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Scaling up of microbial fuel cells is a challenge for practical applications in wastewater treatment. In addition, the flow control is an important aspect for the electrochemical reactions occurring at the electrodes are influenced by fluid motions. By using dimensionless parameter analysis fluid regimes can be investigated in different scales of reactors. In this study, four important dimensionless flow parameters such as Reynolds number, Peclet number, Schmidt number, and Sherwood number were used for systematic analysis of hydrodynamic effects and power performance of recirculation mode microbial fuel cells together with computational fluid dynamics method. Results showed that the higher value of Reynolds number enhanced the convective flow of anolyte due to the dominant inertial forces in the flow field. Therefore, Reynolds number of 1.6 × 101 were obtained high mass transfer coefficient of 4.76 × 10−7 m s-1 and thin diffusion layer thickness of 2.52 × 10-3 m. Maximum power density and limited current density of 2422.8 mW m-2 and 4736.4 mA m-2 were obtained respectively which were higher than Reynolds number of 0 by 1.61 and 1.69 times. These findings shall be useful for effective recirculation flow mode MFCs power production and have a great possibility for large scale applications.

A facile wet-impregnation process is employed to prepare ultrafine SnO2 nanoparticles that are confined in three dimensional interpenetrating cubic ordered mesoporous carbon. The nanocomposite that is composed of SnO2 and ordered mesoporous carbon serves as a promising anode in lithium-ion batteries. Successful confinement and crystallization of SnO2 nanoparticles are confirmed by a variety of characterization techniques including nitrogen adsorption-desorption isotherms, X-ray diffraction, selected area electron diffraction patterns and transmission electron microscopy. The nanocomposite anode delivers an initial reversible capacity of 1093 mA h g−1 with capacity retention of 66 and 57% after 100 and 500 cycles, respectively, and Coulombic efficiency value of over 99%, excluding a few initial cycles at a high current density of 780 mA g−1. The nanocomposite anode exhibits remarkable performance with discharge capacities of 1282 and 947 mA h g−1 after 2nd and 130 cycles, respectively, at a current density of 200 mA g−1. When higher current densities of 1600 and 4000 mA g−1 are employed to the cell, satisfactory reversible capacities of 529 and 228 mA h g−1, respectively, are obtained. The remarkable capacity, rate capability and cycling stability of nanocomposite anode demonstrate its great potential for use in high-performance lithium-ion batteries.

Microbial fuel cell (MFC) technology is being given immense esteem in the scientific community for its capability of transforming organic waste directly into electricity through electrochemical reactions occurring at the microbial catalyzed anode, and microbial or abiotic cathode The microbes in a MFC transfer the electrons to the electrode through various electron transfer mechanisms and among them, nanowire transfer mechanism is the most significant one. The purpose of this study was to design and develop mathematical models for predicting the nanowire electron transfer mechanism. Results obtained from the experiments and simulations are found to be well in agreement with each other. These evidences prove that electron transfer mechanisms do occur in the microbial biofilm of the MFCs. In addition, these results imply that the f electron transfer mechanism may lead to an increase in power generation from the MFC. Biofilms with thicknesses of 2 μm and 1 μm have enhanced a current density increase of 86% and 73% respectively than that of 3 μm thick biofilms. Thus, it was observed that the biofilm thickness had a very less influence on the performance of MFC and these results can contribute to the development of MFC in the field of energy generation.

This study developed a tubular solid oxide fuel cell (SOFC) anode support layer via atmospheric plasma spraying, which is considered one of the most promising methods for producing SOFCs because of its faster deposition rate and lower cost compared with other film formation processes. Plasma spraying can replace the traditional use of extrusion technology to manufacture the anode base tube, eliminating the need for high-temperature sintering steps. In this study, commercially available powders were used to make the anode of a tubular SOFC from NiO/yttria-stabilized zirconia (YSZ) powder, and Na2CO3 and polymethyl methacrylate were tested as pore-forming agents. The anode composite powder was sprayed on the graphite base pipe, and the final product was changed by altering the spraying parameters and anode powder ratio. The direct current (DC) resistance measurements showed that the conductivity of the Ni/YSZ tubular anode formed with higher power plasma spraying could reach 428.55 S/cm at 800 °C. The experimental results showed that the power and parameters of atmospheric plasma spraying could affect the porosity and electron conductivity of tubular SOFC anodes.

