Showing papers by "Wright-Patterson Air Force Base published in 2013"
TL;DR: High-performance multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and thermal conductivity of carbon fibers with the specific electrical Conductivity of metals are reported.
Abstract: Broader applications of carbon nanotubes to real-world problems have largely gone unfulfilled because of difficult material synthesis and laborious processing. We report high-performance multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and thermal conductivity of carbon fibers with the specific electrical conductivity of metals. These fibers consist of bulk-grown CNTs and are produced by high-throughput wet spinning, the same process used to produce high-performance industrial fibers. These scalable CNT fibers are positioned for high-value applications, such as aerospace electronics and field emission, and can evolve into engineered materials with broad long-term impact, from consumer electronics to long-range power transmission.
1,092 citations
TL;DR: The synthesis of ordered, stacked macroscopic three-dimensional solid scaffolds of graphene oxide fabricated via chemical cross-linking of two-dimensional GO building blocks form highly porous interconnected structures, and the controlled reduction of these structures leads to formation of 3D conductive graphene scaffolds.
Abstract: The creation of three-dimensionally engineered nanoporous architectures via covalently interconnected nanoscale building blocks remains one of the fundamental challenges in nanotechnology. Here we report the synthesis of ordered, stacked macroscopic three-dimensional (3D) solid scaffolds of graphene oxide (GO) fabricated via chemical cross-linking of two-dimensional GO building blocks. The resulting 3D GO network solids form highly porous interconnected structures, and the controlled reduction of these structures leads to formation of 3D conductive graphene scaffolds. These 3D architectures show promise for potential applications such as gas storage; CO2 gas adsorption measurements carried out under ambient conditions show high sorption capacity, demonstrating the possibility of creating new functional carbon solids starting with two-dimensional carbon layers.
227 citations
TL;DR: The results suggest that the relationship between functional networks and behavior can be better understood by using shorter time windows and also by considering both intraindividual and interindividual variability.
Abstract: A better understanding of how behavioral performance emerges from interacting brain systems may come from analysis of functional networks using functional magnetic resonance imaging. Recent studies comparing such networks with human behavior have begun to identify these relationships, but few have used a time scale small enough to relate their findings to variation within a single individual's behavior. In the present experiment we examined the relationship between a psychomotor vigilance task and the interacting default mode and task positive networks. Two time-localized comparative metrics were calculated: difference between the two networks' signals at various time points around each instance of the stimulus (peristimulus times) and correlation within a 12.3-s window centered at each peristimulus time. Correlation between networks was also calculated within entire resting-state functional imaging runs from the same individuals. These metrics were compared with response speed on both an intraindividual and an interindividual basis. In most cases, a greater difference or more anticorrelation between networks was significantly related to faster performance. While interindividual analysis showed this result generally, using intraindividual analysis it was isolated to peristimulus times 4 to 8 s before the detected target. Within that peristimulus time span, the effect was stronger for individuals who tended to have faster response times. These results suggest that the relationship between functional networks and behavior can be better understood by using shorter time windows and also by considering both intraindividual and interindividual variability. Hum Brain Mapp 34:3280–3298, 2013. © 2012 Wiley Periodicals, Inc.
206 citations
TL;DR: A voltage-impulse-induced two-step ferroelastic switching pathway can be used to in situ manipulate the magnetic anisotropy and enable non-volatile FMR tuning in FeCoB/PMN-PT (011) multiferroic heterostructures.
Abstract: A critical challenge in realizing magnetoelectrics based on reconfigurable microwave devices, which is the ability to switch between distinct ferromagnetic resonances (FMR) in a stable, reversible and energy efficient manner, has been addressed. In particular, a voltage-impulse-induced two-step ferroelastic switching pathway can be used to in situ manipulate the magnetic anisotropy and enable non-volatile FMR tuning in FeCoB/PMN-PT (011) multiferroic heterostructures.
197 citations
TL;DR: Dual E- and H-field control of microwave performance with enhanced ferromagnetic resonance (FMR) tunability has been demonstrated in microwave composites FeGaB/PZN-PT(011) and provides a framework for developing lightweight, energy efficient, voltage-tunable RF/microwave devices.
