154 research outputs found

    A modified volumetric energy density–based approach for porosity assessment in additive manufacturing process design

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    Soundness of additively manufactured parts depends on a lot of process and geometrical parameters. A wrong process design leads to defects such as lack of fusion or keyhole porosity that have a detrimental effect on the mechanical properties of the printed parts. Process parameter optimization is thus a formidable challenge that requires in general a huge amount of experimental data. Among the others, heat source power and scan speed are the most defects-affecting parameters to be optimized. The energy density is used in literature to quantify their combination. Unfortunately, in different works it was demonstrated that it fails if used as design parameter mainly because it does not take into account the material properties and the interaction between heat source and the powder bed. In this contribution, a modified volumetric energy density equation that takes into account the powder-heat source interaction to optimize the combination of power-scan speed values for porosity assessment in powder bed fusion process design is proposed and verified on both AlSi10Mg alloy and Maraging steel 300

    A new clinical tool for assessing numerical abilities in neurological diseases: numerical activities of daily living

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    The aim of this study was to build an instrument, the numerical activities of daily living (NADL), designed to identify the specific impairments in numerical functions that may cause problems in everyday life. These impairments go beyond what can be inferred from the available scales evaluating activities of daily living in general, and are not adequately captured by measures of the general deterioration of cognitive functions as assessed by standard clinical instruments like the MMSE and MoCA. We assessed a control group (n = 148) and a patient group affected by a wide variety of neurological conditions (n = 175), with NADL along with IADL, MMSE, and MoCA. The NADL battery was found to have satisfactory construct validity and reliability, across a wide age range. This enabled us to calculate appropriate criteria for impairment that took into account age and education. It was found that neurological patients tended to overestimate their abilities as compared to the judgment made by their caregivers, assessed with objective tests of numerical abilities

    Improving water use efficiency in vertical farming: Effects of growing systems, far-red radiation and planting density on lettuce cultivation

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    Vertical farms (VFs) are innovative urban production facilities consisting of multi-level indoor systems equipped with artificial lighting in which all the environmental conditions are controlled independently from the external climate. VFs are generally provided with a closed loop fertigation system to optimize the use of water and nu-trients. The objective of this study, performed within an experimental VF at the University of Bologna, was to quantify the water use efficiency (WUE, ratio between plant fresh weight and the volume of water used) for a lettuce (Lactuca sativa L.) growth cycle obtained in two different growing systems: an ebb-and-flow substrate culture and a high pressure aeroponic system. Considering the total water consumed (water used for irrigation and climate management), WUE of ebb-and-flow and aeroponics was 28.1 and 52.9 g L-1 H2O, respectively. During the growing cycle, the contribution generated by the recovery of internal air moisture from the heating, ventilation and air conditioning (HVAC) system, was quantified. Indeed, by recovering water from the dehu-midifier, water use decreases dramatically (by 67 %), while WUE increased by 206 %. Further improvement of WUE in the ebb-and-flow system was obtained through ameliorated crop management strategies, in particular, by increasing planting densities (e.g., 153, 270 and 733 plants m-2) and by optimizing the light spectrum used for plant growth (e.g., adjusting the amount of far-red radiation in the spectrum). Strategies for efficient use of water in high-tech urban indoor growing systems are therefore proposed

    ELISA assay employing epitope-specific monoclonal antibodies to quantify circulating HER2 with potential application in monitoring cancer patients undergoing therapy with trastuzumab

