Effect of five year storage on total phenolic content and antioxidant capacity of almond (Amygdalus communisL.) hull and shell from different genotypes.

PubMed

Moosavi Dolatabadi, Khadijeh Sadat; Dehghan, Gholamreza; Hosseini, Siavash; Jahanban Esfahlan, Ali

2015-01-01

Almond (Prunus amygdalus) hull and shell are agricultural by-products that are a source of phenolic compounds.The processing of almond produce shell and hull, accounts for more than 50% by dry weight of the almond fruits. Recently, more studies have focused on the influence of storage conditions and postharvest handling on the nutritional quality of fruits, especially the antioxidant phenolics. In this study, influence of long-term storage (five years) on the total phenolic and antioxidant capacity of almond hull and shell from different genotypes was evaluated. The fruits of subjected genotypes were collected and their hull and shell were separated. They were dried and reduced to fine powder. This powder stored at room temperature for five years. The total phenolic content (TPC) and bioactivities (antioxidant potential: DPPH and ABTS radical scavenging and reducing power) of extracts were evaluated using spectrophotometric methods. It was found that TPC content and bioactivity levels in the stored almond hull and shell were different, compared to the hulls and shells which were evaluated in 2007. S1-4 genotype had the highest TPC and reducing power in its hull and shell.Low correlation coefficient was observed between phenolic content and the DPPH radical scavenging percentage in hull and shell extract. For the first time, results of this investigation showed that storage can influence the antioxidant and antiradical potential of almond hull and shell.

Nanostructured core-shell electrode materials for electrochemical capacitors

NASA Astrophysics Data System (ADS)

Jiang, Long-bo; Yuan, Xing-zhong; Liang, Jie; Zhang, Jin; Wang, Hou; Zeng, Guang-ming

2016-11-01

Core-shell nanostructure represents a unique system for applications in electrochemical energy storage devices. Owing to the unique characteristics featuring high power delivery and long-term cycling stability, electrochemical capacitors (ECs) have emerged as one of the most attractive electrochemical storage systems since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review aims to summarize recent progress on core-shell nanostructures for advanced supercapacitor applications in view of their hierarchical architecture which not only create the desired hierarchical porous channels, but also possess higher electrical conductivity and better structural mechanical stability. The core-shell nanostructures include carbon/carbon, carbon/metal oxide, carbon/conducting polymer, metal oxide/metal oxide, metal oxide/conducting polymer, conducting polymer/conducting polymer, and even more complex ternary core-shell nanoparticles. The preparation strategies, electrochemical performances, and structural stabilities of core-shell materials for ECs are summarized. The relationship between core-shell nanostructure and electrochemical performance is discussed in detail. In addition, the challenges and new trends in core-shell nanomaterials development have also been proposed.

Maintaining high moisture content of macadamia nuts-in-shell during storage induces brown centres in raw kernels.

PubMed

Walton, David A; Randall, Bruce W; Le Lagadec, Marie D; Wallace, Helen M

2013-09-01

Kernel brown centres in macadamia are a defect causing internal discolouration of kernels. This study investigates the effect on the incidence of brown centres in raw kernel after maintaining high moisture content in macadamia nuts-in-shell stored at temperatures of 30°C, 35°C, 40°C and 45°C. Brown centres of raw kernel increased with nuts-in-shell storage time and temperature when high moisture content was maintained by sealing in polyethylene bags. Almost all kernels developed the defect when kept at high moisture content for 5 days at 45°C, and 44% developed brown centres after only 2 days of storage at high moisture content at 45°C. This contrasted with only 0.76% when stored for 2 days at 45°C but allowed to dry in open-mesh bags. At storage temperatures below 45°C, there were fewer brown centres, but there were still significant differences between those stored at high moisture content and those allowed to dry (P < 0.05). Maintenance of high moisture content during macadamia nuts-in-shell storage increases the incidence of brown centres in raw kernels and the defect increases with time and temperature. On-farm nuts-in-shell drying and storage practices should rapidly remove moisture to reduce losses. Ideally, nuts-in-shell should not be stored at high moisture content on-farm at temperatures over 30°C. © 2013 Society of Chemical Industry.

Nonvolatile memory with Co-SiO2 core-shell nanocrystals as charge storage nodes in floating gate

NASA Astrophysics Data System (ADS)

Liu, Hai; Ferrer, Domingo A.; Ferdousi, Fahmida; Banerjee, Sanjay K.

2009-11-01

In this letter, we reported nanocrystal floating gate memory with Co-SiO2 core-shell nanocrystal charge storage nodes. By using a water-in-oil microemulsion scheme, Co-SiO2 core-shell nanocrystals were synthesized and closely packed to achieve high density matrix in the floating gate without aggregation. The insulator shell also can help to increase the thermal stability of the nanocrystal metal core during the fabrication process to improve memory performance.

Large-scale thermal energy storage using sodium hydroxide /NaOH/

NASA Technical Reports Server (NTRS)

Turner, R. H.; Truscello, V. C.

1977-01-01

A technique employing NaOH phase change material for large-scale thermal energy storage to 900 F (482 C) is described; the concept consists of 12-foot diameter by 60-foot long cylindrical steel shell with closely spaced internal tubes similar to a shell and tube heat exchanger. The NaOH heat storage medium fills the space between the tubes and outer shell. To charge the system, superheated steam flowing through the tubes melts and raises the temperature of NaOH; for discharge, pressurized water flows through the same tube bundle. A technique for system design and cost estimation is shown. General technical and economic properties of the storage unit integrated into a solar power plant are discussed.

Substantial enhancement of energy storage capability in polymer nanocomposites by encapsulation of BaTiO3 NWs with variable shell thickness.

PubMed

Wang, Guanyao; Huang, Yanhui; Wang, Yuxin; Jiang, Pingkai; Huang, Xingyi

2017-08-09

Dielectric polymer nanocomposites have received keen interest due to their potential application in energy storage. Nevertheless, the large contrast in dielectric constant between the polymer and nanofillers usually results in a significant decrease of breakdown strength of the nanocomposites, which is unfavorable for enhancing energy storage capability. Herein, BaTiO 3 nanowires (NWs) encapsulated by TiO 2 shells of variable thickness were utilized to fabricate dielectric polymer nanocomposites. Compared with nanocomposites with bare BaTiO 3 NWs, significantly enhanced energy storage capability was achieved for nanocomposites with TiO 2 encapsulated BaTiO 3 NWs. For instance, an ultrahigh energy density of 9.53 J cm -3 at 440 MV m -1 could be obtained for nanocomposites comprising core-shell structured nanowires, much higher than that of nanocomposites with 5 wt% raw ones (5.60 J cm -3 at 360 MV m -1 ). The discharged energy density of the proposed nanocomposites with 5 wt% mTiO 2 @BaTiO 3 -1 NWs at 440 MV m -1 seems to rival or exceed those of some previously reported nanocomposites (mostly comprising core-shell structured nanofillers). More notably, this study revealed that the energy storage capability of the nanocomposites can be tailored by the TiO 2 shell thickness. Finite element simulations were employed to analyze the electric field distribution in the nanocomposites. The enhanced energy storage capability should be mainly attributed to the smoother gradient of dielectric constant between the nanofillers and polymer matrix, which alleviated the electric field concentration and leakage current in the polymer matrix. The methods and results herein offer a feasible approach to construct high-energy-density polymer nanocomposites with core-shell structured nanowires.

76 FR 81513 - Guidance for Industry: Prevention of Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-28

...] Guidance for Industry: Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and... ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation.'' The document provides guidance to egg producers on how to comply with certain provisions contained in FDA's...

A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiOx core-shell nanoparticles

NASA Astrophysics Data System (ADS)

Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M.; Lu, Ming-Chang; Chueh, Yu-Lun

2014-04-01

We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiOx core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiOx core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiOx core-shell NPs during cyclic heating processes. The latent heat of ~29 J g-1 for Sn/SiOx core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g-1 K-1 for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiOx core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants. Electronic supplementary information (ESI) available: Detailed experimental results are included for the following: SEM images of the HITEC molten salt with and without a mixture of Sn/SiOx core-shell NPs; statistical diameter distribution of pure Sn and Sn/SiOx core-shell NPs; the HAADF image and EDS linescan profile of a Sn/SiOx core-shell NP; XRD analysis for Sn NPs annealing at different heating temperatures; the XRD spectra of Sn/SiOx core-shell NPs before and after RTA for the shell protection test. See DOI: 10.1039/c3nr06810b

Hydrogel Encapsulation Facilitates Rapid-Cooling Cryopreservation of Stem Cell-Laden Core-Shell Microcapsules as Cell-Biomaterial Constructs.

PubMed

Zhao, Gang; Liu, Xiaoli; Zhu, Kaixuan; He, Xiaoming

2017-12-01

Core-shell structured stem cell microencapsulation in hydrogel has wide applications in tissue engineering, regenerative medicine, and cell-based therapies because it offers an ideal immunoisolative microenvironment for cell delivery and 3D culture. Long-term storage of such microcapsules as cell-biomaterial constructs by cryopreservation is an enabling technology for their wide distribution and ready availability for clinical transplantation. However, most of the existing studies focus on cryopreservation of single cells or cells in microcapsules without a core-shell structure (i.e., hydrogel beads). The goal of this study is to achieve cryopreservation of stem cells encapsulated in core-shell microcapsules as cell-biomaterial constructs or biocomposites. To this end, a capillary microfluidics-based core-shell alginate hydrogel encapsulation technology is developed to produce porcine adipose-derived stem cell-laden microcapsules for vitreous cryopreservation with very low concentration (2 mol L -1 ) of cell membrane penetrating cryoprotective agents (CPAs) by suppressing ice formation. This may provide a low-CPA and cost-effective approach for vitreous cryopreservation of "ready-to-use" stem cell-biomaterial constructs, facilitating their off-the-shelf availability and widespread applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

78 FR 44483 - Draft Guidance for Industry: Questions and Answers Regarding the Final Rule, Prevention of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-24

... Regarding the Final Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and... Rule, Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation (Layers with Outdoor Access)'' (the draft guidance). The document provides guidance to egg producers on...

Hen genetic strain and extended cold storage influence on physical egg quality from cage-free aviary housing system.

PubMed

Jones, D R; Karcher, D M; Regmi, P; Robison, C O; Gast, R K

2018-04-02

In the United States, there is an increase in need for cage-free eggs in retail and food manufacturing sectors. Understanding the impact of cage-free systems and the corresponding management on egg quality is pertinent as the U.S. industry adapts existing housing and builds new cage-free housing structures. A study was conducted comparing 2 brown shell and 2 white shell hen strains housed in a cage-free aviary system. Each set of eggs were placed in cold storage and assessed at 0, 2, 4, 8, and 12 wk. Eggs were collected at 21, 31, 42, and 60 wk of hen age. A full profile of physical quality measurements was conducted on up to 18 intact eggs for each hen strain/egg storage/hen age combination. Egg weight increased approximately 10 g for brown shell and 14 g for white shell eggs as hens aged. Many of the properties monitored were significantly impacted by all 3 main effects (hen strain, egg storage, and hen age) resulting in 3-way interactions. A brown and a white shell strain had stronger shells (44 N; P < 0.0001) than the remaining brown and white shell strains (42 N and 39 N, respectively). The current study also determined volume of shell, total length, maximum width, and percent length at maximum width to more accurately indicate egg shape than shape index. One brown shell strain produced eggs with the most consistent shape characteristics over the hen ages monitored. White shell eggs from the cage-free aviary housing produced the highest whole-egg total solids between 31 to 60 wk of hen age, whereas brown shell eggs resulted in the most consistent level of whole-egg total solids (22-23.5%). The brown and white shell strains in the current study produce cage-free aviary eggs with distinctive physical quality attributes. The outcomes from this study can be utilized by the U.S. egg industry in planning management strategies and market placement of cage-free eggs.

Enhanced charge storage capability of Ge/GeO(2) core/shell nanostructure.

PubMed

Yuan, C L; Lee, P S

2008-09-03

A Ge/GeO(2) core/shell nanostructure embedded in an Al(2)O(3) gate dielectrics matrix was produced. A larger memory window with good data retention was observed in the fabricated metal-insulator-semiconductor (MIS) capacitor for Ge/GeO(2) core/shell nanoparticles compared to Ge nanoparticles only, which is due to the high percentage of defects located on the surface and grain boundaries of the GeO(2) shell. We believe that the findings presented here provide physical insight and offer useful guidelines to controllably modify the charge storage properties of indirect semiconductors through defect engineering.

Alternative Storage Environments for Shelled Peanuts.

USDA-ARS?s Scientific Manuscript database

Alternative Storage Environments for Shelled Peanuts. C. L. BUTTS1, K. HORM2, S. POWELL3, B. ANTHONY2, J. BENNETT2, D. COWART3, and M.C. LAMB1. 1USDA, ARS, National Peanut Research Laboratory, Dawson, GA, 2Mars Chocolate NA, Elizabethtown, PA,3 Birdsong Peanuts, Blakely, GA Small chamber studies w...

75 FR 18849 - Small Entity Compliance Guide: Prevention of Salmonella Enteritidis in Shell Eggs During...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-13

...] Small Entity Compliance Guide: Prevention of Salmonella Enteritidis in Shell Eggs During Production... ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation--Small... requiring shell egg producers to implement measures to prevent Salmonella Enteritidis (SE) from...

Multiple Interfacial Fe3O4@BaTiO3/P(VDF-HFP) Core-Shell-Matrix Films with Internal Barrier Layer Capacitor (IBLC) Effects and High Energy Storage Density.

PubMed

Zhou, Ling; Fu, Qiuyun; Xue, Fei; Tang, Xiahui; Zhou, Dongxiang; Tian, Yahui; Wang, Geng; Wang, Chaohong; Gou, Haibo; Xu, Lei

2017-11-22

Flexible nanocomposites composed of high dielectric constant fillers and polymer matrix have shown great potential for electrostatic capacitors and energy storage applications. To obtain the composited material with high dielectric constant and high breakdown strength, multi-interfacial composited particles, which composed of conductive cores and insulating shells and possessed the internal barrier layer capacitor (IBLC) effect, were adopted as fillers. Thus, Fe 3 O 4 @BaTiO 3 core-shell particles were prepared and loaded into the poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) polymer matrix. As the mass fraction of core-shell fillers increased from 2.5 wt % to 30 wt %, the dielectric constant of the films increased, while the loss tangent remained at a low level (<0.05 at 1 kHz). Both high electric displacement and high electric breakdown strength were achieved in the films with 10 wt % core-shell fillers loaded. The maximum energy storage density of 7.018 J/cm 3 was measured at 2350 kV/cm, which shows significant enhancement than those of the pure P(VDF-HFP) films and analogous composited films with converse insulating-conductive core-shell fillers. A Maxwell-Wagner capacitor model was also adopted to interpret the efficiency of IBLC effects on the suppressed loss tangent and the superior breakdown strength. This work explored an effective approach to prepare dielectric nanocomposites for energy storage applications experimentally and theoretically.

21 CFR 118.11 - Registration requirements for shell egg producers covered by the requirements of this part.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Registration requirements for shell egg producers..., STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.11 Registration requirements for shell egg producers covered by the requirements of this part. (a) Shell egg producers covered under § 118.1(a) of this part...

21 CFR 118.11 - Registration requirements for shell egg producers covered by the requirements of this part.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Registration requirements for shell egg producers..., STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.11 Registration requirements for shell egg producers covered by the requirements of this part. (a) Shell egg producers covered under § 118.1(a) are required to...

STORAGE RING CROSS SECTION MEASUREMENTS FOR ELECTRON IMPACT SINGLE AND DOUBLE IONIZATION OF Fe{sup 13+} AND SINGLE IONIZATION OF Fe{sup 16+} AND Fe{sup 17+}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hahn, M.; Novotny, O.; Savin, D. W.

2013-04-10

We report measurements of electron impact ionization for Fe{sup 13+}, Fe{sup 16+}, and Fe{sup 17+} over collision energies from below threshold to above 3000 eV. The ions were recirculated using an ion storage ring. Data were collected after a sufficiently long time that essentially all the ions had relaxed radiatively to their ground state. For single ionization of Fe{sup 13+}, we find that previous single pass experiments are more than 40% larger than our results. Compared to our work, the theoretical cross section recommended by Arnaud and Raymond is more than 30% larger, while that of Dere is about 20%more » greater. Much of the discrepancy with Dere is due to the theory overestimating the contribution of excitation-autoionization via n = 2 excitations. Double ionization of Fe{sup 13+} is dominated by direct ionization of an inner shell electron accompanied by autoionization of a second electron. Our results for single ionization of Fe{sup 16+} and Fe{sup 17+} agree with theoretical calculations to within the experimental uncertainties.« less

Prevention of Salmonella enteritidis in shell eggs during production, storage, and transportation. Final rule.

PubMed

2009-07-09

The Food and Drug Administration (FDA) is issuing a final rule that requires shell egg producers to implement measures to prevent Salmonella Enteritidis (SE) from contaminating eggs on the farm and from further growth during storage and transportation, and requires these producers to maintain records concerning their compliance with the rule and to register with FDA. FDA is taking this action because SE is among the leading bacterial causes of foodborne illness in the United States, and shell eggs are a primary source of human SE infections. The final rule will reduce SE-associated illnesses and deaths by reducing the risk that shell eggs are contaminated with SE.

Synergetic Effect of Yolk-Shell Structure and Uniform Mixing of SnS-MoS₂ Nanocrystals for Improved Na-Ion Storage Capabilities.

PubMed

Choi, Seung Ho; Kang, Yun Chan

2015-11-11

Mixed metal sulfide composite microspheres with a yolk-shell structure for sodium-ion batteries are studied. Tin-molybdenum oxide yolk-shell microspheres prepared by a one-pot spray pyrolysis process transform into yolk-shell SnS-MoS2 composite microspheres. The discharge capacities of the yolk-shell and dense-structured SnS-MoS2 composite microspheres for the 100th cycle are 396 and 207 mA h g(-1), and their capacity retentions measured from the second cycle are 89 and 47%, respectively. The yolk-shell SnS-MoS2 composite microspheres with high structural stability during repeated sodium insertion and desertion processes have low charge-transfer resistance even after long-term cycling. The synergetic effect of the yolk-shell structure and uniform mixing of the SnS and MoS2 nanocrystals result in the excellent sodium-ion storage properties of the yolk-shell SnS-MoS2 composite microspheres by improving their structural stability during cycling.

Engineering report for simulated riser installation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brevick, C.H., Westinghouse Hanford

1996-05-09

The simulated riser installation field tests demonstrated that new access ports (risers) can be installed safely, quickly, and economically in the concrete domes of existing underground single- shell waste storage tanks by utilizing proven rotary drilling equipment and vacuum excavation techniques. The new riser installation will seal against water intrusion, provide as table riser anchored to the tank dome, and be installed in accordance with ALARA principles. The information contained in the report will apply to actual riser installation activity in the future.

Initial retrieval sequence and blending strategy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pemwell, D.L.; Grenard, C.E.

1996-09-01

This report documents the initial retrieval sequence and the methodology used to select it. Waste retrieval, storage, pretreatment and vitrification were modeled for candidate single-shell tank retrieval sequences. Performance of the sequences was measured by a set of metrics (for example,high-level waste glass volume, relative risk and schedule).Computer models were used to evaluate estimated glass volumes,process rates, retrieval dates, and blending strategy effects.The models were based on estimates of component inventories and concentrations, sludge wash factors and timing, retrieval annex limitations, etc.

Safety evaluation for packaging transportation of equipment for tank 241-C-106 waste sluicing system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calmus, D.B.

1994-08-25

A Waste Sluicing System (WSS) is scheduled for installation in nd waste storage tank 241-C-106 (106-C). The WSS will transfer high rating sludge from single shell tank 106-C to double shell waste tank 241-AY-102 (102-AY). Prior to installation of the WSS, a heel pump and a transfer pump will be removed from tank 106-C and an agitator pump will be removed from tank 102-AY. Special flexible receivers will be used to contain the pumps during removal from the tanks. After equipment removal, the flexible receivers will be placed in separate containers (packagings). The packaging and contents (packages) will be transferredmore » from the Tank Farms to the Central Waste Complex (CWC) for interim storage and then to T Plant for evaluation and processing for final disposition. Two sizes of packagings will be provided for transferring the equipment from the Tank Farms to the interim storage facility. The packagings will be designated as the WSSP-1 and WSSP-2 packagings throughout the remainder of this Safety Evaluation for Packaging (SEP). The WSSP-1 packagings will transport the heel and transfer pumps from 106-C and the WSSP-2 packaging will transport the agitator pump from 102-AY. The WSSP-1 and WSSP-2 packagings are similar except for the length.« less

Contra-rotating homopolar motor-generator for energy storage and return

DOEpatents

Kustom, Robert L.; Wehrle, Robert B.

1978-01-01

An apparatus for receiving electrical energy in amounts of the order of hundreds of megajoules, converting the electrical energy to mechanical energy for storage, and delivering the stored energy as electrical energy in times of the order of a second comprises a sequence of stacked electrically conducting cylindrical shells having a common axis. The conducting shells are free to rotate and are separated by stationary insulating cylindrical shells. Adjacent conducting shells are connected electrically by brushes at the edges and a radial magnetic field is caused to pass through the conductors. The apparatus permits the reversal in a plasma heating coil of electric currents of amplitudes up to 100,000 amperes in a time of the order of a second.

A solar-thermal energy harvesting scheme: enhanced heat capacity of molten HITEC salt mixed with Sn/SiO(x) core-shell nanoparticles.

PubMed

Lai, Chih-Chung; Chang, Wen-Chih; Hu, Wen-Liang; Wang, Zhiming M; Lu, Ming-Chang; Chueh, Yu-Lun

2014-05-07

We demonstrated enhanced solar-thermal storage by releasing the latent heat of Sn/SiO(x) core-shell nanoparticles (NPs) embedded in a eutectic salt. The microstructures and chemical compositions of Sn/SiO(x) core-shell NPs were characterized. In situ heating XRD provides dynamic crystalline information about the Sn/SiO(x) core-shell NPs during cyclic heating processes. The latent heat of ∼29 J g(-1) for Sn/SiO(x) core-shell NPs was measured, and 30% enhanced heat capacity was achieved from 1.57 to 2.03 J g(-1) K(-1) for the HITEC solar salt without and with, respectively, a mixture of 5% Sn/SiO(x) core-shell NPs. In addition, an endurance cycle test was performed to prove a stable operation in practical applications. The approach provides a method to enhance energy storage in solar-thermal power plants.

Impact of pecan nut shell aqueous extract on the oxidative properties of margarines during storage.

PubMed

Engler Ribeiro, Paula Cristina; de Britto Policarpi, Priscila; Dal Bo, Andrea; Barbetta, Pedro Alberto; Block, Jane Mara

2017-07-01

The oxidative properties of margarines supplemented with pecan nut shell extract, rosemary extract and butylated hydroxytoluene (BHT) were investigated. The extracts of pecan nut shell and rosemary showed a high content of total phenolics and condensed tannins (93 and 102.9 mg GAE g -1 and 46 and 38.9 mg CE g -1 respectively) as well as a high antioxidant activity (1257 and 2306 µmol TEAC g -1 and 293 and 856 mg TEAC g -1 by ABTS and DPPH methods respectively). Gallic acid, chlorogenic acid, p-hydroxybenzoic acid, epicatechin and epicatechin gallate were identified in the pecan nut shell extract. Peroxide and p-anisidine values of 3.75-4.43 meq kg -1 and 1.22-2.73 respectively, Totox values of 9.88-10.8 and specific extinction values of 4.38-4.59 and 0.92-0.94 at 232 and 268 nm respectively were observed after 8 months of storage in the studied samples. Margarines supplemented with pecan nut shell extract, rosemary extract or BHT during prolonged storage were found to be of equal quality within the degree of confidence limits. The extract of pecan nut shell may be considered as a natural product replacement for the synthetic antioxidant BHT. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Combination of super chilling and high carbon dioxide concentration techniques most effectively to preserve freshness of shell eggs during long-term storage.

PubMed

Yanagisawa, T; Ariizumi, M; Shigematsu, Y; Kobayashi, H; Hasegawa, M; Watanabe, K

2010-01-01

This study was made to examine the combined effects of stored temperature and carbon dioxide atmosphere on shell egg quality. The shell eggs were packed into polyethylene terephthalate/polyethylene (PET/PE) pouches and stored at 0 degrees C (super chilling), 10 degrees C, and 20 degrees C, respectively for 90 d. The atmospheric carbon dioxide concentration was controlled to obtain the 3 concentration levels of high (about 2.0%), medium (about 0.5%), and low (below 0.01%). Changes in Haugh unit (HU) values, weakening of vitelline membranes, and generation of volatiles were analyzed to evaluate the freshness of shell eggs. Results showed that, compared with the other combinations, the technique of super chilling and high carbon dioxide concentration enabled shell eggs to be most effectively stored for 90 d, based on estimations of the statistical significances of differences in HU values, and on maintaining the initial HU values during storage. In addition, the storage of shell eggs using this combination technique was found to significantly prevent the weakening of the vitelline membrane based on the estimations of numbers of eggs without vitelline membrane breakage when eggs broke, and significantly lowered the incidence of hexanal in the yolk from exposure to the gas chromatographic-mass spectrometric analyses of volatiles. Thus, these results confirmed that the combination of super chilling and high carbon dioxide concentration was the most effective technique for preserving shell eggs during a long term of 90 d compared with other combination techniques.

Magnetic spherical cores partly coated with periodic mesoporous organosilica single crystals.

PubMed

Li, Jing; Wei, Yong; Li, Wei; Deng, Yonghui; Zhao, Dongyuan

2012-03-07

Core-shell structured materials are of special significance in various applications. Until now, most reported core-shell structures have polycrystalline or amorphous coatings as their shell layers, with popular morphologies of microspheres or quasi-spheres. However, the single crystals, either mesoscale or atomic ones, are still rarely reported as shell layers. If single crystals can be coated on core materials, it would result in a range of new type core-shell structures with various morphologies, and probably more potential applications. In this work, we demonstrate that periodic mesoporous organosilica (PMO) single crystals can partly grow on magnetic microspheres to form incomplete Fe(3)O(4)@nSiO(2)@PMO core-shell materials in aqueous solution, which indeed is the first illustration that mesoporous single-crystal materials can be used as shell layers for preparation of core-shell materials. The achieved materials have advantages of high specific surface areas, good magnetic responses, embedded functional groups and cubic mesopore channels, which might provide them with various application conveniences. We suppose the partial growth is largely decided by the competition between growing tendency of single crystals and the resistances to this tendency. In principle, other single crystals, including a range of atomic single crystals, such as zeolites, are able to be developed into such core-shell structures.

Highly sensitive and stable Ag@SiO2 nanocubes for label-free SERS-photoluminescence detection of biomolecules

NASA Astrophysics Data System (ADS)

Nguyen, Minh-Kha; Su, Wei-Nien; Chen, Ching-Hsiang; Rick, John; Hwang, Bing-Joe

2017-03-01

Surface-enhanced Raman scattering (SERS) and fluorescence microscopy are a widely used biological and chemical characterization techniques. However, the peak overlapping in multiplexed experiments and rapid photobleaching of fluorescent organic dyes is still the limitations. When compared to Ag nanocubes (NCs), higher SERS sensitivities can be obtained with thin shelled silica Ag@SiO2 NCs, in contrast metal-enhanced photoluminescence (MEPL) is only found with NCs that have thicker silica shells. A 'dual functionality' represented by the simultaneous strengthening of SERS and MEPL signals can be achieved by mixing Ag@SiO2 NCs, with a silica shell thickness of 1.5 nm and 4.4 nm. This approach allows both the Ag@SiO2 NCs SERS and MEPL sensitivities to be maintained at 90% after 12 weeks of storage. Based on the distinguished detection of creatinine and flavin adenine dinucleotide in the mixture, the integration of SERS and MEPL together on a stable single plasmonic nanoparticle platform offers an opportunity to enhance both biomarker detection sensitivity and specificity.

Epitaxial Growth of Lattice-Mismatched Core-Shell TiO2 @MoS2 for Enhanced Lithium-Ion Storage.

PubMed

Dai, Rui; Zhang, Anqi; Pan, Zhichang; Al-Enizi, Abdullah M; Elzatahry, Ahmed A; Hu, Linfeng; Zheng, Gengfeng

2016-05-01

Core-shell structured nanohybrids are currently of significant interest due to their synergetic properties and enhanced performances. However, the restriction of lattice mismatch remains a severe obstacle for heterogrowth of various core-shells with two distinct crystal structures. Herein, a controlled synthesis of lattice-mismatched core-shell TiO2 @MoS2 nano-onion heterostructures is successfully developed, using unilamellar Ti0.87 O2 nanosheets as the starting material and the subsequent epitaxial growth of MoS2 on TiO2 . The formation of these core-shell nano-onions is attributed to an amorphous layer-induced heterogrowth mechanism. The number of MoS2 layers can be well tuned from few to over ten layers, enabling layer-dependent synergistic effects. The core-shell TiO2 @MoS2 nano-onion heterostructures exhibit significantly enhanced energy storage performance as lithium-ion battery anodes. The approach has also been extended to other lattice-mismatched systems such as TiO2 @MoSe2 , thus suggesting a new strategy for the growth of well-designed lattice-mismatched core-shell structures. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low temperature storage container for transporting perishables to space station

NASA Technical Reports Server (NTRS)

Owen, James W. (Inventor); Dean, William G. (Inventor)

1989-01-01

Two storage containers are disclosed within which food or biological samples may be stored for transfer in a module by the space shuttle to a space station while maintaining the food or samples at very low temperatures. The container is formed in two parts, each part having an inner shell and an outer shell disposed about the inner shell. The space between the shells is filled with a continuous wrap multi-layer insulation and a getter material. The two parts of the container have interlocking members and when connected together are sealed for preventing leakage from the space between the shells. After the two parts are filled with frozen food or samples they are connected together and a vacuum is drawn in the space between the shells and the container is stored in the module. For the extremely low temperature requirements of biological samples, an internal liner having a phase change material charged by a refrigerant coil is disposed in the space between the shells, and the container is formed from glass fiber material including honeycomb structural elements. All surfaces of the glass fiber which face the vacuum space are lined with a metal foil.

Staged depressurization system

DOEpatents

Schulz, T.L.

1993-11-02

A nuclear reactor having a reactor vessel disposed in a containment shell is depressurized in stages using depressurizer valves coupled in fluid communication with the coolant circuit. At least one sparger submerged in the in-containment refueling water storage tank which can be drained into the containment sump communicates between one or more of the valves and an inside of the containment shell. The depressurizer valves are opened in stages, preferably at progressively lower coolant levels and for opening progressively larger flowpaths to effect depressurization through a number of the valves in parallel. The valves can be associated with a pressurizer tank in the containment shell, coupled to a coolant outlet of the reactor. At least one depressurization valve stage openable at a lowest pressure is coupled directly between the coolant circuit and the containment shell. The reactor is disposed in the open sump in the containment shell, and a further valve couples the open sump to a conduit coupling the refueling water storage tank to the coolant circuit for adding water to the coolant circuit, whereby water in the containment shell can be added to the reactor from the open sump. 4 figures.

Staged depressurization system

DOEpatents

Schulz, Terry L.

1993-01-01

A nuclear reactor having a reactor vessel disposed in a containment shell is depressurized in stages using depressurizer valves coupled in fluid communication with the coolant circuit. At least one sparger submerged in the in-containment refueling water storage tank which can be drained into the containment sump communicates between one or more of the valves and an inside of the containment shell. The depressurizer valves are opened in stages, preferably at progressively lower coolant levels and for opening progressively larger flowpaths to effect depressurization through a number of the valves in parallel. The valves can be associated with a pressurizer tank in the containment shell, coupled to a coolant outlet of the reactor. At least one depressurization valve stage openable at a lowest pressure is coupled directly between the coolant circuit and the containment shell. The reactor is disposed in the open sump in the containment shell, and a further valve couples the open sump to a conduit coupling the refueling water storage tank to the coolant circuit for adding water to the coolant circuit, whereby water in the containment shell can be added to the reactor from the open sump.

Rational design and synthesis of yolk-shell ZnGa2O4@C nanostructure with enhanced lithium storage properties

NASA Astrophysics Data System (ADS)

Han, Nao; Xia, Yuguo; Han, Yanyang; Jiao, Xiuling; Chen, Dairong

2018-03-01

The ability to create hybrid nanostructure with synergistic effect and confined morphology to achieve high performance and long-term stability is high desirable in lithium ion batteries. Although transition metal oxides as anode material reveal high theoretical capacities, the significant volume changes during repeated lithium insertion and extraction cause pulverization of electrode materials, resulting in rapid fade in capacity. Herein, yolk-shell nanostructure of ZnGa2O4 encapsulated by amorphous carbon is rationally designed and synthesized through two-step surface coating followed by thermal treatment and etching process. It is noteworthy that ZnGa2O4@C with yolk-shell structure is superior to pristine ZnGa2O4 and ZnGa2O4@C with core-shell structure in term of lithium storage. The stable reversible capacity of yolk-shell ZnGa2O4@C can be retained at 657.2 mAh g-1 at current density of 1 A g-1 after completion of 300 cycles, which also reveals superior rate performance. The appropriate carbon shell and void space involved in the yolk-shell structure are considered to be the crucial factor in accommodating volume expansion as well as preserving the structural integrity of yolk-shell ZnGa2O4@C.

Effect of storage of shelled Moringa oleifera seeds from reaping time on turbidity removal.

PubMed

Golestanbagh, M; Ahamad, I S; Idris, A; Yunus, R

2011-09-01

Moringa oleifera is an indigenous plant to Malaysia whose seeds are used for water purification. Many studies on Moringa oleifera have shown that it is highly effective as a natural coagulant for turbidity removal. In this study, two different methods for extraction of Moringa's active ingredient were investigated. Results of sodium chloride (NaCl) and distilled water extraction of Moringa oleifera seeds showed that salt solution extraction was more efficient than distilled water in extracting Moringa's active coagulant ingredient. The optimum dosage of shelled Moringa oleifera seeds extracted by the NaCl solution was comparable with that of the conventional chemical coagulant alum. Moreover, the turbidity removal efficiency was investigated for shelled Moringa oleifera seeds before drying in the oven under different storage conditions (i.e. open and closed containers at room temperature, 27 °C) and durations (fresh, and storage for 2, 4, 6 and 8 weeks from the time the seeds were picked from the trees). Our results indicate that there are no significant differences in coagulation efficiencies and, accordingly, turbidity removals between the examined storage conditions and periods.

Stress relaxation in pre-stressed aluminum core–shell particles: X-ray diffraction study, modeling, and improved reactivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levitas, Valery I.; McCollum, Jena; Pantoya, Michelle L.

Stress relaxation in aluminum micron-scale particles covered by alumina shell after pre-stressing by thermal treatment and storage was measured using X-ray diffraction with synchrotron radiation. Pre-stressing was produced by annealing Al particles at 573K followed by fast cooling. While averaged dilatational strain in Al core was negligible for untreated particles, it was measured at 4.40×10 -5 and 2.85×10 -5 after 2 and 48 days of storage. Consistently, such a treatment leads to increase in flame propagation speed for Al+CuO mixture by 37% and 25%, respectively. Analytical model for creep in alumna shell and stress relaxation in Al core-alumina shellmore » structure is developed and activation energy and pre-exponential multiplier are estimated. The effect of storage temperature and annealing temperature on the kinetics of stress relaxation was evaluated theoretically. These results provide estimates for optimizing Al reactivity with the holding time at annealing temperature and allowable time for storage of Al particles for various environmental temperatures.« less

Stress relaxation in pre-stressed aluminum core–shell particles: X-ray diffraction study, modeling, and improved reactivity

DOE PAGES

Levitas, Valery I.; McCollum, Jena; Pantoya, Michelle L.; ...

2016-05-30

Stress relaxation in aluminum micron-scale particles covered by alumina shell after pre-stressing by thermal treatment and storage was measured using X-ray diffraction with synchrotron radiation. Pre-stressing was produced by annealing Al particles at 573K followed by fast cooling. While averaged dilatational strain in Al core was negligible for untreated particles, it was measured at 4.40×10 -5 and 2.85×10 -5 after 2 and 48 days of storage. Consistently, such a treatment leads to increase in flame propagation speed for Al+CuO mixture by 37% and 25%, respectively. Analytical model for creep in alumna shell and stress relaxation in Al core-alumina shellmore » structure is developed and activation energy and pre-exponential multiplier are estimated. The effect of storage temperature and annealing temperature on the kinetics of stress relaxation was evaluated theoretically. These results provide estimates for optimizing Al reactivity with the holding time at annealing temperature and allowable time for storage of Al particles for various environmental temperatures.« less

Effect of Chitin Isolated from Crustaceans and Cephalopods on Denaturation of Fish Myofibrillar Protein and the State of Water during Frozen Storage

NASA Astrophysics Data System (ADS)

Arredondo Romero, Eduardo; Nakamura, Yukio; Yamashita, Yasumitsu; Ichikawa, Hisashi; Goto, Shingi; Osatomi, Kiyoshi; Nozaki, Yukinori

From the point of view of utilization of shells as a waste product of fishery industry, the cryoprotective effect of chitin made from shell of crustaceans (Japanese fan lobster and Japanese swimming crab) and cartilage of cephalopods (spear squid) are studied. Chitin from the shells and cartilage were added to lizard fish myofibrils, and the changes of unfrozen water in myofibrils and ATPase activity of myofibrillar protein were observed during frozen storage at -250°C for 120days. The amount of unfrozen water were increased by addition of three kinds of chitin, and decreased moderately during forzen storage. Whereas, in the chitin free sample, the amount of unfrozen water were decreased rapidly during frozen storage. Changes of ATPase activity of samples showed similar tendency to that of the amount of unfrozen water. The present moderate cryoprotective effect of chitin and data of unfrozen water and ATPase activity of myofibrillar protein suggest the importance of the amount of unfrozen water in frozen matrix.

Slurry growth, gas retention, and flammable gas generation by Hanford radioactive waste tanks: Synthetic waste studies, FY 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bryan, S.A.; Pederson, L.R.; Ryan, J.L.

1992-08-01

Of 177 high-level waste storage tanks on the Hanford Site, 23 have been placed on a safety watch list because they are suspected of producing flammable gases in flammable or explosive concentrate. One tankin particular, Tank 241-SY-101 (Tank 101-SY), has exhibited slow increases in waste volume followed by a rapid decrease accompanied by venting of large quantities of gases. The purpose of this study is to help determine the processes by which flammable gases are produced, retained, and eventually released from Tank 101-SY. Waste composition data for single- and double-shell waste tanks on the flammable gas watch listare critically reviewed.more » The results of laboratory studies using synthetic double-shell wastes are summarized, including physical and chemical properties of crusts that are formed, the stoichiometry and rate ofgas generation, and mechanisms responsible for formation of a floating crust.« less

In-situ observation for growth of hierarchical metal-organic frameworks and their self-sequestering mechanism for gas storage

NASA Astrophysics Data System (ADS)

Hyo Park, Jung; Min Choi, Kyung; Joon Jeon, Hyung; Jung Choi, Yoon; Ku Kang, Jeung

2015-07-01

Although structures with the single functional constructions and micropores were demonstrated to capture many different molecules such as carbon dioxide, methane, and hydrogen with high capacities at low temperatures, their feeble interactions still limit practical applications at room temperature. Herein, we report in-situ growth observation of hierarchical pores in pomegranate metal-organic frameworks (pmg-MOFs) and their self-sequestering storage mechanism, not observed for pristine MOFs. Direct observation of hierarchical pores inside the pmg-MOF was evident by in-situ growth X-ray measurements while self-sequestering storage mechanism was revealed by in-situ gas sorption X-ray analysis and molecular dynamics simulations. The results show that meso/macropores are created at the early stage of crystal growth and then enclosed by micropore crystalline shells, where hierarchical pores are networking under self-sequestering mechanism to give enhanced gas storage. This pmg-MOF gives higher CO2 (39%) and CH4 (14%) storage capacity than pristine MOF at room temperature, in addition to fast kinetics with robust capacity retention during gas sorption cycles, thus giving the clue to control dynamic behaviors of gas adsorption.

Survey of Postharvest Quality Characteristics During Long-Term Farmers Stock Storage

USDA-ARS?s Scientific Manuscript database

The length of time that peanuts remain in farmers stock storage is variable. With the record harvest of the 2012 peanut crop, some peanuts remained in farmers stock storage for up to 12 months before being shelled and placed in cold storage or shipped to the manufacturer. To investigate potential ...

Molten salt thermal energy storage subsystem for Solar Thermal Central Receiver plants

NASA Astrophysics Data System (ADS)

Wells, P. B.; Nassopoulos, G. P.

The development of a low-cost thermal energy storage subsystem for large solar plants is analyzed. Molten nitrate salt is used as both the plant's working fluid and as the storage medium. The storage system comprises a specially designed hot tank to hold salt at a storage temperature of 839 K (1050 F) and a separate carbon steel cold tank to hold the salt after its thermal energy has been extracted to generate steam. The hot tank is lined with insulating firebrick to lower the shell temperature to 561 K (550 F) so that a low-cost carbon steel shell can be used. A preliminary design is described for a large commercial-size plant (1200 MWht). Also described are a laboratory test program for the critical components and the design, construction, and test of a small-scale research experiment at the Central Receiver Test Facility in Albuquerque, New Mexico.

Yolk–shell Fe 2O 3 ⊙ C composites anchored on MWNTs with enhanced lithium and sodium storage

DOE PAGES

Zhao, Yi; Feng, Zhenxing; Xu, Zhichuan J.

2015-04-24

For this research, a unique architecture with yolk–shell Fe 2O 3 ⊙ C composites attached to the surface of MWNTs is designed. Benefiting from the good electrical conductivity of MWNTs and carbon layers, as well as the large void space to accommodate the volume expansion/extraction of Fe 2O 3 during battery cycling, the obtained MWNT@Fe 2O 3 ⊙ C exhibited outstanding lithium and sodium storage performance.

Facile green in situ synthesis of Mg/CuO core/shell nanoenergetic arrays with a superior heat-release property and long-term storage stability.

PubMed

Zhou, Xiang; Xu, Daguo; Zhang, Qiaobao; Lu, Jian; Zhang, Kaili

2013-08-14

We report a facile green method for the in situ synthesis of Mg/CuO core/shell nanoenergetic arrays on silicon, with Mg nanorods as the core and CuO as the shell. Mg nanorods are first prepared by glancing angle deposition. CuO is then deposited around the Mg nanorods by reactive magnetron sputtering to realize the core/shell structure. Various characterization techniques are used to investigate the prepared Mg/CuO core/shell nanoenergetic arrays, including scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction, and thermal analysis. Uniform mixing and intimate contact between the Mg nanorods and CuO are confirmed from both visual inspection of the morphological images and analyses of the heat-release curves. The nanoenergetic arrays exhibit a low-onset reaction temperature (∼300 °C) and high heat of reaction (∼3400 J/g). Most importantly, the nanoenergetic arrays possess long-term storage stability resulting from the stable CuO shell. This study provides a potential general strategy for the synthesis of various Mg nanorod-based stable nanoenergetic arrays.

Microencapsulation of metal-based phase change material for high-temperature thermal energy storage.

PubMed

Nomura, Takahiro; Zhu, Chunyu; Sheng, Nan; Saito, Genki; Akiyama, Tomohiro

2015-03-13

Latent heat storage using alloys as phase change materials (PCMs) is an attractive option for high-temperature thermal energy storage. Encapsulation of these PCMs is essential for their successful use. However, so far, technology for producing microencapsulated PCMs (MEPCMs) that can be used above 500°C has not been established. Therefore, in this study, we developed Al-Si alloy microsphere MEPCMs covered by α-Al2O3 shells. The MEPCM was prepared in two steps: (1) the formation of an AlOOH shell on the PCM particles using a boehmite treatment, and (2) heat-oxidation treatment in an O2 atmosphere to form a stable α-Al2O3 shell. The MEPCM presented a melting point of 573°C and latent heat of 247 J g(-1). The cycling performance showed good durability. These results indicated the possibility of using MEPCM at high temperatures. The MEPCM developed in this study has great promise in future energy and chemical processes, such as exergy recuperation and process intensification.

Microencapsulation of Metal-based Phase Change Material for High-temperature Thermal Energy Storage

NASA Astrophysics Data System (ADS)

Nomura, Takahiro; Zhu, Chunyu; Sheng, Nan; Saito, Genki; Akiyama, Tomohiro

2015-03-01

Latent heat storage using alloys as phase change materials (PCMs) is an attractive option for high-temperature thermal energy storage. Encapsulation of these PCMs is essential for their successful use. However, so far, technology for producing microencapsulated PCMs (MEPCMs) that can be used above 500°C has not been established. Therefore, in this study, we developed Al-Si alloy microsphere MEPCMs covered by α-Al2O3 shells. The MEPCM was prepared in two steps: (1) the formation of an AlOOH shell on the PCM particles using a boehmite treatment, and (2) heat-oxidation treatment in an O2 atmosphere to form a stable α-Al2O3 shell. The MEPCM presented a melting point of 573°C and latent heat of 247 J g-1. The cycling performance showed good durability. These results indicated the possibility of using MEPCM at high temperatures. The MEPCM developed in this study has great promise in future energy and chemical processes, such as exergy recuperation and process intensification.

Impact parameter sensitive study of inner-shell atomic processes in the experimental storage ring

NASA Astrophysics Data System (ADS)

Gumberidze, A.; Kozhuharov, C.; Zhang, R. T.; Trotsenko, S.; Kozhedub, Y. S.; DuBois, R. D.; Beyer, H. F.; Blumenhagen, K.-H.; Brandau, C.; Bräuning-Demian, A.; Chen, W.; Forstner, O.; Gao, B.; Gassner, T.; Grisenti, R. E.; Hagmann, S.; Hillenbrand, P.-M.; Indelicato, P.; Kumar, A.; Lestinsky, M.; Litvinov, Yu. A.; Petridis, N.; Schury, D.; Spillmann, U.; Trageser, C.; Trassinelli, M.; Tu, X.; Stöhlker, Th.

2017-10-01

In this work, we present a pilot experiment in the experimental storage ring (ESR) at GSI devoted to impact parameter sensitive studies of inner shell atomic processes for low-energy (heavy-) ion-atom collisions. The experiment was performed with bare and He-like xenon ions (Xe54+, Xe52+) colliding with neutral xenon gas atoms, resulting in a symmetric collision system. This choice of the projectile charge states was made in order to compare the effect of a filled K-shell with the empty one. The projectile and target X-rays have been measured at different observation angles for all impact parameters as well as for the impact parameter range of ∼35-70 fm.

Tailoring surface plasmon resonance and dipole cavity plasmon modes of scattering cross section spectra on the single solid-gold/gold-shell nanorod

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chou Chau, Yuan-Fong, E-mail: chou.fong@ubd.edu.bn; Lim, Chee Ming; Kumara, N. T. R. N.

Tunable surface plasmon resonance (SPR) and dipole cavity plasmon modes of the scattering cross section (SCS) spectra on the single solid-gold/gold-shell nanorod have been numerically investigated by using the finite element method. Various effects, such as the influence of SCS spectra under x- and y-polarizations on the surface of the single solid-gold/gold-shell nanorod, are discussed in detail. With the single gold-shell nanorod, one can independently tune the relative SCS spectrum width by controlling the rod length and rod diameter, and the surface scattering by varying the shell thickness and polarization direction, as well as the dipole peak energy. These behaviorsmore » are consistent with the properties of localized SPRs and offer a way to optically control and produce selected emission wavelengths from the single solid-gold/gold-shell nanorod. The electric field and magnetic distributions provide us a qualitative idea of the geometrical properties of the single solid-gold/gold-shell nanorod on plasmon resonance.« less

Tailoring surface plasmon resonance and dipole cavity plasmon modes of scattering cross section spectra on the single solid-gold/gold-shell nanorod

NASA Astrophysics Data System (ADS)

Chou Chau, Yuan-Fong; Lim, Chee Ming; Lee, Chuanyo; Huang, Hung Ji; Lin, Chun-Ting; Kumara, N. T. R. N.; Yoong, Voo Nyuk; Chiang, Hai-Pang

2016-09-01

Tunable surface plasmon resonance (SPR) and dipole cavity plasmon modes of the scattering cross section (SCS) spectra on the single solid-gold/gold-shell nanorod have been numerically investigated by using the finite element method. Various effects, such as the influence of SCS spectra under x- and y-polarizations on the surface of the single solid-gold/gold-shell nanorod, are discussed in detail. With the single gold-shell nanorod, one can independently tune the relative SCS spectrum width by controlling the rod length and rod diameter, and the surface scattering by varying the shell thickness and polarization direction, as well as the dipole peak energy. These behaviors are consistent with the properties of localized SPRs and offer a way to optically control and produce selected emission wavelengths from the single solid-gold/gold-shell nanorod. The electric field and magnetic distributions provide us a qualitative idea of the geometrical properties of the single solid-gold/gold-shell nanorod on plasmon resonance.

