Foam Plates Research Articles

Pd-Pt loaded graphene aerogel on nickel foam composite as binder-free anode for a direct glucose fuel cell unit

Fabrication of electrocatalyst for direct glucose fuel cell (DGFC) operation involves destructive preparation methods with the use of stabilizer like binder, which may cause activity depreciation. Binder-free electrocatalytic electrode becomes a possible solution to the above problem. Binder-free bimetallic Pd-Pt loaded graphene aerogel on nickel foam plates with different Pd/Pt ratios (1:2.32, 1:1.62, and 1:0.98) are successfully fabricated through a green one-step mild reduction process producing a Pd-Pt/GO/nickel form plate (NFP) composite. Anode with the binder-free electrocatalysts exhibit a strong activity in a batch type DGFC unit under room temperature. The effects of glucose and KOH concentrations, and the Pd/Pt ratios of the electrocatalyst on the DGFC performance are also studied. Maximum power density output of 1.25 mW cm−2 is recorded with 0.5 M glucose/3 M KOH as the anodic fuel, and Pd1Pt0.98/GA/NFP as catalyst, which is the highest obtained so far among other types of electrocatalyst.

Optimization of a novel large field of view distortion phantom for MR-only treatment planning.

Purpose MR‐only treatment planning requires images of high geometric fidelity, particularly for large fields of view (FOV). However, the availability of large FOV distortion phantoms with analysis software is currently limited. This work sought to optimize a modular distortion phantom to accommodate multiple bore configurations and implement distortion characterization in a widely implementable solution.Method and MaterialsTo determine candidate materials, 1.0 T MR and CT images were acquired of twelve urethane foam samples of various densities and strengths. Samples were precision‐machined to accommodate 6 mm diameter paintballs used as landmarks. Final material candidates were selected by balancing strength, machinability, weight, and cost. Bore sizes and minimum aperture width resulting from couch position were tabulated from the literature (14 systems, 5 vendors). Bore geometry and couch position were simulated using MATLAB to generate machine‐specific models to optimize the phantom build. Previously developed software for distortion characterization was modified for several magnet geometries (1.0 T, 1.5 T, 3.0 T), compared against previously published 1.0 T results, and integrated into the 3D Slicer application platform.ResultsAll foam samples provided sufficient MR image contrast with paintball landmarks. Urethane foam (compressive strength ∼1000 psi, density ~20 lb/ft3) was selected for its accurate machinability and weight characteristics. For smaller bores, a phantom version with the following parameters was used: 15 foam plates, 55 × 55 × 37.5 cm3 (L×W×H), 5,082 landmarks, and weight ~30 kg. To accommodate > 70 cm wide bores, an extended build used 20 plates spanning 55 × 55 × 50 cm3 with 7,497 landmarks and weight ~44 kg. Distortion characterization software was implemented as an external module into 3D Slicer's plugin framework and results agreed with the literature.ConclusionThe design and implementation of a modular, extendable distortion phantom was optimized for several bore configurations. The phantom and analysis software will be available for multi‐institutional collaborations and cross‐validation trials to support MR‐only planning.

Durability tests of Rh/Al-Ce-Zr catalysts coated on NiCrAl metal foam for ATR of dodecane at high temperature

In this study, NiCrAl metal foam was used as the support material. Rh/Al-Ce-Zr-based catalysts were also used as a reforming catalyst, and was coated over a metal foam plate using a rotary vacuum evaporator. The Al-Ce-Zr-based catalytic support material coated over a metal foam plate exhibited a nano-structured morphology. XRD showed that the cerium and zirconium components in the Al-Ce-Zr-based catalytic support material were synthesized in the CeZrO2 crystal structure. CeZrO2 prevents carbon deposition on the catalyst active site due to their high lattice oxygen mobility. The composition of hydrogen by diesel auto-thermal reforming increased with increasing reaction temperature, and 6, 12, and 43% was obtained at 600, 700, and 800°C, respectively. The fuel conversions were 20, 85, and 100%. A long-term activity test of the Rh/Al-Ce-Zr-based catalyst was carried out under the optimal auto-thermal reforming conditions. The composition of hydrogen and carbon monoxide in the dry-product gas was maintained at approximately 45% and 11% during 500 h, respectively. Therefore, the catalytic activity of Rh/Al-Ce-Zr based catalysts for diesel auto-thermal reforming is excellent. The carbon content on the surface of the catalysts after 100, 200, 300, 400, and 500 h reactions was investigated by EDX and no carbon deposition was observed.

