Energy-Conserving Pseudo-spectral Particle-in-Cell Methods
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Positron Emission Tomography Imaging of Cell Trafficking: A Method of Cell Radiolabeling
Not provided.
Science & Technology - Other Topics↗
Solar sensor having coarse and fine sensing with matched preirradiated cells and method of selecting cells Patent
Solar sensor with coarse and fine sensing elements for matching preirradiated cells on degradation rates
Fontana, A.↗
Methods for immortalization of epithelial cells
Methods for inducing non-clonal immortalization of normal epithelial cells by directly targeting the two main senescence barriers encountered by cultured epithelial cells. In finite lifespan pre-stasis human mammary epithelial cells (HMEC), the stress-associated stasis barrier was bypassed, and in post-stasis HMEC, the replicative senescence barrier, a consequence of critically shortened telomeres, was bypassed. Early passage non-clonal immortalized lines exhibited normal karyotypes. Methods of efficient HMEC immortalization, in the absence of “passenger” genomic errors, should facilitate examination of telomerase regulation and immortalization during human carcinoma progression, methods for screening for toxic and environmental effect on progression, and the development of therapeutics targeting the process of immortalization.
59 BASIC BIOLOGICAL SCIENCES↗
A study of short test and charge retention test methods for nickel-cadmium spacecraft cells
Methods for testing nickel-cadmium cells for internal shorts and charge retention were studied. Included were (a) open circuit voltage decay after a brief charge, (b) open circuit voltage recovery after shorting, and (c) open circuit voltage decay and capacity loss after a full charge. The investigation included consideration of the effects of prior history, of conditioning cells prior to testing, and of various test method variables on the results of the tests. Sensitivity of the tests was calibrated in terms of equivalent external resistance. The results were correlated. It was shown that a large number of variables may affect the results of these tests. It is concluded that the voltage decay after a brief charge and the voltage recovery methods are more sensitive than the charged stand method, and can detect an internal short equivalent to a resistance of about (10,000/C)ohms where "C' is the numerical value of the capacity of the cell in ampere hours.
Scott, W. R.↗
Multiscale Static Analysis of Notched and Unnotched Laminates Using the Generalized Method of Cells
The generalized method of cells (GMC) is demonstrated to be a viable micromechanics tool for predicting the deformation and failure response of laminated composites, with and without notches, subjected to tensile and compressive static loading. Given the axial [0], transverse [90], and shear [+45/-45] response of a carbon/epoxy (IM7/977-3) system, the unnotched and notched behavior of three multidirectional layups (Layup 1: [0,45,90,-45](sub 2S), Layup 2: [0,60,0](sub 3S), and Layup 3: [30,60,90,-30, -60](sub 2S)) are predicted under both tensile and compressive static loading. Matrix nonlinearity is modeled in two ways. The first assumes all nonlinearity is due to anisotropic progressive damage of the matrix only, which is modeled, using the multiaxial mixed-mode continuum damage model (MMCDM) within GMC. The second utilizes matrix plasticity coupled with brittle final failure based on the maximum principle strain criteria to account for matrix nonlinearity and failure within the Finite Element Analysis--Micromechanics Analysis Code (FEAMAC) software multiscale framework. Both MMCDM and plasticity models incorporate brittle strain- and stress-based failure criteria for the fiber. Upon satisfaction of these criteria, the fiber properties are immediately reduced to a nominal value. The constitutive response for each constituent (fiber and matrix) is characterized using a combination of vendor data and the axial, transverse, and shear responses of unnotched laminates. Then, the capability of the multiscale methodology is assessed by performing blind predictions of the mentioned notched and unnotched composite laminates response under tensile and compressive loading. Tabulated data along with the detailed results (i.e., stress-strain curves as well as damage evolution states at various ratios of strain to failure) for all laminates are presented.
GMC↗
Method of fabricating an emitter region of a solar cell
Methods of fabricating emitter regions of solar cells are described. Methods of forming layers on substrates of solar cells, and the resulting solar cells, are also described.
14 SOLAR ENERGY↗
Methods of forming interdigitated back contact solar cells
Methods for forming interdigitated back contact solar cells from III-V materials are provided. According to an aspect of the invention, a method includes depositing a patterned Zn layer to cover first areas of an n-type emitter region, wherein the emitter region comprises a III-V material, and forming a passivated back contact region by counter-doping the first areas of the emitter region by diffusing Zn from the patterned Zn layer into the first areas of the emitter region, such that the first areas of the emitter region become p-type.
14 SOLAR ENERGY↗
Electrochemical cells and methods of manufacturing the same
Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus, the intermediate layer can serve as a current collector for the electrochemical cell.
25 ENERGY STORAGE↗
Electrochemical cells and methods of manufacturing the same
Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus, the intermediate layer can serve as a current collector for the electrochemical cell.
Bazzarella, Ricardo↗
Electrochemical cells and methods of manufacturing the same
Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus, the intermediate layer can serve as a current collector for the electrochemical cell.
Bazzarella, Ricardo↗
Electrochemical cells and methods of manufacturing the same
Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus, the intermediate layer can serve as a current collector for the electrochemical cell.
