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In the past few years, research on the fabrication of deep eutectic solvents (DESs)-based supported liquid membranes (SLMs) is increasing tremendously due to their significant advantages such as low mass transport resistance, high performance, easy scale-up, low cost and simple operation. However, fabrication of DES-based SLMs is challenging and highly dependent on the fabrication parameters: DES properties and properties of membrane supports. Subsequently, the fabrication methods, immersion, pressure-based impregnation and vacuum filtration also affect the permeation performance of DES-based SLMs in liquids and gases separation. Furthermore, the SLM durability is influenced by the DES properties and process parameters including: temperature, pressure, and feed composition. Firstly, present work reviews the current progress and fabrication of DES-based SLMs. Subsequently, it presents a perspective on different strategies that use DESs as a unique tunable platform to design advanced SLMs for liquids and gases separation reported in the literature. In the next step, performances of the SLMs membranes for liquids and gases separation are described in details. The effects of process parameters on DES-based SLMs are also highlighted prior to the challenges. Lastly, challenges and future research opportunities are highlighted. [ABSTRACT FROM AUTHOR]

Carbon-Dots (C-Dots) have drawn much attention in recent years owing to their remarkable properties such as high biocompatibility, low toxicity, nano-scale size, and ease of modification with good tuneable photoluminescence performance. These unique properties have led C-Dots to become a promising platform for bioimaging, metal ion sensing and an antibacterial agent. C-Dots can be prepared using the top-down and bottom-up approaches, in which the latter method is commonly used for large scale and low-cost synthesis. C-Dots can be synthesized using sustainable raw materials or green biomass since it is environmentally friendly, in-expensive and most importantly, promotes the minimization of waste production. However, using biomass waste to produce high-quality C-Dots is still a matter of concern waiting for resolution, and this will be the main focus of this review. Fundamental understanding of C-Dots such as structure analysis, physical and chemical properties of C-Dots, various synthesis methodology and type of raw materials used are also discussed and correlated comprehensively. Additionally, factors affecting the bandgap of the C-Dots and the strategies to overcome these shortcomings are also covered. Moreover, formation mechanism of C-Dots focusing on the hydrothermal method, option and challenges to scale up the C-Dots production are explored. It is expected that the great potential of producing C-Dots from agricultural waste a key benefit in view of their versatility in a wide range of applications.

Laser-induced graphene (LIG) has emerged as a promising electrode material for electrochemical point-of-care diagnostics. LIG offers a large specific surface area and excellent electron transfer at low-cost in a binder-free and rapid fabrication process that lends itself well to mass production outside of the cleanroom. Various LIG micromorphologies can be generated when altering the energy input parameters, and it was investigated here which impact this has on their electroanalytical characteristics and performance. Energy input is well controlled by the laser power, scribing speed, and laser pulse density. Once the threshold of required energy input is reached a broad spectrum of conditions leads to LIG with micromorphologies ranging from delicate irregular brush structures obtained at fast, high energy input, to smoother and more wall like albeit still porous materials. Only a fraction of these LIG structures provided high conductance which is required for appropriate electroanalytical performance. Here, it was found that low, frequent energy input provided the best electroanalytical material, i.e., low levels of power and speed in combination with high spatial pulse density. For example, the sensitivity for the reduction of K3[Fe(CN)6] was increased almost 2-fold by changing fabrication parameters from 60% power and 100% speed to 1% power and 10% speed. These general findings can be translated to any LIG fabrication process independent of devices used. The simple fabrication process of LIG electrodes, their good electroanalytical performance as demonstrated here with a variety of (bio)analytically relevant molecules including ascorbic acid, dopamine, uric acid, p-nitrophenol, and paracetamol, and possible application to biological samples make them ideal and inexpensive transducers for electrochemical (bio)sensors, with the potential to replace the screen-printed systems currently dominating in on-site sensors used. [ABSTRACT FROM AUTHOR]

Two-step foaming (TSF) method is one of cost-effective ways to prepare shaped, closed-cell Al alloy foams with a thick surface layer, which can provide good energy absorption property. In this study, we designed 27 groups orthogonal experiments based on Taguchi method to investigate the effects of key processing parameters on the closed cellular structure of AlCu alloy foams fabricated via the TSF method. The compressive behavior and energy absorption of the fabricated foams were also evaluated and compared with samples prepared by powder metallurgy method (PM). The results showed that processing parameters such as the holding time, foaming temperature and their mutual interaction during the second foaming could affect the final cellular structure features, such as porosity content, average diameter, pore distribution uniformity and sphericity. Quantitative analysis indicated that a shorter holding time (760 °C) could fabricate AlCu alloy foams with descent cellular structure and energy absorption capability.

