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DOE OSTI2020

Status Report on ASME Code Development for Nonmetallic Core Components in 2020

The purpose of this report is to provide a status update on the progress and ongoing activities of the current ASME Boiler Pressure Vessel (BPV) Code Section III, Division 5, on nonmetallic core components and assemblies which includes the design rules for graphite and ceramic composite materials. Section III is concerned with the design and construction of nuclear reactor components and Division 5 focuses on high temperature reactors (HTR). The ASME Section III Committee’s function for nuclear items other than pressure-retaining components, is to establish rules of safety related to structural integrity. The term “construction” refers to the all-inclusive effort comprising of materials, design, fabrication, examination, inspection, testing, certification, and pressure relief. The Department of Energy (DOE) supports industry codes and standards development through focused research providing the technical basis for new or modified codes and standards and the participation of subject matter experts in codes and standards committees. The activities for the nonmetallic core components and assemblies committees are the pursuit of two working groups that meet quarterly during ASME BPV Code Week meetings. The two working groups are General Requirements for Graphite and Ceramic Composite Core Components and Assemblies (GR GCCCCA) and Nonmetallic Design and Materials (NDM). The rules on general requirements for nonmetallic core components are discussed in the articles of Subsection HA subpart B. Ceramic composites were recently incorporated within the rules, and the GR GCCCCA working group is now in the process of aligning the requirements with the subsections and articles of ASME BPV Code Section III NCA, the general requirements for Division 1 and 2 of the code. The NDM working group is concerned with the design rules for graphite and composite materials for core components and assemblies discussed in Subsection HH (Class SN Nonmetallic Core Components) subpart A and subpart B which reference graphite and composite materials respectively. The bulk of the progress and work is done within this working group. A significant undertaking, with discussion that started in 2015, is to gain endorsement of ASME Section III, Division 5, by the U.S. Nuclear Regulatory Commission (NRC). In June 2018, ASME formally recommended endorsement to the NRC. The NRC has since initiated the endorsement review process, which is to be concluded early in 2021. ASME task groups on metallic structures and components, as well as non-metallic core support structures, have been formed to define potential pathways and schedules for NRC endorsement of Division 5. NRC determined to perform a review on the 2017 edition of Section III Division 5 as a baseline. As a result, the use of graphite as nonmetallic core components formed part of the review, but it excluded composite materials (which were first introduced in the 2019 edition). This report documents progress in FY 2020 directed toward ASME’s efforts to develop design codes for graphite and composites. Progress includes a major code review by NRC, the first code enquiry, and its solution, an overhaul of the treatment of Weibull Statistics, and the addition of Nonmandatory Appendices to the composites code relating to carbon-carbon composite materials.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2019

Effect of Ca Doping on the Structure and Magnetic and Electronic Properties of La{sub 1 − x}Ca{sub x}Cr{sub 0.8}Cu{sub 0.2}O{sub 3} (x = 0~0.3)

A series of La{sub 1 − x}Ca{sub x}Cr{sub 0.8}Cu{sub 0.2}O{sub 3} samples were successfully prepared by sol-gel method, and their crystal structures were refined by using X-ray powder diffraction data. All samples had orthorhombic structure with a space group Pbnm. Two magnetic transitions were observed for all of samples, and the paramagnetism-antiferromagnetism transition temperature decreased, and the antiferromagnetism-ferromagnetism transition temperature increased with increasing Ca content. Moreover, Cu and Ca co-doping improved conductivity and active energy.