Abstract: Dual E- and H-field control of microwave performance with enhanced ferromagnetic resonance (FMR) tunability has been demonstrated in microwave composites FeGaB/PZN-PT(011) A voltage-impulse-induced non-volatile magnetization switching was also realized in this work, resulting from the hysteretic type of phase transition in PZN-PT(011) at high electric fields The results provide a framework for developing lightweight, energy efficient, voltage-tunable RF/microwave devices
177 citations
TL;DR: In this article, the combination of inorganic-nanoparticles and organic-polymers has led to a wide variety of advanced materials, including polymer nanocomposites (PNCs).
Abstract: Over the past three decades, the combination of inorganic-nanoparticles and organic-polymers has led to a wide variety of advanced materials, including polymer nanocomposites (PNCs). Recently, synthetic innovations for attaching polymers to nanoparticles to create “hairy nanoparticles” (HNPs) has expanded opportunities in this field. In addition to nanoparticle compatibilization for traditional particle–matrix blending, neat-HNPs afford one-component hybrids, both in composition and properties, which avoids issues of mixing that plague traditional PNCs. Continuous improvements in purity, scalability, and theoretical foundations of structure–performance relationships are critical to achieving design control of neat-HNPs necessary for future applications, ranging from optical, energy, and sensor devices to lubricants, green-bodies, and structures.
170 citations
TL;DR: The contribution of various mechanisms to the strength of commercial-purity titanium following rolling at 77 and 293 K was analyzed quantitatively in this article, which resulted in the formation of a microstructure with a grain/subgrain size of ∼80nm at 77 K or ∼200 K at 293 K. At 77 K, twinning was more extensive in terms of the fraction of twinned grains and the duration of the twinning stage.
160 citations
TL;DR: This discussion focuses primarily on polymer-based photonic gels that are directly or indirectly fabricated via self-assembly, as these materials are promising soft material platforms for scalable mechanochromic sensors.
Abstract: Polymer gels are remarkable materials with physical structures that can adapt significantly and quite rapidly with changes in the local environment, such as temperature, light intensity, electrochemistry, and mechanical force An interesting phenomenon observed in certain polymer gel systems is mechanochromism - a change in color due to a mechanical deformation Mechanochromic photonic gels are periodically structured gels engineered with a photonic stopband that can be tuned by mechanical forces to reflect specific colors These materials have potential as mechanochromic sensors because both the mechanical and optical properties are highly tailorable via incorporation of diluents, solvents, nanoparticles, or polymers, or the application of stimuli such as temperature, pH, or electric or strain fields Recent advances in photonic gels that display strain-dependent optical properties are discussed In particular, this discussion focuses primarily on polymer-based photonic gels that are directly or indirectly fabricated via self-assembly, as these materials are promising soft material platforms for scalable mechanochromic sensors
147 citations
TL;DR: A theoretical framework in which the effects of sleep loss on cognition may be understood from the deficits in the underlying neurobiology to the applied consequences in real-world job tasks is outlined.
136 citations
TL;DR: In this article, near-perfect IR light absorption at multiple wavelengths has been experimentally demonstrated by using multiplexed metal square plasmonic resonance structures, where the peak absorption wavelengths are primarily determined by the sizes of the metal squares in the multiplexing structures.
Abstract: Near-perfect IR light absorption at multiple wavelengths has been experimentally demonstrated by using multiplexed metal square plasmonic resonance structures. Optical power absorption over 95% has been observed in dual-band metamaterial absorbers at two separate wavelengths, and optical power absorption over 92.5% has been observed in triple-band metamaterial absorbers at three separate wavelengths. The peak absorption wavelengths are primarily determined by the sizes of the metal squares in the multiplexed structures. Electrical field distributions in the middle of the dielectric spacer layer were calculated at the peak absorption wavelengths. It is found that the strong light absorption corresponds to local quadrupole plasmon resonance modes in the metamaterial structures.
130 citations
TL;DR: In this paper, a cycle analysis model for an airbreathing, rotating detonation wave engine (RDE) is presented, which consists of a steady inlet system with an isolator which delivers air into an annular combustor.
TL;DR: This review focuses on the mechanisms of thin-film growth using low-pressure PECVD and current applications of classic PECV thin films of organic and inorganic materials in biological environments and the novel application of low- pressure PECVA in the deposition of biological materials.