Effect of a commercial housing system on egg quality during extended storage.

PubMed

Jones, D R; Karcher, D M; Abdo, Z

2014-05-01

Egg producers in the United States are utilizing a variety of commercial egg production systems to provide consumer choice and meet legislative requirements. Consumer egg grades in the United States were developed for conventional cage production, and it is unclear what effect alternative production systems might have on egg quality during retail and consumer home storage. The current study was undertaken to determine what changes in egg quality characteristics occur during extended cold storage for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs. During 12 wk of cold storage, egg weight, albumen height, Haugh unit, static compression shell strength, vitelline membrane strength and deformation, yolk index, shell dynamic stiffness, and whole egg total solids were monitored. Overall, aviary and enriched eggs were significantly (P < 0.05) heavier than conventional cage. Albumen height and Haugh unit (P < 0.05) were significantly greater for conventional cage than enriched eggs. Static compression shell strength was greatest (P < 0.05) for enriched eggs compared with aviary. No overall housing system effects for yolk measurements, shell dynamic stiffness, or whole egg total solids were observed. Albumen height, Haugh unit, and yolk quality measurements were all greatest at 0 and lowest at 12 wk of storage (P < 0.05). The rate of quality change among the housing systems for each measured attribute at 4, 6, and 12 wk was determined. Other than differences in the change of egg weight at 4 wk, no significant differences in the rate of quality decline were found among the housing systems. The results of the current study indicate that current US egg quality standards should effectively define quality for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs.

Mechanical properties of ANTRIX balloon film and fabrication of single cap large volume balloons

NASA Astrophysics Data System (ADS)

Suneel Kumar, B.; Sreenivasan, S.; Subba Rao, J. V.; Manchanda, R. K.

2008-11-01

The zero pressure plastic balloons used for high altitude studies are generally made from polyethylene material. Tensile properties of the thin film polymer are the key parameters for material selection due to extremely low temperature of -90 °C encountered by the balloons in the tropopause region during the ascent at equatorial latitudes. The physical and structural properties of the material determine the uniformity of the stress distribution over the entire shell. Load stresses from the suspended load propagate via load tapes heat sealed along with the gore seals as per the balloon design. A balance between this heat seal strength and the film strength is a desirable property of the basic resin in terms of the bubble strength, gauge uniformity, and long-term storage properties. In addition, the design of the top shell of the balloon and its stress distribution play an important role since only a fraction of the balloon is deployed during the filling operation and the ascent. In this paper we describe the mechanical properties of the 'ANTRIX' film developed by us and the optimized design of single cap balloons, which have been successfully used in our experiments over the past 5 years.

Safety criteria for organic watch list tanks at the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meacham, J.E., Westinghouse Hanford

1996-08-01

This document reviews the hazards associated with the storage of organic complexant salts in Hanford Site high-level waste single- shell tanks. The results of this analysis were used to categorize tank wastes as safe, unconditionally safe, or unsafe. Sufficient data were available to categorize 67 tanks; 63 tanks were categorized as safe, and four tanks were categorized as conditionally safe. No tanks were categorized as unsafe. The remaining 82 SSTs lack sufficient data to be categorized.Historic tank data and an analysis of variance model were used to prioritize the remaining tanks for characterization.

75 FR 48973 - Draft Guidance for Industry: Prevention of Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-12

...] Draft Guidance for Industry: Prevention of Salmonella Enteritidis in Shell Eggs During Production... entitled ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation'' (the draft guidance). The draft guidance, when finalized, will provide guidance to egg producers...

Combined approach of shell and shear-warp rendering for efficient volume visualization

NASA Astrophysics Data System (ADS)

Falcao, Alexandre X.; Rocha, Leonardo M.; Udupa, Jayaram K.

2003-05-01

In Medical Imaging, shell rendering (SR) and shear-warp rendering (SWR) are two ultra-fast and effective methods for volume visualization. We have previously shown that, typically, SWR can be on the average 1.38 times faster than SR, but it requires from 2 to 8 times more memory space than SR. In this paper, we propose an extension of the compact shell data structure utilized in SR to allow shear-warp factorization of the viewing matrix in order to obtain speed up gains for SR, without paying the high storage price of SWR. The new approach is called shear-warp shell rendering (SWSR). The paper describes the methods, points out their major differences in the computational aspects, and presents a comparative analysis of them in terms of speed, storage, and image quality. The experiments involve hard and fuzzy boundaries of 10 different objects of various sizes, shapes, and topologies, rendered on a 1GHz Pentium-III PC with 512MB RAM, utilizing surface and volume rendering strategies. The results indicate that SWSR offers the best speed and storage characteristics compromise among these methods. We also show that SWSR improves the rendition quality over SR, and provides renditions similar to those produced by SWR.

Gamma radiation induced oxidation and tocopherols decrease in in-shell, peeled and blanched peanuts.

PubMed

de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-D'Arce, Marisa Aparecida Bismara; de Alencar, Severino Matias; Calori-Domingues, Maria Antonia; Canniatti-Brazaca, Solange Guidolin

2012-01-01

In-shell, peeled and blanched peanut samples were characterized in relation to proximate composition and fatty acid profile. No difference was found in relation to its proximate composition. The three major fatty acids were palmitic acid, oleic acid, and linoleic acid. In order to investigate irradiation and storage effects, peanut samples were submitted to doses of 0.0, 5.0, 7.5 or 10.0 kGy, stored for six months at room temperature and monitored every three months. Peanuts responded differently to irradiation, particularly with regards to tocopherol contents, primary and secondary oxidation products and oil stability index. Induction periods and tocopherol contents were negatively correlated with irradiation doses and decreased moderately during storage. α-Tocopherol was the most gamma radiation sensitive and peeled samples were the most affected. A positive correlation was found among tocopherol contents and the induction period of the oils extracted from irradiated samples. Gamma radiation and storage time increased oxidation compounds production. If gamma radiation is considered an alternative for industrial scale peanut conservation, in-shell samples are the best feedstock. For the best of our knowledge this is the first article with such results; this way it may be helpful as basis for future studies on gamma radiation of in-shell crops.

Gamma Radiation Induced Oxidation and Tocopherols Decrease in In-Shell, Peeled and Blanched Peanuts

PubMed Central

de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-D’Arce, Marisa Aparecida Bismara; de Alencar, Severino Matias; Calori-Domingues, Maria Antonia; Canniatti-Brazaca, Solange Guidolin

2012-01-01

In-shell, peeled and blanched peanut samples were characterized in relation to proximate composition and fatty acid profile. No difference was found in relation to its proximate composition. The three major fatty acids were palmitic acid, oleic acid, and linoleic acid. In order to investigate irradiation and storage effects, peanut samples were submitted to doses of 0.0, 5.0, 7.5 or 10.0 kGy, stored for six months at room temperature and monitored every three months. Peanuts responded differently to irradiation, particularly with regards to tocopherol contents, primary and secondary oxidation products and oil stability index. Induction periods and tocopherol contents were negatively correlated with irradiation doses and decreased moderately during storage. α-Tocopherol was the most gamma radiation sensitive and peeled samples were the most affected. A positive correlation was found among tocopherol contents and the induction period of the oils extracted from irradiated samples. Gamma radiation and storage time increased oxidation compounds production. If gamma radiation is considered an alternative for industrial scale peanut conservation, in-shell samples are the best feedstock. For the best of our knowledge this is the first article with such results; this way it may be helpful as basis for future studies on gamma radiation of in-shell crops. PMID:22489128

Tuning the Shell Number of Multishelled Metal Oxide Hollow Fibers for Optimized Lithium-Ion Storage.

PubMed

Sun, Jin; Lv, Chunxiao; Lv, Fan; Chen, Shuai; Li, Daohao; Guo, Ziqi; Han, Wei; Yang, Dongjiang; Guo, Shaojun

2017-06-27

Searching the long-life transition-metal oxide (TMO)-based materials for future lithium-ion batteries (LIBs) is still a great challenge because of the mechanical strain resulting from volume change of TMO anodes during the lithiation/delithiation process. To well address this challenging issue, we demonstrate a controlled method for making the multishelled TMO hollow microfibers with tunable shell numbers to achieve the optimal void for efficient lithium-ion storage. Such a particularly designed void can lead to a short diffusion distance for fast diffusion of Li + ions and also withstand a large volume variation upon cycling, both of which are the key for high-performance LIBs. Triple-shelled TMO hollow microfibers are a quite stable anode material for LIBs with high reversible capacities (NiO: 698.1 mA h g -1 at 1 A g -1 ; Co 3 O 4 : 940.2 mA h g -1 at 1 A g -1 ; Fe 2 O 3 : 997.8 mA h g -1 at 1 A g -1 ), excellent rate capability, and stability. The present work opens a way for rational design of the void of multiple shells in achieving the stable lithium-ion storage through the biomass conversion strategy.

Chemical Safety Alert: Catastrophic Failure of Storage Tanks

EPA Pesticide Factsheets

Aboveground, atmospheric storage tanks can fail when flammable vapors in the tank explode and break either the shell-to-bottom or side seam, resulting in hazardous release accidents. Proper maintenance practices can help prevent accidents.

Atomic layer deposition of TiO2 shells on MoO3 nanobelts allowing enhanced lithium storage performance.

PubMed

Xie, Sanmu; Cao, Daxian; She, Yiyi; Wang, Hongkang; Shi, Jian-Wen; Leung, Micheal K H; Niu, Chunming

2018-06-26

Atomic layer deposition (ALD) of TiO2 shells on MoO3 nanobelts (denote as TiO2@MoO3) is realized using a home-made ALD system, which allows a controllable hydrolysis reaction of TiCl4-H2O on an atomic scale. When used as an anode material for lithium ion batteries, the TiO2@MoO3 electrode demonstrates much enhanced lithium storage performance including higher specific capacity, better cycling stability and rate capability.

Quasi-hexagonal Cu1.5Mn1.5O4 nanoplates decorated on hollow CuO by Kirkendall effect for enhancing lithium storage performance

NASA Astrophysics Data System (ADS)

Liu, Peng; Xia, Xifeng; Lei, Wu; Jiao, Xinyan; Lu, Lei; Ouyang, Yu; Hao, Qingli

2018-07-01

Constructing a hierarchical heterogeneous composite is deemed as an effective way to solve the current problems of metal oxides as lithium ion batteries' anodes. In this work, we simultaneously designed the heterogeneous component and structure of the novel hybrid based on Kirkendall effect. The composite was composed of quasi-hexagonal Cu1.5Mn1.5O4 nanoplates as a shell and CuO with voids as a core. The hybrids were characterized by using XRD, FTIR, TEM and SEM. It was found that the heating rate greatly influences the combination form of Cu1.5Mn1.5O4 and CuO. The quasi-hexagonal Cu1.5Mn1.5O4 nanoplates were assembled into branch-like shell decorated on the CuO surface under the low heating rate. However, the high heating rate led to a compact Cu1.5Mn1.5O4 shell, although the shell was also assembled by quasi-hexagonal nanoplates. The reasonable formation mechanism of the unique component and structure was proposed. Such a hybrid with the branch-like shell exhibited the best lithium storage performance. The improved electrochemical performance can be attributed to the unique component and structure. Typically, the inside voids can alleviate the volume change and the hierarchical shell can provide much contact and reaction sites. This work not only opens a new view in constructing heterogeneous hybrid with unique structure by Kirkendall effect, but also can be expanded for many other structure-based applications, such as energy storage, sensors, and heterogeneous catalysts.

Amorphous TiO2 Shells: A Vital Elastic Buffering Layer on Silicon Nanoparticles for High-Performance and Safe Lithium Storage.

PubMed

Yang, Jianping; Wang, Yunxiao; Li, Wei; Wang, Lianjun; Fan, Yuchi; Jiang, Wan; Luo, Wei; Wang, Yang; Kong, Biao; Selomulya, Cordelia; Liu, Hua Kun; Dou, Shi Xue; Zhao, Dongyuan

2017-12-01

Smart surface coatings of silicon (Si) nanoparticles are shown to be good examples for dramatically improving the cyclability of lithium-ion batteries. Most coating materials, however, face significant challenges, including a low initial Coulombic efficiency, tedious processing, and safety assessment. In this study, a facile sol-gel strategy is demonstrated to synthesize commercial Si nanoparticles encapsulated by amorphous titanium oxide (TiO 2 ), with core-shell structures, which show greatly superior electrochemical performance and high-safety lithium storage. The amorphous TiO 2 shell (≈3 nm) shows elastic behavior during lithium discharging and charging processes, maintaining high structural integrity. Interestingly, it is found that the amorphous TiO 2 shells offer superior buffering properties compared to crystalline TiO 2 layers for unprecedented cycling stability. Moreover, accelerating rate calorimetry testing reveals that the TiO 2 -encapsulated Si nanoparticles are safer than conventional carbon-coated Si-based anodes. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Controllable Synthesis of Copper Oxide/Carbon Core/Shell Nanowire Arrays and Their Application for Electrochemical Energy Storage

PubMed Central

Zhan, Jiye; Chen, Minghua; Xia, Xinhui

2015-01-01

Rational design/fabrication of integrated porous metal oxide arrays is critical for the construction of advanced electrochemical devices. Herein, we report self-supported CuO/C core/shell nanowire arrays prepared by the combination of electro-deposition and chemical vapor deposition methods. CuO/C nanowires with diameters of ~400 nm grow quasi-vertically to the substrates forming three-dimensional arrays architecture. A thin carbon shell is uniformly coated on the CuO nanowire cores. As an anode of lithium ion batteries, the resultant CuO/C nanowire arrays are demonstrated to have high specific capacity (672 mAh·g−1 at 0.2 C) and good cycle stability (425 mAh·g−1 at 1 C up to 150 cycles). The core/shell arrays structure plays positive roles in the enhancement of Li ion storage due to fast ion/electron transfer path, good strain accommodation and sufficient contact between electrolyte and active materials. PMID:28347084

Dielectronic Recombination In Active Galactic Nuclei

NASA Technical Reports Server (NTRS)

Lukic, D. V.; Schnell, M.; Savin, D. W.; Altun, Z.; Badnell, N.; Brandau, C.; Schmidt, E. W.; Mueller, A.; Schippers, S.; Sprenger, F.;

METHODOLOGY AND CALCULATIONS FOR THE ASSIGNMENT OF WASTE GROUPS FOR THE LARGE UNDERGROUND WASTE STORAGE TANKS AT THE HANFORD SITE

DOE Office of Scientific and Technical Information (OSTI.GOV)

WEBER RA

2009-01-16

The Hanford Site contains 177 large underground radioactive waste storage tanks (28 double-shell tanks and 149 single-shell tanks). These tanks are categorized into one of three waste groups (A, B, and C) based on their waste and tank characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement gas release event. Assignments of waste groups to the 177 double-shell tanks and single-shell tanks, as reported in this document, are based on a Monte Carlo analysis of three criteria. Themore » first criterion is the headspace flammable gas concentration following release of retained gas. This criterion determines whether the tank contains sufficient retained gas such that the well-mixed headspace flammable gas concentration would reach 100% of the lower flammability limit if the entire tank's retained gas were released. If the volume of retained gas is not sufficient to reach 100% of the lower flammability limit, then flammable conditions cannot be reached and the tank is classified as a waste group C tank independent of the method the gas is released. The second criterion is the energy ratio and considers whether there is sufficient supernatant on top of the saturated solids such that gas-bearing solids have the potential energy required to break up the material and release gas. Tanks that are not waste group C tanks and that have an energy ratio < 3.0 do not have sufficient potential energy to break up material and release gas and are assigned to waste group B. These tanks are considered to represent a potential induced flammable gas release hazard, but no spontaneous buoyant displacement flammable gas release hazard. Tanks that are not waste group C tanks and have an energy ratio {ge} 3.0, but that pass the third criterion (buoyancy ratio < 1.0, see below) are also assigned to waste group B. Even though the designation as a waste group B (or A) tank identifies the potential for an induced flammable gas release hazard, the hazard only exists for specific operations that can release the retained gas in the tank at a rate and quantity that results in reaching 100% of the lower flammability limit in the tank headspace. The identification and evaluation of tank farm operations that could cause an induced flammable gas release hazard in a waste group B (or A) tank are included in other documents. The third criterion is the buoyancy ratio. This criterion addresses tanks that are not waste group C double-shell tanks and have an energy ratio {ge} 3.0. For these double-shell tanks, the buoyancy ratio considers whether the saturated solids can retain sufficient gas to exceed neutral buoyancy relative to the supernatant layer and therefore have buoyant displacement gas release events. If the buoyancy ratio is {ge} 1.0, that double-shell tank is assigned to waste group A. These tanks are considered to have a potential spontaneous buoyant displacement flammable gas release hazard in addition to a potential induced flammable gas release hazard. This document categorizes each of the large waste storage tanks into one of several categories based on each tank's waste characteristics. These waste group assignments reflect a tank's propensity to retain a significant volume of flammable gases and the potential of the waste to release retained gas by a buoyant displacement event. Revision 8 is the annual update of the calculations of the flammable gas Waste Groups for DSTs and SSTs.« less

Operation and maintenance of the SOL-DANCE building solar system. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-07-29

The Sol-Dance building solar heating system consists of 136 flat plate solar collectors divided evenly into two separate building systems, each providing its total output to a common thermal storage tank. An aromatic base transformer oil is circulated through a closed loop consisting of the collectors and a heat exchanger. Water from the thermal storage tank is passed through the same heat exchanger where heat from the oil is given up to the thermal storage. Back-up heat is provided by air source heat pumps. Heat is transferred from the thermal storage to the living space by liquid-to-air coils in themore » distribution ducts. Separate domestic hot water systems are provided for each building. The system consists of 2 flat plate collectors with a single 66 gallon storage tank with oil circulated in a closed loop through an external tube and shell heat exchanger. Some problems encountered and lessons learned during the project construction are listed as well as beneficial aspects and a project description. As-built drawings are provided as well as system photographs. An acceptance test plan is provided that checks the collection, thermal storage, and space and water heating subsystems and the total system installation. Predicted performance data are tabulated. Details are discussed regarding operation, maintenance, and repair, and manufacturers data are provided. (LEW)« less

Microencapsulation of Metal-based Phase Change Material for High-temperature Thermal Energy Storage

PubMed Central

Nomura, Takahiro; Zhu, Chunyu; Sheng, Nan; Saito, Genki; Akiyama, Tomohiro

2015-01-01

Latent heat storage using alloys as phase change materials (PCMs) is an attractive option for high-temperature thermal energy storage. Encapsulation of these PCMs is essential for their successful use. However, so far, technology for producing microencapsulated PCMs (MEPCMs) that can be used above 500°C has not been established. Therefore, in this study, we developed Al-Si alloy microsphere MEPCMs covered by α-Al2O3 shells. The MEPCM was prepared in two steps: (1) the formation of an AlOOH shell on the PCM particles using a boehmite treatment, and (2) heat-oxidation treatment in an O2 atmosphere to form a stable α-Al2O3 shell. The MEPCM presented a melting point of 573°C and latent heat of 247 J g−1. The cycling performance showed good durability. These results indicated the possibility of using MEPCM at high temperatures. The MEPCM developed in this study has great promise in future energy and chemical processes, such as exergy recuperation and process intensification. PMID:25766648

High-quality metal oxide core/shell nanowire arrays on conductive substrates for electrochemical energy storage.

PubMed

Xia, Xinhui; Tu, Jiangping; Zhang, Yongqi; Wang, Xiuli; Gu, Changdong; Zhao, Xin-Bing; Fan, Hong Jin

2012-06-26

The high performance of a pseudocapacitor electrode relies largely on a scrupulous design of nanoarchitectures and smart hybridization of bespoke active materials. We present a powerful two-step solution-based method for the fabrication of transition metal oxide core/shell nanostructure arrays on various conductive substrates. Demonstrated examples include Co(3)O(4) or ZnO nanowire core and NiO nanoflake shells with a hierarchical and porous morphology. The "oriented attachment" and "self-assembly" crystal growth mechanisms are proposed to explain the formation of the NiO nanoflake shell. Supercapacitor electrodes based on the Co(3)O(4)/NiO nanowire arrays on 3D macroporous nickel foam are thoroughly characterized. The electrodes exhibit a high specific capacitance of 853 F/g at 2 A/g after 6000 cycles and an excellent cycling stability, owing to the unique porous core/shell nanowire array architecture, and a rational combination of two electrochemically active materials. Our growth approach offers a new technique for the design and synthesis of transition metal oxide or hydroxide hierarchical nanoarrays that are promising for electrochemical energy storage, catalysis, and gas sensing applications.

Complex Nanostructures from Materials based on Metal-Organic Frameworks for Electrochemical Energy Storage and Conversion.

PubMed

Guan, Bu Yuan; Yu, Xin Yao; Wu, Hao Bin; Lou, Xiong Wen David

2017-12-01

Metal-organic frameworks (MOFs) have drawn tremendous attention because of their abundant diversity in structure and composition. Recently, there has been growing research interest in deriving advanced nanomaterials with complex architectures and tailored chemical compositions from MOF-based precursors for electrochemical energy storage and conversion. Here, a comprehensive overview of the synthesis and energy-related applications of complex nanostructures derived from MOF-based precursors is provided. After a brief summary of synthetic methods of MOF-based templates and their conversion to desirable nanostructures, delicate designs and preparation of complex architectures from MOFs or their composites are described in detail, including porous structures, single-shelled hollow structures, and multishelled hollow structures, as well as other unusual complex structures. Afterward, their applications are discussed as electrode materials or catalysts for lithium-ion batteries, hybrid supercapacitors, water-splitting devices, and fuel cells. Lastly, the research challenges and possible development directions of complex nanostructures derived from MOF-based-templates for electrochemical energy storage and conversion applications are outlined. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Environmental Assessment: Waste Tank Safety Program, Hanford Site, Richland, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-02-01

The US Department of Energy (DOE) needs to take action in the near-term, to accelerate resolution of waste tank safety issues at the Hanford Site near the City of Richland, Washington, and reduce the risks associated with operations and management of the waste tanks. The DOE has conducted nuclear waste management operations at the Hanford Site for nearly 50 years. Operations have included storage of high-level nuclear waste in 177 underground storage tanks (UST), both in single-shell tank (SST) and double-shell tank configurations. Many of the tanks, and the equipment needed to operate them, are deteriorated. Sixty-seven SSTs are presumedmore » to have leaked a total approximately 3,800,000 liters (1 million gallons) of radioactive waste to the soil. Safety issues associated with the waste have been identified, and include (1) flammable gas generation and episodic release; (2) ferrocyanide-containing wastes; (3) a floating organic solvent layer in Tank 241-C-103; (4) nuclear criticality; (5) toxic vapors; (6) infrastructure upgrades; and (7) interim stabilization of SSTs. Initial actions have been taken in all of these areas; however, much work remains before a full understanding of the tank waste behavior is achieved. The DOE needs to accelerate the resolution of tank safety concerns to reduce the risk of an unanticipated radioactive or chemical release to the environment, while continuing to manage the wastes safely.« less

Impact of egg handling and conditions during extended storage on egg quality

USDA-ARS?s Scientific Manuscript database

The international trade of shell eggs has become more important in recent years in order to feed a growing worldwide population, meet food manufacturing demands, and address supply issues during disease outbreaks or product recalls. The primary barriers for the export and import of shell eggs are: ...

Temperature/Humidity Conditions in Stacked Flexible Intermediate Bulk Containers for Shelled Peanuts

USDA-ARS?s Scientific Manuscript database

Shelled peanuts are loaded into flexible intermediate bulk containers, or totes. After loading, the 1000-kg totes are placed directly into cold storage at 3ºC and 65% relative humidity until shipment to the customer domestically in the United States or internationally requiring transport overseas. ...

Cryopreservation of veliger larvae of trumpet shell, Charonia sauliae: an essential preparation to artificial propagation

NASA Astrophysics Data System (ADS)

Kang, Kyoung Ho; Zhang, Zhifeng; Bao, Zhenmin; Shao, Mingyu

2009-09-01

Trumpet shell, Charonia sauliae, is an endangered and valuable species, but its artificial propagation protocol has not been successfully established. To estimate the possibility of cryopreservation for larvae of C. sauliae, which is a potential preparation for its artificial reproduction and further research, in this study a protocol for the cryopreservation of veliger larvae of trumpet shell was optimized. Through a two-step cryopreservation procedure, four kinds of cryoprotectants (ethylene glycol, 1, 2-propanediol, dimethyl sulfoxide and glycerol) were employed at three concentrations (1.0, 1.5 and 2.0 molL-1) respectively and survival rates of larvae were determined after a storage of 1h. The larvae frozen with these four cryoprotectants after 1 h storage were cultured, and then survival rates were determined at 24, 72 and 120 h after thawing. Dimethyl sulfoxide at a concentration of 1.5 molL-1 showed the best protective effect in all experiments ( p<0.05). And survival rates of larvae frozen with dimethyl sulfoxide were determined after 1, 7 and 15 d of storage. The survival rates of larvae frozen with 1.5 molL-1 dimethyl sulfoxide after 1 h, 1 d, 7 d and 15 d of storage were 80.77% ±7.51%, 80.34% ±11.28%, 83.10% ±9.14% and 77.23% ±6.22% respectively. No significant differences in survival rates of larvae frozen with dimethyl sulfoxide were observed after various storage periods ( p>0.05).

Gamma Irradiation of in-Shell and Blanched Peanuts Protects against Mycotoxic Fungi and Retains Their Nutraceutical Components during Long-Term Storage

PubMed Central

de Camargo, Adriano Costa; de Souza Vieira, Thais Maria Ferreira; Regitano-d’Arce, Marisa Aparecida Bismara; de Alencar, Severino Matias; Calori-Domingues, Maria Antonia; Spoto, Marta Helena Fillet; Canniatti-Brazaca, Solange Guidolin

2012-01-01

Peanut samples were irradiated (0.0, 5.2, 7.2 or 10.0 kGy), stored for a year (room temperature) and examined every three months. Mycotoxic fungi (MF) were detected in non-irradiated blanched peanuts. A dose of 5.2 kGy was found suitable to prevent MF growth in blanched samples. No MF was detected in in-shell peanuts, with or without irradiation. The colors of the control in-shell and blanched samples were, respectively, 44.72 and 60.21 (L *); 25.20 and 20.38 (Chroma); 53.05 and 86.46 (°Hue). The water activities (Aw) were 0.673 and 0.425. The corresponding fatty acids were 13.33% and 12.14% (C16:0), 44.94% and 44.92% (C18:1, ω9) and 37.10% and 37.63% (C18:2, ω6). The total phenolics (TP) were 4.62 and 2.52 mg GAE/g, with antioxidant activities (AA) of 16.97 and 10.36 μmol TEAC/g. Storage time negatively correlated with Aw (in-shell peanuts) or L *, linoleic acid, TP and AA (in-shell and blanched peanuts) but positively correlated with Aw (blanched peanuts), and with oleic acid (in-shell and blanched peanuts). Irradiation positively correlated with antioxidant activity (blanched peanuts). No correlation was found between irradiation and AA (in-shell samples) or fatty acids and TP (in-shell and blanched peanuts). Irradiation protected against MF and retained both the polyunsaturated fatty acids and polyphenols in the samples. PMID:23109830

Survival of Salmonella enterica serovar infantis on and within stored table eggs.

PubMed

Lublin, Avishai; Maler, Ilana; Mechani, Sara; Pinto, Riky; Sela-Saldinger, Shlomo

2015-02-01

Contaminated table eggs are considered a primary source of foodborne salmonellosis globally. Recently, a single clone of Salmonella enterica serovar Infantis emerged in Israel and became the predominant serovar isolated in poultry. This clone is currently the most prevalent strain in poultry and is the leading cause of salmonellosis in humans. Because little is known regarding the potential transmission of this strain from contaminated eggs to humans, the objective of this study was to evaluate the ability of Salmonella Infantis to survive on the eggshell or within the egg during cold storage or at room temperature. Salmonella cells (5.7 log CFU per egg) were inoculated on the surface of 120 intact eggs or injected into the egg yolk (3.7 log CFU per egg) of another 120 eggs. Half of the eggs were stored at 5.5 ± 0.3°C and half at room temperature (25.5 ± 0.1°C) for up to 10 weeks. At both temperatures, the number of Salmonella cells on the shell declined by 2 log up to 4 weeks and remained constant thereafter. Yolk-inoculated Salmonella counts at cold storage declined by 1 log up to 4 weeks and remained constant, while room-temperature storage supported the growth of the pathogen to a level of 8 log CFU/ml of total egg content, as early as 4 weeks postinoculation. Examination of egg content following surface inoculation revealed the presence of Salmonella in a portion of the eggs at both temperatures up to 10 weeks, suggesting that this strain can also penetrate through the shell and survive within the egg. These findings imply that Salmonella enterica serovar Infantis is capable of survival both on the exterior and interior of table eggs and even multiply inside the egg at room temperature. Our findings support the need for prompt refrigeration to prevent Salmonella multiplication during storage of eggs at room temperature.

Effects of pre- or post-processing storage conditions on high-hydrostatic pressure inactivation of Vibrio parahaemolyticus and V. vulnificus in oysters.

PubMed

Ye, Mu; Huang, Yaoxin; Gurtler, Joshua B; Niemira, Brendan A; Sites, Joseph E; Chen, Haiqiang

2013-05-15

The effects of storage conditions on subsequent high-hydrostatic pressure (HHP) inactivation of Vibrio parahaemolyticus and Vibrio vulnificus in oysters were investigated. Live oysters were inoculated with V. parahaemolyticus or V. vulnificus to ca. 7-8 log MPN/g by feeding and stored at varying conditions (i.e., 21 or 35 °C for 5h, 4 or 10 °C for 1 and 2 days and -18 °C for 2 weeks). Oyster meats were then treated at 225-300 MPa for 2 min at 4, 21 or 35 °C. HHP at 300 MPa for 2 min achieved a >5-log MPN/g reduction of V. parahaemolyticus, completely inactivating V. vulnificus (negative by enrichment) in oysters. Treatment temperatures of 4, 21 and 35 °C did not significantly affect pressure inactivation of V. parahaemolyticus or V. vulnificus (P>0.05). Cold storage at -18, 4 and 10 °C, prior to HHP, decreased V. parahaemolyticus or V. vulnificus populations by 1.5-3.0 log MPN/g, but did not increase their sensitivity to subsequent HHP treatments. The effects of cold storage after HHP on inactivation of V. parahaemolyticus in oysters were also determined. Oysters were inoculated with V. parahaemolyticus and stored at 21 °C for 5h or 4 °C for 1 day. Oyster meats were then treated at 250-300 MPa for 2 min at 21 or 35 °C and stored for 15 days in ice or in a freezer. V. parahaemolyticus populations in HHP-treated oysters gradually decreased during post-HHP ice or frozen storage. A validation study using whole-shell oysters was conducted to determine whether the presence of oyster shells influenced HHP inactivation of V. parahaemolyticus. No appreciable differences in inactivation between shucked oyster meat and whole-shell oysters were observed. HPP at 300 MPa for 2 min at 21 °C, followed by 5-day ice storage or 7-day frozen storage, and HPP at 250 MPa for 2 min at 21 °C, followed by 10-day ice or 7-day frozen storage, completely inactivated V. parahaemolyticus in whole-shell oysters (>7 log reductions). The combination of HHP at a relatively low pressure (e.g., 250 MPa) followed by short-term frozen storage (7 days) could potentially be applied by the shellfish industry as a post-harvest process to eliminate V. parahaemolyticus in oysters. Copyright © 2013 Elsevier B.V. All rights reserved.

Soil load above Hanford waste storage tanks (2 volumes)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pianka, E.W.

1995-01-25

This document is a compilation of work performed as part of the Dome Load Control Project in 1994. Section 2 contains the calculations of the weight of the soil over the tank dome for each of the 75-feet-diameter waste-storage tanks located at the Hanford Site. The chosen soil specific weight and soil depth measured at the apex of the dome crown are the same as those used in the primary analysis that qualified the design. Section 3 provides reference dimensions for each of the tank farm sites. The reference dimensions spatially orient the tanks and provide an outer diameter formore » each tank. Section 4 summarizes the available soil surface elevation data. It also provides examples of the calculations performed to establish the present soil elevation estimates. The survey data and other data sources from which the elevation data has been obtained are printed separately in Volume 2 of this Supporting Document. Section 5 contains tables that provide an overall summary of the present status of dome loads. Tables summarizing the load state corresponding to the soil depth and soil specific weight for the original qualification analysis, the gravity load requalification for soil depth and soil specific weight greater than the expected actual values, and a best estimate condition of soil depth and specific weight are presented for the Double-Shell Tanks. For the Single-Shell Tanks, only the original qualification analysis is available; thus, the tabulated results are for this case only. Section 6 provides a brief overview of past analysis and testing results that given an indication of the load capacity of the waste storage tanks that corresponds to a condition approaching ultimate failure of the tank. 31 refs.« less

Installation guidelines for solar heating system, single-family residence at William OBrien State Park, Stillwater, Minnesota

NASA Technical Reports Server (NTRS)

1980-01-01

Installation procedures for the single family residential solar heating system at the William O'Brien State Park, Stillwater, Minnesota, are presented. The system is a solar-assisted, hydronic-to-warm-air system with solar-assisted domestic water heating. It is composed of the following major components: liquid cooled flat plate collectors; water storage tank; passive solar-fired domestic water preheater; electric hot water heater; heat pump with electric backup; solar hot water coil unit; tube-and-shell heat exchanger, three pumps, and associated pipes and valving in an energy transport module; control system; and air-cooled heat purge unit. Installer guidelines are provided for each subsystem and includes testing and filling the system. Information is also given on the operating procedures, controls, caution requirements and routine and schedule maintenance.

Installation guidelines for solar heating system, single-family residence at New Castle, Pennsylvania

NASA Technical Reports Server (NTRS)

1980-01-01

The solar heating system installer guidelines are presented for each subsystem. This single family residential heating system is a solar-assisted, hydronic-to-warm-air system with solar-assisted domestic water heating. It is composed of the following major components: (1) liquid cooled flat plate collectors; (2) water storage tank; (3) passive solar-fired domestic water preheater; (4) electric hot water heater; (5) heat pump with electric backup; (6) solar hot water coil unit; (7) tube-and-shell heat exchanger, three pumps, and associated pipes and valving in an energy transport module; (8) control system; and (9) air-cooled heat purge unit. Information is provided on the operating procedures, controls, caution requirements, and routine and schedule maintenance in the form of written descriptions, schematics, detail drawings, pictures, and manufacturer's component data.

Molten salt thermal energy storage subsystem for solar thermal central receiver plants

NASA Astrophysics Data System (ADS)

Wells, P. B.; Nassopoulos, G. P.

1982-02-01

The development of a low cost thermal energy storage subsystem for large solar plants is described. Molten nitrate salt is used as both the solar plant working fluid and the storage medium. The storage system consists of a specially designed hot tank to hold salt at a storage temperature of 839K (1050 deg F) and a separate carbon steel cold tank to hold the salt after its thermal energy has been extracted to generate steam. The hot tank is lined with insulating firebrick to reduce the shell temperature to 561K (550 deg F) so that a low cost carbon steel shell is used. The internal insulation is protected from the hot salt by a unique metal liner with orthogonal corrugations to allow for numerous cycles of thermal expansion and contraction. A preliminary design for a large commercial size plant (1200 MWh sub +), a laboratory test program for the critical components, and the design, construction, and test of a small scale (7 MWH sub t) research experiment at the Central Receiver Test Facility in Albuquerque, New Mexico is described.

Controllable Synthesis of Functional Hollow Carbon Nanostructures with Dopamine As Precursor for Supercapacitors.

PubMed

Liu, Chao; Wang, Jing; Li, Jiansheng; Luo, Rui; Shen, Jinyou; Sun, Xiuyun; Han, Weiqing; Wang, Lianjun

2015-08-26

N-doped hollow carbon spheres (N-HCSs) are promising candidates as electrode material for supercapacitor application. In this work, we report a facile one-step synthesis of discrete and highly dispersible N-HCSs with dopamine (DA) as a carbon precursor and TEOS as a structure-assistant agent in a mixture containing water, ethanol, and ammonia. The architectures of resultant N-HCSs, including yolk-shell hollow carbon spheres (YS-HCSs), single-shell hollow carbon spheres (SS-HCSs), and double-shells hollow carbon spheres (DS-HCSs), can be efficiently controlled through the adjustment of the amount of ammonia. To explain the relation and formation mechanism of these hollow carbon structures, the samples during the different synthetic steps, including polymer/silica spheres, carbon/silica spheres and silica spheres by combustion in air, were characterized by TEM. Electrochemical measurements performed on YS-HCSs, SS-HCSs, and DS-HCSs showed high capacitance with 215, 280, and 381 F g(-1), respectively. Moreover, all the nitrogen-doped hollow carbon nanospheres showed a good cycling stability 97.0% capacitive retention after 3000 cycles. Notably, the highest capacitance of DS-HCSs up to 381 F g(-1) is higher than the capacitance reported so far for many carbon-based materials, which may be attributed to the high surface area, hollow structure, nitrogen functionalization, and double-shell architecture. These kinds of N-doped hollow-structured carbon spheres may show promising prospects as advanced energy storage materials and catalyst supports.

77 FR 14022 - Guidance for Industry: Testing for Salmonella Species in Human Foods and Direct-Human-Contact...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-08

... not apply to egg producers and other persons who are covered by FDA's final rule ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation.'' The guidance addresses testing procedures for Salmonella species (spp.) in human foods (except shell eggs) and direct-human...

The Effect of Negative-pressure Microcrack Imaging on Egg Quality during Storage

USDA-ARS?s Scientific Manuscript database

Microcracks are very small cracks in the shell surface which are difficult to detect by human graders. Microcracks have both food safety and quality implications since the shell is recognized as the first line of defense for the egg. New technology was developed which utilizes a brief negative pr...

Quality changes in macadamia kernel between harvest and farm-gate.

PubMed

Walton, David A; Wallace, Helen M

2011-02-01

Macadamia integrifolia, Macadamia tetraphylla and their hybrids are cultivated for their edible kernels. After harvest, nuts-in-shell are partially dried on-farm and sorted to eliminate poor-quality kernels before consignment to a processor. During these operations, kernel quality may be lost. In this study, macadamia nuts-in-shell were sampled at five points of an on-farm postharvest handling chain from dehusking to the final storage silo to assess quality loss prior to consignment. Shoulder damage, weight of pieces and unsound kernel were assessed for raw kernels, and colour, mottled colour and surface damage for roasted kernels. Shoulder damage, weight of pieces and unsound kernel for raw kernels increased significantly between the dehusker and the final silo. Roasted kernels displayed a significant increase in dark colour, mottled colour and surface damage during on-farm handling. Significant loss of macadamia kernel quality occurred on a commercial farm during sorting and storage of nuts-in-shell before nuts were consigned to a processor. Nuts-in-shell should be dried as quickly as possible and on-farm handling minimised to maintain optimum kernel quality. 2010 Society of Chemical Industry.

Facile and low energy consumption synthesis of microencapsulated phase change materials with hybrid shell for thermal energy storage

NASA Astrophysics Data System (ADS)

Wang, Hao; Zhao, Liang; Chen, Lijie; Song, Guolin; Tang, Guoyi

2017-12-01

We designed a photocurable pickering emulsion polymerization to create microencapsulated phase change materials (MicroPCM) with polymer-silica hybrid shell. The emulsion was stabilized by modified SiO2 particles without any surfactant or dispersant. The polymerization process can be carried out at ambient temperature only for 5 min ultraviolet radiation, which is a low-energy procedure. The resultant capsules were shown a good core-shell structure and uniform in size. The surface of the microcapsules was covered by SiO2 particles. According to the DSC and TGA examinations, the microcapsules has good thermal energy storage-release performance, enhanced thermal reliability and thermal stability. When ratio of MMA/n-octadecane was 1.5/1.5. The encapsulation efficiency of the microcapsules reached 62.55%, accompanied with 122.31 J/g melting enthalpy. The work is virtually applicable to the construction of a wide variety of organic-inorganic hybrid shell MicroPCM. Furthermore, with the application of this method, exciting opportunities may arise for realizing rapid, continuous and large-scale industrial preparation of MicroPCM.

Recombination of open-f-shell tungsten ions

NASA Astrophysics Data System (ADS)

Krantz, C.; Badnell, N. R.; Müller, A.; Schippers, S.; Wolf, A.

2017-03-01

We review experimental and theoretical efforts aimed at a detailed understanding of the recombination of electrons with highly charged tungsten ions characterised by an open 4f sub-shell. Highly charged tungsten occurs as a plasma contaminant in ITER-like tokamak experiments, where it acts as an unwanted cooling agent. Modelling of the charge state populations in a plasma requires reliable thermal rate coefficients for charge-changing electron collisions. The electron recombination of medium-charged tungsten species with open 4f sub-shells is especially challenging to compute reliably. Storage-ring experiments have been conducted that yielded recombination rate coefficients at high energy resolution and well-understood systematics. Significant deviations compared to simplified, but prevalent, computational models have been found. A new class of ab initio numerical calculations has been developed that provides reliable predictions of the total plasma recombination rate coefficients for these ions.

Manipulating the architecture of bimetallic nanostructures and their plasmonic properties

NASA Astrophysics Data System (ADS)

DeSantis, Christopher John

There has been much interest in colloidal noble metal nanoparticles due to their fascinating plasmonic and catalytic properties. These properties make noble metal nanoparticles potentially useful for applications such as targeted drug delivery agents and hydrogen storage devices. Historically, shape-controlled noble metal nanoparticles have been predominantly monometallic. Recent synthetic advances provide access to bimetallic noble metal nanoparticles wherein their inherent multifunctionality and ability to fine tune or expand their surface chemistry and light scattering properties of metal nanoparticles make them popular candidates for many applications. Even so, there are currently few synthetic strategies to rationally design shape-controlled bimetallic nanocrystals; for this reason, few architectures are accessible. For example, the "seed-mediated method" is a popular means of achieving monodisperse shape-controlled bimetallic nanocrystals. In this process, small metal seeds are used as platforms for additional metal addition, allowing for conformal core shell nanostructures. However, this method has only been applied to single metal core/single metal shell structures; therefore, the surface compositions and architectures achievable are limited. This thesis expands upon the seed-mediated method by coupling it with co-reduction. In short, two metal precursors are simultaneously reduced to deposit metal onto pre-formed seeds in hopes that the interplay between two metal species facilitates bimetallic shell nanocrystals. Au/Pd was used as a test system due to favorable reduction potentials of metal precursors and good lattice match between Au and Pd. Alloyed shelled Au Au/Pd nanocrystals were achieved using this "seed-mediated co-reduction" approach. Symmetric eight-branched Au/Pd nanocrystals (octopods) are also prepared using this method. This thesis investigates many synthetic parameters that determine the shape outcome in Au/Pd nanocrystals during seed-mediated co-reduction. Plasmonic, catalytic, and assembly properties are also investigated in relation to nanocrystal shape and architecture. This work provides a foundation for the rational design of architecturally defined bimetallic nanostructures.

Irradiation of shell egg on the physicochemical and functional properties of liquid egg white.

PubMed

Min, B; Nam, K C; Jo, C; Ahn, D U

2012-10-01

This study was aimed at determining the effect of irradiation of shell eggs on the physiochemical and functional properties of liquid egg white during storage. Color and textural parameters of irradiated liquid egg white after cooking were also determined. Shell eggs were irradiated at 0, 2.5, 5, or 10 kGy using a linear accelerator. Egg white was separated from yolk and stored in at 4°C up to 14 d. Viscosity, pH, turbidity, foaming properties, color, and volatile profile of liquid egg white, and color and texture properties of cooked egg white were determined at 0, 7, and 14 d of storage. Irradiation increased the turbidity but decreased viscosity of liquid egg white. Foaming capacity and foam stability were not affected by irradiation at lower dose (2.5 kGy), but were deteriorated at higher doses (≥5.0 kGy) of irradiation. Sulfur-containing volatiles were generated by irradiation and their amounts increased as the irradiation dose increased. However, the sulfur volatiles disappeared during storage under aerobic conditions. Lightness (L* value) and yellowness (b* value) decreased, but greenness (-a* value) increased in cooked egg white in irradiation dose-dependent manners. All textural parameters (hardness, adhesiveness, cohesiveness, chewiness, and resilience) of cooked egg white increased as the irradiation dose increased, but those changes were marginal. Our results indicated that irradiation of shell egg at lower doses (up to 2.5 kGy) had little negative impact on the physiochemical and functional properties of liquid egg white, but can improve the efficiency of egg processing due to its viscosity-lowering effect. Therefore, irradiation of shell eggs at the lower doses has high potential to be used by the egg processing industry to improve the safety of liquid egg without compromising its quality.

Green chemistry solutions for sol-gel micro-encapsulation of phase change materials for high-temperature thermal energy storage

NASA Astrophysics Data System (ADS)

Romero-Sanchez, Maria Dolores; Piticescu, Radu-Robert; Motoc, Adrian Mihail; Aran-Ais, Francisca; Tudor, Albert Ioan

2018-06-01

NaNO3 has been selected as phase change material (PCM) due to its convenient melting and crystallization temperatures for thermal energy storage (TES) in solar plants or recovering of waste heat in industrial processes. However, incorporation of PCMs and NaNO3 in particular requires its protection (i.e. encapsulation) into containers or support materials to avoid incompatibility or chemical reaction with the media where incorporated (i.e. corrosion in metal storage tanks). As a novelty, in this study, microencapsulation of an inorganic salt has been carried out also using an inorganic compound (SiO2) instead of the conventional polymeric shells used for organic microencapsulations and not suitable for high temperature applications (i.e. 300-500 °C). Thus, NaNO3 has been microencapsulated by sol-gel technology using SiO2 as shell material. Feasibility of the microparticles synthetized has been demonstrated by different experimental techniques in terms of TES capacity and thermal stability as well as durability through thermal cycles. The effectiveness of microencapsulated NaNO3 as TES material depends on the core:shell ratio used for the synthesis and on the maximum temperature supported by NaNO3 during use.

Rational design of Fe3O4@C yolk-shell nanorods constituting a stable anode for high-performance Li/Na-ion batteries.

PubMed

Wang, Beibei; Zhang, Xing; Liu, Xiaojie; Wang, Gang; Wang, Hui; Bai, Jintao

2018-05-24

In the current research project, we have prepared a novel Fe 3 O 4 @mesoporous carbon nanorod (denoted as Fe 3 O 4 @C) anode with yolk-shell structure for Li/Na-ion batteries via one-pot and surfactant-free synthesis strategy. The yolk-shell structure consists of Fe 3 O 4 nanorod yolk completely protected by a well-conductive mesoporous carbon shell. The substantial void space in the Fe 3 O 4 @C yolk-shell nanorod can not only accommodate the full volume expansion of inner Fe 3 O 4 nanorod, but also preserve the structural integrity of the Fe 3 O 4 @C anode and develop a stable SEI film on the outside mesoporous carbon shell during the repeated Li + /Na + insertion/extraction processes. As for lithium storage, the Fe 3 O 4 @C electrode exhibits a high specific capacity (1247 mAh g -1 ), stable cycling performance (a specific capacity of 954 mAh g -1 after 200 cycles at a current density of 0.5 A g -1 ) and excellent rate capability (specific capabilities of 1122, 958, 783, 577, and 374 mAh g -1 at 0.5, 1, 2, 4, and 8 A g -1 , respectively). As for sodium storage, the Fe 3 O 4 @C yolk-shell nanorods also maintain a reversible capacity of approximate 424 mAh g -1 at 0.1 A g -1 after 100 cycles. Copyright © 2018. Published by Elsevier Inc.

