Search Results (16)

This work aims to evaluate the feasibility of using a COTS-embedded computer as an on-board computer (OBC) for nanosatellites in academic projects. The prototype is based on the BeagleBone Black board, which runs the cFS flight-mission software on the RTEMS operating system. For evaluation purposes, 15.9 MeV proton-accelerated radiation tests were performed at the CNA facility to obtain the soft-error rate of the DDR3 SDRAM. Results show the presence of bit-flips in memory cells, leading to error propagation, and a burst of errors produced by SEEs, affecting the control logic of the SDRAM memory. Despite the errors and accumulated dose, the board continued to function normally, with a worst-case FIT indicating that one failure every two years is expected in the SDRAM memory. This study suggests the possibility of using BeagleBone Black as an OBC for LEO. In addition, the article provides clues on how redundancy-based fault tolerance can be implemented. Full article

This paper proposes a fault-tolerant flexible manufacturing system (FMS) that features a dual-level fault tolerance mechanism at both the workcell and system levels to enhance reliability. The workcell controller was implemented on a Field Programmable Gate Array (FPGA). Reconfigurable duplication was used as the first level of fault tolerance at the workcell level. It was shown how to detect and recover from FPGA faults such as Single Event Upsets (SEUs), hard faults, and Single Event Functional Interrupts (SEFIs). The prototype of the workcell controller was successfully implemented using two Zybo Z7-20 AMD boards and an Arduino DUE. Petri Nets were used to prove that controller reliability increased by 346% after 1440 operational hours. The second level of fault tolerance was at the FMS level; the Supervisor (SUP) took over the responsibilities of any malfunctioning workcell controller. Riverbed software was used to prove that the system successfully met the end-to-end delay requirements. Finally, Matlab showed that there is a further increase in performability. Full article

As the feature size of integrated circuit decreases, the critical charge of single-event effect decreases as well, making nano-scale devices more susceptible to the high-energy charged particles during their application in space. Here, we study the electron-induced single-event effect in 28 nm static random-access memory (SRAM)-based field programmable gate array (FPGA) utilizing high-energy electrons with energy of 1 MeV~5 MeV. The experimental results demonstrate that the 3 MeV electrons can cause single-event functional interrupts (SEFIs) in FPGA, while the electrons with other energies cannot. To further explore the mechanism of electron-induced SEFIs in this nanoscale FPGA, we combined Monte Carlo, Technology Computer-Aided Design (TCAD), and Simulation Program with Integrated Circuit Emphasis (SPICE) simulations. It is revealed that the SEFI was mainly caused by the direct ionization effect of high-energy electrons, and the SEFI was related to the interactions between multiple sensitive nodes. Full article

Ionizing radiation induces the degradation of electronic systems. For memory devices, this phenomenon is often observed as the corruption of the stored data and, in some cases, the occurrence of sudden increases in current consumption during the operation. In this work, we propose enhanced experimental instrumentation to perform in-depth Single-Event Effects (SEE) monitoring and analysis of electronic systems. In particular, we focus on the Single-Event Latch-up (SEL) phenomena in memory devices, in which current monitoring and control are required for testing. To expose the features and function of the proposed instrumentation, we present results for a case study of an SRAM memory that has been used on-board PROBA-V ESA satellite. For this study, we performed experimental campaigns in two different irradiation facilities with protons and heavy ions, demonstrating the instrumentation capabilities, such as synchronization, high sampling rate, fast response time, and flexibility. Using this instrumentation, we could report the cross section for the observed SEEs and further investigate their correlation with the observed current behavior. Notably, it allowed us to identify that 95% of Single-Event Functional Interrupts (SEFIs) were triggered during SEL events. Full article