Abstract: Chemical vapor deposition (CVD) has been used historically for the fabrication of thin films composed of inorganic materials. But the advent of specialized techniques such as plasma-enhanced chemical vapor deposition (PECVD) has extended this deposition technique to various monomers. More specifically, the deposition of polymers of responsive materials, biocompatible polymers, and biomaterials has made PECVD attractive for the integration of biotic and abiotic systems. This review focuses on the mechanisms of thin-film growth using low-pressure PECVD and current applications of classic PECVD thin films of organic and inorganic materials in biological environments. The last part of the review explores the novel application of low-pressure PECVD in the deposition of biological materials.
TL;DR: The current study provides a reproducible model of mild TBI in mice that exhibits pathologic features of mildTBI in humans and suggests that serum cytokines, such as IL-6, may be effective biomarkers for severity of head injury.
TL;DR: A biological pattern of surface functionality that is a gradient of surface polarity of the ridge structures that runs from their polar tops to their less-polar bottoms is described, showing a biological pattern design that could stimulate numerous technological applications ranging from photonic security tags to self-cleaning surfaces, gas separators, protective clothing, sensors, and many others.
Abstract: For almost a century, the iridescence of tropical Morpho butterfly scales has been known to originate from 3D vertical ridge structures of stacked periodic layers of cuticle separated by air gaps. Here we describe a biological pattern of surface functionality that we have found in these photonic structures. This pattern is a gradient of surface polarity of the ridge structures that runs from their polar tops to their less-polar bottoms. This finding shows a biological pattern design that could stimulate numerous technological applications ranging from photonic security tags to self-cleaning surfaces, gas separators, protective clothing, sensors, and many others. As an important first step, this biomaterial property and our knowledge of its basis has allowed us to unveil a general mechanism of selective vapor response observed in the photonic Morpho nanostructures. This mechanism of selective vapor response brings a multivariable perspective for sensing, where selectivity is achieved within a single chemically graded nanostructured sensing unit, rather than from an array of separate sensors.
TL;DR: A novel metamaterial synthesized by bottom-up self-assembly of gold nanorods is reported, enabling the first demonstration of plasmon-induced transparency at visible wavelengths.
Abstract: The phenomenon of plasmon-induced transparency holds immense potential for high sensitivity sensors and optical information processing due to the extreme dispersion and slowing of light within a narrow spectral window. Unfortunately plasmonic metamaterials demonstrating this effect has been restricted to infrared and greater wavelengths due to requisite precision in structure fabrication. Here we report a novel metamaterial synthesized by bottom-up self-assembly of gold nanorods. The small dimensions (≤ 50/20 nm, length/diameter), atomically smooth surfaces, and nanometer resolution enable the first demonstration of plasmon-induced transparency at visible wavelengths. The slow-down factors within the reduced symmetry heterodimer cluster are comparable to longer wavelength counterparts. The inherent spectral tunability and facile large-scale integration afforded by self-assembled metamaterials will open a new paradigm for physically realizable on-chip photonic device designs.
TL;DR: This paper explored individual differences in ability and motivation factors of retention in first-year college students using discrete-time survival mixture analysis to model university retention and found gender, ACT scores, and conscientiousness are significant predictors of retention, but parents' education level was not a significant predictor.
Abstract: The current study explored individual differences in ability and motivation factors of retention in first-year college students. We used discrete-time survival mixture analysis to model university retention. Parents' education, gender, American College Test (ACT) scores, conscientiousness, and trait affectivity were explored as predictors of retention. Results indicate gender, ACT scores, and conscientiousness are significant predictors of retention, but parents' education level was not a significant predictor. Positive affectivity and negative affectivity also were significant predictors of university retention when added to the model. Interestingly, once affectivity was added to the model, conscientiousness was no longer a significant predictor, indicating conscientiousness may be an amalgamation of motivation and ability. Implications for research and theory are discussed.
TL;DR: It is demonstrated action videogames can increase people's ability to take on additional tasks by increasing attentional capacity, without interfering with the primary tasks.
TL;DR: In this article, the authors investigate photo-initiated snap-through in bistable arches formed from samples composed of azobenzene-functionalized polymers (both amorphous polyimides and liquid crystal polymer networks) and report orders-of-magnitude enhancement in actuation rates and powers.
