In order to tackle the high compute cost of the multiphase simulations for dense medium cyclones, the development of an open source high fidelity LES based algebraic slip mixture multiphase flow solver is presented. The solver is parallelized on a general purpose GPU using a full load model, which provides around 13 times speed up as compared to a CPU implementation thereby, making design explorations using the current solver more feasible and less time consuming. The traditional ASM model was improved upon using more realistic slurry viscosity model and polydispersed hindered correlation for dense medium operation. The performance of the developed solver for dense medium cyclone operation was validated with the literature based gamma ray tomography (GRT) experimental results. The solver was then used to study the implication of variation in the key aspects of DMC operation such as pressure head, underflow diameter and feed particle concentration. The medium segregation is explained based on a novel non-dimensional force analysis of the drag, shear lift and turbulent dispersion. Finally, the response of the DMC in terms of hydrodynamic force analysis and density differential with the variation in design and operating variables has discussed. Based on the comprehensive force analysis of the medium a justification is provided as to why a lower pressure head is preferred for DMCs used in mineral processing.

In general, the washing of coal is greatly influenced by the amount of near-gravity material (NGM) present at the desired cut density. It is observed that the presence of a high percentage of NGM coal results in significant misplacement of particles to wrong products and reduces the separation efficiency of dense medium cyclone (DMC). In this work, an attempt is made to study the behavior of different sizes of NGM coal particles at three feed relative densities inside 350 mm DMC using a discrete phase model (DPM) superimposed on the magnetite medium segregation simulated by modified mixture model. The Reynolds stress model (RSM) is used to resolve turbulence. The DPM is adopted to track different sizes and densities of coal particles, and then a partition curve is constructed to calculate the Ecart probable (Ep) error, percent misplacement, and imperfection. The results show that the lighter and heavier density coal particles away from the separation cut density exhibit very short residence times. Fine-sized coal particles close to the cut density have a significant misplacement compared to the coarse-sized particles having the same density. It is also observed that NGM coal particles show very long residence times irrespective of size.

Here, an unobtrusive, adhesive‐integrated electrode array for continuous monitoring of stomach electric activity is introduced. This patient‐friendly, disposable peel‐and‐stick adhesive device represents an important advancement over existing arrays that require placement of each electrode individually and are thus also labor intensive and are in general more rigid and cumbersome. In comparison to other silver–silver chloride electrodes, this skin conformal array does not require gel and thus can withstand low impedance over the duration of long recordings. Interfacing these electrodes with miniaturized electronic recording and wireless telemetry systems has the potential to enable scalable population health opportunities to perform objective gastrointestinal assessment and optimization of treatment regimens.

Semi solid flow batteries (SSFB) are developed by forming suspensions of electrochemically active and conductive particles for use as an anolyte or catholyte in a redox flow battery. By utilizing micron-scale powders from mature battery chemistries in a flowable suspension, the benefits of energy-dense intercalation chemistries with the scalability of flow battery architectures can be combined for low cost electrochemical storage. Presently, a narrow set of materials has been explored, focusing on chemistries with a lithium anode. In this work, a magnesium SSFB with an optimized MoS2 cathodic slurry is demonstrated as a low cost, high material abundance alternative to lithium-based chemistries. A mixed ionic-electronic conductive network is designed around a dual-ion (Mg, Li) electrolyte, by combining the all-phenyl complex (APC) + LiCl, MoS2, and ketjen black (KB) to form the cathodic slurry. The rheological, electrical, and electrochemical properties of MoS2-KB-APC slurries with varying compositions have been measured. Full cells, with a Mg foil anode and MoS2 slurry cathode, are shown to cycle reversibly for 20 cycles at C/5 in a non-flowing configuration, reaching 180 mAh/g discharge capacity. LiCl concentration and KB concentration are identified as critical to high capacity slurry cathodes. The relative impacts of Mg and Li ions are quantitatively analyzed, showing that both ions are reversibly intercalated during cycling. Finally, a custom flow cell is used to demonstrate 120 mAh/g discharge capacity at C/8, highlighting the flowable nature of the cathode suspension. This work provides experimental data and insight into how existing low cost material sets can be utilized in a semi solid flow battery architecture. Figure 1

