420 research outputs found

    A novel ionic exchange membrane crystallizer to recover magnesium hydroxide from seawater and industrial brines

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    A novel technology, the ion exchange membrane crystallizer (CrIEM), that combines reactive and membrane crystallization, was investigated in order to recover high purity magnesium hydroxide from multi-component artificial and natural solutions. In particular, in a CrIEM reactor, the presence of an anion exchange membrane (AEM), which separates two-compartment containing a saline solution and an alkaline solution, allows the passage of hydroxyl ions from the alkaline to the saline solution compartment, where crystallization of magnesium hydroxide occurs, yet avoiding a direct mixing between the solutions feeding the reactor. This enables the use of low-cost reactants (e.g., Ca(OH)2) without the risk of co-precipitation of by-products and contamination of the final crystals. An experimental campaign was carried out treating two types of feed solution, namely: (1) a waste industrial brine from the Boles\u142aw \u15amia\u142y coal mine in \u141aziska G\uf3rne (Poland) and (2) Mediterranean seawater, collected from the North Sicilian coast (Italy). The CrIEM was tested in a feed and bleed modality in order to operate in a continuous mode. The Mg2+ concentration in the feed solutions ranges from 0.7 to 3.2 g/L. Magnesium recovery efficiencies from 89 up to 100% were reached, while magnesium hydroxide purity between 94% and 98.8% was obtained

    Impact of counter-bore nozzle on the combustion process and exhaust emissions for light-duty diesel engine application

