SEARCH · Engineering Papers
Results for “Developing”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Linkages between Policy and Business Innovation in the Development of China’s Energy Performance Contracting Market
China has a large and growing energy performance contracting (EPC) market, which has played a significant role in driving energy efficiency retrofits and improvements This paper evaluates how policies and business innovations have worked synergistically to expand China’s EPC market. We analyze the interconnected roles of four key factors: incentive policies, China’s Five-Year Plans, and business innovations in diversifying contract models and strengthening measurement and verification. We use multiple data sources for the analysis, including detailed information on business choices in 21 pilot projects, industry-wide surveys, and policy information. Our study indicates that supportive policies were important for the initial market development. As the market was established and continued to grow, the private sector started to take initiatives to address the issues that are left out of the policies, which helped overcome certain market barriers and enabled the sustainable growth of the market. Future policies could incorporate the successful innovations from the businesses to ensure long-term development of China’s EPC market. Understanding these policy and business drivers in a holistic way is critical to understanding how China was able to leverage its relatively small policy investments into much larger transformation of its existing buildings and industrial facilities through energy efficiency retrofits. This in turn can be informative for other countries seeking to achieve large-scale energy efficiency improvements.
Power grid simulation applications developed using the GridPACK™ high performance computing framework
Not Available
Impact of Alg3 Gene Deletion on Growth, Development, Pigment Production, Protein Secretion, and Functions of Recombinant Trichoderma reesei Cellobiohydrolases in Aspergillus niger
Abstract not provided
Using GeoRePORT to report socio-economic potential for geothermal development
Not Available
Structures of Vanadium-Containing Silicate and Borosilicate Glasses: Vanadium Potential Development and MD Simulations
Vanadium-containing multi-component glasses have been found with widely interests in various applications. However, the complex compositions, thus structures, lead to the challenges in experiments to understand the structural origin of the property change of these glasses. In this work, we developed compatible vanadium-related parameters for a widely used pair wise potential set to enable the simulations of the vanadium-containing multi-component glasses. Various crystal structures and glass compositions (with vanadium in different oxidation states) have been tested using the newly developed parameters, and structural information of cell parameters, pair distribution function, estimated bond distance, and coordination number have been obtained. The results are in good agreement with available experimental data, which indicates the new vanadium parameters can be used to simulate the vanadium-containing multi-component glasses and thus help study those applications with wide interests.
Modeling and Testing Miniature Torsion Specimens for SiC Joining Development Studies for Fusion
The international fusion community has designed a miniature torsion specimen for neutron irradiation studies of joined SiC and SiC/SiC composite materials. Miniature torsion joints based on this specimen design were fabricated using displacement reactions between Si and TiC to produce Ti3SiC2 + SiC joints with CVD-SiC and tested in torsion-shear prior to and after neutron irradiation. However, many of these miniature torsion specimens fail out-of-plane within the CVD-SiC specimen body, which makes it problematic to assign a shear strength value to the joints and makes it difficult to compare unirradiated and irradiated joint strengths to determine the effects of the irradiation. Finite element elastic damage and elastic-plastic damage models of miniature torsion joints are developed that indicate shear fracture is likely to occur within the body of the joined sample and cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. The model results are compared and discussed with regard to unirradiated and irradiated joint test data for a variety of joint materials. The unirradiated data includes Ti3SiC2 + SiC/CVD-SiC joints with tailored joint moduli, and includes steel/epoxy and CVD-SiC/epoxy joints. The implications for joint data based on this sample design are discussed.
Development of PRIME for irradiation performance analysis of U-Mo/Al dispersion fuel
Not Available
Draft Genome Sequence of Mentha longifolia and Development of Resources for Mint Cultivar Improvement
The genus Mentha encompasses species cultivated for their essential oils, which are formulated into a vast array of consumer products. Desirable oil characteristics and resistance to the fungal disease Verticillium wilt are top priorities for the mint industry. However, cultivated mints have complex polyploid genomes and are sterile. Breeding efforts, therefore, require the development of genomic resources for fertile mint species. Here, we present draft de novo genome and plastome assemblies for a wilt-resistant South African accession of Mentha longifolia (L.) Huds., a diploid species ancestral to cultivated peppermint and spearmint. The 353 Mb contained 35,597 predicted protein-coding genes, including 292 disease resistance gene homologs, and nine genes determining essential oil characteristics. A genetic linkage map ordered 1,397 genome scaffolds on 12 pseudochromosomes. Over two million simple sequence repeats were identified, which will aid molecular marker development. The M. longifolia genome is a valuable resource for both metabolic engineering and molecular breeding. This is exemplified by employing the genome sequence to clone and functionally characterize promoters in a peppermint cultivar, and demonstrating the utility of a glandular trichome-specific promoter to increase expression of a biosynthetic gene, thereby modulating essential oil composition.