36 MATERIALS SCIENCE↗

DOE OSTI2026

Climatic imprint on interfacially-controlled platinum-palladium resources

Abstract Iron oxide-rich laterites, soils, and regolith formed from the weathering of ultramafic rocks represent untapped unconventional resources for the critical minerals platinum and palladium, but the fundamental surficial geochemistry of these elements remains poorly understood. Depletion of Pd relative to Pt occurs in some weathering zones in semi-arid climates. The accepted model attributes this platinum-palladium chemical fractionation to preferential complexation of Pd by dissolved chloride. However, similar fractionation is not observed in laterites of humid equatorial regions despite substantial wet deposition of chloride. The established mechanistic model for Pt and Pd behavior during weathering thus inaccurately predicts the distribution of these critical minerals in many settings, hindering global resource assessment. We show through mineral-fluid partitioning experiments coupled to element-specific spectroscopy that this canonical explanation for platinum-palladium fractionation is invalid: chloride complexation does not differentially mobilize Pd versus Pt. Instead, mineral-specific interfacial reactions control Pd and Pt accumulation. Modeling of platinum-palladium fractionation in representative weathering zone profiles demonstrates sub-equal retention in goethite-rich settings and Pd depletion in hematite-rich zones, accurately predicting trends observed in soils and laterites. Iron oxide mineralogy, reflecting modern and past regional climate conditions, is likely the primary determinant of Pt and Pd endowment in weathering zone resources. This new model for Pt and Pd mobilization and accumulation behavior provides a mechanistic foundation for exploration and recovery of platinum group elements from novel ultramafic regolith deposits.

58 GEOSCIENCES↗

DOE OSTI2025

[LCA UP] LNG Ocean Shipping

This unit process includes operation of a liquefied natural gas (LNG) ocean tanker using steam, DFDE/TFDE, ME-GI or X-DF engines. The tanker is fueled by a combination of boil-off gas (BOG) produced via evaporation of LNG, fuel oil, and diesel.

Group - Transport Process; LCA; LCA Unit Process; ↗

DOE OSTI2025

Packages of Distributed Energy Technologies Demonstrating Demand Flexibility at Community Scale

The combination of increased electric load growth across all sectors, deferred electrical infrastructure investment, and other factors resulting in variable electric power supply, has created technical challenges to maintaining a resilient and reliable grid. Many federal, regional, and local efforts are in play to modernize the electric grid, including advancing building technologies and distributed energy resources (DERs) that are utilizing smarter controls to become responsive to both occupant and grid needs. This report reviews ten pilot projects demonstrating how groups of buildings combined with behind-the-meter (BTM) DERs such as electric vehicle (EV) charging, battery storage, flexible HVAC and domestic hot water systems, and photovoltaic systems can reliably and cost effectively provide grid services. Each of the ten pilot projects aim to deliver both energy efficiency and demand flexibility (DF) while supporting load growth. The ten demonstration teams are piloting flexible DER packages across diverse communities of residential and commercial buildings to address a variety of regional grid needs. The outcomes of these pilot projects will be used to inform future scaling through utility program development. This paper characterizes the ten teams, showcasing the decision-making process used by each group to develop their packages (Section 2), the grid services they plan to deliver (Section 3), the types of DER packages selected for deployment within building sectors (Section 4) and trends between building sector, DER types, and grid services In order to achieve community scale benefits, the pilot projects must utilize aggregated control mechanisms for coordinating buildings and DERs together. Several types of coordinated control architectures have evolved amongst the teams, influenced by use type, existing market conditions, and integration type. Three coordinated controls architectures have been characterized, highlighting their use cases, benefits, challenges, and tradeoffs in their design. These insights can aid utilities, control vendors, and developers in scaling community-level energy systems (Paul, 2024). Ultimately, the technology packages selected by the ten teams will be coordinated to provide power system services, also known as grid services. Insights from these demonstrations will be useful for grid operators, regulators, aggregators and other stakeholders as they look to deploy demand flexible resources as grid services in the future. The grid services that each team is targeting for demonstration are described in Section 3 and Section 4. Methods for evaluating the grid services have been described in the paper Metrics for Evaluating Grid Service Provision from Communities of Grid-interactive and Efficient Buildings and other DER (MacDonald, 2023). To identify technology packages for demonstration, Section 2 shows that project teams used a range of analysis approaches, including building energy modeling, AMI data analysis, cost-benefit frameworks, and utility pilot data. Some teams emphasized technical modeling to quantify grid impacts and demand reduction potential, while others prioritized economic evaluations, stakeholder input, or exploratory pilots to inform deployment decisions. This diversity reflects the need to tailor selection methods to project goals, available data, and organizational context. Section 5 discusses trends between the DER technologies deployed and the grid service provisions from each team. Residential buildings (multifamily and single family) lean towards technologies that enhance energy efficiency (e.g. weatherization upgrades, smart thermostats) and onsite power generation integration (e.g. solar PV). Commercial building demonstrations prioritize technologies that ensure operational reliability (e.g. battery storage) and centralized energy management systems and optimization solutions. Teams that are deploying controllable storage-based technologies are more likely to provide grid services that require a near real-time response. Teams incorporating load shifting technologies like smart thermostats with HEMs are likely to include energy markets participation and customer bill management offerings. Campus demonstrations are adopting diverse sets of DERs to emphasize renewable generation, paired with centralized control. This section also describes technologies that were considered during project planning but ultimately excluded from final deployment. These demonstrations reveal that effective DER package design should be tailored to building type, customer segment, and construction vintage. Multifamily buildings benefit from centralized HVAC upgrades and supervisory controls, while single-family homes are well-suited for individualized technologies like solar, storage, and smart home energy monitors. Commercial and campus settings prioritize EMIS integration and load optimization. New construction enables cost-effective integration of DER-ready infrastructure, whereas retrofits require deployments aligned with owner and tenant value streams. For utility program planners, early coordination with developers and building owners, paired with segmented and modular program offerings, can improve adoption, scalability, and grid impact.