Abstract: Photomechanical effects in polymeric materials and composites transduce light into mechanical work. The ability to control the intensity, polarization, placement, and duration of light irradiation is a distinctive and potentially useful tool to tailor the location, magnitude, and directionality of photogenerated mechanical work. Unfortunately, the work generated from photoresponsive materials is often slow and yields very small power densities, which diminish their potential use in applications. Here, we investigate photoinitiated snap-through in bistable arches formed from samples composed of azobenzene-functionalized polymers (both amorphous polyimides and liquid crystal polymer networks) and report orders-of-magnitude enhancement in actuation rates (approaching 102 mm/s) and powers (as much as 1 kW/m3). The contactless, ultra-fast actuation is observed at irradiation intensities <<100 mW/cm2. Due to the bistability and symmetry of the snap-through, reversible and bidirectional actuation is demonstrated. A model is developed to elucidate the underlying mechanics of the snap-through, specifically focusing on isolating the role of sample geometry, mechanical properties of the materials, and photomechanical strain. Using light to trigger contactless, ultrafast actuation in an otherwise passive structure is a potentially versatile tool to use in mechanical design at the micro-, meso-, and millimeter scales as actuators, as well as switches that can be triggered from large standoff distances, impulse generators for microvehicles, microfluidic valves and mixers in laboratory-on-chip devices, and adaptive optical elements.
TL;DR: The frontiers of knowledge for both biological adaptive coloration, with a focus on cephalopods, and synthetic reflective e-paper are merged within a consistent framework of scientific metrics to gain new insights from millions of years of natural selection and evolution.
Abstract: Adaptive reflective surfaces have been a challenge for both electronic paper (e-paper) and biological organisms. Multiple colours, contrast, polarization, reflectance, diffusivity and texture must all be controlled simultaneously without optical losses in order to fully replicate the appearance of natural surfaces and vividly communicate information. This review merges the frontiers of knowledge for both biological adaptive coloration, with a focus on cephalopods, and synthetic reflective e-paper within a consistent framework of scientific metrics. Currently, the highest performance approach for both nature and technology uses colourant transposition. Three outcomes are envisioned from this review: reflective display engineers may gain new insights from millions of years of natural selection and evolution; biologists will benefit from understanding the types of mechanisms, characterization and metrics used in synthetic reflective e-paper; all scientists will gain a clearer picture of the long-term prospects for capabilities such as adaptive concealment and signalling.
TL;DR: Evidence is presented to demonstrate that materials-directing peptides can be controllably modified to substantially enhance particle functionality without significantly altering nanostructural morphology.
Abstract: Peptide-based methods represent new approaches to selectively produce nanostructures with potentially important functionality. Unfortunately, biocombinatorial methods can only select peptides with target affinity and not for the properties of the final material. In this work, we present evidence to demonstrate that materials-directing peptides can be controllably modified to substantially enhance particle functionality without significantly altering nanostructural morphology. To this end, modification of selected residues to vary the site-specific binding strength and biological recognition can be employed to increase the catalytic efficiency of peptide-capped Pd nanoparticles. These results represent a step toward the de novo design of materials-directing peptides that control nanoparticle structure/function relationships.
TL;DR: Modeling of the ultrastructural data and spectral measurements with Lorenz‐Mie theory and Monte Carlo simulations suggest that leucophore whiteness is produced by incoherent scattering based upon a randomly ordered system, which may provide a template for bio‐inspired approaches to efficient light scattering in materials science and optical engineering.
Abstract: Throughout nature, elegant biophotonic structures have evolved into sophisticated arrangements of pigments and structural reflectors that manipulate light in the skin, cuticles, feathers and fur of animals. Not many spherical biophotonic structures are known and those described are often angle dependent or spectrally tuned. White light scattering by the flexible skin of cuttlefish (Sepia officinalis) is examined and how the unique structure and composition of leucophore cells serve as physiologically passive reflectors approximating the optical properties of a broadband Lambertian surface is investigated. Leucophores are cells that contain thousands of spherical microparticles called leucosomes that consist of sulfated glycoproteins or proteoglycans and reflectin. A leucophore containing ≈12 000 leucosome microspheres is characterized three-dimensionally by electron microscopy and the average refractive index of individual leucosomes is measured by holographic microscopy to be 1.51 ± 0.02. Modeling of the ultrastructural data and spectral measurements with Lorenz-Mie theory and Monte Carlo simulations suggest that leucophore whiteness is produced by incoherent scattering based upon a randomly ordered system. These soft, compliant, glycosylated proteinacious spheres may provide a template for bio-inspired approaches to efficient light scattering in materials science and optical engineering.