77 FR 50372 - Guidance for Industry: Questions and Answers Regarding the Final Rule, Prevention of Salmonella...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-21

..., Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation... Eggs During Production, Storage, and Transportation.'' The guidance contains questions we have received... egg producers and other persons who are covered by the final rule. [[Page 50373

Investigation of mechanical properties and deformation behavior of single-crystal Al-Cu core-shell nanowire generated using non-equilibrium molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Sarkar, Jit

2018-06-01

Molecular dynamics (MD) simulation studies were carried out to generate a cylindrical single-crystal Al-Cu core-shell nanowire and its mechanical properties like yield strength and Young's modulus were evaluated in comparison to a solid aluminum nanowire and hollow copper nanowire which combines to constitute the core-shell structure respectively. The deformation behavior due to changes in the number of Wigner-Seitz defects and dislocations during the entire tensile deformation process was thoroughly studied for the Al-Cu core-shell nanowire. The single-crystal Al-Cu core-shell nanowire shows much higher yield strength and Young's modulus in comparison to the solid aluminum core and hollow copper shell nanowire due to tangling of dislocations caused by lattice mismatch between aluminum and copper. Thus, the Al-Cu core-shell nanowire can be reinforced in different bulk matrix to develop new type of light-weight nanocomposite materials with greatly enhanced material properties.

Single-step generation of metal-plasma polymer multicore@shell nanoparticles from the gas phase.

PubMed

Solař, Pavel; Polonskyi, Oleksandr; Olbricht, Ansgar; Hinz, Alexander; Shelemin, Artem; Kylián, Ondřej; Choukourov, Andrei; Faupel, Franz; Biederman, Hynek

2017-08-17

Nanoparticles composed of multiple silver cores and a plasma polymer shell (multicore@shell) were prepared in a single step with a gas aggregation cluster source operating with Ar/hexamethyldisiloxane mixtures and optionally oxygen. The size distribution of the metal inclusions as well as the chemical composition and the thickness of the shells were found to be controlled by the composition of the working gas mixture. Shell matrices ranging from organosilicon plasma polymer to nearly stoichiometric SiO 2 were obtained. The method allows facile fabrication of multicore@shell nanoparticles with tailored functional properties, as demonstrated here with the optical response.

Effects of Shell-Buckling Knockdown Factors in Large Cylindrical Shells

NASA Technical Reports Server (NTRS)

Hrinda, Glenn A.

2012-01-01

Shell-buckling knockdown factors (SBKF) have been used in large cylindrical shell structures to account for uncertainty in buckling loads. As the diameter of the cylinder increases, achieving the manufacturing tolerances becomes increasingly more difficult. Knockdown factors account for manufacturing imperfections in the shell geometry by decreasing the allowable buckling load of the cylinder. In this paper, large-diameter (33 ft) cylinders are investigated by using various SBKF's. An investigation that is based on finite-element analysis (FEA) is used to develop design sensitivity relationships. Different manufacturing imperfections are modeled into a perfect cylinder to investigate the effects of these imperfections on buckling. The analysis results may be applicable to large- diameter rockets, cylindrical tower structures, bulk storage tanks, and silos.

Microscopic Shell Model Calculations for sd-Shell Nuclei

NASA Astrophysics Data System (ADS)

Barrett, Bruce R.; Dikmen, Erdal; Maris, Pieter; Shirokov, Andrey M.; Smirnova, Nadya A.; Vary, James P.

Several techniques now exist for performing detailed and accurate calculations of the structure of light nuclei, i.e., A ≤ 16. Going to heavier nuclei requires new techniques or extensions of old ones. One of these is the so-called No Core Shell Model (NCSM) with a Core approach, which involves an Okubo-Lee-Suzuki (OLS) transformation of a converged NCSM result into a single major shell, such as the sd-shell. The obtained effective two-body matrix elements can be separated into core and single-particle (s.p.) energies plus residual two-body interactions, which can be used for performing standard shell-model (SSM) calculations. As an example, an application of this procedure will be given for nuclei at the beginning ofthe sd-shell.

Preparation and characterization of SiO2-coated submicron-sized L10 Fe-Pt particles

NASA Astrophysics Data System (ADS)

Hayashi, Yoshiaki; Ogawa, Tomoyuki; Ishiyama, Kazushi

2018-05-01

The development of magnets with higher performance is attracting increasing interest. The optimization of their microstructure is essential to enhance their properties, and a microstructure comprising magnetically isolated hard magnetic grains of a single-domain size has been proposed as an ideal structure for enhancing the coercivity of magnets. To obtain magnets with an ideal structure, we consider the fabrication of magnets by an approach based on core/shell nanoparticles with a hard magnetic core and a non-magnetic shell. In this study, to obtain particles for our proposed approach, we attempted to fabricate L10 Fe-Pt/SiO2-core/shell particles with submicron-sized cores less than the critical single-domain size. The fabrication of such core/shell particles was confirmed from morphology observations and XRD analysis of the particles. Although the formation of more desirable core/shell particles with submicron-sized single-crystal cores in the single-domain size range was not achieved, the fabricated core/shell particles showed a high coercivity of 25 kOe.

An Automated Sample Divider for Farmers Stock Peanuts

USDA-ARS?s Scientific Manuscript database

In-shell peanuts are harvested, loaded into drying trailers, and delivered to a central facility where they are dried to a moisture content safe for long term storage, sampled, graded, then unloaded into bulk storage. Drying trailers have capacities ranging from five to twenty-five tons of dry farme...

An automated sample divider for farmers stock peanuts

USDA-ARS?s Scientific Manuscript database

In-shell peanuts are harvested, loaded into drying trailers, and delivered to a central facility where they are dried to a moisture content safe for long term storage, sampled, graded, then unloaded into bulk storage. Drying trailers have capacities ranging from five to twenty-five tons of dry farme...

76 FR 41157 - Guidance for Industry: Questions and Answers Regarding the Final Rule, Prevention of Salmonella...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-13

..., Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation... Eggs During Production, Storage, and Transportation'' (the draft guidance). The draft guidance provides guidance to egg producers and other persons who are covered by FDA's final rule entitled ``Prevention of...

Review of technologies for the pretreatment of retrieved single-shell tank waste at Hanford

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerber, M.A.

1992-08-01

The purpose of the study reported here was to identify and evaluate innovative processes that could be used to pretreat mixed waste retrieved from the 149 single-shell tanks (SSTs) on the US Department of Energy's (DOE) Hanford site. The information was collected as part of the Single Shell Tank Waste Treatment project at Pacific Northwest Laboratory (PNL). The project is being conducted for Westinghouse Hanford Company under their SST Disposal Program.

Review of technologies for the pretreatment of retrieved single-shell tank waste at Hanford

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerber, M.A.

1992-08-01

The purpose of the study reported here was to identify and evaluate innovative processes that could be used to pretreat mixed waste retrieved from the 149 single-shell tanks (SSTs) on the US Department of Energy`s (DOE) Hanford site. The information was collected as part of the Single Shell Tank Waste Treatment project at Pacific Northwest Laboratory (PNL). The project is being conducted for Westinghouse Hanford Company under their SST Disposal Program.

Variation in fungal microbiome (mycobiome) and aflatoxins during simulated storage of in-shell peanuts and peanut kernels.

PubMed

Xing, Fuguo; Ding, Ning; Liu, Xiao; Selvaraj, Jonathan Nimal; Wang, Limin; Zhou, Lu; Zhao, Yueju; Wang, Yan; Liu, Yang

2016-05-16

Internal transcribed spacer 2 (ITS2) sequencing was used to characterize the peanut mycobiome during 90 days storage at five conditions. The fungal diversity in in-shell peanuts was higher with 110 operational taxonomic units (OTUs) and 41 genera than peanut kernels (91 OTUs and 37 genera). This means that the micro-environment in shell is more suitable for maintaining fungal diversity. At 20-30 d, Rhizopus, Eurotium and Wallemia were predominant in in-shell peanuts. In peanut kernels, Rhizopus (>30%) and Eurotium (>20%) were predominant at 10-20 d and 30 d, respectively. The relative abundances of Rhizopus, Eurotium and Wallemia were higher than Aspergillus, because they were xerophilic and grew well on substrates with low water activity (aw). During growth, they released metabolic water, thereby favoring the growth of Aspergillus. Therefore, from 30 to 90 d, the relative abundance of Aspergillus increased while that of Rhizopus, Eurotium and Wallemia decreased. Principal Coordinate Analysis (PCoA) revealed that peanuts stored for 60-90 days and for 10-30 days clustered differently from each other. Due to low aw values (0.34-0.72) and low levels of A. flavus, nine of 51 samples were contaminated with aflatoxins.

Kinematic arguments against single relativistic shell models for GRBs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fenimore, E.E.; Ramirez, E.; Sumner, M.C.

1997-09-01

Two main types of models have been suggested to explain the long durations and multiple peaks of Gamma Ray Bursts (GRBs). In one, there is a very quick release of energy at a central site resulting in a single relativistic shell that produces peaks in the time history through its interactions with the ambient material. In the other, the central site sporadically releases energy over hundreds of seconds forming a peak with each burst of energy. The authors show that the average envelope of emission and the presence of gaps in GRBs are inconsistent with a single relativistic shell. Theymore » estimate that the maximum fraction of a single shell that can produce gamma-rays in a GRB with multiple peaks is 10{sup {minus}3}, implying that single relativistic shells require 10{sup 3} times more energy than previously thought. They conclude that either the central site of a GRB must produce {approx}10{sup 51} erg/s{sup {minus}1} for hundreds of seconds, or the relativistic shell must have structure on a scales the order of {radical}{epsilon}{Gamma}{sup {minus}1}, where {Gamma} is the bulk Lorentz factor ({approximately}10{sup 2} to 10{sup 3}) and {epsilon} is the efficiency.« less

Synthesis of Co 2SnO 4@C core-shell nanostructures with reversible lithium storage

NASA Astrophysics Data System (ADS)

Qi, Yue; Du, Ning; Zhang, Hui; Wu, Ping; Yang, Deren

This paper reports the synthesis of Co 2SnO 4@C core-shell nanostructures through a simple glucose hydrothermal and subsequent carbonization approach. The as-synthesized Co 2SnO 4@C core-shell nanostructures have been applied as anode materials for lithium-ion batteries, which exhibit improved cyclic performance compared to pure Co 2SnO 4 nanocrystals. The carbon matrix has good volume buffering effect and high electronic conductivity, which may be responsible for the improved cyclic performance.

One-pot facile synthesis of reusable tremella-like M1@M2@M1(OH)2 (M1 = Co, Ni, M2 = Pt/Pd, Pt, Pd and Au) three layers core-shell nanostructures as highly efficient catalysts

NASA Astrophysics Data System (ADS)

Liu, Yadong; Fang, Zhen; Kuai, Long; Geng, Baoyou

2014-07-01

In this work, a general, facile, successive and eco-friendly method for multilayer nanostructures has been established for the first time. We take full advantage of the structural and compositional character of M1@M2 (M1 = Co, Ni, M2 = Pt/Pd, Pt, Pd and Au) core-shell nanostructures to prepare a series of reusable tremella-like M1@M2@M1(OH)2 three layer core-shell or yolk-shell nanocomposites with a magnetic core, a porous noble metal shell, and an ultrathin cobalt or nickel hydroxide shell. We evaluated their catalytic performance using a model reaction based on the reduction of 4-nitrophenol. These novel M1@M2@M1(OH)2 nanomaterials with a unique internal micro environment promoted the efficiency of the catalytic reaction, prolonged the service life of the catalyst and enhanced the overall activity of the catalyst in the catalytic process. The novel three layer core-shell nanocomposites can be extended to other applications such as biomedical detection, energy conversion and storage systems.In this work, a general, facile, successive and eco-friendly method for multilayer nanostructures has been established for the first time. We take full advantage of the structural and compositional character of M1@M2 (M1 = Co, Ni, M2 = Pt/Pd, Pt, Pd and Au) core-shell nanostructures to prepare a series of reusable tremella-like M1@M2@M1(OH)2 three layer core-shell or yolk-shell nanocomposites with a magnetic core, a porous noble metal shell, and an ultrathin cobalt or nickel hydroxide shell. We evaluated their catalytic performance using a model reaction based on the reduction of 4-nitrophenol. These novel M1@M2@M1(OH)2 nanomaterials with a unique internal micro environment promoted the efficiency of the catalytic reaction, prolonged the service life of the catalyst and enhanced the overall activity of the catalyst in the catalytic process. The novel three layer core-shell nanocomposites can be extended to other applications such as biomedical detection, energy conversion and storage systems. Electronic supplementary information (ESI) available: Fig. S1-S6. See DOI: 10.1039/c4nr01470g

Thermal Assessment of a Latent-Heat Energy Storage Module During Melting and Freezing for Solar Energy Applications

NASA Astrophysics Data System (ADS)

Ramos Archibold, Antonio

Capital investment reduction, exergetic efficiency improvement and material compatibility issues have been identified as the primary techno-economic challenges associated, with the near-term development and deployment of thermal energy storage (TES) in commercial-scale concentrating solar power plants. Three TES techniques have gained attention in the solar energy research community as possible candidates to reduce the cost of solar-generated electricity, namely (1) sensible heat storage, (2) latent heat (tank filled with phase change materials (PCMs) or encapsulated PCMs packed in a vessel) and (3) thermochemical storage. Among these the PCM macro-encapsulation approach seems to be one of the most-promising methods because of its potential to develop more effective energy exchange, reduce the cost associated with the tank and increase the exergetic efficiency. However, the technological barriers to this approach arise from the encapsulation techniques used to create a durable capsule, as well as an assessment of the fundamental thermal energy transport mechanisms during the phase change. A comprehensive study of the energy exchange interactions and induced fluid flow during melting and solidification of a confined storage medium is reported in this investigation from a theoretical perspective. Emphasis has been placed on the thermal characterization of a single constituent storage module rather than an entire storage system, in order to, precisely capture the energy exchange contributions of all the fundamental heat transfer mechanisms during the phase change processes. Two-dimensional, axisymmetric, transient equations for mass, momentum and energy conservation have been solved numerically by the finite volume scheme. Initially, the interaction between conduction and natural convection energy transport modes, in the absence of thermal radiation, is investigated for solar power applications at temperatures (300--400°C). Later, participating thermal radiation within the storage medium has been included in order to extend the conventional natural convection-dominated model and to analyze its influence on the melting and freezing dynamics at elevated temperatures (800-850°C). A parametric analysis has been performed in order to ascertain the effects of the controlling parameters on the melting/freezing rates and the total and radiative heat transfer rates at the inner surface of the shell. The results show that the presence of thermal radiation enhances the melting and solidification processes. Finally, a simplified model of the packed bed heat exchanger with multiple spherical capsules filled with the storage medium and positioned in a vertical array inside a cylindrical container is analyzed and numerically solved. The influence of the inlet mass flow rate, inner shell surface emissivity and PCM attenuation coefficient on the melting dynamics of the PCM has been analyzed and quantified.

Decorating TiO2 Nanowires with BaTiO3 Nanoparticles: A New Approach Leading to Substantially Enhanced Energy Storage Capability of High-k Polymer Nanocomposites.

PubMed

Kang, Da; Wang, Guanyao; Huang, Yanhui; Jiang, Pingkai; Huang, Xingyi

2018-01-31

The urgent demand of high energy density and high power density devices has triggered significant interest in high dielectric constant (high-k) flexible nanocomposites comprising dielectric polymer and high-k inorganic nanofiller. However, the large electrical mismatch between polymer and nanofiller usually leads to earlier electric failure of the nanocomposites, resulting in an undesirable decrease of electrical energy storage capability. A few studies show that the introduction of moderate-k shell onto a high-k nanofiller surface can decrease the dielectric constant mismatch, and thus, the corresponding nanocomposites can withstand high electric field. Unfortunately, the low apparent dielectric enhancement of the nanocomposites and high electrical conductivity mismatch between matrix and nanofiller still result in low energy density and low efficiency. In this study, it is demonstrated that encapsulating moderate-k nanofiller with high-k but low electrical conductivity shell is effective to significantly enhance the energy storage capability of dielectric polymer nanocomposites. Specifically, using BaTiO 3 nanoparticles encapsulated TiO 2 (BaTiO 3 @TiO 2 ) core-shell nanowires as filler, the corresponding poly(vinylidene fluoride-co-hexafluoropylene) nanocomposites exhibit superior energy storage capability in comparison with the nanocomposites filled by either BaTiO 3 or TiO 2 nanowires. The nanocomposite film with 5 wt % BaTiO 3 @TiO 2 nanowires possesses an ultrahigh discharged energy density of 9.95 J cm -3 at 500 MV m -1 , much higher than that of commercial biaxial-oriented polypropylene (BOPP) (3.56 J cm -3 at 600 MV m -1 ). This new strategy and corresponding results presented here provide new insights into the design of dielectric polymer nanocomposites with high electrical energy storage capability.

Vitellogenesis in Archigetes sieboldi Leuckart, 1878 (Cestoda, Caryophyllidea, Caryophyllaeidae), an intestinal parasite of carp (Cyprinus carpio L.).

PubMed

Brunanská, M; Mackiewicz, J S; Nebesárová, J

2012-12-01

Vitellogenesis in the caryophyllidean tapeworm Archigetes sieboldi Leuckart, 1878, from carp Cyprinus carpio L. in Slovakia, has been examined using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) for glycogen. Vitelline follicles extend in two lateral bands in the medullary parenchyma along both sides of the monozoic body. They are surrounded by an external basal lamina and contain vitellocytes and an interstitial tissue. The general pattern of vitellogenesis is essentially like that of other caryophyllideans. It involves four stages: immature, early maturing, advanced maturing cells and mature vitellocytes. During vitellogenesis, a continuous increase in cell volume is accompanied by an extensive development of cell components engaged in shell globule formation, e.g. granular endoplasmic reticulum and Golgi. Shell globule clusters are membrane-bound. Nuclear and nucleolar transformation are associated with formation and storage of large amounts of intranuclear glycogen, a very specific feature of the Caryophyllidea. For the first time, (a) additional vitelline material in Archigetes is represented by lamellar bodies and (b) lipid droplets are described in the mature vitellocytes from vitelline follicles and vitelloduct of the Caryophyllidea. Our results indicate that there may be a double origin of lamellar bodies: either from the endoplasmic reticulum or through transformation of shell globule/shell globule clusters. Lamellar body clusters and some single lamellar bodies appear to have a membrane. Other ultrastructural features of vitellogenesis and/or vitellocyte in A. sieboldi from its vertebrate (fish) and invertebrate (oligochaete) hosts are briefly compared and contrasted with those in other caryophyllideans and/or Neodermata.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hall, J.; Richard, P.; Gray, T.J.

The systematics of single and double K-shell-vacancy production in titanium has been investigated in the limit of zero target thickness (approx.1 ..mu..g/cm/sup 2/) for incident C, N, O, F, Mg, Al, Si, S, and Cl ions over a maximum energy range of 0.5 to 6.5 MeV/amu. This corresponds to collision systems with 0.27< or =Z/sub 1//Z/sub 2/< or =0.77 and 0.24< or =v/sub 1//vK< or =0.85, where v/sub 1/ is the projectile nuclear velocity and vK is the mean velocity of an electron in the target K shell. The present work is divided into four major sections. (1) Single K-shell-vacancymore » production has been investigated by measuring K..cap alpha.. and K..beta.. p satellite x-ray-production cross sections for projectiles incident with no K-shell vacancies. For incident ions with Z/sub 1/> or =9, the contribution due to electron-transfer processes from the target K shell to outer shells of the projectile has also been noted. (2) Single K-shell--to--K-shell electron-transfer cross sections have been obtained indirectly by the measuring of the enhancement in the Ti K x-ray production cross section for bare incident projectiles over ions incident with no initial K-shell vacancies. (3) Double K-vacancy production has been investigated by measuring the K..cap alpha.. hypersatellite intensity in ratio to the total K..cap alpha.. intensity. (4) Double K-shell--to--K-shell electron-transfer cross sections have been obtained indirectly with the use of a procedure similar to that used for single K to K transfer. The measured cross sections have been compared to theoretical models for direct Coulomb ionization and inner-shell electron transfer and have been used to investigate the relative importance of these mechanisms for K-vacancy production in heavy-ion--atom collisions.« less

Fifth Single-Shell Tank Integrity Project Expert Panel Meeting August 28-29, 2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Todd M.; Gunter, Jason R.; Boomer, Kayle D.

On August 28th and 29th, 2014 the Single-Shell Tank Integrity Project (SSTIP) Expert Panel (Panel) convened in Richland, Washington. This was the Panel’s first meeting since 2011 and, as a result, was focused primarily on updating the Panel on progress in response to the past recommendations (Single-Shell Tank Integrity Expert Panel Report, RPP-RPT-45921, Rev 0, May 2010). This letter documents the Panel’s discussions and feedback on Phase I activities and results.

Fabrication of polyacrylate core-shell nanoparticles via spray drying method

NASA Astrophysics Data System (ADS)

Chen, Pengpeng; Cheng, Zenghui; Chu, Fuxiang; Xu, Yuzhi; Wang, Chunpeng

2016-05-01

Fine polyacrylate particles are thought to be environmental plastisols for car industry. However, these particles are mainly dried through demulsification of the latexes, which is not reproducible and hard to be scaled up. In this work, a spray drying method had been applied to the plastisols-used acrylate latex. By adjusting the core/shell ratio, spray drying process of the latex was fully studied. Scanning electronic microscopy observation of the nanoparticles before and after spray drying indicated that the core-shell structures could be well preserved and particles were well separated by spray drying if the shell was thick enough. Otherwise, the particles fused into each other and core-shell structures were destroyed. Polyacrylate plastisols were developed using diisononylphthalate as a plasticizer, and plastigels were obtained after heat treatment of the sols. Results showed that the shell thickness also had a great influence on the storage stability of the plastisols and mechanical properties of the plastigels.

Quality Changes During Long Term Farmers’ Stock Storage

USDA-ARS?s Scientific Manuscript database

Since 2012, U.S. annual peanut production has increased 44% from an average of 2.6 million MT compared with 1.8 million MT (1997 and 2012). This production increase has resulted in longer storage times between harvest and shelling. A study was conducted to observe the changes in quality of farmers...

Rollable Thin Shell Composite-Material Paraboloidal Mirrors

NASA Technical Reports Server (NTRS)

Meinel, Aden; Meinel, Marjorie; Romeo, Robert

2003-01-01

An experiment and calculation have demonstrated the feasibility of a technique of compact storage of paraboloidal mirrors made of thin composite-material (multiple layers of carbon fiber mats in a polymeric matrix) shells coated with metal for reflectivity. Such mirrors are under consideration as simple, lightweight alternatives to the heavier, more complex mirrors now used in space telescopes. They could also be used on Earth in applications in which gravitational sag of the thin shells can be tolerated. The present technique is essentially the same as that used to store large maps, posters, tapestries, and similar objects: One simply rolls up the mirror to a radius small enough to enable the insertion of the mirror in a protective cylindrical case. Provided that the stress associated with rolling the mirror is not so large as to introduce an appreciable amount of hysteresis, the mirror can be expected to spring back to its original shape, with sufficient precision to perform its intended optical function, when unrolled from storage.

Effects of different storage time on hatching results and some egg quality characteristics of rock partridge (A. graeca) (management and production).

PubMed

Günhan, S; Kirikçi, K

2017-06-01

In this research, partridge eggs were stored during zero to 7, 8 to 14, 15 to 21, 22 to 28, 29 to 35 and 36 to 42 d, respectively. The effect of different egg storage periods on egg protein and moisture rates, mineral contents, and some egg quality and hatching characteristics were investigated. The extension of egg storage times didn't affect the external quality features like shell weight, shell thickness, and albumen rate, but it affected the yolk weight, yolk index, albumen index, and Haugh unit (P < 0.05). Yolk weight was increased and yolk index, albumen index, and Haugh unit values were decreased with the extension of storage time. Different storage times of partridge eggs did not have important effects on the protein rates. Protein and humidity rate of the eggs were 14.21 and 67.64%, respectively. There were some elements such as S, P, Na, K, and Ca, but Al, Cd, Co, Mo, and Pb could not be found in the partridge eggs. There is no effect of the storage time on the mineral content of the egg. Storage time had negative effect on fertility and hatchability after 21 d of storage d, but no effect on hatchability of fertile eggs. As this study showed, partridge eggs are resistant to long storage times, as partridge egg proteins can resist degradation in the optimum storage times. To determine egg degradation, the study should be focused on partridge eggshell features, which are responsible for degradation. As a result of this research, partridge eggs can be stored for 21 d under optimum storage conditions without any negative hatchability results. © 2017 Poultry Science Association Inc.

Effect of modified mold shell on the microstructure and tensile fracture morphology of single-crystal nickel-base superalloy

NASA Astrophysics Data System (ADS)

Xu, Weitai; Zhao, Yutao; Sun, Shaochun; Liu, Manping; Ma, Dexin; Liang, Xiangfeng; Wang, Cunlong; Tao, Ran

2018-04-01

The mold shell used for single-crystal turbine blades preparation was modified from conventional process to fiber reinforcement technology. The wall thickness was decreased by 32.3 percent (pct) than the conventional process. Then these two mold shells were used to produce single crystal samples of nickel-base superalloy in a Bridgman furnace. The local temperature curves were recorded in the process. The results show that the modified mold shell can increase the temperature gradient in the mushy zone than the conventional mold shell. The primary and secondary dendrite arm space were reduced by 8 pct and 12 pct, respectively. Moreover, both the area fraction and mean size of the γ‧/γ eutectic were declined, as well as the dendritic segregation tendency. Therefore it contributed to the lower residual eutectic and micro-porosity in the heat-treated microstructure. Further, fracture surface of the samples made by modified mold shell exhibited smaller facets and more uniform dimples in the size and shape.

Suppressed Blinking and Auger Recombination in Near-Infrared Type-II InP/CdS Nanocrystal Quantum Dots

PubMed Central

Dennis, Allison M.; Mangum, Benjamin D.; Piryatinski, Andrei; Park, Young-Shin; Hannah, Daniel C.; Casson, Joanna L.; Williams, Darrick J.; Schaller, Richard D.; Htoon, Han; Hollingsworth, Jennifer A.

2012-01-01

Non-blinking excitonic emission from near-infrared and type-II nanocrystal quantum dots (NQDs) is reported for the first time. To realize this unusual degree of stability at the single-dot level, novel InP/CdS core/shell NQDs were synthesized for a range of shell thicknesses (~1–11 monolayers of CdS). Ensemble spectroscopy measurements (photoluminescence peak position and radiative lifetimes) and electronic structure calculations established the transition from type-I to type-II band alignment in these heterostructured NQDs. More significantly, single-NQD studies revealed clear evidence for blinking suppression that was not strongly shell-thickness dependent, while photobleaching and biexciton lifetimes trended explicitly with extent of shelling. Specifically, very long biexciton lifetimes—up to >7 ns—were obtained for the thickest-shell structures, indicating dramatic suppression of non-radiative Auger recombination. This new system demonstrates that electronic structure and shell thickness can be employed together to effect control over key single-dot and ensemble NQD photophysical properties. PMID:23030497

Chemical composition of Hanford Tank SY-102

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birnbaum, E.; Agnew, S.; Jarvinen, G.

1993-12-01

The US Department of Energy established the Tank Waste Remediation System (TWRS) to safely manage and dispose of the radioactive waste, both current and future, stored in double-shell and single-shell tanks at the Hanford sites. One major program element in TWRS is pretreatment which was established to process the waste prior to disposal using the Hanford Waste Vitrification Plant. In support of this program, Los Alamos National Laboratory has developed a conceptual process flow sheet which will remediate the entire contents of a selected double-shelled underground waste tank, including supernatant and sludge, into forms that allow storage and final disposalmore » in a safe, cost-effective and environmentally sound manner. The specific tank selected for remediation is 241-SY-102 located in the 200 West Area. As part of the flow sheet development effort, the composition of the tank was defined and documented. This database was built by examining the history of liquid waste transfers to the tank and by performing careful analysis of all of the analytical data that have been gathered during the tank`s lifetime. In order to more completely understand the variances in analytical results, material and charge balances were done to help define the chemistry of the various components in the tank. This methodology of defining the tank composition and the final results are documented in this report.« less

Single hole multi-parameter downhole monitoring of shallow CO2 injection at Maguelone experimental site (Languedoc, France)

NASA Astrophysics Data System (ADS)

Denchik, N.; Pezard, P. A.; Abdoulghafour, H.; Lofi, J.; Neyens, D.; Perroud, H.; Henry, G.; Rolland, B.

2015-12-01

The Maguelone experimental site for shallow subsurface hydrogeophysical monitoring, located along the Mediterranean Lido near Montpellier (Languedoc, France) has proven over the years to provide a unique setup to test gas storage monitoring methods at shallow depth. The presence of two small reservoirs (R1: 13-16 m and R2: 8-9 m) with impermeable boundaries provides an opportunity to study a saline formation for geological storage both in the field and in a laboratory context. This integrated monitoring concept was first applied at Maguelone for characterization of the reservoir state before and during N2 and CO2 injections as part of the MUSTANG FP7 project. Multimethod monitoring was shown to be sensitive to gas storage within a saline reservoir with clear data changes immediately after the beginning of injection. Pressure remains the first indicator of gas storage at ~8-9 m depth in a small permeable unit (gravels/shells) under the Holocene lagoonal sediments. A good correlation is also obtained between the resistivity response and geochemical parameters from pore fluid sampling (pH, minor and major cation concentrations) at this depth. On the basis of previous gas injection experiments, new holes were drilled as part of PANACEA (EC project) in 2014, including an injection hole targeted for injection at 8-9 m depth in the R2 reservoir in order to have gas injection and gas storage at the same depth, a single hole multi-parameter observatory, and a seismic source hole. A total volume of ~48 m3 of CO2 was injected over ~2 hours on December 4, 2014. The injection rate varied from 24 to 30 m3/h, with a well head pressure of 1.8 bars. All downhole monitoring technologies (resistivity, temperature, pressure, SP and seismic measurements) were combined in the single hole observatory. Such device allows monitoring the downhole system before and after injection and the gas migration from the injection hole, helping to characterize the transport mechanism. Decreasing the number of monitoring-measurements and verification (MMV) holes enables a significant decrease of gas leakage risk. This specific monitoring approach is expected to give information about the safety and reliability of CO2 storage operation that guarantees public acceptance.

Assessing the impact of egg sweating on Salmonella Enteritidis penetration into shell eggs.

PubMed

Gradl, Janet A; Curtis, Patricia A; Jones, Deana R; Anderson, Kenneth E

2017-07-01

Salmonella Enteritidis (SE) prevalence in eggs is a major concern to the egg industry. Some research has shown that egg sweating can increase Salmonella penetration into egg contents when refrigerated eggs are moved to a warmer temperature. This occurs when eggs are tempered before wash, to minimize thermal cracks. The effect of egg sweating on SE penetration into shell eggs over a 6 week storage period at 4°C was assessed. A 2 × 2 factorial of SE inoculation and egg sweating was utilized. Treatments included (SES) nalidixic acid (NA)-resistant SE inoculated and sweated, (SENS) NA-resistant SE inoculated and not sweated, (NSES) buffered peptone water (BPW) inoculated and sweated, and (NSENS) BPW inoculated and not sweated. Eggs were inoculated with 108 SE. Eggs formed condensation for approximately 17 min in a 32°C incubator. Shell rinse, shell emulsion, and egg contents were sampled then enumerated and assessed for prevalence of SE over a 6 wk storage period at 4°C. After wk 1, the SENS shell rinse had higher SE counts (0.32 log10 CFU/mL) than the other 3 treatments, where no SE was enumerated. A significant week by treatment interaction was found for the shell rinse SE detection (P < 0.05). In subsequent weeks, no SE counts were obtained from the egg shell rinse, shell emulsion, or egg contents. The SENS shell rinses had significantly higher SE prevalence than the SES rinses in weeks 1 (100% vs. 34.3%), 2 (57.6% vs. 22.2%), and 3 (38.2% vs. 11.1%) (P < 0.05). In samples from weeks 4, 5, and 6, there was no difference in SE prevalence between SES and SENS. Egg sweating did not increase SE penetration into the shell emulsion across treatment or week (P < 0.05). The decreasing trend of SE prevalence obtained over the study period indicate that refrigeration is effective at inhibiting SE growth. These results indicate that egg sweating occurring under common US egg handling practices is not harmful to egg safety. © 2017 Poultry Science Association Inc.

Single-mode tunable laser emission in the single-exciton regime from colloidal nanocrystals

PubMed Central

Grivas, Christos; Li, Chunyong; Andreakou, Peristera; Wang, Pengfei; Ding, Ming; Brambilla, Gilberto; Manna, Liberato; Lagoudakis, Pavlos

2013-01-01

Whispering-gallery-mode resonators have been extensively used in conjunction with different materials for the development of a variety of photonic devices. Among the latter, hybrid structures, consisting of dielectric microspheres and colloidal core/shell semiconductor nanocrystals as gain media, have attracted interest for the development of microlasers and studies of cavity quantum electrodynamic effects. Here we demonstrate single-exciton, single-mode, spectrally tuned lasing from ensembles of optical antenna-designed, colloidal core/shell CdSe/CdS quantum rods deposited on silica microspheres. We obtain single-exciton emission by capitalizing on the band structure of the specific core/shell architecture that strongly localizes holes in the core, and the two-dimensional quantum confinement of electrons across the elongated shell. This creates a type-II conduction band alignment driven by coulombic repulsion that eliminates non-radiative multi-exciton Auger recombination processes, thereby inducing a large exciton–bi-exciton energy shift. Their ultra-low thresholds and single-mode, single-exciton emission make these hybrid lasers appealing for various applications, including quantum information processing. PMID:23974520

Sound Transmission through Two Concentric Cylindrical Sandwich Shells

NASA Technical Reports Server (NTRS)

Tang, Yvette Y.; Silcox, Richard J.; Robinson, Jay H.

1996-01-01

This paper solves the problem of sound transmission through a system of two infinite concentric cylindrical sandwich shells. The shells are surrounded by external and internal fluid media and there is fluid (air) in the annular space between them. An oblique plane sound wave is incident upon the surface of the outer shell. A uniform flow is moving with a constant velocity in the external fluid medium. Classical thin shell theory is applied to the inner shell and first-order shear deformation theory is applied to the outer shell. A closed form for transmission loss is derived based on modal analysis. Investigations have been made for the impedance of both shells and the transmission loss through the shells from the exterior into the interior. Results are compared for double sandwich shells and single sandwich shells. This study shows that: (1) the impedance of the inner shell is much smaller than that of the outer shell so that the transmission loss is almost the same in both the annular space and the interior cavity of the shells; (2) the two concentric sandwich shells can produce an appreciable increase of transmission loss over single sandwich shells especially in the high frequency range; and (3) design guidelines may be derived with respect to the noise reduction requirement and the pressure in the annular space at a mid-frequency range.

Overview of Hanford Single Shell Tank (SST) Structural Integrity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rast, Richard S.; Washenfelder, Dennis J.; Johnson, Jeremy M.

2013-11-14

To improve the understanding of the single-shell tanks (SSTs) integrity, Washington River Protection Solutions, LLC (WRPS), the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank Integrity Project (SSTIP) in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration, Seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for themore » Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement. The structural integrity of the tanks is a key element in completing the cleanup mission at the Hanford Site. There are eight primary recommendations related to the structural integrity of Hanford Single-Shell Tanks. Six recommendations are being implemented through current and planned activities. The structural integrity of the Hanford is being evaluated through analysis, monitoring, inspection, materials testing, and construction document review. Structural evaluation in the form of analysis is performed using modern finite element models generated in ANSYS. The analyses consider in-situ, thermal, operating loads and natural phenomena such as earthquakes. Structural analysis of 108 of 149 Hanford Single-Shell Tanks has concluded that the tanks are structurally sound and meet current industry standards. Analysis of the remaining Hanford Single-Shell Tanks is scheduled for FY2014. Hanford Single-Shell Tanks are monitored through a dome deflection program. The program looks for deflections of the tank dome greater than 1/4 inch. No such deflections have been recorded. The tanks are also subjected to visual inspection. Digital cameras record the interior surface of the concrete tanks, looking for cracks and other surface conditions that may indicate signs of structural distress. The condition of the concrete and rebar of the Hanford Single-Shell Tanks is currently being tested and planned for additional activities in the near future. Concrete and rebar removed from the dome of a 65 year old tank was tested for mechanics properties and condition. Results indicated stronger than designed concrete with additional Petrographic examination and rebar completed. Material properties determined from previous efforts combined with current testing and construction document review will help to generate a database that will provide indication of Hanford Single-Shell Tank structural integrity.« less

Refinery Capacity Report

EIA Publications

2017-01-01

Data series include fuel, electricity, and steam purchased for consumption at the refinery; refinery receipts of crude oil by method of transportation; and current and projected atmospheric crude oil distillation, downstream charge, and production capacities. Respondents are operators of all operating and idle petroleum refineries (including new refineries under construction) and refineries shut down during the previous year, located in the 50 states, the District of Columbia, Puerto Rico, the Virgin Islands, Guam, and other U.S. possessions. The Refinery Capacity Report does not contain working and shell storage capacity data. This data is now being collected twice a year as of March 31 and September 30 on the Form EIA-810, "Monthly Refinery Report", and is now released as a separate report Working and Net Available Shell Storage Capacity.

76 FR 67675 - Notice of Preliminary Determination of Sales at Less Than Fair Value, Postponement of Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-02

... storage compartments accessible through one or more separate external doors or drawers or a combination thereof; An upper-most interior storage compartment(s) that is accessible through an external door or... external metal shell, (b) a back panel, (c) a deck, (d) an interior plastic liner, (e) wiring, and (f...

Storage-based Intrusion Detection: Watching storage activity for suspicious behavior

DTIC Science & Technology

2002-10-01

password management involves a pair of inter-related files (/etc/ passwd and /etc/shadow). The corresponding access pat- terns seen at the storage...example, consider a UNIX system password file (/etc/ passwd ), which con- sists of a set of well-defined records. Records are delimited by a line-break, and...etc/ passwd and verify that they conform to a set of basic integrity rules: 7-field records, non-empty password field, legal default shell, legal home

Effects of ionic and nonionic surfactants on milk shell wettability during co-spray-drying of whole milk particles.

PubMed

Lallbeeharry, P; Tian, Y; Fu, N; Wu, W D; Woo, M W; Selomulya, C; Chen, X D

2014-09-01

Mixing surfactants with whole milk feed before spray drying could be a commercially favorable approach to produce instant whole milk powders in a single step. Pure whole milk powders obtained directly from spray drying often have a high surface fat coverage (up to 98%), rendering them less stable during storage and less wettable upon reconstitution. Dairy industries often coat these powders with lecithin, a food-grade surfactant, in a secondary fluidized-bed drying stage to produce instant powders. This study investigated the changes in wetting behavior on the surface of a whole milk particle caused by the addition of surfactants before drying. Fresh whole milk was mixed with 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin (total solids), and the wetting behavior of the shell formed by each sample was captured using a single-droplet drying device at intermediate drying stages as the shell was forming. The addition of surfactants improved shell wettability from the beginning of shell formation, producing more wettable milk particles after drying. The increase in surfactant loading by 10 times reduced the wetting time from around 30s to <5s. At the same loading of 1% (wt/wt; total solids), milk particles with Tween 80 were much more wettable than those with lecithin (<5s compared with >30s). We proposed that Tween 80 could adsorb at the oil-water interface of fat globules, making the surface fat more wettable, whereas lecithin tends to combine with milk proteins to form a complex, which then competes for the air-water surface with fat globules. Spray-drying experiments confirmed the greatly improved wettability of whole milk powders by the addition of either 0.1% (wt/wt) Tween 80 or 1% (wt/wt) lecithin; wetting time was reduced from 35±4s to <15s. To the best of our knowledge, this is the first time that a dynamic droplet drying system has been used to elucidate the complex interactions between ionic or nonionic surfactants and milk components (both proteins and fat), as well as the resultant effect on the development of milk particle functionality during drying. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

A microbial spoilage profile of half shell Pacific oysters (Crassostrea gigas) and Sydney rock oysters (Saccostrea glomerata).

PubMed

Madigan, Thomas L; Bott, Nathan J; Torok, Valeria A; Percy, Nigel J; Carragher, John F; de Barros Lopes, Miguel A; Kiermeier, Andreas

2014-04-01

This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters. Copyright © 2013 Elsevier Ltd. All rights reserved.

Comprehensive analyses of core-shell InGaN/GaN single nanowire photodiodes

NASA Astrophysics Data System (ADS)

Zhang, H.; Guan, N.; Piazza, V.; Kapoor, A.; Bougerol, C.; Julien, F. H.; Babichev, A. V.; Cavassilas, N.; Bescond, M.; Michelini, F.; Foldyna, M.; Gautier, E.; Durand, C.; Eymery, J.; Tchernycheva, M.

2017-12-01

Single nitride nanowire core/shell n-p photodetectors are fabricated and analyzed. Nanowires consisting of an n-doped GaN stem, a radial InGaN/GaN multiple quantum well system and a p-doped GaN external shell were grown by catalyst-free metal-organic vapour phase epitaxy on sapphire substrates. Single nanowires were dispersed and the core and the shell regions were contacted with a metal and an ITO deposition, respectively, defined using electron beam lithography. The single wire photodiodes present a response in the visible to UV spectral range under zero external bias. The detector operation speed has been analyzed under different bias conditions. Under zero bias, the  -3 dB cut-off frequency is ~200 Hz for small light modulations. The current generation was modeled using non-equilibrium Green function formalism, which evidenced the importance of phonon scattering for carrier extraction from the quantum wells.

Do encapsulated heat storage materials really retain their original thermal properties?

PubMed

Chaiyasat, Preeyaporn; Noppalit, Sayrung; Okubo, Masayoshi; Chaiyasat, Amorn

2015-01-14

The encapsulation of Rubitherm®27 (RT27), which is one of the most common commercially supplied heat storage materials, by polystyrene (PS), polydivinyl benzene (PDVB) and polymethyl methacrylate (PMMA) was carried out using conventional radical microsuspension polymerization. The products were purified to remove free RT27 and free polymer particles without RT27. In the cases of PS and PDVB microcapsules, the latent heats of melting and crystallization for RT27 ( and , J/g-RT27) were clearly decreased by the encapsulation. On the other hand, those of the PMMA microcapsules were the same as pure RT27. A supercooling phenomenon was observed not only for PS and PDVB but also for the PMMA microcapsules. These results indicate that the thermal properties of the heat storage materials encapsulated depend on the type of polymer shells, i.e., encapsulation by polymer shell changes the thermal properties of RT27. This is quite different from the idea of other groups in the world, in which they discussed the thermal properties based on the ΔHm and ΔHc values expressed in J/g-capsule, assuming that the thermal properties of the heat storage materials are not changed by the encapsulation. Hereafter, this report should raise an alarm concerning the "wrong" common knowledge behind developing the encapsulation technology of heat storage materials.

Fabrication of CuO-Pt core-shell nanohooks by in situ reconstructing the Pt-shells.

PubMed

Cao, Fan; Zheng, He; Zhao, Ligong; Huang, Rui; Jia, Shuangfeng; Liu, Huihui; Li, Lei; Wang, Zhao; Hu, Yongming; Gu, Haoshuang; Wang, Jianbo

2018-05-25

The design of various nanostructures with specific compositions and shapes is highly demanded due to the widespread use of micro/nano electro-mechanical systems. In this work, one-dimensional CuO-Pt core-shell nanowires (NWs) are acquired by depositing Pt nanoparticles onto CuO NWs and then mechanically-shaped into nanohooks. Subsequently, the hook-like shape is maintained by the Pt-shell which is reconstructed via Joule heat and re-solidified after cooling down, during which the elastic strain energy is stored in the CuO-core. The results provide a simple strategy to design nanostructures with various compositions and shapes, implying the potential applications in mechanical energy storage and shape memory nanodevices.

Fabrication of CuO–Pt core–shell nanohooks by in situ reconstructing the Pt-shells

NASA Astrophysics Data System (ADS)

Cao, Fan; Zheng, He; Zhao, Ligong; Huang, Rui; Jia, Shuangfeng; Liu, Huihui; Li, Lei; Wang, Zhao; Hu, Yongming; Gu, Haoshuang; Wang, Jianbo

2018-05-01

The design of various nanostructures with specific compositions and shapes is highly demanded due to the widespread use of micro/nano electro-mechanical systems. In this work, one-dimensional CuO–Pt core–shell nanowires (NWs) are acquired by depositing Pt nanoparticles onto CuO NWs and then mechanically-shaped into nanohooks. Subsequently, the hook-like shape is maintained by the Pt-shell which is reconstructed via Joule heat and re-solidified after cooling down, during which the elastic strain energy is stored in the CuO-core. The results provide a simple strategy to design nanostructures with various compositions and shapes, implying the potential applications in mechanical energy storage and shape memory nanodevices.

Effect of ultrasonic treatment on reduction of Esherichia coli ATCC 25922 and egg quality parameters in experimentally contaminated hens' shell eggs.

PubMed

Sert, Durmus; Aygun, Ali; Torlak, Emrah; Mercan, Emin

2013-09-01

In this study, hen eggs which were experimentally contaminated with Esherichia coli ATCC 25922 were used. Contaminated eggs were washed statically (S5 to S30; 0 kHz) and by ultrasonic waves (U5 to U30; 35 kHz) for given applications of time (5, 15 and 30 min), then the eggs were stored at 22°C for 14 days. Depending on the time of ultrasonic application, a significant increase in egg shell strength (P < 0.01) was recorded. The highest value of the Haugh unit (67.93, 1 day) was observed on the eggs which were washed by ultrasonic waves. Yolk width values of ultrasonic washed eggs diminished. E. coli was completely removed by 30 min of ultrasonic application. During storage E. coli growth was not detected on the eggs which were washed by ultrasonic waves except the eggs in U5 group (2.04 log CFU eggshell⁻¹) on the first day of storage. Depending on the time of ultrasonic application a significant increase in egg quality parameters (shell strength, albumen height, Haugh units, and yolk height) were observed. The application of ultrasound led to a significant reduction in E. coli numbers on egg shells. © 2013 Society of Chemical Industry.

Self-template synthesis of double shelled ZnS-NiS1.97 hollow spheres for electrochemical energy storage

NASA Astrophysics Data System (ADS)

Wei, Chengzhen; Ru, Qinglong; Kang, Xiaoting; Hou, Haiyan; Cheng, Cheng; Zhang, Daojun

2018-03-01

In this work, double shelled ZnS-NiS1.97 hollow spheres have been achieved via a simple self-template route, which involves the synthesis of Zn-Ni solid spheres precursors as the self-template and then transformation into double shelled ZnS-NiS1.97 hollow spheres by sulfidation treatment. The as-prepared double shelled ZnS-NiS1.97 hollow spheres possess a high surface area (105.26 m2 g-1) and porous structures. Benefiting from the combined characteristics of novel structures, multi-component, high surface area and porous. When applied as electrode materials for supercapacitors, the double shelled ZnS-NiS1.97hollow spheres deliver a large specific capacitance of 696.8C g-1 at 5.0 A g-1 and a remarkable long lifespan cycling stability (less 5.5% loss after 6000 cycles). Moreover, an asymmetric supercapacitor (ASC) was assembled by utilizing ZnS-NiS1.97 (positive electrode) and activated carbon (negative electrode) as electrode materials. The as-assembled device possesses an energy density of 36 W h kg-1, which can be yet retained 25.6 W h kg-1 even at a power density of 2173.8 W Kg-1, indicating its promising applications in electrochemical energy storage. More importantly, the self-template route is a simple and versatile strategy for the preparation of metal sulfides electrode materials with desired structures, chemical compositions and electrochemical performances.