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    This is the author s version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087418819250[EN] This article describes the main results of an investigation about counter-bore injector nozzle impact on the combustion process in a modern Euro 6 diesel engine. First, hydraulic and spray visualization tests have been performed, showing a potential advantage of such nozzle design in fuel-air mixing efficiency. Then, combustion performance has been assessed on a GM-designed 1.6-L four-cylinder engine. The engine has been installed on a dynamometric test bench and instrumented with an AVL cylinder pressure transducer for heat release rate analysis, as well as HORIBA MEXA gas analyzer for exhaust emissions and AVL 415 Smoke Meter. Engine efficiency and emissions have been analyzed on four different part-load steady-state points, representative of New European Driving Cycle and Worldwide harmonized Light duty Test Cycle certification cycles, and covering engine speeds from 1250 to 2000 r/min and brake mean effective pressure between 0.2 and 1.4 MPa. Results of indicated analysis show that counter-bore nozzles have significant differences in terms of pilot injection combustion at low load points, which in turn lead to a better ignition and shorter combustion of the main injection. In addition, an improvement of diffusive combustion is observed as load increases. Because of both, fuel consumption is reduced by approximately 1% with respect to a standard nozzle. Finally, an appreciable decrease in engine exhaust emissions has been recorded, especially in terms of particulate matter and hydrocarbon emissions. This reduction has been linked to the improvement of fuel-air mixing promoted by the counter-bore nozzle previously observed.The authors would like to thank General Motors Global Propulsion Systems-Torino S.r.l. for sponsoring the current work. Part of the equipment was purchased with the help of Generalitat Valenciana in project IDIFEDER2018 with title "Equipamiento de diagnostico optico de alta velocidad para estudiar procesos de inyeccion''.Payri, R.; De La Morena, J.; Monsalve-Serrano, J.; Pesce, FC.; Vassallo, A. (2019). Impact of counter-bore nozzle on the combustion process and exhaust emissions for light-duty diesel engine application. International Journal of Engine Research. 20(1):46-57. https://doi.org/10.1177/1468087418819250S4657201Kastengren, A. L., Tilocco, F. Z., Powell, C. F., Manin, J., Pickett, L. M., Payri, R., & Bazyn, T. (2012). ENGINE COMBUSTION NETWORK (ECN): MEASUREMENTS OF NOZZLE GEOMETRY AND HYDRAULIC BEHAVIOR. Atomization and Sprays, 22(12), 1011-1052. doi:10.1615/atomizspr.2013006309Payri, R., Viera, J. P., Gopalakrishnan, V., & Szymkowicz, P. G. (2016). The effect of nozzle geometry over internal flow and spray formation for three different fuels. Fuel, 183, 20-33. doi:10.1016/j.fuel.2016.06.041Postrioti, L., Malaguti, S., Bosi, M., Buitoni, G., Piccinini, S., & Bagli, G. (2014). Experimental and numerical characterization of a direct solenoid actuation injector for Diesel engine applications. Fuel, 118, 316-328. doi:10.1016/j.fuel.2013.11.001Payri, R., Gimeno, J., De la Morena, J., Battiston, P. A., Wadhwa, A., & Straub, R. (2016). Study of new prototype pintle injectors for diesel engine application. Energy Conversion and Management, 122, 419-427. doi:10.1016/j.enconman.2016.06.003Payri, R., Bracho, G., Marti-Aldaravi, P., & Viera, A. (2017). NEAR FIELD VISUALIZATION OF DIESEL SPRAY FOR DIFFERENT NOZZLE INCLINATION ANGLES IN NON-VAPORIZING CONDITIONS. Atomization and Sprays, 27(3), 251-267. doi:10.1615/atomizspr.2017017949Li, T., Moon, S., Sato, K., & Yokohata, H. (2017). A comprehensive study on the factors affecting near-nozzle spray dynamics of multi-hole GDI injectors. Fuel, 190, 292-302. doi:10.1016/j.fuel.2016.11.009Payri, R., Viera, J. P., Gopalakrishnan, V., & Szymkowicz, P. G. (2017). The effect of nozzle geometry over ignition delay and flame lift-off of reacting direct-injection sprays for three different fuels. Fuel, 199, 76-90. doi:10.1016/j.fuel.2017.02.075Yao, C., Geng, P., Yin, Z., Hu, J., Chen, D., & Ju, Y. (2016). Impacts of nozzle geometry on spray combustion of high pressure common rail injectors in a constant volume combustion chamber. Fuel, 179, 235-245. doi:10.1016/j.fuel.2016.03.097Hong, J. G., Ku, K. W., Kim, S. R., & Lee, C. W. (2010). EFFECT OF CAVITATION IN CIRCULAR NOZZLE AND ELLIPTICAL NOZZLES ON THE SPRAY CHARACTERISTIC. Atomization and Sprays, 20(10), 877-886. doi:10.1615/atomizspr.v20.i10.40Molina, S., Salvador, F. J., Carreres, M., & Jaramillo, D. (2014). A computational investigation on the influence of the use of elliptical orifices on the inner nozzle flow and cavitation development in diesel injector nozzles. Energy Conversion and Management, 79, 114-127. doi:10.1016/j.enconman.2013.12.015Taskiran, O. O., & Ergeneman, M. (2014). Effect of nozzle dimensions and fuel type on flame lift-off length. Fuel, 115, 833-840. doi:10.1016/j.fuel.2013.03.005He, Z., Guo, G., Tao, X., Zhong, W., Leng, X., & Wang, Q. (2016). Study of the effect of nozzle hole shape on internal flow and spray characteristics. International Communications in Heat and Mass Transfer, 71, 1-8. doi:10.1016/j.icheatmasstransfer.2015.12.002Salvador, F. J., de la Morena, J., Carreres, M., & Jaramillo, D. (2017). Numerical analysis of flow characteristics in diesel injector nozzles with convergent-divergent orifices. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 231(14), 1935-1944. doi:10.1177/0954407017692220Baldwin, E. T., Grover, R. O., Parrish, S. E., Duke, D. J., Matusik, K. E., Powell, C. F., … Schmidt, D. P. (2016). String flash-boiling in gasoline direct injection simulations with transient needle motion. International Journal of Multiphase Flow, 87, 90-101. doi:10.1016/j.ijmultiphaseflow.2016.09.004Payri, R., Salvador, F. J., Gimeno, J., & Bracho, G. (2008). A NEW METHODOLOGY FOR CORRECTING THE SIGNAL CUMULATIVE PHENOMENON ON INJECTION RATE MEASUREMENTS. Experimental Techniques, 32(1), 46-49. doi:10.1111/j.1747-1567.2007.00188.xDesantes, J. M., Pastor, J. V., García-Oliver, J. M., & Pastor, J. M. (2009). A 1D model for the description of mixing-controlled reacting diesel sprays. Combustion and Flame, 156(1), 234-249. doi:10.1016/j.combustflame.2008.10.008PASTOR, J., JAVIERLOPEZ, J., GARCIA, J., & PASTOR, J. (2008). A 1D model for the description of mixing-controlled inert diesel sprays. Fuel, 87(13-14), 2871-2885. doi:10.1016/j.fuel.2008.04.017Payri, F., Molina, S., Martín, J., & Armas, O. (2006). Influence of measurement errors and estimated parameters on combustion diagnosis. Applied Thermal Engineering, 26(2-3), 226-236. doi:10.1016/j.applthermaleng.2005.05.00