TL;DR: In this article, the formation of ideally packed clusters at the expense of atomic arrangements with excess or deficient free volume can explain glass forming by a similar mechanism, which is reflected in the structural relaxation of a metallic glass during constant pressure cooling and the time evolution of structure at a constant volume.
Abstract: The atomic structure of the supercooled liquid has often been discussed as a key source of glass formation in metals. The presence of icosahedrally coordinated clusters and their tendency to form networks have been identified as one possible structural trait leading to glass-forming ability in the Cu-Zr binary system. In this paper, we show that this theory is insufficient to explain glass formation at all compositions in that binary system. Instead, we propose that the formation of ideally packed clusters at the expense of atomic arrangements with excess or deficient free volume can explain glass forming by a similar mechanism. We show that this behavior is reflected in the structural relaxation of a metallic glass during constant pressure cooling and the time evolution of structure at a constant volume. We then demonstrate that this theory is sufficient to explain slowed diffusivity in compositions across the range of Cu-Zr metallic glasses.
TL;DR: The work described here highlights a novel approach for the uniform deposition of Sn nanoparticles, which can be used to design electrodes with high capacities and high-rate capabilities.
Abstract: By initially depositing a sub-10 nm-thick SnO2 film, the microstructural evolution that is often considered problematic can be utilized to form Sn nanoparticles on the surface of a 3D current collector for enhanced cycling stability. The work described here highlights a novel approach for the uniform deposition of Sn nanoparticles, which can be used to design electrodes with high capacities and high-rate capabilities.
TL;DR: In this article, the effects of oxygen adsorption and diffusion on the stability, morphology, and charge transfer in single-layer graphene with structural point defects were investigated by density functional theory.
Abstract: In this work, effects of oxygen adsorption and diffusion on the stability, morphology, and charge transfer in single-layer graphene with structural point defects were investigated by density functional theory, specifically for the experimentally characterized monovacancy, double-vacancy, 555–777, 5555–6–7777, and Stone-Wales defects. The theoretical analysis demonstrated strengthened oxygen adsorption on defective graphene as compared to pristine graphene, resulting in trapping of the oxygen onto defects. This was accompanied by significant charge transfer of up to 3e, unlike for pristine graphene. At the same time, atomic oxygen diffuses at different rates dependent on the local environment, however with relatively low barriers (mostly <1 eV), lower than for pristine graphene, thus, revealing an interplay between diffusion and adsorption in this case. Addition of a nonempirical correction to the exchange-correlation functional to take into account London dispersion demonstrated that the vdW-DF PBE functi...
01 Jan 2013
TL;DR: The electromagnetic full-wave simulations for scattering of waves by soil surfaces, bistatic scattering, backscattering, and emissivity which are signatures measured in microwave remote sensing are reviewed.
Abstract: Active and passive microwave remote sensing has been used for monitoring the soil moisture and snow water equivalent. In the interactions of microwaves with bare soil, the effects are determined by scattering of electromagnetic waves by random rough surfaces. In the interactions of microwaves with terrestrial snow, the effects are determined by volume scattering of dense media characterized by densely packed particles. In this paper, we review the electromagnetic full-wave simulations that we have conducted for such problems. In volume scattering problems, one needs many densely packed scatterers in a random medium sample to simulate the physical solutions. In random rough surface scattering problems, one needs many valleys and peaks in the sample surface. In random media and rough surface problems, the geometric characterizations of the media and computer generations of statistical samples of the media are also challenges besides electromagnetic computations. In the scattering of waves by soil surfaces, we consider the soil to be a lossy dielectric medium. The random rough surface is characterized by Gaussian random processes with exponential correlation functions. Surfaces of exponential correlation functions have fine-scale structures that cause significant radar backscattering in active microwave remote sensing. Fine-scale features also cause increase in emission in passive microwave remote sensing. We apply Monte Carlo simulations of solving full 3-D Maxwell's equations for such a problem. A hybrid UV/PBTG/SMCG method is developed to accelerate method of moment solutions. The results are illustrated for coherent waves and incoherent waves. We also illustrate bistatic scattering, backscattering, and emissivity which are signatures measured in microwave remote sensing. For the case of scattering by terrestrial snow, snow is a dense medium with densely packed ice grains. We have used two models: densely packed particles and bicontinuous media. For the case of densely packed particles, we used the Metropolis shuffling method to simulate the positions of particles. The particles are also allowed to have adhesive properties. The Foldy-Lax equations of multiple scattering are used to study scattering from the densely packed spherical particles. The results are illustrated for the coherent waves and incoherent waves. For the case of bicontinuous media, the method developed by Cahn is applied to construct the interfaces from a large number of stochastic sinusoidal waves with random phases and directions. The volume scattering problem is then solved by using CGS-FFT. We illustrate the results of frequency and polarization dependence of such dense media scattering.