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2012

Hydroxylation of p-substituted phenols by tyrosinase: Further insight into the mechanism of tyrosinase activity

Highlights: Black-Right-Pointing-Pointer The action the copper complexes and tyrosinase on phenols is equivalent. Black-Right-Pointing-Pointer Isotope effect showed that nucleophilic attack to copper atom may be the slower step. Black-Right-Pointing-Pointer The value of {rho} (Hammett constant) supports an electrophilic aromatic substitution. Black-Right-Pointing-Pointer Data obtained in steady state pH 7 conditions support the mechanism of Scheme 1SM. -- Abstract: A study of the monophenolase activity of tyrosinase by measuring the steady state rate with a group of p-substituted monophenols provides the following kinetic information: k{sub cat}{sup m} and the Michaelis constant, K{sub M}{sup m}. Analysis of these data taking into account chemical shifts of the carbon atom supporting the hydroxyl group ({delta}) and {sigma}{sub p}{sup +}, enables a mechanism to be proposed for the transformation of monophenols into o-diphenols, in which the first step is a nucleophilic attack on the copper atom on the form E{sub ox} (attack of the oxygen of the hydroxyl group of C-1 on the copper atom) followed by an electrophilic attack (attack of the hydroperoxide group on the ortho position with respect to the hydroxyl group of the benzene ring, electrophilic aromatic substitution with a reaction constant {rho} of -1.75). These steps show the same dependency on the electronic effect of the substituent groups in C-4. Furthermore, a study of a solvent deuterium isotope effect on the oxidation of monophenols by tyrosinase points to an appreciable isotopic effect. In a proton inventory study with a series of p-substituted phenols, the representation of k{sub cat}{sup f{sub n}}/k{sub cat}{sup f{sub 0}} against n (atom fractions of deuterium), where k{sub cat}{sup f{sub n}} is the catalytic constant for a molar fraction of deuterium (n) and k{sub cat}{sup f{sub 0}} is the corresponding kinetic parameter in a water solution, was linear for all substrates. These results indicate that only one of the proton transfer processes from the hydroxyl groups involved the catalytic cycle is responsible for the isotope effects. We suggest that this step is the proton transfer from the hydroxyl group of C-1 to the peroxide of the oxytyrosinase form (E{sub ox}). After the nucleophilic attack, the incorporation of the oxygen in the benzene ring occurs by means of an electrophilic aromatic substitution mechanism in which there is no isotopic effect.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2012

Evaluation of Invertebrate Bioaccumulation of Fly Ash Contaminants in the Emory, Clinch, and Tennessee Rivers, 2009 – 2010

This report provides a summary of results from studies on invertebrate bioaccumulation of potential contaminants associated with a major fly ash spill into the Emory River following the failure of a dike at the Tennessee Valley Authority's (TVA) Kingston Fossil Plant (KIF) in Kingston, Tennessee, in late December 2008. Data included in this report cover samples collected in calendar years 2009 and 2010. Samples collected from most sites in 2009 were processed by two different laboratories using different approved U.S. Environmental Protection Agency (EPA) analytical methods: ALS Laboratory Group in Ft. Collins, CO, processed sampling using EPA method 6010 (but method 6020 for uranium and SW7470 for mercury), and PACE Analytical in Minneapolis, MN, used EPA method 6020. A preliminary evaluation of results from both laboratories indicated that some differences exited in measured concentrations of several elements, either because of specific differences of the two methods or inter-laboratory differences. While concentration differences between the laboratories were noted for many elements, spatial trends depicted from the results of both methods appeared to be similar. However, because samples collected in the future will be analyzed by Method 6020, only the results from PACE were included in this report to reduce data variation potentially associated with inter-laboratory and analytical method differences.

