Functionalized Hybrid Coatings on ABS Surfaces by PLD and Dip Coatings

It is important to give water-repellent and antibacterial properties to the acrylonitrile butadiene styrene (ABS) surfaces of the hearing aids. In this study, the sol–gel Si and sol–gel Ti solutions were prepared from the reactions of silicon ethoxide, titanium butoxide and methacrylic acid. The catalyst and Dynasylan F8815 were added to the sol–gel solutions to give hydrophobic properties onto the ABS surfaces. Additionally, silver nanoparticles were synthesized by nanosecond laser and added to the coating solutions to give extra antibacterial properties. The surfaces of the ABS targets were coated using the sol–gel dip coating and pulsed laser deposition techniques. The coatings with good adhesion between film and substrate and good water-repellent properties were achieved. The average contact angles for the coated ABS surfaces were measured in the range between 120 and 125 degrees. The obtained sol–gel materials and produced thin films onto the ABS surfaces were also analyzed in terms of the antibacterial properties. The highly antibacterial properties were observed in the sol–gel solutions and the thin films.     

Processing and 3D printing of SiCN polymer-derived ceramics

Preceramic polymer resins are attractive for the 3D printing of net-shaped ceramic components. Recently various processes have been demonstrated for 3D printing of polymer-derived ceramics (PDCs). Ultimately in these processes, the process outcomes strongly depend on the process parameters. In particular, for PDCs the ceramic density, and ceramic yield are affected by the catalyst concentration and cross-linking duration. Here, we use thermal analysis and FTIR to quantify the interrelation of the process parameters on the process outcome for polysilazanes and demonstrate 3D printing of PDC components based on the best-identified process parameters. The results of this work can be used as guidelines for future additive manufacturing of PDCs.     

Influence of Chemical Reaction on Mass Transport in Yield Stress Exhibiting Flow Regime

Theoretical Foundations of Chemical Engineering - In this study, the simulations for first-order chemical reactions (constructive and destructive) in the flow of the Casson fluid with...     

The Therapeutic Potential of Exosomes in Soft Tissue Repair and Regeneration

Soft tissue defects are common following trauma and tumor extirpation. These injuries can result in poor functional recovery and lead to a diminished quality of life. The healing of skin and muscle is a complex process that, at present, leads to incomplete recovery and scarring. Regenerative medicine may offer the opportunity to improve the healing process and functional outcomes. Barriers to regenerative strategies have included cost, regulatory hurdles, and the need for cell-based therapies. In recent years, exosomes, or extracellular vesicles, have gained tremendous attention in the field of soft tissue repair and regeneration. These nanosized extracellular particles (30–140 nm) can break the cellular boundaries, as well as facilitate intracellular signal delivery in various regenerative physiologic and pathologic processes. Existing studies have established the potential of exosomes in regenerating tendons, skeletal muscles, and peripheral nerves through different mechanisms, including promoting myogenesis, increasing tenocyte differentiation and enhancing neurite outgrowth, and the proliferation of Schwann cells. These exosomes can be stored for immediate use in the operating room, and can be produced cost efficiently. In this article, we critically review the current advances of exosomes in soft tissue (tendons, skeletal muscles, and peripheral nerves) healing. Additionally, new directions for clinical applications in the future will be discussed.     

Morphology‐dependent electrocatalytic activity of nanostructured Pt/C particles from hybrid aerosol–colloid process

An optimum nanostructure and pore size of catalyst supports is very important in achieving high catalytic performances. In this instance, we evaluated the effects of various carbon nanostructures on the catalytic performances of carbon‐supported platinum (Pt/C) electrocatalysts experimentally and numerically. The Pt/C catalysts were prepared using a hybrid method involving the preparation of dense, hollow, and porous nanostructured carbon particle via aerosol spray pyrolysis followed by microwave‐assisted Pt deposition. Electrochemical characterization of the catalysts showed that the porous Pt/C catalyst gave the best performance; its electrochemical surface area was much higher, more than twice than those of hollow or dense Pt/C. The effects of pore size on electrocatalysis were also studied. The results showed the importance of a balance between mesopores and macropores for effective catalysis with a high charge transfer rate. A fluid flow model showed that good oxygen transport contributed to the catalytic activity. © 2015 American Institute of Chemical Engineers AIChE J, 62: 440–450, 2016     

