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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

A novel additive manufacturing compression overmolding process for hybrid metal polymer composite structures

Metal polymer composites combining low density, high strength composites with highly ductile and tough metals have gained traction over the last few decades as lightweight and high-performance materials for industrial applications. However, the mechanical properties are limited by the interfacial bonding strength between metals and polymers achieved through adhesives, welding, and surface treatment processes. In this paper, a novel manufacturing process combining additive manufacturing and compression molding to obtain hybrid metal polymer composites with enhanced mechanical properties is presented. Additive manufacturing enabled deposition of polymeric material with fibers in a predetermined pattern to form tailored charge or preform for compression molding. Here, a grade 300 maraging steel triangular lattice is first fabricated using AddUp FormUp350 laser powder bed system and compression overmolded with additively manufactured long carbon fiber-reinforced polyamide-6,6 (40% wt. CF/PA66) preform. The fabricated hybrid metal polymer composites showed high stiffness and tensile strength. The stiffness and failure characteristics determined from the uniaxial tensile tests were correlated to a finite element model within 20% deviation. Fractographic analyses was performed using microscopy to investigate failure mechanisms of the hybrid structures.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Sulfate performance of blended cements (limestone and illite calcined clay) exposed to aggressive environment after casting

This paper evaluates how early aggressive exposure affects the sulfate resistance of blended cements containing limestone filler and/or calcined clay. Mortar and cement paste specimens were elaborated with different combinations of limestone filler and two different illitic calcined clays and exposed to a sodium sulfate solution shortly after casting. Assessment of sulfate resistance was based on expansion, mass variation, and compressive strength. Microscale evolution and distribution were examined by mercury intrusion porosimetry, X-ray diffraction, and scanning electron microscopy with energy-dispersive spectrometry measurements. Results prove superior sulfate resistance of compositions with high calcined clay content over limestone filler addition. Furthermore, the results reported suggest that the pozzolanic reaction progresses enough to reduce the sulfate ingress even at early exposure conditions. Therefore, calcined clay replacement can still provide effective pore refinement to limit sulfate penetration, increase strength, and reduce available CH to limit expansive phase formation.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Dynamic response of 17-4 stainless steel as a function of manufacturing method and heat treatment

We present a series of plate-impact experiments on 17-4 stainless steel to study the effect of manufacturing method and heat treatment on the Hugoniot elastic limit (HEL), Hugoniot, phase transformation stress, and spallation strength. Two traditional manufacturing methods were considered, wrought processing and casting, as well as two additive manufacturing methods, laser powder-bed fusion (LPBF) and wire-fed electron beam (EBAM). For both LPBF and EBAM 17-4 stainless steel variants, two billets were printed, enabling the application of two unique heat treatments. The HEL stress depended heavily on the thermal history, with the HEL increasing after the formation of Cu-rich precipitates via heat treatment. The Hugoniot response both below and above the phase transition was unaffected by the manufacturing method or heat treatment. The phase transition stress depended heavily on the thermal history, with its variation being attributed to the presence of various microstructural features. This is supported by a marked increase in the phase transition stress after precipitation hardening. These results suggest that the notion of the phase transition stress being dictated by bulk composition is an oversimplification and the stress fields generated by the meso-scale structure are a dominant force. The spallation strength was lower in the cast material compared to all other 17-4 stainless steel variants due to the presence of brittle δ-ferrite inclusions. Additionally, a drop in the tensile strain-rate was observed in the spallation response above the phase transition stress, which was hypothesized to stem from the kinetics of the reversion to the low-pressure phase during spall.

Compressive stress↗
DOE OSTI2020

A reconstructed discontinuous Galerkin method for compressible flows in Lagrangian formulation

In this work, a high-order accurate reconstructed discontinuous Galerkin (rDG) method is developed for solving two-dimensional hydrodynamic problems in cell-centered updated Lagrangian formulation. This method is the Lagrangian limit of the unsplit rDG-ALE formulation, and is obtained by assuming the equality of the grid velocity to the fluid velocity only at cell boundaries. The conservative variables and the Taylor basis defined on the time-dependent moving mesh, provide the piece-wise polynomial expansion in the updated Lagrangian formulation. A multi-directional nodal Riemann solver is implemented for computing the grid velocity at the vertices and the numerical flux at the cell boundaries. A characteristic limiting procedure is extended from the primitive variable version to the conservative variable version, and its performance is compared with the limiter on physical variables. A number of benchmark test cases are conducted to assess the accuracy, robustness, and non-oscillatory property of the DG(P0), DG(P1) and rDG(P1P2) methods. The numerical experiments demonstrate that the developed rDG method is able to attain the designed order of accuracy and the characteristic limiting procedure outperforms the limiter on physical variables in terms of the monotonicity and symmetry preservation for shock problems.