Structural characterization of encapsulated ferritin provides insight into iron storage in bacterial nanocompartments

PubMed Central

He, Didi; Hughes, Sam; Vanden-Hehir, Sally; Georgiev, Atanas; Altenbach, Kirsten; Tarrant, Emma; Mackay, C Logan; Waldron, Kevin J; Clarke, David J; Marles-Wright, Jon

2016-01-01

Ferritins are ubiquitous proteins that oxidise and store iron within a protein shell to protect cells from oxidative damage. We have characterized the structure and function of a new member of the ferritin superfamily that is sequestered within an encapsulin capsid. We show that this encapsulated ferritin (EncFtn) has two main alpha helices, which assemble in a metal dependent manner to form a ferroxidase center at a dimer interface. EncFtn adopts an open decameric structure that is topologically distinct from other ferritins. While EncFtn acts as a ferroxidase, it cannot mineralize iron. Conversely, the encapsulin shell associates with iron, but is not enzymatically active, and we demonstrate that EncFtn must be housed within the encapsulin for iron storage. This encapsulin nanocompartment is widely distributed in bacteria and archaea and represents a distinct class of iron storage system, where the oxidation and mineralization of iron are distributed between two proteins. DOI: http://dx.doi.org/10.7554/eLife.18972.001 PMID:27529188

NESC Review of the 8-Foot High Temperature Tunnel (HTT) Oxygen Storage Pressure Vessel Inspection Requirements

NASA Technical Reports Server (NTRS)

Gilbert, Michael; Raju, Ivatury; Piascik, Robert; Cameron, Kenneth; Kirsch, Michael; Hoffman, Eric; Murthy, Pappu; Hopson, George; Greulich, Owen; Frazier, Wayne

2009-01-01

The 8-Foot HTT (refer to Figure 4.0-1) is used to conduct tests of air-breathing hypersonic propulsion systems at Mach numbers 4, 5, and 7. Methane, Air, and LOX are mixed and burned in a combustor to produce test gas stream containing 21 percent by volume oxygen. The NESC was requested by the NASA LaRC Executive Safety Council to review the rationale for a proposed change to the recertification requirements, specifically the internal inspection requirements, of the 8-Foot HTT LOX Run Tank and LOX Storage Tank. The Run Tank is an 8,000 gallon cryogenic tank used to provide LOX to the tunnel during operations, and is pressured during the tunnel run to 2,250 pounds per square inch gage (psig). The Storage Tank is a 25,000 gallon cryogenic tank used to store LOX at slightly above atmospheric pressure as a external shell, with space between the shells maintained under vacuum conditions.

From J. J. Thomson to FAIR, what do we learn from Large-Scale Mass and Half-Life Measurements of Bare and Few-Electron Ions?

NASA Astrophysics Data System (ADS)

Münzenberg, Gottfried; Geissel, Hans; Litvinov, Yuri A.

2010-04-01

This contribution is based on the combination of the talks: "What can we learn from large-scale mass measurements," "Present and future experiments with stored exotic nuclei at relativistic energies," and "Beta decay of highly-charged ions." Studying the nuclear mass surface gives information on the evolution of nuclear structure such as nuclear shells, the onset of deformation and the drip-lines. Previously, most of the masses far-off stability has been obtained from decay data. Modern methods allow direct mass measurements. They are much more sensitive, down to single atoms, access short-lived species and have high accuracy. Large-scale explorations of the nuclear mass surface are ideally performed with the combination of the in-flight FRagment Separator FRS and the Experimental Storage Ring ESR. After a brief historic introduction selected examples such as the evolution of shell closures far-off stability and the proton-neutron interaction will be discussed in the framework of our data. Recently, the experiments have been extended and led to the discovery of new heavy neutron-rich isotopes along with their mass and lifetime measurements. Storage rings applied at relativistic energies are a unique tool to study the radioactive decay of bare or few-electron atomic nuclei. New features observed with the analysis of stored circulating mother and daughter ions including oscillations in the decay curves of hydrogen-like nuclei will be addressed. Future experiments with NUSTAR at FAIR will further extend our knowledge to the borderlines of nuclear existence.

DEVELOPMENT AND DEPLOYMENT OF THE MOBILE ARM RETRIEVAL SYSTEM (MARS) - 12187

DOE Office of Scientific and Technical Information (OSTI.GOV)

BURKE CA; LANDON MR; HANSON CE

Washington River Protection Solutions (WRPS) is developing and deploying Mobile Arm Retrieval System (MARS) technologies solutions to support retrieval of radioactive and chemical waste from underground single shell storage tanks (SST) located at the Hanford Site, which is near Richland, Washington. WRPS has developed the MARS using a standardized platform that is capable of deploying multiple retrieval technologies. To date, WRPS, working with their mentor-protege company, Columbia Energy and Environmental Services (CEES), has developed two retrieval mechanisms, MARS-Sluicing (MARS-S) and MARS-Vacuum (MARS-V). MARS-S uses pressurized fluids routed through spray nozzles to mobilize waste materials to a centrally located slurry pumpmore » (deployed in 2011). MARS-V uses pressurized fluids routed through an eductor nozzle. The eductor nozzle allows a vacuum to be drawn on the waste materials. The vacuum allows the waste materials to be moved to an in-tank vessel, then extracted from the SST and subsequently pumped to newer and safer double shell tanks (DST) for storage until the waste is treated for disposal. The MARS-S system is targeted for sound SSTs (i.e., non leaking tanks). The MARS-V is targeted for assumed leaking tanks or those tanks that are of questionable integrity. Both versions of MARS are beinglhave been developed in compliance with WRPS's TFC-PLN-90, Technology Development Management Plan [1]. TFC-PLN-90 includes a phased approach to design, testing, and ultimate deployment of new technologies. The MARS-V is scheduled to be deployed in tank 241-C-105 in late 2012.« less

Development and Deployment of the Mobile Arm Retrieval System (MARS) - 12187

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burke, Christopher A.; Landon, Matthew R.; Hanson, Carl E.

Washington River Protection Solutions (WRPS) is developing and deploying Mobile Arm Retrieval System (MARS) technologies solutions to support retrieval of radioactive and chemical waste from underground single shell storage tanks (SST) located at the Hanford Site, which is near Richland, Washington. WRPS has developed the MARS using a standardized platform that is capable of deploying multiple retrieval technologies. To date, WRPS, working with their mentor-protege company, Columbia Energy and Environmental Services (CEES), has developed two retrieval mechanisms, MARS-Sluicing (MARS-S) and MARS-Vacuum (MARS-V). MARS-S uses pressurized fluids routed through spray nozzles to mobilize waste materials to a centrally located slurry pumpmore » (deployed in 2011). MARS-V uses pressurized fluids routed through an eductor nozzle. The eductor nozzle allows a vacuum to be drawn on the waste materials. The vacuum allows the waste materials to be moved to an in-tank vessel, then extracted from the SST and subsequently pumped to newer and safer double shell tanks (DST) for storage until the waste is treated for disposal. The MARS-S system is targeted for sound SSTs (i.e., non leaking tanks). The MARS-V is targeted for assumed leaking tanks or those tanks that are of questionable integrity. Both versions of MARS are being/have been developed in compliance with WRPS's TFC-PLN-90, Technology Development Management Plan [1]. TFC-PLN-90 includes a phased approach to design, testing, and ultimate deployment of new technologies. The MARS-V is scheduled to be deployed in tank 241-C-105 in late 2012. (authors)« less

DEVELOPMENT AND DEPLOYMENT OF THE MOBILE ARM RETRIEVAL SYSTEM (MARS) - 12187

DOE Office of Scientific and Technical Information (OSTI.GOV)

BURKE CA; LANDON MR; HANSON CE

Washington River Protection Solutions (WRPS) is developing and deploying Mobile Arm Retrieval System (MARS) technologies solutions to support retrieval of radioactive and chemical waste from underground single shell storage tanks (SST) located at the Hanford Site, which is near Richland, Washington. WRPS has developed the MARS using a standardized platform that is capable of deploying multiple retrieval technologies. To date, WRPS, working with their mentor-protege company, Columbia Energy and Environmental Services (CEES), has developed two retrieval mechanisms, MARS-Sluicing (MARS-S) and MARS-Vacuum (MARS-V). MARS-S uses pressurized fluids routed through spray nozzles to mobilize waste materials to a centrally located slurry pumpmore » (deployed in 2011). MARS-V uses pressurized fluids routed through an eductor nozzle. The eductor nozzle allows a vacuum to be drawn on the waste materials. The vacuum allows the waste materials to be moved to an in-tank vessel, then extracted from the SST and subsequently pumped to newer and safer double shell tanks (DST) for storage until the waste is treated for disposal. The MARS-S system is targeted for sound SSTs (i.e., non leaking tanks). The MARS-V is targeted for assumed leaking tanks or those tanks that are of questionable integrity. Both versions of MARS are being/have been developed in compliance with WRPS's TFC-PLN-90, Technology Development Management Plan. TFC-PLN-90 includes a phased approach to design, testing, and ultimate deployment of new technologies. The MARS-V is scheduled to be deployed in tank 241-C-105 in late 2012.« less

Heat transfer and thermal management of electric vehicle batteries with phase change materials

NASA Astrophysics Data System (ADS)

Ramandi, M. Y.; Dincer, I.; Naterer, G. F.

2011-07-01

This paper examines a passive thermal management system for electric vehicle batteries, consisting of encapsulated phase change material (PCM) which melts during a process to absorb the heat generated by a battery. A new configuration for the thermal management system, using double series PCM shells, is analyzed with finite volume simulations. A combination of computational fluid dynamics (CFD) and second law analysis is used to evaluate and compare the new system against the single PCM shells. Using a finite volume method, heat transfer in the battery pack is examined and the results are used to analyse the exergy losses. The simulations provide design guidelines for the thermal management system to minimize the size and cost of the system. The thermal conductivity and melting temperature are studied as two important parameters in the configuration of the shells. Heat transfer from the surroundings to the PCM shell in a non-insulated case is found to be infeasible. For a single PCM system, the exergy efficiency is below 50%. For the second case for other combinations, the exergy efficiencies ranged from 30-40%. The second shell content did not have significant influence on the exergy efficiencies. The double PCM shell system showed higher exergy efficiencies than the single PCM shell system (except a case for type PCM-1). With respect to the reference environment, it is found that in all cases the exergy efficiencies decreased, when the dead-state temperatures rises, and the destroyed exergy content increases gradually. For the double shell systems for all dead-state temperatures, the efficiencies were very similar. Except for a dead-state temperature of 302 K, with the other temperatures, the exergy efficiencies for different combinations are well over 50%. The range of exergy efficiencies vary widely between 15 and 85% for a single shell system, and between 30-80% for double shell systems.

Magnetically controlled multifrequency invisibility cloak with a single shell of ferrite material

NASA Astrophysics Data System (ADS)

Wang, Xiaohua; Liu, Youwen

2015-02-01

A magnetically controlled multifrequency invisibility cloak with a single shell of the isotropic and homogeneous ferrite material has been investigated based on the scattering cancellation method from the Mie scattering theory. The analytical and simulated results have demonstrated that such this shell can drastically reduce the total scattering cross-section of this cloaking system at multiple frequencies. These multiple cloaking frequencies of this shell can be externally controlled since the magnetic permeability of ferrites is well tuned by the applied magnetic field. This may provide a potential way to design a tunable multifrequency invisibility cloak with considerable flexibility.

Characterization of core–shell MOF particles by depth profiling experiments using on-line single particle mass spectrometry

DOE PAGES

Cahill, J. F.; Fei, H.; Cohen, S. M.; ...

2015-01-05

Materials with core-shell structures have distinct properties that lend themselves to a variety of potential applications. Characterization of small particle core-shell materials presents a unique analytical challenge. Herein, single particles of solid-state materials with core-shell structures were measured using on-line aerosol time-of-flight mass spectrometry (ATOFMS). Laser 'depth profiling' experiments verified the core-shell nature of two known core-shell particle configurations (< 2 mu m diameter) that possessed inverted, complimentary core-shell compositions (ZrO2@SiO2 versus SiO2@ZrO2). The average peak area ratios of Si and Zr ions were calculated to definitively show their core-shell composition. These ratio curves acted as a calibrant for anmore » uncharacterized sample - a metal-organic framework (MOF) material surround by silica (UiO-66(Zr)@SiO2; UiO = University of Oslo). ATOFMS depth profiling was used to show that these particles did indeed exhibit a core-shell architecture. The results presented here show that ATOFMS can provide unique insights into core-shell solid-state materials with particle diameters between 0.2-3 mu m.« less

Triggered high-purity telecom-wavelength single-photon generation from p-shell-driven InGaAs/GaAs quantum dot.

PubMed

Dusanowski, Ł; Holewa, P; Maryński, A; Musiał, A; Heuser, T; Srocka, N; Quandt, D; Strittmatter, A; Rodt, S; Misiewicz, J; Reitzenstein, S; Sęk, G

2017-12-11

We report on the experimental demonstration of triggered single-photon emission at the telecom O-band from In(Ga)As/GaAs quantum dots (QDs) grown by metal-organic vapor-phase epitaxy. Micro-photoluminescence excitation experiments allowed us to identify the p-shell excitonic states in agreement with high excitation photoluminescence on the ensemble of QDs. Hereby we drive an O-band-emitting GaAs-based QD into the p-shell states to get a triggered single photon source of high purity. Applying pulsed p-shell resonant excitation results in strong suppression of multiphoton events evidenced by the as measured value of the second-order correlation function at zero delay of 0.03 (and ~0.005 after background correction).

Nano-engineering of three-dimensional core/shell nanotube arrays for high performance supercapacitors

NASA Astrophysics Data System (ADS)

Grote, Fabian; Wen, Liaoyong; Lei, Yong

2014-06-01

Large-scale arrays of core/shell nanostructures are highly desirable to enhance the performance of supercapacitors. Here we demonstrate an innovative template-based fabrication technique with high structural controllability, which is capable of synthesizing well-ordered three-dimensional arrays of SnO2/MnO2 core/shell nanotubes for electrochemical energy storage in supercapacitor applications. The SnO2 core is fabricated by atomic layer deposition and provides a highly electrical conductive matrix. Subsequently a thin MnO2 shell is coated by electrochemical deposition onto the SnO2 core, which guarantees a short ion diffusion length within the shell. The core/shell structure shows an excellent electrochemical performance with a high specific capacitance of 910 F g-1 at 1 A g-1 and a good rate capability of remaining 217 F g-1 at 50 A g-1. These results shall pave the way to realize aqueous based asymmetric supercapacitors with high specific power and high specific energy.

Carbon-silicon core-shell nanowires as high capacity electrode for lithium ion batteries.

PubMed

Cui, Li-Feng; Yang, Yuan; Hsu, Ching-Mei; Cui, Yi

2009-09-01

We introduce a novel design of carbon-silicon core-shell nanowires for high power and long life lithium battery electrodes. Amorphous silicon was coated onto carbon nanofibers to form a core-shell structure and the resulted core-shell nanowires showed great performance as anode material. Since carbon has a much smaller capacity compared to silicon, the carbon core experiences less structural stress or damage during lithium cycling and can function as a mechanical support and an efficient electron conducting pathway. These nanowires have a high charge storage capacity of approximately 2000 mAh/g and good cycling life. They also have a high Coulmbic efficiency of 90% for the first cycle and 98-99.6% for the following cycles. A full cell composed of LiCoO(2) cathode and carbon-silicon core-shell nanowire anode is also demonstrated. Significantly, using these core-shell nanowires we have obtained high mass loading and an area capacity of approximately 4 mAh/cm(2), which is comparable to commercial battery values.

Chemical Structure, Ensemble and Single-Particle Spectroscopy of Thick-Shell InP-ZnSe Quantum Dots.

PubMed

Reid, Kemar R; McBride, James R; Freymeyer, Nathaniel J; Thal, Lucas B; Rosenthal, Sandra J

2018-02-14

Thick-shell (>5 nm) InP-ZnSe colloidal quantum dots (QDs) grown by a continuous-injection shell growth process are reported. The growth of a thick crystalline shell is attributed to the high temperature of the growth process and the relatively low lattice mismatch between the InP core and ZnSe shell. In addition to a narrow ensemble photoluminescence (PL) line-width (∼40 nm), ensemble and single-particle emission dynamics measurements indicate that blinking and Auger recombination are reduced in these heterostructures. More specifically, high single-dot ON-times (>95%) were obtained for the core-shell QDs, and measured ensemble biexciton lifetimes, τ 2x ∼ 540 ps, represent a 7-fold increase compared to InP-ZnS QDs. Further, high-resolution energy dispersive X-ray (EDX) chemical maps directly show for the first time significant incorporation of indium into the shell of the InP-ZnSe QDs. Examination of the atomic structure of the thick-shell QDs by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) reveals structural defects in subpopulations of particles that may mitigate PL efficiencies (∼40% in ensemble), providing insight toward further synthetic refinement. These InP-ZnSe heterostructures represent progress toward fully cadmium-free QDs with superior photophysical properties important in biological labeling and other emission-based technologies.

Test procedures and instructions for single shell tank saltcake cesium removal with crystalline silicotitanate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duncan, J.B.

1997-01-07

This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test, using Hanford Single Shell Tank Saltcake from tanks 24 t -BY- I 10, 24 1 -U- 108, 24 1 -U- 109, 24 1 -A- I 0 1, and 24 t - S-102, in a bench-scale column. The cesium sorbent to be tested is crystalline siticotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-024, Hanford Single Shell Tank Saltcake Cesium Removal Test Plan.

Double-shell CuS nanocages as advanced supercapacitor electrode materials

NASA Astrophysics Data System (ADS)

Guo, Jinxue; Zhang, Xinqun; Sun, Yanfang; Zhang, Xiaohong; Tang, Lin; Zhang, Xiao

2017-07-01

Metal sulfides hollow structures are advanced materials for energy storage applications of lithium-ion batteries and supercapacitors. However, constructing hollow metal sulfides with specific features, such as multi-shell and non-spherical shape, still remains great challenge. In this work, we firstly demonstrate the synthesis of CuS double-shell hollow nanocages using Cu2O nanocubes as precursors. The synthesis processes involve the repeated anion exchange reaction with Na2S and the controllable etching using hydrochloric acid. The whole synthesis processes are well revealed and the obtained double-shell CuS is tested as pseudocapacitive electrode material for supercapacitors. As expected, the CuS double-shell hollow nanocages deliver high specific capacitance, good rate performance and excellent cycling stability due to their unique nano-architecture. The present work contributes greatly to the exploration of hollow metal sulfides with complex architecture and non-spherical shape, as well as their promising application in high-performance electrochemical supercapacitors.

Ultra-strong surface plasmon amplification characteristic of a spaser based on gold-silver core-shell nanorods

NASA Astrophysics Data System (ADS)

Zhang, Li; Zhou, Jun; Zhang, Haopeng; Jiang, Tao; Lou, Cibo

2015-03-01

We proposed an efficient spaser based on gold-silver core-shell nanorods (NRs) encapsulated by an outer silica shell doped with a gain medium. The optical characteristics of the spaser were numerically simulated based on the finite element method (FEM). The results showed that the localized surface plasmon resonance (LSPR) amplification characteristics of the spaser strongly depend on the thickness of silver shell, the aspect ratio of the inner gold NRs, and the polarization direction of the incident light. And, the maximum absolute value of optical cross-section of the spaser can reach 21,824 μm2, which is about 1115, 523, and 18 times higher than that of spasers based on the gold NRs, the silver NRs, and the silver-gold core-shell NRs, respectively. The ultra-strong surface plasmon amplification characteristics of the spaser have potential applications in optical information storage, high sensitivity biochemical sensing, and medical engineering.

Effects of Substerilization Doses of Co60 Gamma Radiation on the Cold-Storage Life Extension of Shucked Soft-Shelled Clams and Haddock Fillets

PubMed Central

Masurovsky, E. B.; Goldblith, S. A.; Nickerson, J. T. R.

1963-01-01

Total aerobic-facultative and anaerobic (clostridia) macrocolony count data are presented, with analysis and interpretation, for both haddock fillets and shucked soft-shelled clams which received doses of from 50,000 to 800,000 rad of Co60 gamma rays. These data indicated that haddock fillets may be maintained in good condition at refrigeration temperatures above freezing for about 1 week at 6 C, and approximately 2 weeks at 0 C, when treated with from 50,000 to 150,000 rad of ionizing radiation. In the dose range from 200,000 to 350,000 rad, the storage life may be extended up to some 2 weeks at 6 C, and 3 weeks at 0 C. Treatments in the dose range from 400,000 to 500,000 rad may defer spoilage for about 1 month, and doses of 550,000 to 650,000 rad afford protection against bacterial spoilage up to approximately 1.5 months. At the high substerilization doses of 700,000 to 800,000 rad, haddock fillets may be held for from 2 to 3 months in refrigerated storage before becoming unfit for marketing and consumption. Shucked soft-shelled clams can be held for about 2.5 weeks at 0 C and close to 12 days at 6 C, when given low substerilization doses of from 50,000 to 150,000 rad of ionizing radiation. At doses of from 200,000 to 350,000 rad, the clams may be preserved effectively for periods up to 3 weeks at 0 or 6 C, and some 6 weeks at these temperatures with doses of about 450,000 rad. With treatments of 500,000 to 600,000 rad, the storage life may be extended for some 2 months, and at doses of 650,000 to 800,000 rad the shucked clams remain in a good state of preservation for up to 3 months at temperatures of 0 to 6 C. Thus, it would appear that shucked soft-shelled clams may be maintained for significantly longer periods in refrigerated storage than haddock fillets when the same radiation treatments are applied to each product. Clostridia levels in both products were relatively low initially, and were reduced significantly by the gamma rays at the doses studied. Moreover, those clostridia that survived the radiation treatments were found to remain at safe, low levels during the various periods in refrigerated storage employed for these products, a very encouraging result from the public health, as well as commercial, standpoint. PMID:13933508

Geopolymer encapsulation of a chloride salt phase change material for high temperature thermal energy storage

NASA Astrophysics Data System (ADS)

Jacob, Rhys; Trout, Neil; Raud, Ralf; Clarke, Stephen; Steinberg, Theodore A.; Saman, Wasim; Bruno, Frank

2016-05-01

In an effort to reduce the cost and increase the material compatibility of encapsulated phase change materials (EPCMs) a new encapsulated system has been proposed. In the current study a molten salt eutectic of barium chloride (53% wt.), potassium chloride (28% wt.) and sodium chloride (19% wt.) has been identified as a promising candidate for low cost EPCM storage systems. The latent heat, melting point and thermal stability of the phase change material (PCM) was determined by DSC and was found to be in good agreement with results published in the literature. To cope with the corrosive nature of the PCM, it was decided that a fly-ash based geopolymer met the thermal and economic constraints for encapsulation. The thermal stability of the geopolymer shell was also tested with several formulations proving to form a stable shell for the chosen PCM at 200°C and/or 600°C. Lastly several capsules of the geopolymer shell with a chloride PCM were fabricated using a variety of methods with several samples remaining stable after exposure to 600°C testing.

In-Flight Aeroelastic Stability of the Thermal Protection System on the NASA HIAD, Part I: Linear Theory

NASA Technical Reports Server (NTRS)

Goldman, Benjamin D.; Dowell, Earl H.; Scott, Robert C.

2014-01-01

Conical shell theory and piston theory aerodynamics are used to study the aeroelastic stability of the thermal protection system (TPS) on the NASA Hypersonic Inflatable Aerodynamic Decelerator (HIAD). Structural models of the TPS consist of single or multiple orthotropic conical shell systems resting on several circumferential linear elastic supports. The shells in each model may have pinned (simply-supported) or elastically-supported edges. The Lagrangian is formulated in terms of the generalized coordinates for all displacements and the Rayleigh-Ritz method is used to derive the equations of motion. The natural modes of vibration and aeroelastic stability boundaries are found by calculating the eigenvalues and eigenvectors of a large coefficient matrix. When the in-flight configuration of the TPS is approximated as a single shell without elastic supports, asymmetric flutter in many circumferential waves is observed. When the elastic supports are included, the shell flutters symmetrically in zero circumferential waves. Structural damping is found to be important in this case. Aeroelastic models that consider the individual TPS layers as separate shells tend to flutter asymmetrically at high dynamic pressures relative to the single shell models. Several parameter studies also examine the effects of tension, orthotropicity, and elastic support stiffness.

Factorization in large-scale many-body calculations

DOE PAGES

Johnson, Calvin W.; Ormand, W. Erich; Krastev, Plamen G.

2013-08-07

One approach for solving interacting many-fermion systems is the configuration-interaction method, also sometimes called the interacting shell model, where one finds eigenvalues of the Hamiltonian in a many-body basis of Slater determinants (antisymmetrized products of single-particle wavefunctions). The resulting Hamiltonian matrix is typically very sparse, but for large systems the nonzero matrix elements can nonetheless require terabytes or more of storage. An alternate algorithm, applicable to a broad class of systems with symmetry, in our case rotational invariance, is to exactly factorize both the basis and the interaction using additive/multiplicative quantum numbers; such an algorithm recreates the many-body matrix elementsmore » on the fly and can reduce the storage requirements by an order of magnitude or more. Here, we discuss factorization in general and introduce a novel, generalized factorization method, essentially a ‘double-factorization’ which speeds up basis generation and set-up of required arrays. Although we emphasize techniques, we also place factorization in the context of a specific (unpublished) configuration-interaction code, BIGSTICK, which runs both on serial and parallel machines, and discuss the savings in memory due to factorization.« less

Electron molecular ion recombination: product excitation and fragmentation.

PubMed

Adams, Nigel G; Poterya, Viktoriya; Babcock, Lucia M

2006-01-01

Electron-ion dissociative recombination is an important ionization loss process in any ionized gas containing molecular ions. This includes the interstellar medium, circumstellar shells, cometary comae, planetary ionospheres, fusion plasma boundaries, combustion flames, laser plasmas and chemical deposition and etching plasmas. In addition to controlling the ionization density, the process generates many radical species, which can contribute to a parallel neutral chemistry. Techniques used to obtain rate data and product information (flowing afterglows and storage rings) are discussed and recent data are reviewed including diatomic to polyatomic ions and cluster ions. The data are divided into rate coefficients and cross sections, including their temperature/energy dependencies, and quantitative identification of neutral reaction products. The latter involve both ground and electronically excited states and including vibrational excitation. The data from the different techniques are compared and trends in the data are examined. The reactions are considered in terms of the basic mechanisms (direct and indirect processes including tunneling) and recent theoretical developments are discussed. Finally, new techniques are mentioned (for product identification; electrostatic storage rings, including single and double rings; Coulomb explosion) and new ways forward are suggested.

Chemical insights into the roles of nanowire cores on the growth and supercapacitor performances of Ni-Co-O/Ni(OH)2 core/shell electrodes

PubMed Central

Yin, Xuesong; Tang, Chunhua; Zhang, Liuyang; Yu, Zhi Gen; Gong, Hao

2016-01-01

Nanostructured core/shell electrodes have been experimentally demonstrated promising for high-performance electrochemical energy storage devices. However, chemical insights into the significant roles of nanowire cores on the growth of shells and their supercapacitor behaviors still remain as a research shortfall. In this work, by substituting 1/3 cobalt in the Co3O4 nanowire core with nickel, a 61% enhancement of the specific mass-loading of the Ni(OH)2 shell, a tremendous 93% increase of the volumetric capacitance and a superior cyclability were achieved in a novel NiCo2O4/Ni(OH)2 core/shell electrode in contrast to a Co3O4/Ni(OH)2 one. A comparative study suggested that not only the growth of Ni(OH)2 shells but also the contribution of cores were attributed to the overall performances. Importantly, their chemical origins were revealed through a theoretical simulation of the core/shell interfacial energy changes. Besides, asymmetric supercapacitor devices and applications were also explored. The scientific clues and practical potentials obtained in this work are helpful for the design and analysis of alternative core/shell electrode materials. PMID:26857606

Chemical insights into the roles of nanowire cores on the growth and supercapacitor performances of Ni-Co-O/Ni(OH)₂ core/shell electrodes.

PubMed

Yin, Xuesong; Tang, Chunhua; Zhang, Liuyang; Yu, Zhi Gen; Gong, Hao

2016-02-09

Nanostructured core/shell electrodes have been experimentally demonstrated promising for high-performance electrochemical energy storage devices. However, chemical insights into the significant roles of nanowire cores on the growth of shells and their supercapacitor behaviors still remain as a research shortfall. In this work, by substituting 1/3 cobalt in the Co3O4 nanowire core with nickel, a 61% enhancement of the specific mass-loading of the Ni(OH)2 shell, a tremendous 93% increase of the volumetric capacitance and a superior cyclability were achieved in a novel NiCo2O4/Ni(OH)2 core/shell electrode in contrast to a Co3O4/Ni(OH)2 one. A comparative study suggested that not only the growth of Ni(OH)2 shells but also the contribution of cores were attributed to the overall performances. Importantly, their chemical origins were revealed through a theoretical simulation of the core/shell interfacial energy changes. Besides, asymmetric supercapacitor devices and applications were also explored. The scientific clues and practical potentials obtained in this work are helpful for the design and analysis of alternative core/shell electrode materials.

Mechanical ball-milling preparation of fullerene/cobalt core/shell nanocomposites with high electrochemical hydrogen storage ability.

PubMed

Bao, Di; Gao, Peng; Shen, Xiande; Chang, Cheng; Wang, Longqiang; Wang, Ying; Chen, Yujin; Zhou, Xiaoming; Sun, Shuchao; Li, Guobao; Yang, Piaoping

2014-02-26

The design and synthesis of new hydrogen storage nanomaterials with high capacity at low cost is extremely desirable but remains challenging for today's development of hydrogen economy. Because of the special honeycomb structures and excellent physical and chemical characters, fullerenes have been extensively considered as ideal materials for hydrogen storage materials. To take the most advantage of its distinctive symmetrical carbon cage structure, we have uniformly coated C60's surface with metal cobalt in nanoscale to form a core/shell structure through a simple ball-milling process in this work. The X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectra, high-solution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectrometry (EDX) elemental mappings, and X-ray photoelectron spectroscopy (XPS) measurements have been conducted to evaluate the size and the composition of the composites. In addition, the blue shift of C60 pentagonal pinch mode demonstrates the formation of Co-C chemical bond, and which enhances the stability of the as-obtained nanocomposites. And their electrochemical experimental results demonstrate that the as-obtained C60/Co composites have excellent electrochemical hydrogen storage cycle reversibility and considerably high hydrogen storage capacities of 907 mAh/g (3.32 wt % hydrogen) under room temperature and ambient pressure, which is very close to the theoretical hydrogen storage capacities of individual metal Co (3.33 wt % hydrogen). Furthermore, their hydrogen storage processes and the mechanism have also been investigated, in which the quasi-reversible C60/Co↔C60/Co-Hx reaction is the dominant cycle process.

Diagenetic changes in Concholepas concholepas shells (Gastropoda, Muricidae) in the hyper-arid conditions of Northern Chile - implications for palaeoenvironmental reconstructions

NASA Astrophysics Data System (ADS)

Guzmán, N.; Dauphin, Y.; Cuif, J. P.; Denis, A.; Ortlieb, L.

2009-02-01

Variations in the chemical composition of fossil biogenic carbonates, and in particular of mollusc shells, have been used in a range of palaeoenvironmental reconstructions. It is of primary importance, therefore, to detect and understand the diagenetic processes that may modify the original chemical signature. This microstructural and biogeochemical study focuses on modern and fossil (Holocene and Pleistocene) shells of a littoral gastropod of Northern Chile, and on the characterization of mineral component transformations at the nanometric scale and concomitant intracrystalline organic compound modifications. The inner aragonite layer of the shell exhibits more complex deteriorations than the calcite layer. This preliminary study confirms that physical and chemical alterations of various components of mollusc shell biocrystals are complex and might manifest in different ways even within a single individual. The single criterion of determining the mineralogical composition to verify the conservation state of shell samples is insufficient.

Diagenetic changes in Concholepas concholepas shells (Gastropoda, Muricidae) in the hyper-arid conditions of Northern Chile - implications for palaeoenvironmental reconstructions

NASA Astrophysics Data System (ADS)

Guzman, N.; Dauphin, Y.; Cuif, J. P.; Denis, A.; Ortlieb, L.

2008-02-01

Variations on chemical composition in fossil biogenic carbonates, and in particular of mollusk shells, have been used in a range of palaeoenvironmental reconstructions. Therefore, it is of primary importance to detect and understand the diagenetic processes that may modify the original chemical signature. This microstructural and biogeochemical study focuses on modern and fossil (Pleistocene and Holocene) shells of a littoral gastropod of Northern Chile, and on the characterization of mineral component transformations at the nanometric scale and concomitant intracrystalline organic compound modifications. The inner aragonite layer of the shell exhibits more complex deteriorations than the calcite layer. This preliminary study confirms that physical and chemical alterations of various components of mollusk shell biocrystals are complex and might manifest in different ways even within a single individual. The single criterion of determining the mineralogical composition to attest shell sample conservation state should not be considered as sufficient.

Tunable Free-Standing Core-Shell CNT@MoSe2 Anode for Lithium Storage.

PubMed

Yousaf, Muhammad; Wang, Yunsong; Chen, Yijun; Wang, Zhipeng; Aftab, Waseem; Mahmood, Asif; Wang, Wei; Guo, Shaojun; Han, Ray P S

2018-05-02

Heterogeneous nanostructuring of MoSe 2 over a carbon nanotube (CNT) sponge as a free-standing electrode not only brings higher performance but also eliminates the need for dead elements such as a binder, conductive carbon, and supportive current collectors. Further, the porous CNT sponge can be easily compacted via an intense densification of the active material MoSe 2 to produce an electrode with a high mass loading for a significantly improved areal capacity. In this work, we present a tunable coating of MoSe 2 on a CNT sponge to fabricate a core-shell MoSe 2 @CNT anode. The three-dimensional nanotubular sponge is synthesized via a solvothermal process, followed by thermal annealing to improve crystallization. Structural and morphological studies revealed that MoSe 2 grew as a layered structure ( d = 0.66 nm), where numbers of layers can be controlled to yield optimized results for Li + storage. We showed that the 10-layer core-shell CNT@MoSe 2 hybrid sponge delivered a discharge capacity of 820.5 mAh g -1 after 100 cycles at 100 mA g -1 with a high cyclic stability and rate capability. Further, an ex situ structural and morphological analysis revealed that ionic storage causes a phase change in MoSe 2 from a crystalline to a partial amorphous state for a continuous increase in the capacity with extended cycling. We believe that the strategy developed here will assist users to tune the electrode materials for future energy-storage devices, especially how the materials are changing with the passage of time and their effects on the device performance.

Singlet-paired coupled cluster theory for open shells

NASA Astrophysics Data System (ADS)

Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

2016-06-01

Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior for strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.

Nonpolar InGaN/GaN Core-Shell Single Nanowire Lasers.

PubMed

Li, Changyi; Wright, Jeremy B; Liu, Sheng; Lu, Ping; Figiel, Jeffrey J; Leung, Benjamin; Chow, Weng W; Brener, Igal; Koleske, Daniel D; Luk, Ting-Shan; Feezell, Daniel F; Brueck, S R J; Wang, George T

2017-02-08

We report lasing from nonpolar p-i-n InGaN/GaN multi-quantum well core-shell single-nanowire lasers by optical pumping at room temperature. The nanowire lasers were fabricated using a hybrid approach consisting of a top-down two-step etch process followed by a bottom-up regrowth process, enabling precise geometrical control and high material gain and optical confinement. The modal gain spectra and the gain curves of the core-shell nanowire lasers were measured using micro-photoluminescence and analyzed using the Hakki-Paoli method. Significantly lower lasing thresholds due to high optical gain were measured compared to previously reported semipolar InGaN/GaN core-shell nanowires, despite significantly shorter cavity lengths and reduced active region volume. Mode simulations show that due to the core-shell architecture, annular-shaped modes have higher optical confinement than solid transverse modes. The results show the viability of this p-i-n nonpolar core-shell nanowire architecture, previously investigated for next-generation light-emitting diodes, as low-threshold, coherent UV-visible nanoscale light emitters, and open a route toward monolithic, integrable, electrically injected single-nanowire lasers operating at room temperature.

Nonpolar InGaN/GaN core–shell single nanowire lasers

DOE PAGES

Li, Changyi; Wright, Jeremy Benjamin; Liu, Sheng; ...

2017-01-24

We report lasing from nonpolar p-i-n InGaN/GaN multi-quantum well core–shell single-nanowire lasers by optical pumping at room temperature. The nanowire lasers were fabricated using a hybrid approach consisting of a top-down two-step etch process followed by a bottom-up regrowth process, enabling precise geometrical control and high material gain and optical confinement. The modal gain spectra and the gain curves of the core–shell nanowire lasers were measured using micro-photoluminescence and analyzed using the Hakki-Paoli method. Significantly lower lasing thresholds due to high optical gain were measured compared to previously reported semipolar InGaN/GaN core–shell nanowires, despite significantly shorter cavity lengths and reducedmore » active region volume. Mode simulations show that due to the core–shell architecture, annular-shaped modes have higher optical confinement than solid transverse modes. Furthermore, the results show the viability of this p-i-n nonpolar core–shell nanowire architecture, previously investigated for next-generation light-emitting diodes, as low-threshold, coherent UV–visible nanoscale light emitters, and open a route toward monolithic, integrable, electrically injected single-nanowire lasers operating at room temperature.« less

7 CFR 51.1412 - Well cured.

Code of Federal Regulations, 2010 CFR

2010-01-01

... kernel separates freely from the shell, breaks cleanly when bent, without splintering, shattering, or loosening the skin; and the kernel appears to be in good shipping or storage condition as to moisture...

Space environmental considerations for a long-term cryogenic storage vessel

NASA Technical Reports Server (NTRS)

Nakanishi, Shigeo

1987-01-01

Information is given on the kind of protection that is needed against impact and perforation of a long-term cryogenic storage vessel in space by meteoroids and space debris. The long-term effects of the space environment on thermal control surfaces and coatings, and the question of whether the insulation and thermal control surfaces should be encased in a vacuum jacket shell are discussed.

Geochemical Processes Data Package for the Vadose Zone in the Single-Shell Tank Waste Management Areas at the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantrell, Kirk J.; Zachara, John M.; Dresel, P. Evan

This data package discusses the geochemistry of vadose zone sediments beneath the single-shell tank farms at the U.S. Department of Energy’s (DOE’s) Hanford Site. The purpose of the report is to provide a review of the most recent and relevant geochemical process information available for the vadose zone beneath the single-shell tank farms and the Integrated Disposal Facility. Two companion reports to this one were recently published which discuss the geology of the farms (Reidel and Chamness 2007) and groundwater flow and contamination beneath the farms (Horton 2007).

Synthesis and Characterization of Microencapsulated Phase Change Materials with Poly(urea-urethane) Shells Containing Cellulose Nanocrystals.

PubMed

Yoo, Youngman; Martinez, Carlos; Youngblood, Jeffrey P

2017-09-20

The main objective of this study is to develop microencapsulation technology for thermal energy storage incorporating a phase change material (PCM) in a composite wall shell, which can be used to create a stable environment and allow the PCM to undergo phase change without any outside influence. Surface modification of cellulose nanocrystals (CNCs) was conducted by grafting poly(lactic acid) oligomers and oleic acid to improve the dispersion of nanoparticles in a polymeric shell. A microencapsulated phase change material (methyl laurate) with poly(urea-urethane) (PU) composite shells containing the hydrophobized cellulose nanocrystals (hCNCs) was fabricated using an in situ emulsion interfacial polymerization process. The encapsulation process of the PCMs with subsequent interfacial hCNC-PU to form composite microcapsules as well as their morphology, composition, thermal properties, and release rates was examined in this study. Oil soluble Sudan II dye solution in methyl laurate was used as a model hydrophobic fill, representing other latent fills with low partition coefficients, and their encapsulation efficiency as well as dye release rates were measured spectroscopically in a water medium. The influence of polyol content in the PU polymer matrix of microcapsules was investigated. An increase in polyol contents leads to an increase in the mean size of microcapsules but a decrease in the gel content (degree of cross-linking density) and permeability of their shell structure. The encapsulated PCMs for thermal energy storage demonstrated here exhibited promising performance for possible use in building or paving materials in terms of released heat, desired phase transformation temperature, chemical and physical stability, and concrete durability during placement.

Alternative reproductive tactics in snail shell-brooding cichlids diverge in energy reserve allocation.

PubMed

von Kuerthy, Corinna; Tschirren, Linda; Taborsky, Michael

2015-05-01

Life history theory predicts that the amount of resources allocated to reproduction should maximize an individual's lifetime reproductive success. So far, resource allocation in reproduction has been studied mainly in females. Intraspecific variation of endogenous energy storage and utilization patterns of males has received little attention, although these patterns may vary greatly between individuals pursuing alternative reproductive tactics (ARTs). ARTs are characterized by systematic variation of behavioral, physiological, and often morphological traits among same-sex conspecifics. Some individuals may rely on previously accumulated reserves, because of limited foraging opportunities during reproduction. Others may be able to continue foraging during reproduction, thus relying on reserves to a lesser extent. We therefore predicted that, if male tactics involve such divergent limitations and trade-offs within a species, ARTs should correspondingly differ in energy reserve allocation and utilization. To test this prediction, we studied short-term and long-term reserve storage patterns of males in the shell-brooding cichlid Lamprologus callipterus. In this species, bourgeois males investing in territory defense, courtship, and guarding of broods coexist with two distinct parasitic male tactics: (1) opportunistic sneaker males attempting to fertilize eggs by releasing sperm into the shell opening when a female is spawning; and (2) specialized dwarf males attempting to enter the shell past the spawning female to fertilize eggs from inside the shell. Sneaker males differed from other male types by showing the highest amount of accumulated short-term and long-term fat stores, apparently anticipating their upcoming adoption of the nest male status. In contrast, nest males depleted previously accumulated energy reserves with increasing nest holding period, as they invest heavily into costly reproductive behaviors while not taking up any food. This conforms to a capital breeder strategy. Dwarf males did not accumulate long-term fat stores at all, which they can afford due to their small behavioral effort during reproduction and their continued feeding activity, conforming to an income breeder strategy. Our data confirm that the resource storage patterns of males pursuing ARTs can diverge substantially, which adds to our understanding of the coexistence and maintenance of alternative reproductive patterns within species.

Alternative reproductive tactics in snail shell-brooding cichlids diverge in energy reserve allocation

PubMed Central

von Kuerthy, Corinna; Tschirren, Linda; Taborsky, Michael

2015-01-01

Life history theory predicts that the amount of resources allocated to reproduction should maximize an individual's lifetime reproductive success. So far, resource allocation in reproduction has been studied mainly in females. Intraspecific variation of endogenous energy storage and utilization patterns of males has received little attention, although these patterns may vary greatly between individuals pursuing alternative reproductive tactics (ARTs). ARTs are characterized by systematic variation of behavioral, physiological, and often morphological traits among same-sex conspecifics. Some individuals may rely on previously accumulated reserves, because of limited foraging opportunities during reproduction. Others may be able to continue foraging during reproduction, thus relying on reserves to a lesser extent. We therefore predicted that, if male tactics involve such divergent limitations and trade-offs within a species, ARTs should correspondingly differ in energy reserve allocation and utilization. To test this prediction, we studied short-term and long-term reserve storage patterns of males in the shell-brooding cichlid Lamprologus callipterus. In this species, bourgeois males investing in territory defense, courtship, and guarding of broods coexist with two distinct parasitic male tactics: (1) opportunistic sneaker males attempting to fertilize eggs by releasing sperm into the shell opening when a female is spawning; and (2) specialized dwarf males attempting to enter the shell past the spawning female to fertilize eggs from inside the shell. Sneaker males differed from other male types by showing the highest amount of accumulated short-term and long-term fat stores, apparently anticipating their upcoming adoption of the nest male status. In contrast, nest males depleted previously accumulated energy reserves with increasing nest holding period, as they invest heavily into costly reproductive behaviors while not taking up any food. This conforms to a capital breeder strategy. Dwarf males did not accumulate long-term fat stores at all, which they can afford due to their small behavioral effort during reproduction and their continued feeding activity, conforming to an income breeder strategy. Our data confirm that the resource storage patterns of males pursuing ARTs can diverge substantially, which adds to our understanding of the coexistence and maintenance of alternative reproductive patterns within species. PMID:26045956

Assessment of single-shell tank residual-liquid issues at Hanford Site, Washington

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murthy, K.S.; Stout, L.A.; Napier, B.A.

1983-06-01

This report provides an assessment of the overall effectiveness and implications of jet pumping the interstitial liquids (IL) from single-shell tanks at Hanford. The jet-pumping program, currently in progress at Hanford, involves the planned removal of IL contained in 89 of the 149 single-shell tanks and its transfer to double-shell tanks after volume reduction by evaporation. The purpose of this report is to estimate the public and worker doses associated with (1) terminating pumping immediately, (2) pumping to a 100,000-gal limit per tank, (3) pumping to a 50,000-gal limit per tank, and (4) pumping to the maximum practical liquid removalmore » level of 30,000 gal. Assessment of the cost-effectiveness of these various levels of pumping in minimizing any undue health and safety risks to the public or worker is also presented.« less

A Review: Enhanced Anodes of Li/Na-Ion Batteries Based on Yolk-Shell Structured Nanomaterials

NASA Astrophysics Data System (ADS)

Wu, Cuo; Tong, Xin; Ai, Yuanfei; Liu, De-Sheng; Yu, Peng; Wu, Jiang; Wang, Zhiming M.

2018-09-01

Lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) have received much attention in energy storage system. In particular, among the great efforts on enhancing the performance of LIBs and SIBs, yolk-shell (YS) structured materials have emerged as a promising strategy toward improving lithium and sodium storage. YS structures possess unique interior void space, large surface area and short diffusion distance, which can solve the problems of volume expansion and aggregation of anode materials, thus enhancing the performance of LIBs and SIBs. In this review, we present a brief overview of recent advances in the novel YS structures of spheres, polyhedrons and rods with controllable morphology and compositions. Enhanced electrochemical performance of LIBs and SIBs based on these novel YS structured anode materials was discussed in detail. [Figure not available: see fulltext.

3D nitrogen-doped graphene foam with encapsulated germanium/nitrogen-doped graphene yolk-shell nanoarchitecture for high-performance flexible Li-ion battery

PubMed Central

Mo, Runwei; Rooney, David; Sun, Kening; Yang, Hui Ying

2017-01-01

Flexible electrochemical energy storage devices have attracted extensive attention as promising power sources for the ever-growing field of flexible and wearable electronic products. However, the rational design of a novel electrode structure with a good flexibility, high capacity, fast charge–discharge rate and long cycling lifetimes remains a long-standing challenge for developing next-generation flexible energy-storage materials. Herein, we develop a facile and general approach to three-dimensional (3D) interconnected porous nitrogen-doped graphene foam with encapsulated Ge quantum dot/nitrogen-doped graphene yolk-shell nano architecture for high specific reversible capacity (1,220 mAh g−1), long cycling capability (over 96% reversible capacity retention from the second to 1,000 cycles) and ultra-high rate performance (over 800 mAh g−1 at 40 C). This work paves a way to develop the 3D interconnected graphene-based high-capacity electrode material systems, particularly those that suffer from huge volume expansion, for the future development of high-performance flexible energy storage systems. PMID:28051065

Chitosan-based nanocoatings for hypothermic storage of living cells.

PubMed

Bulwan, Maria; Antosiak-Iwańska, Magdalena; Godlewska, Ewa; Granicka, Ludomira; Zapotoczny, Szczepan; Nowakowska, Maria

2013-11-01

The formation of ultrathin chitosan-based nanocoating on HL-60 model cells and their protective function in hypothermic storage are presented. HL-60 cells are encapsulated in ultrathin shells by adsorbing cationic and anionic chitosan derivatives in a stepwise, layer-by-layer, procedure carried out in an aqueous medium under mild conditions. The chitosan-based films are also deposited on model lipid bilayer and the interactions are studied using ellipsometry and atomic force microscopy. The cells covered with the chitosan-based films and stored at 4 °C for 24 h express viability comparable to that of the control sample incubated at 37 °C, while the unprotected cells stored under the same conditions do not show viability. It is shown that the chitosan-based shell protects HL-60 cells against damaging effect of hypothermic storage. Such nanocoatings provide protection, mechanical stability, and support the cell membrane, while ensuring penetration of small molecules such as nutrients/gases what is essential for cell viability. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diffraction data of core-shell nanoparticles from an X-ray free electron laser

DOE PAGES

Li, Xuanxuan; Chiu, Chun -Ya; Wang, Hsiang -Ju; ...