In the diffusion bonded (DB) joints, two interfaces exist, one between the base metal Ti-6Al-4 V and brass interlayer, and the second one between the brass interlayer and base metal AISI 304L stainless steel. The interfacial reaction products formed at the interfaces were examined with optical, scanning electron microscope (SEM), energy dispersive X-ray diffraction analysis (EDAX). Diffusion bonding (DB) experiments were carried out in the temperature range of 800-850 degrees C with an interval of 25 degrees C, holding time 60, 90 and 120 min, and under pressures 4 and 8 MPa. Maximum tensile strength of 218 MPa was realised for the samples processed at 850 degrees C, 60 min, and 8 MPa. At the interface between T-6Al-4 V and brass the maximum hardness values of 548.2 VHN was realized for the sample bonded at 850 degrees C. The XRD performed at the fracture site, indicated the presence of intermetallic compounds such as CuTi, CuTi2, Cu5Zn8, Fe22Zn78, gamma (gamma) and sigma (sigma) phases and pure 'Cu'. (C) 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the International Conference on Advanced Materials Behavior and Characterization.

PURPOSE: This study was aimed to review the different methods for reproduction of tilt of a cast on a surveyor. METHODOLOGY: An electronic literature search was conducted through Medline via Pubmed, Wiley Online library, Ebscohost, Science Direct, as well as the Google Scholar for article published between October 1973 and March 2016, using the key words, tilt of cast, surveying, path of insertion, preservation of tilt and reproduction of tilt. A total of 20 articles were found out of these 8 were not related to present search and hence were excluded from the study. Finally 12 articles were found to be relevant. RESULTS: All the techniques given by the different authors are having both advantages and disadvantages. CONCLUSION: The path of insertion of a removable partial denture must be determined during treatment planning and permanently recorded on the cast. Literature has suggested several methods for the reproduction of cast tilt on surveyors.

Graphene‐based composites have received attention as part of the drive towards next‐generation electronic and energy‐storage technologies. However, current graphene synthesis methods are limited by complex, time‐consuming, toxic, costly, and/or often low‐yield procedures. The synthesis of a novel stretchable graphene‐polyurethane‐poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate ink aimed at printing wearable electronics is reported. The procedure is based on low‐cost high‐yield production of high‐performance graphene ink produced by laser induction of polyimide film followed by harvesting the graphene. Screen printing is used to fabricate flexible and intrinsically stretchable micro‐supercapacitors (S‐MSCs) printed on different substrates. The resulting graphene‐based printed S‐MSCs display a remarkably high capacitive performance and attractive mechanical resiliency. High specific areal capacitance, above 23 mF cm −2 , is achieved, which is the highest areal capacitance reported for highly stretchable, printed graphene supercapacitors. A repeated (200 cycles) stretchability beyond 100% is obtained while maintaining more than 85% of the S‐MSCs' original capacitance. This unique and highly scalable graphene ink synthesis method holds considerable promise for application in low‐cost graphene‐based chemical formulation, especially in the field of printed and wearable electronics toward multifunctional, energy‐storage systems capable of withstanding severe mechanical deformation while maintaining their optimal electrochemical performance.

Pipeline transportation of iron ore fines slurry at high solids concentration from the source to the site of its utilization has technological as well as economical implications. In the present scenario, major Indian iron and steel producers are aiming for transporting the run-of-mine (ROM) iron ore through slurry pipelines at a competitive price. Thus, it is quite imperative to study the flow characteristics of concentrated iron ore fines slurry for predicting the pumping pressure as well as designing such commercial slurry pipelines. This paper presents the results of the flow behaviour of specific Indian iron ore samples in a solids concentration range of 60-78% by mass using a HAAKE Rotational Rheometer (Model: RheoStress 1, Thermo Fisher Scientific). The rheological characteristics of the fines slurry samples indicated non-Newtonian flow behaviour and fitted the Bingham Plastic model well in the studied range of concentrations. The influence of solids concentration on yield stress and viscosity of the iron ore fines slurry samples were discussed and presented in the paper. The pressure drop for the concentrated slurry in larger size pipes (300, 350, 400 & 450 mm NB pipes) were predicted by employing non-Newtonian head loss models. Attempts have been made to optimize the operational pipe flow parameters with respect to specific energy consumption (SEC) and the basic design of a commercial scale iron ore slurry pipeline with annual conveying capacity of ~ 12.6 million tons has been worked out.