    A pilot-plant for the selective recovery of magnesium and calcium from waste brines

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    The problem of brines disposal has raised great interest towards new strategies for their valorisation through the recovery of minerals or energy. As an example, the spent brine from ion exchange resins regeneration is often discharged into rivers or lakes, thus impacting on the process sustainability. However, such brines can be effectively reconcentrated, after removal of bivalent cations, and reused for the resins regeneration. This work focuses on developing and testing a pilot plant for selective recovery of magnesium and calcium from spent brines exploiting a novel proprietary crystallization unit. This is part of a larger treatment chain for the complete regeneration of the brine, developed within the EU-funded ZERO BRINE project. The pilot crystallizer was tested with the retentate of the nanofiltration unit processing the spent brine from the industrial water production plant of Evides Industriewater B.V. (Rotterdam, The Netherlands). Magnesium and calcium hydroxide were selectively precipitated by adding alkaline solution in two consecutive steps and controlling reaction pH. Performance was assessed in terms of recovery efficiency and purity of produced crystals, observing in most investigated cases a recovery of about 100% and 97% and a purity above 90% and 96%, for magnesium and calcium hydroxide, respectively

    Hyaluronan and Derivatives: An In Vitro Multilevel Assessment of Their Potential in Viscosupplementation

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    In this research work, viscosupplements based on linear, derivatized, crosslinked and complexed HA forms were extensively examined, providing data on the hydrodynamic parameters for the water-soluble-HA-fraction, rheology, sensitivity to enzymatic hydrolysis and capacity to modulate specific biomarkers’ expression in human pathological chondrocytes and synoviocytes. Soluble HA ranged from 0 to 32 mg/mL and from 150 to 1330 kDa MW. The rheological behavior spanned from purely elastic to viscoelastic, suggesting the diversity of the categories that are suitable for restoring specific/different features of the healthy synovial fluid. The rheological parameters were reduced in a diverse manner upon dilution and hyaluronidases action, indicating different durations of the viscosupplementation effect. Bioactivity was found for all the samples, increasing the expression of different matrix markers (e.g., hyaluronan-synthase); however, the hybrid cooperative complexes performed better in most of the experiments. Hybrid cooperative complexes improved COLII mRNA expression (~12-fold increase vs. CTR), proved the most effective at preserving cell phenotype. In addition, in these models, the HA samples reduced inflammation. IL-6 was down-regulated vs. CTR by linear and chemically modified HA, and especially by hybrid complexes. The results represent the first comprehensive panel of data directly comparing the diverse HA forms for intra-articular injections and provide valuable information for tailoring products’ clinical use as well as for designing new, highly performing HA-formulations that can address specific needs

    Validation of the Italian version of the Devaluation consumers' Scale and the Devaluation Consumers Families Scale

