Ionic shortcut currents via manifolds in reverse electrodialysis stacks

Reverse electrodialysis (RED) is a blue energy technology for clean and sustainable electricity harvesting from the mixing entropy of salinity gradients. Recently, many efforts have been devoted to improving the performance of RED units by developing new ion-exchange membranes and by reducing the detrimental phenomena affecting the process. Among these sources of “irreversibility”, the shortcut currents (or parasitic currents) flowing through alternative pathways may affect the process efficiency. Although such phenomena occur in several electrochemical processes (e.g. fuel cells, bipolar plate cells and vanadium redox flow batteries), they have received a poor attention in RED units. In this work, a process simulator with distributed parameters was developed and experimentally validated to characterize the shortcut currents and to assess their impact in RED stack performance under different designs and operating conditions. Results showed that shortcut currents can play a crucial role in stacks with a large number of cell pairs when the electrical resistance of the parasitic pathways is relatively low, e.g. configurations with concentrated brines, high resistance membranes, short channels or large manifolds. Future designs of efficient industrial-scale units cannot ignore these aspects. Finally, the model can be easily adapted for the simulation of electrodialysis and other electromembrane processes

Is kinesiophobia a predictor of early functional performance after total hip replacement? A prospective prognostic cohort study

Background: Considerable attention has been paid to the role of kinesiophobia with respect to knee prosthesis but it has not yet been studied as a prognostic factor of short-term functional performance following total hip replacement. The main purpose of the present study is to examine the possible predictors of early functional performance of patients undergoing total primary hip arthroplasty, including demographics as age, sex and body mass index, preoperative functional ability, type of anaesthesia, level of haemoglobin, pain and level of kinesiophobia before surgery. Secondly, we want to describe the main characteristics of the population with the highest levels of kinesiophobia. Methods: A prospective, prognostic cohort study was carried out. Patients undergoing primary hip replacement were recruited consecutively. The main outcome is the early functional performance achieved by patients after surgery and measured using the Iowa Level of Assistance (ILOA) scale on the fifth postoperative day. Preoperative kinesiophobia was measured by the Tampa Scale and the preoperative functional ability by the Western Ontario and McMaster Osteoarthritis Index (WOMAC). The multivariate analysis was performed by the General Linear Model. The analysis of the population with high levels of kinesiophobia was conducted by identifying a cut-off of 40 compared to the Tampa Scale. Results: Statistical analysis was performed on 269 patients. The average ILOA score recorded was 19.5 (DS 8.3). The levels of kinesiophobia, showed an average score of 35.1 (7.8) and it was not associated with early functional performance. The independent predictive factors include age, sex and body mass index. Kinesiophobia high levels were recorded in 30% of the population and this population had a higher level of pre-operative WOMAC score. Conclusions: Early functional performance after hip replacement surgery was not correlated with the level of kinesiophobia. Three significant factors that describe a population most at risk of not achieving optimal functional performance are increased age, being female and increase in body mass index. In the preoperative phase, high levels of kinesiophobia were associated with more impaired preoperative functional ability. Trial registration: Current Controlled Trials NCT02786121, May 2016. Retrospectively registered

Smartphone and social network addiction in early adolescents: The role of self-regulatory self-efficacy in a pilot school-based intervention

Background: Youths' online problematic behaviors, such as smartphone or social network sites (SNS) addiction, gained increasing attention nowadays, due to their impact on concurrent and later adjustment, such as emotional and/or behavioral problems, academic impairments, or relational issues. Aims: This study aims to evaluate the effectiveness of a pilot school-based intervention to contrast online addictive behaviors while fostering adolescents' self-regulative abilities. Materials & Methods: The intervention started in January 2022 in an Italian junior high school located in Rome, and consisted of four meetings with students. A total sample of 462 15-year-old adolescents (Mage = 15.2; SD = 0.50; 41% females; Ncontrol = 214; Nintervention = 248) was considered. Within the latent difference score framework, we examined short-term changes from the pre-to-the-postintervention levels of SNS and smartphone addiction, and self-regulatory self-efficacy (SRSE) beliefs as a possible booster of the intervention's effectiveness. Results: Results showed a significant decrease in both online addictions (SNS and smartphone addiction), controlling for age, gender, sexual orientation, and socioeconomic status, because of the short-term efficacy of the project. The buffering effect of SRSE beliefs was further supported. Conclusion: These findings emphasized the usefulness of promoting youths' self-regulative beliefs to contrast problematic tendencies, according to a Positive Youth Development perspective which focused on resources rather than only on the prevention of negative outcomes for youths' adjustment