The current beneficiation study examines the potential for separating ultrafine low-grade iron ore materials using a circulating-type air classifier. Statistical analysis using Response Surface Methodology (RSM) was implemented for optimization of the separator critical processing parameters to achieve sharp separation at a cut size as fine as 20-38 mu m. Results demonstrated that it was possible to achieve a separation of about 9.21% lean grade ultrafine content with a size cut of similar to d(50) 20 mu m through a single-stage application.

Developing low cost energy storage for integrated electronics depends on the ability to increase energy densities while reducing materials and manufacturing costs. Among the several next generation battery chemistries currently being explored, Zn-air batteries are well suited to tackle these challenges and power a wide variety of electronics applications. Zn-air batteries provide a high theoretical energy density, exhibit high performance at high discharge rates, and use low cost, earth abundant materials. Additionally, Zn-air batteries utilize aqueous, non-flammable electrolytes and can be processed entirely in air, making them an emerging candidate to replace Li-ion batteries. Despite their significant promise, side reactions at the Zn anode limit Zn-air battery performance and reduce practical energy densities. Zn corrosion follows a complex series of intermediate reactions in an alkaline environment and is highly dependent on properties of the electrolyte (OH- concentration and use of additives), properties of the electrode (film porosity and active particle size), and cell operating conditions (temperature, current density, depth of discharge, and cell geometry). Thus, each of these factors can alter the fundamental Zn corrosion mechanism and need to be studied systematically to understand their influence on Zn-air battery stability and performance. Previous studies on Zn corrosion have identified single factors that influence reactions at the anode, but typically rely on ex-situ characterization methods that are not representative of the transient and non-equilibrium nature of electrochemical interfaces. In this work, we investigate corrosion in printed Zn-air batteries through the use of operando characterization techniques including differential electrochemical mass spectroscopy (DEMS), X-ray diffraction (XRD), and X-ray absorption spectroscopy (XAS). This approach couples electrochemical measurements with chemical and structural information to directly probe the reaction products at an electrochemical interface and observe non-equilibrium reactions in real time. Moreover, Zn-air batteries are rapidly processed using additive manufacturing in order to investigate several experimental factors in parallel and determine their impact on Zn corrosion. Using this combined approach, we aim to understand which experimental factors significantly influence Zn corrosion in order to identify methods for mitigating self-discharge and improving Zn utilization in Zn-air batteries. DEMS experiments, coupled with operando pressure decay analysis, are used to quantify hydrogen evolution rates at the Zn anode and are used to compare corrosion rates across various cell designs. Through this technique, we examine the effects of current collector type, electrode mass loading, electrode size, and electrolyte concentration on Zn corrosion rates. Based on our results, electrolyte concentration and current collector material have the greatest influence on corrosion rate among the factors studied, while electrode size and electrode mass loading have little effect on corrosion rates. Through operando XRD, we confirm the formation of a passivating oxide layer at the Zn anode and observe that higher electrolyte concentrations lead to faster passivation of the anode under both discharge and open-circuit conditions. Cell potential is also measured during these experiments and is correlated to the fractional amounts of Zn and oxide species in the anode, suggesting that cell potential can be used as a marker for battery lifetime. In addition, operando XAS experiments show characteristic shifts in the Zn K-edge during the passivation process, corresponding to a change in the Zn valence state during oxidation. These shifts are highly dependent on electrolyte concentration, but show little dependence on electrode geometry or mass loading.

