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Titanium-Niobium (TiNb) alloys are commonly employed in a number of implantable devices, yet concerns exist regarding their use in implantology owing to the biomechanical mismatch between the implant and the host tissue. Therefore, to balance the mechanical performance of the load-bearing implant with bone, TiNb alloys with differing porosities were fabricated by powder metallurgy combined with spacer material. Microstructures and phase constituents were characterized with energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The mechanical properties were tested by uniaxial compression, and the corrosion performance was determined via a potentiodynamic polarization experiment. To evaluate a highly matched potential implant with the host, biocompatibilities such as cell viability and proliferation rate, fibronectin adsorption, plasmid-DNA interaction, and an SEM micrograph showing the cell morphology were examined in detail. The results showed that the alloys displayed open and closed pores with a uniform pore size and distribution, which allowed for cell adherence and other cellular activities. The alloys with low porosity displayed compressive strength between 618 MPa and 1295 MPa, while the alloys with high porosity showed significantly lower strength, ranging from 48 MPa to 331 MPa. The biological evaluation of the alloys demonstrated good cell attachment and proliferation rates. [ABSTRACT FROM AUTHOR]

Titanium-Niobium (TiNb) alloys are commonly employed in a number of implantable devices, yet concerns exist regarding their use in implantology owing to the biomechanical mismatch between the implant and the host tissue. Therefore, to balance the mechanical performance of the load-bearing implant with bone, TiNb alloys with differing porosities were fabricated by powder metallurgy combined with spacer material. Microstructures and phase constituents were characterized with energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The mechanical properties were tested by uniaxial compression, and the corrosion performance was determined via a potentiodynamic polarization experiment. To evaluate a highly matched potential implant with the host, biocompatibilities such as cell viability and proliferation rate, fibronectin adsorption, plasmid-DNA interaction, and an SEM micrograph showing the cell morphology were examined in detail. The results showed that the alloys displayed open and closed pores with a uniform pore size and distribution, which allowed for cell adherence and other cellular activities. The alloys with low porosity displayed compressive strength between 618 MPa and 1295 MPa, while the alloys with high porosity showed significantly lower strength, ranging from 48 MPa to 331 MPa. The biological evaluation of the alloys demonstrated good cell attachment and proliferation rates.

In quest of finding a sustainable solution for metal-free counter electrode materials, reduced graphene oxide (rGO) is emerged as the best alternative due to its intrinsic high electrocatalytic activity. However, owing to its two-dimensional sheets like structure, there is re-stacking of rGO sheets, which reduces exposed surface area and hinders in electrolyte diffusion. To avoid these issues, activated charcoal (AC) is explored as an active spacer material between rGO sheets, for the first time. By loading an optimum concentration of AC in rGO, a high porosity, high conductivity, and high concentration of active sites were gathered in the single composite structure. Such synchronized features of the proposed composite were utilized for Pt-free counter electrode application in dye-sensitized solar cell (DSSc). The composite structure showed high electrocatalytic activity, with a low charge transfer resistance of 0.7 Ω, which is far lower than Pt and rGO (8.5 Ω and 7.5 Ω). The DSSc fabricated with optimized composite showed power conversion efficiency of 8.6%, compared to Pt-based DSSc with 7.9% efficiency. Additionally, the potential of the electrode was also tested for the electro-photocatalytic (99%) degradation of methylene blue dye from water, in 60 min. The proposed highly efficient nanocomposite structure possesses the highest efficiency as compared to other previously studied rGO based counter-electrodes. Image 1 • Activated charcoal is explored as an active spacer material for rGO sheets. • Composite structure showed a power conversion efficiency of 8.6%. • Low charge transfer resistance of 0.45 Ω was observed, in the porous structure. • The proposed electrode electro-photocatalytically degraded 99% methylene blue dye. [ABSTRACT FROM AUTHOR]

