible by monitoring operation of the GSHP system. Using the recorded data, thermal exchange rates have been calculated and compared in a daily period as well as a seasonal period. The daily statistics indicate that the thermal exchange rate of the BHE increases with larger drillhole diameter. For the seasonal cooling performance, the amount of thermal exchange of BHE with 165 mm and 180 mm diameters was found to be 3.2% and 7.1% larger than that of the BHE with 121 mm diameter, respectively. These findings provide helpful suggestions for the design of future GSHP systems to achieve higher energy-efficiency.
This paper addresses the feasibility of higher education in relation to the demands of work life. The research is a comparative study involving four European countries: Sweden, Norway, Poland, and Germany. The research focuses on the view of freshmen, senior students and later graduates in Psychology and Political Science. Data were obtained by semi‐structured interviews, which were subjected to qualitative analyses. The results indicate that higher education, with some exceptions, seems to produce a discipline‐based identity among the students. These findings may be indicative of the value for employability of classical academic generic skills.
Electron spin coherence in self-assembled (In,Ga)As/GaAs quantum dots has been studied by pump-probe Faraday rotation experiments. Several aspects such as creation of spin coherence, spin dephasind, interaction with lattic nuclei will be discussed.