Printed batteries are an emerging solution for integrated energy storage using low‐cost, high accuracy fabrication techniques. While several printed batteries have been previously shown, few have designed a battery that can be incorporated into an integrated device. Specifically, a fully printed battery with a small active electrode area (<1 cm2) achieving high areal capacities (>10 mAh cm−2) at high current densities (1–10 mA cm−2) has not been demonstrated, which represents the minimum form‐factor and performance requirements for many low‐power device applications. This work addresses these challenges by investigating the scaling limits of a fully printed Zn–Ag2O battery and determining the electrochemical limitations for a mm2‐scale battery. Processed entirely in air, Zn–Ag2O batteries are well suited for integration in typical semiconductor packaging flows compared to lithium‐based chemistries. Printed cells with electrodes as small as 1 mm2 maintain steady operating voltages above (>1.4 V) at high current densities (1–12 mA cm−2) and achieve the highest reported areal capacity for a fully printed battery at 11 mAh cm−2. The findings represent the first demonstration of a small, packaged, fully printed Zn–Ag2O battery with high areal capacities at high current densities, a crucial step toward realizing chip‐scale energy storage for integrated electronic systems.

The influence of particle size, blend ratio and some selective bio-additives on the rheological behaviour of an Indian iron ore sample in a slurry concentration range of 60-75% by mass was evaluated.The rheological parameters were measured using a high-precision ThermoFisher Scientific HAAKE TM RheoStress TM 1 Rheometer.The iron ore slurry samples indicated non-Newtonian flow behaviour and fitted quite well with the Bingham plastic model in the studied range of concentrations.The specific multimodal iron ore samples with a broad size distribution indicated a substantial reduction in slurry viscosity, yield stress and improved solids loading compared to monomodal ones.The reduction in apparent viscosity at a given shear rate for the specific iron ore slurry sample was correlated to a distribution modulus () derived from the Farris theory.The application of small dosages (0.8-1% w/w of total solids) of two selective bio-additives extracted from Indian spinach (Basella alba) and Bellyache bush (Jatropha gossypifolia Linn) further reduced the Bingham viscosity and yield stress values through surface modification at higher solids loading.The increase in yield stress values with an increase in solids concentration was attributed to the formation of loosely packed flocs and immobilisation of water within them, thus increasing particle-particle and particle-fluid friction.The bio-additives may be able to improve the fluid mobility among the particles, thus reducing the internal friction constituting the flocs and facilitating the slurry flow with the application of a reasonably lesser shearing force.The study reveals that the blending of fines with coarse iron ore at a controlled particle size distribution supplemented by small dosages of low-cost additives may be employed for preparation and transportation of high-concentration iron ore slurry with improved pipe economics.

Inorganic transparent metal oxides represent one of the highest performing material systems for thin-film flexible electronics. Integrating these materials with low-temperature processing and printing technologies could fuel the next generation of ubiquitous transparent devices. In this work, we investigate the integration of UV-annealing with inkjet printing, demonstrating how UV-annealing of high- k AlO x dielectrics facilitates the fabrication of high-performance InO x transistors at low processing temperatures and improves bias-stress stability of devices with all-printed dielectrics, semiconductors, and source/drain electrodes. First, the influence of UV-annealing on printed metal-insulator-metal capacitors is explored, illustrating the effects of UV-annealing on the electrical, chemical, and morphological properties of the printed gate dielectrics. Utilizing these dielectrics, printed InO x transistors were fabricated which achieved exceptional performance at low process temperatures (<250 °C), with linear mobility μlin ≈ 12 ± 1.6 cm2/V s, subthreshold slope <150 mV/dec, Ion/ Ioff > 107, and minimal hysteresis (<50 mV). Importantly, detailed characterization of these UV-annealed printed devices reveals enhanced operational stability, with reduced threshold voltage ( Vt) shifts and more stable on-current. This work highlights a unique, synergistic interaction between low-temperature-processed high- k dielectrics and printed metal oxide semiconductors.