A systematic optimization of several parameters significant in the fabrication of anode-supported micro-tubular solid oxide fuel cell via extrusion and dip coating is presented in this study. Co-sintering temperature of anode-support and electrolyte, the vehicle type and solid powder content used in electrolyte dip-coating slurry, electrolyte submersion time, cathode sintering temperature, powder ratio in the cathode functional layer, submersion time for the cathode functional layer and, submersion time and coating number of the anode functional layer are studied in this respect and optimized in the given order according to the performance tests and microstructural analyses. The performance of the micro-tubular cell is significantly improved to 0.49 Wcm−2 at 800 °C after the optimizations, while that of the base cell is only 0.136 Wcm−2. 12-cell micro-tubular stack is also constructed with the optimized cells and the stack is tested. Each cell in the stack is found to show very close performance to the single-cell performance and the stack with a maximum power of ~26 W at an operating temperature of 800 °C is therefore evaluated to be successful. • Micro-tubular solid oxide fuel cells are fabricated via extrusion and dip coating. • A systematic optimization of several fabrication parameters is presented. • Cell performance at 800 °C is improved to 0.49 Wcm−2 from 0.136 Wcm−2. • 12-cell micro-tubular SOFC stack is also constructed with the optimized cells. • Each cell in the stack shows very close performance to the single-cell performance. [ABSTRACT FROM AUTHOR]

Hollow fiber membranes (HFMs) possess desired properties such as high surface area, desirable filtration efficiency, high packing density relative to other configurations. Nevertheless, they are often possible to break or damage during the high-pressure cleaning and aeration process. Recently, using the braid reinforcing as support is recommended to improve the mechanical strength of HFMs. The braid hollow fiber membrane (BHFM) is capable apply under higher pressure conditions. This review investigates the fabrication parameters and the methods for the improvement of BHFM performance.

Copyright of Journal of Polytechnic is the property of Journal of Polytechnic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The temperature-sensitive performance of a microfiber coil resonator (MCR) is thoroughly investigated. The MCR is fabricated by wrapping a microfiber on a PMMA rod coated with a UV-curable low refractive index epoxy. The temperature sensitivity is measured by investigating the correlation between the shift of the resonant wavelength and the surrounding temperature. It is determined that a range of parameters of the MCRs, including the gap between two adjacent rings, the diameter of the supporting rod, the number of rings, and the diameter of the microfiber, have a great influence on the temperature sensitivity of the MCRs. By optimizing the fabrication parameters of MCRs, such as the gap of the adjacent microrings and the diameter of supporting rod, etc., the maximum temperature sensitivity obtained is 237.31 pm/°C, which is about 2.3 times higher than that of MCR embedded in EFIRON UV-373 polymer and 23 times higher than that of MCR embedded in Teflon because of the strong thermo-optic and thermal expansion effects of the low refractive index epoxy and the supporting rod used in the experiments. Theoretical (numerical) simulation and experiment results are considered in the assessment of the optical performance improvement of MCR-based optical fiber temperature sensors. [ABSTRACT FROM AUTHOR]

In order to reveal the distortion mechanism of PLA part, the bilinear elastic-softened cohesive model is adopted and the micromechanics is utilized for the first time to describe the interface state. The residual stress models of the elastic interface state, elastic-softened state, and the elastic-softened-de-bonding interface state are established quantitatively according to the cohesive zone model to investigate the relationship between building parameters and residual stress, respectively. An experimental is proposed to validate the theoretical residual models. The experimental results indicate that the layer thickness plays the dominant role in determining the distortion compared with deposition velocity. The distortion of PLA part is mainly caused by accumulation of residual stresses resulting from non-uniform temperature gradients in continuous heating and cooling cycles. The temperature of the filament with different building parameters in the fabrication process is collected to observe the relationship between part distortion and temperature and the temperature files show a good accordance with the distortion trend. The qualitative analyzed results of the residual stress models also coincide with the experimental results well, which indicates the effectiveness of the residual stress model and shows that it can express the distortion mechanism well. [ABSTRACT FROM AUTHOR]

A multi-photon absorption-based laser writing system with sub-micrometer resolution has been developed using an inexpensive sub-nanosecond laser for two- and three-dimensional structuring in photosensitive resist materials. New combinations of commercially available photoresists such as SU-8 and AR-N 4340, and a photo-initiator (2, 4, diethyl-9H-thioxanten-9-one) with large two-photon absorption at 532 nm are shown to be effective in obtaining sub-micrometer line or dot resolution. Systematic studies of the resolution on the system and fabrication parameters such as laser power, writing speed, focusing arrangement, etc. have been carried out. The sub-nanosecond-based laser micro writer is an inexpensive alternative with similar capabilities as a femtosecond-based laser writer. This system is comparably effective and has much higher capabilities for 2D structuring in terms of the aspect ratio of the fabricated structures than conventional 2D laser micro writers. [ABSTRACT FROM AUTHOR]