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    Objectives: This study aimed to assess the psychometric properties of the Italian versions of the Devaluation of Consumers Scale (DCS) and the Devaluation of Consumer Families Scale (DCFS), two short-scales examining public stigma towards people with mental disorders and their relatives. Methods: The scales were administered to 117 individuals with a clinical diagnosis of affective or non-affective psychoses (ICD 10 criteria F20-29, F30-33). Translation procedures were carried out according to accepted standards. Internal reliability was assessed using Cronbach's alpha coefficient. Convergent validity was evaluated in terms of correlation with the Global Functioning Scale (GAF) and with the Questionnaire on Users' Opinions (QUO). Known-group validity was assessed comparing patients at first-episode of psychosis and patients with a history of psychosis of at least 3 years (long-term psychosis). Results: The overall Cronbach's alpha value was 0.85 for DCS and 0.81 for DCFS; subscales' alpha values ranged from 0.80 to 0.55 for DCS, and from 0.68 to 0.55 for DCFS. Negative correlations were found between the Italian DCS and the DCFS total score and the QUO affective problems (DCS -0.33; DCFS -0.235) and social distance subscales (DCS -0.290; DCFS -0.356). Moreover, the GAF positively correlated with some of the DCS and DCFS subscales. Patients with long-term psychosis had higher scores in most DCS and DCFS subscales. Conclusion: The Italian translation of DCF and DCFS showed good internal consistency, known-group validity, and convergent validity. These psychometric properties support their application in routine clinical practice in Italy as well as their use in international studies

    An epidemic model for COVID-19 transmission in Argentina: Exploration of the alternating quarantine and massive testing strategies

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    The COVID-19 pandemic has challenged authorities at different levels of government administration aroundthe globe. When faced with diseases of this severity, it is useful for the authorities to have prediction tools to estimate in advance the impact on the health system as well as the human, material, and economic resources that will be necessary. In this paper, we construct an extended Susceptible?Exposed?Infected?Recovered modelthat incorporates the social structure of Mar del Plata, the 4◦ most inhabited city in Argentina and head ofthe Municipality of General Pueyrredón. Moreover, we consider detailed partitions of infected individualsaccording to the illness severity, as well as data of local health resources, to bring predictions closer to thelocal reality. Tuning the corresponding epidemic parameters for COVID-19, we study an alternating quarantinestrategy: a part of the population can circulate without restrictions at any time, while the rest is equally dividedinto two groups and goes on successive periods of normal activity and lockdown, each one with a durationof days. We also implement a random testing strategy with a threshold over the population. We found that = 7 is a good choice for the quarantine strategy since it reduces the infected population and, conveniently,it suits a weekly schedule. Focusing on the health system, projecting from the situation as of September 30,we foresee a difficulty to avoid saturation of the available ICU, given the extremely low levels of mobility thatwould be required. In the worst case, our model estimates that four thousand deaths would occur, of which30% could be avoided with proper medical attention. Nonetheless, we found that aggressive testing wouldallow an increase in the percentage of people that can circulate without restrictions, and the medical facilitiesto deal with the additional critical patients would be relatively low.Fil: Vassallo, Lautaro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Pérez, Ignacio Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Alvarez Zuzek, Lucila G.. University Of Georgetown; Estados UnidosFil: Amaya, Julián. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Física; ArgentinaFil: Torres, Marcos F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Valdez, Lucas Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: la Rocca, Cristian Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Braunstein, Lidia Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin

    Sistematización de experiencias de desarrollo rural con enfoque territorial en los departamentos de Montevideo, Paysandú y Tacuarembó

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    El objetivo general de este estudio es el de efectuar un relevamiento y selección de las experiencias de desarrollo rural en los Departamentos de Tacuarembó, Paysandú y Montevideo, entre los años 1985 y 2005, y sistematizar las más relevantes desde una perspectiva que tome en cuenta el enfoque territoria

    Hyaluronan-Based Gel Promotes Human Dental Pulp Stem Cells Bone Differentiation by Activating YAP/TAZ Pathway.

