861 research outputs found

    Preliminary Assessment of Sorption Capacity on Solid CO2-Sorbents at Conditions for Sorption-Enhanced Processes

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    This work aims to assess solid sorbent capacity to operate CO2 capture under industrial conditions relevant to biogas/bio-syngas upgrading systems to green H2 and food-grade CO2 through Sorption-Enhanced Water Gas Shift (SEWGS) technologies. The pursued degree of innovation is the process intensification to remove CO2 in a more sustainable industrial practice reducing the CO2 footprint of a potential H2 production process. A lab-scale apparatus is appropriately designed and built to operate at relevant industrial scale conditions. The core of the system is a fixed-bed reactor equipped with mass flow meters/controllers and online gas analyzers. CO2 capture experiments were carried out to investigate the effect of pressure (1.0-1.4 MPa) on different commercial and synthesized solid sorbent materials (hydrotalcite-like compounds). The best sorbent is a commercial hydrotalcite impregnated with 20 wt% of K2CO3, with an average sorption capacity of 0.85 mmolCO2/gad at 1.4 MPa and 623 K. The explored conditions are compatible with an industrial operation where syngas is available at low-to-moderate pressure

    Bismuth-Gold absorber for large area TES spiderweb bolometer

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    Large area spiderweb bolometer of about one centimetre diameter are required for matching multimode or quasi-optical cavities in microwave antenna for CMB measurements as proposed for the Large Scale Polarization Explorer balloon borne sky survey at 140, 220, 250 GHz. Possible applications at low frequencies, 40 GHz or less, in single mode are also foreseen. The main drawback of such large absorber is the achievement of an optimal trade-off among the thermal properties, like fast internal thermal diffusivity, heat capacity and milli-second recovery time and EM characteristics, like the matching impedance and EM power dissipation. In parallel with standard micropatterned gold film absorber deposited onto silicon nitride membrane, we have tested the Bismuth Gold in order to reduce the heat capacity even if with an increase of resistivity. Films of Bismuth Gold may have low resistivity under application of a proper post-production thermal cycle. We present the fabrication method of Bismuth Gold films for our microwave absorbers and the bolometer characterization at low temperature

    Fluidized bed gasification of biomass from plant-assisted bioremediation: Fate of contaminants

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    Fluidized-bed gasification (FBG) of Phyto-assisted Bioremediation (PABR) biomass is analyzed focusing on the contaminants' dispersion. Poplar pruning coming from an area contaminated by polychlorinated biphenyls (PCBs) and heavy metals (HM) are considered. The biomass analysis showed relevant contents in HMs, especially Cd and Cr, and no significant PCB content. FBG process was analyzed to: a) track pollutants, b) detect contaminants in the FBG and c) investigate the HMs concentration in the produced streams. The results showed that most of the metals are concentrated in the ashes collected in the bottom of the reactor (Pb, Cd, Cu, Cr), or in the cyclone (B, Na, Mg, Al, K and Fe). Interestingly, metals are also released by the olivine bed (Mg, Fe, Ni and Al) and transported downstream. Consistent fractions of Zn and Fe (also Cu) were detected in the fugitive ashes. As for the Volatile Organic Compounds (VOC) concentration, we noted similarities between PABR and virgin biomass syngas streams. A reduced-scale process was carried out in TGA-DTA to investigate the potential of such technique in reproducing the main features of the FBG process. Comparable results were obtained, thus suggesting its possible application for small-scale preliminary assessment of FBG process

    A review of implant provision for hypodontia patients within a Scottish referral centre

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    Background: Implant treatment to replace congenitally missing teeth often involves multidisciplinary input in a secondary care environment. High quality patient care requires an in-depth knowledge of treatment requirements. Aim: This service review aimed to determine treatment needs, efficiency of service and outcomes achieved in hypodontia patients. It also aimed to determine any specific difficulties encountered in service provision, and suggest methods to overcome these. Methods: Hypodontia patients in the Unit of Periodontics of the Scottish referral centre under consideration, who had implant placement and fixed restoration, or review completed over a 31 month period, were included. A standardised data collection form was developed and completed with reference to the patient's clinical record. Information was collected with regard to: the indication for implant treatment and its extent; the need for, complexity and duration of orthodontic treatment; the need for bone grafting and the techniques employed and indicators of implant success. Conclusion: Implant survival and success rates were high for those patients reviewed. Incidence of biological complications compared very favourably with the literature

    The personal norm of reciprocity

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    Reciprocity is here considered as an internalized social norm, and a questionnaire to measure individual differences in the internalized norm of reciprocity is presented. The questionnaire, Personal Norm of Reciprocity (PNR), measures three aspects of reciprocity: positive reciprocity, negative reciprocity, and beliefs in reciprocity. The PNR has been developed and tested in two cultures, British and Italian, for a total of 951 participants. A cross-cultural study provides evidence of good psychometric properties and generalizability of the PNR. Data provide evidence for criterion validity and show that positive and negative reciprocators behave in different ways as a function of the valence (positive or negative) of the other's past behaviour, the type of feasible reaction (reward versus punishment), and the fairness of their reaction. Copyright (C) 2002 John Wiley Sons, Ltd

    Multi‐scale studies of 3d printed Mn–Na–W/SiO2 catalyst for oxidative coupling of methane