Performance Assessment of a Potato Crisp Frying Process

Frying is a common and popular cooking method, which has been widely used in food manufacturing, though it is a very energy-intensive process. Energy analysis has been commonly used to assess the performance of fryers. In this study, we attempted to exergetically assess the performance of a potato crisp frying system, which consists of three main components, a combustor, a heat exchanger, and a fryer. In the analysis, we utilized the actual operational data obtained from the literature. We determined exergy destruction in each system component and the whole system. We calculated universal and functional exergy efficiency values for the system components and compared them with each other. We also undertook a parametric study to investigate how the overall cycle performance was affected by changing the reference environment temperature and some operating conditions. We illustrated the exergy results through the Grassmann (exergy loss and flow) diagram. We calculated the universal exergetic efficiency values of 58, 82, and 77% for the combustor, heat exchanger, and fryer, respectively, with a universal exergetic efficiency value of 4% for the whole frying system. We found that the fryer had the highest functional exergetic efficiency value of 74%, followed by the heat exchanger with 47% and the combustor with 0.08%.     

Controlling the phase behavior of block copolymers via sequential block growth

Block copolymers remain one of the most extensively investigated classes of polymers due to their abilities to self-organize into various nanostructures and modify polymer/polymer interfaces. Despite fundamental and technological interest in these materials, only a handful of experimental phase diagrams exist due to the laborious task of preparing such diagrams. In this work, two copolymer series are each synthesized from a single macromolecule via sequential living anionic polymerization to yield molecularly asymmetric diblock and triblock copolymers systematically varying in composition. The phase behavior and morphology of these copolymers are experimentally interrogated and quantitatively compared with predictions from mean-field theories, which probe copolymer phase behavior beyond current experimental conditions.     

On the feasibility of community-scale photovoltaic-powered reverse osmosis desalination systems for remote locations

This paper presents a generalized methodology to evaluate the feasibility of photovoltaic-powered reverse osmosis (PVRO) systems for small, remote communities in challenging environments. The economic feasibility is determined by comparing the cost of water from a photovoltaic reverse osmosis system with the cost of water obtained using conventional diesel-powered reverse osmosis. For PVRO systems, the feasibility is a function of location due to variation in solar resource, water type, system demand and local governmental policies. A series of sample cases were analyzed to demonstrate the method. Analysis for community-scale seawater reverse osmosis systems was carried out for various locations using Geographic Information System (GIS) data. A site-specific analysis has been completed for seawater and brackish water reverse osmosis systems. It was found that photovoltaic-powered reverse osmosis is feasible for the majority of remote locations with a large solar resource.     

Discrete‐time Lyapunov stable‐staggered estimator MIMO adaptive interference cancelation with experimental verification

Adaptive interference cancelation is of vital importance in a broad array of scientific and engineering disciplines. In this paper we develop a closed‐loop discrete‐time interference cancelation algorithm. The novel features of this algorithm are its ability to deal with multiple channels being affected by interferences with different frequency spectrums. Also we provide a proof of Lyapunov stability of closed‐loop system and asymptotically perfect interference cancelation for a class of interference signals. Furthermore, we introduce a new approach for updating the estimator through the use of staggered estimate. The goal of staggered estimation is to minimize the total number of estimates/calculations done within a time period while ensuring that there is no estimator aliasing. Finally, the proposed algorithm is implemented on an TMS320C6713 DSP Kit and an experimental verification is obtained. Copyright © 2009 John Wiley & Sons, Ltd.