Energy-Absorbing Capacity of Polyurethane/SiC/Glass-Epoxy Laminates Under Impact Loading

This paper presents the energy absorption of target materials with combinations of polyurethane (PU) foam, PU sheet, SiC inserts, and SiC plate bonded to glass fiber reinforced composite laminate backing during impact loading. SiC inserts and SiC plates are bonded as front layer to enhance energy absorption and to protect composite laminate. The composite laminates are prepared by hand lay-up process and other layers are bonded by using epoxy. Low-velocity impact is conducted by using drop mass setup, and mild steel spherical nosed impactor is used for impact testing of target in fixed boundary conditions. Energy absorption and damage are compared to the target plates when subjected to impact at different energy levels. The energy absorbed in various failure modes is analyzed for various layers of target. Failure in the case of SiC inserts is local, and the insert under the impact point is damaged. However, in the other cases, the SiC plate is damaged along with fiber failure and delamination on the composite backing laminate. It is observed that the energy absorbed by SiC plate layered target is higher than SiC inserts layered target.

A novel traveling wave piezoelectric actuated tracked mobile robot utilizing friction effect

A novel traveling wave piezoelectric-actuated tracked mobile robot with potential application to robotic rovers was proposed and investigated in this study. The proposed tracked mobile robot is composed of a parallelogram-frame-structure piezoelectric transducer with four rings and a metal track. Utilizing the converse piezoelectric and friction effects, traveling waves were propagated in the rings and then the metal track was actuated by the piezoelectric transducer. Compared with traditional tracked mechanisms, the proposed tracked mobile robot has a simpler and more compact structure without lubricant, which eliminates the problem of lubricant volatilization and deflation, thus, it could be operated in the vacuum environment. Dynamic characteristics were simulated and measured to reveal the mechanism of actuating track of the piezoelectric transducer. Experimental investigations of the traveling wave piezoelectric-actuated tracked mobile robot were then carried out, and the results indicated that the robot prototype with a pair of exciting voltages of 460 Vpp is able to achieve a maximum velocity of 57 mm s−1 moving on the foam plate and possesses the obstacle crossing capability with a maximum height of 27 mm. The proposed tracked mobile robot exhibits potential to be the driving system of robotic rovers.