Background: The Endometriosis Fertility Index (EFI), is a crucial validated surgical tool used for predicting fertility outcomes in women with endometriosis. This study aims to assess the concordance between a preoperative clinical and instrumental EFI evaluation (uEFI) and the EFI score obtained during an exploratory laparoscopy prior to surgery (sEFI). Methods: This study presents preliminary data from a broader observational cohort study. The Least Function score for the uEFI was calculated using a modified version of the original surgical EFI by incorporating a clinical examination, advanced ultrasound, and hysterosalpingo-foam sonography (HyFoSy). Results: The preoperative estimation of the EFI (uEFI) demonstrated a high concordance (k = 0.695, ρ_s = 0.811) with the sEFI. Remarkably, the surgical interventions led to a significant improvement in the EFI values, with 80% of the intermediate EFI transitioning to a high level, thereby highlighting the positive impact of surgery on fertility outcomes. Conclusion: This study highlights the accuracy of preoperative EFI estimation (uEFI) and its strong agreement with intraoperative assessment. It underscores the potential of a preoperative management tool to guide the allocation of infertile women with endometriosis to operative laparoscopy, direct assisted reproductive technology (ART), or spontaneous attempts at pregnancy. Full article

To explore new strategies for optimizing China’s food cultivation structure, this study empirically investigates the relationship between the food import structure and China’s food cultivation structure from the perspective of water conservation based on factor endowments theory. The following conclusions are drawn: (i) Overall, the water-intensive food cultivation structure (WFCS) in South China and the middle and lower reaches of the Yangtze River shows a slightly upward trend and is obviously at a higher level. The WFCS in the Huang-Huai-Hai and Northwest regions shows a decreasing trend and is obviously at a lower level. (ii) The structural effects of food imports (SEFI) can effectively reduce the proportion of water-intensive food cultivation (WFC). Furthermore, every 100,000 tons of food imports will, on average, reduce the proportion of water-intensive food cultivation in the region by 0.161%. The negative effect of the SEFI on the proportion of WFC in the northern region and the major food-producing regions is stronger than that in the southern region and the non-major food-producing regions. (iii) The quantile regression reveals that the marginal role played by the SEFI is progressively stronger in regions with a higher proportion of WFC. This is because in regions with a low proportion of water- and land-intensive food cultivation, regional resource endowments are still sufficient to support the production. However, as the proportion of such food cultivation increases, the regional resource endowment will have difficulty supporting normal production. In this case, the negative effect of the SEFI on the proportion of WFC will be stronger. (iv) Driven by profits, some provinces import food and then dispatch it to adjacent regions. Thus, the SEFI has a spatial spillover effect on China’s food cultivation structure. This study verifies the applicability of factor endowments theory in the field of food trade, which not only extends the boundary of research into food import structure but also provides planning suggestions for China’s food cultivation structure. Full article

Single Event Functional Interrupt (SEFI) poses a severe threat to the normal operation of spacecraft. This paper investigates SEFI in Analog-to-Digital Converters (ADCs) with storage units using precision positioning of pulsed lasers. Based on the experiment, it was discovered that a bit flip in the configuration registers in ADCs results in changes in parameters such as digital filter frequency, operating mode, and gain, leading to an upward or downward offset of ADC output codes. Similarly, a bit flip in the calibration registers also causes ADC output codes to shift upwards or downwards, or even output a value of zero. Furthermore, it was observed that SEFI phenomena can occur due to current latch-up in ADC input pins, causing the inability to read or write data in ADC storage units. This current latch-up can be resolved through power cycling or configuring the pins into a high-impedance state. This work highlights the significance of SEFI phenomena in ADCs, emphasizing the serious threat posed by storage unit flipping-induced SEFI to the proper functioning of ADCs. Moreover, the SEFI phenomenon caused by current latch-up in input pins is difficult to detect in practice, making it highly elusive. Once it occurs, it severely impacts the functionality of ADCs. Full article