Temperature effect of elastic anisotropy and internal strain development in advanced nanostructured alloys: An in-situ synchrotron X-ray investigation
Nanostructured ferritic alloys (NFAs) are a promising structural material for advanced nuclear systems due to their exceptional radiation tolerance and high-temperature mechanical properties. Their remarkable properties result from the ultrafine ultrahigh density Y-Ti-O nanoclusters dispersed within the ferritic matrix. In this work, we performed in-situ synchrotron X-ray diffraction tests to study the tensile deformation process of the three types of NFAs: 9YWTV, 14YWT-sm13, and 14YWT-sm170 at both room temperature and elevated temperatures. A technique was developed, combining Kroner’s model and X-ray measurement, to determine the intrinsic monocrystal elastic-stiffness constants, and polycrystal Young’s modulus and Poisson’s ratio of the NFAs. Temperature dependence of elastic anisotropy was observed in the NFAs. An analysis of intergranular strain and strengthening factors determined that 14YWT-sm13 had a higher resistance to temperature softening compared to 9YWTV, attributed to the more effective nanoparticle strengthening during high-temperature mechanical loading.
A General Strategy for Batch Development of High-Performance and Cost-Effective Sodium Layered Cathodes
High-performance and low-cost transition metal (TM) layered oxides using earth abundant elements are promising cathodes for Na-ion batteries. However, it is challenging to obtain desired materials because the large Na size, different Na occupations and various layer stacking sequences multiply the complication in determining the structure of a given composition and exacerbate uncertainty to the structure-property correlation. In this work, we use the attainment of desired NaxMnyNiZTM1-y-zO2-based cathode materials as an example to demonstrate a general roadmap for batch development of sodium layered cathodes towards practical applications. A synthesis phase diagram of NaxMnyNi1-yO2 was created for pre-screening and rational selection of the platform material of P2/O3-structured Na0.85Mn0.6Ni0.4O2. Cationic potential was leveraged in elemental substitution to further promote the material structural stability and electrochemical performance. Several cost-effective O3 and P2/O3 hybrid cathode materials have been obtained, all of which demonstrate excellent performance. In particular, the Na0.85Mn0.5Ni0.4Ti0.1O2 delivers a high specific capacity of ~130 mAh/g between 2-4 V and 91% retention after 500 cycles. The work discovers multiple materials as high-performance and cost-effective Na-ion battery cathodes and offers critical guidance to the rational design of future layered cathode materials.
Infrastructure development for radioactive materials at the NSLS-II
The X-ray Powder Diffraction (XPD) Beamline at the National Synchrotron Light Source-II is a multipurpose instrument designed for high-resolution, high-energy X-ray scattering techniques. In this article, the capabilities, opportunities and recent developments in the characterization of radioactive materials at XPD are described. The overarching goal of this work is to provide researchers access to advanced synchrotron techniques suited to the structural characterization of materials for advanced nuclear energy systems. XPD is a new beamline providing high photon flux for X-ray Diffraction, Pair Distribution Function analysis and Small Angle X-ray Scattering. The infrastructure and software described here extend the existing capabilities at XPD to accommodate radioactive materials. Such techniques will contribute crucial information to the characterization and quantification of advanced materials for nuclear energy applications. We describe the automated radioactive sample collection capabilities and recent X-ray Diffraction and Small Angle X-ray Scattering results from neutron irradiated reactor pressure vessel steels and oxide dispersion strengthened steels.
Development of activity–descriptor relationships for supported metal ion hydrogenation catalysts on silica
With the increasing attention on single-site heterogeneous catalysts on account of their high specific activity, more effective catalyst design strategies are necessary. We demonstrate a first-principles-calculation-guided active-site design strategy for alkene hydrogenation using silica-supported single-atom single-site heterogeneous catalysts (SSHCs, i.e., M/SiO2). An activity-descriptor relationship for propylene hydrogenation was established using representative catalysts (i.e., Ga3+, Zn2+, Mn2+ and Ti4+/SiO2), correlating the computational activity descriptor (i.e., the reaction free energy of the metal hydride formation) with the experimental reaction rates. Microkinetic modeling confirmed the predicted reaction mechanisms and further explained the rationale of the activity-descriptor relationship. This relationship was then used to predict the trend of activities of a variety of isolated ions on silica, and an In3+/SiO2 catalyst was identified as the most promising candidate based on its predicted activity and synthetic feasibility. The monodispersed In3+/SiO2 catalyst was then synthesized, for the first time, and showed higher propylene hydrogenation activity than the other four single-atom SSHCs, as predicted. Detailed spectroscopic characterization (XAS, XPS, DRIFTS and DRUV-Vis) provided insights into coordination environments and oxidation states of the catalysts, as well as evidence for the hydride intermediate. The successful discovery of the In3+/SiO2 catalyst for propylene hydrogenation using the first-principles-calculations-guided design strategy opens up new opportunities for efficient development of single-atom SSHCs.