42 ENGINEERING↗
DOE OSTI2022

Enhanced detection of paramagnetic fluorine-19 magnetic resonance imaging agents using zero echo time sequence and compressed sensing

Fluorine-19 ( 19 F) magnetic resonance imaging (MRI) is an emerging technique offering specific detection of labeled cells in vivo. Lengthy acquisition times and modest signal-to-noise ratio (SNR) makes three-dimensional spin-density–weighted 19 F imaging challenging. Recent advances in tracer paramagnetic metallo-perfluorocarbon (MPFC) nanoemulsion probes have shown multifold SNR improvements due to an accelerated 19 F T 1 relaxation rate and a commensurate gain in imaging speed and averages. However, 19 F T 2 -reduction and increased linewidth limit the amount of metal additive in MPFC probes, thus constraining the ultimate SNR. To overcome these barriers, we describe a compressed sampling (CS) scheme, implemented using a “zero” echo time (ZTE) sequence, with data reconstructed via a sparsity-promoting algorithm. Our CS-ZTE scheme acquires k-space data using an undersampled spherical radial pattern and signal averaging. Image reconstruction employs off-the-shelf sparse solvers to solve a joint total variation and -norm regularized least square problem. To evaluate CS-ZTE, we performed simulations and acquired 19 F MRI data at 11.7 T in phantoms and mice receiving MPFC-labeled dendritic cells. For MPFC-labeled cells in vivo, we show SNR gains of ~6.3 × with 8-fold undersampling. We show that this enhancement is due to three mechanisms including undersampling and commensurate increase in signal averaging in a fixed scan time, denoising attributes from the CS algorithm, and paramagnetic reduction of T 1 . Importantly, 19 F image intensity analyses yield accurate estimates of absolute quantification of 19 F spins. Overall, the CS-ZTE method using MPFC probes achieves ultrafast imaging, a substantial boost in detection sensitivity, accurate 19 F spin quantification, and minimal image artifacts.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Modeling Sequences of Earthquakes and Aseismic Slip (SEAS) in Elasto-Plastic Fault Zones With a Hybrid Finite Element Spectral Boundary Integral Scheme

We present a coupled finite element spectral boundary integral framework for modeling sequences of earthquakes and aseismic slip on a 2-D planar rate-and-state fault with off-fault visco-plastic response in the plane strain approximation. The model resolves both slow aseismic deformation and inertia effects during rapid slip. As an application, we perform two sets of simulations with different choices of cohesion to explore the co-evolution of fault slip, bulk plasticity and local stress fields. The first set implements a relatively large value of the cohesion parameter, which results in limiting inelastic strain accumulation to dynamic rupture phases. The second set implements a smaller cohesion, allowing for plastic strain to accumulate in both seismic and aseismic phases. For the first model, our results indicate that the extent and distribution of plastic strain depend on the angle of maximum compressive principal stress. At larger angles, inelastic strain accumulates on the extensional side of a dynamically propagating rupture. At smaller angles, the extent of plasticity is limited to the compressional side of the domain. At smaller cohesion values, off-fault plasticity may occur during aseismic slip, which alters the nucleation characteristics and earthquake sequence pattern. Furthermore, our results at lower cohesion values indicate that plastic strain accumulation may occur in both the extensional and compressional sides of the off-fault bulk even at higher angles of maximum compression. In conclusion, this produces damage patterns that deviate from the traditional off-fault fan-like distribution observed in dynamic rupture simulations and emphasizes the significance of long-term deformation in interpreting observations.