20 FOSSIL-FUELED POWER PLANTS↗

DOE OSTI2023

Improving Dark Energy Constraints Using Low-Redshift Large-Scale Structures

The primary goal of this project was to improve constraints on dark energy measurements by improving our ability to extract cosmological information from low redshift large-scale structures. PI Clowe's project's primary aim was to reduce the bias in measurements of the masses of clusters of galaxies to a level where the evolution of the cluster mass function can be used in the Vera Rubin Observatory's Legacy Survey of Space and Time Dark Energy Science Collaboration survey to improve the accuracy of the measurement of dark energy and other cosmological parameters. Co-PI Seo's project studied observational systematics affecting large-scale clustering of galaxies, which will be used to improve dark energy constraints from the Dark Energy Spectroscopic Instrument (DESI). The cluster lensing project employed a series of simulations and observations of clusters of galaxies to test numerous potential systematic errors in cluster mass measurements using weak gravitational lensing as the accuracy of current weak lensing measurements are more than order of magnitude worse than what is required to use clusters of galaxies for accurate determination of dark energy parameters. PI Clowe and group developed and analyzed simulations to test for, and correct biases introduced in, the weak lensing measurement process. Finally, PI Clowe and group developed a method of detecting clusters using galaxy overdensities and applied the method to the BLISS and DES surveys. The success of spectroscopic dark energy mission such as the extended Baryon Oscillation Spectroscopic Survey (eBOSS) and the Dark Energy Spectroscopic Instrument (DESI) will depend on a thorough understanding of various observational systematics in the target density fluctuations that would give rise to spurious, non-cosmological signals. PI Seo and group developed a deep learning, artificial neural network (ANN) technique that modeled and mitigated such effects, aimed at deriving more robust galaxy clustering signals not only for the baryon acoustic oscillation feature and redshift-space distortions but also for primordial non-Gaussianity constraint.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2015

Elution of uranium and transition metals from amidoxime-based polymer adsorbents for sequestering uranium from seawater

High-surface-area amidoxime and carboxylic acid grafted polymer adsorbents developed at Oak Ridge National Laboratory were tested for sequestering uranium in a flowing seawater flume system at the PNNL-Marine Sciences Laboratory. FTIR spectra indicate that a KOH conditioning process is necessary to remove the proton from the carboxylic acid and make the sorbent effective for sequestering uranium from seawater. The alkaline conditioning process also converts the amidoxime groups to carboxylate groups in the adsorbent. Both Na 2 CO 3 H 2 O 2 and hydrochloric acid elution methods can remove ~95% of the uranium sequestered by the adsorbent after 42 days of exposure in real seawater. The Na 2 CO 3 H 2 O 2 elution method is more selective for uranium than conventional acid elution. Iron and vanadium are the two major transition metals competing with uranium for adsorption to the amidoxime-based adsorbents in real seawater. Tiron (4,5-Dihydroxy-1,3-benzenedisulfonic acid disodium salt, 1 M) can remove iron from the adsorbent very effectively at pH around 7. The coordination between vanadium (V) and amidoxime is also discussed based on our 51V NMR data.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2017