초음파와 탄성 구조 모델을 이용한 캘빈 폼 재료의 탄성계수 평가

가벼운 다공성 구조재로서 널리 사용되는 캘빈 폼(foam) 재료의 탄성특성을 초음파를 이용하여 조사하였다. 캘빈 폼의 구조는 tetrakaidecahedron의 단위 셀(unit cell)이 규칙적으로 3차원 배열된 구조를 갖고 있는데 본 연구에서는 SoildWorks 프로그램에서 캘빈 단위 셀을 설계하고 ABS 플라스틱 재료를 이용하여 3차원 프린터로 제작한 후 초음파시험을 수행하였다. 캘빈 구조체는 기공이 많은 재료이기 때문에 초음파가 투과할 수 없어서 빈 공간을 모두 파라핀 왁스로 충진하여 초음파가 투과할 수 있도록 하였다. 파라핀을 충진한 캘빈 구조체는 초음파의 비행시간(TOF)을 이용하여 초음파 속도를 계산한 후, 이 복합 구조체에 대한 탄성 구조 모델을 기반으로 캘빈 구조체만의 탄성계수를 계산하였다. 측정된 캘빈 구조체의 탄성계수 값은 모재(ABS 플라스틱) 탄성계수의 약 3.4%가 되는 것으로 나타났는데 이 평가 결과는 선행된 연구 결과들에서 나타난 실험값이나 이론 해석 결과와 잘 일치하는 것을 확인할 수 있었다. A Kelvin foam plate - widely used in the energy and transport industries as a lightweight structural material - was examined to estimate its Young's modulus using ultrasound. An isotropic tetrakaidecahedron foam structure was designed in SolidWorks and printed using 3D printer with an ABS plastic material. The 3D printed foam structure was used to build a foam plate with a 14 mm thickness (<TEX>$50mm{\times}100mm$</TEX> in size) for the ultrasonic test. The Kelvin foam plate, a significantly porous medium, was completely filled with paraffin wax to enable the ultrasound to penetrate through the porous medium. The acoustic wave velocity of the wax-filled Kelvin foam was measured using the time of flight (TOF) method. Furthermore, the elastic modulus of the Kelvin foam was estimated based on an elastic structural model developed in this study. The Young's modulus of the produced Kelvin foam was observed to be approximately 3.4% of the bulk value of the constituent material (ABS plastic). This finding is consistent with experimental and theoretical results reported by previous studies.

Effects of Perforation on Rigid PU Foam Plates: Acoustic and Mechanical Properties.

Factories today are equipped with diverse mechanical equipment in response to rapid technological and industrial developments. Industrial areas located near residential neighborhoods cause massive environmental problems. In particular, noise pollution results in physical and psychological discomfort, and is a seen as invisible and inevitable problem. Thus, noise reduction is a critical and urgent matter. In this study, rigid polyurethane (PU) foam plates undergo perforation using a tapping machine. The mechanical and acoustic properties of these perforated plates as related to perforation rate and perforation depth are evaluated in terms of compression strength, drop-weight impact strength, and sound absorption coefficient. Experimental results indicate that applying the perforation process endows the rigid PU foaming plates with greater load absorption and better sound absorption at medium and high frequencies.

Experimental Evaluation of Fluid Dynamic and Thermal Behaviors in Compact Heat Exchanger with Aluminum Foam

Abstract In this paper an experimental investigation on forced convection in a compact heat exchanger made up with an aluminum foam plate of 212.5 mm x 212.5 mm with a thickness of 40 mm and a single array with five circular tubes is presented. The foam has a porosity of 0.93 with 10, 20 and 30 pores per inch and the tubes in aluminum have internal and external diameters equal to 9.5 mm and 12.5 mm. The test rig consists of an open air channel and a closed water cycle and the aluminum foam plate is placed inside the channel. The performances of the compact heat exchanger are evaluated for assigned hot water mass flow rate and different hot water inlet temperatures and air mass flow rate. Results are given in terms of heat transfer rates and pressure drops as a function of air velocity and Reynolds numbers. The evaluation of dimensionless, Colburn factor and Nusselt number is performed for different air mass flow rates and hot water inlet temperatures.

Formation mechanism and three-point bending behaviour of directly fabricated aluminium foam plates

New-style smooth-faced aluminium foam plates (AFPs) covered by dense skins have been fabricated directly. AFPs with porosity ranging from 79.3 to 85.2% and with an average diameter of 2.3 to 2.7 mm are obtained via the melt foaming method. The formation mechanism of external dense skins is studied. The dense skin is composed of a cell wall of non-ruptured bubbles, a coarse region formed from ruptured bubbles and plateau borders. The fracture mechanism of AFPs is studied based on static three-point bending tests. They show that the cracked region is only observed at the centre of the experimental samples and that brittle fracture is the main fracture mechanism of these AFPs.

