The slowly variable star FY Lacertae

Photometric observations and analysis of FY Lac were performed in order to determine the variability characteristics, using measurements taken at Loiano site of Bologna Astronomical Observatory and AAVSO data. The star shows a Long Term variability with a preliminary period of about 274 +/- 28 days and photometric characteristics compatible with a red M5 III giant star, with a temperature of 3420 K degrees.Comment: 9 page

Using interactive tools to create an enthusiasm for control in aerospace and chemical engineers

The efficacy of virtual laboratories in supporting student learning is now well accepted. This paper builds on that assumption and considers where there are obvious gaps in provision and a need for a response to typical student criticisms. Specifically here, the focus is on students who complete a control course and do not understand why they have studied it, why it is relevant and so forth. Four new interactive laboratories are introduced which are designed for aerospace engineers and chemical engineers. The former two focus on a context, to help aerospace students see a scenario where lead and lag design might be needed. The latter two, for chemical engineers, focus on uncertainty and why control is therefore essential to ensure good process outcomes

Bone fracture detection using electrical impedance tomography based on STEMlab Red Pitaya

Bone fractures can result in accidents, osteoporosis, bone cancer, or other conditions. X-Ray is a medical imaging technique often used to detect bone fractures. However, X-Rays can have radiation effects that harm patients, health workers, and the environment. Electrical impedance tomography (EIT) is a system that can obtain object images based on the electrical impedance distribution. In bone fractures, the proximal bone tissue experiences increased blood flow with local edema due to the inflammatory reaction which indicates the presence of a high conductivity diffusion material at the fracture location. EIT based on the STEMlab Red Pitaya module can be utilized to detect bone fractures. Red Pitaya serves as a controller, possessing a voltage generator, an oscilloscope, and 16 input/output pins that fulfill most of the EIT functions. To test the EIT-based system’s efficacy, a 3D-printed polylactic acid (PLA)-based bone phantom model was used. This model was placed on a cylindrical phantom filled with water as a substitute for soft tissue. The voltage data then are reconstructed using electrical impedance and diffuse optical reconstruction software (EIDORS), a MATLAB toolbox devoted to image reconstruction from impedance measurement results. The results of the reconstruction demonstrated that EIT based on the Red Pitaya STEMlab module could distinguish between normal bone and fractured bone

Performance comparison between signal digitizers and low-cost digital oscilloscopes: spectroscopic, pulse shape discrimination and timing capabilities for nuclear detectors

Signal digitizers revolutionized the approach to the electronics readout of radiation detectors in Nuclear Physics. These highly specialized pieces of equipment are designed to acquire the signals that are characteristic of the detectors in nuclear physics experiments. The functions of the several modules that were once needed for signal acquisition, can now be substituted by a single digitizer. As suggested by the name, with such readout modules, signals are first digitized (i.e. the signal waveform is sampled and converted to a digital representation) and then either stored or analyzed on-the-fly. The performances can be comparable or better than the traditional analog counterparts, in terms of energy, time resolution, and acquisition rate. In this work, we investigate the use of general-purpose digital oscilloscopes as signal digitizers for nuclear detectors. In order to have a proper comparison, we employ a distributed data acquisition system (DAQ), that standardizes the interface between the hardware and the on-line data analysis. The signals, from a set of typical radiation detectors, are digitized and analyzed with the very same algorithms in order to avoid biases due to different software analysis. We compare two traditional signal digitizers (CAEN DT5725 and CAEN DT5751) to two low-cost digital oscilloscopes (Digilent Analog Discovery 2, and Red Pitaya STEMLab 125-14), in terms of their capabilities for spectroscopy (energy resolution), time resolution, pulse shape discrimination, and maximum acquisition rate.Comment: 17 pages, 8 figures, 4 tables, Prepared for submission to JINS

Building a nuclear physics lab in the 21st century

For more than half a century, expensive and bulky modules (e.g. the standard NIM, Nuclear Instrumentation Modules) and electronic boards have been used in nuclear physics laboratory courses, in order to filter, shape and digitize the analog signals coming from particle detectors. Recently it has become technically possible to miniaturize these circuits within ASICs, but their high cost and specificity make them unsuitable in a didactic and general-purpose context. In this contribution we present an innovative system for reading and processing the signals produced by radiation detectors, which is based on simple, cheap and versatile components. The system is based on the "Red Pitaya STEMlab 125-14" a compact size board which implements: a CPU, a FPGA, a port for network connections (useful for remote access and control) and two 125 MS/s 14-bit digitizer channels. The software framework, necessary for the acquisition, processing, and storage of the signals, is based on the "ABCD" acquisition system. This systemwas experimentally tested in the Nuclear Physics Laboratory course of the Bachelor’s Degree in Physics at the Insubria University, in Como (Italy). In particular, it was used to read the signals produced by a silicon photodiode and a Ce:LaBr3 scintillator in alpha and gamma spectroscopy experiments. The system performance resulted to be equivalent to the one obtained with the traditional VME spectroscopic system. The main advantages of this new approach concern the compactness, versatility, and low cost, making it ideal also for high school laboratories

An open-source high-frequency lock-in amplifier

We present characterization of a lock-in amplifier based on a field programmable gate array capable of demodulation at up to 50 MHz. The system exhibits 90 nV/sqrt(Hz) of input noise at an optimum demodulation frequency of 500 kHz.The passband has a full-width half-maximum of 2.6 kHz for modulation frequencies above 100 kHz. Our code is opensource and operates on a commercially available platform