12 research outputs found
X-ray detector on 2U cubesat BeEagleSAT of QB50
BeEagleSAT is a 2 Unit cubesat to be launched within the EU FP7 project QB 50. It is been produced by Istanbul Technical University and Turkish Air Force Academy. Sabanci University will provide a CdZnTe based semiconductor X-ray detector and associated readout electronics. The detector will utilize cross strip geometry to test the detection system in space, but it will not carry a mask for imaging. The readout will be established by an application specific integrated circuit controlled by a microcontroller. The system will have its own battery and will be turned on intermittently due to power and telemetry constraints. It will characterize the hard X-ray background in 20-150 keV at low Earth orbit conditions as a function of altitude
Development and in orbit testing of an x ray detector within a 2U cubesat
A CdZnTe based semiconductor X-ray detector (XRD) and its associated readout electronics is developed by the Space Systems Design Laboratory of Istanbul Technical University and High Energy Astrophysics Detector Laboratory of Sabanci University along with an SME partner. The detector will utilize 30 orthogonal cross strip electrodes (and 3 steering electrodes in between anodes) whose geometry is optimized by an extensive set of simulations and energy resolution measurements. The signals will be read by RENA 3b ASIC controlled by MSP 430 microcontroller. The system will have its own battery and will be turned on intermittently due to power constraints. CdZnTe based X-ray detectors have been utilized in space, but they are either pixellated (NuStar), or they consist of many individual crystal pieces (BAT in Swift satellite). The aim of the XRD is to show that large volume crystals with orthogonal strips are viable alternatives, especially for small satellite systems with medium energy resolution requirement. XRD will also characterize the hard X-ray background in 20-200 keV at low Earth orbit conditions as a function of altitude. Due to power and telemetry constraints, the individual events will be corrected for hole trapping on-board, histogrammed, and only the X-ray spectra will be transmitted to the ground station along with a small set of raw data for diagnostic purposes.
The XRD is planned to travel into space, as a secondary science mission, on board BeEaglesat which is a 2U CubeSat developed as one of the possible double (2U) CubeSats for the QB50 project. QB50 is a European Framework 7 (FP7) project carried out by a number of international organizations led by the von Karman Institute of Belgium. Its main scientific objective is to study in situ the temporal and spatial variations of a number of key constituents and parameters in the lower thermosphere with a network of about 50 double and triple CubeSats, separated by few hundred kilometers and carrying a determined set of sensors
Space technology capacity building in support of SDG 2030 through CubeSat SharjahSat-l
The SHARJAH-SAT-1 would be the first CubeSat mission to be developed by the Sharjah Academy for Astronomy, Space Sciences, and Technology (SAASST)students and researchers, with the aim of not only designing, fabricating, testing & launching the CubeSat itself, but also building the capacities and expertise for future SAASST CubeSat missions as well. For the project, SAASST is working in close collaboration with an experienced international partner, the Istanbul Technical University, Space Systems Design and Test Laboratory which has already developed and launched 5 CubeSats into low earth orbit. Overall, the project, puts the human capacity development in its center, in support of UN SDG 2030 for an equal world
X-ray detector XRD on BeEagleSat and the development of the improved x-ray detector iXRD
Many interesting astrophysical objects are intense X-ray emitters. Hard X-ray observatories in various sizes have been operating in space and providing exciting scientific results that we cannot obtain in our laboratories on Earth. Nanosatellites with CdZnTe hard X-ray detectors have been launched into orbit as well, and the future holds great promise with such small satellites contributing significantly to high energy astrophysics. One of those satellites is the BeEagleSat which carried the X-ray detector (XRD)to low Earth orbit. The XRD has a 15⨯15⨯3 mm 3 volume CdZnTe detector, a cross-strip electrode design, a RENA readout chip controlled by an MSP 430 microcontroller. Due to a communication problem with the receiver, no science data could have been downloaded from the XRD. Recently, an improved version of the XRD has been designed (called the iXRD)and currently it is in the production phase. The improvements compared to the XRD are the larger volume crystal with almost three times the collecting area, a collimator to limit the field of view for focused scientific return, and a motherboard-daughterboard design to reduce electronic noise
It is possible to quantify the geometry of shock shapes from schlieren photographs to facilitate comparisons between experiments and numerical predictions
Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe
Numerical prediction of three-dimensional subsonic flows in ducts using the parabolized navier-stokes approach
Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe
Does Duke Activity Status Index help predicting functional exercise capacity and long-term prognosis in patients with pulmonary hypertension?