Development of a physiologically based pharmacokinetic model for assessment of human exposure to bisphenol A
A previously developed physiologically based pharmacokinetic (PBPK) model for bisphenol A (BPA) in adult rhesus monkeys was modified to characterize the pharmacokinetics of BPA and its phase II conjugates in adult humans following oral ingestion. Coupled with in vitro studies on BPA metabolism in the liver and the small intestine, the PBPK model was parameterized using oral pharmacokinetic data with deuterated-BPA (d{sub 6}-BPA) delivered in cookies to adult humans after overnight fasting. The availability of the serum concentration time course of unconjugated d{sub 6}-BPA offered direct empirical evidence for the calibration of BPA model parameters. The recalibrated PBPK adult human model for BPA was then evaluated against published human pharmacokinetic studies with BPA. A hypothesis of decreased oral uptake was needed to account for the reduced peak levels observed in adult humans, where d{sub 6}-BPA was delivered in soup and food was provided prior to BPA ingestion, suggesting the potential impact of dosing vehicles and/or fasting on BPA disposition. With the incorporation of Monte Carlo analysis, the recalibrated adult human model was used to address the inter-individual variability in the internal dose metrics of BPA for the U.S. general population. Model-predicted peak BPA serum levels were in the range of pM, with 95% of human variability falling within an order of magnitude. This recalibrated PBPK model for BPA in adult humans provides a scientific basis for assessing human exposure to BPA that can serve to minimize uncertainties incurred during extrapolations across doses and species. - Highlights: • A PBPK model predicts the kinetics of bisphenol A (BPA) in adult humans. • Serum concentrations of aglycone BPA are available for model calibration. • Model predicted peak BPA serum levels for adult humans were in the range of pM. • Model predicted 95% of human variability fell within an order of magnitude.
Development of a PBPK model of thiocyanate in rats with an extrapolation to humans: A computational study to quantify the mechanism of action of thiocyanate kinetics in thyroid
Thyroid homeostasis can be disturbed due to thiocyanate exposure from the diet or tobacco smoke. Thiocyanate inhibits both thyroidal uptake of iodide, via the sodium-iodide symporter (NIS), and thyroid hormone (TH) synthesis in the thyroid, via thyroid peroxidase (TPO), but the mode of action of thiocyanate is poorly quantified in the literature. The characterization of the link between intra-thyroidal thiocyanate concentrations and dose of exposure is crucial for assessing the risk of thyroid perturbations due to thiocyanate exposure. We developed a PBPK model for thiocyanate that describes its kinetics in the whole-body up to daily doses of 0.15 mmol/kg, with a mechanistic description of the thyroidal kinetics including NIS, passive diffusion, and TPO. The model was calibrated in a Bayesian framework using published studies in rats. Goodness-of-fit was satisfactory, especially for intra-thyroidal thiocyanate concentrations. Thiocyanate kinetic processes were quantified in vivo, including the metabolic clearance by TPO. The passive diffusion rate was found to be greater than NIS-mediated uptake rate. The model captured the dose-dependent kinetics of thiocyanate after acute and chronic exposures. Model behavior was evaluated using a Morris screening test. The distribution of thiocyanate into the thyroid was found to be determined primarily by the partition coefficient, followed by NIS and passive diffusion; the impact of the latter two mechanisms appears to increase at very low doses. Extrapolation to humans resulted in good predictions of thiocyanate kinetics during chronic exposure. The developed PBPK model can be used in risk assessment to quantify dose-response effects of thiocyanate on TH. - Highlights: • A PBPK model of thiocyanate (SCN{sup −}) was calibrated in rats in a Bayesian framework. • The intra-thyroidal kinetics of thiocyanate including NIS and TPO was modeled. • Passive diffusion rate for SCN{sup −} seemed to be greater than the NIS-mediated uptake. • The dose-dependent kinetics of SCN{sup −} was captured after an acute and chronic exposure. • The PBPK model of thiocyanate was successfully extrapolated to humans.
Development of a cyanobacterial heterologous polyketide production platform
Not provided.
Development and Scale-up of Continuous Electrocatalytic Hydrogenation of Functionalized Nitro arenes, Nitriles and Unsaturated Aldehydes
Electrolysis reactors based on the filter-press architecture of redox flow batteries have proven to be effective and scalable towards the production of commercially relevant, pharmaceutical quantities of anilines (>500 kg/year) from halogen-, hydroxyl-, and carbonyl-substituted nitroarenes. Turbulent flow through the carbon felts on which the catalysts were supported facilitated scaling towards production levels because it conferred on the reactors scale-independent, plug flow-like residence time distributions and high mass transfer coefficients. Equipping the cells with micro-reference electrodes made it possible to transfer reaction conditions first developed in batch systems to the continuous flow reactors. The catalysts prepared by incipient wetness impregnation of metal salts into lightly oxidized carbon felt supports were readily generalizable.