Current methods to create 3D structures are limited to few materials and designs, are costly, and have low processing throughput. Planar designs (of printed sacrificial, flexible, and guiding layers) fabricated by thick film technique that can reversibly fold between their 2D and 3D forms through compressive buckling and selective bonding is reported in this work. Versatile ink compositions based on a wide variety of materials (e.g., carbonaceous, polymers, and nanomaterials) are used along with screen printing technique for creating variety of desired 3D structures, such as spirals, squares, and spikes. Various composite inks are printed onto substrates containing a printed sacrificial layer for selective binding, and the substrate can be prestretched for a controlled buckling process. Removal of the sacrificial layer and release of the strained substrate leads to the folding of the flat printed structures into targeted respective 3D architectures. Such use of planar screen-printed layers to create 3D shapes brings several technological advantages, including broad selection of materials, large-scale processing at low cost, and incorporation of numerous functional technologies. The successful control of such printed 3D architectures offers a promising route to enable numerous applications based on large variety of materials.

Multistimuli-responsive camouflaging and autonomously propelled swimmers are presented. These bioinspired artificial swimmers are capable of color changing in response to a variety of environmental stimuli such as temperature, pH, and light. By multiplexing different stimuli responsive materials on a single swimmer, a vast library of independently addressable colors can be achieved. Unlike other color-changing robots, our color-changing swimmers can move autonomously in solution and are decoupled from tethered supports. The utilized leuco dyes, pH indicators, and phosphorescent powders display excellent reversibility and prolonged color retention. Finally, we design camouflage patterns which render the swimmers invisible against virtually any background, while revealing the swimmer upon changing the environmental conditions. By mimicking animal camouflage strategies these artificial swimmers present a significant step toward realizing multienvironmental stimuli-responsive color-changing strategies for the next generation of smart robotics. Such capabilities can be further enhanced by coupling color-changing ability with stimuli-triggered speed or shape change.

This work describes a flexible and stretchable battery pack configuration that exhibits highly stable performance under large deformation up to 100% biaxial stretching. Using stress-enduring printable inks and serpentine interconnects, the new screen-printing route offers an attractive solution for converting rigid battery units into a flexible, stretchable energy storage device. Coin-cell lithium ion batteries are thus assembled onto the island regions of a screen-printed, buckling-enabled, polymer-reinforced interconnect "island-bridge" array. Most of the strain on the new energy-storage device is thus accommodated by the stress-enduring serpentine structures, and the array is further reinforced by mechanically strong "backbone" layers. Battery pack arrays are assembled and tested under different deformation levels, demonstrating a highly stable performance (<2.5% change) under all test conditions. A light emitting diode band powered by the battery pack is tested on-body, showing uninterrupted illumination regardless of any degrees of deformation. Moreover, battery-powered devices that are ultrastable under large deformation can be easily fabricated by incorporating different electronics parts such as sensors or integrated circuits on the same platform. Such ability to apply traditionally rigid, bulky lithium ion batteries onto flexible and stretchable printed surfaces holds considerable promise for diverse wearable applications.

The major environmental impacts from tailing disposal can be divided into two categories: (1) The loss of productive land following its conversion to tailing dump, and (2) the introduction of sediment, acidity, and other contaminants into the ecosystem. The tailing system continues to generate opposition from local communities, the general public, and non-government organizations (NGO). The project was completed as follows: (1) Identification, characterization and settling study; (2) Preparation of synthetic tailing mixtures; (3) Characterization and settling studies; (4) Pressure filtration and paste thickening studies; (5) Study of flow properties of filtered tailings and rheology of thickened (paste) tailings; (6) Assess the transportability of filtered and paste tailings; (7) To evaluate the flow properties and paste rheology (8) Address issues related to the storage and transportation. The project concluded that tailing samples are amenable for paste thickening as well as filtration. It is possible to get a paste with 56-72% solids and yield stress in the range of 75-300 Pa. The tests revealed that it is possible to produce a filter cake with moisture content ranging from 14 to 24%.