Malnutrition is related to poor outcomes. Food intake semi-quantitative assessment is helpful for malnutrition screening. Aims: to assess maintenance over one month of one-day semi-quantitative assessment of food intake (primary aim) and its performance in diagnosing malnutrition (secondary aim) in older people living in a nursing home. Food portions consumed at lunch and dinner were measured during 20 days by the Simple Evaluation of Food Intake (SEFI)^® assisted by photography (SEFI^®-AP) in 70 residents. Nutritional status was assessed in each patient during the first week of food intake monitoring according to Global Leadership Initiative on Malnutrition criteria. Food intake was decreased, i.e., SEFI^®-AP < 7, in 39% (n = 27/73) of patients. According to the methods, 36 to 48% (n = 25 to 33/73) of patients had malnutrition, and 6 to 37% (n = 4 to 25/73) sarcopenia. According to a generalized linear model on ranks with repeated measures, the SEFI^®-AP medians of lunch (p = 0.11) and means of lunch and dinner (p = 0.15) did not vary over time. Day 3 SEFI^®-AP anticipated decreased food intake from days 4 to 20, with a sensitivity of 78% (95% confidence interval (CI), 62–94), a specificity of 30% [95%CI, 17–44] and positive and negative predictive values of 41% [95%CI, 28–55] and 68% [95%CI, 48–89]. The performance of SEFI^®-AP for diagnosis of malnutrition using calf circumference <31 cm as a phenotypic criterion was correct: area under the curve = 0.71 [95%CI, 0.59–0.83]. SEFI^®-AP sensitivity was better if ≤9.5 than <7, and inversely for specificity. The food intake of older people living in nursing homes is stable over one month. One-day SEFI^®-AP correctly anticipates food intake during the following month and predicts diagnosis of malnutrition. Any decrease in food intake should lead to suspect malnutrition. Full article

Soft errors induced by radiation are the major reliability threat for SRAM-based field-programmable gate arrays (FPGAs). A more detailed analysis of the soft error sensitivity of the 40 nm SRAM-based FPGA was performed. Experimental methods for the configurable logic module, configure memory cells, and block RAM have been introduced for measuring the single event effects (SEEs) induced by alpha particles using a ²⁴¹Am radiation source. The single event upset (SEU) and single event functional interrupt (SEFI) cross sections of different functional blocks have been calculated to discuss the failure mechanisms of the FPGA. The SEEs test results for the FPGA device based on the 40 nm CMOS process are significant. Full article

A cell-level radiation hardening by design (RHBD) method based on commercial processes of single event transient (SET) and single event upset (SEU) is proposed in this paper, in which new radiation-hardened D-type flip-flops (DFFs) are designed. An application-specific integrated circuit (ASIC) of a million gates level is developed based on DFFs, and SEU and single event functional interruption (SEFI) heavy-ion radiation tests are carried out. The experimental results show that the new DFF SEU ability is increased by 63 times compared with the DICE-designed DFF, and is three orders of magnitude higher than the redundantly designed DFF. The SEFI ability of the ASIC designed by the new DFF is 2.6 times higher than the circuit hardened by the TMR design. Full article

Detection of microbial contamination in water is imperative to ensure water quality. We have developed an electrochemical method for the detection of E. coli using bi-functional magnetic nanoparticle (MNP) conjugates. The bi-functional MNP conjugates were prepared by terminal-specific conjugation of anti-E. coli IgG antibody and the electroactive marker ferrocene. The bi-functional MNP conjugate possesses both E. coli-specific binding and electroactive properties, which were studied in detail. The conjugation efficiency of ferrocene and IgG antibodies with amine-functionalized MNPs was investigated. Square-wave voltammetry enabled the detection of E. coli concentrations ranging from 10¹–10⁷ cells/mL in a dose-dependent manner, as ferrocene-specific current signals were inversely dependent on E. coli concentrations, completely suppressed at concentrations higher than 10⁷ cells/mL. The developed electrochemical method is highly sensitive (10 cells/mL) and, coupled to magnetic separation, provides specific signals within 1h. Overall, the bi-functional conjugates serve as ideal candidates for electrochemical detection of waterborne bacteria. This approach can be applied for the detection of other bacteria and viruses. Full article

