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In this study, floatability rate of aluminum (Al) powders was analyzed for the purpose of separating valuable resources from residual materials in waste photovoltaic (PV) solar cells, and equations for flotation recovery were developed for various flotation types according to the rate-determining steps of the gas flowrate and feed rate. The flotation rate became a zero-order reaction at the rate-determining step of the gas flow rate and had the same form between a batch and continuous typed practices by substituting residence time with real time. Under the rate-determining step of the feed rate, the flotation rate was expressed by the linear combination of the first-order reaction of an even group material. The flotation recovery rate of Al powders was analyzed by the data of a batch floatability experiment and indicated by the linear expression of the first-order reaction of two groups due to the rate-determining step of the feed rate. The calculated separation recovery of n-cell type device increased as the number of cells increased and approached that of the batch and column types.

There are few study examples on the separation of metals by floating method. In this study, separation of silicon and aluminum, which are the main components of silicon-based solar cell module, was carried out by floating method in order to purify silicon from waste solar cell module. The selection of surfactant, control of electric charge, wettability of the solid particles, surface tensions, and bubble surface area are important for separation of solids by floating method. Sodium dodecyl sulfate (SDS) can increase the hydrophobicity of aluminum powder due to the difference of surface potentials between silicon and aluminum. SDS behaves as a collector of aluminum as well as a frothing agent to decrease the bubble size. At a SDS concentration of 2 g/L and sample dipping time of 10 min, 80.1 mass% of aluminum was floated and separated, and the sedimentary silicon reached a purity of 90.7% from a mixture of 50 mass% aluminum and 50 mass% silicon. Finally, at a pH value of 7.0, SDS concentration between 1.0 and 2.5 g/L and air flow rate of 2.5 L/min (STP) were suitable experimental conditions to purify silicon from a mixture of silicon and aluminum by flotation separation method.

A reliable representation of river terrains is essential to river research. Field surveys of river channel geometry are time‐consuming, costly, and logistically constrained and thus would encounter difficulties to achieve sufficient spatial coverage, resolution, and frequency of resurvey. This paper aims to demonstrate an efficient approach to building a river terrain model (RTM), the emphasis being on how to combine bathymetry and topography derived from satellite images captured at different flow stages. A method for calculating the difference between high and low stages (DHLS) based on the uniform‐flow theory is proposed. Calculations are carried out for a 13‐km long meandering section of the gravel‐bed Goulais River in Canada, which features pools and riffles, alternating point bars, and midchannel bars. A RTM for this complex section has been successfully produced. It consists of three data components: bathymetry at low stage, topography at high stage, and DHLS. The results capture realistic characteristics, including thalweg shift, steep outer banks, and gradual inner banks. They also show realistic longitudinal and lateral locations of pools and riffles. To illustrate potential applications of RTM, this paper has computed extreme bed shear stresses at bankfull discharge through hydrodynamics simulations of depth‐averaged flow in the river section and further estimated bed‐sediment grain‐size distributions. The estimates compare well with field measurements. The DHLS can vary significantly along a river channel. The proposed method for determining it is not site‐specific, and hence applicable to other rivers. The novelty of the methodology discussed lies in combining remote sensing techniques with physical flow laws.

Hydraulic jumps have complex flow structures, characterised by strong turbulence and large air contents. It is difficult to numerically predict the flows. It is necessary to bolster the existing computer models to emphasise the gas phase in hydraulic jumps, and avoid the pitfall of treating the phenomenon as a single-phase water flow. This paper aims to improve predictions of hydraulic jumps as bubbly two-phase flow. We allow for airflow above the free surface and air mass entrained across it. We use the Reynolds-averaged Navier–Stokes equations to describe fluid motion, the volume of fluid method to track the interface, and the k–e model for turbulence closure. A shear layer is shown to form between the bottom jet flow and the upper recirculation flow. The key to success in predicting the jet flow lies in formulating appropriate bottom boundary conditions. The majority of entrained air bubbles are advected downstream through the shear layer. Predictions of the recirculation region’s length and air volume fraction within the layer are validated by available measurements. The predictions show a linear growth of the shear layer. There is strong turbulence at the impingement, and the bulk of the turbulence kinetic energy is advected to the recirculation region via the shear layer. The predicted bottom-shear-stress distribution, with a peak value upstream of the toe of the jump and a decaying trend downstream, is realistic. This paper reveals a significant transient bottom shear stress associated with temporal fluctuations of mainly flow velocity in the jump. The prediction method discussed is useful for modelling hydraulic jumps and advancing the understanding of the complex flow phenomenon.

A novel technology involving radiofrequency heating and hydrogen peroxide (RF/H 2 O 2 ) was used for the treatment of dairy manure. RF/H 2 O 2 process efficacy was affected by power intensity, hydrogen peroxide dosage and holding time. The optimal conditions for nutrient release and solids disintegration were determined: for orthophosphate release, power intensity of 3 kW/L (kW/L substrate treated), holding time of 65 min and H 2 O 2 dose of 1%; and power intensity of 1.9 kW/L, holding time of 53 min and H 2 O 2 dose of 1.2% for soluble chemical oxygen demand concentration. The results indicated that the treatment efficacy of radiofrequency process was comparable to microwave process. However, the radiofrequency process required a longer holding time than microwave process. Nevertheless, energy required by the radiofrequency was lower than microwave as the radiofrequency system was capable of handling higher volumes of manure with higher solids content at a given time.

Named Data Networking (NDN) is one of the most promising future Internet architectures, which supports communications based on content names but not the content locations. Clients can retrieve content only by sending an Interest packet, which includes the content name. However, independent Interest packets will cause heavy loads on the routers, particularly in the Internet of Things (IoT) scenarios which will induce huge number of small-sized content exchanges. The proposed scheme enables clients to retrieve many different contents by sending an aggregated Interest packet. In addition, the Data packet can also be aggregated by the intermediate routers to improve the efficiency of NDN communications.

A novel push button is developed using shape-memory gels (SMGs). The Young’s modulus of SMGs changes dramatically with temperature. This modulus change is utilized to control the input-acceptable a...

Novel high-strength gels, named double network gels (DN gels), show a smart response to altering external electric field. It was reported that a plate shape of the DN gel bends toward a positive electrode direction when a static (DC) electric field is applied. Based on this previous result, it has been tried to develop a novel soft and wet actuator, which will be used as an automatically bulging button for cellar phones, or similar small devices. First, a bending experiment of a hung plate-shape DN gel was done, and its electric field response was confirmed. Second, the response of a lying plate-shape DN gels was confirmed in order to check the bulging phenomena. The edge of three plate-shape gels that was arranged radially on a plane surface was lifted 2mm by applying DC 8V. This system is a first step to make a gels button. However the critical problem is that electrolysis occurs simultaneously under electric field. Then, the water sweep out from gels, and gels is shrinking; They cause the separation between aluminum foil working as electrode and gels. That is why, a flexible electrode should be made by gels completely attached to the gels. As a third step, a push button is tried to make by a shape memory gels (SMG). The Young's modulus of the SMG is dramatically changed by temperature. This change in the modulus is applied to control the input-acceptable state and input-not-acceptable states of the button. A novel push button is proposed as a trial, and its user-friendliness is checked by changing the size of the button. The button is deformed by pushing and is back to original shape due to the property of shape memory. We believe the mechanism of this button will be applied to develop new devices especially for visually impaired persons.