58 GEOSCIENCES↗
DOE OSTI2025

SaltStone Wastewater Cement Study Using Isothermal Calorimetry, Standard Concrete Characterization Techniques, and CemGEMS - 25169

Cementitious reagents are used to solidify/stabilize aqueous radioactive, hazardous, and mixed salt solutions, and sludges to meet low-level radioactive waste (LLW) and Resource Conservation and Recovery Act (RCRA) requirements for disposal at Department of Energy (DOE). It is flexible enough to solidify radioactive wastewater saturated in complex species that include but are not limited to radioactive isotopes from the bombardment of neutrons in reactor operation, corrosion products from metallic components, and a variety of soluble organic compounds. [1,2]. Waste form testing typically includes processing or fresh properties, cured properties, compressive strength and hydraulic properties, porosity, density, saturated and unsaturated moisture transport, and leachability of contaminants in the waste form pore solution. Properties are collected over a relatively limited time, typically 28 to 365 days [3]. In addition, changes in the waste form as the result of time and changing conditions are important for concrete engineers to predict overall performance of the forms and potential release of contaminants in the disposal process via unintended filtration into the environment [4]. These predictions are determined/calculated characterizing young waste forms (relative to the standard age of concrete) and are based on transport through soluble ions in pore solutions. Characterization methods include X-ray, SEM, and isothermal calorimetry among other methods used to define the composition, amorphous vs. crystalline nature of the components, and the energetic formation mechanisms for multi-phase mineral systems. [5–7] Isothermal calorimetry is a well standardized technique for cements and concretes and can be used to predict the timing and nature of the hydration reactions.[8] The technique can measure long term energetic

Bustamante, Michael E. [Savannah River National La↗
DOE OSTI2025

Amplification of turbulence through multiple planar shocks

We study the amplification of isotropic, incompressible turbulence through multiple planar, collisional shocks, using analytical linear theory. There are two limiting cases we explore. The first assumes shocks occur rapidly in time such that the turbulence does not evolve between shocks. Whereas the second case allows enough time for turbulence to isotropize between each shock. For the latter case, through a quasi-equation-of-state, we show that the weak multishock limit is agnostic to the distinction between thermal and vortical turbulent pressures, like an isotropic volumetric compression. When turbulence does not return to isotropy between shocks, the generated anisotropy—itself a function of shock strength—can feedback on amplification by further shocks, altering choices for maximal or minimal amplification. In addition for this case, we find that amplification is sensitive to the shock ordering. As a result, we map how choices of shock strength can impact these amplification differences due to ordering, finding, for example, shock pairs which lead to identical mean postshock fields (density, temperature, pressure) but maximally distinct turbulent amplification.

Astrophysical fluid dynamics↗
DOE OSTI2023

Enhanced magnetostriction through dilute Ce doping of Fe-Ga

Doping of magnetostrictive galfenol (Fe 82 Ga 18 , in at.%) with rare-earth elements significantly enhances magnetostriction, with the largest gains achieved in textured melt-spun ribbons. Here, it is demonstrated that even extremely dilute Ce, as little as 65 ppm, can double the magnetostrictive response of galfenol when coupled with an appropriate heat treatment. This improvement is correlated with a compression of the host lattice, both of which reach their maximum extent at the calculated solubility limit of Ce in in body-centered cubic (bcc) galfenol, ~ 50 ppm. Beyond this point, excess Ce segregates into CeGa 2 , which forms an interdendritic network throughout the sample at high Ce levels and cannot be resolutionized through heat treatments. These findings point to the importance of solubility limits (i.e., equilibrium thermodynamics) in determining appropriate doping levels or heat treatment couples to optimize magnetostrictive performance, confirming that overdoping is actively detrimental to both material properties and cost.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Influence of gradation on failure mode of saturated sand at particle scale

Extensive research has been reported in the literature to characterize the failure mode of dry sand using various experimental techniques such as surface optical imaging, photo-elastic materials, three-dimensional (3D) computed tomography (CT), and 3D synchrotron micro-computed tomography (SMT). However, there is a limited literature about the behavior of saturated sand. This paper presents the results of axisymmetric triaxial compression (ATC) experiments that were conducted on saturated sand specimens. The behavior of specimens composed of a uniform sand with grain size between US sieves #40 and #50 is compared to specimens conducted on the same sand that has a wider gradation. 3D SMT technique was used to acquire 3D scans while shearing the specimens to probe localized events that are completely missed or misinterpreted when analyzing ATC measurements based on global standard measurements. The results show a higher effective principal stress ratio (EPSR) for the non-uniform specimen and a thicker shear band when compared to uniform specimen.