Functionally Graded Aluminum Foam Fabricated by Friction Powder Sintering Process with Traversing Tool

Functionally graded aluminum foam (FG Al foam) is a new class of Al foam in which the pore structure varies over the foam, resulting in corresponding variations in the mechanical properties of the foam. In this study, FG Al foam plates were fabricated by a friction powder sintering (FPS) process with a traversing tool that is based on a previously developed sintering and dissolution process. The variation of the mechanical properties was realized by setting the volume fraction φ of NaCl in the mixture to 60, 70, and 80%. Long FG Al foam plates were fabricated with a length equal to the tool traversing length with φ varying in the tool traversing direction. From x-ray computed tomography observation, it was shown that the density of the Al foam decreased with increasing φ. In contrast, almost uniform pore structures were obtained in each area. According to the results of compression tests on each area, the plateau stress and energy absorption tended to decrease with increasing φ. Therefore, it was shown that FG Al foam plates with varying mechanical properties can be fabricated by the FPS process with the traversing tool.

TU‐AB‐BRA‐05: Optimization of a Novel Large Field of View Distortion Phantom for MR‐Only Treatment Planning

Purpose:MR‐only treatment planning requires images of high geometric fidelity, particularly for large fields of view (FOV). However, the availability of large FOV distortion phantoms with accompanying analysis software is currently limited to in‐house solutions. This work sought to optimize the design of a modular distortion phantom that can accommodate several bore configurations and implement distortion corrections.Methods:1.0T MR and CT images were acquired of twelve urethane foam samples of various densities and strengths. Samples were precision machined to accommodate 6 mm diameter paintballs used as landmarks and signal‐to‐noise ratio was calculated. Final material candidates were selected by balancing strength, machinability, weight, and cost. Bore sizes and minimum aperture width resulting from couch position were tabulated from the literature for 13 systems across 4 vendors. Bore geometry and couch position were simulated in MATLAB to generate machine‐specific models to optimize the phantom build. Previously developed software for distortion characterization (control point detection, polynomial fitting, and correction map generation) was modified for several magnet geometries and integrated into Slicer, a widely available image analysis toolkit.Results:All foam samples provided sufficient image contrast with paintball landmarks. Urethane foam with a compressive strength of ∼1000psi and density of 20lb/ft3 was chosen for its accurate machinability and relatively light weight. A modular phantom design was optimized to accommodate all magnet geometries with the following parameters: 15 foam plates, 55×55×37.5cm, 5,082 landmarks, and 66 lbs. To accommodate wide bore magnets (&gt;70 cm), an extended build spanned 55×55×50cm over 20 plates with 7,497 landmarks and weighing 97lbs. Distortion characterization software was implemented as an external module into Slicer's plugin framework.Conclusion:We optimized the design and implementation of a modular, extendable distortion phantom to support an MR‐only workflow and MR‐IGRT. The phantom will be useful for future multi‐institution collaborations and cross‐validation studies.The submitting institution has research agreements with Philips Healthcare. Research sponsored by a Henry Ford Health System Internal Mentored Grant. Technical support and initial distortion phantom design was provided by GE Healthcare.

Hybrid auxetic foam and perforated plate composites for human body support

The article describes the design, manufacturing, modelling and testing of a hybrid composite support made from auxetic open cell foam liners and curved thermoplastic plates with rhomboidal perforations for human body support. Both the foam and the curved perforated plate have in‐plane negative Poisson's ratio behaviour. The static bending stiffness of the hybrid auxetic composite support is modelled using an analytical and Finite Element approach benchmarked against experimental results from three‐point bending tests. The benchmarked Finite Element models are used to develop a map of optimised static stiffness versus the geometry of the rhomboidal perforations. A Design of Experiment testing campaign is also carried out on 16 hybrid auxetic composite plates to understand the interaction and correlation of the static bending versus the geometry of the perforations and the contribution given by the auxetic foam liner.