Background: To investigate the association of Duke Activity Status Index (DASI) with 6-minute walk test (6MWT) and WHO-Functional Class (WHO-FC) in patients with pulmonary hypertension (PH), as well as exploring whether DASI can discriminate between the patients with better and worse long-term prognosis according to 400 m cut-off score in 6MWT. Methods: Eighty-five medically stable PH patients who met eligibility criteria were included. All patients were evaluated using 6MWT and DASI. The prognostic utility of the DASI was assessed using univariate linear regression and receiver operating characteristic (ROC) curve analysis. Results: The DASI was an independent predictor for both 6MWT and WHO-FC, explaining 50% of variance in 6MWT and 30% of variance in WHO-FC class (p = 26 was the optimal cut-off value for better long-term prognosis, having sensitivity of 0.74 and a specificity of 0.88. Conclusions: The DASI is a valid tool reflecting functional exercise capacity in patients with PH. Considering its ability to discriminate between the patients with better or worse long-term prognosis, it may help identifying the patients at higher risk
Human and technological capacity building through the Sharjah-Sat-1 CubeSat project
Sharjah-Sat-1 is 3U+ CubeSat, carrying a primary payload consisting of an X-ray detector to study bright X-ray sources in our Galaxy and a dual camera system as a secondary, remote-sensing application payload. It is the first small satellite mission of the Sharjah Academy for Astronomy, Space Sciences, and Technology (SAASST) and the University of Sharjah (UoS), developed in close collaboration with Istanbul Technical University Space Systems Design and Test Laboratory (ITU-SSDTL) and Sabanci University (SU). Small satellites, especially CubeSat standard, have greatly interested universities and educational establishments due to their lower costs and shorter development time. This makes them ideal for engaging students in the design, testing, and operation of satellite missions and offers a unique first-hand experience in the space industry. The Sharjah-Sat-1 project has provided an essential basis for theoretical and hands-on knowledge of space technologies. This included various extensive workshops for the team of undergraduate students involved and public outreach programs on the topics of satellites and space systems. Additionally, the project has created a solid infrastructure at the Academy to develop further CubeSat missions in the future. Throughout the mission duration, the CubeSat laboratory at SAASST has been expanding and building the necessary facilities that are vital for its success. This includes the high-performance Workstation loaded with the required software to design, simulate and analyze the mission in the space environment, the cleanroom (ISO6 certified) to integrate and test the satellite subsystems, and the ground station (VHF/UHF) needed to communicate with CubeSat once it is in orbit. Furthermore, the participating students have been trained on how to use the software and the operation of the ground station in the scope of the Sharjah-Sat-1 mission. Ultimately, the human and technological capacities the project has built and all experience gained will certainly be transferred to future projects
SharjahSat-1 space-to-ground telecommunication operations
SharjahSat-1 is a collaborative research project by the Sharjah Academy for Astronomy, Space Science, and Technology (SAASST), University of Sharjah (UoS), Istanbul Technical University Space Systems Design and Test Laboratory (ITU-SSDTL), and Sabanci University (SU). The 3U+ CubeSat will host an improved X-ray Detector (iXRD) as the primary payload and a secondary payload system of a dual optical camera system. The X-ray detector's objective is to detect hard X-rays from very bright X-ray sources, and to study the solar coronal holes, whereas the camera system will provide a low-resolution remote sensing application. Although SharjahSat-1 would be the first CubeSat mission to be developed by SAASST and UoS, it aims to extend the experience for the following CubeSat missions. The anticipated launch date of the CubeSat is by the fourth quarter of 2022. Many parameters such as emission patterns, data rates, modulation schemes, and the dynamics of the satellites affect the completion of the communication links between the CubeSat and the ground station. Thus, it is crucial to consider all major and minor parameters while designing and performing telecommunication operations. SharjahSat-1 host a transmitter and a transceiver and their antennas to communicate the data from the payloads and telemetry through different frequency bands. It will perform these operations through S-band and VHF/UHF frequency ranges due to its payloads requirement of high data rates. Moreover, SAASST is equipped with an S-Band, a full-duplex VHF/UHF Ground Station, and a Software Defined Radio (SDR) ground station transceiver to fulfill such mission requirements and assure its success. Furthermore, a custom-console software was developed to control SharjahSat-1 while it is in orbit by sending commands to execute diverse types of operations that will directly affect the practicality of mission objectives. This paper comprises SharjahSat-1 communication subsystem design significance due to the requirements of the payloads. Then it will put forward the composition of the full-fledged SAASST Ground Segment equipped with technologically advanced hardware components that allow full automation during operations as it is remotely controlled. Finally, it will describe the developed custom-console software that aids the mission's operations to formulate a comprehensive End-to-End communication operations process