Elnur, Mohammed [University of Tennessee]↗
DOE OSTI2023

Parallel Implicit Hydrodynamics with Material Strength for High Explosive Burn Calculations

High explosives are almost always evolving in some form of metal containment vessel. This fact requires that a materials model for the evolution of the metal containment vessel be part of any simulation of the HE. Since the actual form of the strength model to be used is an open question, we incorporate the material strength properties in a relatively agnostic fashion, which will accommodate many strength models. The only restriction is that the stress components be a function of density, specific internal energy and velocities. In addition, the timescales and rates of the chemical reactions in the HE vary between thousands of seconds and nanoseconds. A hydrodynamics capable of operating in anticipation of the eventual violent release of energy via these chemical reactions is a necessity. The central issue in creating a hydrodynamics capable of spanning these timescales is to forgo the use of a Courant time step control necessary in an explicit hydrodynamics. The Courant time-step arises because of characteristic velocities associated with the material, such as the sound speed or, in materials with strength, characteristic longitudinal and transverse speeds associated with compression and shear. The method used to circumvent the need for a Courant time-step limit is to develop an implicit calculation of the advanced particle pressure and shear modulus derived from the conservation laws of mass, momentum and specific internal energy. This process creates the implicit hydrodynamics needed for the HE calculations of interest to this study.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Turboexpander for Direct Cooling in Hydrogen Vehicle Fueling Infrastructure

Hydrogen fuel cell electric vehicles (FCEVs) have been identified as one of a few options for zero carbon emissions transportation. A major advantage of FCEVs is that they can fuel quickly and follow a familiar fueling behavior to hydrocarbon-fueled vehicles. Whether light duty or heavy duty, the goal for a hydrogen dispenser is to fuel a vehicle in the same amount of time as the fossil fuel equivalent. When hydrogen is dispensed into the vehicle storage system, however, the temperature rises due to the Joule-Thomson effect and the heat of compression. Typically, vehicles store the compressed hydrogen in composite overwrapped pressure vessels that have a polymer liner with an operational temperature limit of 85°C. This temperature limit can be exceeded during fast fueling if hydrogen is not precooled. Precooling allows for a dispenser to fuel a vehicle at a faster flow rate by preventing the storage tank on the vehicle from overheating. Fueling protocols and requirements are presented in SAE J2601 Fueling Protocols for Light Duty Gaseous Hydrogen Surface Vehicles [1]. A heavy-duty equivalent is under development with similar requirements for precooling. Currently, conventional precooling for light-duty vehicle refueling uses a heat exchanger and chiller to cool the hydrogen gas to -40°C before entering the vehicle. The precooling system represents a significant part of the station capital and operating costs, so if the cost of the precooling system can be reduced by improving its efficiency, the overall station capital and operating cost can be reduced. In this project, National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL) researchers teamed up to investigate the turboexpander precooling application. A turboexpander is a device that places a turbine in a flow path where a pressure differential can be attained. This expansion device will extract work and lower the temperature of the fluid as the pressure reduces. While initial calculations based on established principles showed potential for a turboexpander to generate cooled gas, much work needs to be done to prove the concept. Turboexpanders typically work best under steady state conditions, while the dispenser is a very dynamic flow system. Dynamic turboexpander systems have been proven, such as a turbocharger on a gasoline vehicle. The inlet pressure at a dispenser is also much higher than any other known turboexpander system but should behave similarly to higher density fluids at lower pressures. Having both performed initial calculations, NREL and SNL researchers teamed up to investigate the turboexpander precooling application further. A project was soon built around the idea with SNL performing system modeling using previously proven capabilities and NREL performing hardware characterization with established station capabilities. Creare LLC was contracted as the turbomachinery expert to design and build the concept device. Part way through the project, however, contracting issues with the funding partner caused the project to terminate early before building and characterizing the concept device. While the project could not continue, many key findings were already learned. This paper is a summary of those findings.