SRR's 'Next Step' in the Lean Journey -Taking Lean to the Workforce - 17247

The Savannah River Site, a U.S. Department of Energy (DOE) facility, contracted Savannah River Remediation (SRR) to manage its liquid waste project, which is a unique, high hazard nuclear waste treatment and disposal facility consisting of 51, one million-gallon underground waste tanks, a solvent extraction processing unit, a vitrification facility for the highest radioactive waste, and a grout solidification and disposal facility for a decontaminated salt solution. Our Project mission is to treat the nuclear waste and close the associated storage and treatment facilities, of which, 8 tanks have been closed to date. At SRR, the Lean business management system has been adopted to address site inefficiencies, aging infrastructure concerns and budget constraints. The Lean philosophy took root decades ago in the manufacturing sector and started with the work of W. Edwards Deming and his contemporaries. In more recent years the process has matured in the Toyota Production System and migrated into fields as diverse as services industries, health-care, and now the DOE complex. The first step of the SRR Lean Journey was to formally identify areas of improvement and initiate Value Stream Analysis (VSAs) and Rapid Improvement Events (RIEs). SRR has achieved improvements in procedure implementation, work planning and control, project schedule compression, and engineering requirements. SRR is now phasing in the next phase of Lean through Managing for Daily Improvement (MDI), Visual Management and 5S (sort, set in order, shine, standardize, and sustain). MDI is a fundamental Lean principle in that we use our most valuable asset, our employees, to drive continuous improvement versus a smaller population through formal events. Part of MDI includes visual management where the workforce can go to a 'dashboard' to see and understand the company mission and status. 5S is a process where a work group improves performance in an area by addressing physical organization, efficiency, uniformity, standardization, and mechanisms to sustain improvements. 5S stands for: Sort, Set in Order, Shine, Standardize, and Sustain. This paper will focus on the 'Next Step' in SRR's Lean journey by address how SRR is implementing MDI and 5S to improve CONOPs, Project efficiencies, and worker engagement in day to day operations. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2026

Circularization of 23S rRNA but not 16S rRNA within archaeal ribosomes

Background Processing of archaeal 16S and 23S rRNAs is believed to involve excision of individual rRNAs from polycistronic precursors, circularization of excised rRNAs, and re-linearization before the incorporation into ribosomes. However, all the knowledge is derived from several isolated species, leaving open the possibility that different processes may occur in other archaeal groups. Results Here, we investigate rRNAs from diverse and mostly uncultivated archaea. Sequencing of total cellular RNA from eight phylum-level lineages indicates that archaeal circular 23S rRNA transcript abundances vastly exceed those of linear counterparts, and linear versions are often undetectable. As the majority of rRNAs derive from mature ribosomes, the data suggest that ribosomes contain circular 23S rRNAs. Thus, we directly sequence RNA extracted from isolated ribosomes of a model archaeon, Methanosarcina acetivorans, and confirm that the 23S rRNAs in the ribosomes are circular. Structural modeling places the 5′ and 3′ ends of the linear precursors of archaeal 23S rRNAs in close proximity to form a GNRA tetraloop (in which N is A, C, G, or U and R is A or G), consistent with their existence as circular molecules. We also confirm the existence of circular 16S rRNA intermediates in transcriptomes of most archaea, yet a circular form is not evident in some distinct archaeal groups, suggesting that certain archaea do not circularize 16S rRNA during processing. Conclusions Our findings uncover unexpected variations in the processing required to generate mature rRNAs and the conformation of functional molecules in archaeal ribosomes.

Archaea↗

DOE OSTI2013

Implementation of Remote 3-Dimensional Image Guided Radiation Therapy Quality Assurance for Radiation Therapy Oncology Group Clinical Trials

Purpose: To report the process and initial experience of remote credentialing of three-dimensional (3D) image guided radiation therapy (IGRT) as part of the quality assurance (QA) of submitted data for Radiation Therapy Oncology Group (RTOG) clinical trials; and to identify major issues resulting from this process and analyze the review results on patient positioning shifts. Methods and Materials: Image guided radiation therapy datasets including in-room positioning CT scans and daily shifts applied were submitted through the Image Guided Therapy QA Center from institutions for the IGRT credentialing process, as required by various RTOG trials. A centralized virtual environment is established at the RTOG Core Laboratory, containing analysis tools and database infrastructure for remote review by the Physics Principal Investigators of each protocol. The appropriateness of IGRT technique and volumetric image registration accuracy were evaluated. Registration accuracy was verified by repeat registration with a third-party registration software system. With the accumulated review results, registration differences between those obtained by the Physics Principal Investigators and from the institutions were analyzed for different imaging sites, shift directions, and imaging modalities. Results: The remote review process was successfully carried out for 87 3D cases (out of 137 total cases, including 2-dimensional and 3D) during 2010. Frequent errors in submitted IGRT data and challenges in the review of image registration for some special cases were identified. Workarounds for these issues were developed. The average differences of registration results between reviewers and institutions ranged between 2 mm and 3 mm. Large discrepancies in the superior-inferior direction were found for megavoltage CT cases, owing to low spatial resolution in this direction for most megavoltage CT cases. Conclusion: This first experience indicated that remote review for 3D IGRT as part of QA for RTOG clinical trials is feasible and effective. The magnitude of registration discrepancy between institution and reviewer was presented, and the major issues were investigated to further improve this remote evaluation process.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2011