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    Circulating HER2 extracellular domain (HER2 ECD) levels were proposed as a surrogate for HER2 tissue expression to monitor breast cancer patients for early relapse or responses to standard or HER2-targeted therapies, such as the monoclonal antibody (mAb) trastuzumab. Currently, available commercial ELISA assays for HER2 ECD rely on antibodies recognizing undisclosed or unknown epitopes. In this work, two ELISA assays employing MGR2 and MGR3 epitope-specific mAbs for HER2 ECD were developed and validated, showing good assay precision and linearity of the dose-response signal within the dynamic range of 0.19–12.50 ng mL−1 and detection limits of 0.76 and 0.75 ng mL−1 for the MGR2 and MGR3 assays, respectively. The developed assay showed a good agreement with two widely used commercial kits for HER2 ECD quantification in serum samples from breast cancer patients. A complete characterization of mAb-HER2 ECD interaction was performed by means of surface plasmon resonance using trastuzumab as control for both epitope mapping and kinetics analysis. The epitopes recognized by the two mAbs showed no overlap with trastuzumab, which was confirmed by trastuzumab interference analysis in serum samples. The method showed to be a practical approach to determine HER2 ECD with a high degree of sensitivity, reliability and recovery in samples containing mAbs-based therapies

    Assessment of the different types of failure on anterior cantilever resin-bonded fixed dental prostheses fabricated with three different materials: An in vitro study

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    background: resin-bonded fixed dental prosthesis (RBFDP) represents a highly aesthetic and conservative treatment option to replace a single tooth in a younger patient. The purpose of this in vitro study was to compare the fracture strength and the different types of failure on anterior cantilever RBFDPs fabricated using zirconia (ZR), lithium disilicate (LD), and PMMA-based material with ceramic fillers (PM) by the same standard tessellation language (STL) file. Methods: sixty extracted bovine mandibular incisives were embedded resin block; scanned to design one master model of RBFDP with a cantilevered single-retainer. Twenty cantilevered single-retainer RBFDPs were fabricated using ZR; LD; and PM. Static loading was performed using a universal testing machine. Results: the mean fracture strength for the RBFDPs was: 292.5 Newton (Standard Deviation (SD) 36.6) for ZR; 210 N (SD 37.6) for LD; and 133 N (SD 16.3) for PM. All the failures of RBFDPs in ZR were a fracture of the abutment tooth; instead; the 80% of failures of RBFDPs in LD and PM were a fracture of the connector. Conclusion: within the limitations of this in vitro study, we can conclude that the zirconia RBFDPs presented load resistance higher than the maximum anterior bite force reported in literature (270 N) and failure type analysis showed some trends among the groups

    White matter tract disconnection in Gerstmann's syndrome: Insights from a single case study

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    It has been suggested that Gerstmann's syndrome is the result of subcortical disconnection rather than emerging from damage of a multifunctional brain region within the parietal lobe. However, patterns of white matter tract disconnection following parietal damage have been barely investigated. This single case study allows characterising Gerstmann's syndrome in terms of disconnected networks. We report the case of a left parietal patient affected by Gerstmann's tetrad: agraphia, acalculia, left/right orientation problems, and finger agnosia. Lesion mapping, atlas-based estimation of probability of disconnection, and DTI-based tractography revealed that the lesion was mainly located in the superior parietal lobule, and it caused disruption of both intraparietal tracts passing through the inferior parietal lobule (e.g., tracts connecting the angular, supramarginal, postcentral gyri, and the superior parietal lobule) and fronto-parietal long tracts (e.g., the superior longitudinal fasciculus). The lesion site appears to be located more superiorly as compared to the cerebral regions shown active by other studies during tasks impaired in the syndrome, and it reached the subcortical area potentially critical in the emergence of the syndrome, as hypothesised in previous studies. Importantly, the reconstruction of tracts connecting regions within the parietal lobe indicates that this critical subcortical area is mainly crossed by white matter tracts connecting the angular gyrus and the superior parietal lobule. Taken together, these findings suggest that this case study might be considered as empirical evidence of Gerstmann's tetrad caused by disconnection of intraparietal white matter tracts