Hydroxyapatite (HA) has good biocompatibility, high strength and low fracture toughness. It is often used as the main material for artificial bones in bioceramics because of the similar composition. In this study, we prepared zinc-doped hydroxyapatite by the co-precipitation method to produce artificial bone material has antibacterial properties, for use in post joint surgery to inhibit bacterial infection or proliferation and ultimately the incidence of osteomyelitis. The co-precipitation method prepared hydroxyapatite with different concentrations of zinc chloride. The experimental results revealed that after sintering, it has some new phases generated of ZnO and CaZn2(PO4)2 when we add zinc chloride that concentration reaches 0.15 M. The minimum inhibition zone revealed the antibacterial ability of Zinc-HA increased when the concentration of zinc chloride increased from 0.0125 M to 0.15 M. The granulated powder of zinc-doped hydroxyapatite was coated on the titanium substrate by the flame-spraying method. The Zinc-HA coating was found with good biocompatibility and antibacterial ability in the biological and antibacterial test.

This study aims to fabricate a porous anode coating for solid oxide fuel cells (SOFC) by the flame spraying. Flame spraying is an easy low-temperature process and offers the advantage of a reduced thermal stress. Due to the low-temperature, the initial selection of the feedstock will affect the deposition of the coating. In this study, two kinds of feedstocks were used. One was the commonly used NiO/8YSZ for anode fabrication. The second was the Ni metal with 8YSZ design for the low temperature flame spray. The special nickel-coated graphite (NiGr) was employed as the pore former. The results show that NiO/8YSZ forms a uniform and flat coating with small-sized pores. The Ni/8YSZ powder forms a rough coating containing large-scale pores. The addition of NiGr into the composite powder increases the porosity and permeability of the anode after graphite burn out and hydrogen reduction. In summary, the use of a Ni/8YSZ/NiGr feedstock yields higher porosity (35–40%), gas permeability (1.37 Darcy), bonding strength (45.6 ± 3.18 MPa) and better anode conductivity.

The purpose of this study is to develop macroporous TCP (tricalcium phosphate) with irregular shape and the use of HA (hyaluronic acid) gel as the lubricating agent of a composite hydrogel for cell carrier. The porous TCP particle with meteorite shape was made by the solid-state reaction by adding different ratios of the PMMA (Poly(methyl methacrylate)). The subcutaneous filler was made by mixing hyaluronic acid gel with TCP particles and live cells. For the in vitro testing, the mouse fibroblasts cell line L929 was employed for analysis of the toxicity and biocompatibility of the material. The cells were cultured on the material for one to three days followed by the WST-1 (Water soluble tetrazolium) and LDH (Lactate dehydrogenase) analysis. The results of LDH and WST-1 showed that the composite HA/β-TCP was not cytotoxicity. The advantage of this product is the meteorite shaped macroporous TCP particle in the hyaluronic acid gel that could form a linkage channel in the gel. When the fat cell mixed with the composite HA/TCP gel, the fat cells will not be covered with the hyaluronic acid for a long time, and hence the cell will not die of hypoxia or the lack of growth factors provided by the subject’s body fluid. As the proliferation of fat cells progressed, it became a good filler of the injected area.

Cubic FDU-12 type mesoporous silicas with enlarged pores and carboxylic acid (–COOH) functionality in the pore channels (denoted as LP-FTC-x) are synthesized using tetraethyl orthosilicate (TEOS) and carboxyethylsilanetriol sodium salt (CES) as silica sources, Pluronic F127 triblock copolymer as template, and trimethylbenzene (TMB) as pore expander, and utilized them as supports for enzyme immobilization. When the –COOH content is increased from 0 to 30%, the pore size of LP-FTC-x decreases from 23.6 to 11.1 nm, and its particle size decreases from around 2 μm to 600–800 nm. The material exhibits a high papain adsorption capacity (895 mg g−1) with a low leaching rate at pH 8.2 due to the well-defined surface chemistry in the pore channel. The adsorption kinetics and isotherms follow the pseudo-second-order model and the Langmuir isotherm model, respectively. The excellent structural properties of LP-FTC-x are also advantageous for enhancement in stability of enzyme toward the temperature, solution pH, and incubation time variations.