2017-04-11

X-ray free-electron lasers provide novel opportunities to conduct single particle analysis on nanoscale particles. Coherent diffractive imaging experiments were performed at the Linac Coherent Light Source (LCLS), SLAC National Laboratory, exposing single inorganic core-shell nanoparticles to femtosecond hard-X-ray pulses. Each facetted nanoparticle consisted of a crystalline gold core and a differently shaped palladium shell. Scattered intensities were observed up to about 7 nm resolution. Analysis of the scattering patterns revealed the size distribution of the samples, which is consistent with that obtained from direct real-space imaging by electron microscopy. Furthermore, scattering patterns resulting from single particles were selected and compiledmore » into a dataset which can be valuable for algorithm developments in single particle scattering research.« less

Target electron ionization in Li2+-Li collisions: A multi-electron perspective

NASA Astrophysics Data System (ADS)

Śpiewanowski, M. D.; Gulyás, L.; Horbatsch, M.; Kirchner, T.

2015-05-01

The recent development of the magneto-optical trap reaction-microscope has opened a new chapter for detailed investigations of charged-particle collisions from alkali atoms. It was shown that energy-differential cross sections for ionization from the outer-shell in O8+-Li collisions at 1500 keV/amu can be readily explained with the single-active-electron approximation. Understanding of K-shell ionization, however, requires incorporating many-electron effects. An ionization-excitation process was found to play an important role. We present a theoretical study of target electron removal in Li2+-Li collisions at 2290 keV/amu. The results indicate that in outer-shell ionization a single-electron process plays the dominant part. However, the K-shell ionization results are more difficult to interpret. On one hand, we find only weak contributions from multi-electron processes. On the other hand, a large discrepancy between experimental and single-particle theoretical results indicate that multi-electron processes involving ionization from the outer shell may be important for a complete understanding of the process. Work supported by NSERC, Canada and the Hungarian Scientific Research Fund.

Perspectives on land snails - sampling strategies for isotopic analyses

NASA Astrophysics Data System (ADS)

Kwiecien, Ola; Kalinowski, Annika; Kamp, Jessica; Pellmann, Anna

2017-04-01

Since the seminal works of Goodfriend (1992), several substantial studies confirmed a relation between the isotopic composition of land snail shells (d18O, d13C) and environmental parameters like precipitation amount, moisture source, temperature and vegetation type. This relation, however, is not straightforward and site dependent. The choice of sampling strategy (discrete or bulk sampling) and cleaning procedure (several methods can be used, but comparison of their effects in an individual shell has yet not been achieved) further complicate the shell analysis. The advantage of using snail shells as environmental archive lies in the snails' limited mobility, and therefore an intrinsic aptitude of recording local and site-specific conditions. Also, snail shells are often found at dated archaeological sites. An obvious drawback is that shell assemblages rarely make up a continuous record, and a single shell is only a snapshot of the environmental setting at a given time. Shells from archaeological sites might represent a dietary component and cooking would presumably alter the isotopic signature of aragonite material. Consequently, a proper sampling strategy is of great importance and should be adjusted to the scientific question. Here, we compare and contrast different sampling approaches using modern shells collected in Morocco, Spain and Germany. The bulk shell approach (fine-ground material) yields information on mean environmental parameters within the life span of analyzed individuals. However, despite homogenization, replicate measurements of bulk shell material returned results with a variability greater than analytical precision (up to 2‰ for d18O, and up to 1‰ for d13C), calling for caution analyzing only single individuals. Horizontal high-resolution sampling (single drill holes along growth lines) provides insights into the amplitude of seasonal variability, while vertical high-resolution sampling (multiple drill holes along the same growth line) produces replicable results. This reproducibility enables not only sequential testing of isotopic changes in shells exposed to artificially elevated temperatures, but also systematic assessment of different cleaning methods. Goodfriend, 1992. The use of land snail shells in paleoenvironmental reconstruction, EPSL 11, 655-685

High temperature thermal energy storage, including a discussion of TES integrated into power plants

NASA Technical Reports Server (NTRS)

Turner, R. H.

1978-01-01

Storage temperatures of 260 C and above are considered. Basic considerations concerning energy thermal storage are discussed, taking into account general aspects of thermal energy storage, thermal energy storage integrated into power plants, thermal storage techniques and technical considerations, and economic considerations. A description of system concepts is provided, giving attention to a survey of proposed concepts, storage in unpressurized fluids, water storage in pressurized containers, the use of an underground lined cavern for water storage, a submerged thin insulated steel shell under the ocean containing pressurized water, gas passage through solid blocks, a rock bed with liquid heat transport fluid, hollow steel ingots, heat storage in concrete or sand, sand in a fluidized bed, sand poured over pipes, a thermal energy storage heat exchanger, pipes or spheres filled with phase change materials (PCM), macroencapsulated PCM with heat pipe concept for transport fluid, solid PCM removed from heat transfer pipes by moving scrapers, and the direct contact between PCM and transport fluid.

Iron Oxide Nanosheets and Pulse-Electrodeposited Ni-Co-S Nanoflake Arrays for High-Performance Charge Storage.

PubMed

Khani, Hadi; Wipf, David O

2017-03-01

Nanostructured nickel cobalt sulfide (Ni 4.5 Co 4.5 S 8 ) has been prepared through a single-step pulse-electrodeposition method. Iron oxide nanosheets at hollow graphite shells (Fe 3 O 4 @g-shells) were prepared from graphite-coated iron carbide/α-Fe (g-Fe 3 C/Fe) in a two-step annealing/electrochemical cycling process. Electrochemical characterization of the Ni 4.5 Co 4.5 S 8 and g-Fe 3 C/Fe materials showed that both have high specific capacities (206 mAh g -1 and 147 mAh g -1 at 1 A g -1 ) and excellent rate capabilities (∼95% and ∼83% retention at 20 A g -1 , respectively). To demonstrate the advantageous pairing of these high rate materials, a full-cell battery with supercapacitor-like power behavior was assembled with Ni 4.5 Co 4.5 S 8 and g-Fe 3 C/Fe as the positive and negative electrodes, respectively. The (Ni 4.5 Co 4.5 S 8 //g-Fe 3 C/Fe) device could be reversibly operated in a 0.0-1.6 V potential window, delivering an impressive specific energy of 89 Wh kg -1 at 1.1 kW kg -1 and a remarkable rate performance of 61 Wh kg -1 at a very high specific power of 38.5 kW kg -1 . Additionally, long-term cycling demonstrated that the asymmetric full cell assembly retained 91% of its initial specific capacity after 2500 cycles at 40 A g -1 . The performance features of this device are among the best for iron oxide/hydroxide and bimetallic sulfide based energy storage devices to date, thereby giving insight into design principles for the next generation high-energy-density devices.

Testing the assumption of annual shell ring deposition in freshwater mussels

Treesearch

Wendell R. Haag; Amy M. Commens-Carson

2008-01-01

We tested the assumption of annual shell ring deposition by freshwater mussels in three rivers using 17 species. In 2000, we notched shell margins, returned animals to the water, and retrieved them in 2001. In 2003, we measured shells, affixed numbered tags, returned animals, and retrieved them in 2004 and 2005. We validated deposition of a single internal annulus per...

The oil palm Shell gene controls oil yield and encodes a homologue of SEEDSTICK

PubMed Central

Singh, Rajinder; Leslie Low, Eng-Ti; Ooi, Leslie Cheng-Li; Ong-Abdullah, Meilina; Chin, Ting Ngoot; Nagappan, Jayanthi; Nookiah, Rajanaidu; Amiruddin, Mohd Din; Rosli, Rozana; Abdul Manaf, Mohamad Arif; Chan, Kuang-Lim; Halim, Mohd Amin; Azizi, Norazah; Lakey, Nathan; Smith, Steven W; Budiman, Muhammad A; Hogan, Michael; Bacher, Blaire; Van Brunt, Andrew; Wang, Chunyan; Ordway, Jared M; Sambanthamurthi, Ravigadevi; Martienssen, Robert A

2014-01-01

A key event in the domestication and breeding of the oil palm, Elaeis guineensis, was loss of the thick coconut-like shell surrounding the kernel. Modern E. guineensis has three fruit forms, dura (thick-shelled), pisifera (shell-less) and tenera (thin-shelled), a hybrid between dura and pisifera1–4. The pisifera palm is usually female-sterile but the tenera yields far more oil than dura, and is the basis for commercial palm oil production in all of Southeast Asia5. Here, we describe the mapping and identification of the Shell gene responsible for the different fruit forms. Using homozygosity mapping by sequencing we found two independent mutations in the DNA binding domain of a homologue of the MADS-box gene SEEDSTICK (STK) which controls ovule identity and seed development in Arabidopsis. The Shell gene is responsible for the tenera phenotype in both cultivated and wild palms from sub-Saharan Africa, and our findings provide a genetic explanation for the single gene heterosis attributed to Shell, via heterodimerization. This gene mutation explains the single most important economic trait in oil palm, and has implications for the competing interests of global edible oil production, biofuels and rainforest conservation6. PMID:23883930

Study of the effect of varying core diameter, shell thickness and strain velocity on the tensile properties of single crystals of Cu-Ag core-shell nanowire using molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Sarkar, Jit; Das, D. K.

2018-01-01

Core-shell type nanostructures show exceptional properties due to their unique structure having a central solid core of one type and an outer thin shell of another type which draw immense attention among researchers. In this study, molecular dynamics simulations are carried out on single crystals of copper-silver core-shell nanowires having wire diameter ranging from 9 to 30 nm with varying core diameter, shell thickness, and strain velocity. The tensile properties like yield strength, ultimate tensile strength, and Young's modulus are studied and correlated by varying one parameter at a time and keeping the other two parameters constant. The results obtained for a fixed wire size and different strain velocities were extrapolated to calculate the tensile properties like yield strength and Young's modulus at standard strain rate of 1 mm/min. The results show ultra-high tensile properties of copper-silver core-shell nanowires, several times than that of bulk copper and silver. These copper-silver core-shell nanowires can be used as a reinforcing agent in bulk metal matrix for developing ultra-high strength nanocomposites.

Toxic-Waste Disposal by Combustion in Containers

NASA Technical Reports Server (NTRS)

Houseman, J.; Stephens, J. B.; Moynihan, P. I.; Compton, L. E.; Kalvinskas, J. J.

1986-01-01

Chemical wastes burned with minimal handling in storage containers. Technique for disposing of chemical munitions by burning them inside shells applies to disposal of toxic materials stored in drums. Fast, economical procedure overcomes heat-transfer limitations of conventional furnace designs by providing direct contact of oxygenrich combustion gases with toxic agent. No need to handle waste material, and container also decontaminated in process. Oxygen-rich torch flame cuts burster well and causes vaporization and combustion of toxic agent contained in shell.

Microwave moisture meter for in-shell almonds.

USDA-ARS?s Scientific Manuscript database

Determining almond kernel moisture content while still in the shell is important for both almond growers and processors. A dielectric method was developed for almond kernel moisture determination from dielectric measurements on in-shell almonds at a single microwave frequency. A sample holder was fi...

Improvement of Progressive Damage Model to Predicting Crashworthy Composite Corrugated Plate

NASA Astrophysics Data System (ADS)

Ren, Yiru; Jiang, Hongyong; Ji, Wenyuan; Zhang, Hanyu; Xiang, Jinwu; Yuan, Fuh-Gwo

2018-02-01

To predict the crashworthy composite corrugated plate, different single and stacked shell models are evaluated and compared, and a stacked shell progressive damage model combined with continuum damage mechanics is proposed and investigated. To simulate and predict the failure behavior, both of the intra- and inter- laminar failure behavior are considered. The tiebreak contact method, 1D spot weld element and cohesive element are adopted in stacked shell model, and a surface-based cohesive behavior is used to capture delamination in the proposed model. The impact load and failure behavior of purposed and conventional progressive damage models are demonstrated. Results show that the single shell could simulate the impact load curve without the delamination simulation ability. The general stacked shell model could simulate the interlaminar failure behavior. The improved stacked shell model with continuum damage mechanics and cohesive element not only agree well with the impact load, but also capture the fiber, matrix debonding, and interlaminar failure of composite structure.

OVERVIEW OF ENHANCED HANFORD SINGLE-SHELL TANK (SST) INTEGRITY PROJECT - 12128

DOE Office of Scientific and Technical Information (OSTI.GOV)

VENETZ TJ; BOOMER KD; WASHENFELDER DJ

2012-01-25

To improve the understanding of the single-shell tanks integrity, Washington River Protection Solutions, LLC, the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank (SST) Integrity Project in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration, Seventeen of these recommendations were used to develop the basis for the M-45-10-1 Change Package for the Hanford Federalmore » Agreement and Compliance Order, which is also known as the Tri-Party Agreement. The change package identified two phases of work for SST integrity. The initial phase has been focused on efforts to envelope the integrity of the tanks. The initial phase was divided into two primary areas of investigation: structural integrity and leak integrity. If necessary based on the outcome from the initial work, a second phase would be focused on further definition of the integrity of the concrete and liners. Combined these two phases are designed to support the formal integrity assessment of the Hanford SSTs in 2018 by Independent Qualified Registered Engineer. The work to further define the DOE's understanding of the structural integrity SSTs involves preparing a modern Analysis of Record using a finite element analysis program. Structural analyses of the SSTs have been conducted since 1957, but these analyses used analog calculation, less rigorous models, or focused on individual structures. As such, an integrated understanding of all of the SSTs has not been developed to modern expectations. In support of this effort, other milestones will address the visual inspection of the tank concrete and the collection of concrete core samples from the tanks for analysis of current mechanics properties. The work on the liner leak integrity has examined the leaks from 23 tanks with liner failures. Individual leak assessments are being developed for each tank to identify the leak cause and location. Also a common cause study is being performed to take the data from individual tanks to look for trends in the failure. Supporting this work is an assessment of the leak rate from tanks at both Hanford and the Savannah River Site and a new method to locate leak sites in tank liner using ionic conductivity. A separate activity is being conducted to examine the propensity for corrosion in select single shell tanks with aggressive waste layers. The work for these two main efforts will provide the basis for the phase two planning. If the margins identified aren't sufficient to ensure the integrity through the life of the mission, phase two would focus on activities to further enhance the understanding of tank integrity. Also coincident with any phase-two work would be the integrity analysis for the tanks, which would be complete in 2018. With delays in the completion of waste treatment facilities at Hanford, greater reliance on safe, continued storage of waste in the single shell tanks is increased in importance. The goal of integrity assessment would provide basis to continue SST activities till the end of the treatment mission.« less

1999 Leak Detection and Monitoring and Mitigation Strategy Update

DOE Office of Scientific and Technical Information (OSTI.GOV)

OHL, P.C.

This document is a complete revision of WHC-SD-WM-ES-378, Rev 1. This update includes recent developments in Leak Detection, Leak Monitoring, and Leak Mitigation technologies, as well as, recent developments in single-shell tank retrieval technologies. In addition, a single-shell tank retrieval release protection strategy is presented.

Single and multi-layered core-shell structures based on ZnO nanorods obtained by aerosol assisted chemical vapor deposition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sáenz-Trevizo, A.; Amézaga-Madrid, P.; Pizá-Ruiz, P.

2015-07-15

Core–shell nanorod structures were prepared by a sequential synthesis using an aerosol assisted chemical vapor deposition technique. Several samples consisting of ZnO nanorods were initially grown over TiO{sub 2} film-coated borosilicate glass substrates, following the synthesis conditions reported elsewhere. Later on, a uniform layer consisting of individual Al, Ni, Ti or Fe oxides was grown onto ZnO nanorod samples forming the so-called single MO{sub x}/ZnO nanorod core–shell structures, where MO{sub x} was the metal oxide shell. Additionally, a three-layer core–shell sample was developed by growing Fe, Ti and Fe oxides alternately, onto the ZnO nanorods. The microstructure of the core–shellmore » materials was characterized by grazing incidence X-ray diffraction, scanning and transmission electron microscopy. Energy dispersive X-ray spectroscopy was employed to corroborate the formation of different metal oxides. X-ray diffraction outcomes for single core–shell structures showed solely the presence of ZnO as wurtzite and TiO{sub 2} as anatase. For the multi-layered shell sample, the existence of Fe{sub 2}O{sub 3} as hematite was also detected. Morphological observations suggested the existence of an outer material grown onto the nanorods and further microstructural analysis by HR-STEM confirmed the development of core–shell structures in all cases. These studies also showed that the individual Al, Fe, Ni and Ti oxide layers are amorphous; an observation that matched with X-ray diffraction analysis where no apparent extra oxides were detected. For the multi-layered sample, the development of a shell consisting of three different oxide layers onto the nanorods was found. Overall results showed that no alteration in the primary ZnO core was produced during the growth of the shells, indicating that the deposition technique used herein was and it is suitable for the synthesis of homogeneous and complex nanomaterials high in quality and purity. In addition, materials absorptance determined from the total transmittance and reflectance spectra revealed a broader absorption interval including visible light, indicating potential uses of these nanostructures on solar energy appliances. - Graphical abstract: Display Omitted - Highlights: • Uniform ZnO nanorods (core)–metal oxide (shell) were obtained sequentially by AACVD. • Shells were structured of homogeneous single or multi-layered non-mixed metal oxides. • ZnO nanorod core was preserved during the shell synthesis. • Optical absorptance revealed visible interval absorption for FeO{sub x} shell samples. • Materials can be suitable for photocatalytic or photovoltaic applications.« less

A core–shell electrode for dynamically and statically stable Li–S battery chemistry

DOE PAGES

Chung, Sheng-Heng; Chang, Chi-Hao; Manthiram, Arumugam

2016-08-17

Sulfur is an appealing cathode material for establishing advanced lithium batteries as it offers a high theoretical capacity of 1675 mA h g -1 at low material and operating costs. However, the lithium–sulfur (Li–S) electrochemical cells face several formidable challenges arising from both the materials chemistry (e.g., low electrochemical utilization of sulfur and severe polysulfide diffusion) and battery chemistry (e.g., dynamic and static instability and low sulfur loadings). Here in this study, we present the design of a core–shell cathode with a pure sulfur core shielded within a conductive shell-shaped electrode. The new electrode configuration allows Li–S cells to loadmore » with a high amount of sulfur (sulfur loadings of up to 30 mg cm -2 and sulfur content approaching 70 wt%). The core–shell cathodes demonstrate a superior dynamic and static electrochemical stability in Li–S cells. The high-loading cathodes exhibit (i) a high sulfur utilization of up to 97% at C/20–C/2 rates and (ii) a low self-discharge during long-term cell storage for a three-month rest period and at different cell-storage conditions. Finally, a polysulfide-trap cell configuration is designed to evidence the eliminations of polysulfide diffusion and to investigate the relationship between the electrode configuration and electrochemical characteristics. Finally, the comprehensive analytical results based on the high-loading cathodes suggest that (i) the core–shell cathode is a promising solution for designing highly reversible Li–S cells and (ii) the polysulfide-trap cell configuration is a viable approach to qualitatively evaluating the presence or absence of polysulfide diffusion.« less

Interfacial complexation in microfluidic droplets for single-step fabrication of microcapsule

NASA Astrophysics Data System (ADS)

Kaufman, Gilad; Nejati, Siamak; Sarfati, Raphael; Boltyanskiy, Rostislav; Williams, Danielle; Liu, Wei; Schloss, Ashley; Regan, Lynn; Yan, Elsa; Dufrense, Eric; Loewenberg, Michael; Osuji, Chinedum

We present microfluidic interfacial complexation in emulsion droplets as a simple single-step approach for fabricating a large variety of stable monodisperse microcapsules with tailored mechanical properties, protein binding and controlled release behavior. We rely on electrostatic interactions and hydrogen bonding to direct the assembly of complementary species at oil-water droplet interfaces to form microcapsules with polyelectrolyte shells, composite polyelectrolyte-nanoparticle shells, and copolymer-nanofiber shells. Additionally, we demonstrate the formation of microcapsules by adsorption of an amphiphilic bacterial hydrophobin, BslA, at oil-in-water and water-in-oil droplets, and protein capture on these capsules using engineered variants of the hydrophobin. We discuss the composition dependence of mechanical properties, shell thickness and release behavior, and regimes of stability for microcapsule fabrication. Nanoparticle based microcapsules display an intriguing plastic deformation response which enables the formation of large aspect ratio asperities by pipette aspiration of the shell.

Core excitations across the neutron shell gap in 207Tl

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, E.; Podolyák, Zs.; Grawe, H.

2015-05-05

The single closed-neutron-shell, one proton–hole nucleus 207Tl was populated in deep-inelastic collisions of a 208Pb beam with a 208Pb target. The yrast and near-yrast level scheme has been established up to high excitation energy, comprising an octupole phonon state and a large number of core excited states. Based on shell-model calculations, all observed single core excitations were established to arise from the breaking of the N=126 neutron core. While the shell-model calculations correctly predict the ordering of these states, their energies are compressed at high spins. It is concluded that this compression is an intrinsic feature of shell-model calculations usingmore » two-body matrix elements developed for the description of two-body states, and that multiple core excitations need to be considered in order to accurately calculate the energy spacings of the predominantly three-quasiparticle states.« less

Dynamic strength of cylindrical fiber-glass shells and basalt plastic shells under multiple explosive loading

NASA Astrophysics Data System (ADS)

Syrunin, M. A.; Fedorenko, A. G.

2006-08-01

We have shown experimentally that, for cylindrical shells made of oriented fiberglass platic and basalt plastic there exists a critical level of deformations, at which a structure sustains a given number of explosions from the inside. The magnitude of critical deformation for cylindrical fiberglass shells depends linearly on the logarithm of the number of loads that cause failure. For a given type of fiberglass, there is a limiting level of explosive action, at which the number of loads that do not lead to failure can be sufficiently large (more than ˜ 102). This level is attained under loads, which are an order of magnitude lower than the limiting loads under a single explosive action. Basalt plastic shells can be repeatedly used even at the loads, which cause deformation by ˜ 30-50% lower than the safe value ˜ 3.3.5% at single loading.

Case Study in Corporate Memory Recovery: Hanford Tank Farms Miscellaneous Underground Waste Storage Tanks - 15344

DOE Office of Scientific and Technical Information (OSTI.GOV)

Washenfelder, D. J.; Johnson, J. M.; Turknett, J. C.

In addition to managing the 177 underground waste storage tanks containing 212,000 m3 (56 million gal) of radioactive waste at the U. S. Department of Energy’s Hanford Site 200 Area Tank Farms, Washington River Protection Solutions LLC is responsible for managing numerous small catch tanks and special surveillance facilities. These are collectively known as “MUSTs” - Miscellaneous Underground Storage Tanks. The MUSTs typically collected drainage and flushes during waste transfer system piping changes; special surveillance facilities supported Tank Farm processes including post-World War II uranium recovery and later fission product recovery from tank wastes. Most were removed from service followingmore » deactivation of the single-shell tank system in 1980 and stabilized by pumping the remaining liquids from them. The MUSTs were isolated by blanking connecting transfer lines and adding weatherproofing to prevent rainwater entry. Over the next 30 years MUST operating records were dispersed into large electronic databases or transferred to the National Archives Regional Center in Seattle, Washington. During 2014 an effort to reacquire the historical bases for the MUSTs’ published waste volumes was undertaken. Corporate Memory Recovery from a variety of record sources allowed waste volumes to be initially determined for 21 MUSTs, and waste volumes to be adjusted for 37 others. Precursors and symptoms of Corporate Memory Loss were identified in the context of MUST records recovery.« less

Outlook and Challenges for Hydrogen Storage in Nanoporous Materials

DOE PAGES

Broom, D. P.; Webb, C. J.; Hurst, Katherine E.; ...

2016-02-16

Considerable progress has been made recently in the use of nanoporous materials for hydrogen storage. In our article, the current status of the field and future challenges are discussed, ranging from important open fundamental questions, such as the density and volume of the adsorbed phase and its relationship to overall storage capacity, to the development of new functional materials and complete storage system design. With regard to fundamentals, the use of neutron scattering to study adsorbed H 2, suitable adsorption isotherm equations, and the accurate computational modelling and simulation of H 2 adsorption are discussed. We cover new materials andmore » they include flexible metal–organic frameworks, core–shell materials, and porous organic cage compounds. The article concludes with a discussion of the experimental investigation of real adsorptive hydrogen storage tanks, the improvement in the thermal conductivity of storage beds, and new storage system concepts and designs.« less

Program Analysis and Design Requirements for tne National Science Center

DTIC Science & Technology

1991-02-01

shell of an old exposition building with secondhand furniture to display exhibit items, to the Ontario Science Center, which is a more modem building...Storage Area Pigeonhole storage cabinets for children’s school books , coats, and boots are provided at the Indianapolis Center. The Ontario center...used shopping carts for school groups to store their coats and books . They do not work well according to center staff and are cumbersome and unsightly

Properties and potential environmental applications of carbon adsorbents from waste tire rubber

USGS Publications Warehouse

Lehmann, C.M.B.; Rameriz, D.; Rood, M.J.; Rostam-Abadi, M.

2000-01-01

The properties of tire-derived carbon adsorbents (TDCA) produced from select tire chars were compared with those derived from an Illinois coal and pistachio nut shells. Chemical analyses of the TDCA indicated that these materials contain metallic elements not present in coal-and nut shell-derived carbons. These metals, introduced during the production of tire rubber, potentially catalyze steam gasification reactions of tire char. TDCA carbons contained larger meso-and macopore volumes than their counterparts derived from coal and nut shell (on the moisture-and ash-free-basis). Adsorptive properties of the tire-derived adsorbent carbons for air separation, gas storage, and gas clean up were also evaluated and compared with those of the coal-and nut shell derived carbons as well as a commercial activated carbon. The results revealed that TDCA carbons are suitable adsorbents for removing vapor-phase mercury from combustion flue gases and hazardous organic compounds from industrial gas streams.

Core-shell structured polystyrene/BaTiO3 hybrid nanodielectrics prepared by in situ RAFT polymerization: a route to high dielectric constant and low loss materials with weak frequency dependence.

PubMed

Yang, Ke; Huang, Xingyi; Xie, Liyuan; Wu, Chao; Jiang, Pingkai; Tanaka, Toshikatsu

2012-11-23

A novel route to prepare core-shell structured nanocomposites with excellent dielectric performance is reported. This approach involves the grafting of polystyrene (PS) from the surface of BaTiO(3) by an in situ RAFT polymerization. The core-shell structured PS/BaTiO(3) nanocomposites not only show significantly increased dielectric constant and very low dielectric loss, but also have a weak frequency dependence of dielectric properties over a wide range of frequencies. In addition, the dielectric constant of the nanocomposites can also be easily tuned by varying the thickness of the PS shell. Our method is very promising for preparing high-performance nanocomposites used in energy-storage devices. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Co@Pd core-shell nanoparticles embedded in nitrogen-doped porous carbon as dual functional electrocatalysts for both oxygen reduction and hydrogen evolution reactions.

PubMed

Yang, Hongyu; Tang, Zhenghua; Wang, Kai; Wu, Wen; Chen, Yinghuan; Ding, Zhaoqing; Liu, Zhen; Chen, Shaowei

2018-05-21

Developing efficient bi-functional electrocatalysts for both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) is crucial for producing hydrogen and utilizing hydrogen effectively to promote electrochemical energy storage in proton membrane exchange fuel cells (PEMFCs). Herein, we report Co@Pd core-shell nanoparticles encapsulated in porous carbon derived from zeolitic imidazolate framework 67 (ZIF-67) for both ORR and HER. The controlled pyrolysis of ZIF-67 can lead to the formation of Co nanoparticles encapsulated in nitrogen-doped porous carbon (Co NC), which subsequently underwent galvanic replacement with Na 2 PdCl 4 to form Co@Pd core-shell nanoparticles embedded in nitrogen-doped porous carbon (Co@Pd NC). The Co@Pd NC exhibited outperformance in ORR and HER than commercial Pd/C, as manifested by more positive onset potential and larger diffusion-limited current density in ORR tests, as well as a small overpotential to drive a current density of 10 mA cm -2 , and much lower Tafel slope in HER tests. It also demonstrated more robust long-term stability than commercial Pd/C for both ORR and HER. Multiple techniques inter-confirmed that the Pd loading in the sample was very low. The findings can pave a path for fabricating a core-shell structured nanocomposite with ultralow noble metal usage as a bifunctional catalyst for electrochemical energy storage and conversion with high-efficiency and remarkable longevity. Copyright © 2018 Elsevier Inc. All rights reserved.

Thermal effectiveness of multiple shell and tube pass TEMA E heat exchangers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pignotti, A.; Tamborenea, P.I.

1988-02-01

The thermal effectiveness of a TEMAE shell-and-tube heat exchanger, with one shell pass and an arbitrary number of tube passes, is determined under the usual simplifying assumptions of perfect transverse mixing of the shell fluid, no phase change, and temperature independence of the heat capacity rates and the heat transfer coefficient. A purely algebraic solution is obtained for the effectiveness as a functions of the heat capacity rate ratio and the number of heat transfer units. The case with M shell passes and N tube passes is easily expressed in terms of the single-shell-pass case.

Hollow Polycaprolactone Microspheres with/without a Single Surface Hole by Co-Electrospraying

PubMed Central

2017-01-01

We describe the co-electrospraying of hollow microspheres from a polycaprolactone (PCL) shell solution and various core solutions including water, cyclohexane, poly(ethylene oxide) (PEO), and polyethylene glycol (PEG), using different collectors. The morphologies of the resultant microspheres were characterized by scanning electron microscopy (SEM), confocal microscopy, and nano-X-ray computed tomography (nano-XCT). The core/shell solution miscibility played an important role in the co-electrospraying process and the formation of microsphere structures. Spherical particles were more likely to be produced from miscible combinations of core/shell solutions than from immiscible ones. Hollow PCL microspheres with a single hole in their surfaces were produced when an ethanol bath was used as the collector. The mechanism by which the core/shell structure is transformed into single-hole hollow microspheres is proposed to be primarily based on the evaporation through the shell and extraction by ethanol of the core solution and is described in detail. Additionally, we present a 3D macroscopic tubular structure composed of hollow PCL microspheres, directly assembled on a copper wire collector during co-electrospraying. SEM and nano-XCT confirm that microspheres in the 3D bulk structure remain hollow. PMID:28901145

Converting Multi-Shell and Diffusion Spectrum Imaging to High Angular Resolution Diffusion Imaging

PubMed Central

Yeh, Fang-Cheng; Verstynen, Timothy D.

2016-01-01

Multi-shell and diffusion spectrum imaging (DSI) are becoming increasingly popular methods of acquiring diffusion MRI data in a research context. However, single-shell acquisitions, such as diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), still remain the most common acquisition schemes in practice. Here we tested whether multi-shell and DSI data have conversion flexibility to be interpolated into corresponding HARDI data. We acquired multi-shell and DSI data on both a phantom and in vivo human tissue and converted them to HARDI. The correlation and difference between their diffusion signals, anisotropy values, diffusivity measurements, fiber orientations, connectivity matrices, and network measures were examined. Our analysis result showed that the diffusion signals, anisotropy, diffusivity, and connectivity matrix of the HARDI converted from multi-shell and DSI were highly correlated with those of the HARDI acquired on the MR scanner, with correlation coefficients around 0.8~0.9. The average angular error between converted and original HARDI was 20.7° at voxels with signal-to-noise ratios greater than 5. The network topology measures had less than 2% difference, whereas the average nodal measures had a percentage difference around 4~7%. In general, multi-shell and DSI acquisitions can be converted to their corresponding single-shell HARDI with high fidelity. This supports multi-shell and DSI acquisitions over HARDI acquisition as the scheme of choice for diffusion acquisitions. PMID:27683539

Self-monitored photothermal nanoparticles based on core-shell engineering

NASA Astrophysics Data System (ADS)

Ximendes, Erving C.; Rocha, Uéslen; Jacinto, Carlos; Kumar, Kagola Upendra; Bravo, David; López, Fernando J.; Rodríguez, Emma Martín; García-Solé, José; Jaque, Daniel

2016-01-01

The continuous development of nanotechnology has resulted in the actual possibility of the design and synthesis of nanostructured materials with pre-tailored functionabilities. Nanostructures capable of simultaneous heating and local thermal sensing are in strong demand as they would constitute a revolutionary solution to several challenging problems in bio-medicine, including the achievement of real time control during photothermal therapies. Several approaches have been demonstrated to achieve simultaneous heating and thermal sensing at the nanoscale. Some of them lack of sufficient thermal sensitivity and others require complicated synthesis procedures for heterostructure fabrication. In this study, we demonstrate how single core/shell dielectric nanoparticles with a highly Nd3+ ion doped shell and an Yb3+,Er3+ codoped core are capable of simultaneous thermal sensing and heating under an 808 nm single beam excitation. The spatial separation between the heating shell and sensing core provides remarkable values of the heating efficiency and thermal sensitivity, enabling their application in single beam-controlled heating experiments in both aqueous and tissue environments.

Vibrations and structureborne noise in space station

NASA Technical Reports Server (NTRS)

Vaicaitis, R.; Lyrintzis, C. S.; Bofilios, D. A.

1987-01-01

Analytical models were developed to predict vibrations and structureborne noise generation of cylindrical and rectangular acoustic enclosures. These models are then used to determine structural vibration levels and interior noise to random point input forces. The guidelines developed could provide preliminary information on acoustical and vibrational environments in space station habitability modules under orbital operations. The structural models include single wall monocoque shell, double wall shell, stiffened orthotropic shell, descretely stiffened flat panels, and a coupled system composed of a cantilever beam structure and a stiffened sidewall. Aluminum and fiber reinforced composite materials are considered for single and double wall shells. The end caps of the cylindrical enclosures are modeled either as single or double wall circular plates. Sound generation in the interior space is calculated by coupling the structural vibrations to the acoustic field in the enclosure. Modal methods and transfer matrix techniques are used to obtain structural vibrations. Parametric studies are performed to determine the sensitivity of interior noise environment to changes in input, geometric and structural conditions.

Ferrocyanide Safety Program. Quarterly report for the period ending March 31, 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meacham, J.E.; Cash, R.J.; Dukelow, G.T.

1994-04-01

Various high-level radioactive waste from defense operations has accumulated at the Hanford Site in underground storage tanks since the mid-1940s. During the 1950s, additional tank storage space was required to support the defense mission. To obtain this additional storage volume within a short time period, and to minimize the need for constructing additional storage tanks, Hanford Site scientists developed a process to scavenge {sup 137}Cs from tank waste liquids. In implementing this process, approximately 140 metric tons of ferrocyanide were added to waste that was later routed to some Hanford Site single-shell tanks. The reactive nature of ferrocyanide in themore » presence of an oxidizer has been known for decades, but the conditions under which the compound can undergo endothermic and exothermic reactions have not been thoroughly studied. Because the scavenging process precipitated ferrocyanide from solutions containing nitrate and nitrite, an intimate mixture of ferrocyanides and nitrates and/or nitrites is likely to exist in some regions of the ferrocyanide tanks. This quarterly report provides a status of the activities underway at the Hanford Site on the Ferrocyanide Safety Issue, as requested by the Defense Nuclear Facilities Safety Board (DNFSB) in their Recommendation 90-7. A revised Ferrocyanide Safety Program Plan addressing the total Ferrocyanide Safety Program, including the six parts of DNFSB Recommendation 90-7, was recently prepared and released in March 1994. Activities in the revised program plan are underway or have been completed, and the status of each is described in Section 4.0 of this report.« less

Influence of a finite number of baffles on shell-and-tube heat exchanger performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shah, R.K.; Pignotti, A.

1997-01-01

In single-phase shell-and-tube heat exchangers, thermal performance prediction is customarily accomplished with an idealization that the number of baffles used is very large and can be assumed to approach infinity. Under this idealization, the temperature change within each baffle compartment is very small in comparison with the total temperature change of the shell fluid through the heat exchanger. Thus the shell fluid can be considered as uniform (perfectly mixed) at every cross section (in a direction normal to the shell axis). It is with this model that the mean temperature difference correction factor is normally derived for single-phase exchangers. Inmore » reality, a finite number of baffles are used, and the condition stated above can be achieved only partially. In this article, a comprehensive review is made and new results are derived where needed to assess the influence of a finite number of baffles on heat transfer performance for 1-1, 1-2, and 1-N TEMA E, 1-2 TEMA J, and 1-2 TEMA G and H single-phase shell-and-tube exchangers. It is shown that the number of baffles required to achieve the performance within about 2% of an exchanger with an infinite number of baffles varies with the type of exchanger and the performance parameters. The new results are presented in tabular form.« less

Collapse dynamics of ultrasound contrast agent microbubbles

NASA Astrophysics Data System (ADS)

King, Daniel Alan

Ultrasound contrast agents (UCAs) are micron-sized gas bubbles encapsulated with thin shells on the order of nanometers thick. The damping effects of these viscoelastic coatings are widely known to significantly alter the bubble dynamics for linear and low-amplitude behavior; however, their effects on strongly nonlinear and destruction responses are much less studied. This dissertation examines the behaviors of single collapsing shelled microbubbles using experimental and theoretical methods. The study of their dynamics is particularly relevant for emerging experimental uses of UCAs which seek to leverage localized mechanical forces to create or avoid specialized biomedical effects. The central component in this work is the study of postexcitation rebound and collapse, observed acoustically to identify shell rupture and transient inertial cavitation of single UCA microbubbles. This time-domain analysis of the acoustic response provides a unique method for characterization of UCA destruction dynamics. The research contains a systematic documentation of single bubble postexcitation collapse through experimental measurement with the double passive cavitation detection (PCD) system at frequencies ranging from 0.9 to 7.1 MHz and peak rarefactional pressure amplitudes (PRPA) ranging from 230 kPa to 6.37 MPa. The double PCD setup is shown to improve the quality of collected data over previous setups by allowing symmetric responses from a localized confocal region to be identified. Postexcitation signal percentages are shown to generally follow trends consistent with other similar cavitation metrics such as inertial cavitation, with greater destruction observed at both increased PRPA and lower frequency over the tested ranges. Two different types of commercially available UCAs are characterized and found to have very different collapse thresholds; lipid-shelled Definity exhibits greater postexcitation at lower PRPAs than albumin-shelled Optison. Furthermore, by altering the size distributions of these UCAs, it is shown that the shell material has a large influence on the occurrence of postexcitation rebound at all tested frequencies while moderate alteration of the size distribution may only play a significant role within certain frequency ranges. Finally, the conditions which generate the experimental postexcitation signal are examined theoretically using several forms of single bubble models. Evidence is provided for the usefulness of modeling this large amplitude UCA behavior with a size-varying surface tension as described in the Marmottant model; better agreement for lipid-shelled Definity UCAs is obtained by considering the dynamic response with a rupturing shell rather than either a non-rupturing or nonexistent shell. Moreover, the modeling indicates that maximum radial expansion from the initial UCA size is a suitable metric to predict postexcitation collapse, and that both shell rupture and inertial cavitation are necessary conditions to generate this behavior. Postexcitation analysis is found to be a beneficial characterization metric for studying the destruction behaviors of single UCAs when measured with the double PCD setup. This work provides quantitative documentation of UCA collapse, exploration into UCA material properties which affect this collapse, and comparison of existing single bubble models with experimentally measured postexcitation signals.

Scallop-Inspired Shell Engineering of Microparticles for Stable and High Volumetric Capacity Battery Anodes.

PubMed

Zhang, Xinghao; Guo, Ruiying; Li, Xianglong; Zhi, Linjie

2018-06-01

Building stable and efficient electron and ion transport pathways are critically important for energy storage electrode materials and systems. Herein, a scallop-inspired shell engineering strategy is proposed and demonstrated to confine high volume change silicon microparticles toward the construction of stable and high volumetric capacity binder-free lithium battery anodes. As for each silicon microparticle, the methodology involves an inner sealed but adaptable overlapped graphene shell, and an outer open hollow shell consisting of interconnected reduced graphene oxide, mimicking the scallop structure. The inner closed shell enables simultaneous stabilization of the interfaces of silicon with both carbon and electrolyte, substantially facilitates efficient and rapid transport of both electrons and lithium ions from/to silicon, the outer open hollow shell creates stable and robust transport paths of both electrons and lithium ions throughout the electrode without any sophisticated additives. The resultant self-supported electrode has achieved stable cycling with rapidly increased coulombic efficiency in the early stage, superior rate capability, and remarkably high volumetric capacity upon a facile pressing process. The rational design and engineering of graphene shells of the silicon microparticles developed can provide guidance for the development of a wide range of other high capacity but large volume change electrochemically active materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrospun core-shell fibers for robust silicon nanoparticle-based lithium ion battery anodes.

PubMed

Hwang, Tae Hoon; Lee, Yong Min; Kong, Byung-Seon; Seo, Jin-Seok; Choi, Jang Wook

2012-02-08

Because of its unprecedented theoretical capacity near 4000 mAh/g, which is approximately 10-fold larger compared to those of the current commercial graphite anodes, silicon has been the most promising anode for lithium ion batteries, particularly targeting large-scale energy storage applications including electrical vehicles and utility grids. Nevertheless, Si suffers from its short cycle life as well as the limitation for scalable electrode fabrication. Herein, we develop an electrospinning process to produce core-shell fiber electrodes using a dual nozzle in a scalable manner. In the core-shell fibers, commercially available nanoparticles in the core are wrapped by the carbon shell. The unique core-shell structure resolves various issues of Si anode operations, such as pulverization, vulnerable contacts between Si and carbon conductors, and an unstable sold-electrolyte interphase, thereby exhibiting outstanding cell performance: a gravimetric capacity as high as 1384 mAh/g, a 5 min discharging rate capability while retaining 721 mAh/g, and cycle life of 300 cycles with almost no capacity loss. The electrospun core-shell one-dimensional fibers suggest a new design principle for robust and scalable lithium battery electrodes suffering from volume expansion. © 2011 American Chemical Society

Linear and nonlinear magneto-optical properties of an off-center single dopant in a spherical core/shell quantum dot

NASA Astrophysics Data System (ADS)

Feddi, E.; Talbi, A.; Mora-Ramos, M. E.; El Haouari, M.; Dujardin, F.; Duque, C. A.

2017-11-01

Using the effective mass approximation and a variational procedure, we have investigated the nonlinear optical absorption coefficient and the relative refractive index changes associated to a single dopant confined in core/shell quantum dots considering the influences of the core/shell dimensions, externally applied magnetic field, and dielectric mismatch. The results show that the optical absorption coefficient and the coefficients of relative refractive index change depend strongly on the core/shell sizes and they are blue shifted when the spatial confinement increases so this effect is magnified by higher structural dimensions. Additionally, it is obtained that both studied optical properties are sensitive to the dielectric environment in such a way that their amplitudes are very affected by the local field corrections.

High pressure treatment changes spoilage characteristics and shelf life of Pacific oysters ( Crassostrea gigas) during refrigerated storage

NASA Astrophysics Data System (ADS)

Cao, Rong; Zhao, Ling; Liu, Qi

2017-04-01

The effects of high pressure (HP) treatment on spoilage characteristic and shelf life extension of Pacific oysters ( Crassostrea gigas) during refrigerated storage were studied. Results showed that HP treatment of 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle, pressures higher than 350 MPa caused excessive release as the shells of oysters were broken, thus use of higher pressures should be cautious in oyster processing industry because of its adverse impact on the appearance of shells. HP treatment (300 MPa, 2 min) was proper for the shucking of Pacific oyster ( Crassostrea gigas) in China. This treatment caused no organoleptic disadvantage. Moreover, HP treatment resulted in obvious differences in biochemical spoilage indicators (pH, TVB-N and TBARS) changes and volatile compounds profile determined by electronic nose during storage. HP treatment (300 MPa, 2 min) also led to a reduction of aerobic bacterial count (APC) by 1.27 log cycles. Furthermore, the APC values of oysters treated by HP were always lower than those of the control samples during storage. Based on the organoleptic, biochemical and microbiological indicators, shelf life of 6-8 d for control and 12 d for HP-treated oysters could be expected. HP treatment showed great potential in oyster processing and preservation.

Maintaining functional properties of shell eggs by ultrasound treatment.

PubMed

Caner, Cengiz; Yuceer, Muhammed

2015-11-01

Ultrasonic treatment is an emerging technique that could be an alternative to existing thermal processing techniques in foods. Ultrasonic treatments may also be used to extend the shelf life of egg during storage period in ambient temperature. The effectiveness of ultrasound treatment with different power levels (200 W, 300 W, 450 W) and treatment times (2 min and 5 min) was evaluated for enhancing the functional properties of eggs during storage at 24 ° C for 6 weeks. Ultrasound treatment power and treatment time had significant effects on Haugh unit, yolk index, albumen pH, dry matter, relative whipping capacity, and albumen viscosity resulting in extended shelf life. Attributes such as yolk index, Haugh unit, pH, whipping capacity, dry matter for 300 W and 450 W treatments were better than control and 200 W treatments. Longer treatment time and power showed a significant influence on functional properties. Power levels of 300 W and 450 W of ultrasound treatments had improved internal quality of fresh eggs during storage, but negative effect on shell strength. The study showed that ultrasound treatment could be an alternative and effective technique for maintaining the internal qualities of fresh eggs during long-term storage while Fourier transform near infrared spectroscopy could be used as a new tool for the assessment of freshness. © 2014 Society of Chemical Industry.

LaF3 core/shell nanoparticles for subcutaneous heating and thermal sensing in the second biological-window

NASA Astrophysics Data System (ADS)

Ximendes, Erving Clayton; Rocha, Uéslen; Kumar, Kagola Upendra; Jacinto, Carlos; Jaque, Daniel

2016-06-01

We report on Ytterbium and Neodymium codoped LaF3 core/shell nanoparticles capable of simultaneous heating and thermal sensing under single beam infrared laser excitation. Efficient light-to-heat conversion is produced at the Neodymium highly doped shell due to non-radiative de-excitations. Thermal sensing is provided by the temperature dependent Nd3+ → Yb3+ energy transfer processes taking place at the core/shell interface. The potential application of these core/shell multifunctional nanoparticles for controlled photothermal subcutaneous treatments is also demonstrated.

CPA ups storage at Lavera site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Back, R.

Compagnie Parisienne des Asphaltes (CPA; Paris) and its subsidiary Pacsud -owned 65% by CPA and 35% by Shell Chimie (Paris) - have inaugurated their new chemicals storage site at Lavera, France, in the Europort South complex near Marseilles. The facilities, with 60,000-m.t./year capacity, also include a barreling plant that will have output of up to 250 bbl/hour when it comes onstream next spring. Total investment for these facilities amount to F122 million ($22.5 million), including F22 million for the barreling unit. CPA, France's number two storage specialist, after LB Chimie (Paris), is jointly owned by investment company Union Normandie (60%),more » Elf Aquitaine (Paris; 20%), and Total (Paris; 20%). Adding to its existing French storage sites at Dunkirk and Rouen, CPA says it decided to build on the Pacsud venture because it considered it attractive to invest in the petroleum and petrochemical complex of Fos-Berre-Lavera, particularly since the present trend in the oil and chemical industries is to subcontract all ancillary functions, especially logistics. CPA general manager Rafic Charles Rathle says that customer requirements and the role of the service provider are changing. With that in mid, CPA, in addition to providing storage terminals, converts its depots into distribution and packing centers. At Lavera the company has taken over storage, blending, and barreling operations for Pacsud and its direct customers. For example, Pacsud has a long-term contract with Shell Chimie for the latter's additive production at a 10,000-m.t./year rate. Another long-term contract is being negotiated, but the identity of the customer was not revealed.« less

Parametric design studies of toroidal magnetic energy storage units

NASA Astrophysics Data System (ADS)

Herring, J. Stephen

Superconducting magnetic energy storage (SMES) units have a number of advantages as storage devices. Electrical current is the input, output and stored medium, allowing for completely solid-state energy conversion. The magnets themselves have no moving parts. The round trip efficiency is higher than those for batteries, compressed air or pumped hydro. Output power can be very high, allowing complete discharge of the unit within a few seconds. Finally, the unit can be designed for a very large number of cycles, limited basically by fatigue in the structural components. A small systems code was written to produce and evaluate self-consistent designs for toroidal superconducting energy storage units. The units can use either low temperature or high temperature superconductors. The coils have D shape where the conductor and its stabilizer/structure is loaded only in tension and the centering forces are borne by a bucking cylinder. The coils are convectively cooled from a cryogenic reservoir in the bore of the coils. The coils are suspended in a cylindrical metal shell which protects the magnet during rail, automotive or shipboard use. It is important to note that the storage unit does not rely on its surroundings for structural support, other than normal gravity and inertial loads. Designs are presented for toroidal energy storage units produced by the systems code. A wide range of several parameters have been considered, resulting in units storing from 1 MJ to 72 GJ. Maximum fields range from 5 T to 20 T. The masses and volumes of the coils, bucking cylinder, coolant, insulation and outer shell are calculated. For unattended use, the allowable operating time using only the boiloff of the cryogenic fluid for refrigeration is calculated. For larger units, the coils were divided into modules suitable for normal truck or rail transport.