    PHYSIOLOGICAL QUALITY OF Syzygium cumini L. SEEDS DURING STORAGE

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    Syzygium cumini L. \ue9 uma \ue1rvore nativa da \ucdndia conhecida popularmente por jambol\ue3o, bastante cultivada como esp\ue9cie ornamental, apresenta propriedades medicinais e seus frutos s\ue3o comest\uedveis, no entanto, os estudos sobre a conserva\ue7\ue3o das sementes s\ue3o incipientes. O objetivo dessa pesquisa foi avaliar a qualidade fisiol\uf3gica das sementes de Syzygium cumini durante o armazenamento. O trabalho foi conduzido no laborat\uf3rio de an\ue1lise de sementes em ambiente protegido do Centro de Ci\ueancias Agr\ue1rias (CCA) da Universidade Federal da Para\uedba (UFPB), campus II, em Areia - PB. Os frutos foram despolpados e as sementes foram acondicionadas em sacos pl\ue1sticos duplos contendo substratos umedecidos: areia, vermiculita e areia+vermiculita (propor\ue7\ue3o 1:1), cada um com 10 e 20% de umidade e armazenados em c\ue2mara seca (19\ub15\ubaC e 74\ub120% UR) durante 30 dias. A cada seis dias, as sementes foram retiradas para a determina\ue7\ue3o do teor de \ue1gua e realiza\ue7\ue3o dos testes de emerg\ueancia, \uedndice de velocidade de emerg\ueancia, comprimento e massa seca de pl\ue2ntulas. As melhores condi\ue7\uf5es para a preserva\ue7\ue3o da qualidade fisiol\uf3gica das sementes de jambol\ue3o s\ue3o obtidas quando acondicionadas nos substratos (vermiculita e/ ou areia+vermiculita) umedecidos, mantendo-as vi\ue1veis durante 30 dias. E o substrato vermiculita+areia umedecido a 10% destaca-se por melhor preservar as caracter\uedsticas fisiol\uf3gicas.Syzygium cumini L. is a native Indian tree popularly known as \u201cjambol\ue3o\u201d, largely grown as ornamental, medicinal properties and its fruits are edible, however, studies on seed conservation are still insufficient. The objective of this research was to evaluate the physiological quality of Syzygium cumini seeds during storage. The work was performed at the seed testing laboratory and in the greenhouse of the Center for Agricultural Sciences (CCA) of the Federal University of Para\uedba (UFPB), Campus II, Areia -PB. The fruits were depulped and the seeds were placed in double plastic bags containing moistened (10 to 20% moisture) substrates: sand, vermiculite and sand+vermiculite (1:1). The plastic bags were stored in a dry chamber (19 \ub1 5 \ubaC and 74 \ub1 20 % RH) for 30 days. Every six days the seeds were removed for the determination of water content and seedling emergence test, emergence speed index, length and dry matter of seedling. The best conditions for the preservation of physiological seed quality of \u201cjambol\ue3o\u201d are obtained when seeds are packed in humid substrates (vermiculite and/or sand, vermiculite), and under this condition the seeds stay viable for 30 days. Vermiculite+sand with 10% of moisture stand out as the best treatment to preserve the physiological characteristics

    Energy aware software evolution for wireless sensor networks

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    Wireless Sensor Networks (WSNs) are subject to high levels of dynamism arising from changing environmental conditions and application requirements. Reconfiguration allows software functionality to be optimized for current environmental conditions and supports software evolution to meet variable application requirements. Contemporary software modularization approaches for WSNs allow for software evolution at various granularities; from monolithic re-flashing of OS and application functionality, through replacement of complete applications, to the reconfiguration of individual software components. As the nodes that compose a WSN must typically operate for long periods on a single battery charge, estimating the energy cost of software evolution is critical. This paper contributes a generic model for calculating the energy cost of the reconfiguration in WSN. We have embedded this model in the LooCI middleware, resulting in the first energy aware reconfigurable component model for sensor networks. We evaluate our approach using two real-world WSN applications and find that (i.) our model accurately predicts the energy cost of reconfiguration and (ii.) component-based reconfiguration has a high initial cost, but provides energy savings during software evolution
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