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    This work presents multi-scale approaches to investigate 3D printed structured Mn–Na–W/SiO_{2} atalysts used for the oxidative coupling of methane (OCM) reaction. The performance of the 3D printed catalysts has been compared to their conventional analogues, packed beds of pellets and powder. The physicochemical properties of the 3D printed catalysts were investigated using scanning electron microscopy, nitrogen adsorption and X-ray diffraction (XRD). Performance and durability tests of the 3D printed catalysts were conducted in the laboratory and in a miniplant under real reaction conditions. In addition, synchrotron-based X-ray diffraction computed tomography technique (XRD-CT) was employed to obtain cross sectional maps at three different positions selected within the 3D printed catalyst body during the OCM reaction. The maps revealed the evolution of catalyst active phases and silica support on spatial and temporal scales within the interiors of the 3D printed catalyst under operating conditions. These results were accompanied with SEM-EDS analysis that indicated a homogeneous distribution of the active catalyst particles across the silica support

    The Effect of Fish Oil Supplementation on Resistance Training-induced Adaptations

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    Background: Resistance exercise training (RET) is a common and well-established method to induce hypertrophy and improvement in strength. Interestingly, fish oil supplementation (FOS) may aug-ment RET-induced adaptations. However, few studies have been conducted on young, healthy adults. Methods: A randomized, placebo-controlled design was used to determine the effect of FOS, a concentrated source of eicosapen-taenoic acid (EPA) and docosahexaenoic acid (DHA), compared to placebo (PL) on RET-induced adaptations following a 10-week RET program (3 days·week−1). Body composition was measured by dual- energy x-ray absorptiometry (LBM, fat mass [FM], percent body fat [%BF]) and strength was measured by 1-repetition maximum bar-bell back squat (1RMSQT) and bench press (1RMBP) at PRE (week 0) and POST (10 weeks). Supplement compliance was assessed via self-report and bottle collection every two weeks and via fatty acid dried blood spot collection at PRE and POST. An a priori α- level of 0.05 was used to determine statistical significance and Cohen’s d was used to quantify effect sizes (ES). Results: Twenty-one of 28 male and female participants (FOS, n = 10 [4 withdrawals]; PL, n = 11 [3 withdrawals]) completed the 10- week progressive RET program and PRE/POST measurements. After 10-weeks, blood EPA+DHA substantially increased in the FOS group (+109.7%, p\u3c .001) and did not change in the PL group (+1.3%, p = .938). Similar between-group changes in LBM (FOS: +3.4%, PL: +2.4%, p = .457), FM (FOS: −5.2%, PL: 0.0%, p = .092), and %BF (FOS: −5.9%, PL: −2.5%, p = .136) were observed, although, the between- group ES was considered large for FM (d = 0.84). Absolute and relative (kg·kg [body mass]−1) 1RMBP was significantly higher in the FOS group compared to PL (FOS: +17.7% vs. PL: +9.7%, p = .047; FOS: +17.6% vs. PL: +7.3%, p = .011; respectively), whereas absolute 1RMSQT was similar between conditions (FOS: +28.8% vs. PL: +20.5%, p = .191). Relative 1RMSQT was higher in the FOS group (FOS: +29.3% vs. PL: +17.9%, p = .045). Conclusions: When combined with RET, FOS improves absolute and relative 1RM upper-body and relative 1RM lower-body strength to a greater extent than that observed in the PL group of young, recreationally trained adults

    Comparison of thermo-hydraulic performance among different 3D printed periodic open cellular structures

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    As additive manufacturing of periodic open cellular structures (POCS) is gaining interest in structured catalytic reactor research, this work seeks to thermohydraulically compare the well-known Kelvin lattice structure with the lesser-researched BCC and gyroid lattice structures. Using a combined CFD (Computational Fluid Dynamic) and experimental approach, the selected POCS are fabricated through Laser Powder Bed Fusion (LPBF), characterized, and subsequently subjected to numerical analysis. From the manufacturability point of view, the 3D printed samples closely matched their CAD designs, showing a maximum porosity deviation of 15% below design values. A CFD model, validated through pressure drop experiment, was employed to compare the POCS designs on shared geometric attributes such as specific surface area and porosity. While all structures exhibited comparable performance in term of heat and momentum transfer, our findings suggest that the Gyroid lattice may provide the optimal balance between momentum and heat transfer rates in low-velocity region. Conversely, the BCC configuration may be more favourable at higher velocity. An Ergun-like correlation was also developed and validated for each lattice type, with a Mean Absolute Percentage Error (MAPE) below 10%. Our pressure drop results align quite well with existing literature correlations, showing a MAPE under 20%. Concerning heat transfer, the values forecasted in this research show a reasonable alignment with literature's results, though they tend to be on the lower spectrum.</p

    Novel Respiratory Virus Infections in Children, Brazil

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    Recently discovered respiratory viruses were detected in 19 (9.2%) of 205 nasal swab specimens from children in Brazil with respiratory illnesses. Five each were positive for human metapneumovirus (HMPV) alone and human bocavirus (HBoV) alone, 3 for human coronaviruses (HCoV-HKU1 or -NL63) alone, and 6 for more than 1 recently discovered virus
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