Sustainable and renewable hydrogen production from recycled aluminum

The whole world has been suffering strong consequences related to climate change. The intense use of fossil fuels in the chemical and automotive industries have put the environment in jeopardy. Thus, the industry has achieved a point of no return and it is urgent the development of renewable and sustainable technologies. Hydrogen has been pointed as a key component of the new era in industry since it can be produced in a clean and sustainable way. Currently the development of hydrogen fuel cells technology has put the automotive sector ahead of the chemical industries in relation to studies regarding the hydrogen production. Chemical industries produce hydrogen with technologies reliant on fossil fuels while the automotive sector has been looking for renewable forms of hydrogen generation.  Trains powered by hydrogen fuel cells are a reality in Europe, for instance. Hydrogen generation technological advances must match the pace of the development of fuel cells electrical vehicles in order to the environmental goals and widespread application of fuel cell systems to be achieved.  The present study addresses the hydrogen generation from the spontaneous reaction between aluminum and aqueous solution of sodium hydroxide. Aluminum is a metal that presents high exergetic value and can be recycled several times without losing its thermo-mechanical properties. That makes the use of aluminum especially appealing. It will make hydrogen generation a cleaner and more affordable process.  Our findings demonstrate that it is possible to predict the kinetic behavior of the reaction using data obtained by the conductometric method. Graphs of electrical conductivity vs time show that is possible to verify the order of the reaction. We will present concepts of kinetic, thermodynamic and transport phenomena of the reaction between solid recycled aluminum and sodium hydroxide in an aqueous solution.  The knowledge acquired throughout this study will contribute to the development of a new reactor and as a consequence, a new renewable and sustainable industrial system of hydrogen generation

TURBULENT STRESS DISTRIBUTION IN THE TURBULENT BOUNDARY LAYER ON A PERMEABLE POROUS PLATE

In this paper the results of experimental tests on turbulent boundary layer on a plate with air blowing through permeable porous wall are presented. Tests were performed in an aerodynamic tunnel varying the blowing rate within the range of 0 to 2.5% of the air flow velocity in the tunnel, using thermoanemometers of constant temperature. It has been determined that the blowing increases the boundary layer thickness and strongly transforms the boundary layer inner part and turbulent nucleus, while the outer part remains not deformed. An increase in blowing causes an abrupt viscous stress decrease, also decreasing skin friction. Thick boundary layers (up to 120 mm) allowed a profound analysis of Reynolds' turbulent stresses. It has been found a general distribution of turbulent stress in the turbulent layer which is independent of blowing velocity. It has been established for the turbulent characteristics that the determining coordinate is the relative horizontal velocity, not the distance from the wall. With a turbulent stress database obtained from turbulent stresses direct measurements, it has been proposed a flow model for boundary layer on a permeable porous plate. It has also been demonstrated that in high blowing conditions the horizontal velocity profile in the boundary layer becomes equal to the velocity profile in a plane jet

SUSTAINABLE ALKALINE MEMBRANE FUEL CELL

This work proposes a sustainable alkaline membrane fuel cell (SAMFC) comprising a traditional AMFC coupled to a hydrogen generation reactor. The reactor uses recycled aluminum from soda cans to split the water molecule via oxidation catalyzed by NaOH, and an innovative cellulose membrane eliminates the undesirable characteristics of liquid electrolytes and asbestos or ammonia---common constituents of alkaline electrolyte membranes that are toxic and carcinogenic. Oxygen is supplied to the cell by first directing the ambient air through KOH aqueous solution to remove CO2 and thus to avoid the formation of K­2CO3. In this paper, an SAMFC system with one unitary cell, reactor, and CO2 purifier was designed, built, and tested in the laboratory, and the system was compared experimentally against traditional AMFCs driven by commercial hydrogen and by the hydrogen derived from commercial aluminum. According to experimental polarization and power curves, the SAMFC delivered 0.9V in open circuit and approximately 0.42W of maximum power with recycled aluminum. The study thereby demonstrates the economic potential and competitive performance of the proposed SAMFC against traditional fuel cells

OPTIMALLY STAGGERED FINNED CIRCULAR AND ELLIPTIC TUBES IN FORCED CONVECTION

This work presents a three-dimensional (3-D) numerical and experimental geometric optimization study to maximize the total heat transfer rate between a bundle of finned tubes in a given volume and a given external flow both for circular and elliptic arrangements, for general staggered configurations. The optimization procedure started by recognizing the design limited space availability as a fixed volume constraint. The experimental results were obtained for circular and elliptic configurations with a fixed number of tubes (12), starting with an equilateral triangle configuration, which fitted uniformly into the fixed volume with a resulting maximum dimensionless tube-to-tube spacing S/2b = 1.5, where S is the actual spacing and b is the smaller ellipse semi-axis. Several experimental configurations were built by reducing the tube-to-tube spacings, identifying the optimal spacing for maximum heat transfer. Similarly, it was possible to investigate the existence of optima with respect to other two geometric degrees of freedom, i.e., tube eccentricity and fin-to-fin spacing. The results are reported for air as the external fluid in the laminar regime, for 125 and 100 Re 2b , where 2b is the ellipses smaller axis length. Circular and elliptic arrangements with the same flow obstruction cross-sectional area were compared on the basis of maximum total heat transfer. This criterion allows one to quantify the heat transfer gain in the most isolated way possible, by studying arrangements with equivalent total pressure drops independently of the tube cross section shape. This paper reports three-dimensional (3- D) numerical optimization results for finned circular and elliptic tubes arrangements, which are validated by direct comparison with experimental measurements with good agreement. Global optima with respect to tube-to-tube spacing, eccentricity and fin-tofin spacing ( 0.5 e 0.5, S/2b and 06 . 0 f for 125 and 100 Re 2b , respectively) were found and reported in general dimensionless variables. A relative heat transfer gain of up to 19% is observed in the optimal elliptic arrangement, as compared to the optimal circular one. The heat transfer gain, combined with the relative material mass reduction of up to 32% observed in the optimal elliptic arrangement in comparison to the circular one, show the elliptical arrangement has the potential for a considerably better overall performance and lower cost than the traditional circular geometry