Acupuncture as an alternative or in addition to conventional treatment for chronic non-specific low back pain: Systematic review and meta-analysis

Background: Conventional therapies (CTs), pharmacological (PH) and non–pharmacological (NPH), do not always achieve benefits in the treatment of chronic low back pain (CLBP). We assessed efficacy and safety of acupuncture for CLBP as alternative or addition to CT. Methods: We included randomised controlled trials (RCTs) comparing acupuncture alone or in combination with CT to CT. We searched Medline, Cochrane Library, Embase up to May 2022. We assessed risk of bias with the original Cochrane tool and GRADE certainty of evidence. Results were pooled through meta-analysis. Results: Ten RCTs (2122 participants) were included comparing acupuncture versus CT and 6 (374 participants) comparing acupuncture plus CT to CT alone. Comparing acupuncture with NPH or PH, no differences were found for pain and disability. Comparing with combined PH and NPH, pain and disability were reduced (SMD=-0.50, 95%CI-0.62 to -0.37; SMD=-0.71, 95%CI-1.17 to -0.24). Comparing acupuncture plus NPH with NPH alone, pain and disability were reduced (SMD=-0.70, 95%CI-0.94 to -0.46; SMD=-0.95, 95%CI-1.36 to -0.54). Comparing acupuncture plus PH with PH alone, pain and disability were reduced (MD=-0.21,8 95%CI-433.28 to -10.42; MD=-3.1, 95%CI-4.87 to -1.83). Comparing acupuncture plus combined treatment versus combined treatment alone, no differences were found in pain, while disability was reduced (MD=-3.40 95%CI-5.17 to -1.63). No studies assessed adverse event. Certainty of evidence ranged from moderate to very low. Conclusion: We are uncertain whether acupuncture is more effective and safer than CT. In the comparisons without estimates’ imprecision, acupuncture showed promising results. Acupuncture could be an option based on patients’ preferences

Efecto de la deformación por tracción uniaxial sobre la fisuración y rugosidad de recubrimientos galvanneal

El “galvanneal” es un recubrimiento de compuestos intermetálicos de hierro y cinc, que se forma cuando una chapa de acero galvanizado es sometida a un recocido, permitiendo que, por difusión, el hierro del sustrato de acero forme una aleación con el cinc del recubrimiento. El resultado es un recubrimiento formado por capas de compuestos intermetálicos de aproximadamente 90% de cinc y 10% de hierro. A finales de los años 70’s, se empezó a utilizar chapa de acero galvanizado para la carrocería de los automóviles a fin de contrarrestar los efectos de la corrosión. Debido a que la resistencia a la corrosión, la pintabilidad y la factibilidad de realizar soldaduras por puntos (tipo de soldadura de mayor uso en la carrocería de los automóviles), son parámetros importantes en la fabricación y desempeño de la carrocería de un automóvil, el “galvanneal” ha ido ganando terreno en esta industria gracias a que puede fabricarse a bajo costo en líneas de galvanizado continuas. El “galvanneal” actualmente es utilizado en el 70% de los automóviles fabricados en Norte América y en China, y prácticamente en el 100% de los automóviles fabricados en Japón. El “galvanneal” tiene una apariencia mate uniforme, a diferencia del galvanizado, que es de apariencia brillante y se pueden observar los macrogranos de cinc incluso después de ser pintado. A escala microscópica, la superficie del “galvanneal” posee fisuras, lo cual resulta en una buena adhesión entre la pintura y el recubrimiento, permitiendo ser pintado sin necesidad de ningún tratamiento previo. El recubrimiento de “galvanneal” presenta mayor resistencia eléctrica, mayor dureza y mayor punto de fusión respecto al galvanizado, lo que permite obtener una soldadura por punto a menor intensidad de corriente y mayor duración de los electrodos.Publicado en Terceras Jornadas de Investigación, Transferencia y Extensión. La Plata : Universidad Nacional de La Plata, 2015.Facultad de Ingenierí

Efecto de la deformación por tracción uniaxial sobre la fisuración y rugosidad de recubrimientos galvanneal