Cubic mesoporous silica SBA-1 functionalized with carboxylic acid (-COOH), namely S1B-C10, is used as a support to fabricate and confine Ru nanoparticles (NPs). The uniformly dispersed organic functional groups in SBA-1 are beneficial in attracting Ru cations, and as a result, homogenously distributed small sized Ru NPs are formed within the mesopores. The prepared Ru@S1B-C10 is utilized as a catalyst for H2 generation from the hydrolysis of ammonia borane (AB). The Ru@S1B-C10 catalyst demonstrates high catalytic activity for H2 generation (202 mol H2 molRu min−1) and lower activation energy (24.13 kJ mol−1) due to the small sized Ru NPs with high dispersion and the support’s interconnected mesoporous structure. The nanosized Ru particles provide abundant active sites for the catalytic reaction to take place, while the interconnected porous support facilitates homogenous transference and easy dispersal of AB molecules to the active sites. The catalyst demonstrates good recycle ability since the accumulation and leaking of NPs throughout catalysis can be effectively prevented by the support.

Hydrodynamic boundary layer is a significant phenomenon occurring in a flow through a bluff body, and this includes the flow motion and mass transfer. Thus, it could affect the biofilm formation and the mass transfer of substrates in microbial fuel cells (MFCs). Therefore, understanding the role of hydrodynamic boundary layer thicknesses in MFCs is truly important. In this study, three hydrodynamic boundary layers of thickness 1.6, 4.1, and 5 cm were applied to the recirculation mode membrane-less MFC to investigate the electricity production performance. The results showed that the thin hydrodynamic boundary could enhance the voltage output of MFC due to the strong shear rate effect. Thus, a maximum voltage of 22 mV was obtained in the MFC with a hydrodynamic boundary layer thickness of 1.6 cm, and this voltage output obtained was 11 times higher than that of MFC with 5 cm hydrodynamic boundary layer thickness. Moreover, the charge transfer resistance of anode decreased with decreasing hydrodynamic boundary layer thickness. The charge transfer resistance of MFC with hydrodynamic boundary layer of thickness 1.6 cm was 39 Ω, which was 0.79 times lesser than that of MFC with 5 cm thickness. These observations would be useful for enhancing the performance of recirculation mode MFCs.

This study synthesized spinel LiMn 2 O 4 materials using a solid-state reaction processing technology. Neutral surfactants and the tri-block copolymer P123 (template) formed an organic self-assembly in alcohol (solvent), with LiCH 3 COO·2H 2 O and Mn(CH 3 COO) 2 ·4H 2 O as precursors of the inorganic skeleton. Changes in the structure, particle size, and surface area of LiMn 2 O 4 powder in relation to different surfactant contents were investigated. The changes in surface area should affect the wetting effect of the electrolyte on the cathode material, thereby further influencing the actual reaction area and charge–discharge efficiency. The results were analyzed to assess the effect of surface area on electrochemical performance of LiMn 2 O 4 cathode materials. X-ray diffraction (XRD) analysis data showed that LiMn 2 O 4 materials synthesized through the solid-phase reaction method are single-phase spinel, whose original structure is unaffected by the addition of surfactants. Scanning electron microscopic (SEM) observation revealed that LiMn 2 O 4 forms different spherical particles after the addition of different concentrations of surfactants. Furthermore, Brunauer–Emmett–Teller (BET) analysis showed that specific surface areas of 0.4–1.2 m 2 /g are relatively effective in enhancing the capacitance, similarly the formation of spherical particles is beneficial in enhancing the capacitance, and the high-current discharge efficiency is similar to the low-current discharge efficiency. As for the different concentrations of P123, the experiments added with 1.42 M P123 achieved optimum results.