Cost utility of a pharmacist‑led minor ailment service compared with usual pharmacist care

Background: A cluster randomised controlled trial (cRCT) performed from July 2018 to March 2019 demonstrated the clinical impact of a community pharmacist delivered minor ailment service (MAS) compared with usual phar‑ macist care (UC). MAS consisted of a technology-based face-to-face consultation delivered by trained community pharmacists. The consultation was guided by clinical pathways for assessment and management, and communica‑ tion systems, collaboratively agreed with general practitioners. MAS pharmacists were trained and provided monthly practice support by a practice change facilitator. The objective of this study was to assess the cost utility of MAS, compared to UC. Methods: Participants recruited were adult patients with symptoms suggestive of a minor ailment condition, from community pharmacies located in Western Sydney. Patients received MAS (intervention) or UC (control) and were followed-up by telephone 14-days following consultation with the pharmacist. A cost utility analysis was conducted alongside the cRCT. Transition probabilities and costs were directly derived from cRCT study data. Utility values were not available from the cRCT, hence we relied on utility values reported in the published literature which were used to calculate quality adjusted life years (QALYs), using the area under the curve method. A decision tree model was used to capture the decision problem, considering a societal perspective and a 14-day time horizon. Deterministic and probabilistic sensitivity analyses assessed robustness and uncertainty of results, respectively. Results: Patients (n=894) were recruited from 30 pharmacies and 82% (n=732) responded to follow-up. On aver‑ age, MAS was more costly but also more efective (in terms of symptom resolution and QALY gains) compared to UC. MAS patients (n=524) gained an additional 0.003 QALYs at an incremental cost of $7.14 (Australian dollars), com‑ pared to UC (n=370) which resulted in an ICER of$2277 (95% CI $681.49–3811.22) per QALY. Conclusion: Economic fndings suggest that implementation of MAS within the Australian context is cost efective. Trial registration Registered with Australian New Zealand Clinical Trials Registry (ANZCTR) and allocated the ACTRN: ACTRN12618000286246. Registered on 23 February 2018.Consumer Healthcare Products AustraliaAustralian Governmen

Reversal of hepatorenal syndrome type 1 with terlipressin plus albumin vs. placebo plus albumin in a pooled analysis of the OT-0401 and REVERSE randomised clinical studies

Background The goal of hepatorenal syndrome type 1 (HRS-1) treatment is to improve renal function. Terlipressin, a synthetic vasopressin analogue, is a systemic vasoconstrictor used for the treatment of HRS-1, where it is available. Aim To compare the efficacy of terlipressin plus albumin vs. placebo plus albumin in patients with HRS-1. Methods Pooled patient-level data from two large phase 3, randomised, placebo-controlled studies were analysed for HRS reversal [serum creatinine (SCr) value ≤133 μmol/L], 90-day survival, need for renal replacement therapy and predictors of HRS reversal. Patients received intravenous terlipressin 1–2 mg every 6 hours plus albumin or placebo plus albumin up to 14 days. Results The pooled analysis comprised 308 patients (terlipressin: n = 153; placebo: n = 155). HRS reversal was significantly more frequent with terlipressin vs. placebo (27% vs. 14%; P = 0.004). Terlipressin was associated with a more significant improvement in renal function from baseline until end of treatment, with a mean between-group difference in SCr concentration of −53.0 μmol/L (P \u3c 0.0001). Lower SCr, lower mean arterial pressure and lower total bilirubin and absence of known precipitating factors for HRS were independent predictors of HRS reversal and longer survival in terlipressin-treated patients. Conclusions Terlipressin plus albumin resulted in a significantly higher rate of HRS reversal vs. albumin alone in patients with HRS-1. Terlipressin treatment is associated with improved renal function

THE HARVESTING OF HIGH LIPID CONTENT MICROALGAE BIOMASS THROUGH A FLOCCULATION STRATEGY

Different flocculants were evaluated for the flocculation of microalgae biomass of Acutodesmus obliquus. Flocculation was tested with FeCl3 and NaOH at different concentrations and compared to a sample centrifuged at 7000 rpm. The evaluated parameters were absorbance (540 nm) in the clarified medium, and lipids concentration. For FeCl3 (0.2 mmol L-1) as flocculant, efficiency was 96.8%, and with NaOH (8 mmol L-1) 93.5%. Centrifugation efficiency was lower than with either flocculants: 91.7%. However, NaOH flocculation reduced lipid content, which did not occur with FeCl3. Flocculation efficiency was affected by salt concentration, reducing efficiency by 79% due to increased nutrient concentration (9 mL L-1)

Sonically-enhanced widgets: comments on Brewster and Clarke, ICAD 1997

This paper presents a review of the research surrounding the paper “The Design and Evaluation of a Sonically Enhanced Tool Palette” by Brewster and Clarke from ICAD 1997. A historical perspective is given followed by a discussion of how this work has fed into current developments in the area

Sistemas silvipastoris: estratégias para o desenvolvimento rural sustentável para a metade Sul do Estado do Rio Grande do Sul

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