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    Background: Hyaluronans exist in different forms, accordingly with molecular weight and degree of crosslinking. Here, we tested the capability to induce osteogenic differentiation in hDPSCs (human dental pulp stem cells) of three hyaluronans forms: linear pharmaceutical-grade hyaluronans at high and (HHA) low molecular weight (LHA) and hybrid cooperative complexes (HCC), containing both sizes. Methods: hDPSCs were treated with HHA, LHA, HCC for 7, 14 and 21 days. The effects of hyaluronans on osteogenic differentiation were evaluated by qRT-PCR and WB of osteogenic markers and by Alizarin Red S staining. To identify the involved pathway, CD44 was analyzed by immunofluorescence, and YAP/TAZ expression was measured by qRT-PCR. Moreover, YAP/TAZ inhibitor-1 was used, and the loss of function of YAP/TAZ was evaluated by qRT-PCR, WB and immunofluorescence. Results: We showed that all hyaluronans improves osteogenesis. Among these, HCC is the main inducer of osteogenesis, along with overexpression of bone related markers and upregulating CD44. We also found that this biological process is subordinate to the activation of YAP/TAZ pathway. Conclusions: We found that HA's molecular weight can have a relevant impact on HA performance for bone regeneration, and we unveil a new molecular mechanism by which HA acts on stem cells. Keywords: YAP/TAZ pathway; dental pulp stem cells; hyaluronic acid; osteogenic differentiation

    The key neuroendocrine regulators of the onset of puberty in the Atlantic bluefin tuna (Thunnus thynnus)

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    Recently, significant progress on spawning induction in captive bluefin tuna (BFT, Thunnus thynnus), has been achieved providing the basis for the species' domestication. To further promote the development of a self- sustained BFT aquaculture, we investigated first sexual maturity in BFT reared from an immature stage in captivity. Accordingly, our major objectives were to evaluate: (i) maturational status of the brain-pituitary-gonadal (BPG) axis, and (ii) responsiveness of the BPG to exogenous hormones. Special emphasis was given to characterize the gonadotropins follicle stimulating hormone (FSH) and luteinizing hormone (LH) that act as central regulators of gonadal development and gamete maturation. The growth parameters recorded for the captive BFT juveniles are consistent with the length-weight relationship established for wild Mediterranean BFT stocks. The histological analyses of the gonads indicate advanced sexual maturation in BFT males compared to females, yet it is not yet clear whether this phenomenon typifies wild stocks or is induced due to the culture conditions. The hormone measurements show expression and accumulation of both gonadotropins in the pituitaries of immature and mature BFT. The pituitary LH content increased concomitantly with the age of the fish, exhibiting sex dimorphic patterns (i.e. 3-fold higher levels in females) in adult but not in juvenile BFT. The pituitary FSH levels, however, were elevated in 2Y immature males and in fully mature adults. Comparable to mammals, the intra-pituitary FSH/LH ratio was found to be higher (>1) in sexually immature than in maturing or pubertal BFT. Nevertheless, in the 3Y BFT females, which were all immature, the onset of puberty appears to require some other prerequisites, such as a rise in the LH storage above a minimal threshold. Our in vitro trials further demonstrated the capacity of rFSH and to a lesser extent that of rLH to stimulate cell proliferation in the immature ovarian and testicular fragments. Both rFSH and rLH have failed to stimulate steroidogenesis, yet pre-treatment with KiSS containing EVAc implants appeared to potentiate FSH-stimulated steroidogenesis in the immature testes. On the other hand, the expression levels of both the GtH-R and IGF I genes in the testicular fragments, derived from BFT juveniles and further exposed to the rLH treatment, showed dose-dependent pattern. Future studies testing the effects of captivity and hormone-based treatments on precocious maturity at relatively small body size are expected to facilitate the handling in confined environments, and to greatly improve the cost-efficiency of BFT farming.Postprin
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