EXFI: a low cost Fault Injection System for embedded Microprocessor-based Boards

Evaluating the faulty behavior of low-cost embedded microprocessor-based boards is an increasingly important issue, due to their adoption in many safety critical systems. The architecture of a complete Fault Injection environment is proposed, integrating a module for generating a collapsed list of faults, and another for performing their injection and gathering the results. To address this issue, the paper describes a software-implemented Fault Injection approach based on the Trace Exception Mode available in most microprocessors. The authors describe EXFI, a prototypical system implementing the approach, and provide data about some sample benchmark applications. The main advantages of EXFI are the low cost, the good portability, and the high efficienc

Model-based reasoning for power system management using KATE and the SSM/PMAD

The overall goal of this research effort has been the development of a software system which automates tasks related to monitoring and controlling electrical power distribution in spacecraft electrical power systems. The resulting software system is called the Intelligent Power Controller (IPC). The specific tasks performed by the IPC include continuous monitoring of the flow of power from a source to a set of loads, fast detection of anomalous behavior indicating a fault to one of the components of the distribution systems, generation of diagnosis (explanation) of anomalous behavior, isolation of faulty object from remainder of system, and maintenance of flow of power to critical loads and systems (e.g. life-support) despite fault conditions being present (recovery). The IPC system has evolved out of KATE (Knowledge-based Autonomous Test Engineer), developed at NASA-KSC. KATE consists of a set of software tools for developing and applying structure and behavior models to monitoring, diagnostic, and control applications

A DLC/diamond bilayer approach for reducing the initial friction towards a highbearing capacity

Sliding contact mechanics is used to account for the net increase of the bearing capacity of high wear-resistant CVD diamond coatings when an outer layer of a DLC lubricant film is deposited on their top surface. Experimental results,namely the critical failure load, taken from reciprocating ball-on-plate tribological testing of such DLC/diamond bilayers, are on the basis of this statement. DC magnetron sputtering was used to grow thin DLC lubricant coatings (non-hydrogenated and hydrogenated varieties) on the top of CVD diamond films (microcrystalline and nanocrystalline types). The application of the von Mises maximum yield parameter (J2)1/2 criterion demonstrates to be an adequate method for designing low-friction and high-bearing capacity systems for high-demanding tribological applications. Calculation of (J2)1/2 supports that the most significant increase observed on the coatings’ bearing capacity (from 20 N to 60 N) takes place when microcrystalline diamond is coated by hydrogenated DLC that decreases the initial friction coefficient peak (from 0.76 to 0.41).Fundação para a Ciência e a Tecnologia (FCT

Direct digital manufacturing of nanocomposites

Additive manufacturing has surged in popularity as a route to designing and preparing functional parts. Depending on the parts function, certain attributes such as high mechanical performances may be desired. We develop a route for improving the mechanical properties of polymer devices, fabricated through additive manufacturing by combining electrospinning and stereo-lithography into one automated process. This process utilises the impressive mechanical properties of carbon nanotubes by encapsulating and aligning them in electrospun fibres. Composite fibres will be incorporated into polymer resins prepared with stereo-lithography, thereby providing resins that benefit from the composite fibres properties, enhancing their overall mechanical properties

Direct integration of micro-LEDs and a SPAD detector on a silicon CMOS chip for data communications and time-of-flight ranging

We present integration of singulated micron-sized light emitting diodes (micro-LEDs) directly onto a silicon CMOS drive chip using a transfer printing method. An 8x8 micro-LED device array with individual control over each pixel is demonstrated with modulation bandwidths up to 50 MHz, limited by the large modulation depth of the driver chip. The 2 kHz frame rate CMOS driver also incorporates a Single Photon Avalanche Diode device thus allowing detection and transmission functionality on a single integrated chip. Visible light communications at data rates up to 1 Mbps, and time-of-flight ranging with cm-scale resolution are demonstrated using this hybrid integrated system

Gigabit per second visible light communication based on AlGaInP red micro-LED micro-transfer printed onto diamond and glass