Shell Structure Water Cellar’s Rapid Construct Technology

NASA Astrophysics Data System (ADS)

Xian Zhuang, Wen; Qing Yin, De; Chen, Shu Fa

2018-05-01

Tradition concrete water cellar’s problems, such as high cost, long construction term, easy to crack, are pointed out. A new construct method, and it’s matching airbag mould, of constructing concrete shell structure water cellars, are introduced. Combine with full-scale verifying cellar’s construct test, full-load water storage test, analyzed the technology in terms of construction term, cost, crack resistance, air bag pressure etc. It is believed that this new technology can successfully solve the problems that tradition technology has, and it will have a good prospect in rainfall resources utilization.

Nanoencapsulation of phase change materials for advanced thermal energy storage systems

PubMed Central

Shchukina, E. M.; Graham, M.; Zheng, Z.

2018-01-01

Phase change materials (PCMs) allow the storage of large amounts of latent heat during phase transition. They have the potential to both increase the efficiency of renewable energies such as solar power through storage of excess energy, which can be used at times of peak demand; and to reduce overall energy demand through passive thermal regulation. 198.3 million tons of oil equivalent were used in the EU in 2013 for heating. However, bulk PCMs are not suitable for use without prior encapsulation. Encapsulation in a shell material provides benefits such as protection of the PCM from the external environment and increased specific surface area to improve heat transfer. This review highlights techniques for the encapsulation of both organic and inorganic PCMs, paying particular attention to nanoencapsulation (capsules with sizes <1 μm). We also provide insight on future research, which should focus on (i) the development of multifunctional shell materials to improve lifespan and thermal properties and (ii) advanced mass manufacturing techniques for the economically viable production of PCM capsules, making it possible to utilize waste heat in intelligent passive thermal regulation systems, employing controlled, “on demand” energy release/uptake. PMID:29658558

Nanoencapsulation of phase change materials for advanced thermal energy storage systems.

PubMed

Shchukina, E M; Graham, M; Zheng, Z; Shchukin, D G

2018-06-05

Phase change materials (PCMs) allow the storage of large amounts of latent heat during phase transition. They have the potential to both increase the efficiency of renewable energies such as solar power through storage of excess energy, which can be used at times of peak demand; and to reduce overall energy demand through passive thermal regulation. 198.3 million tons of oil equivalent were used in the EU in 2013 for heating. However, bulk PCMs are not suitable for use without prior encapsulation. Encapsulation in a shell material provides benefits such as protection of the PCM from the external environment and increased specific surface area to improve heat transfer. This review highlights techniques for the encapsulation of both organic and inorganic PCMs, paying particular attention to nanoencapsulation (capsules with sizes <1 μm). We also provide insight on future research, which should focus on (i) the development of multifunctional shell materials to improve lifespan and thermal properties and (ii) advanced mass manufacturing techniques for the economically viable production of PCM capsules, making it possible to utilize waste heat in intelligent passive thermal regulation systems, employing controlled, "on demand" energy release/uptake.

A coupled-cluster study of photodetachment cross sections of closed-shell anions

NASA Astrophysics Data System (ADS)

Cukras, Janusz; Decleva, Piero; Coriani, Sonia

2014-11-01

We investigate the performance of Stieltjes Imaging applied to Lanczos pseudo-spectra generated at the coupled cluster singles and doubles, coupled cluster singles and approximate iterative doubles and coupled cluster singles levels of theory in modeling the photodetachment cross sections of the closed shell anions H-, Li-, Na-, F-, Cl-, and OH-. The accurate description of double excitations is found to play a much more important role than in the case of photoionization of neutral species.

A coupled-cluster study of photodetachment cross sections of closed-shell anions.

PubMed

Cukras, Janusz; Decleva, Piero; Coriani, Sonia

2014-11-07

We investigate the performance of Stieltjes Imaging applied to Lanczos pseudo-spectra generated at the coupled cluster singles and doubles, coupled cluster singles and approximate iterative doubles and coupled cluster singles levels of theory in modeling the photodetachment cross sections of the closed shell anions H(-), Li(-), Na(-), F(-), Cl(-), and OH(-). The accurate description of double excitations is found to play a much more important role than in the case of photoionization of neutral species.

Progress of the Enhanced Hanford Single Shell Tank (SST) Integrity Project

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venetz, Theodore J.; Washenfelder, Dennis J.; Boomer, Kayle D.

2015-01-07

To improve the understanding of the single-shell tanks (SSTs) integrity, Washington River Protection Solutions, LLC (WRPS), the USDOE Hanford Site tank contractor, developed an enhanced Single-Shell Tank Integrity Project (SSTIP) in 2009. An expert panel on SST integrity, consisting of various subject matters experts in industry and academia, was created to provide recommendations supporting the development of the project. This panel developed 33 recommendations in four main areas of interest: structural integrity, liner degradation, leak integrity and prevention, and mitigation of contamination migration. In late 2010, seventeen of these recommendations were used to develop the basis for the M-45-10-1 Changemore » Package for the Hanford Federal Agreement and Compliance Order, which is also known as the Tri-Party Agreement.« less

Baseline Design Compliance Matrix for the Rotary Mode Core Sampling System

DOE Office of Scientific and Technical Information (OSTI.GOV)

LECHELT, J.A.

2000-10-17

The purpose of the design compliance matrix (DCM) is to provide a single-source document of all design requirements associated with the fifteen subsystems that make up the rotary mode core sampling (RMCS) system. It is intended to be the baseline requirement document for the RMCS system and to be used in governing all future design and design verification activities associated with it. This document is the DCM for the RMCS system used on Hanford single-shell radioactive waste storage tanks. This includes the Exhauster System, Rotary Mode Core Sample Trucks, Universal Sampling System, Diesel Generator System, Distribution Trailer, X-Ray Cart System,more » Breathing Air Compressor, Nitrogen Supply Trailer, Casks and Cask Truck, Service Trailer, Core Sampling Riser Equipment, Core Sampling Support Trucks, Foot Clamp, Ramps and Platforms and Purged Camera System. Excluded items are tools such as light plants and light stands. Other items such as the breather inlet filter are covered by a different design baseline. In this case, the inlet breather filter is covered by the Tank Farms Design Compliance Matrix.« less

Performance evaluation of rotating pump jet mixing of radioactive wastes in Hanford Tanks 241-AP-102 and -104

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onishi, Y.; Recknagle, K.P.

The purpose of this study was to confirm the adequacy of a single mixer pump to fully mix the wastes that will be stored in Tanks 241-AP-102 and -104. These Hanford double-shell tanks (DSTs) will be used as staging tanks to receive low-activity wastes from other Hanford storage tanks and, in turn, will supply the wastes to private waste vitrification facilities for eventual solidification. The TEMPEST computer code was applied to Tanks AP-102 and -104 to simulate waste mixing generated by the 60-ft/s rotating jets and to determine the effectiveness of the single rotating pump to mix the waste. TEMPESTmore » simulates flow and mass/heat transport and chemical reactions (equilibrium and kinetic reactions) coupled together. Section 2 describes the pump jet mixing conditions the authors evaluated, the modeling cases, and their parameters. Section 3 reports model applications and assessment results. The summary and conclusions are presented in Section 4, and cited references are listed in Section 5.« less

New Products.

ERIC Educational Resources Information Center

TechTrends, 1992

1992-01-01

Reviews new educational technology products, including a microcomputer-based tutoring system, laser barcode reader, video/data projectors, CD-ROM for notebook computers, a system to increase a printer's power, data cartridge storage shell, knowledge-based decision tool, video illustrator, interactive videodiscs, surge protectors, scanner system,…

Multishelled NiO Hollow Microspheres for High-performance Supercapacitors with Ultrahigh Energy Density and Robust Cycle Life

NASA Astrophysics Data System (ADS)

Qi, Xinhong; Zheng, Wenji; Li, Xiangcun; He, Gaohong

2016-09-01

Multishelled NiO hollow microspheres for high-performance supercapacitors have been prepared and the formation mechanism has been investigated. By using resin microspheres to absorb Ni2+ and subsequent proper calcinations, the shell numbers, shell spacing and exterior shell structure were facilely controlled via varying synthetic parameters. Particularly, the exterior shell structure that accurately associated with the ion transfer is finely controlled by forming a single shell or closed exterior double-shells. Among multishelled NiO hollow microspheres, the triple-shelled NiO with an outer single-shelled microspheres show a remarkable capacity of 1280 F g-1 at 1 A g-1, and still keep a high value of 704 F g-1 even at 20 A g-1. The outstanding performances are attributed to its fast ion/electron transfer, high specific surface area and large shell space. The specific capacitance gradually increases to 108% of its initial value after 2500 cycles, demonstrating its high stability. Importantly, the 3S-NiO-HMS//RGO@Fe3O4 asymmetric supercapacitor shows an ultrahigh energy density of 51.0 Wh kg-1 at a power density of 800 W kg-1, and 78.8% capacitance retention after 10,000 cycles. Furthermore, multishelled NiO can be transferred into multishelled Ni microspheres with high-efficient H2 generation rate of 598.5 mL H2 min-1 g-1Ni for catalytic hydrolysis of NH3BH3 (AB).

A deep-sea agglutinated foraminifer tube constructed with planktonic foraminifer shells of a single species

NASA Astrophysics Data System (ADS)

Pearson, Paul N.; Expedition 363 Shipboard Scientific Party, IODP

2018-01-01

Agglutinated foraminifera are marine protists that show apparently complex behaviour in constructing their shells, involving selecting suitable sedimentary grains from their environment, manipulating them in three dimensions, and cementing them precisely into position. Here we illustrate a striking and previously undescribed example of complex organisation in fragments of a tube-like foraminifer (questionably assigned to Rhabdammina) from 1466 m water depth on the northwest Australian margin. The tube is constructed from well-cemented siliciclastic grains which form a matrix into which hundreds of planktonic foraminifer shells are regularly spaced in apparently helical bands. These shells are of a single species, Turborotalita clarkei, which has been selected to the exclusion of all other bioclasts. The majority of shells are set horizontally in the matrix with the umbilical side upward. This mode of construction, as is the case with other agglutinated tests, seems to require either an extraordinarily selective trial-and-error process at the site of cementation or an active sensory and decision-making system within the cell.

Quantum transport through single and multilayer icosahedral fullerenes

NASA Astrophysics Data System (ADS)

Lovey, Daniel A.; Romero, Rodolfo H.

2013-10-01

We use a tight-binding Hamiltonian and Green functions methods to calculate the quantum transmission through single-wall fullerenes and bilayered and trilayered onions of icosahedral symmetry attached to metallic leads. The electronic structure of the onion-like fullerenes takes into account the curvature and finite size of the fullerenes layers as well as the strength of the intershell interactions depending on to the number of interacting atom pairs belonging to adjacent shells. Misalignment of the symmetry axes of the concentric iscosahedral shells produces breaking of the level degeneracies of the individual shells, giving rise some narrow quasi-continuum bands instead of the localized discrete peaks of the individual fullerenes. As a result, the transmission function for non symmetrical onions is rapidly varying functions of the Fermi energy. Furthermore, we found that most of the features of the transmission through the onions are due to the electronic structure of the outer shell with additional Fano-like antiresonances arising from coupling with or between the inner shells.

Effects of cluster-shell competition and BCS-like pairing in 12C

NASA Astrophysics Data System (ADS)

Matsuno, H.; Itagaki, N.

2017-12-01

The antisymmetrized quasi-cluster model (AQCM) was proposed to describe α-cluster and jj-coupling shell models on the same footing. In this model, the cluster-shell transition is characterized by two parameters, R representing the distance between α clusters and Λ describing the breaking of α clusters, and the contribution of the spin-orbit interaction, very important in the jj-coupling shell model, can be taken into account starting with the α-cluster model wave function. Not only the closure configurations of the major shells but also the subclosure configurations of the jj-coupling shell model can be described starting with the α-cluster model wave functions; however, the particle-hole excitations of single particles have not been fully established yet. In this study we show that the framework of AQCM can be extended even to the states with the character of single-particle excitations. For ^{12}C, two-particle-two-hole (2p2h) excitations from the subclosure configuration of 0p_{3/2} corresponding to a BCS-like pairing are described, and these shell model states are coupled with the three α-cluster model wave functions. The correlation energy from the optimal configuration can be estimated not only in the cluster part but also in the shell model part. We try to pave the way to establish a generalized description of the nuclear structure.

High performance of SDC and GDC core shell type composite electrolytes using methane as a fuel for low temperature SOFC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Irshad, Muneeb; Siraj, Khurram, E-mail: razahussaini786@gmail.com, E-mail: khurram.uet@gmail.com; Javed, Fayyaz

Nanocomposites Samarium doped Ceria (SDC), Gadolinium doped Ceria (GDC), core shell SDC amorphous Na{sub 2}CO{sub 3} (SDCC) and GDC amorphous Na{sub 2}CO{sub 3} (GDCC) were synthesized using co-precipitation method and then compared to obtain better solid oxide electrolytes materials for low temperature Solid Oxide Fuel Cell (SOFCs). The comparison is done in terms of structure, crystallanity, thermal stability, conductivity and cell performance. In present work, XRD analysis confirmed proper doping of Sm and Gd in both single phase (SDC, GDC) and dual phase core shell (SDCC, GDCC) electrolyte materials. EDX analysis validated the presence of Sm and Gd in bothmore » single and dual phase electrolyte materials; also confirming the presence of amorphous Na{sub 2}CO{sub 3} in SDCC and GDCC. From TGA analysis a steep weight loss is observed in case of SDCC and GDCC when temperature rises above 725 °C while SDC and GDC do not show any loss. The ionic conductivity and cell performance of single phase SDC and GDC nanocomposite were compared with core shell GDC/amorphous Na{sub 2}CO{sub 3} and SDC/ amorphous Na{sub 2}CO{sub 3} nanocomposites using methane fuel. It is observed that dual phase core shell electrolytes materials (SDCC, GDCC) show better performance in low temperature range than their corresponding single phase electrolyte materials (SDC, GDC) with methane fuel.« less

Evaluation of Hanford Single-Shell Waste Tanks Suspected of Water Intrusion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feero, Amie J.; Washenfelder, Dennis J.; Johnson, Jeremy M.

2013-11-14

Intrusions evaluations for twelve single-shell tanks were completed in 2013. The evaluations consisted of remote visual inspections, data analysis, and calculations of estimated intrusion rates. The observation of an intrusion or the preponderance of evidence confirmed that six of the twelve tanks evaluated had intrusions. These tanks were tanks 241-A-103, BX-101, BX-103, BX-110, BY-102, and SX-106.

A nonventing cooling system for space environment extravehicular activity, using radiation and regenerable thermal storage

NASA Technical Reports Server (NTRS)

Bayes, Stephen A.; Trevino, Luis A.; Dinsmore, Craig E.

1988-01-01

This paper outlines the selection, design, and testing of a prototype nonventing regenerable astronaut cooling system for extravehicular activity space suit applications, for mission durations of four hours or greater. The selected system consists of the following key elements: a radiator assembly which serves as the exterior shell of the portable life support subsystem backpack; a layer of phase change thermal storage material, n-hexadecane paraffin, which acts as a regenerable thermal capacitor; a thermoelectric heat pump; and an automatic temperature control system. The capability for regeneration of thermal storage capacity with and without the aid of electric power is provided.

Origin and diversity of testate amoebae shell composition: Example of Bullinularia indica living in Sphagnum capillifolium.

PubMed

Delaine, Maxence; Bernard, Nadine; Gilbert, Daniel; Recourt, Philippe; Armynot du Châtelet, Eric

2017-06-01

Testate amoebae are free-living shelled protists that build a wide range of shells with various sizes, shapes, and compositions. Recent studies showed that xenosomic testate amoebae shells could be indicators of atmospheric particulate matter (PM) deposition. However, no study has yet been conducted to assess the intra-specific mineral, organic, and biologic grain diversity of a single xenosomic species in a natural undisturbed environment. This study aims at providing new information about grain selection to develop the potential use of xenosomic testate amoebae shells as bioindicators of the multiple-origin mineral/organic diversity of their proximal environment. To fulfil these objectives, we analysed the shell content of 38 Bullinularia indica individuals, a single xenosomic testate amoeba species living in Sphagnum capillifolium, by scanning electron microscope (SEM) coupled with X-ray spectroscopy. The shells exhibited high diversities of mineral, organic, and biomineral grains, which confirms their capability to recycle xenosomes. Mineral grain diversity and size of B. indica matched those of the atmospheric natural mineral PM deposited in the peatbog. Calculation of grain size sorting revealed a discrete selection of grains agglutinated by B. indica. These results are a first step towards understanding the mechanisms of particle selection by xenosomic testate amoebae in natural conditions. Copyright © 2017 Elsevier GmbH. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Sheng-Heng; Chang, Chi-Hao; Manthiram, Arumugam

Sulfur is an appealing cathode material for establishing advanced lithium batteries as it offers a high theoretical capacity of 1675 mA h g -1 at low material and operating costs. However, the lithium–sulfur (Li–S) electrochemical cells face several formidable challenges arising from both the materials chemistry (e.g., low electrochemical utilization of sulfur and severe polysulfide diffusion) and battery chemistry (e.g., dynamic and static instability and low sulfur loadings). Here in this study, we present the design of a core–shell cathode with a pure sulfur core shielded within a conductive shell-shaped electrode. The new electrode configuration allows Li–S cells to loadmore » with a high amount of sulfur (sulfur loadings of up to 30 mg cm -2 and sulfur content approaching 70 wt%). The core–shell cathodes demonstrate a superior dynamic and static electrochemical stability in Li–S cells. The high-loading cathodes exhibit (i) a high sulfur utilization of up to 97% at C/20–C/2 rates and (ii) a low self-discharge during long-term cell storage for a three-month rest period and at different cell-storage conditions. Finally, a polysulfide-trap cell configuration is designed to evidence the eliminations of polysulfide diffusion and to investigate the relationship between the electrode configuration and electrochemical characteristics. Finally, the comprehensive analytical results based on the high-loading cathodes suggest that (i) the core–shell cathode is a promising solution for designing highly reversible Li–S cells and (ii) the polysulfide-trap cell configuration is a viable approach to qualitatively evaluating the presence or absence of polysulfide diffusion.« less

Supplemental design requirements document, Multifunction Waste Tank Facility, Project W-236A. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groth, B.D.

The Multi-Function Waste Tank Facility (MWTF) consists of four, nominal 1 million gallon, underground double-shell tanks, located in the 200-East area, and two tanks of the same capacity in the 200-West area. MWTF will provide environmentally safe storage capacity for wastes generated during remediation/retrieval activities of existing waste storage tanks. This document delineates in detail the information to be used for effective implementation of the Functional Design Criteria requirements.

A new near-linear scaling, efficient and accurate, open-shell domain-based local pair natural orbital coupled cluster singles and doubles theory.

PubMed

Saitow, Masaaki; Becker, Ute; Riplinger, Christoph; Valeev, Edward F; Neese, Frank

2017-04-28

The Coupled-Cluster expansion, truncated after single and double excitations (CCSD), provides accurate and reliable molecular electronic wave functions and energies for many molecular systems around their equilibrium geometries. However, the high computational cost, which is well-known to scale as O(N 6 ) with system size N, has limited its practical application to small systems consisting of not more than approximately 20-30 atoms. To overcome these limitations, low-order scaling approximations to CCSD have been intensively investigated over the past few years. In our previous work, we have shown that by combining the pair natural orbital (PNO) approach and the concept of orbital domains it is possible to achieve fully linear scaling CC implementations (DLPNO-CCSD and DLPNO-CCSD(T)) that recover around 99.9% of the total correlation energy [C. Riplinger et al., J. Chem. Phys. 144, 024109 (2016)]. The production level implementations of the DLPNO-CCSD and DLPNO-CCSD(T) methods were shown to be applicable to realistic systems composed of a few hundred atoms in a routine, black-box fashion on relatively modest hardware. In 2011, a reduced-scaling CCSD approach for high-spin open-shell unrestricted Hartree-Fock reference wave functions was proposed (UHF-LPNO-CCSD) [A. Hansen et al., J. Chem. Phys. 135, 214102 (2011)]. After a few years of experience with this method, a few shortcomings of UHF-LPNO-CCSD were noticed that required a redesign of the method, which is the subject of this paper. To this end, we employ the high-spin open-shell variant of the N-electron valence perturbation theory formalism to define the initial guess wave function, and consequently also the open-shell PNOs. The new PNO ansatz properly converges to the closed-shell limit since all truncations and approximations have been made in strict analogy to the closed-shell case. Furthermore, given the fact that the formalism uses a single set of orbitals, only a single PNO integral transformation is necessary, which offers large computational savings. We show that, with the default PNO truncation parameters, approximately 99.9% of the total CCSD correlation energy is recovered for open-shell species, which is comparable to the performance of the method for closed-shells. UHF-DLPNO-CCSD shows a linear scaling behavior for closed-shell systems, while linear to quadratic scaling is obtained for open-shell systems. The largest systems we have considered contain more than 500 atoms and feature more than 10 000 basis functions with a triple-ζ quality basis set.

A new near-linear scaling, efficient and accurate, open-shell domain-based local pair natural orbital coupled cluster singles and doubles theory

NASA Astrophysics Data System (ADS)

Saitow, Masaaki; Becker, Ute; Riplinger, Christoph; Valeev, Edward F.; Neese, Frank

2017-04-01

The Coupled-Cluster expansion, truncated after single and double excitations (CCSD), provides accurate and reliable molecular electronic wave functions and energies for many molecular systems around their equilibrium geometries. However, the high computational cost, which is well-known to scale as O(N6) with system size N, has limited its practical application to small systems consisting of not more than approximately 20-30 atoms. To overcome these limitations, low-order scaling approximations to CCSD have been intensively investigated over the past few years. In our previous work, we have shown that by combining the pair natural orbital (PNO) approach and the concept of orbital domains it is possible to achieve fully linear scaling CC implementations (DLPNO-CCSD and DLPNO-CCSD(T)) that recover around 99.9% of the total correlation energy [C. Riplinger et al., J. Chem. Phys. 144, 024109 (2016)]. The production level implementations of the DLPNO-CCSD and DLPNO-CCSD(T) methods were shown to be applicable to realistic systems composed of a few hundred atoms in a routine, black-box fashion on relatively modest hardware. In 2011, a reduced-scaling CCSD approach for high-spin open-shell unrestricted Hartree-Fock reference wave functions was proposed (UHF-LPNO-CCSD) [A. Hansen et al., J. Chem. Phys. 135, 214102 (2011)]. After a few years of experience with this method, a few shortcomings of UHF-LPNO-CCSD were noticed that required a redesign of the method, which is the subject of this paper. To this end, we employ the high-spin open-shell variant of the N-electron valence perturbation theory formalism to define the initial guess wave function, and consequently also the open-shell PNOs. The new PNO ansatz properly converges to the closed-shell limit since all truncations and approximations have been made in strict analogy to the closed-shell case. Furthermore, given the fact that the formalism uses a single set of orbitals, only a single PNO integral transformation is necessary, which offers large computational savings. We show that, with the default PNO truncation parameters, approximately 99.9% of the total CCSD correlation energy is recovered for open-shell species, which is comparable to the performance of the method for closed-shells. UHF-DLPNO-CCSD shows a linear scaling behavior for closed-shell systems, while linear to quadratic scaling is obtained for open-shell systems. The largest systems we have considered contain more than 500 atoms and feature more than 10 000 basis functions with a triple-ζ quality basis set.

Double-label immunofluorescence method for simultaneous detection of adenovirus and herpes simplex virus from the eye.

PubMed

Walpita, P; Darougar, S

1989-07-01

The development and application of a double-label immunofluorescence method which has the potential to screen for single or dual infections from any site, in single shell vial cultures, is described. In this study, a total of 1,141 ocular specimens were inoculated in shell vials, centrifuged at 15,000 X g for 1 h, incubated at 37 degrees C for 48 h, and fixed in methanol at room temperature for 15 min. The virus inclusions were detected by staining with a double-label indirect immunofluorescence procedure using mixtures of appropriate first antibodies, followed by fluorescein- and rhodamine-conjugated second antibodies. Each specimen was also inoculated in parallel by the conventional virus isolation method. The sensitivity and specificity of the double-label shell vial procedure were comparable to those with the conventional method, and the former test took only 48 h to complete. The test offers a rapid and simple single-vial procedure which allows for individual or simultaneous detection of multiple pathogens. It results in savings in time and cost over the conventional virus isolation method and other shell vial procedures.

The fractal dimension of cell membrane correlates with its capacitance: A new fractal single-shell model

PubMed Central

Wang, Xujing; Becker, Frederick F.; Gascoyne, Peter R. C.

2010-01-01

The scale-invariant property of the cytoplasmic membrane of biological cells is examined by applying the Minkowski–Bouligand method to digitized scanning electron microscopy images of the cell surface. The membrane is found to exhibit fractal behavior, and the derived fractal dimension gives a good description of its morphological complexity. Furthermore, we found that this fractal dimension correlates well with the specific membrane dielectric capacitance derived from the electrorotation measurements. Based on these findings, we propose a new fractal single-shell model to describe the dielectrics of mammalian cells, and compare it with the conventional single-shell model (SSM). We found that while both models fit with experimental data well, the new model is able to eliminate the discrepancy between the measured dielectric property of cells and that predicted by the SSM. PMID:21198103

CHANGES IN THE MICROFLORA OF HADDOCK FILLETS AND SHUCKED SOFT-SHELLED CLAMS AFTER IRRADIATION WITH Co$sup 60$ GAMMA RAYS AND STORAGE TO 0 C AND 6 C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Masurovsky, E.B.; Voss, J.S.; Goldblith, S.A.

1963-05-01

Microbiologic analyses were made on haddock fillets and shucked soft- shelled clams before and after treatment with doses of from 50000 to 800000 rad of Co/sup 60/ gamma rays. A decided change occurred in the constitution of the microbial populations of both products: from a mixed gram-negativegram-positive flora to a predominantly gram-positive flora immediately after irradiation. The majority of these surviving microorganisms were micrococci, spore-forming bacilli, yeasts, molds, and actinomyces. During storage at refrigeration temperatures above freezing, the microflora changed from the more radioresistant gram-positive species to the more prolific gram-negative psychrophilic species that flourish at low temperatures. Micrococci andmore » gram-positive rods declined somewhat during the rise of the actively proteolytic-lipolytic pseudomonads and related species, but still remained at high enough levels to contribute significantly to the spoilage observed at different times in storage. The eventual spoilage of haddock fillets was characterized by discoloration with water-soluble yellow, green, and red bacterial pigments; degradation of the tissue, by proteolytic and other microbial enzymes; and formation of volatile compounds that smelled putrid, rancid, and generally foul and pungent. Shucked soft-shelled clams displayed a different spoilage pattern, changing to a gelatinous mass with stale, acrid, putrid, sulfurous odor. These differences are attributable to the varied biochemical nature of the tissues involved, the Eh potential within the tissues, the time sequence of microfloral change, and the species and types of microorganisms associated with each product. Staphylococci were present in small numbers, but did not appear to be species of public health significance. Gram-negative enteric rods were also encountered, but were considered to be of doubtful public health importance. (BBB)« less

NRC approves spent-fuel cask for general use: Who needs Yucca Mountain?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simpson, J.

1993-07-01

The Nuclear Regulatory Commission (NRC) on April 7, 1993, added Pacific Sierra Nuclear Associates`s (PSNA`s) VSC-24 spent-fuel container to its list of approved storage casks. Unlike previously approved designs, however, the cask was made available for use by utilities without site-specific approval. The VSC-24 (ventilated storage cask) is a 130-ton, 16-foot high vertical storage container composed of a ventilated concrete cask (VCC) housing a steel multi-assembly sealed basket (MSB). A third component, a transfer cask (MTC), shields, supports, and protects the MSB during fuel loading and VCC loading operations. The VCC is a cylindrical reinforced-concrete cask 29 inches thick, withmore » a 1.75-inch-thick A 36 steel liner. The cask contains eight vents-four on the top and four on the bottom-to provide for MSB (and fuel rod) cooling. Its concrete shell provides protection against shearing and penetration by tornado projectiles, protects the MSB in the event of a drop or tipover, and is designed to withstand internal temperatures of 350 degrees Farenheit. The VCC is closed with a bolted-down cover of 0.75-inch-thick A 36 steel. The MSB, which provides the primary boundary for 24 spent fuel rods, is a cylindrical steel shell with a thick shield plug and steel cover plates welded at each end. The shell and covers are constructed from SA 516 Grade 70 pressure vessel steel. Fuel is housed in a basket fabricated from SA 516 Grade 70 sheet steel. Penetrations in the MSB`s structural and shield lids allow for vacuum drying and backfilling with helium after fuel loading. Although its manufacturer claims a design life of 50 years, the NRC has licensed the VSC-24 cask for 20 years.« less

Role of N-methyl-2-pyrrolidone for preparation of Fe3O4@SiO2 controlled the shell thickness

NASA Astrophysics Data System (ADS)

Wee, Sung-Bok; Oh, Hyeon-Cheol; Kim, Tae-Gyun; An, Gye-Seok; Choi, Sung-Churl

2017-04-01

We developed a simple and novel approach for the synthesis of Fe3O4@SiO2 nanoparticles with controlled shell thickness, and studied the mechanism. The introduction of N-methyl-2-pyrrolidone (NMP) led to trapping of monomer nuclei in single shell and controlled the shell thickness. Fe3O4@SiO2 controlled the shell thickness, showing a high magnetization value (64.47 emu/g). Our results reveal the role and change in the chemical structure of NMP during the core-shell synthesis process. NMP decomposed to 4-aminobutanoic acid in alkaline condition and decreased the hydrolysis rate of the silica coating process.

Porous yolk-shell microspheres as N-doped carbon matrix for motivating the oxygen reduction activity of oxygen evolution oriented materials.

PubMed

Zhou, Jinqiu; Wang, Mengfan; Qian, Tao; Liu, Sisi; Cao, Xuecheng; Yang, Tingzhou; Yang, Ruizhi; Yan, Chenglin

2017-09-08

It is highly challenging to explore high-performance bi-functional oxygen electrode catalysts for their practical application in next-generation energy storage and conversion devices. In this work, we synthesize hierarchical N-doped carbon microspheres with porous yolk-shell structure (NCYS) as a metal-free electrocatalyst toward efficient oxygen reduction through a template-free route. The enhanced oxygen reduction performances in both alkaline and acid media profit well from the porous yolk-shell structure as well as abundant nitrogen functional groups. Furthermore, such yolk-shell microspheres can be used as precursor materials to motivate the oxygen reduction activity of oxygen evolution oriented materials to obtain a desirable bi-functional electrocatalyst. To verify its practical utility, Zn-air battery tests are conducted and exhibit satisfactory performance, indicating that this constructed concept for preparation of bi-functional catalyst will afford a promising strategy for exploring novel metal-air battery electrocatalysts.

Porous yolk-shell microspheres as N-doped carbon matrix for motivating the oxygen reduction activity of oxygen evolution oriented materials

NASA Astrophysics Data System (ADS)

Zhou, Jinqiu; Wang, Mengfan; Qian, Tao; Liu, Sisi; Cao, Xuecheng; Yang, Tingzhou; Yang, Ruizhi; Yan, Chenglin

2017-09-01

It is highly challenging to explore high-performance bi-functional oxygen electrode catalysts for their practical application in next-generation energy storage and conversion devices. In this work, we synthesize hierarchical N-doped carbon microspheres with porous yolk-shell structure (NCYS) as a metal-free electrocatalyst toward efficient oxygen reduction through a template-free route. The enhanced oxygen reduction performances in both alkaline and acid media profit well from the porous yolk-shell structure as well as abundant nitrogen functional groups. Furthermore, such yolk-shell microspheres can be used as precursor materials to motivate the oxygen reduction activity of oxygen evolution oriented materials to obtain a desirable bi-functional electrocatalyst. To verify its practical utility, Zn-air battery tests are conducted and exhibit satisfactory performance, indicating that this constructed concept for preparation of bi-functional catalyst will afford a promising strategy for exploring novel metal-air battery electrocatalysts.

Morphology of the ferritin iron core by aberration corrected scanning transmission electron microscopy

NASA Astrophysics Data System (ADS)

Jian, Nan; Dowle, Miriam; Horniblow, Richard D.; Tselepis, Chris; Palmer, Richard E.

2016-11-01

As the major iron storage protein, ferritin stores and releases iron for maintaining the balance of iron in fauna, flora, and bacteria. We present an investigation of the morphology and iron loading of ferritin (from equine spleen) using aberration-corrected high angle annular dark field scanning transmission electron microscopy. Atom counting method, with size selected Au clusters as mass standards, was employed to determine the number of iron atoms in the nanoparticle core of each ferritin protein. Quantitative analysis shows that the nuclearity of iron atoms in the mineral core varies from a few hundred iron atoms to around 5000 atoms. Moreover, a relationship between the iron loading and iron core morphology is established, in which mineral core nucleates from a single nanoparticle, then grows along the protein shell before finally forming either a solid or hollow core structure.

A Phase-Separation Route to Synthesize Porous CNTs with Excellent Stability for Na+ Storage.

PubMed

Chen, Zhi; Wang, Taihong; Zhang, Ming; Cao, Guozhong

2017-06-01

Porous carbon nanotubes (CNTs) are obtained by removing MoO 2 nanoparticles from MoO 2 @C core@shell nanofibers which are synthesized by phase-segregation via a single-needle electrospinning method. The specific surface area of porous CNTs is 502.9 m 2 g -1 , and many oxygen-containing functional groups (COH, CO) are present. As anodes for sodium-ion batteries, the porous CNT electrode displays excellent rate performance and cycling stability (110 mA h g -1 after 1200 cycles at 5 A g -1 ). Those high properties can be attributed to the porous structure and surface modification to steadily store Na + with high capacity. The work provides a facile and broadly applicable way to fabricate the porous CNTs and their composites for batteries, catalysts, and fuel cells. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Engineering report single-shell tank farms interim measures to limit infiltration through the vadose zone

DOE Office of Scientific and Technical Information (OSTI.GOV)

HAASS, C.C.

1999-10-14

Identifies, evaluates and recommends interim measures for reducing or eliminating water sources and preferential pathways within the vadose zone of the single-shell tank farms. Features studied: surface water infiltration and leaking water lines that provide recharge moisture, and wells that could provide pathways for contaminant migration. An extensive data base, maps, recommended mitigations, and rough order of magnitude costs are included.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez, John A.; Henderson, Thomas M.; Scuseria, Gustavo E.

Restricted single-reference coupled cluster theory truncated to single and double excitations accurately describes weakly correlated systems, but often breaks down in the presence of static or strong correlation. Good coupled cluster energies in the presence of degeneracies can be obtained by using a symmetry-broken reference, such as unrestricted Hartree-Fock, but at the cost of good quantum numbers. A large body of work has shown that modifying the coupled cluster ansatz allows for the treatment of strong correlation within a single-reference, symmetry-adapted framework. The recently introduced singlet-paired coupled cluster doubles (CCD0) method is one such model, which recovers correct behavior formore » strong correlation without requiring symmetry breaking in the reference. Here, we extend singlet-paired coupled cluster for application to open shells via restricted open-shell singlet-paired coupled cluster singles and doubles (ROCCSD0). The ROCCSD0 approach retains the benefits of standard coupled cluster theory and recovers correct behavior for strongly correlated, open-shell systems using a spin-preserving ROHF reference.« less

Electrochemical and in situ spectroscopic studies of materials of relevance to energy storage and electrocatalysis

NASA Astrophysics Data System (ADS)

Mo, Yibo

In situ X-ray absorption (XAS), surface enhanced Raman spectroscopy (SERS) and rotating ring disk electrode techniques have been employed for the characterization of materials of relevance to electrochemical energy storage and electrocatalysis. In particular, analysis of in situ Ir LIII-edge extended X-ray absorption fine structure (EXAFS) of IrO2 films electrodeposited on Au substrates yielded Ir-O bond lengths decreasing in the sequence 2.02, 1.97 and 1.93 A, for Ir3+, Ir4+ and Ir5+ sites, respectively. Although features consistent with the presence of crystalline IrO2 in the highly hydrated films were found from in situ SERS, the lack of intense shells in the FT of the EXAFS function beyond the nearest oxygen neighbors indicates that the films by and large do not display long range order. In similar studies, the Fourier transform of the k3-weighted Ru K-edge EXAFS of electrodeposited RuO2 films recorded in situ were characterized by two shells attributed to Ru-O and Ru-Ru interactions at 1.94(1) and 3.12(2) A, in agreement with results obtained ex situ for Ru4+ in hydrous RuO2, whereas films in the reduced state yielded a single Ru-O interaction shell at 2.02(1) A. Extensions of these in situ XAS to the study of electrocatalysts for the nitrite reduction made it possible to identify and characterize the electronic and structural properties of a nitrosyl iron porphyrin adduct adsorbed on an electrode surface via the analysis of Fe K-edge XAS data. The effects of Se and S ad-atoms on the electrocatalytic activity of Pt electrodes have been examined using RRDE techniques. In acid, within a rather narrow range of coverages, both S- and Se-modified Pt surfaces promote the 2-electron reduction of dioxygen to hydrogen peroxide at ca. 100% faradaic efficiency over a wide potential region. Also developed were methods for immobilizing unsupported dispersed high area Pt particles a glassy carbon (GC) disk of a rotating Pt(ring)/GC(disk) electrode assembly allowing electrochemical measurements to be performed under forced convection with only minimal losses of Pt from the surface.

Microencapsulation in Alginate and Chitosan Microgels to Enhance Viability of Bifidobacterium longum for Oral Delivery

PubMed Central

Yeung, Timothy W.; Üçok, Elif F.; Tiani, Kendra A.; McClements, David J.; Sela, David A.

2016-01-01

Probiotic microorganisms are incorporated into a wide variety of foods, supplements, and pharmaceuticals to promote human health and wellness. However, maintaining bacterial cell viability during storage and gastrointestinal transit remains a challenge. Encapsulation of bifidobacteria within food-grade hydrogel particles potentially mitigates their sensitivity to environmental stresses. In this study, Bifidobacterium longum subspecies and strains were encapsulated in core-shell microgels consisting of an alginate core and a microgel shell. Encapsulated obligate anaerobes Bifidobacterium longum subsp. infantis and Bifidobacterium longum subsp. longum exhibited differences in viability in a strain-dependent manner, without a discernable relationship to subspecies lineage. This includes viability under aerobic storage conditions and modeled gastrointestinal tract conditions. Coating alginate microgels with chitosan did not improve viability compared to cells encapsulated in alginate microgels alone, suggesting that modifying the surface charge alone does not enhance delivery. Thus hydrogel beads have great potential for improving the stability and efficacy of bifidobacterial probiotics in various nutritional interventions. PMID:27148184

Multishelled NiO Hollow Microspheres for High-performance Supercapacitors with Ultrahigh Energy Density and Robust Cycle Life

PubMed Central

Qi, Xinhong; Zheng, Wenji; Li, Xiangcun; He, Gaohong

2016-01-01

Multishelled NiO hollow microspheres for high-performance supercapacitors have been prepared and the formation mechanism has been investigated. By using resin microspheres to absorb Ni2+ and subsequent proper calcinations, the shell numbers, shell spacing and exterior shell structure were facilely controlled via varying synthetic parameters. Particularly, the exterior shell structure that accurately associated with the ion transfer is finely controlled by forming a single shell or closed exterior double-shells. Among multishelled NiO hollow microspheres, the triple-shelled NiO with an outer single-shelled microspheres show a remarkable capacity of 1280 F g−1 at 1 A g−1, and still keep a high value of 704 F g−1 even at 20 A g−1. The outstanding performances are attributed to its fast ion/electron transfer, high specific surface area and large shell space. The specific capacitance gradually increases to 108% of its initial value after 2500 cycles, demonstrating its high stability. Importantly, the 3S-NiO-HMS//RGO@Fe3O4 asymmetric supercapacitor shows an ultrahigh energy density of 51.0 Wh kg−1 at a power density of 800 W kg−1, and 78.8% capacitance retention after 10,000 cycles. Furthermore, multishelled NiO can be transferred into multishelled Ni microspheres with high-efficient H2 generation rate of 598.5 mL H2 min−1 g−1Ni for catalytic hydrolysis of NH3BH3 (AB). PMID:27616420

Modeling X-Ray Photoionized Plasmas: Ion Storage Ring Measurements of Low Temperature Dielectronic Recombination Rate Coefficients for L-Shell Iron

NASA Technical Reports Server (NTRS)

Savin, D. W.; Badnell, N. R.; Bartsch, T.; Brandau, C.; Chen, M. H.; Grieser, M.; Gwinner, G.; Hoffknecht, A.; Kahn, S. M.; Linkemann, J.

2000-01-01

Iron L-shell ions (Fe XVII to Fe XXIV) play an important role in determining the line emission and thermal and ionization structures of photoionized gases. Existing uncertainties in the theoretical low temperature dielectronic recombination (DR) rate coefficients for these ions significantly affects our ability to model and interpret observations of photoionized plasmas. To help address this issue, we have initiated a laboratory program to produce reliable low temperature DR rates. Here, we present some of our recent results and discuss some of their astrophysical implications.

A computer program for analyzing unresolved Mossbauer hyperfine spectra

NASA Technical Reports Server (NTRS)

Schiess, J. R.; Singh, J. J.

1978-01-01

The program for analyzing unresolved Mossbauer hyperfine spectra was written in FORTRAN 4 language for the Control Data CYBER 170 series digital computer system with network operating system 1.1. With the present dimensions, the program requires approximately 36,000 octal locations of core storage. A typical case involving two innermost coordination shells in which the amplitudes and the peak positions of all three components were estimated in 25 iterations requires 30 seconds on CYBER 173. The program was applied to determine the effects of various near neighbor impurity shells on hyperfine fields in dilute FeAl alloys.

Three-Point Bending Fracture Behavior of Single Oriented Crossed-Lamellar Structure in Scapharca broughtonii Shell

PubMed Central

Ji, Hong-Mei; Zhang, Wen-Qian; Wang, Xu; Li, Xiao-Wu

2015-01-01

The three-point bending strength and fracture behavior of single oriented crossed-lamellar structure in Scapharca broughtonii shell were investigated. The samples for bending tests were prepared with two different orientations perpendicular and parallel to the radial ribs of the shell, which corresponds to the tiled and stacked directions of the first-order lamellae, respectively. The bending strength in the tiled direction is approximately 60% higher than that in the stacked direction, primarily because the regularly staggered arrangement of the second-order lamellae in the tiled direction can effectively hinder the crack propagation, whereas the cracks can easily propagate along the interfaces between lamellae in the stacked direction. PMID:28793557

Enceladus's south polar thermal anomaly in light of weak thermal convection

NASA Astrophysics Data System (ADS)

Besserer, Jonathan; Golabek, Gregor J.; Rozel, Antoine; Tackley, Paul J.

2014-05-01

The south polar thermal anomaly of Enceladus, contrasting with older and colder northern regions, suggests an asymmetrical heat transfer in the satellite's ice shell. Most of the current models that explain such a distribution prescribe an a priori asymmetry by mean of a mechanical or topographical anomaly in or below the south polar ice shell. We present here a series of simulations with a 2D-spherical convection model to investigate the possibility of self-consistently generating a localized mechanical anomaly in the ice shell. We focus on the non-Newtonian character of ice rheology, and on the stability of a single-plume (i.e. localized convection) and low-degree convection regimes. We show that the non-Newtonian rheology favors a localized (tidally heated) convection surrounded by a conductive ice mantle, even with a global, liquid water ocean at the base of the ice shell. We find that the single-plume state is very unlikely to remain stable if the rheology is Newtonian. The proposed thermal regime for Enceladus's ice shell is therefore weak, single-plume thermal convection focused at the south pole (e.g., remnant of a formerly more vigorous convection). Such weak-to-sub-critical regimes may be important for icy satellites, as recently pointed out by Solomatov (2012, PEPI). We will discuss the effects of ice plasticity on heat focusing in Enceladus's South Polar Terrain, together with the possibility of an ice shell a factor ~2 thinner than previously thought (Hemingway et al., AGU 2013; Stevenson et al., AGU 2013).

Effect of combination of chitosan coating and irradiation on physicochemical and functional properties of chicken egg during room-temperature storage

NASA Astrophysics Data System (ADS)

Liu, Xian De; Jang, Aera; Kim, Dong Hun; Lee, Bong Duk; Lee, Mooha; Jo, Cheorun

2009-07-01

The effect of combination of chitosan coating and irradiation on quality and storage stability of shell egg was investigated. Salmonella typhimurium inoculated on eggshell was not detected by irradiation of 2.0 kGy at day 0 and/or chitosan coating (1%, pH 5.0) after 3 days of storage. One-day-old fresh chicken egg was chitosan coated and irradiated at 0, 0.5, 1.0, 1.5 and 2.0 kGy by gamma ray. The egg samples were stored at room temperature for 14 days and the effects of the combination treatment on internal physicochemical and functional properties were investigated. The Haugh unit of egg was decreased by irradiation even at 0.5 kGy. Irradiation increased the lipid oxidation in egg yolk at 2 kGy but the egg with chitosan coating reduced the level of lipid oxidation. Irradiation increased the foaming ability of egg white and decreased viscosity of egg yolk and white. Results suggested that combination of irradiation and chitosan coating can improve safety of shell egg but irradiation treatment may reduce the egg quality for direct consumption. However, an improved functional property for further processing and efficient separation of egg white and yolk can be expected for egg processing industry using irradiation.

Structural instability of shell-like assemblies of a keplerate-type polyoxometalate induced by ionic strength.

PubMed

Veen, Sandra J; Kegel, Willem K

2009-11-19

We demonstrate a new structural instability of shell-like assemblies of polyoxometalates. Besides the colloidal instability, that is, the formation of aggregates that consist of many single layered POM-shells, these systems also display an instability on a structural scale within the shell-like assemblies. This instability occurs at significantly lower ionic strength than the colloidal stability limit and only becomes evident after a relatively long time. For the polyoxometalate, abbreviated as {Mo(72)Fe(30)}, it is shown that the structural stability limit of POM-shells lies between a NaCl concentration of 1.00 and 5.00 mM in aqueous solution.

Fast-Response Single-Nanowire Photodetector Based on ZnO/WS2 Core/Shell Heterostructures.