In this study, a (La0.8Sr0.2)0.98MnO3 protective layer was prepared on the C276, Crofer22 APU, SUS304, and SUS430 alloys by the atmospheric plasma spraying technique (APS). The oxidation behavior and electrical property of these metal alloys have been investigated isothermally at 800 °C in air for up to 300 h. Results showed that the ferritic steels transform into MnCr2O4 spinels and a Cr2O3 layer during isothermal oxidation. The C276 alloy formed NiCr2O4 and FeCr2O4 layers; these are protective and act as an effective barrier against chromium migration into the outer oxide layer, and the alloy demonstrated good oxidation resistance and a reasonable match to the coefficient of thermal expansion of the substrate and a low-oxide scale area-specific resistance. The ASR effects on the formation of oxide scale have been investigated, and the ASR of coated samples was below 0.024 Ω·cm2. It has good electrical conductivity for SOFC in long-term use.

Radio frequency (RF) sputtering is a potential medical device coating technology that is commercializable; however, a suitable commercialized target for sputtering the hydroxyapatite (HA) coating onto titanium medical devices is more important. Therefore, this study used three HA targets in conducting sputtering experiments for HA films, which were manufactured in a laboratory by using three different processes: cold pressing and sintering (CPS), hot isostatic pressing (HIP), and atmospheric plasma spraying (APS). Subsequently, the sputtering performance of each type of target and the properties of the HA films were assessed to develop an appropriate process for modifying the surfaces of medical devices. The experimental results showed that the APS target, with a density of approximately 2.83 g/cm3, was suitable for use in HA sputtering. Additionally, the APS target could withstand a high discharge power over 300 W, whereas the CPS target could nearly endure a power below 70 W. The APS target, with Ca/P ratio of 2.401, consisted of a combination of HA, α-tricalcium phosphate (α-TCP), β-TCP, and tetracalcium phosphate phases (TTCP). In addition to being able to perform at a high sputtering power of more than 300 W, the APS target achieved a higher deposition rate than did the CPS target. This study shows that the processing technology used for the APS target is a potential method for applying HA sputtering for the surface modification of artificial aggregates.

Plasma-sprayed HA coating (HAC) 50 and 200 microm thick on Ti6Al4V cylinders was transcortically implanted in the femora of canines. Push-out testing of implant-bone interfaces showed that the HAC coating exhibited higher shear strength at 50 microm coating than 200 microm one. The plasma-sprayed HACs were exhibited compressive residual stresses and the thicker HAC exhibited higher residual stress than that of the thinner HAC. Due to the structure for 50 and 200 microm implants were the same, meaning similar cohesive strength of the lamellar splats. And, there was no difference in the physiological environment; hence the difference of the shear strength for the 50 and 200 microm-HAC implants could best be attributed to the compressive residual stress existed in the HA coating.

Copper is being considered for touch surfaces applications, such as bathroom accessories, because of their antimicrobial property, which can potentially reduce infection transmission. Since thermal passivation method is widely applied on surface of copper to produce color for decorative purpose, bathroom and toilet interior designers are interested in knowing the property of passivated copper surface in high humidity environment. The present study investigates the discoloration and antimicrobial property of a thermally passivated surface of copper against Escherichia coli (E. coli) bacteria. The spectral colorimeter analysis has been conducted to evaluate the degree of surface discoloration, XRD analysis has been conducted to identify the phases on the surface, a method based on JIS Z 2801: 2000 has been utilized to evaluate the colony forming unit (CFU) of E. coli on sample surface.

The improvement of electrode materials used in microbial fuel cell (MFC) technology for enhancing the power performance of MFCs has attracted more and more attention lately. In this study, an new electrode material with a carbon nanotube planted on an Ni-based alloy substrate is applied to the MFC. Results show that a well-synthesized, straight CNT electrode performs the best, with a high open circuit voltage of 0.82 V and a maximum power density of 2.31 W/m2. It is believed that this new kind of electrode will have a promising future in the technology of power generation from MFCs.

Can individual cells, including live cells, be imaged using hard x rays? Common wisdom until now required sophisticated staining techniques for this task. We show instead that individual cells and cell details can be detected in culture solution and tissues with no staining and no other contrast-enhancing preparation. The sample examined can be much thicker than for many other microscopy techniques without sacrificing the capability to resolve cells. The key factor in our approach is the use of a coherent synchrotron source and of contrast mechanisms based on the refractive index. The first successful tests were conducted on a variety of cell systems including skin and internal leaf cells, mouse neurons, rabbit fibroblast cells, and human tumor cells.