Full-color smart displays, which act both as a display and as a high-speed visible light communication (VLC) transmitter, can be realized by the integration of red-green-blue micron-sized light emitting diodes (micro-LEDs) onto a common platform. In this work, we report on the integration of aluminum gallium indium phosphide red micro-LEDs onto diamond and glass substrates by micro-transfer printing and their application in VLC. The device on-diamond exhibits high current density and bandwidth operation, enabled by diamond's superior thermal properties. Employing an orthogonal frequency division multiplexing modulation scheme, error-free data rates of 2.6 Gbps and 5 Gbps are demonstrated for a single micro-LED printed on-glass and on-diamond, respectively. In a parallel configuration, a 2x1 micro-LED array achieves error-free data rates of 3 Gbps and 6.6 Gbps, on-glass and on-diamond, respectively

First results from the Very Small Array -- IV. Cosmological parameter estimation

We investigate the constraints on basic cosmological parameters set by the first compact-configuration observations of the Very Small Array (VSA), and other cosmological data sets, in the standard inflationary LambdaCDM model. Using a weak prior 40 < H_0 < 90 km/s/Mpc and 0 < tau < 0.5 we find that the VSA and COBE_DMR data alone produce the constraints Omega_tot = 1.03^{+0.12}_{-0.12}, Omega_bh^2 = 0.029^{+0.009}_{-0.009}, Omega_cdm h^2 = 0.13^{+0.08}_{-0.05} and n_s = 1.04^{+0.11}_{-0.08} at the 68 per cent confidence level. Adding in the type Ia supernovae constraints, we additionally find Omega_m = 0.32^{+0.09}_{-0.06} and Omega_Lambda = 0.71^{+0.07}_{-0.07}. These constraints are consistent with those found by the BOOMERanG, DASI and MAXIMA experiments. We also find that, by combining all the recent CMB experiments and assuming the HST key project limits for H_0 (for which the X-ray plus Sunyaev--Zel'dovich route gives a similar result), we obtain the tight constraints Omega_m=0.28^{+0.14}_{-0.07} and Omega_Lambda= 0.72^{+0.07}_{-0.13}, which are consistent with, but independent of, those obtained using the supernovae data.Comment: 10 pages, 6 figures, MNRAS in pres

Mesenchymal stem/stromal cells : disrupting cell therapy storage and distribution with hypothermic preservation of adipose-derived mesenchymal stromal cells

Background & Aim: Cell and gene therapies (CGT) have reached new therapeutic targets but have noticeably high prices. Solutions to reduce production costs might be found in CGT storage and transportation since they typically involve cryopreservation, which is a heavily burdened process. Encapsulation at hypothermic temperatures (e.g.,2–8°C) could be a feasible alternative. In this study, we aim to determine the ability of alginate encapsulation to maintain cell viability, identity, and function in the context of MSC-based therapy manufacturing. Methods, Results & Conclusion: Adipose tissue-derived mesenchymal stromal cells (MSC(AT)) expanded using fetal bovine serum (FBS)- (MSC-FBS) or human platelet lysate (HPL)-supplemented mediums (MSC-HPL) were encapsulated in alginate beads (BeadReady™ kits kindly provided by Atelerix) for 30 min, 5 days, and 12 days. After bead release, cell recovery and viability were determined to assess encapsulation performance. MSC identity and functional immunophenotype, MSC tri-lineage differentiation potential, metabolic activity, and hematopoietic support capacity were determined and compared between timepoints. MSC(AT) were able to survive encapsulated for a standard transportation period of 5 days, with recovery values of 56 ± 5% for MSC-FBS and 77 ± 6% for MSC-HPL (which is a negligible drop compared to earlier timepoints). Importantly, MSC function did not suffer from encapsulation, with recovered cells showing robust differentiation potential, expression of immunomodulatory molecules, and hematopoietic support capacity. MSC(AT) encapsulation was proven possible for a remarkable 12 day period. There is currently no solution to completely replace cryopreservation in CGT logistics and supply chain, although encapsulation has shown potential to act as a serious competitor.info:eu-repo/semantics/publishedVersio