The distribution of myosin VIII ATM1 tail in association with the plasma membrane is often observed in coordination with that of cortical microtubules (MTs). The prevailing hypothesis is that coordination between the organization of cortical MTs and proteins in the membrane results from the inhibition of free lateral diffusion of the proteins by barriers formed by MTs. Since the positioning of myosin VIII tail in the membrane is relatively stable, we ask: can it affect the organization of MTs? Myosin VIII ATM1 tail co-localized with remorin 6.6, the position of which in the plasma membrane is also relatively stable. Overexpression of myosin VIII ATM1 tail led to a larger fraction of MTs with a lower rate of orientation dispersion. In addition, collisions between MTs and cortical structures labeled by ATM1 tail or remorin 6.6 were observed. Collisions between EB1 labeled MTs and ATM1 tail clusters led to four possible outcomes: 1—Passage of MTs through the cluster; 2—Decreased elongation rate; 3—Disengagement from the membrane followed by a change in direction; and 4—retraction. EB1 tracks became straighter in the presence of ATM1 tail. Taken together, collisions of MTs with ATM1 tail labeled structures can contribute to their coordinated organization. Full article

Sustainable antibacterial–antioxidant films were prepared using in situ graftings of silica nanoparticle (SNP) precursors with covalently attached bioactive agents benzoic acid (ba) or curcumin (cur) on polyvinyl alcohol (PVA). The modified PVA-SNP, PVA-SNP-ba and PVA-SNP-cur films were characterized using spectroscopic, physicochemical and microscopic methods. The prepared films showed excellent antibacterial and antioxidant activity, and increased hydrophobicity providing protection from undesired moisture. The PVA-SNP-ba films completely prevented the growth of the foodborne human pathogen Listeria innocua, whereas PVA-SNP-cur resulted in a 2.5 log reduction of this bacteria. The PVA-SNP-cur and PVA-SNP-ba films showed high antioxidant activity of 15.9 and 14.7 Mm/g TEAC, respectively. The described approach can serve as a generic platform for the formation of PVA-based packaging materials with tailor-made activity tuned by active substituents on silica precursors. Application of such biodegradable films bearing safe bioactive agents can be particularly valuable for advanced sustainable packaging materials in food and medicine. Full article

Electronic circuits in harsh environments, such as space, are affected by soft errors produced by radiation. A single event functional interrupt (SEFI) can affect the behavior of a memory chip, with one or more rows, columns or even the whole device producing a wrong value when reading a set of stored bits. This problem may affect raw Bayer images stored in satellites and other spacecraft. In this paper, we present a methodology to analyze how different interpolation algorithms behave when they try to reconstruct the affected Bayer images into standard red, green and blue (RGB) images. This methodology can be used to compare and develop new fault-tolerant algorithms. The proposed methodology has been illustrated by studying a subset of interpolation algorithms. The results obtained from this example show that the interpolation algorithms that traditionally offer better results in a normal operation (in the absence of errors) are not always the best when SEFI errors are present in the Bayer images. Full article

The olfactory receptor neurons of insects and vertebrates are gated by odorant receptor (OR) proteins of which several members have been shown to exhibit remarkable sensitivity and selectivity towards volatile organic compounds of significant importance in the fields of medicine, agriculture and public health. Insect ORs offer intrinsic amplification where a single binding event is transduced into a measurable ionic current. Consequently, insect ORs have great potential as biorecognition elements in many sensor configurations. However, integrating these sensing components onto electronic transducers for the development of biosensors has been marginal due to several drawbacks, including their lipophilic nature, signal transduction mechanism and the limited number of known cognate receptor-ligand pairs. We review the current state of research in this emerging field and highlight the use of a group of indole-sensitive ORs (indolORs) from unexpected sources for the development of biosensors. Full article