PubMed

Butanovs, Edgars; Vlassov, Sergei; Kuzmin, Alexei; Piskunov, Sergei; Butikova, Jelena; Polyakov, Boris

2018-04-25

The surface plays an exceptionally important role in nanoscale materials, exerting a strong influence on their properties. Consequently, even a very thin coating can greatly improve the optoelectronic properties of nanostructures by modifying the light absorption and spatial distribution of charge carriers. To use these advantages, 1D/1D heterostructures of ZnO/WS 2 core/shell nanowires with a-few-layers-thick WS 2 shell were fabricated. These heterostructures were thoroughly characterized by scanning and transmission electron microscopy, X-ray diffraction, and Raman spectroscopy. Then, a single-nanowire photoresistive device was assembled by mechanically positioning ZnO/WS 2 core/shell nanowires onto gold electrodes inside a scanning electron microscope. The results show that a few layers of WS 2 significantly enhance the photosensitivity in the short wavelength range and drastically (almost 2 orders of magnitude) improve the photoresponse time of pure ZnO nanowires. The fast response time of ZnO/WS 2 core/shell nanowire was explained by electrons and holes sinking from ZnO nanowire into WS 2 shell, which serves as a charge carrier channel in the ZnO/WS 2 heterostructure. First-principles calculations suggest that the interface layer i-WS 2 , bridging ZnO nanowire surface and WS 2 shell, might play a role of energy barrier, preventing the backward diffusion of charge carriers into ZnO nanowire.

Flexible, silver nanowire network nickel hydroxide core-shell electrodes for supercapacitors

NASA Astrophysics Data System (ADS)

Yuksel, Recep; Coskun, Sahin; Kalay, Yunus Eren; Unalan, Husnu Emrah

2016-10-01

We present a novel one-dimensional coaxial architecture composed of silver nanowire (Ag NW) network core and nickel hydroxide (Ni(OH)2) shell for the realization of coaxial nanocomposite electrode materials for supercapacitors. Ag NWs are formed conductive networks via spray coating onto polyethylene terephthalate (PET) substrates and Ni(OH)2 is gradually electrodeposited onto the Ag NW network to fabricate core-shell electrodes for supercapacitors. Synergy of highly conductive Ag NWs and high capacitive Ni(OH)2 facilitate ion and electron transport, enhance electrochemical properties and result in a specific capacitance of 1165.2 F g-1 at a current density of 3 A g-1. After 3000 cycles, fabricated nanocomposite electrodes show 93% capacity retention. The rational design explored in this study points out the potential of nanowire based coaxial energy storage devices.

The Dynamic Response and Vibration of Functionally Graded Carbon Nanotube-Reinforced Composite (FG-CNTRC) Truncated Conical Shells Resting on Elastic Foundations

PubMed Central

Nguyen Dinh, Duc; Nguyen, Pham Dinh

2017-01-01

Based on the classical shell theory, the linear dynamic response of functionally graded carbon nanotube-reinforced composite (FG-CNTRC) truncated conical shells resting on elastic foundations subjected to dynamic loads is presented. The truncated conical shells are reinforced by single-walled carbon nanotubes (SWCNTs) that vary according to the linear functions of the shell thickness. The motion equations are solved by the Galerkin method and the fourth-order Runge–Kutta method. In numerical results, the influences of geometrical parameters, elastic foundations, natural frequency parameters, and nanotube volume fraction of FG-CNTRC truncated conical shells are investigated. The proposed results are validated by comparing them with those of other authors. PMID:29057821

75 FR 18751 - Prevention of Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-13

...-0190] Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation... information: (1) The date by which egg producers must register their farm with FDA, (2) the address and telephone number for requesting copies of Form 3733, and (3) the address to which egg producers must send...

Linguine sign at MR imaging: does it represent the collapsed silicone implant shell?

PubMed

Gorczyca, D P; DeBruhl, N D; Mund, D F; Bassett, L W

1994-05-01

One intact and one ruptured single-lumen implant were surgically placed in a rabbit. Magnetic resonance (MR) imaging was performed before and after surgical removal, and the ruptured implant was imaged after removal of the implant shell. Multiple curvilinear hypointense lines (linguine sign) were present in the MR images of the ruptured implant and of the implant shell alone immersed in saline solution but not in the image of the free silicone. The collapsed implant shell in a ruptured silicone implant does cause the linguine sign.

River Protection Project (RPP) Dangerous Waste Training Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

POHTO, R.E.

2000-03-09

This supporting document contains the training plan for dangerous waste management at River Protection Project TSD Units. This document outlines the dangerous waste training program developed and implemented for all Treatment, Storage, and Disposal (TSD) Units operated by River Protection Project (RPP) in the Hanford 200 East, 200 West and 600 Areas and the <90 Day Accumulation Area at 209E. Operating TSD Units managed by RPP are: the Double-Shell Tank (DST) System, 204-AR Waste Unloading Facility, Grout, and the Single-Shell Tank (SST) System. The program is designed in compliance with the requirements of Washington Administrative Code (WAC) 173-303-330 and Titlemore » 40 Code of Federal Regulations (CFR) 265.16 for the development of a written dangerous waste training program and the Hanford Facility Permit. Training requirements were determined by an assessment of employee duties and responsibilities. The RPP training program is designed to prepare employees to operate and maintain the Tank Farms in a safe, effective, efficient, and environmentally sound manner. In addition to preparing employees to operate and maintain the Tank Farms under normal conditions, the training program ensures that employees are prepared to respond in a prompt and effective manner should abnormal or emergency conditions occur. Emergency response training is consistent with emergency responses outlined in the following Building Emergency Plans: HNF-IP-0263-TF and HNF-=IP-0263-209E.« less

Preparation of hollow mesoporous carbon spheres and their performances for electrochemical applications

NASA Astrophysics Data System (ADS)

Ariyanto, T.; Zhang, G. R.; Kern, A.; Etzold, B. J. M.

2018-03-01

Hollow carbon materials have received intensive attention for energy storage/conversion applications due to their attractive properties of high conductivity, high surface area, large void and short diffusion pathway. In this work, a novel hollow mesoporous material based on carbide-derived carbon (CDC) is presented. CDC is a new class of carbon material synthesized by the selective extraction of metals from metal carbides. With a two-stage extraction procedure of carbides with chlorine, firstly hybrid core-shell carbon particles were synthesized, i.e. mesoporous/graphitic carbon shells covering microporous/amorphous carbon cores. The amorphous cores were then selectively removed from particles by a careful oxidative treatment utilizing its low thermal characters while the more stable carbon shells remained, thus resulting hollow particles. The characterization methods (e.g. N2 sorption, Raman spectroscopy, temperature-programmed oxidation and SEM) proved the successful synthesis of the aspired material. In electric double-layer capacitor (EDLC) testing, this novel hollow core material showed a remarkable enhancement of EDLC’s rate handling ability (75% at a high scan rate) with respect to an entirely solid-mesoporous material. Furthermore, as a fuel cell catalyst support the material showed higher Pt mass activity (a factor of 1.8) compared to a conventional carbon support for methanol oxidation without noticeably decreasing activity in a long-term testing. Therefore, this carbon nanostructure shows great promises as efficient electrode materials for energy storage and conversion systems.

New Approach to Create TiO2(B)/Carbon Core/Shell Nanotubes: Ideal Structure for Enhanced Lithium Ion Storage.

PubMed

Zhu, Xiaoyi; Yang, Xianfeng; Lv, Chunxiao; Guo, Shaojun; Li, Jianjiang; Zheng, Zhanfeng; Zhu, Huaiyong; Yang, Dongjiang

2016-07-27

To achieve uniform carbon coating on TiO2 nanomaterials, high temperature (>500 °C) annealing treatment is a necessity. However, the annealing treatment inevitably leads to the strong phase transformation from TiO2(B) with high lithium ion storage (LIS) capacity to anatase with low LIS one as well as the damage of nanostructures. Herein, we demonstrate a new approach to create TiO2(B)/carbon core/shell nanotubes (C@TBNTs) using a long-chain silane polymethylhydrosiloxane (PMHS) to bind the TBNTs by forming Si-O-Ti bonds. The key feature of this work is that the introduction of PMHS onto TBNTs can afford TBNTs with very high thermal stability at higher than 700 °C and inhibit the phase transformation from TiO2(B) to anatase. Such a high thermal property of PMHS-TBNTs makes them easily coated with highly graphitic carbon shell via CVD process at 700 °C. The as-prepared C@TBNTs deliver outstanding rate capability and electrochemical stability, i.e., reversible capacity above 250 mAh g(-1) at 10 C and a high specific capacity of 479.2 mAh g(-1) after 1000 cycles at 1 C. As far as we know, the LIS performance of our sample is the highest among the previously reported TiO2(B) anode materials.

Toward highly stable solid-state unconventional thin-film battery-supercapacitor hybrid devices: Interfacing vertical core-shell array electrodes with a gel polymer electrolyte

NASA Astrophysics Data System (ADS)

Pandey, Gaind P.; Klankowski, Steven A.; Liu, Tao; Wu, Judy; Li, Jun

2017-02-01

A novel solid-state battery-supercapacitor hybrid device is fabricated for high-performance electrical energy storage using a Si anode and a TiO2 cathode in conjunction with a flexible, solid-like gel polymer electrolyte film as the electrolyte and separator. The electrodes were fabricated as three-dimensional nanostructured vertical arrays by sputtering active materials as conformal shells on vertically aligned carbon nanofibers (VACNFs) which serve as the current collector and structural template. Such nanostructured vertical core-shell array-electrodes enable short Li-ion diffusion path and large pseudocapacitive contribution by fast surface reactions, leading to the hybrid features of batteries and supercapacitors that can provide high specific energy over a wide range of power rates. Due to the improved mechanical stability of the infiltrated composite structure, the hybrid cell shows excellent cycling stability and is able to retain more than 95% of the original capacity after 3500 cycles. More importantly, this solid-state device can stably operate in a temperature range from -20 to 60 °C with a very low self-discharge rate and an excellent shelf life. This solid-state architecture is promising for the development of highly stable thin-film hybrid energy storage devices for unconventional applications requiring largely varied power, wider operation temperature, long shelf-life and higher safety standards.

Efficacy of various protein-based coating on enhancing the shelf life of fresh eggs during storage.

PubMed

Caner, Cengiz; Yüceer, Muhammed

2015-07-01

The effectiveness of various coatings (whey protein isolate [WPI], whey protein concentrate [WPC], zein, and shellac) on functional properties, interior quality, and eggshell breaking strength of fresh eggs were evaluated during storage at 24 °: C for 6 weeks. Coatings and storage time had significant effects on Haugh unit, yolk index, albumen pH, dry matter (DMA), relative whipping capacity (RWC), and albumen viscosity. Uncoated eggs had higher albumen pH (9.56) and weight loss, and lower albumen viscosity (5.73), Haugh unit (HU), and yolk index (YI) during storage. Among the coated eggs, the shellac and zein coated eggs had the highest value of albumen viscosity (27.26 to 26.90), HU (74.10 to 73.61), and YI (44.84 to 44.63) after storage. Shellac (1.44%) was more effective in preventing weight loss than WPC (4.59%), WPI (4.60%), and zein (2.13%) coatings. Uncoated eggs had the higest value (6.71%) of weight lost. All coatings increased shell strength (5.18 to 5.73 for top and 3.58 to 4.71 for bottom) significantly (P < 0.05) compared to the uncoated eggs (4.70 for top and 3.15 for bottom). The functional properties such as albumen DMA (14.50 to 16.66 and 18.97 for uncoated) and albumen RWC (841 to 891 and 475 for uncoated) of fresh eggs can be preserved during storage when they are coated. The shellac and zein coatings were more effective for maintaining the internal quality of fresh eggs during storage. Fourier transform near infrared (FT-NIR) in the 800 to 2500 nm reflection spectra were used to quantify the contents of the fresh eggs at the end of storage. Eggs coated with shellac or zein displayed a higher absorbance at 970 and 1,197 nm respectively (OH vibration of water) compared with those coated with WPI or WPC and the uncoated group at the end of storage. The coatings improved functional properties and also shell strength and could be a viable alternative technology for maintaining the internal quality of eggs during long-term storage. This study highlights the promising use of various coatings to both enhance the functional properties and to reduce the breakage of eggs. © 2015 Poultry Science Association Inc.

Radar attenuation in Europa's ice shell: obstacles and opportunities for constraining shell thickness and thermal structure

NASA Astrophysics Data System (ADS)

Kalousova, Klara; Schroeder, Dustin M.; Soderlund, Krista M.; Sotin, Christophe

2016-10-01

With its strikingly young surface and possibly recent endogenic activity, Europa is one of the most exciting bodies within our Solar System and a primary target for spacecraft exploration. Future missions to Europa are expected to carry ice penetrating radar instruments which are powerful tools to investigate the subsurface thermophysical structure of its ice shell.Several authors have addressed the 'penetration depth' of radar sounders at icy moons, however, the concept and calculation of a single value penetration depth is a potentially misleading simplification since it ignores the thermal and attenuation structure complexity of a realistic ice shell. Here we move beyond the concept of a single penetration depth by exploring the variation in two-way radar attenuation for a variety of potential thermal structures of Europa's ice shell as well as for a low loss and high loss temperature-dependent attenuation model. The possibility to detect brines is also investigated.Our results indicate that: (i) for all ice shell thicknesses investigated (5-30 km), a nominal satellite-borne radar sounder will penetrate between 15% and 100% of the total thickness, (ii) the maximum penetration depth strongly varies laterally with the deepest penetration possible through the cold downwellings, (iii) the direct detection of the ice/ocean interface might be possible for shells of up to 15 km if the radar signal travels through the cold downwelling, (iv) even if the ice/ocean interface is not detected, the penetration through most of the shell could constrain the deep shell structure through the loss of signal, and (v) for all plausible ice shells the two-way attenuation to the eutectic point is ≤30 dB which shows a robust potential for longitudinal investigation of the ice shell's shallow structure.Part of this work has been performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract to NASA. K.K. acknowledges support by the Grant Agency of the Czech Republic through project 15-14263Y.

Implementation plan for underground waste storage tank surveillance and stabilization improvements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dukelow, G.T.; Maupin, V.D.; Mihalik, L.A.

1989-04-01

Several studies have addressed the need to upgrade the methods currently used for surveillance of underground waste storage tanks, particularly single-shell tanks (SST), which are susceptible to leaks and intrusions. Fifty tasks were proposed to enhance the existing surveillance program; however, prudent budget management dictates that only the tasks with the highest potential for success be selected and funded. This plan identifies fourteen inexpensive improvements that may be implemented in less than two years. Recent developments stress the need to complete interim stabilization of these tanks more quickly than now budgeted and to identify methods to salvage or eliminate themore » interstitial liquid left behind after saltwell jet-pumping. The plan calls for the use of available resources to remove saltwell liquid from SSTs as rapidly as possible rather than committing to new surveillance technologies that might not lead to near-term improvements. This plan describes the selection criteria and provides cost estimates and schedules for implementing the recommendations of the task forces. The proposed improvements result in completion of jet-pumping in FY 1994, two years ahead of the current FY 1996 milestone. While the accelerated plan requires more funding in the early years, the total cost will be the same as completing the work in FY 1996.« less

Single- and double- lumen silicone breast implant integrity: prospective evaluation of MR and US criteria.

PubMed

Berg, W A; Caskey, C I; Hamper, U M; Kuhlman, J E; Anderson, N D; Chang, B W; Sheth, S; Zerhouni, E A

1995-10-01

To evaluate the accuracy of magnetic resonance (MR) and ultrasound (US) criteria for breast implant integrity. One hundred twenty-two single-lumen silicone breast implants and 22 bilumen implants were evaluated with surface coil MR imaging and US and surgically removed. MR criteria for implant failure were a collapsed implant shell ("linguine sign"), foci of silicone outside the shell ("noose sign"), and extracapsular gel, US criteria were collapsed shell, low-level echoes within the gel, and "snowstorm" echoes of extracapsular silicone. Among single-lumen implants, MR imaging depicted 39 of 40 ruptures, 14 of 28 with minimal leakage; 49 of 54 intact implants were correctly interpreted. US depicted 26 of 40 ruptured implants, four of 28 with minimal leakage, and 30 of 54 intact implants. Among bilumen implants, MR imaging depicted four of five implants with rupture of both lumina and nine of 10 as intact; US depicted one rupture and helped identify two of 10 as intact. Mammography accurately depicted the status of 29 of 30 bilumen implants with MR imaging correlation. MR imaging depicts implant integrity more accurately than US; neither method reliably depicts minimal leakage with shell collapse. Mammography is useful in screening bilumen implant integrity.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Müller, Alfred; Bernhardt, Dietrich; Borovik, Alexander

Single, double, and triple photoionization of Ne + ions by single photons have been investigated at the synchrotron radiation source PETRA III in Hamburg, Germany. Absolute cross-sections were measured by employing the photon-ion merged-beams technique. Photon energies were between about 840 and 930 eV, covering the range from the lowest-energy resonances associated with the excitation of one single K-shell electron up to double excitations involving one K- and one L-shell electron, well beyond the K-shell ionization threshold. Also, photoionization of neutral Ne was investigated just below the K edge. The chosen photon energy bandwidths were between 32 and 500 meV,more » facilitating the determination of natural line widths. The uncertainty of the energy scale is estimated to be 0.2 eV. For comparison with existing theoretical calculations, astrophysically relevant photoabsorption cross-sections were inferred by summing the measured partial ionization channels. Discussion of the observed resonances in the different final ionization channels reveals the presence of complex Auger-decay mechanisms. The ejection of three electrons from the lowest K-shell-excited Ne + (1s2s 2p 6 2S 1/2) level, for example, requires cooperative interaction of at least four electrons.« less

Metal-Organic Frameworks Derived Porous Core/Shell Structured ZnO/ZnCo2O4/C Hybrids as Anodes for High-Performance Lithium-Ion Battery.

PubMed

Ge, Xiaoli; Li, Zhaoqiang; Wang, Chengxiang; Yin, Longwei

2015-12-09

Metal-organic frameworks (MOFs) derived porous core/shell ZnO/ZnCo2O4/C hybrids with ZnO as a core and ZnCo2O4 as a shell are for the first time fabricated by using core/shell ZnCo-MOF precursors as reactant templates. The unique MOFs-derived core/shell structured ZnO/ZnCo2O4/C hybrids are assembled from nanoparticles of ZnO and ZnCo2O4, with homogeneous carbon layers coated on the surface of the ZnCo2O4 shell. When acting as anode materials for lithium-ion batteries (LIBs), the MOFs-derived porous ZnO/ZnCo2O4/C anodes exhibit outstanding cycling stability, high Coulombic efficiency, and remarkable rate capability. The excellent electrochemical performance of the ZnO/ZnCo2O4/C LIB anodes can be attributed to the synergistic effect of the porous structure of the MOFs-derived core/shell ZnO/ZnCo2O4/C and homogeneous carbon layer coating on the surface of the ZnCo2O4 shells. The hierarchically porous core/shell structure offers abundant active sites, enhances the electrode/electrolyte contact area, provides abundant channels for electrolyte penetration, and also alleviates the structure decomposition induced by Li(+) insertion/extraction. The carbon layers effectively improve the conductivity of the hybrids and thus enhance the electron transfer rate, efficiently prevent ZnCo2O4 from aggregation and disintegration, and partially buffer the stress induced by the volume change during cycles. This strategy may shed light on designing new MOF-based hybrid electrodes for energy storage and conversion devices.

Beyond Yolk–Shell Nanoparticles: Fe 3 O 4 @Fe 3 C Core@Shell Nanoparticles as Yolks and Carbon Nanospindles as Shells for Efficient Lithium Ion Storage

DOE PAGES

Zhang, Jianan; Wang, Kaixi; Xu, Qun; ...

2015-02-25

In order to well address the problems of large volume change and dissolution of Fe 3O 4 nanomaterials during Li + intercalation/extraction, herein we demonstrate a one-step in situ nanospace-confined pyrolysis strategy for robust yolk–shell nanospindles with very sufficient internal void space (VSIVS) for high-rate and long-term lithium ion batteries (LIBs), in which an Fe 3O 4@Fe 3C core@shell nanoparticle is well confined in the compartment of a hollow carbon nanospindle. This structure can not only introduce VSIVS to accommodate volume change of Fe 3O 4 but also afford a dual shell of Fe 3C and carbon to restrict Femore » 3O 4 dissolution, thus providing dual roles for greatly improving the capacity retention. Consequently, Fe 3O 4@Fe 3C–C yolk–shell nanospindles deliver a high reversible capacity of 1128.3 mAh g –1 at even 500 mA g –1, excellent high rate capacity (604.8 mAh g –1 at 2000 mA g –1), and prolonged cycling life (maintaining 1120.2 mAh g –1 at 500 mA g –1 for 100 cycles) for LIBs, which are much better than those of Fe 3O 4@C core@shell nanospindles and Fe 3O 4 nanoparticles. The present Fe 3O 4@Fe 3C–C yolk–shell nanospindles are the most efficient Fe 3O 4-based anode materials ever reported for LIBs.« less

Solar hot water system installed at Days Inn Motel, Jacksonville, Florida

NASA Technical Reports Server (NTRS)

1980-01-01

The solar system was designed to provide 65 percent of the hot water demand. Water in the liquid flat plate collector (900 square feet) system automatically drains into the 1000 gallon lined and vented steel storage tank when the pump is not running. Heat is transferred from storage to Domestic Hot Water (DHW) tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and heat exchanger enables solar heated water to help make up DHW standby losses. All pumps are controlled by differential temperature.

76 FR 16425 - Draft Guidance for Industry: Testing for Salmonella

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-23

... draft guidance does not apply to egg producers and other persons who are covered by FDA's final rule ``Prevention of Salmonella Enteritidis in Shell Eggs During Production, Storage, and Transportation.'' The... eggs) and direct-human-contact animal foods, and the interpretation of test results, when the presence...

21 CFR 118.12 - Enforcement and compliance.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION PRODUCTION, STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.12 Enforcement and....) or by a treatment that achieves at least a 5-log destruction of SE or destroyed by or under the...

21 CFR 118.12 - Enforcement and compliance.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION PRODUCTION, STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.12 Enforcement and....) or by a treatment that achieves at least a 5-log destruction of SE or destroyed by or under the...

21 CFR 118.12 - Enforcement and compliance.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION PRODUCTION, STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.12 Enforcement and....) or by a treatment that achieves at least a 5-log destruction of SE or destroyed by or under the...

Characterization of multifunctional structural capacitors for embedded energy storage

NASA Astrophysics Data System (ADS)

Lin, Yirong; Sodano, Henry A.

2009-12-01

Multifunctional composites are a class of materials that combine structural and other functionalities such as sensing, actuation, energy harvesting, and vibration control in order to maximize structural performance while minimizing weight and complexity. Among all the multifunctional composites developed so far, piezoelectric composites have been widely studied due to the high coupling of energy between the electrical and mechanical domains and the inherently high dielectric constant. Several piezoelectric fiber composites have been developed for sensing and actuation applications; however, none of the previously studied composites fully embed all components of an energy storage device as load bearing members of the structure. A multifunctional fiber that can be embedded in a composite material to perform sensing and actuation has been recently developed [Y. Lin and H. A. Sodano, Adv. Funct. Mater. 18, 592 (2008)], in addition to providing load bearing functionality. The design was achieved by coating a common structural fiber, silicon carbide, with a barium titanate piezoelectric shell, and poling the active material radically by employing the structural fiber as one of the electrodes. The silicon carbide core fiber also carries external mechanical loading to protect the brittle barium titanate shell from fracture. The excellent piezoelectric and dielectric properties of the barium titanate material make the active structural fiber an outstanding candidate for converting and storing ambient mechanical energy into electrical energy to power other electric devices in the system. This paper focuses on the characterization of energy storage capability of the multifunctional fiber provided by the dielectric properties of the barium titanate shell. The capacitances of the multifunctional fibers with four different aspect ratios are tested and compared with the theoretical expressions for the cylindrical capacitor, while the breakdown voltages of the multifunctional fibers are tested according to American Society for Testing and Materials standards (ASTM D 149-97a). The stored energy is calculated from the testing results and the best aspect ratio for energy storage application can be determined. The resulting capacitive fiber is shown to have an energy density approximately two orders of magnitude higher than structural capacitors in the literature.

Designing single- and multiple-shell sampling schemes for diffusion MRI using spherical code.

PubMed

Cheng, Jian; Shen, Dinggang; Yap, Pew-Thian

2014-01-01

In diffusion MRI (dMRI), determining an appropriate sampling scheme is crucial for acquiring the maximal amount of information for data reconstruction and analysis using the minimal amount of time. For single-shell acquisition, uniform sampling without directional preference is usually favored. To achieve this, a commonly used approach is the Electrostatic Energy Minimization (EEM) method introduced in dMRI by Jones et al. However, the electrostatic energy formulation in EEM is not directly related to the goal of optimal sampling-scheme design, i.e., achieving large angular separation between sampling points. A mathematically more natural approach is to consider the Spherical Code (SC) formulation, which aims to achieve uniform sampling by maximizing the minimal angular difference between sampling points on the unit sphere. Although SC is well studied in the mathematical literature, its current formulation is limited to a single shell and is not applicable to multiple shells. Moreover, SC, or more precisely continuous SC (CSC), currently can only be applied on the continuous unit sphere and hence cannot be used in situations where one or several subsets of sampling points need to be determined from an existing sampling scheme. In this case, discrete SC (DSC) is required. In this paper, we propose novel DSC and CSC methods for designing uniform single-/multi-shell sampling schemes. The DSC and CSC formulations are solved respectively by Mixed Integer Linear Programming (MILP) and a gradient descent approach. A fast greedy incremental solution is also provided for both DSC and CSC. To our knowledge, this is the first work to use SC formulation for designing sampling schemes in dMRI. Experimental results indicate that our methods obtain larger angular separation and better rotational invariance than the generalized EEM (gEEM) method currently used in the Human Connectome Project (HCP).

MIA - A free and open source software for gray scale medical image analysis

PubMed Central

2013-01-01

Background Gray scale images make the bulk of data in bio-medical image analysis, and hence, the main focus of many image processing tasks lies in the processing of these monochrome images. With ever improving acquisition devices, spatial and temporal image resolution increases, and data sets become very large. Various image processing frameworks exists that make the development of new algorithms easy by using high level programming languages or visual programming. These frameworks are also accessable to researchers that have no background or little in software development because they take care of otherwise complex tasks. Specifically, the management of working memory is taken care of automatically, usually at the price of requiring more it. As a result, processing large data sets with these tools becomes increasingly difficult on work station class computers. One alternative to using these high level processing tools is the development of new algorithms in a languages like C++, that gives the developer full control over how memory is handled, but the resulting workflow for the prototyping of new algorithms is rather time intensive, and also not appropriate for a researcher with little or no knowledge in software development. Another alternative is in using command line tools that run image processing tasks, use the hard disk to store intermediate results, and provide automation by using shell scripts. Although not as convenient as, e.g. visual programming, this approach is still accessable to researchers without a background in computer science. However, only few tools exist that provide this kind of processing interface, they are usually quite task specific, and don’t provide an clear approach when one wants to shape a new command line tool from a prototype shell script. Results The proposed framework, MIA, provides a combination of command line tools, plug-ins, and libraries that make it possible to run image processing tasks interactively in a command shell and to prototype by using the according shell scripting language. Since the hard disk becomes the temporal storage memory management is usually a non-issue in the prototyping phase. By using string-based descriptions for filters, optimizers, and the likes, the transition from shell scripts to full fledged programs implemented in C++ is also made easy. In addition, its design based on atomic plug-ins and single tasks command line tools makes it easy to extend MIA, usually without the requirement to touch or recompile existing code. Conclusion In this article, we describe the general design of MIA, a general purpouse framework for gray scale image processing. We demonstrated the applicability of the software with example applications from three different research scenarios, namely motion compensation in myocardial perfusion imaging, the processing of high resolution image data that arises in virtual anthropology, and retrospective analysis of treatment outcome in orthognathic surgery. With MIA prototyping algorithms by using shell scripts that combine small, single-task command line tools is a viable alternative to the use of high level languages, an approach that is especially useful when large data sets need to be processed. PMID:24119305

MIA - A free and open source software for gray scale medical image analysis.

PubMed

Wollny, Gert; Kellman, Peter; Ledesma-Carbayo, María-Jesus; Skinner, Matthew M; Hublin, Jean-Jaques; Hierl, Thomas

2013-10-11

Gray scale images make the bulk of data in bio-medical image analysis, and hence, the main focus of many image processing tasks lies in the processing of these monochrome images. With ever improving acquisition devices, spatial and temporal image resolution increases, and data sets become very large.Various image processing frameworks exists that make the development of new algorithms easy by using high level programming languages or visual programming. These frameworks are also accessable to researchers that have no background or little in software development because they take care of otherwise complex tasks. Specifically, the management of working memory is taken care of automatically, usually at the price of requiring more it. As a result, processing large data sets with these tools becomes increasingly difficult on work station class computers.One alternative to using these high level processing tools is the development of new algorithms in a languages like C++, that gives the developer full control over how memory is handled, but the resulting workflow for the prototyping of new algorithms is rather time intensive, and also not appropriate for a researcher with little or no knowledge in software development.Another alternative is in using command line tools that run image processing tasks, use the hard disk to store intermediate results, and provide automation by using shell scripts. Although not as convenient as, e.g. visual programming, this approach is still accessable to researchers without a background in computer science. However, only few tools exist that provide this kind of processing interface, they are usually quite task specific, and don't provide an clear approach when one wants to shape a new command line tool from a prototype shell script. The proposed framework, MIA, provides a combination of command line tools, plug-ins, and libraries that make it possible to run image processing tasks interactively in a command shell and to prototype by using the according shell scripting language. Since the hard disk becomes the temporal storage memory management is usually a non-issue in the prototyping phase. By using string-based descriptions for filters, optimizers, and the likes, the transition from shell scripts to full fledged programs implemented in C++ is also made easy. In addition, its design based on atomic plug-ins and single tasks command line tools makes it easy to extend MIA, usually without the requirement to touch or recompile existing code. In this article, we describe the general design of MIA, a general purpouse framework for gray scale image processing. We demonstrated the applicability of the software with example applications from three different research scenarios, namely motion compensation in myocardial perfusion imaging, the processing of high resolution image data that arises in virtual anthropology, and retrospective analysis of treatment outcome in orthognathic surgery. With MIA prototyping algorithms by using shell scripts that combine small, single-task command line tools is a viable alternative to the use of high level languages, an approach that is especially useful when large data sets need to be processed.

Numerical nonlinear inelastic analysis of stiffened shells of revolution. Volume 3: Engineer's program manual for STARS-2P digital computer program

NASA Technical Reports Server (NTRS)

Svalbonas, V.; Levine, H.; Ogilvie, P.

1975-01-01

Engineering programming information is presented for the STARS-2P (shell theory automated for rotational structures-2P (plasticity)) digital computer program, and FORTRAN 4 was used in writing the various subroutines. The execution of this program requires the use of thirteen temporary storage units. The program was initially written and debugged on the IBM 370-165 computer and converted to the UNIVAC 1108 computer, where it utilizes approximately 60,000 words of core. Only basic FORTRAN library routines are required by the program: sine, cosine, absolute value, and square root.

Holographic shell model: Stack data structure inside black holes?

NASA Astrophysics Data System (ADS)

Davidson, Aharon

2014-03-01

Rather than tiling the black hole horizon by Planck area patches, we suggest that bits of information inhabit, universally and holographically, the entire black core interior, a bit per a light sheet unit interval of order Planck area difference. The number of distinguishable (tagged by a binary code) configurations, counted within the context of a discrete holographic shell model, is given by the Catalan series. The area entropy formula is recovered, including Cardy's universal logarithmic correction, and the equipartition of mass per degree of freedom is proven. The black hole information storage resembles, in the count procedure, the so-called stack data structure.

Stable Radical Materials for Energy Applications.

PubMed

Wilcox, Daniel A; Agarkar, Varad; Mukherjee, Sanjoy; Boudouris, Bryan W

2018-06-07

Although less studied than their closed-shell counterparts, materials containing stable open-shell chemistries have played a key role in many energy storage and energy conversion devices. In particular, the oxidation-reduction (redox) properties of these stable radicals have made them a substantial contributor to the progress of organic batteries. Moreover, the use of radical-based materials in photovoltaic devices and thermoelectric systems has allowed for these emerging molecules to have impacts in the energy conversion realm. Additionally, the unique doublet states of radical-based materials provide access to otherwise inaccessible spin states in optoelectronic devices, offering many new opportunities for efficient usage of energy in light-emitting devices. Here, we review the current state of the art regarding the molecular design, synthesis, and application of stable radicals in these energy-related applications. Finally, we point to fundamental and applied arenas of future promise for these designer open-shell molecules, which have only just begun to be evaluated in full.

Transient Response of Shells of Revolution by Direct Integration and Modal Superposition Methods

NASA Technical Reports Server (NTRS)

Stephens, W. B.; Adelman, H. M.

1974-01-01

The results of an analytical effort to obtain and evaluate transient response data for a cylindrical and a conical shell by use of two different approaches: direct integration and modal superposition are described. The inclusion of nonlinear terms is more important than the inclusion of secondary linear effects (transverse shear deformation and rotary inertia) although there are thin-shell structures where these secondary effects are important. The advantages of the direct integration approach are that geometric nonlinear and secondary effects are easy to include and high-frequency response may be calculated. In comparison to the modal superposition technique the computer storage requirements are smaller. The advantages of the modal superposition approach are that the solution is independent of the previous time history and that once the modal data are obtained, the response for repeated cases may be efficiently computed. Also, any admissible set of initial conditions can be applied.

A universal cooperative assembly-directed method for coating of mesoporous TiO2 nanoshells with enhanced lithium storage properties

PubMed Central

Guan, Bu Yuan; Yu, Le; Li, Ju; Lou, Xiong Wen (David)

2016-01-01

TiO2 is exceptionally useful, but it remains a great challenge to develop a universal method to coat TiO2 nanoshells on different functional materials. We report a one-pot, low-temperature, and facile method that can rapidly form mesoporous TiO2 shells on various inorganic, organic, and inorganic-organic composite materials, including silica-based, metal, metal oxide, organic polymer, carbon-based, and metal-organic framework nanomaterials via a cooperative assembly-directed strategy. In constructing hollow, core-shell, and yolk-shell geometries, both amorphous and crystalline TiO2 nanoshells are demonstrated with excellent control. When used as electrode materials for lithium ion batteries, these crystalline TiO2 nanoshells composed of very small nanocrystals exhibit remarkably long-term cycling stability over 1000 cycles. The electrochemical properties demonstrate that these TiO2 nanoshells are promising anode materials. PMID:26973879

Hybrid carbon nanoparticles modified core-shell silica: a high efficiency carbon-based phase for hydrophilic interaction liquid chromatography.

PubMed

Ibrahim, Mohammed E A; Wahab, M Farooq; Lucy, Charles A

2014-04-11

Hydrophilic interaction liquid chromatography (HILIC) is a fast growing separation technique for hydrophilic and polar analytes. In this work, we combine the unique selectivity of carbon surfaces with the high efficiency of core-shell silica. First, 5 μm core-shell silica is electrostatically coated with 105 nm cationic latex bearing quaternary ammonium groups. Then 50 nm anionic carbon nanoparticles are anchored onto the surface of the latex coated core-shell silica particles to produce a hybrid carbon-silica phase. The hybrid phase shows different selectivity than ten previously classified HILIC column chemistries and 36 stationary phases. The hybrid HILIC phase has shape selectivity for positional isomeric pairs (phthalic/isophthalic and 1-naphthoic/2-naphthoic acids). Fast and high efficiency HILIC separations of biologically important carboxylates, phenols and pharmaceuticals are reported with efficiencies up to 85,000 plates m(-1). Reduced plate height of 1.9 (95,000 plates m(-1)) can be achieved. The hybrid phase is stable for at least 3 months of usage and storage under typical HILIC eluents. Copyright © 2014 Elsevier B.V. All rights reserved.

Folic acid-functionalized magnetic ZnFe2O4 hollow microsphere core/mesoporous silica shell composite particles: synthesis and application in drug release.

PubMed

Yang, Dandan; Wei, Kaiwei; Liu, Qi; Yang, Yong; Guo, Xue; Rong, Hongren; Cheng, Mei-Ling; Wang, Guoxiu

2013-07-01

A drug delivery system was designed by deliberately combining the useful functions into one entity, which was composed of magnetic ZnFe2O4 hollow microsphere as the core, and mesoporous silica with folic acid molecules as the outer shell. Amine groups coated magnetic ZnFe2O4 hollow microsphere core/mesoporous silica shell (MZHM-MSS-NH2) composite particles were first synthesized by a one-pot direct co-condensation method. Subsequently a novel kind of folic acid-functionalized magnetic ZnFe2O4 hollow microsphere core/mesoporous silica shell (MZHM-MSS-NHFA) composite particles were synthesized by conjugating folic acid as targeted molecule to MZHM-MSS-NH2. Ibuprofen, a well-known antiphlogistic drug, was used as a model drug to assess the loading and releasing behavior of the composite microspheres. The results show that the MZHM-MSS-NHFA system has the higher capacity of drug storage and good sustained drug-release property. Copyright © 2013 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ford, A.L.; Reading, J.F.; Becker, R.L.

Theoretical methods used previously for H/sup +/, He/sup 2 +/, and C/sup 6 +/ collisions with neutral argon atoms have been applied to collisions of H/sup +/, He/sup 2 +/, and Li/sup 3 +/ projectiles with neon, and to collisions of H/sup +/ with carbon targets. The energy range covered by the calculations is 0.4 to 4.0 MeV/amu for the neon target, and 0.2 to 2.0 MeV/amu for carbon. We calculate single-electron amplitudes for target K-shell ionization and target K- and L-shell, to projectile K-shell, charge transfer. These single-electron amplitudes are used, in an independent-particle model that allows for multielectronmore » processes, to compute K-shell vacancy production cross sections sigma/sup IPM//sub V/K, and cross sections sigma/sup IPM//sub C/,VK for producing a charge-transfer state of the projectile in the coincidence with a K-shell vacancy in the target. These cross sections are in reasonable agreement with the recent experiments of Rodbro et al. at Aarhus. In particular, the calculated, as well as the experimental, sigma/sub C/,VK scale with projectile nuclear charge Z/sub p/ less strongly than the Z/sup 5//sub p/ of the Oppenheimer-Brinkman-Kramers (OBK) approximation. For He/sup 2 +/ and Li/sup 3 +/ projectiles at collision energies below where experimental data are available, our calculated multielectron corrections to the single-electron approximation for sigma/sub C/,VK are large.« less

Glass shell manufacturing in space

NASA Technical Reports Server (NTRS)

Downs, R. L.; Ebner, M. A.; Nolen, R. L., Jr.

1981-01-01

Highly-uniform, hollow glass spheres (shells), which are used for inertial confinement fusion targets, were formed from metal-organic gel powder feedstock in a vertical furnace. As a result of the rapid pyrolysis caused by the furnace, the gel is transformed to a shell in five distinct stages: (a) surface closure of the porous gel; (b) generation of a closed-cell foam structure in the gel; (c) spheridization of the gel and further expansion of the foam; (d) coalescence of the closed-cell foam to a single-void shell; and (e) fining of the glass shell. The heat transfer from the furnace to the falling gel particle was modeled to determine the effective heating rate of the gel. The model predicts the temperature history for a particle as a function of mass, dimensions, specific heat, and absorptance as well as furnace temperature profile and thermal conductivity of the furnace gas. A model was developed that predicts the gravity-induced degradation of shell concentricity in falling molten shells as a function of shell characteristics and time.

PMMA/PS coaxial electrospinning: core-shell fiber morphology as a function of material parameters

NASA Astrophysics Data System (ADS)

Rahmani, Shahrzad; Arefazar, Ahmad; Latifi, Masoud

2017-03-01

Core-shell fibers of polymethyl methacrylate (PMMA) and polystyrene (PS) have been successfully electrospun by coaxial electrospinning. To evaluate the influence of the solvent on the final fiber morphology, four types of organic solvents were used in the shell solution while the core solvent was preserved. Morphological observations with scanning electron microscopy, transmission electron microscopy and optical microscopy revealed that both core and shell solvent properties were involved in the final fiber morphology. To explain this involvement, alongside a discussion of the Bagley solubility graph of PS and PMMA, a novel criterion based on solvent physical properties was introduced. A theoretical model based on the momentum conservation principle was developed and applied for describing the dependence of the core and shell diameters to their solvent combinations. Different concentrations of core and shell were also investigated in the coaxial electrospinning of PMMA/PS. The core-shell fiber morphologies with different core and shell concentrations were compared with their single electrospun fibers.

Visualization of Bacterial Microcompartment Facet Assembly Using High-Speed Atomic Force Microscopy

DOE PAGES

Sutter, Markus; Faulkner, Matthew; Aussignargues, Clément; ...

2015-11-30

Bacterial microcompartments (BMCs) are proteinaceous organelles widespread among bacterial phyla. They compartmentalize enzymes within a selectively permeable shell and play important roles in CO 2 fixation, pathogenesis, and microbial ecology. Here, we combine X-ray crystallography and high-speed atomic force microscopy to characterize, at molecular resolution, the structure and dynamics of BMC shell facet assembly. Our results show that preformed hexamers assemble into uniformly oriented shell layers, a single hexamer thick. We also observe the dynamic process of shell facet assembly. Shell hexamers can dissociate from and incorporate into assembled sheets, indicating a flexible intermolecular interaction. Furthermore, we demonstrate that themore » self-assembly and dynamics of shell proteins are governed by specific contacts at the interfaces of shell proteins. Our study provides novel insights into the formation, interactions, and dynamics of BMC shell facets, which are essential for the design and engineering of self-assembled biological nanoreactors and scaffolds based on BMC architectures.« less

Solar-Light-Driven Renewable Butanol Separation by Core-Shell Ag@ZIF-8 Nanowires.

PubMed

Liu, Xu; He, Liangcan; Zheng, Jianzhong; Guo, Jun; Bi, Feng; Ma, Xiang; Zhao, Kun; Liu, Yaling; Song, Rui; Tang, Zhiyong

2015-06-03

Core-shell Ag@ZIF-8 nanowires, where single Ag nanowires are coated with uniform zeolitic-imidazolate-framework-8 (ZIF-8) shells, successfully realize renewable adsorptive separation of low concentrations of butanol from an aqueous medium under solar light irradiation by taking advantage of the exceptional adsorption capability of the ZIF-8 shells toward butanol and the unique plasmonic photothermal effect of the Ag nanowire cores. Impressively, the high separation efficiency is maintained as almost unchanged, even after 10 adsorption/desorption cycles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Review of high convergence implosion experiments with single and double shell targets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Delamater, N. D.; Watt, R. G.; Varnum, W. S.

2002-01-01

Experiments have been been performed in recent years at the Omega laser studying double shell capsules as an a1 teinative, 11011 cryogenic, path towards ignition at NTF. Double shell capsules designed to mitigate the Au M-band radiation asymmetries, were experimentally found to perform well in both spherical and cylindrical hohlraums, achieving near 1-D (-90 %) clean calculated yield at convergence comparable to that required for NIF ignition. Near-term plans include directly driven double shell experiments at Omega, which eliminates Au M-band radiation as a yield degradation m ec h an i s in.

Real-Time Intracellular Measurements of ROS and RNS in Living Cells with Single Core-Shell Nanowire Electrodes.

PubMed

Zhang, Xin-Wei; Qiu, Quan-Fa; Jiang, Hong; Zhang, Fu-Li; Liu, Yan-Lin; Amatore, Christian; Huang, Wei-Hua

2017-10-09

Nanoelectrodes allow precise and quantitative measurements of important biological processes at the single living-cell level in real time. Cylindrical nanowire electrodes (NWEs) required for intracellular measurements create a great challenge for achieving excellent electrochemical and mechanical performances. Herein, we present a facile and robust solution to this problem based on a unique SiC-core-shell design to produce cylindrical NWEs with superior mechanical toughness provided by the SiC nano-core and an excellent electrochemical performance provided by the ultrathin carbon shell that can be used as such or platinized. The use of such NWEs for biological applications is illustrated by the first quantitative measurements of ROS/RNS in individual phagolysosomes of living macrophages. As the shell material can be varied to meet any specific detection purpose, this work opens up new opportunities to monitor quantitatively biological functions occurring inside cells and their organelles. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An efficient finite element with layerwise mechanics for smart piezoelectric composite and sandwich shallow shells

NASA Astrophysics Data System (ADS)

Yasin, M. Yaqoob; Kapuria, S.

2014-01-01

In this work, we present a new efficient four-node finite element for shallow multilayered piezoelectric shells, considering layerwise mechanics and electromechanical coupling. The laminate mechanics is based on the zigzag theory that has only seven kinematic degrees of freedom per node. The normal deformation of the piezoelectric layers under the electric field is accounted for without introducing any additional deflection variables. A consistent quadratic variation of the electric potential across the piezoelectric layers with the provision of satisfying the equipotential condition of electroded surfaces is adopted. The performance of the new element is demonstrated for the static response under mechanical and electric potential loads, and for free vibration response of smart shells under different boundary conditions. The predictions are found to be very close to the three dimensional piezoelasticity solutions for hybrid shells made of not only single-material composite substrates, but also sandwich substrates with a soft core for which the equivalent single layer (ESL) theories perform very badly.

Cr2O3 ultrasmall nanoparticles filled carbon nanocapsules deriving from Cr(VI) for enhanced lithium storage

NASA Astrophysics Data System (ADS)

Zhao, Yun; Wang, Jianjiao; Ma, Canliang; Li, Yong

2018-07-01

Based on the considerations in environmental and economic benefits, Cr2O72- as the major chromium pollutant is employed for applications in energy storage. A novel Cr2O3 ultrasmall nanoparticles (NPs) (<5 nm) filled carbon nanocapsule configuration is achieved through a surfactant-free solvothermal route with renewable furfural as the carbon source. The confinement effect that Cr2O3 NPs are restrained in the outer robust carbon shell and the plenty space among Cr2O3 NPs result in substantially enhanced Li-storage performances, such as stable capacity of 568 mAh g-1 at 100 mA g-1 after more than 200 cycles and high capacity retention at large current density.

Implosion Dynamics and Mix in Double-Shell ICF Capsule Designs

NASA Astrophysics Data System (ADS)

Gunderson, Mark; Daughton, William; Simakov, Andrei; Wilson, Douglas; Watt, Robert; Delamater, Norman; Montgomery, David

2015-11-01

From an implosion dynamics perspective, double-shell ICF capsule designs have several advantages over the single-shell NIF ICF capsule point design. Double shell designs do not require precise shock sequencing, do not rely on hot spot ignition, have lower peak implosion speed requirements, and have lower convergence ratio requirements. However, there are still hurdles that must be overcome. The timing of the two main shocks in these designs is important in achieving sufficient compression of the DT fuel. Instability of the inner gold shell due to preheat from the hohlraum environment can disrupt the implosion of the inner pill. Mix, in addition to quenching burn in the DT fuel, also decreases the transfer of energy between the beryllium ablator and the inner gold shell during collision thus decreasing the implosion speed of the inner shell along with compression of the DT fuel. Herein, we will discuss practical implications of these effects on double-shell design we carry out in preparation for the NIF double-shell campaign. Work performed under the auspices of DOE by LANL under contract DE-AC52-06NA25396.

Design and Synthesis of Spherical Multicomponent Aggregates Composed of Core-Shell, Yolk-Shell, and Hollow Nanospheres and Their Lithium-Ion Storage Performances.

PubMed

Park, Gi Dae; Kang, Yun Chan

2018-03-01

Micrometer-sized spherical aggregates of Sn and Co components containing core-shell, yolk-shell, hollow nanospheres are synthesized by applying nanoscale Kirkendall diffusion in the large-scale spray drying process. The Sn 2 Co 3 -Co 3 SnC 0.7 -C composite microspheres uniformly dispersed with Sn 2 Co 3 -Co 3 SnC 0.7 mixed nanocrystals are formed by the first-step reduction of spray-dried precursor powders at 900 °C. The second-step oxidation process transforms the Sn 2 Co 3 -Co 3 SnC 0.7 -C composite into the porous microsphere composed of Sn-Sn 2 Co 3 @CoSnO 3 -Co 3 O 4 core-shell, Sn-Sn 2 Co 3 @CoSnO 3 -Co 3 O 4 yolk-shell, and CoSnO 3 -Co 3 O 4 hollow nanospheres at 300, 400, and 500 °C, respectively. The discharge capacity of the microspheres with Sn-Sn 2 Co 3 @CoSnO 3 -Co 3 O 4 core-shell, Sn-Sn 2 Co 3 @CoSnO 3 -Co 3 O 4 yolk-shell, and CoSnO 3 -Co 3 O 4 hollow nanospheres for the 200 th cycle at a current density of 1 A g -1 is 1265, 987, and 569 mA h g -1 , respectively. The ultrafine primary nanoparticles with a core-shell structure improve the structural stability of the porous-structured microspheres during repeated lithium insertion and desertion processes. The porous Sn-Sn 2 Co 3 @CoSnO 3 -Co 3 O 4 microspheres with core-shell primary nanoparticles show excellent cycling and rate performances as anode materials for lithium-ion batteries. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bipolar resistive switching of single gold-in-Ga2O3 nanowire.

