Implementation and testing of a passive magnetic attitude control system for the 3U AstroBio CubeSat orbiting in the Van Alllen belt

AstroBio CubeSat (ABCS) is a mission funded by the Italian Space Agency (ASI) aimed at validating novel lab-on-chip technology that would enable the use of micro- and nano-satellites as autonomous orbiting laboratories for research in astrobiology. The 3U CubeSat ABCS will be deployed by Vega-C launch system in a circular orbit with altitude of 5900 km and inclination of 70 degrees which crosses the harsh radiative environment of the inner Van Allen belt. In fact, the operative life of ABCS is expected to be significantly shorter than Low Earth Orbit (LEO) CubeSats, therefore a passive magnetic attitude control system (PMACS) was designed to (i) detumble the satellite and (ii) control its attitude to maximize the exposure of the body-mounted solar panels to the solar radiation. The PMACS consists of permanent magnets, producing a control torque rotating the satellite in the direction of the geomagnetic field vector, and soft-magnetic alloy strips, or hysteresis strips, performing the detumbling and stabilization of the satellite. The characterization of the hysteresis strips is not trivial and pivotal for estimating the performance of the PMACS. In this work, the hysteresis loop and the magnetic permeability for the hysteresis strips were determined experimentally using a Helmholtz cage facility with feedback control. Once characterized, the magnetic devices were installed onto a test unit of ABCS and integrated to a spherical air-bearing facility, which allows friction-less rotation. The use of the air-bearing together with the Helmholtz cage, recreating the magnetic field that will be experienced by ABCS in orbit, allows testing the PMACS in an environment which is significantly similar to the real operative one. The PMACS was tested under several detumbling conditions and experimental data allowed a quantitative evaluation the dissipative effect due to magnetic hysteresis, contributing in determining the optimal configuration for the PMACS devices

Autonomous Microfluidic Capillary Network for on Chip Detection of Chemiluminescence

This work reports on the design, simulation and fabrication of an autonomous microfluidic network. It is a part of a highly integrated, new analytical platform for the multiparametric detection of bio-organic molecules in extra-terrestrial environment. The proposed microfluidic system, made in SU-8 3050, allows to obtain an autonomous microfluidic network able to have simultaneous capillary filling and fresh solution into each site of detection avoiding cross-contamination among different sites. Computational Fluid Dynamics (CFD) simulations have been carried in order to verify the proper operation of the designed microfluidic network and to optimize it. Technological processes have been refined and adapted in order to ensure good adhesion, using low-temperature and low-pressure bonding avoiding the risk of breaking the glass slides. Experiments have been conducted to verify the autonomous capillary filling of the entire network and its rinsing with buffer solution. The experimental results are in good agreement with the simulations

Astrobio cubesat: Enabling technologies for astrobiology research in space

AstroBio CubeSat (ABCS) is a 3U CubeSat that will operate within the internal Van Allen belt and it should be the first attempt to conduct biochemical experiments on a nanosatellite platform and in a so extremely harsh environment. Performing astrobiology research in space is surely challenging due to limited volumes, limited access, and stressors such as ionizing radiation and lack of convection. Moreover, experiments should be performed autonomously especially on CubeSat missions. This interdisciplinary field requires also a comprehensive, integrated understanding of biological, biochemical and planetary phenomena. To meet the requirements arising from this scenario, ABCS satellite integrates several innovative solutions ranging from optimized experimental protocol to peculiar system level arrangements. The core of ABCS payload will be a lab-on-chip device consisting of a glass substrate on which a series of lateral flow immuno-assay (LFIA) strips on nitrocellulose support are attached. LFIA strips will be functionalized with biomolecules, immobilized in specific test areas, that will be sensed by means of chemiluminescent (CL) reactions. To avoid degradation of assay chemicals these will be deposited in a non-permanent fashion in a dry form in the initial part of the strips. On-chip detection of the analytical chemiluminescent signal, that occurs at test areas, is performed by means of hydrogenated amorphous silicon photodiodes. A custom low noise front-end readout board is employed for the biasing of the photodiode array and the readout of the photocurrents signal that contains the analytical information. In addition, it allows to interface the chip with the on-board computer. To carry out experiments in a stand-alone fashion, a third electronic board, stacked over the former, hosts a set of micropumps for the delivery of reagents across the device. Payload operation requires an ambient-pressure environment which is ensured by an aluminium box, hermetically sealed with an indium wire gasket. The box also provides shielding capability from the environment ionizing radiation. In this work an over-view of the engineering solutions employed to meet the requirements of a CubeSat application is presented