El “galvanneal” es un recubrimiento de compuestos intermetálicos de hierro y cinc, que se forma cuando una chapa de acero galvanizado es sometida a un recocido, permitiendo que, por difusión, el hierro del sustrato de acero forme una aleación con el cinc del recubrimiento. El resultado es un recubrimiento formado por capas de compuestos intermetálicos de aproximadamente 90% de cinc y 10% de hierro. A finales de los años 70’s, se empezó a utilizar chapa de acero galvanizado para la carrocería de los automóviles a fin de contrarrestar los efectos de la corrosión. Debido a que la resistencia a la corrosión, la pintabilidad y la factibilidad de realizar soldaduras por puntos (tipo de soldadura de mayor uso en la carrocería de los automóviles), son parámetros importantes en la fabricación y desempeño de la carrocería de un automóvil, el “galvanneal” ha ido ganando terreno en esta industria gracias a que puede fabricarse a bajo costo en líneas de galvanizado continuas. El “galvanneal” actualmente es utilizado en el 70% de los automóviles fabricados en Norte América y en China, y prácticamente en el 100% de los automóviles fabricados en Japón. El “galvanneal” tiene una apariencia mate uniforme, a diferencia del galvanizado, que es de apariencia brillante y se pueden observar los macrogranos de cinc incluso después de ser pintado. A escala microscópica, la superficie del “galvanneal” posee fisuras, lo cual resulta en una buena adhesión entre la pintura y el recubrimiento, permitiendo ser pintado sin necesidad de ningún tratamiento previo. El recubrimiento de “galvanneal” presenta mayor resistencia eléctrica, mayor dureza y mayor punto de fusión respecto al galvanizado, lo que permite obtener una soldadura por punto a menor intensidad de corriente y mayor duración de los electrodos.Publicado en Terceras Jornadas de Investigación, Transferencia y Extensión. La Plata : Universidad Nacional de La Plata, 2015.Facultad de Ingenierí

Efecto de la deformación por tracción uniaxial sobre la fisuración y rugosidad de recubrimientos galvanneal

El “galvanneal” es un recubrimiento de compuestos intermetálicos de hierro y cinc, que se forma cuando una chapa de acero galvanizado es sometida a un recocido, permitiendo que, por difusión, el hierro del sustrato de acero forme una aleación con el cinc del recubrimiento. El resultado es un recubrimiento formado por capas de compuestos intermetálicos de aproximadamente 90% de cinc y 10% de hierro. A finales de los años 70’s, se empezó a utilizar chapa de acero galvanizado para la carrocería de los automóviles a fin de contrarrestar los efectos de la corrosión. Debido a que la resistencia a la corrosión, la pintabilidad y la factibilidad de realizar soldaduras por puntos (tipo de soldadura de mayor uso en la carrocería de los automóviles), son parámetros importantes en la fabricación y desempeño de la carrocería de un automóvil, el “galvanneal” ha ido ganando terreno en esta industria gracias a que puede fabricarse a bajo costo en líneas de galvanizado continuas. El “galvanneal” actualmente es utilizado en el 70% de los automóviles fabricados en Norte América y en China, y prácticamente en el 100% de los automóviles fabricados en Japón. El “galvanneal” tiene una apariencia mate uniforme, a diferencia del galvanizado, que es de apariencia brillante y se pueden observar los macrogranos de cinc incluso después de ser pintado. A escala microscópica, la superficie del “galvanneal” posee fisuras, lo cual resulta en una buena adhesión entre la pintura y el recubrimiento, permitiendo ser pintado sin necesidad de ningún tratamiento previo. El recubrimiento de “galvanneal” presenta mayor resistencia eléctrica, mayor dureza y mayor punto de fusión respecto al galvanizado, lo que permite obtener una soldadura por punto a menor intensidad de corriente y mayor duración de los electrodos.Publicado en Terceras Jornadas de Investigación, Transferencia y Extensión. La Plata : Universidad Nacional de La Plata, 2015.Facultad de Ingenierí

Fingerprinting of hydroxyl radical-attacked polysaccharides by N-isopropyl-2-aminoacridone labelling