In this article, a 5-nm node two-stack nanosheet FET with a triple-k spacer structure representing three spacer regions consisting of two inner spacers (inner spacer 1 and inner spacer 2) formed by two atomic layer deposition (ALD) processes leveraging the inner spacer formation-process method and outer spacer process of stack gate-all-around (GAA) process is proposed. Material and structure optimization was performed to confirm the effects of each spacer regions. Inner spacer 1 has a direct effect on the channel extension region. However, the inner spacer 2 is not in direct contact with the channel extension region and the gate, thus confirming the relatively indirect effect. In addition, the material dependence of the outer spacer, formed between the gate and the side region of the channel where the field is concentrated, was confirmed. By comparing the optimized triple-k spacer structure with the fully nitride spacer, the improved dynamic performance, as well as the active power and static power, was identified. [ABSTRACT FROM AUTHOR]

Recently, feed spacer research for improving the performance of a membrane module has adopted three-dimensional (3D) printing technology. This study aims to improve the performance of membrane feed spacers by using various materials and incorporating 3D printing. The samples were fabricated after modeling with 3D computer-aided design (CAD) software to investigate the mechanical strength, water flux, reverse solute flux, and fouling performances. This research was performed using acrylonitrile butadiene styrene (ABS), polypropylene (PP), and natural polylactic acid (PLA) as printing material, and the spacer model was produced using a diamond-shaped feed spacer, with a commercially available product as a reference. The 3D printed samples were initially compared in terms of size and precision with the 3D CAD model, and deviations were observed between the products and the CAD model. Then, the spacers were tested in terms of mechanical strength, water flux, reverse solute flux, and fouling (alginate-based waste water was used as a model foulant). Although there was not much difference among the samples regarding the water flux, better performances than the commercial product were obtained for reverse solute flux and fouling resistance. When comparing the prominent performance of natural PLA with the commercial product, PLA was found to have approximately 10% less fouling (based on foulant volume per unit area and root mean square roughness values), although it showed similar water flux. Thus, another approach has been introduced for using bio-degradable materials for membrane spacers. [ABSTRACT FROM AUTHOR]

The effect of three-layer weft knitted spacer material content and structure upon the characteristics of uniaxial tension, biaxial punching before and after fatigue punching, and at multi cycle low-stress (wearing level) punching were investigated. Three different spacer structures were knitted using four types of the same 20 tex linear density spun yarns. For three-layer weft knitted samples, innovative fibers, which are used in the production of functional clothing, were selected: Coolplus® 100% polyester (PES); Trevira CS® 100% PES; 60% PES; 40%PES, 60% PES with 0.02% carbon fiber and 67% cotton, 33% PES with 0.02% carbon fiber. It was defined that the samples, which have a plain jersey knitting pattern in the face and back layers, and a similar position of spacer yarns on the dial and cylinder needles, have the highest values of mass per unit area, but 1 × 1 tuck stitches in the face layer have a greater effect for material thickness. Besides, 1 × 1 tuck stitches in the face layer have a greater effect upon the uniaxial behavior and anisotropy of three-layer weft knitted spacer materials than on spacer yarn position in the connecting layer. The investigations of biaxial fatigue punching up to 50 N, which corresponds to wearing conditions, showed that the most stable and less deformable materials were the three-layer weft knitted spacer materials with a plain jersey knitting pattern in the face and back layers and a similar position of spacer yarns on the dial and cylinder needles. They also were characterized by the highest mass per unit area and medium thickness. [ABSTRACT FROM AUTHOR]

Abstract: Bipolar designs for a direct methanol fuel cell (DMFC) with liquid electrolyte have been investigated, aiming at a reduction of methanol crossover. A “spacer” (separator) material has to be applied which is inert in a sulphuric acid/methanol surrounding. This material has to be porous so that the liquid electrolyte can be pumped through. Swelling characteristics as well as variation of material properties with temperature and pressure have been investigated with several materials. It is essential to minimize the internal cell resistance in order to achieve a good performance of the DMFC. Due to the importance of electrolyte canal thickness with respect to ohmic resistance of the cell assembly, the variation of cell power output with electrolyte canal thickness was investigated. [Copyright &y& Elsevier]