Dispositivo e metodo per il campionamento e la rilevazione di un agente patogeno nell'aria

l sistema proposto ha lo scopo di campionare l’aria presente principalmente in luoghi chiusi ( stanze di ospedale, supermercati, uffici, ascensori, metropolitane, ecc.) e di verificare l’eventuale presenza di agenti patogeni, ed in particolare del SARS-CoV-2 virus. Il sistema si basa su una catena di tre moduli, da interfacciare ed integrare in un sistema compatto, specifici per le funzioni di: 1) aspirazione e campionamento dell’aria; 2) microfluidica per il pre-trattamento e selezione dell’analita; 3) dispositivo lab-on-chip per l’amplificazione e il rilevamento degli acidi nucleici del virus tramite Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) in tempo reale.The proposed system aims to sample the air present in closed spaces (hospital rooms, supermarkets, offices, elevators, subways, etc.) and to verify the possible presence of pathogens, and in particular of SARS-CoV -2 virus. The system is based on a chain of three modules, to be interfaced and integrated into a compact system, specific for the following functions: 1) air suction and sampling; 2) microfluidics for pre-treatment and analyte selection; 3) lab-on-chip device for the amplification and detection of virus nucleic acids through real-time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)

HENON: the HEliospheric pioNeer for sOlar and interplanetary threats defeNce

International audienc

HENON: the HEliospheric pioNeer for sOlar and interplanetary threats defeNce

International audienc

Energy content and carbon emission audit of building materials

The main thesis examined in this research is that "the embedded energy of construction is much more significant than the operational energy for buildings in a tropical country such as Sri Lanka". All building elements (e.g. brickwall), materials (e.g. bricks) and "primitive" raw materials (e.g. clay) are placed in an aggregation-decomposition hierarchy. The process analysis carried out here basically captures most of the energy inputs associated with levels 1 and 2 in the IFIAS (1974) scheme, and accounts for around 90% of the embedded energy in a product. These calculations are based on Tonnes of Oil Equivalent (TOE). The data required to estimate these embedded energies were collected from building materials manufacturers. A computerised database was implemented using a relational database management system. This can be used to represent and calculate the embedded energies and carbon coefficients of building materials and elements that are hierarchically arranged. It can also handle multiple sources of data and perform calculations to give the average, maximum and minimum embedded energies, which are also classified according to fuel type and process stage. Though the analysis was done assuming that the final building is located in the City of Colombo, these database values can be used, with some caution, for buildings even outside the Colombo City or District. The embedded energy requirements were also calculated on the basis of the lowest quality energy (bio-equivalent energy), in addition to the more conventional basis of TOE. According to energy quality calculations carried out (based on efficiency considerations), 1GJ of energy from electricity is equivalent to 5 GJ of biomass energy, 1 GJ of fossil fuel energy is equivalent to 1.8 GJ of biomass energy and 1 GJ of electrical energy is equivalent to 2.78 GJ of fossil fuel energy. It is seen that the price per unit of biomass energy based on the actual prices of products is around one third of the actual price per unit of biomass energy. For fossil fuel and electricity on the other hand, the actual prices of products are much higher than the actual prices of the energy sources used for their production. In order to minimise adverse energy effects and to give a beneficial effect to halting global warming, policy measures to promote timber products are desirable. It is also seen that though materials which use timber fuels (e.g. bricks and tiles) consume more energy, the use of timber fuels is more competitive when compared on a bio-equivalent unit basis. Furthermore, with respect to carbon emissions, wood fuels are considered to be self sustaining. The use of timber, whether as a construction material or a fuel, will require properly planned re-forestation strategies. The energy contribution from walls for a typical two storey house is from 10 - 44%; for a single storey house it is from 29 - 49%. The contribution from roofs for the two storey house is from 4 - 7%, whereas it is 8 - 16% for the single storey house. The contribution from windows is 0.6 - 3% for the single storey house and 0.2 - 4.5% for the two storey. house. The contribution from the floor slab for the two storey house is 6 - 7%. The above ranges are a result of the difference of the between the use of low and high energy materials. The ratio between total embedded energy and annual operational energy for the buildings selected lies between 14 to 35 for the houses while for an office building with air conditioning loading it is 5. Though air conditioning has a large contribution towards the annual operational energy of a building, the total number of air conditioned buildings are small for a developing country such as Sri Lanka. Nevertheless, the results of the analysis show that the focus of energy efficient designs for buildings with air conditioning has to be on the operational energy. On the other hand, for houses, which are largely not air conditioned, the way to promote efficiency is by reducing the embedded energy through the appropriate choice of building materials. This is borne out not only by the high ratio of construction to operational energy ratio obtained, but also by the fact that the ratios for houses with low energy materials is almost half those for the houses with high energy materials. Key Words : Embedded Energy, Process Analysis, Building Materials, Carbon Emissions, Energy Databas