08 HYDROGEN↗
DOE OSTI2021

Techno-Economic Analysis of a Concentrating Solar Power Plant Using Redox-Active Metal Oxides as Heat Transfer Fluid and Storage Media

We present results for a one-dimensional quasi-steady-state thermodynamic model developed for a 111.7 MW e concentrating solar power (CSP) system using a redox-active metal oxide as the heat storage media and heat transfer agent integrated with a combined cycle air Brayton power block. In the energy charging and discharging processes, the metal oxide CaAl 0.2 Mn 0.8 O 2.9-δ (CAM28) undergoes a reversible, high temperature redox cycle including an endothermic oxygen-releasing reaction and exothermic oxygen-incorporation reaction. Concentrated solar radiation heats the redox-active oxide particles under partial vacuum to drive the reduction extent deeper for increased energy density at a fixed temperature, thereby increasing storage capacity while limiting the required on sun temperature. Direct counter-current contact of the reduced particles with compressed air from the Brayton compressor releases stored chemical and sensible energy, heating the air to 1,200°C at the turbine inlet while cooling and reoxidizing the particles. The cool oxidized particles recirculate through the solar receiver subsystem for another cycle of heating and reduction (oxygen release). We applied the techno-economic model to 1) size components, 2) examine intraday operation with varying solar insolation, 3) estimate annual performance characteristics over a simulated year, 4) estimate the levelized cost of electricity (LCOE), and 5) perform sensitivity analyses to evaluate factors that affect performance and cost. Simulations use hourly solar radiation data from Barstow, California to assess the performance of a 111.7 MW e system with solar multiples (SMs) varying from 1.2 to 2.4 and storage capacities of 6–14 h. The baseline system with 6 h storage and SM of 1.8 has a capacity factor of 54.2%, an increase from 32.3% capacity factor with no storage, and an average annual energy efficiency of 20.6%. Calculations show a system with an output of 710 GWh e net electricity per year, 12 h storage, and SM of 2.4 to have an installed cost of $329 million, and an LCOE of 5.98 ¢/kWh e . This value meets the U.S. Department of Energy’s SunShot 2020 target of 6.0 ¢/kWh e ( U. S Department of Energy, 2012 ), but falls just shy of the 5.0 ¢/kWh e 2030 CSP target for dispatchable electricity ( U. S Department of Energy, 2017 ). The cost and performance results are minimally sensitive to most design parameters. However, a one-point change in the weighted annual cost of capital from 8 to 7% (better understood as a 12.5% change) translates directly to an 11% decrease (0.66 ¢/kWhe) in the LCOE.

Gorman, Brandon T.↗
DOE OSTI2022

High-Fidelity Mock Development for the Insensitive High Explosive TATB

Due to the violent reaction potential of high explosives, in tests where a reaction is not desired, it can be safe and convenient to use an inert mock that can mimic relevant properties of the associated explosive. Use of mock materials is well-established in explosives work, but most existing mocks are generally meant to mimic only one or two properties of a given explosive, potentially failing to match the explosive in other critical ways. Recently, there has been interest in developing robust thermomechanical mocks for many common explosives. Here, eleven materials are systematically chosen and investigated as potential thermomechanical mocks for TATB, the explosive component of PBX 9502. DSC, nanoindentation, and compression testing are used to narrow down to most appropriate mocks and identify their advantages and limitations. Hardness and elastic modulus are reported for the first time for the molecular crystals iodoanthranilic acid, hexamine, melamine, and trithiolane dioxide, and the crystal structure is reported for the first time for the molecular crystals iodoanthranilic acid and iodosalicylic acid.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Strategies for Determining the Cascade Rate in MHD Turbulence: Isotropy, Anisotropy, and Spacecraft Sampling