Stress-induced shifting of the morphotropic phase boundary in sol-gel derived Pb(Zr{sub 0.5}Ti{sub 0.5})O{sub 3} thin films

Highlights: {yields} Differing from Pb(Zr{sub 0.5}Ti{sub 0.5})O{sub 3} bulk ceramic with a tetragonal phase, our results indicate that for PZT thin films with the same composition monoclinic phase coexisting with tetragonal phase can appear. {yields} Tensile stress is suggested to play a role in shifting the morphotropic phase boundary to titanium-rich region in PZT thin films. {yields} The deteriorated ferroelectric properties can be attributed mainly to the presence of thin non-ferroelectric layer and large tensile stress. -- Abstract: The structure evolution of Pb(Zr{sub 0.5}Ti{sub 0.5})O{sub 3} thin films with different thicknesses on the Pt(1 1 1)/Ti/SiO{sub 2}/Si substrates has been investigated using X-ray diffraction and Raman scattering. Differing from Pb(Zr{sub 0.5}Ti{sub 0.5})O{sub 3} bulk ceramic with a tetragonal phase, our results indicate that for PZT thin films with the same composition monoclinic phase with Cm space group coexisting with tetragonal phase can appear. It is suggested that tensile stress plays a role in shifting the morphotropic phase boundary to titanium-rich region in PZT thin films. The deteriorated ferroelectric properties of PZT thin films can be attributed mainly to the presence of thin non-ferroelectric layer and large tensile stress.

36 MATERIALS SCIENCE↗

DOE OSTI2018

Structural, morphological, optical and magnetic properties of Ag3(2+x)InxNb4-xO11+δ (0.25 ≤ x ≤ 1.0) nanoparticles synthesized by sol–gel method

Highlights: • Novel Ag{sub 3 (2+x)} In{sub x}Nb{sub 4-x}O{sub 11+δ} nanoparticles were synthesized by sol-gel method and studied their optical magnetic properties. • XRD studies confirm the single-phase monoclinic lattice structure with P2/m space group. • Morphology, purity and homogeneity of samples were confirmed by SEM images, EDX and X-ray mapping. • The absorption spectra and tauc plots confirms the semiconductor nature of the samples. • Magnetic studies reveals the ferromagnetic behavior of the samples at room temperature. - Abstract: Herein, we report the structure, morphology, optical and magnetic properties of novel Ag{sub 3 (2+x)} In{sub x}Nb{sub 4-x}O{sub 11+δ} (0.25 ≤ × ≤ 1.0; A1–A4) nanoparticles prepared by sol-gel technique. The samples were studied using X-ray diffraction, electron microscopy, diffuse reflectance spectroscopy, vibrating sample magnetometer, and electron spin resonance. X-ray diffraction studies confirm the formation of monoclinic lattice type with P2/m space group. Purity and homogeneity of the samples were confirmed by X-ray mapping. The semiconductor nature of the samples was identified by optical absorption spectra which indicate an inter-band transition from the oxygen 2p to niobium 4d electronic states. The magnetization plots reveal the room temperature ferromagnetic behavior of the samples.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2016

Glycosylation of inositol phosphorylceramide sphingolipids is required for normal growth and reproduction in Arabidopsis