Ultrasonic Estimation and FE Analysis of Elastic Modulus of Kelvin Foam

The elastic modulus of a 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam with 3 mm unit cell is designed and printed layer upon layer to fabricate a Kelvin foam plate of 14 mm thickness with a 3D CAD/printer using ABS plastic. The Kelvin foam plate is completely filled with paraffin wax for impedance matching, so that the acoustic wave may propagate through the porous foam plate. The acoustic wave velocity of the foam plate is measured using the time-of-flight (TOF) method and is used to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity. Finite element method (FEM) and micromechanics is applied to the Kelvin foam plate to calculate the theoretical elastic modulus using a non-isotropic tetrakaidecahedron model. The predicted elastic modulus of the Kelvin foam plate from FEM and micromechanics model is similar, which is only 3-4% of the bulk material. The experimental value of the elastic modulus from the ultrasonic method is approximately twice as that of the numerical and theoretical methods because of the flexural deformation of the cell edges neglected in the ultrasonic method.

Ultrasonic Measurement of Elastic Modulus of Kelvin Foam

Elastic modulus of 3D-printed Kelvin foam plate is investigated by measuring the acoustic wave velocity of 1 MHz ultrasound. An isotropic tetrakaidecahedron foam of 3 mm unit cell is designed and printed layer upon layer to fablicate a Kelvin foam plate of 14mm thickness by 3D CAD/printer using ABS plastic. The Kelvin foam plate is filled completely with paraffin wax for impedance matching, so that acoustic wave may propagate through the porous foam plate. The acoustic wave velocity of the foam plate is measured using the time-of-flight (TOF) method to calculate the elastic modulus of the Kelvin foam plate based on acousto-elasticity.

Electrochemical hydrogen storage in EPD made porous Ni-CNT electrode

The hydrogen storage capacity of multi-wall carbon nanotubes (MWCNTs), purified and doped with nano-Nickel particles, is investigated using chronopotentiometry. Several factors such as current magnitude, effect of the number of charge and discharge cycles as well as annealing effect are studied. The X-ray Diffraction (XRD) results indicate that pickling method removes most of the catalysts. Carbon nanotubes (CNTs) are put on nickel foam of nano scale porosities by Electrophoretic deposition (EPD) method. Scanning Electron Microscopy (SEM) technique shows the surface of nickel foam plate. Deposition of nickel particles on CNTs is conducted by electroplating. In order to measure the hydrogen storage capacity, electrodes of CNT and Ni-CNT are used as working electrodes in the three-electrode system. Different results of charge and discharge for various currents in different electrodes show that Ni-CNTs have a maximum discharge capacity (3520 mAh/gr) compared to other electrodes in the optimum current of 2 mA. By increasing the number of cycles in constant current, the capacity is increased to reach a constant amount. Annealing operation leads to more strength of CNTs on the surface.

Fabrication, Microstructure and Shear Properties of Al Foam Sandwich

Aluminum foam sandwich (AFS) structure materials have drawn much attention due to their unique structural and functional properties. However, the use of AFS materials as an attractive candidate for some applications was limited. In this work, AFS was fabricated by the brazing method, using Al-Si-based alloy, aluminum foam and steel plates as filler, matrix and panels, respectively. The microstructures of the soldered interfacial region, elemental distributions and phase identification were determined by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The diffusion behavior of Si, Al, Fe and Cr was investigated. The effect of brazing time on the shear strengths of soldered joints was also analyzed. The results showed that the microstructures of joints were changed on increasing the brazing time. When the brazing time was 5 min, the solder started melting, which led to low shear strength. When increasing the brazing time to 10 min, the shear strength reached the peak value of 6.26 MPa due to the formation of a layer plate structure in the joints. When further increasing the brazing time, a number of Al/Fe intermetallic compound were formed in the joints, leading to a decrease of the shear strength due to the formation of brittle phase.