TL;DR: In this article, the Navier-Stokes equations were solved using a high-fidelity time-implicit numerical scheme and an implicit large-eddy simulation approach to investigate plasma-based flow control for supersonic flow over a compression ramp.
Abstract: The Navier–Stokes equations were solved using a high-fidelity time-implicit numerical scheme and an implicit large-eddy simulation approach to investigate plasma-based flow control for supersonic flow over a compression ramp. The configuration included a flat-plate region to develop an equilibrium turbulent boundary layer at Mach 2.25, which was validated against a set of experimental measurements. The fully turbulent boundary-layer flow traveled over a 24 deg ramp and produced an unsteady shock-induced separation. A control strategy to suppress the separation through a magnetically-driven surface-discharge actuator was explored. The size, strength, and placement of the model actuator were based on recent experiments at the Princeton University Applied Physics Group. Three control scenarios were examined: steady control, pulsing with a 50% duty cycle, and a case with significant Joule heating. The control mechanism was very effective at reducing the time-mean separation length for all three cases. The ste...
TL;DR: A passive, simple, ultra-low-cost, and easily controlled pumping method based on capillary action of paper that pumps fluid through conventional polymer-based microfluidic channels with steady flow rate and transport of the most common biofluids is presented.
Abstract: In microfluidic systems, a pump for fluid-driving is often necessary. To keep the size of microfluidic systems small, a pump that is small in size, light-weight and needs no external power source is advantageous. In this work, we present a passive, simple, ultra-low-cost, and easily controlled pumping method based on capillary action of paper that pumps fluid through conventional polymer-based microfluidic channels with steady flow rate. By using inexpensive cutting tools, paper can be shaped and placed at the outlet port of a conventional microfluidic channel, providing a wide range of pumping rates. A theoretical model was developed to describe the pumping mechanism and aid in the design of paper pumps. As we show, paper pumps can provide steady flow rates from 0.3 μl/s to 1.7 μl/s and can be cascaded to achieve programmable flow-rate tuning during the pumping process. We also successfully demonstrate transport of the most common biofluids (urine, serum, and blood). With these capabilities, the paper pump has the potential to become a powerful fluid-driving approach that will benefit the fielding of microfluidic systems for point-of-care applications.
TL;DR: In this article, a numerical approach based on 3D nonlinear finite element method has been employed to explore the relation between the processing parameters and the residual stress distribution, which leads to a substantial improvement in bending fatigue life.
Abstract: Laser shock peening (LSP) induced residual stresses significantly affect the high cycle fatigue behavior of certain metals and alloys. Residual stress distribution is a function of various laser parameters (energy, laser pulse width, and spot diameter), the geometry, the material and the laser shot sequencing. Considering the wide range of parameters involved in the LSP process, a numerical approach based on 3D nonlinear finite element method has been employed to explore the relation between the processing parameters and the residual stress distribution. This methodology is applied to a thin coupon of Ti–6Al–2Sn–4Zr–2Mo (Ti-6242) alloy, with a view towards establishing conditions for obtaining through-thickness compressive residual stresses and hence improved bending fatigue life. Material response at very high strain rates in the LSP process is effectively represented using the modified Zerilli–Armstrong material model. The numerical approach is verified by comparison with the experimental results. Effects of laser parameters and laser shot sequencing on final residual stress distribution are studied by performing full scale simulations of LSP patches constituting a large number of laser shots. Based on simulation studies, optimal set of parameters is obtained that produces through thickness compression, which leads to a substantial improvement in bending fatigue life. Fatigue testing results support the recommendations made based on simulation results.
TL;DR: A numerical study of two dimensional DC dielectrophoresis based particle-particle interactions and assembly for multiple particles using a hybrid immersed interface-immersed boundary method to explain the multiple particle interaction and assembly phenomena observed in experiments.
TL;DR: In this paper, the authors measured the crystallographic dependence of the mechanical responses of an α-Ti-7-wt.% Alloy by nanoindentation using spherical and Berkovich indenters, and the dislocation structures resulting from indentation were characterized by electron microscopy.