Sphingolipids are a major component of plant plasma membranes and endomembranes, and mediate a diverse range of biological processes. Study of the highly glycosylated glycosyl inositol phosphorylceramide (GIPC) sphingolipids has been slow as a result of challenges associated with the extractability of GIPCs, and their functions in the plant remain poorly characterized. We recently discovered an Arabidopsis GIPC glucuronosyltransferase, INOSITOL PHOSPHORYLCERAMIDE GLUCURONOSYLTRANSFERASE 1 (IPUT1), which is the first enzyme in the GIPC glycosylation pathway. Plants homozygous for the iput1 loss-of-function mutation were unobtainable, and so the developmental effects of reduced GIPC glucuronosylation could not be analyzed in planta. Using a pollen-specific rescue construct, we have here isolated homozygous iput1 mutants. The iput1 mutants show severe dwarfism, compromised pollen tube guidance, and constitutive activation of salicyclic acid-mediated defense pathways. The mutants also possess reduced GIPCs, increased ceramides, and an increased incorporation of short-chain fatty acids and dihydroxylated bases into inositol phosphorylceramides and GIPCs. The assignment of a direct role for GIPC glycan head groups in the impaired processes in iput1 mutants is complicated by the vast compensatory changes in the sphingolipidome; however, our results reveal that the glycosylation steps of GIPC biosynthesis are important regulated components of sphingolipid metabolism. In conclusion, this study corroborates previously suggested roles for GIPC glycans in plant growth and defense, suggests important role s for them in reproduction and demonstrates that the entire sphingolipidome is sensitive to their status.

Arabidopsis thaliana↗

DOE OSTI2016

Synthesis of ZnSnO{sub 3} nanostructure by sol gel method

Zinc Stannate (ZST) with composition ZnSnO{sub 3} is known for high electron mobility, optical, piezoelectric and charge storage properties. ZST crystalizes in different lattice structures, which allows a wide range of tunablity. We demonstrate successful synthesis of ZnSnO{sub 3} nanomaterial by sol-gel method. ZnSnO{sub 3} nanomaterials were calcined and sintered at different temperatures. Powder X-ray diffraction confirmed the single phase of the nanomaterial with rhombohedral R-3 space group. The Rietveld refinement of diffraction pattern yielded lattice parameter values a=5.26Å, c=14.09Å. Raman spectroscopy revealed higher activity towards higher wavenumbers. Raman shift around 530cm{sup −1} was found to be highly structure dependent, most probably due to anharmonic atomic vibrations in ZnO{sub 6}/SnO{sub 6} octahedra around center of mass. Sharp Peak around 650cm{sup −1} is characteristic of ZnSnO{sub 3} molecule.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2016

Microstructural, optical and electrical properties of LaFe{sub 0.5}Cr{sub 0.5}O{sub 3} perovskite nanostructures

Perovskite nanocrystalline powder of LaFe{sub 0.5}Cr{sub 0.5}O{sub 3} was synthesized by sol-gel combustion route and characterized by x-ray diffractometer (XRD), scanning electron microscopy (SEM) equipped with EDS, UV-visible and LCR meter at room temperature Rietveld refinement of the XRD data confirms that the sample is in single phase-rhombohedral structure with space group R-3C. SEM micrograph shows clear nanostructure of the sample and EDS ensures the presence of all elements in good stoichiometric. The optical absorption indicates the maximum absorption at 315 nm and optical band gap of 2.94 eV was estimated using Tauc’s relation. Dielectric constant (ε’) and loss were found to decrease with increase in frequencies. The dielectric behavior was explained on the basis of Maxwell-Wagner’s two layer model.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2014

Electrical properties of samarium cobaltite nanoparticles synthesized using Sol–Gel autocombustion route

Highlights: • The structural evolution and its electrical properties of samarium cobaltite nanograins are discussed. • Optimization of SmCoO{sub 3} nanograins is achieved by post sintering as-prepared gel at 800 °C. • The impedance spectra indicate the semiconducting behavior SmCoO{sub 3} nanograins. - Abstract: Nanograins of SmCoO{sub 3} are prepared by citric acid assisted Sol–Gel autocombustion route. The characterizations of crystal structure, surface morphology and electrical properties of SmCoO{sub 3} powder are done using XRD, HRSEM, FTIR and BDS. The structural evolution of SmCoO{sub 3} upon increasing the annealing temperature is followed using XRD and FTIR analyses. The powder sample contains polycrystalline grains with average size equal to 35 nm and orthorhombic perovskite structure with Pbnm space group. The vibrational bands observed in FTIR spectrum at 545 cm{sup −1} and 439 cm{sup −1} correspond to Co-O stretching modes in cobaltite system. HRSEM images of the sample show the formation of hexagonal shaped grains of samarium cobaltite. The AC electrical conductivity of 4.914 × 10{sup −5} S cm{sup −1} at 295 K is measured for SmCoO{sub 3} nanoparticles. The impedance spectra bring out the semiconducting behavior of the material.

36 MATERIALS SCIENCE↗