AgSbTe bulk sample is obtained by hot-pressing under different fabrication parameters, and their thermoelectric properties are investigated in the temperature range of 300 - 550 K. The highest ZT = 0.86 is achieved at 475 K for the sample hot-pressed at 423 K and 500MPa due to the lower thermal conductivity and higher power factor. The results indicate that the optimized thermoelectric properties can be obtained for AgSbTe compound at the sintering temperature of 423 K under the pressure of 500 MPa. [ABSTRACT FROM AUTHOR]

In this study, a full factorial approach was used to investigate the effects of poly(ethylene glycol) (PEG) molecular weight (MW; 10,000 vs. 35,000 nominal MW), crosslinker-to-macromer carbon-carbon double bond ratio (DBR; 40 vs. 60), crosslinker type (PEG-diacrylate (PEGDA) vs. N, N′-methylene bisacrylamide (MB)), crosslinking extent of incorporated gelatin microparticles (low vs. high), and incubation medium composition (with or without collagenase) on the swelling and degradation characteristics of oligo[(poly(ethylene glycol) fumarate)] (OPF) hydrogel composites as indicated by the swelling ratio and the percentage of mass remaining, respectively. Each factor consisted of two levels, which were selected based on previous in vitro and in vivo studies utilizing these hydrogels for various tissue engineering applications. Fractional factorial analyses of the main effects indicated that the mean swelling ratio and the mean percentage of mass remaining of OPF composite hydrogels were significantly affected by every factor. In particular, increasing the PEG chain MW of OPF macromers significantly increased the mean swelling ratio and decreased the mean percentage of mass remaining by 5.7 ± 0.3 and 17.2 ± 0.6%, respectively. However, changing the crosslinker from MB to PEGDA reduced the mean swelling ratio and increased the mean percentage of mass remaining of OPF composite hydrogels by 4.9 ± 0.2 and 9.4 ± 0.9%, respectively. Additionally, it was found that the swelling characteristics of hydrogels fabricated with higher PEG chain MW or with MB were more sensitive to increases in DBR. Collectively, the main and cross effects observed between factors enables informed tuning of the swelling and degradation properties of OPF-based hydrogels for various tissue engineering applications. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3477-3487, 2014. [ABSTRACT FROM AUTHOR]

In this paper, the effect of fabrication parameters on the pore concentration of aluminum metal foam manufactured by powder metallurgy process is studied. Aluminum metal foam specimens were fabricated from the mixture of aluminum powders (mean particle size 60 μm) and NaCl at 10,20,30,40(wt) % content under 200, 250, 300, MPa Pressures. All specimens were then sintered at 630°C for 2.5 hours in an argon atmosphere. For pore formation (foaming), sintered specimens were immersed into 70°C hot running water. Finally the pore concentration of specimens was recorded to analyze the effect of fabrication parameters (namely NaCl ratio, NaCl particle size and compacting pressure) on the foaming behavior of compacted specimens. As a result of the study, it has been recorded that the above mentioned fabrication parameters are effective on pore concentration profile while pore diameters remained unchanged. [ABSTRACT FROM AUTHOR]

In this work, the effect of fabrication parameters on the pore concentration of aluminum metal foam, manufactured by the powder metallurgy process, has been studied. The artificial neural network (ANN) technique has been used to predict pore concentration as a function of some key fabrication parameters. Aluminum metal foam specimens were fabricated from a mixture of aluminum powders (mean particle size 60 μm) and NaCl at 10, 20, 30, 40(wt)% content under a pressure of 200, 250, and 300 MPa. All specimens were then sintered at 630°C for 2.5 h in argon atmosphere. For pore formation (foaming), sintered specimens were immersed into 70°C hot running water. Finally, the pore concentration of specimens was recorded to analyze the effect of fabrication parameters (namely, NaCl ratio, NaCl particle size, and compacting pressure) on the foaming behavior of compacted specimens. It has been recorded that the above-mentioned fabrication parameters are effective on pore concentration profile while pore diameters remain unchanged. In the ANN training module, NaCl content (wt)%, NaCl particle size (μm), and compacting pressure (MPA) were employed as inputs, while pore concentration % (volume) of compacts related to fabrication parameters was employed as output. The ANN program was successfully used to predict the pore concentration % (volume) of compacts related to fabrication parameters. [ABSTRACT FROM AUTHOR]