Behavior of Reinforced Concrete Slab with Aluminum Foam Panels Subjected to Blast Loadings

The main objective of the current research work is to investigate the dynamic response of reinforced concrete (RC) slab protected by a composed layer of aluminum foam panel and steel plate. The RC slab and the protection layer were subjected to blast loading. A parametric study was conducted in which a series of numerical simulations of protected and unprotected RC slabs was performed using hydro-code software (i.e. AUTODYN 3D). A set of published experimental tests was used to validate the numerical models proposed. The models were simulated as protected and unprotected RC slabs subjected to different blast loads. In the numerical simulations, the dynamic behavior of reinforced concrete and aluminum foam materials as porous materials were defined utilizing different Equations of State (EOS) and strength models. Time-dependent results of the response of the RC slabs subjected to the blast loads were obtained. The computed results were then utilized to study the efficiency of aluminum foam and steel plate layer to maintain the maximum deflection of the RC slab within its elastic limit.

Al-Si Alloy Foam Prepared by Two Step Foaming Method

Two basic methods can be used to fabricate aluminum foam. One is powder metallurgy route which can provide the near net shape casting containing aluminum foam core, and the other is melt foaming route which can prepare large scale aluminum foam plate directly. To combine the advantages of above two methods, the precursor was obtained through melt foaming route and then baked in a furnace like that of powder metallurgy method in this investigation. The test results indicated that the SiC and TiH2 particles after treatment in air could be dispersed in Al-Si matrix alloy melt and the precursors were obtained. The porosity and their pore diameter of the precursors decreased along with the temperature reducing as well as the magnesium or SiC particles adding. The density of Al-Si alloy foam decreased with the elevation of baking temperature and extension of heating time before collapse of foam block occurred. The foaming process parameters were seriously affected by the aluminum alloy composition.

Thermal Enhancement Cartridge Heater Modified (Tech Mod) Tritium Hydride Bed Development Part I – Design and Fabrication

The Savannah River Site (SRS) tritium facilities have used 1st generation (Gen1) LaNi4.25Al0.75 (LANA0.75) metal hydride storage beds for tritium absorption, storage, and desorption. The Gen1 design utilizes hot and cold nitrogen supplies to thermally cycle these beds. Second and 3rd generation (Gen2 and Gen3) storage bed designs include heat conducting foam and divider plates to spatially fix the hydride within the bed. For thermal cycling, the Gen2 and Gen 3 beds utilize internal electric heaters and glovebox atmosphere flow over the bed inside the bed external jacket for cooling.The currently installed Gen1 beds require replacement due to tritium aging effects on the LANA0.75 material, and cannot be replaced with Gen2 or Gen3 beds due to different designs of these beds. At the end of service life, Gen1 bed desorption efficiencies are limited by the upper temperature of hot nitrogen supply. To increase end-of-life desorption efficiency, the Gen1 bed design was modified, and a Thermal Enhancement Cartridge Heater Modified (TECH Mod) bed was developed. Internal electric cartridge heaters in the new design to improve end-of-life desorption, and also permit in-bed tritium accountability (IBA) calibration measurements to be made without the use of process tritium. Additional enhancements implemented into the TECH Mod design are also discussed.

데크플레이트와 경량성형재가 결합된 슬래브의 차음성능에 대한 실물실험 평가

This study is to explore floor impact sound and sound insulation of reinforced concrete structure with void-deck slab system which combines polystyrene void foam and T-shaped steel deck plate. A void-deck slab system can effectively reduce the amount of concrete used and hence the mass of a reinforced concrete slab. Also void slab system has dynamically favorable for bending. Three-bay 2-story building was constructed as a mock up test specimen using void-deck slab system and floor impact sound was measured to valuate sound insulation performance. Light weight floor impact and heavy weight floor impact were investigated. Light weight floor impact pressure levels were 32dB, 28dB, and 29db at representative locations which are 1 st level in the floor impact sound insulation performance grading system. The heavy-weight floor impact pressure levels were 44dB, 45dB, and 43dB at representative locations which are 2 nd level in the floor impact sound insulation performance grading system. Therefore void-deck slab system can be used in public housing apartment building in terms of not only effectively reduced construction materials but also floor impact sound insulation.