Bazzarella, Ricardo↗
Regular sensitivity computation avoiding chaotic effects in particle-in-cell plasma methods
Particle-in-cell (PIC) simulation methods are attractive for representing species distribution functions in plasmas. However, as a model, they introduce uncertain parameters, and for quantifying their prediction uncertainty it is useful to be able to assess the sensitivity of a quantity-of-interest (QoI) to these parameters. Such sensitivity information is likewise useful for optimization. However, computing sensitivity for PIC methods is challenging due to the chaotic particle dynamics, and sensitivity techniques remain underdeveloped compared to those for Eulerian discretizations. This challenge is examined from a dual particle–continuum perspective that motivates a new sensitivity discretization. Two routes to sensitivity computation are presented and compared: a direct fully-Lagrangian particle-exact approach provides sensitivities of each particle trajectory, and a new particle-pdf discretization, which is formulated from a continuum perspective but discretized by particles to take the advantages of the same type of Lagrangian particle description leveraged by PIC methods. Since the sensitivity particles in this approach are only indirectly linked to the plasma-PIC particles, they can be positioned and weighted independently for efficiency and accuracy. The corresponding numerical algorithms are presented here in mathematical detail. The advantage of the particle-pdf approach in avoiding the spurious chaotic sensitivity of the particle-exact approach is demonstrated for Debye shielding and sheath configurations. In essence, the continuum perspective makes implicit the distinctness of the particles, which circumvents the Lyapunov instability of the N -body PIC system. The cost of the particle-pdf approach is comparable to the baseline PIC simulation.
70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
Metallization of conductive wires for solar cells
Methods of fabricating a solar cell, and system for electrically coupling solar cells, are described. In an example, the methods for fabricating a solar cell can include placing conductive wires in a wire guide, where conductive wires are placed over a first semiconductor substrate having first doped regions and second doped regions. The method can include aligning the conductive wires over the first and second doped regions, where the wire guide aligns the conductive wires substantially parallel to the first and second doped regions. The method can include bonding the conductive wires to the first and second doped regions. The bonding can include applying a mechanical force to the semiconductor substrate via a roller or bonding head of the wire guide, where the wire guide inhibits lateral movement of the conductive wires during the bonding.
Sewell, Richard Hamilton↗
Progressive Failure of a Unidirectional Fiber-Reinforced Composite Using the Method of Cells: Discretization Objective Computational Results
The smeared crack band theory is implemented within the generalized method of cells and high-fidelity generalized method of cells micromechanics models to capture progressive failure within the constituents of a composite material while retaining objectivity with respect to the size of the discretization elements used in the model. An repeating unit cell containing 13 randomly arranged fibers is modeled and subjected to a combination of transverse tension/compression and transverse shear loading. The implementation is verified against experimental data (where available), and an equivalent finite element model utilizing the same implementation of the crack band theory. To evaluate the performance of the crack band theory within a repeating unit cell that is more amenable to a multiscale implementation, a single fiber is modeled with generalized method of cells and high-fidelity generalized method of cells using a relatively coarse subcell mesh which is subjected to the same loading scenarios as the multiple fiber repeating unit cell. The generalized method of cells and high-fidelity generalized method of cells models are validated against a very refined finite element model.
Pineda, Evan J.↗
Tumor-Initiating Cells and Methods of Use
Provided herein are an isolated or enriched population of tumor initiating cells derived from normal cells, cells susceptible to neoplasia, or neoplastic cells. Methods of use of the cells for screening for anti-hyperproliferative agents, and use of the cells for animal models of hyperproliferative disorders including metastatic cancer, diagnostic methods, and therapeutic methods are provided.
Hlatky, Lynn↗
On the Finite Element Implementation of the Generalized Method of Cells Micromechanics Constitutive Model
The Generalized Method of Cells (GMC), a micromechanics based constitutive model, is implemented into the finite element code MARC using the user subroutine HYPELA. Comparisons in terms of transverse deformation response, micro stress and strain distributions, and required CPU time are presented for GMC and finite element models of fiber/matrix unit cell. GMC is shown to provide comparable predictions of the composite behavior and requires significantly less CPU time as compared to a finite element analysis of the unit cell. Details as to the organization of the HYPELA code are provided with the actual HYPELA code included in the appendix.
Wilt, T. E.↗
Comparison of the Computational Efficiency of the Original Versus Reformulated High-Fidelity Generalized Method of Cells
The High-Fidelity Generalized Method of Cells (HFGMC) micromechanics model has recently been reformulated by Bansal and Pindera (in the context of elastic phases with perfect bonding) to maximize its computational efficiency. This reformulated version of HFGMC has now been extended to include both inelastic phases and imperfect fiber-matrix bonding. The present paper presents an overview of the HFGMC theory in both its original and reformulated forms and a comparison of the results of the two implementations. The objective is to establish the correlation between the two HFGMC formulations and document the improved efficiency offered by the reformulation. The results compare the macro and micro scale predictions of the continuous reinforcement (doubly-periodic) and discontinuous reinforcement (triply-periodic) versions of both formulations into the inelastic regime, and, in the case of the discontinuous reinforcement version, with both perfect and weak interfacial bonding. The results demonstrate that identical predictions are obtained using either the original or reformulated implementations of HFGMC aside from small numerical differences in the inelastic regime due to the different implementation schemes used for the inelastic terms present in the two formulations. Finally, a direct comparison of execution times is presented for the original formulation and reformulation code implementations. It is shown that as the discretization employed in representing the composite repeating unit cell becomes increasingly refined (requiring a larger number of sub-volumes), the reformulated implementation becomes significantly (approximately an order of magnitude at best) more computationally efficient in both the continuous reinforcement (doubly-periodic) and discontinuous reinforcement (triply-periodic) cases.
Arnold, Steven M↗