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Abstract The direct carbon fuel cells with solid oxide electrolyte (DC-SOFC) and anodes deposited by inject printing (EM/DCIJP) were studied. The cells were fed with carbon fuel obtained by the direct RF plasma splitting of methane. Since the (EM/DCIJP)M/DCIJP technology allows easy modification of electrode material, the effect of Cu addition to the Ni–YSZ anode was investigated. The significant improvement of the cell performance with the new anode was observed.

AbstractIn this manuscript we reply to the issues raised by G. Bagheri and C. Bonadonna in their comment 2019JB017697. We reiterate our definition of particle Reynolds number, which is appropriate for our data set of experimental measurements, and we show that the poor performance of Bagheri and Bonadonna (2016, https://doi.org/10.1016/j.powtec.2016.06.015) model discussed in Dioguardi et al. (2018, https://doi.org/10.1002/2017JB014926) was mainly due to the typos in the equations presented in their original manuscript. We believe that the iterative methodology for calculating the drag coefficient is not strictly necessary for our data set. In this reply, however, we also include results of the intercomparison study among different drag models using the iterative methodology. Results show that the performance of the different drag models considered in the intercomparison study is not significantly affected by the employed methodology (direct vs. iterative) and that, regardless the employed methodology and unlike what has been stated in the comment 2019JB017697, our model has the best performance in reproducing the experimentally measured terminal velocities.

Use of a pilot-scale fixed-film bioreactor was investigated for remediation of bromate contamination within groundwater. Bromate reduction with stoichiometric production of bromide was observed, providing supporting evidence for complete reduction of bromate with no production of stable intermediates. Reduction of 87-90% bromate from an influent concentration of 1.1 mg L(-1) was observed with retention times of 40-80 h. Lower retention times led to decreases in bromate reduction capability, with 11.5% removal at a 10 h retention time. Nitrate reduction of 76-99% from a 30.7 mg L(-1) as NO(3)(-) influent was observed at retention times of 10-80 h, although an increase in nitrite production to 2.7 mg L(-1) occurred with a 10 h retention time. Backwashing was not required, with the large plastic packing media able to accommodate biomass accumulation without decreases in operational efficiency. This study has provided proof of concept and demonstrated the potential of biological bromate reduction by fixed-film processes for remediation of a bromate contaminated groundwater source.

Abstract The almost two-dimensional steady-state rates of heat loss from arrays of uniformly-spaced vertical rectangular fins, extending upwards—in otherwise stagnant air—from horizontal heated bases, have been measured. (The vertical air gaps between the fins were closed at their sides, by insulated vertical end-barriers.) The effects of various combinations of height, thickness and spacing of the fins, for different base temperatures (in the range 40 to 100°C), have been studied. For the configuration considered, in a normal ambient environment (∼ 20°C), there is an optimal fin spacing (⋍ 16 mm) corresponding to the greatest steady-state rate of free convective/conductive heat loss through the air from the finned system, and this is almost independent of the temperature of the heat exchanger base (in the range 40–100°C). At this optimal spacing for base temperatures not greater than 50°C, the convective/conductive heat transfer rate from the array increases with the fin height up to about 60 mm, so that it would be uneconomic to employ taller fins if convection/conduction is dominant compared with radiation. If the radiation contribution is also considered, then the optimal spacing corresponding to the maximum total steady-state rate of heat loss through the air is somewhat less than the optimal spacing for which, under the same temperature conditions, the maximum steady-state rate of convective/conductive heat leak occurs. The greater the emissivity of the heat exchanger surfaces, the narrower the optimal uniform gaps between the fins. A two-dimensional finite-difference computer program has been composed to predict the temperature distribution throughout the heat exchanger for a stipulated ambient environmental temperature and experimentally-determined distribution of the heat transfer coefficient over the surfaces of the exchanger. This enables, for instance, any hot spots to be located prior to a proposed design being built.

Abstract This paper addresses the problem of how to synthesize mass and heat exchange processes, in which stream flowrates and their inlet compositions and temperatures may vary according to a set of discrete values. A unified hyperstructure representation of mass and heat exchange alternatives is introduced to account for all mass and heat integration possibilities. A multiperiod mixed integer nonlinear programming (MINLP) model is then developed, where a total annualized cost is minimized by balancing capital investment cost (of the heat and mass exchange equipment and their interconnections) to operating cost (of the hot-cold utilities, mass separating agents, etc.). As illustrated with the example problems, the proposed model can be effectively employed for the synthesis of flexible heat exchanger networks (HENs) and mass exchanger networks (MENs) separately or, for the synthesis of separation processes involving both heat and mass transfer.

Turbulent spots were generated artificially to simulate natural spots in the transitional boundary layer. The spots at the final stage under zero and adverse pressure gradients were measured using conventional hotwire anemometry technique. Ensemble averages of the velocity traces were calculated and velocity profiles through the spots and the surrounding region were plotted. The spots are represented by the ensemble average of the velocity perturbations. The integral boundary layer properties are derived and compared through the spots. The effect of the pressure gradient on the turbulent spots is analysed with the structure of the spots and the ‘calmed region’ following the spots.

Genuine Savings (GS), also known as ‘net adjusted savings’, is a composite indicator of the sustainability of economic development. Genuine Savings reflects year-on-year changes in the total wealth or capital of a country, including net investment in produced capita, investment in human capital, depletion of natural resources, and damage caused by pollution. A negative Genuine Savings rate suggests that the stock of national wealth is declining and that future utility must be less than current utility, indicating that economic development is non-sustainable (Hamilton and Clemens, 1999). We make use of data over a 150 year period to examine the relationship between Genuine Savings and a number of indicators of well-being over time, and compare the relative changes in human, produced, and components of natural capital over the period. Overall, we find that the magnitude of genuine savings is positively related to changes in future consumption, with some evidence of a cointegrating relationship. However, the relationships between genuine savings and infant mortality or average heights are less clear.

A data correction method to eliminate the effect of local tissue-accelerometer vibration from surface measurements of vibration over the spine has been developed and compared with previous direct measurements. A single degree-of-freedom linear model for the local tissue-accelerometer system in the vertical and the fore-and-aft axes is assumed. The natural frequency and the damping ratio of the local system are estimated so as to form a correction frequency function, using spectral analysis of the free vibration response of the local system caused by transient displacements of the accelerometer attached to the body surface. Accelerometers were attached to the skin over the spinous process of the vertebra L3 and on the abdominal wall. For four different masses and each site, correction frequency functions were computed. Seated subjects were then exposed to vertical random vibration (0.5-35 Hz) and acceleration transfer functions from the seat to each accelerometer were calculated. Different transfer functions were obtained with different additional masses but the differences were eliminated by the correction method so as to indicate the transfer functions to the spine and the viscera. For vertical responses, the correction method was effective at frequencies below the estimated natural frequencies of the local system. Fore-and-aft response over the spine did not require correction at frequencies below 35 Hz.