Copyright of Teknoloji is the property of Engineering Science & Technology, an International Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: CuAlO2 thin films have been grown on glass substrates using spray technique; a low-cost method of thin films depositing. The deposition was carried out in a 450–525°C range of substrate temperature. The solution and gas flow rates were kept constant at 5cm3 min−1 and 6.10−3 m3 min−1, respectively. Compressed air was used as a carrier gas. The structural, morphological and optical properties of these thin films have been studied. These properties are strongly related to the substrate temperature and to the [Cu]/[Al] molar ratio r. X-ray diffraction analysis confirmed the initial amorphous nature of as-deposited films and phase transition into crystalline CuAlO2 with the preferential orientation (101) upon annealing at 570°C. The optical transmission of 80% has been achieved in the visible spectrum. CuAlO2 band gap energy in the range of 3.34–3.87eV has been found by optical measurement depending on fabrication parameters. [Copyright &y& Elsevier]

We developed a statistical Monte Carlo technique for the performance estimation of optical microelectromechanical systems (MEMS) components taking into account the randomness nature of its assembly. The developed technique is applied on the 2×2 moving mirror optical MEMS switch as a typical example to study its performance under realistic passive-alignment conditions. The obtained results enable us to evaluate the assembly process capability and to analyze the performance sensitivity to different fabrication parameters. This enables us to establish a design for manufacturability technique for the optical MEMS components. [ABSTRACT FROM PUBLISHER]

Plate products of thickness 0.25–26 mm were evaluated, for the reference V–4Cr–4Ti alloy (NIFS-HEATs), from the viewpoint of recrystallized grain structure, precipitate distribution and fracture behavior at low temperature. 6.6 mm-thick or thinner plates showed relatively homogeneous and fine grain structure, and ductile fracture behavior. For 26 mm-thick plate, however, coarsened grain structure and localized distribution of precipitate clusters suggested that further hot working should be necessary to obtain the similar properties to those of the thinner plates. Grain structure, precipitate distribution, and anisotropy of fracture mode were shown to be influenced deeply by working and heating history at breakdown processes of the ingot. From the results the optimum fabrication parameters for vanadium alloys are discussed. [Copyright &y& Elsevier]

A study of Mach-Zehnder interferometer (MZI) modulators using unetched and etched Ti:LiNbO3 waveguides has been made. A full vectorial finite-element-based mode solver was used, followed by a finite element-based solution of the Laplace equation to calculate the electrooptic effect and, subsequently, the half-wave voltage, Vπ The optical loss due to the metal electrodes was also found using the H-field finite-element method (FEM) incorporating the perturbation method. The microwave effective index, nm, and the characteristic impedance of the metal electrodes, Zc, were also found for a number of electrode thicknesses and ridge heights. A semivectorial finite-element beam propagation method (SVFEBPM) was used to estimate the radiation loss for the curved input and output (I/O) waveguides of the MZI. The device characteristics were then studied by making changes to a number of fabrication parameters, of which the two most important were found to be the etch depth of the ridge and the thickness of the SiO2 buffer layer. [ABSTRACT FROM PUBLISHER]

Hollow fiber membranes (HFMs) possess desired properties such as high surface area, desirable filtration efficiency, high packing density relative to other configurations. Nevertheless, they are often possible to break or damage during the high-pressure cleaning and aeration process. Recently, using the braid reinforcing as support is recommended to improve the mechanical strength of HFMs. The braid hollow fiber membrane (BHFM) is capable apply under higher pressure conditions. This review investigates the fabrication parameters and the methods for the improvement of BHFM performance. [ABSTRACT FROM AUTHOR]

A novel self-aligned fabrication process for LiNbO3:Ni ridge waveguides has been proposed. By using the self-aligned trilayered structure composed of Ni-Ti-Si, the fabrication process is significantly simplified, and takes advantage of suppression of the unwanted planar waveguides and high-coupling efficiency to a single-mode fiber as compared to the conventional processes. Detailed investigations into the characteristics of the ridge waveguides have also proved to be informative under different fabrication parameters. Moreover, the novel self-aligned fabrication process was applied to fabricate a ridge waveguide Mach-Zehnder modulator. The measured half-wave voltage and extinction ratio mere 20.5 V and 12 dB (@1.3 μm), and were 4.2 V and 8 dB (@0.6328 £gm) [ABSTRACT FROM PUBLISHER]

An optical waveguide is described that has a hollow arch-shaped core. Optical confinement for this structure is based on the antiresonant reflecting optical waveguide principle. The waveguides are built on a silicon substrate using a sacrificial etch technique with reflowed photoresist serving as the sacrificial material and producing the core's arch shape. Investigations of fabrication parameters are reported that allow for predicting a final arch-shaped geometry based on initial photoresist width and thickness. Optical mode guiding is demonstrated in an arch-shaped waveguide with a liquid core. [ABSTRACT FROM PUBLISHER]