Exact laws for evaluating cascade rates, tracing back to the Kolmogorov "4/5" law, have been extended to many systems of interest including magnetohydrodynamics (MHD), and compressible flows of the magnetofluid and ordinary fluid types. It is understood that implementations may be limited by the quantity of available data and by the lack of turbulence symmetry. Assessment of the accuracy and feasibility of such third-order (or Yaglom) relations is most effectively accomplished by examining the von Kármán–Howarth equation in increment form, a framework from which the third-order laws are derived as asymptotic approximations. Using this approach, we examine the context of third-order laws for incompressible MHD in some detail. The simplest versions rely on the assumption of isotropy and the presence of a well-defined inertial range, while related procedures generalize the same idea to arbitrary rotational symmetries. Conditions for obtaining correct and accurate values of the dissipation rate from these laws based on several sampling and fitting strategies are investigated using results from simulations. The questions we address are of particular relevance to sampling of solar wind turbulence by one or more spacecraft.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Electron subband degeneracy heat pump for cryogenic cooling

An unconventional method of solid-state cryogenic cooling utilizing the electron subband degeneracy of semiconductor heterostructures is discussed in this Letter. The working principle of using the electrons as the working medium to perform cyclic heat pumping under electrostatic subband "expansion" and "compression" is discussed. The calculated base temperature can reach below dilution refrigeration temperatures with the fundamental limit set by electron-phonon interaction. Using an ultra-wide GaAs quantum well as an example, the cooling power per unit volume is estimated to reach $0.85\ \rm \mu W/cm^3$ at $25\ \rm mK$ with a hot-side temperature of $42.5\ \rm mK$, suitable for applications such as quantum computing.

Wang, Chulin↗
DOE OSTI2021

RapidClave® Technology Demonstrations - I

This demonstration sought to show a dramatic reduction in tool cost for RapidClave® tooling, taking advantage of recent modifications made on the RapidClave® system. Instead of building tools with complex internal heating, simple aluminum tools would be produced and heated externally through the recently added hot plate and air blower inside the RapidClave® system. Baselining against this tooling is the legacy RapidClave® tooling, as well as compression tooling, which would be the incumbent processing technique that the RapidClave® is displacing. Both an automotive and aerospace application were used to evaluate the tooling and process. Specifically, a four-piece Volkswagen hood structure was selected as an appropriate automotive geometry, while a wing structure representative of a current wing entering limited production was provided by Cornerstone Research Group for evaluating aerospace applications. In total, six tools were fabricated, and costs were compared against compression tooling quotes of the same tool geometry. A cost savings of over 80% was shown on all the tools. This demonstration also produced parts in the RapidClave® using the abovementioned tools to validate the low-cost tooling and the machine modifications. Solvay recommended two prepreg systems, CYCOM® EP2750 and SolvaLite™ 712, as appropriate for aerospace and automotive applications, respectively. Flat panels of each material were fabricated to verify cure parameters before proceeding with actual part fabrication. On-tool cycle times of approximately 30 minutes was achieved, with modifications identified to lower the time further.

36 MATERIALS SCIENCE↗
DOE OSTI2021

A novel in vivo mouse intervertebral disc degeneration model induced by compressive suture

Intervertebral disc degeneration (IDD) is the root cause of many musculoskeletal disorders of the spine. However, the etiology of IDD is complex and still not well understood. Animal models of IDD would be useful in deciphering the underlying mechanisms. But the existing animal models have their limitations. Therefore, to establish a novel mouse model that can simulate the human IDD process in vivo, we proposed to carefully circumcise the 2 mm-wide tail skin and then compressively sutured the defect with a simple end-to-end suture to exert excessive pressure on the disc. After 1-week, 2-week, and 4-week compression, the mice were sacrificed and the intervertebral discs were harvested for tissue analysis. The radiological, morphological, and molecular modifications of intervertebral discs were measured to characterize this model. Radiologically, the water content of the intervertebral disc decreased significantly after 2-week compression. Morphologically, the nucleus pulposus showed a decrease in volume and the number of notochordal cells. The compressive suture also broke the balance between anabolic and catabolic enzymes in nucleus pulposus, which led to the remodeling of the extracellular matrix in nucleus pulposus as the content of aggrecan and collagen II decreased. The compressive suture could induce intervertebral discs degeneration in a more reasonable way, which was solely influenced by mechanical loading, as the mice caudal vertebrae still moved freely after the operation. This kind of animal model could be adapted as a reliable in vivo mouse IDD model for the research regarding the etiology and treatments of IDD.

60 APPLIED LIFE SCIENCES↗