Developing low cost energy storage for integrated electronic applications depends on the ability to increase energy densities while reducing materials and manufacturing costs. Metal-air batteries are an emerging solution for next-generation energy storage given their superior theoretical energy storage capacity and use of low cost, earth abundant, and lightweight anode materials such as Zn, Al, and Mg. While metal-air batteries offer significant promise, inefficiencies at the air cathode dominate cell performance and limit practical energy densities. Recent studies in metal-air batteries have introduced new electrocatalysts to improve cathodic efficiency, but often rely on elevated temperatures and prolonged processing times to achieve suitable performance. Thus, rapid synthesis of air cathodes at low temperatures remains a significant challenge for mass production of metal-air batteries. In this work, we establish a printed air cathode architecture that can be fabricated below 100 °C, broadening the potential applications for metal-air batteries by lowering overall manufacturing costs and improving process compatibility for integrated systems. Furthermore, we investigate the importance of binder, solvent, and catalyst interactions and their influence on air cathode performance in a primary Zn-air battery. Additive manufacturing is used to demonstrate high throughput deposition and high accuracy patterning of metal-air battery materials. Stencil printing is chosen as a proof of concept technique to assemble the air cathode and Zn-air battery. Analogous to screen printing, stencil printing is capable of achieving thick active layers (10s-100s µm) for high capacity electrodes and is compatible with a variety of substrates including silicon wafers and flexible plastics. Cathode inks using polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE) were compared to study the effects of the binder and associated solvent on the oxygen reduction reaction (ORR) as a function of processing temperature. Using a commercially available carbon powder with a platinum catalyst, cathodic half-cells were constructed to measure cell impedance and ORR overpotential as a function of binder material and annealing temperature. Thermogravimetric analysis (TGA) and x-ray photoelectron spectroscopy (XPS) were used to identify compositional changes, in both the cathode inks and printed films, related to solvent evaporation and binder degradation during annealing. Moreover, in operando pressure decay and differential electrochemical mass spectroscopy (DEMS) measurements were conducted to determine ORR efficiencies for the printed cathodes. After characterizing the printed air cathodes, printed Zn-air full-cells were fabricated to demonstrate the dependence of cell performance on binder type and annealing temperature. Higher operating voltages at a given current density were observed in cells with the PTFE binder compared to the PVDF binder, with the PTFE cells maintaining operating voltages above 1 V at current densities up to 24 mA cm-2. As a result, the PTFE cells exhibited peak power densities between 25-30 mW cm-2 at annealing temperatures as low as 80 °C, compared to 12 mW cm-2 at 350 °C for the PVDF cells. PTFE cells also displayed internal resistances less than 50 Ω with areal capacities between 2-5 mAh cm-2 with platinum concentrations as low as 5 wt%. This work represents the first demonstration of a low temperature printed air cathode for metal-air batteries. Our printed cathodes are broadly applicable to other aqueous metal-air battery systems and present a novel solution to fabricating low cost, high energy density batteries. The cathode inks are also compatible with several high throughput patterning techniques, including screen printing and slot-die coating, and could help achieve greater penetration of energy storage in emerging applications such as wearable and flexible electronics.

A soft, stretchable wearable biofuel cell producing ∼1 mW power from sweat is presented.

The field of printed wearable electronics has witnessed spectacular growth due to its promise to offer low‐cost, high‐performance devices for a broad range of applications. Among the sub‐fields of printed wearable electronics, printed wearable electrochemical systems are of special importance due to their widespread applications in healthcare, energy and security fields. These systems have opened up new avenues for body‐integrated electronics that were earlier impossible to achieve. These include wearable energy systems and sensors for a wide variety of applications. Much of the success of printed wearable electrochemical systems can be attributed to innovations in materials engineering that have led to novel inks comprising of new nanomaterials, polymers and composites. New generation of printed electrochemical devices include soft, stretchable and anatomically‐compliant devices that enable efficient bio‐integration and withstand high tensile stress associated with on‐body applications. Progress in materials science has also led to the development of self‐healing printed electrochemical systems for wearable applications. This review provides an overview of the key material requirements for ink formulations for realizing efficient wearable electrochemical systems such as batteries, supercapacitors, biofuel cells and sensors. Finally, major challenges impeding the field of wearable electrochemical systems are discussed along with future prospects of this exciting field.