26 research outputs found

    A procedure for optimal calibration for a QCM electronic nose. Relation with specifications for pear quality.

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    The “Rome Tor Vergata” electronic nose has eight Quartz Microbalance Sensors. When a mass is absorbed or placed onto the quartz crystal surface, the oscillation frequency changes in proportion to the amount of mass. Despite previous studies, no QCM calibration statement has been made in relation to the sensitivity needed in the sensors for pear quality assessment. A calibration procedure has been designed and precision, sensitivity, specificity and reproducibility, on a QCM based electronic nose, evaluated. Using data of emission for pear, determinated by GC, it has been evaluated the extracted metrology features in relation to the specifications of the sensing device needed for quality assessment in pears

    Advanced characterization of a coffee fermenting tank by multi-distributed wireless sensors: spatial interpolation and phase diagrams.

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    In coffee processing the fermentation stage is considered one of the critical operations by its impact on the final quality of the product. However, the level of control of the fermentation process on each farm is often not adequate; the use of sensorics for controlling coffee fermentation is not common. The objective of this work is to characterize the fermentation temperature in a fermentation tank by applying spatial interpolation and a new methodology of data analysis based on phase space diagrams of temperature data, collected by means of multi-distributed, low cost and autonomous wireless sensors. A real coffee fermentation was supervised in the Cauca region (Colombia) with a network of 24 semi-passive TurboTag RFID temperature loggers with vacuum plastic cover, submerged directly in the fermenting mass. Temporal evolution and spatial distribution of temperature is described in terms of the phase diagram areas which characterizes the cyclic behaviour of temperature and highlights the significant heterogeneity of thermal conditions at different locations in the tank where the average temperature of the fermentation was 21.2 °C, although there were temperature ranges of 4.6°C, and average spatial standard deviation of ±1.21ºC. In the upper part of the tank we found high heterogeneity of temperatures, the higher temperatures and therefore the higher fermentation rates. While at the bottom, it has been computed an area in the phase diagram practically half of the area occupied by the sensors of the upper tank, therefore this location showed higher temperature homogeneit

    Prospective of Innovative Technologies for Quality Supervision and Classification of Roasted Coffee Beans

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    Color sorting is the major procedure employed for establish roast degree of coffee beans. However, color-based procedures have been proven to be ineffective, since coffee beans roasted to different degrees can present the same average readings in light reflectance measurements with significant quality variations. Besides to color, other major changes in beans are volume (swell), mass, form, bean pop and density. Eight samples of arabica coffee from Colombia and Guatemala have been roasted under slightly different conditions of time and temperature in order to obtain the same color classification. Sample analysis of data from nuclear magnetic resonance relaxometry show differences between samples in T1 and T2 parameters at cellular and subcellular level, and image analysis carried out on X-ray μCT leading to microestruture images corroborate differences in porosity and fissures presence among them, proving the potentiality of these technological solutions for sensing the microstructure of coffee to provide tools to enhance the roasting process

    Advanced Characterisation of a Coffee Fermenting Tank by Multi-distributed Wireless Sensors: Spatial Interpolation and Phase Space Graphs

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    The fermentation stage is considered to be one of the critical steps in coffee processing due to its impact on the final quality of the product. The objective of this work is to characterise the temperature gradients in a fermentation tank by multi-distributed, low-cost and autonomous wireless sensors (23 semi-passive TurboTag® radio-frequency identifier (RFID) temperature loggers). Spatial interpolation in polar coordinates and an innovative methodology based on phase space diagrams are used. A real coffee fermentation process was supervised in the Cauca region (Colombia) with sensors submerged directly in the fermenting mass, leading to a 4.6 °C temperature range within the fermentation process. Spatial interpolation shows a maximum instant radial temperature gradient of 0.1 °C/cm from the centre to the perimeter of the tank and a vertical temperature gradient of 0.25 °C/cm for sensors with equal polar coordinates. The combination of spatial interpolation and phase space graphs consistently enables the identification of five local behaviours during fermentation (hot and cold spots)

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    The European Low Frequency Survey. Observing the radio sky to understand the beginning of the Universe

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    International audienceIn this paper we present the European Low Frequency Survey (ELFS), a project that will enable foregrounds-free measurements of primordial BB-mode polarization to a level 103^{-3} by measuring the Galactic and extra-Galactic emissions in the 5--120 GHz frequency window. Indeed, the main difficulty in measuring the B-mode polarization comes not just from its sheer faintness, but from the fact that many other objects in the Universe also emit polarized microwaves, which mask the faint CMB signal. The first stage of this project will be carried out in synergy with the Simons Array (SA) collaboration, installing a 5.5--11 GHz coherent receiver at the focus of one of the three 3.5 m SA telescopes in Atacama, Chile ("ELFS on SA"). The receiver will be equipped with a fully digital back-end based on the latest Xilinx RF System-on-Chip devices that will provide frequency resolution of 1 MHz across the whole observing band, allowing us to clean the scientific signal from unwanted radio frequency interference, particularly from low-Earth orbit satellite mega-constellations. This paper reviews the scientific motivation for ELFS and its instrumental characteristics, and provides an update on the development of ELFS on SA

    The European Low Frequency Survey. Observing the radio sky to understand the beginning of the Universe

    No full text
    International audienceIn this paper we present the European Low Frequency Survey (ELFS), a project that will enable foregrounds-free measurements of primordial BB-mode polarization to a level 103^{-3} by measuring the Galactic and extra-Galactic emissions in the 5--120 GHz frequency window. Indeed, the main difficulty in measuring the B-mode polarization comes not just from its sheer faintness, but from the fact that many other objects in the Universe also emit polarized microwaves, which mask the faint CMB signal. The first stage of this project will be carried out in synergy with the Simons Array (SA) collaboration, installing a 5.5--11 GHz coherent receiver at the focus of one of the three 3.5 m SA telescopes in Atacama, Chile ("ELFS on SA"). The receiver will be equipped with a fully digital back-end based on the latest Xilinx RF System-on-Chip devices that will provide frequency resolution of 1 MHz across the whole observing band, allowing us to clean the scientific signal from unwanted radio frequency interference, particularly from low-Earth orbit satellite mega-constellations. This paper reviews the scientific motivation for ELFS and its instrumental characteristics, and provides an update on the development of ELFS on SA

    Astro2020 APC White Paper: The need for better tools to design future CMB experiments

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    International audienceThis white paper addresses key challenges for the design of next-decade Cosmic Microwave Background (CMB) experiments, and for assessing their capability to extract cosmological information from CMB polarization. We focus here on the challenges posed by foreground emission, CMB lensing, and instrumental systematics to detect the signal that arises from gravitational waves sourced by inflation and parameterized by rr, at the level of r103r \sim 10^{-3} or lower, as proposed for future observational efforts. We argue that more accurate and robust analysis and simulation tools are required for these experiments to realize their promise. We are optimistic that the capability to simulate the joint impact of foregrounds, CMB lensing, and systematics can be developed to the level necessary to support the design of a space mission at r104r \sim 10^{-4} in a few years. We make the case here for supporting such work. Although ground-based efforts present additional challenges (e.g., atmosphere, ground pickup), which are not addressed here, they would also benefit from these improved simulation capabilities
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