Hydroxyl radicals ((•)OH) cause non-enzymic scission of polysaccharides in diverse biological systems. Such reactions can be detrimental (e.g. causing rheumatic and arthritic diseases in mammals) or beneficial (e.g. promoting the softening of ripening fruit, and biomass saccharification). Here we present a method for documenting (•)OH action, based on fluorescent labelling of the oxo groups that are introduced as glycosulose residues when (•)OH attacks polysaccharides. The method was tested on several polysaccharides, especially pectin, after treatment with Fenton reagents. 2-Aminoacridone plus cyanoborohydride reductively aminated the oxo groups in treated polysaccharides; the product was then reacted with acetone plus cyanoborohydride, forming a stable tertiary amine with the carbohydrate linked to N-isopropyl-2-aminoacridone (pAMAC). Digestion of labelled pectin with ‘Driselase’ yielded several fluorescent products which on electrophoresis and HPLC provided a useful ‘fingerprint’ indicating (•)OH attack. The most diagnostic product was a disaccharide conjugate of the type pAMAC·UA-GalA (UA=unspecified uronic acid), whose UA-GalA bond was Driselase-resistant (product 2A). 2A was clearly distinguishable from GalA-GalA–pAMAC (disaccharide labelled at its reducing end), which was digestible to GalA–pAMAC. The methodology is applicable, with appropriate enzymes in place of Driselase, for detecting natural and artificial (•)OH attack in diverse plant, animal and microbial polysaccharides

Effective recovery of HCl and metals from pickling solutions by cutting-edge membrane technologies

The pickling process is an essential step in the hot-dip galvanizing process.It is performed by immersing manufacturedsteel pieces inacid bathsin order todissolve the oxidized layers. During the pickling process, acid attacks metal oxides on the surface, dissolving them in the pickling bath. Thus, the efficiency of the pickling liquor decreases due to the accumulation of metal salts and the consumption of free acid in the solution. When hydrochloric acid is used,ferrous chloride is producedduring the pickling treatment, reaching concentrations up to 250 g/l, while the acid concentration decreases by 75-85%. A pickling bath in this condition is considered spent [1] due to thevery low picklingrate, hence it needs to be replaced. In common industrial practice,part of the exhausted solution is withdrawn and replaced with fresh acid orwitha more concentrate solution to prolong the pickling bath life, while spentsolution is disposed asa waste.Disposal of the spentpickling solution strongly affects the hot-dip galvanizing industries footprintand costs, thus the recovery of acid is one of the most beneficial steps to reduce the environmental and economic impact.In particular, continuous regeneration of pickling solutions can enhance pickling rate and process performance, butalso reduce industrial wastewater disposal and chemicals consumption. The recovery and recycling of valuable compounds (e.g. acid, metals and water) can be accomplished by coupling two cutting-edge membrane technologies: diffusion dialysis (DD) and membrane distillation (MD) [2,3]. Membrane techniques are considered simple, effective and sustainable [1]and can be easily scaled from small to medium side installations.In the present work, a case study is presented, relevant tothe hot-dip galvanizing plant of TecnoZinco(Palermo, Italy).The site has a capacity of 20,000 tons per yearof treated steel. Starting from an accurate data mining, a Process Flow Diagram(PFD)of an integrated process that provides a continuous regeneration of pickling solution is proposed, within the framework of the EU-funded ReWaCEM project(www.rewacem.eu), with the final aim of buildinga pilot plant to be installedand operated in real environment. Asteady state process simulator for the integrated process has been developed, aiming to design, analyze and predict performance of the pilot unit. A parametric analysis of the model is performed varying hydrochloric acid in the stream going out from the pickling tank. Results presents the perspective operation of such plant, indicating the technical feasibility of the novel developed process

On the modelling of an Acid/Base Flow Battery: An innovative electrical energy storage device based on pH and salinity gradients

Electrical energy storage can enhance the efficiency in the use of fluctuating renewable sources, e.g. solar and wind energy. The Acid/Base Flow Battery is an innovative and sustainable process to store electrical energy in the form of pH and salinity gradients via electrodialytic reversible techniques. Two electromembrane processes are involved: Bipolar Membrane Electrodialysis during the charge phase and its opposite, Bipolar Membrane Reverse Electrodialysis, during the discharge phase. For the first time, the present work aims at predicting the performance of this energy storage device via the development of a dynamic mathematical model based on a multi-scale approach with distributed parameters. Four models, each one at a different scale, are fully integrated in a comprehensive process simulator. The model was preliminary validated by a comparison with experimental data and a good agreement was found. A sensitivity analysis was performed to identify the most detrimental phenomena. Results indicate a loss of 25–35% of Round Trip Efficiency caused by parasitic currents in the manifolds. Therefore, they may represent the main limit to the present technology performance in scaled-up stacks converting more power. Suitable geometries and operating conditions should be adopted to tackle this issue (e.g. isolated blocks), thus enhancing the battery Round Trip Efficiency