PubMed

Hsu, Chia-Wei; Chou, Li-Jen

2012-08-08

We have fabricated single nanowire chips on gold-in-Ga(2)O(3) core-shell nanowires using the electron-beam lithography techniques and realized bipolar resistive switching characteristics having invariable set and reset voltages. We attribute the unique property of invariance to the built-in conduction path of gold core. This invariance allows us to fabricate many resistive switching cells with the same operating voltage by simple depositing repetitive metal electrodes along a single nanowire. Other characteristics of these core-shell resistive switching nanowires include comparable driving electric field with other thin film and nanowire devices and a remarkable on/off ratio more than 3 orders of magnitude at a low driving voltage of 2 V. A smaller but still impressive on/off ratio of 10 can be obtained at an even lower bias of 0.2 V. These characteristics of gold-in-Ga(2)O(3) core-shell nanowires make fabrication of future high-density resistive memory devices possible.

Single Domain SmCo5@Co Exchange-coupled Magnets Prepared from Core/shell Sm[Co(CN)6]·4H2O@GO Particles: A Novel Chemical Approach

PubMed Central

Yang, Ce; Jia, Lihui; Wang, Shouguo; Gao, Chen; Shi, Dawei; Hou, Yanglong; Gao, Song

2013-01-01

SmCo5 based magnets with smaller size and larger maximum energy product have been long desired in various fields such as renewable energy technology, electronic industry and aerospace science. However, conventional relatively rough synthetic strategies will lead to either diminished magnetic properties or irregular morphology, which hindered their wide applications. In this article, we present a facile chemical approach to prepare 200 nm single domain SmCo5@Co core/shell magnets with coercivity of 20.7 kOe and saturation magnetization of 82 emu/g. We found that the incorporation of GO sheets is responsible for the generation of the unique structure. The single domain SmCo5 core contributes to the large coercivity of the magnets and the exchange-coupled Co shell enhances the magnetization. This method can be further utilized in the synthesis other Sm-Co based exchange-coupled magnets. PMID:24356309

Inside-out Core–shell Architecture: Controllable Fabrication of Cu2O@Cu with High Activity for the Sonogashira Coupling Reaction

EPA Science Inventory

As low-cost and versatile materials, Cu and its oxides have attracted great interest due to their excellent performance in the field of catalysis, superconductivity, photovoltaics, magnetic storage, electrochemistry, and biosensing. It is well known that morphology has an import...

Pesticide residues in birds and mammals

USGS Publications Warehouse

Stickel, L.F.; Edwards, C.A.

1973-01-01

SUMMARY: Residues of organochlorine pesticides and their breakdown products are present in the tissues of essentially all wild birds throughout the world. These chemicals accumulate in fat from a relatively small environmental exposure. DDE and dieldrin are most prevalent. Others, such as heptachlor epoxide, chlordane, endrin, and benzene hexachloride also occur, the quantities and kinds generally reflecting local or regional use. Accumulation may be sufficient to kill animals following applications for pest control. This has occurred in several large-scale programmes in the United States. Mortality has also resulted from unintentional leakage of chemical from commercial establishments. Residues may persist in the environment for many years, exposing successive generations of animals. In general, birds that eat other birds, or fish, have higher residues than those that eat seeds and vegetation. The kinetic processes of absorption, metabolism, storage, and output differ according to both kind of chemical and species of animal. When exposure is low and continuous, a balance between intake and excretion may be achieved. Residues reach a balance at an approximate animal body equilibrium or plateau; the storage is generally proportional to dose. Experiments with chickens show that dieldrin and heptachlor epoxide have the greatest propensity for storage, endrin next, then DDT, then lindane. The storage of DDT was complicated by its metabolism to DDE and DDD, but other studies show that DDE has a much greater propensity for storage than either DDD or DDT. Methoxychlor has little cumulative capacity in birds. Residues in eggs reflect and parallel those in the parent bird during accumulation, equilibrium, and decline when dosage is discontinued. Residues with the greatest propensity for storage are also lost most slowly. Rate of loss of residues can be modified by dietary components and is speeded by weight loss of the animal. Under sublethal conditions of continuous exposure to an organochlorine pesticide, the concentrations of residues in the different tissues are ordinarily directly correlated with each other. When the dosage is at lethal levels, or when stored residues are mobilised to lethal levels, the balanced relationship is disrupted. The concentrations of residues in the brain provide the most rigorous criteria for diagnosis of death due to these chemicals, and levels are generally similar across a wide range of species of birds and mammals. Residues in liver are closely correlated with recent dose, either from direct intake or from mobilisation from storage, and so reflect hazardous exposure. Residues in the whole carcass show the storage reserve, and so indicate the potential for adverse effects from lethal mobilisation or from the continuous slow mobilisation that occurs during the normal processes of metabolism and excretion. A synchronous, rapid, and widespread decline in weight and thickness of shells of eggs laid by many species of wild birds occurred in the late 1940's and has persisted. Birds of prey were primarily affected; exceptions apparently are the result of lesser exposure because of different food habits. Many species of fish-eating birds are also affected. Others, however, appear to be more resistant and to accumulate much higher residues before shell-thinning occurs. Seed-eating birds do not appear to have been generally affected; their exposure is ordinarily lower, but physiological factors also seem to be involved. A relationship between shell-thinning and population decline has been established for many species. In exceptional cases, such as the herring gull, persistent re-nesting and other population reactions have overcome adverse effects at the population level. The discovery of shell-thinning among natural populations, and the hypothesis that this thinning was related to the occurrence of organochlorine pesticides, stimulated experimental studies to determine wheth

Analysis and test results for a molten salt thermal energy storage system

NASA Astrophysics Data System (ADS)

Sterrett, R. H.; Scott, O. L.

A system has been developed to provide low cost thermal energy storage using molten salt. It consists of a hot tank to store the 565 C (1050 F) salt and a cold tank to store the 289 C (550 F) salt. The hot tank uses internal insulation protected by a liner to enable the use of a carbon steel shell for structural support. Due to the lower salt temperature, the cold tank can be a carbon steel shell with external insulation. This paper describes an analytical method used to predict the thermal performance of such systems and presents experimental data from a Subsystem Research Experiment (SRE) conducted by Martin Marietta Aerospace, Solar Energy Systems under contract from Sandia National Laboratories, Livermore, CA. The results from three of the SRE test cases are compared with the STS model results. These are (1) steady state operation, (2) concurrent charging and discharging, and (3) transient cooldown. The temperature differences between the analytical and experimental results were less than 10%. The internally insulated hot tank performed well.

Active heat exchange system development for latent heat thermal energy storage

NASA Technical Reports Server (NTRS)

Alario, J.; Kosson, R.; Haslett, R.

1980-01-01

Various active heat exchange concepts were identified from among three generic categories: scrapers, agitators/vibrators and slurries. The more practical ones were given a more detailed technical evaluation and an economic comparison with a passive tube-shell design for a reference application (300 MW sub t storage for 6 hours). Two concepts were selected for hardware development: (1) a direct contact heat exchanger in which molten salt droplets are injected into a cooler counterflowing stream of liquid metal carrier fluid, and (2) a rotating drum scraper in which molten salt is sprayed onto the circumference of a rotating drum, which contains the fluid salt is sprayed onto the circumference of a rotating drum, which contains the fluid heat sink in an internal annulus near the surface. A fixed scraper blade removes the solidified salt from the surface which was nickel plated to decrease adhesion forces. In addition to improving performance by providing a nearly constant transfer rate during discharge, these active heat exchanger concepts were estimated to cost at least 25% less than the passive tube-shell design.

A study of fluid-structure problems

NASA Astrophysics Data System (ADS)

Lam, Dennis Kang-Por

The stability of structures with and without fluid load is investigated. A method is developed for determining the fluid load in terms of added structural mass. Finite element methods are employed to study the buckling of a cylindrical shell under axial compression and liquid storage tanks under hydrodynamic load. Both linear and nonlinear analyses are performed. Diamond modes are found to be the possible postbuckling shapes of the cylindrical shell. Local buckling including elephant-foot buckle and diamond buckle are found for the liquid storage tank models. Comparison between the linear and nonlinear results indicates a substantial difference in buckling mode shapes, though the buckling loads are close to each other. The method for determining the hydrodynamic mass is applied to the impeller stage of a centrifugal pump. The method is based on a linear perturbation technique which assumes that the disturbance in the flow boundaries and velocities caused by the motion of the structure is small. A potential method is used to estimate the velocity flow field. The hydrodynamic mass is then obtained by calculating the total force which results from the pressure induced by a perturbation of the structure.

Microstructure and Thermal Reliability of Microcapsules Containing Phase Change Material with Self-Assembled Graphene/Organic Nano-Hybrid Shells.

PubMed

Wang, Xianfeng; Guo, Yandong; Su, Junfeng; Zhang, Xiaolong; Han, Ningxu; Wang, Xinyu

2018-05-24

In recent decades, microcapsules containing phase change materials (microPCMs) have been the center of much attention in the field of latent thermal energy storage. The aim of this work was to prepare and investigate the microstructure and thermal conductivity of microPCMs containing self-assembled graphene/organic hybrid shells. Paraffin was used as a phase change material, which was successfully microencapsulated by graphene and polymer forming hybrid composite shells. The physicochemical characters of microPCM samples were investigated including mean size, shell thickness, and chemical structure. Scanning electron microscope (SEM) results showed that the microPCMs were spherical particles and graphene enhanced the degree of smoothness of the shell surface. The existence of graphene in the shells was proved by using the methods of X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and atomic force microscopy (AFM). It was found that graphene hybrid shells were constructed by forces of electric charge absorption and long-molecular entanglement. MicroPCMs with graphene had a higher degradation temperature of 300 °C. Graphene greatly enhanced the thermal stability of microPCMs. The thermal conductivity tests indicated that the phase change temperature of microPCMs was regulated by the graphene additive because of enhancement of the thermal barrier of the hybrid shells. Differential scanning calorimetry (DSC) tests proved that the latent thermal energy capability of microPCMs had been improved with a higher heat conduction rate. In addition, infrared thermograph observations implied that the microPCMs had a sensitivity response to heat during the phase change cycling process because of the excellent thermal conductivity of graphene.

Highly stable multi-wall carbon nanotubes@poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) core-shell composites with three-dimensional porous nano-network for electrochemical capacitors

NASA Astrophysics Data System (ADS)

Zhou, Haihan; Han, Gaoyi; Chang, Yunzhen; Fu, Dongying; Xiao, Yaoming

2015-01-01

A facile and feasible electrochemical polymerization method has been used to construct the multi-wall carbon nanotubes@poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (MWCNTs@PEDOT/PSS) core-shell composites with three-dimensional (3D) porous nano-network microstructure. The composites are characterized with Fourier transform infrared spectroscopy, scanning electron microscope, and transmission electron microscopy. This special core-shell nanostructure can significantly reduce the ions diffusion distance and the 3D porous nano-network microstructure effectively enlarges the electrode/electrolyte interface. The electrochemical tests including cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy tests are performed, the results manifest the MWCNTs@PEDOT/PSS core-shell composites have superior capacitive behaviors and excellent cyclic stability, and a high areal capacitance of 98.1 mF cm-2 is achieved at 5 mV s-1 cyclic voltammetry scan. Furthermore, the MWCNTs@PEDOT/PSS composites exhibit obviously superior capacitive performance than that of PEDOT/PSS and PEDOT/Cl electrodes, indicating the effective composite of MWCNTs and PEDOT noticeably boosts the capacitive performance of PEDOT-based electrodes for electrochemical energy storage. Such a highly stable core-shell 3D network structural composite is very promising to be used as electrode materials for the high-performance electrochemical capacitors.

Dependence of weak interaction rates on the nuclear composition during stellar core collapse

NASA Astrophysics Data System (ADS)

Furusawa, Shun; Nagakura, Hiroki; Sumiyoshi, Kohsuke; Kato, Chinami; Yamada, Shoichi

2017-02-01

We investigate the influences of the nuclear composition on the weak interaction rates of heavy nuclei during the core collapse of massive stars. The nuclear abundances in nuclear statistical equilibrium (NSE) are calculated by some equation of state (EOS) models including in-medium effects on nuclear masses. We systematically examine the sensitivities of electron capture and neutrino-nucleus scattering on heavy nuclei to the nuclear shell effects and the single-nucleus approximation. We find that the washout of the shell effect at high temperatures brings significant change to weak rates by smoothing the nuclear abundance distribution: the electron capture rate decreases by ˜20 % in the early phase and increases by ˜40 % in the late phase at most, while the cross section for neutrino-nucleus scattering is reduced by ˜15 % . This is because the open-shell nuclei become abundant instead of those with closed neutron shells as the shell effects disappear. We also find that the single-nucleus description based on the average values leads to underestimations of weak rates. Electron captures and neutrino coherent scattering on heavy nuclei are reduced by ˜80 % in the early phase and by ˜5 % in the late phase, respectively. These results indicate that NSE like EOS accounting for shell washout is indispensable for the reliable estimation of weak interaction rates in simulations of core-collapse supernovae.

Rational Design of Hierarchical Nanotubes through Encapsulating CoSe2 Nanoparticles into MoSe2/C Composite Shells with Enhanced Lithium and Sodium Storage Performance.

PubMed

Gao, Jingyu; Li, Yapeng; Shi, Liang; Li, Jingjing; Zhang, Genqiang

2018-06-20

Transition-metal diselenides have been extensively studied as desirable anode candidates for both lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) because of their high theoretical capacities. However, it is of great challenge to achieve satisfactory cycling performance, especially for larger sodium ion storage, originated from electrode deterioration upon large volume change. Herein, we reported the construction of hierarchical tubular hybrid nanostructures through encapsulating CoSe 2 nanoparticles into MoSe 2 /C composite shells via a simple two-step strategy including a hydrothermal method followed by vapor-phase selenization process. The unique tubular structure enables the highly reversible Li/Na storage with high specific capacity, enhanced cycling stability, and superior rate performance. It is indicated that the contribution of partial pseudocapacitive behavior greatly improves the rate capability for SIBs, where a high capacity retention of 81.5% can be obtained when the current densities range from 0.1 to 3 A g -1 (460 mA h g -1 at 0.1 A g -1 vs 379 mA h g -1 at 3 A g -1 ). This work provides an effective design rationale on transition-metal diselenide-based tubular nanostructures as superior hosts for both Li and Na ions, which could push forward the development of practical applications of transition-metal diselenide-based anodes in LIBs and SIBs.

The Quest CCS Project - MMV Technology Deployment Through Two Years of Operation

NASA Astrophysics Data System (ADS)

O'Brien, S.

2017-12-01

In September 2012, Shell, on behalf of the Athabasca Oil Sands Project venture (Shell Canada Energy, Chevron Canada Limited, Marathon Oil Canada Corporation), announced that it was proceeding to construct the Quest Carbon Capture and Storage (CCS) project near Fort Saskatchewan. Quest is the world's first large-scale commercial application of CCS at an oil sands operation, and it is now capturing more than one million tonnes of CO2 per year from the Scotford Upgrader. It is a fully integrated project, involving CO2 capture at the bitumen upgrader, transportation along a 65 km pipeline, and CO2 storage in a deep saline aquifer (the Basal Cambrian Sands). Construction was completed in August 2015, and the Quest project was certified for commercial operation in September 2015. The Measurement, Monitoring and Verification (MMV) program for Quest is comprehensive, with a variety of technologies being used to monitor the atmosphere, hydrosphere, biosphere and geosphere. These include a Lightsource system for atmospheric monitoring, extensive groundwater sampling, DAS VSPs to assess the development of the CO2 plume, a microseismic array to measure any induced seismic activity, and temperature and pressure gauges for reservoir monitoring. Over two years of operations, this program has been optimized to address key risks while improving operational efficiency. Quest has now successfully captured and stored more than 2 million tonnes of CO2 with no MMV indications of any storage issues.

A shell approach for fibrous reinforcement forming simulations

NASA Astrophysics Data System (ADS)

Liang, B.; Colmars, J.; Boisse, P.

2018-05-01

Because of the slippage between fibers, the basic assumptions of classical plate and shell theories are not verified by fiber reinforcement during a forming. However, simulations of reinforcement forming use shell finite elements when wrinkles development is important. A shell formulation is proposed for the forming simulations of continuous fiber reinforcements. The large tensile stiffness leads to the quasi inextensibility in the fiber directions. The fiber bending stiffness determines the curvature of the reinforcement. The calculation of tensile and bending virtual works are based on the precise geometry of the single fiber. Simulations and experiments are compared for different reinforcements. It is shown that the proposed fibrous shell approach not only correctly simulates the deflections but also the rotations of the through thickness material normals.

Enhancing electrical energy storage capability of dielectric polymer nanocomposites via the room temperature Coulomb blockade effect of ultra-small platinum nanoparticles.

PubMed

Wang, Liwei; Huang, Xingyi; Zhu, Yingke; Jiang, Pingkai

2018-02-14

Introducing a high dielectric constant (high-k) nanofiller into a dielectric polymer is the most common way to achieve flexible nanocomposites for electrostatic energy storage devices. However, the significant decrease of breakdown strength and large increase of dielectric loss has long been known as the bottleneck restricting the enhancement of practical energy storage capability of the nanocomposites. In this study, by introducing ultra-small platinum (<2 nm) nanoparticles, high-k polymer nanocomposites with high breakdown strength and low dielectric loss were prepared successfully. Core-shell structured polydopamine@BaTiO 3 (PDA@BT) and core-satellite ultra-small platinum decorated PDA@BT (Pt@PDA@BT) were used as nanofillers. Compared with PDA@BT nanocomposites, the maximum discharged energy density of the Pt@PDA@BT nanocomposites is increased by nearly 70% because of the improved energy storage efficiency. This research provides a simple, promising and unique way to enhance energy storage capability of high-k polymer nanocomposites.

Photoionization of Ne Atoms and Ne + Ions Near the K Edge: PrecisionSpectroscopy and Absolute Cross-sections

DOE PAGES

Müller, Alfred; Bernhardt, Dietrich; Borovik, Alexander; ...

2017-02-17

Single, double, and triple photoionization of Ne + ions by single photons have been investigated at the synchrotron radiation source PETRA III in Hamburg, Germany. Absolute cross-sections were measured by employing the photon-ion merged-beams technique. Photon energies were between about 840 and 930 eV, covering the range from the lowest-energy resonances associated with the excitation of one single K-shell electron up to double excitations involving one K- and one L-shell electron, well beyond the K-shell ionization threshold. Also, photoionization of neutral Ne was investigated just below the K edge. The chosen photon energy bandwidths were between 32 and 500 meV,more » facilitating the determination of natural line widths. The uncertainty of the energy scale is estimated to be 0.2 eV. For comparison with existing theoretical calculations, astrophysically relevant photoabsorption cross-sections were inferred by summing the measured partial ionization channels. Discussion of the observed resonances in the different final ionization channels reveals the presence of complex Auger-decay mechanisms. The ejection of three electrons from the lowest K-shell-excited Ne + (1s2s 2p 6 2S 1/2) level, for example, requires cooperative interaction of at least four electrons.« less

Summary of Group Development and Testing for Single Shell Tank Closure at Hanford

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harbour, John, R.

2005-04-28

This report is a summary of the bench-scale and large scale experimental studies performed by Savannah River National Laboratory for CH2M HILL to develop grout design mixes for possible use in producing fill materials as a part of Tank Closure of the Single-Shell Tanks at Hanford. The grout development data provided in this report demonstrates that these design mixes will produce fill materials that are ready for use in Hanford single shell tank closure. The purpose of this report is to assess the ability of the proposed grout specifications to meet the current requirements for successful single shell tank closuremore » which will include the contracting of services for construction and operation of a grout batch plant. The research and field experience gained by SRNL in the closure of Tanks 17F and 20F at the Savannah River Site was leveraged into the grout development efforts for Hanford. It is concluded that the three Hanford grout design mixes provide fill materials that meet the current requirements for successful placement. This conclusion is based on the completion of recommended testing using Hanford area materials by the operators of the grout batch plant. This report summarizes the regulatory drivers and the requirements for grout mixes as tank fill material. It is these requirements for both fresh and cured grout properties that drove the development of the grout formulations for the stabilization, structural and capping layers.« less

Grafting Modification of the Reactive Core-Shell Particles to Enhance the Toughening Ability of Polylactide

PubMed Central

Li, Zhaokun; Song, Shixin; Zhao, Xuanchen; Lv, Xue; Sun, Shulin

2017-01-01

In order to overcome the brittleness of polylactide (PLA), reactive core-shell particles (RCS) with polybutadiene as core and methyl methacrylate-co-styrene-co-glycidyl methacrylate as shell were prepared to toughen PLA. Tert-dodecyl mercaptan (TDDM) was used as chain transfer agent to modify the grafting properties (such as grafting degree, shell thickness, internal and external grafting) of the core-shell particles. The introduction of TDDM decreased the grafting degree, shell thickness and the Tg of the core phase. When the content of TDDM was lower than 1.15%, the RCS particles dispersed in the PLA matrix uniformly—otherwise, agglomeration took place. The addition of RCS particles induced a higher cold crystallization temperature and a lower melting temperature of PLA which indicated the decreased crystallization ability of PLA. Dynamic mechanical analysis (DMA) results proved the good miscibility between PLA and the RCS particles and the increase of TDDM in RCS induced higher storage modulus of PLA/RCS blends. Suitable TDDM addition improved the toughening ability of RCS particles for PLA. In the present research, PLA/RCS-T4 (RCS-T4: the reactive core-shell particles with 0.76 wt % TDDM addition) blends displayed much better impact strength than other blends due to the easier cavitation/debonding ability and good dispersion morphology of the RCS-T4 particles. When the RCS-T4 content was 25 wt %, the impact strength of PLA/RCS-T4 blend reached 768 J/m, which was more than 25 times that of the pure PLA. PMID:28813019

Semipermeable Elastic Microcapsules for Gas Capture and Sensing.

PubMed

Nabavi, Seyed Ali; Vladisavljević, Goran T; Gu, Sai; Manović, Vasilije

2016-09-27

Monodispersed microcapsules for gas capture and sensing were developed consisting of elastic semipermeable polymer shells of tunable size and thickness and pH-sensitive, gas selective liquid cores. The microcapsules were produced using glass capillary microfluidics and continuous on-the-fly photopolymerization. The inner fluid was 5-30 wt % K2CO3 solution with m-cresol purple, the middle fluid was a UV-curable liquid silicon rubber containing 0-2 wt % Dow Corning 749 fluid, and the outer fluid was aqueous solution containing 60-70 wt % glycerol and 0.5-2 wt % stabilizer (poly(vinyl alcohol), Tween 20, or Pluronic F-127). An analytical model was developed and validated for prediction of the morphology of the capsules under osmotic stress based on the shell properties and the osmolarity of the storage and core solutions. The minimum energy density and UV light irradiance needed to achieve complete shell polymerization were 2 J·cm(-2) and 13.8 mW·cm(-2), respectively. After UV exposure, the curing time for capsules containing 0.5 wt % Dow Corning 749 fluid in the middle phase was 30-40 min. The CO2 capture capacity of 30 wt % K2CO3 capsules was 1.6-2 mmol/g depending on the capsule size and shell thickness. A cavitation bubble was observed in the core when the internal water was abruptly removed by capillary suction, whereas a gradual evaporation of internal water led to buckling of the shell. The shell was characterized using TGA, DSC, and FTIR. The shell degradation temperature was 450-460 °C.

Grafting Modification of the Reactive Core-Shell Particles to Enhance the Toughening Ability of Polylactide.

PubMed

Li, Zhaokun; Song, Shixin; Zhao, Xuanchen; Lv, Xue; Sun, Shulin

2017-08-16

In order to overcome the brittleness of polylactide (PLA), reactive core-shell particles (RCS) with polybutadiene as core and methyl methacrylate-co-styrene-co-glycidyl methacrylate as shell were prepared to toughen PLA. Tert-dodecyl mercaptan (TDDM) was used as chain transfer agent to modify the grafting properties (such as grafting degree, shell thickness, internal and external grafting) of the core-shell particles. The introduction of TDDM decreased the grafting degree, shell thickness and the T g of the core phase. When the content of TDDM was lower than 1.15%, the RCS particles dispersed in the PLA matrix uniformly-otherwise, agglomeration took place. The addition of RCS particles induced a higher cold crystallization temperature and a lower melting temperature of PLA which indicated the decreased crystallization ability of PLA. Dynamic mechanical analysis (DMA) results proved the good miscibility between PLA and the RCS particles and the increase of TDDM in RCS induced higher storage modulus of PLA/RCS blends. Suitable TDDM addition improved the toughening ability of RCS particles for PLA. In the present research, PLA/RCS-T4 (RCS-T4: the reactive core-shell particles with 0.76 wt % TDDM addition) blends displayed much better impact strength than other blends due to the easier cavitation/debonding ability and good dispersion morphology of the RCS-T4 particles. When the RCS-T4 content was 25 wt %, the impact strength of PLA/RCS-T4 blend reached 768 J/m, which was more than 25 times that of the pure PLA.

Design of epoxy-functionalized Fe3O4@MCM-41 core-shell nanoparticles for enzyme immobilization.

PubMed

Ulu, Ahmet; Ozcan, Imren; Koytepe, Suleyman; Ates, Burhan

2018-05-01

The scope of our research was to prepare the organosilane-modified Fe 3 O 4 @MCM-41 core-shell magnetic nanoparticles, used for L-ASNase immobilization and explored screening of immobilization conditions such as pH, temperature, thermal stability, kinetic parameters, reusability and storage stability. In this content, Fe 3 O 4 core-shell magnetic nanoparticles were prepared via co-precipitation method and coated with MCM-41. Then, Fe 3 O 4 @MCM-41 magnetic nanoparticles were functionalized by (3-glycidyloxypropyl) trimethoxysilane (GPTMS) as an organosilane compound. Subsequently, L-ASNase was covalently immobilized on epoxy-functionalized Fe 3 O 4 @MCM-41 magnetic nanoparticles. The immobilized L-ASNase had greater activity at high pH and temperature values. It also maintained >92% of the initial activity after incubation at 55 °C for 3 h. Regarding kinetic values, immobilized L-ASNase showed a higher Vmax and lower Km compared to native L-ASNase. In addition, it displayed excellent reusability for 12 successive cycles. After 30 days of storage at 4 °C and 25 °C, immobilized L-ASNase retained 54% and 26% of its initial activities while native L-ASNase lost about 68% and 84% of its initial activity, respectively. As a result, the immobilization of L-ASNase onto magnetic nanoparticles may provide an advantage in terms of removal of L-ASNase from reaction media. Copyright © 2018. Published by Elsevier B.V.

Modifying Current Collectors to Produce High Volumetric Energy Density and Power Density Storage Devices.

PubMed

Khani, Hadi; Dowell, Timothy J; Wipf, David O

2018-06-27

We develop zirconium-templated NiO/NiOOH nanosheets on nickel foam and polypyrrole-embedded in exfoliated carbon fiber cloth as complementary electrodes for an asymmetric battery-type supercapacitor device. We achieve high volumetric energy and power density by the modification of commercially available current collectors (CCs). The modified CCs provide the source of active material, actively participate in the charge storage process, provide a larger surface area for active material loading, need no additional binders or conductive additives, and retain the ability to act as the CC. Nickel foam (NF) CCs are modified by use of a soft-templating/solvothermal treatment to generate NiO/NiOOH nanosheets, where the NF is the source of Ni for the synthesis. Carbon-fiber cloth (CFC) CCs are modified by an electrochemical oxidation/reduction process to generate exfoliated core-shell structures (ECFC). Electropolymerization of pyrrole into the shell structure produces polypyrrole embedded in exfoliated core-shell material (PPy@rECFC). Battery-type supercapacitor devices are produced with NiO/NiOOH@NF and PPy@rECFC as positive and negative electrodes, respectively, to demonstrate the utility of this approach. Volumetric energy densities for the full-cell device are in the range of 2.60-4.12 mWh cm -3 with corresponding power densities in the range of 9.17-425.58 mW cm -3 . This is comparable to thin-film lithium-ion batteries (0.3-10 mWh cm -3 ) and better than some commercial supercapacitors (<1 mWh cm -3 ). 1 The energy and power density is impressive considering that it was calculated using the entire cell volume (active materials, separator, and both CCs). The full-cell device is highly stable, retaining 96% and 88% of capacity after 2000 and 5000 cycles, respectively. These results demonstrate the utility of directly modifying the CCs and suggest a new method to produce high volumetric energy density and power density storage devices.

Solar hot water system installed at Days Inn Motel, Dallas, Texas (Forrest Lane)

NASA Technical Reports Server (NTRS)

1980-01-01

The solar system was designed to provide 65 percent of the total Domestic Hot Water (DHW) demand. The liquid flat plate (water) collector (1,000 square feet) system automatically drains into the 1,000 gallon steel storage tank located in the mechanical room when the pump is not running. Heat is transferred from the storage tank to DHW tanks through a tube and shell heat exchanger. A circulating pump between the DHW tanks and the heat exchanger enables solar heated water to help make DHW tank standby losses. All pumps are controlled by differential temperature.

Deriving the Distribution of Conjunctions.

ERIC Educational Resources Information Center

Zoerner, Ed

1994-01-01

This paper proposes an explanation for the limited possibilities of realized conjunctions in multitermed coordinations. It argues that conjunction "&" heads a fully articulated phrase (&P), which can iterate &P shells, similar to "V" in Larson's (1988) VP-shell hypothesis. This structure enables a single & to unify any number of conjuncts, and…

Periodicity and Some Graphical Insights on the Tendency toward Empty, Half-full, and Full Subshells.

ERIC Educational Resources Information Center

Rich, Ronald L.; Suter, Robert W.

1988-01-01

Investigates ground state electron configurations for some common elements using graphical methods. Bases observed tendencies on following ideas: "occupancy of differing shells, occupancy of differing subshells within a given shell, double occupancy vs. single occupancy of an orbital, and quantum-mechanical exchange." (ML)

Atomistic tight-binding theory of excitonic splitting energies in CdX(X = Se, S and Te)/ZnS core/shell nanocrystals

NASA Astrophysics Data System (ADS)

Sukkabot, Worasak; Pinsook, Udomsilp

2017-01-01

Using the atomistic tight-binding theory (TB) and a configuration interaction description (CI), we numerically compute the excitonic splitting of CdX(X = Se, S and Te)/ZnS core/shell nanocrystals with the objective to explain how types of the core materials and growth shell thickness can provide the detailed manipulation of the dark-dark (DD), dark-bright (DB) and bright-bright (BB) excitonic splitting, beneficial for the active application of quantum information. To analyze the splitting of the excitonic states, the optical band gaps, ground-state wave function overlaps and atomistic electron-hole interactions tend to be numerically demonstrated. Based on the atomistic computations, the single-particle and excitonic gaps are mainly reduced with the increasing ZnS shell thickness owing to the quantum confinement. In the range of the higher to lower energies, the order of the single-particle gaps is CdSe/ZnS, CdS/ZnS and CdTe/ZnS core/shell nanocrystals, while one of the excitonic gaps is CdS/ZnS, CdSe/ZnS and CdTe/ZnS core/shell nanocrystals because of the atomistic electron-hole interaction. The strongest electron-hole interactions are mainly observed in CdSe/ZnS core/shell nanocrystals. In addition, the computational results underline that the energies of the dark-dark (DD), dark-bright (DB) and bright-bright (BB) excitonic splitting are generally reduced with the increasing ZnS growth shell thickness as described by the trend of the electron-hole exchange interaction. The high-to-low splitting of the excitonic states is demonstrated in CdSe/ZnS, CdTe/ZnS and CdS/ZnS core/shell nanocrystals because of the fashion in the electron-hole exchange interaction and overlaps of the electron-hole wave functions. As the resulting calculations, it is expected that CdS/ZnS core/shell nanocrystals are the best candidates to be the source of entangled photons. Finally, the comprehensive information on the excitonic splitting can enable the use of suitable core/shell nanocrystals for the entangled photons in the application of quantum information.

Hydrological analysis of single and dual storage systems for stormwater harvesting.

PubMed

Brodie, I M

2008-01-01

As stormwater flows are intermittent, the requirement to store urban runoff is important to the design of a stormwater re-use scheme. In many urban areas, the space available to provide storage is limited and thus the need to optimise the storage volume becomes critical. This paper will highlight the advantages and disadvantages of two different approaches of providing storage: 1) a single shallow storage (0.5 m depth) in which stormwater capture and a balanced release to supply users is provided by the one unit; and 2) a dual system in which the functions of stormwater capture and supply release are provided by two separate deeper storage units (2 m depth). The comparison between the two strategies is supported by water balance modelling assessing the supply reliability and storage volume requirements for both options. Above a critical volumetric capacity, the supply yield of a dual storage system is higher than that from a single storage of equal volume mainly because of a smaller assumed footprint. The single storage exhibited greater evaporation loss and is more susceptible to algae blooms due to long water residence times. Results of the comparison provide guidance to the design of more efficient storages associated with stormwater harvesting systems. Copyright IWA Publishing 2008.

Linear phase encoding for holographic data storage with a single phase-only spatial light modulator.

PubMed

Nobukawa, Teruyoshi; Nomura, Takanori

2016-04-01

A linear phase encoding is presented for realizing a compact and simple holographic data storage system with a single spatial light modulator (SLM). This encoding method makes it possible to modulate a complex amplitude distribution with a single phase-only SLM in a holographic storage system. In addition, an undesired light due to the imperfection of an SLM can be removed by spatial frequency filtering with a Nyquist aperture. The linear phase encoding is introduced to coaxial holographic data storage. The generation of a signal beam using linear phase encoding is experimentally verified in an interferometer. In a coaxial holographic data storage system, single data recording, shift selectivity, and shift multiplexed recording are experimentally demonstrated.

Bandgap Engineering of InP QDs Through Shell Thickness and Composition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dennis, Allison M.; Mangum, Benjamin D.; Piryatinski, Andrei

2012-06-21

Fields as diverse as biological imaging and telecommunications utilize the unique photophysical and electronic properties of nanocrystal quantum dots (NQDs). The development of new NQD compositions promises material properties optimized for specific applications, while addressing material toxicity. Indium phosphide (InP) offers a 'green' alternative to the traditional cadmium-based NQDs, but suffers from extreme susceptibility to oxidation. Coating InP cores with more stable shell materials significantly improves nanocrystal resistance to oxidation and photostability. We have investigated several new InP-based core-shell compositions, correlating our results with theoretical predictions of their optical and electronic properties. Specifically, we can tailor the InP core-shell QDsmore » to a type-I, quasi-type-II, or type-II bandgap structure with emission wavelengths ranging from 500-1300 nm depending on the shell material used (ZnS, ZnSe, CdS, or CdSe) and the thickness of the shell. Single molecule microscopy assessments of photobleaching and blinking are used to correlate NQD properties with shell thickness.« less

Modeling the gain of inner-shell X-ray laser transitions in neon, argon, and copper driven by X-ray free electron laser radiation using photo-ionization and photo-excitation processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nilsen, Joseph

2015-12-16

Using an X-ray free electron laser (XFEL) at 960 eV to photo-ionize the 1s electron in neutral neon followed by lasing on the 2p-1s transition in singly-ionized neon, an inner-shell X-ray laser was demonstrated at 849 eV in singly-ionized neon gas several years ago. It took decades to demonstrate this scheme, because it required a very strong X-ray source that could photo-ionize the 1s (K shell) electron in neon on a timescale comparable to the intrinsic Auger lifetime in neon of 2 fs. In this paper, we model the neon inner shell X-ray laser under similar conditions to those usedmore » in the XFEL experiments at the SLAC Linac Coherent Light Source (LCLS), and show how we can improve the efficiency of the neon laser and reduce the drive requirements by tuning the XFEL to the 1s-3p transition in neutral neon in order to create gain on the 2p-1s line in neutral neon. We also show how the XFEL could be used to photo-ionize L-shell electrons to drive gain on n = 3–2 transitions in singly-ionized Ar and Cu plasmas. Furthermore, these bright, coherent, and monochromatic X-ray lasers may prove very useful for doing high-resolution spectroscopy and for studying non-linear process in the X-ray regime.« less

Size-Dependent Biexciton Quantum Yields and Carrier Dynamics of Quasi-Two-Dimensional Core/Shell Nanoplatelets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Xuedan; Diroll, Benjamin T.; Cho, Wooje

Quasi-two-dimensional nanoplatelets (NPLs) possess fundamentally different excitonic properties from zero-dimensional quantum dots. We study lateral size-dependent photon emission statistics and carrier dynamics of individual NPLs using second-order photon correlation (g( 2)(τ)) spectroscopy and photoluminescence (PL) intensity-dependent lifetime analysis. Room-temperature radiative lifetimes of NPLs can be derived from maximum PL intensity periods in PL time traces. It first decreases with NPL lateral size and then stays constant, deviating from the electric dipole approximation. Analysis of the PL time traces further reveals that the single exciton quantum yield in NPLs decreases with NPL lateral size and increases with protecting shell thickness, indicatingmore » the importance of surface passivation on NPL emission quality. Second-order photon correlation (g( 2)(τ)) studies of single NPLs show that the biexciton quantum yield is strongly dependent on the lateral size and single exciton quantum yield of the NPLs. In large NPLs with unity single exciton quantum yield, the corresponding biexciton quantum yield can reach unity. In conclusion, these findings reveal that by careful growth control and core–shell material engineering, NPLs can be of great potential for light amplification and integrated quantum photonic applications.« less

Size-Dependent Biexciton Quantum Yields and Carrier Dynamics of Quasi-Two-Dimensional Core/Shell Nanoplatelets

DOE PAGES

Ma, Xuedan; Diroll, Benjamin T.; Cho, Wooje; ...

2017-08-08

Quasi-two-dimensional nanoplatelets (NPLs) possess fundamentally different excitonic properties from zero-dimensional quantum dots. We study lateral size-dependent photon emission statistics and carrier dynamics of individual NPLs using second-order photon correlation (g( 2)(τ)) spectroscopy and photoluminescence (PL) intensity-dependent lifetime analysis. Room-temperature radiative lifetimes of NPLs can be derived from maximum PL intensity periods in PL time traces. It first decreases with NPL lateral size and then stays constant, deviating from the electric dipole approximation. Analysis of the PL time traces further reveals that the single exciton quantum yield in NPLs decreases with NPL lateral size and increases with protecting shell thickness, indicatingmore » the importance of surface passivation on NPL emission quality. Second-order photon correlation (g( 2)(τ)) studies of single NPLs show that the biexciton quantum yield is strongly dependent on the lateral size and single exciton quantum yield of the NPLs. In large NPLs with unity single exciton quantum yield, the corresponding biexciton quantum yield can reach unity. In conclusion, these findings reveal that by careful growth control and core–shell material engineering, NPLs can be of great potential for light amplification and integrated quantum photonic applications.« less

PLGA-lecithin-PEG core-shell nanoparticles for controlled drug delivery.

PubMed

Chan, Juliana M; Zhang, Liangfang; Yuet, Kai P; Liao, Grace; Rhee, June-Wha; Langer, Robert; Farokhzad, Omid C

2009-03-01

Current approaches to encapsulate and deliver therapeutic compounds have focused on developing liposomal and biodegradable polymeric nanoparticles (NPs), resulting in clinically approved therapeutics such as Doxil/Caelyx and Genexol-PM, respectively. Our group recently reported the development of biodegradable core-shell NP systems that combined the beneficial properties of liposomal and polymeric NPs for controlled drug delivery. Herein we report the parameters that alter the biological and physicochemical characteristics, stability, drug release properties and cytotoxicity of these core-shell NPs. We further define scalable processes for the formulation of these NPs in a reproducible manner. These core-shell NPs consist of (i) a poly(D,L-lactide-co-glycolide) hydrophobic core, (ii) a soybean lecithin monolayer, and (iii) a poly(ethylene glycol) shell, and were synthesized by a modified nanoprecipitation method combined with self-assembly. Preparation of the NPs showed that various formulation parameters such as the lipid/polymer mass ratio and lipid/lipid-PEG molar ratio controlled NP physical stability and size. We encapsulated a model chemotherapy drug, docetaxel, in the NPs and showed that the amount of lipid coverage affected its drug release kinetics. Next, we demonstrated a potentially scalable process for the formulation, purification, and storage of NPs. Finally, we tested the cytotoxicity using MTT assays on two model human cell lines, HeLa and HepG2, and demonstrated the biocompatibility of these particles in vitro. Our data suggest that the PLGA-lecithin-PEG core-shell NPs may be a useful new controlled release drug delivery system.

Binder-free ZnO@ZnSnO3 quantum dots core-shell nanorod array anodes for lithium-ion batteries

NASA Astrophysics Data System (ADS)

Tan, Hsiang; Cho, Hsun-Wei; Wu, Jih-Jen

2018-06-01

In this work, ZnSnO3 quantum dots (QDs), instead of commonly used conductive carbon, are grown on the ZnO nanorod (NR) array to construct the binder-free ZnO@ZnSnO3 QDs core-shell NR array electrode on carbon cloth for lithium-ion battery. The ZnO@ZnSnO3 QDs core-shell NR array electrode exhibits excellent lithium storage performance with an improved cycling performance and superior rate capability compared to the ZnO NR array electrode. At a current density of 200 mAg-1, 15.8% capacity loss is acquired in the ZnO@ZnSnO3 QDs core-shell NR array electrode after 110 cycles with capacity retention of 1073 mAhg-1. Significant increases in reversible capacities from 340 to 545 mAhg-1 and from 95 to 390 mAhg-1 at current densities of 1000 and 2000 mAg-1, respectively, are achieved as the ZnO NR arrays are coated with the ZnSnO3 QD shells. The remarkably improved electrochemical performances result from that the configuration of binder-free ZnO@ZnSnO3 QDs core-shell NR array electrode not only facilitates the charge transfer through the solid electrolyte interface and the electronic/ionic conduction boundary as well as lithium ion diffusion but also effectively accommodates the volume change during repeated charge/discharge processes.

Application of the Kishimoto-Tamura boson expansion theory to a single-j shell model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, C.T.; Pedrocchi, V.G.; Tamura, T.

1985-11-01

The boson expansion theory of Kishimoto and Tamura is applied to a single-j shell model. It is shown that this theory is quite accurate, giving results that agree very closely with those of the exact fermion calculations. The fast convergence of the boson expansion is also demonstrated. A critical discussion is then made of an earlier paper by Arima, in which he stated that the Kishimoto-Tamura theory gives rise to very poor numerical results. The source of the trouble encountered by Arima is unmasked.

Low temperature oxidation synthesis of carbon encapsulated Cr2O3 nanocrystals and its lithium storage performance

NASA Astrophysics Data System (ADS)

Zhou, Yun; Liu, Boyang; Shao, Yingfeng; Fan, Chunhua; Fan, Runhua; Wen, Bosheng

A highly efficient and convenient strategy is developed for the one-step in-situ synthesis of carbon encapsulated Cr2O3 nanocrystals with core-shell structure (Cr2O3@C). The explosive reaction of chromocene with ammonium persulfate in an autoclave at 200∘C is crucial for the formation of this nanostructure. The Cr2O3 nanocrystals have a diameter of 5 to 20nm, which are entirely encapsulated by the amorphous carbon shell. The Cr2O3@C anode can retain a stable reversible capacity of 397mAhg-1 after 50 cycles at a current density of 119mA g-1.

Emission Behavior of Fluorescently Labeled Silver Nanoshell: Enhanced Self-Quenching by Metal Nanostructure.

PubMed

Zhang, Jian; Fu, Yi; Lakowicz, Joseph R

2007-02-08

Labeled silica beads with an average diameter of 100 nm were synthesized by incorporating with 20-600 μM Ru(bpy)(3) (2+) complexes. Silver shells were deposited on the beads layer-by-layer with the shell thickness of 5-50 nm. The emission band became narrower and the intensity was enhanced depending on the shell thickness. Self-quenching of the probe was observed at high concentration. Poisson statistics were employed to analyze self-quenching of the fluorophores. The estimated quenching distance was extended from 6 to 16 nm with shell growth from 0 to 50 nm. Moreover, the silver shells were also labeled with Rhodamine 6G. Fluorescence enhancement and reduced lifetime were also observed for silver-silica shell containing R6G. We found that by adjustment of probe concentration and silver shell thickness, a Ru(bpy)(3) (2+)-labeled particle could be 600 times brighter than an isolated Ru(bpy)(3) (2+) molecule. We expect labeled metal core-shell structures can become useful probes for high sensitivity and/or single particle assay.

Resource Letter NSM-1: New insights into the nuclear shell model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dean, David Jarvis; Hamilton, J. H.

2011-01-01

This Resource Letter provides a guide to the literature on the spherical shell model as applied to nuclei. The nuclear shell model describes the structure of nuclei starting with a nuclear core developed by the classical neutron and proton magic numbers N,Z=2,8,20,28,50,82, 126, where gaps occur in the single-particle energies as a shell is filled, and the interactions of valence nucleons that reside beyond that core. Various modern extensions of this model for spherical nuclei are likewise described. Significant extensions of the nuclear shell model include new magic numbers for spherical nuclei and now for deformed nuclei as well. Whenmore » both protons and neutrons have shell gaps at the same spherical or deformed shapes, they can reinforce each other to give added stability to that shape and lead to new magic numbers. The vanishings of the classical spherical shell model energy gaps and magic numbers in new neutron-rich nuclei are described. Spherical and deformed shell gaps are seen to be critical for the existence of elements with Z > 100.« less

Core-shell Au-Pd nanoparticles as cathode catalysts for microbial fuel cell applications

PubMed Central

Yang, Gaixiu; Chen, Dong; Lv, Pengmei; Kong, Xiaoying; Sun, Yongming; Wang, Zhongming; Yuan, Zhenhong; Liu, Hui; Yang, Jun

2016-01-01

Bimetallic nanoparticles with core-shell structures usually display enhanced catalytic properties due to the lattice strain created between the core and shell regions. In this study, we demonstrate the application of bimetallic Au-Pd nanoparticles with an Au core and a thin Pd shell as cathode catalysts in microbial fuel cells, which represent a promising technology for wastewater treatment, while directly generating electrical energy. In specific, in comparison with the hollow structured Pt nanoparticles, a benchmark for the electrocatalysis, the bimetallic core-shell Au-Pd nanoparticles are found to have superior activity and stability for oxygen reduction reaction in a neutral condition due to the strong electronic interaction and lattice strain effect between the Au core and the Pd shell domains. The maximum power density generated in a membraneless single-chamber microbial fuel cell running on wastewater with core-shell Au-Pd as cathode catalysts is ca. 16.0 W m−3 and remains stable over 150 days, clearly illustrating the potential of core-shell nanostructures in the applications of microbial fuel cells. PMID:27734945

Core-shell TiO2@ZnO nanorods for efficient ultraviolet photodetection

NASA Astrophysics Data System (ADS)

Panigrahi, Shrabani; Basak, Durga

2011-05-01

Core-shell TiO2@ZnO nanorods (NRs) have been fabricated by a simple two step method: growth of ZnO NRs' array by an aqueous chemical technique and then coating of the NRs with a solution of titanium isopropoxide [Ti(OC3H7)4] followed by a heating step to form the shell. The core-shell nanocomposites are composed of single-crystalline ZnO NRs, coated with a thin TiO2 shell layer obtained by varying the number of coatings (one, three and five times). The ultraviolet (UV) emission intensity of the nanocomposite is largely quenched due to an efficient electron-hole separation reducing the band-to-band recombinations. The UV photoconductivity of the core-shell structure with three times TiO2 coating has been largely enhanced due to photoelectron transfer between the core and the shell. The UV photosensitivity of the nanocomposite becomes four times larger while the photocurrent decay during steady UV illumination has been decreased almost by 7 times compared to the as-grown ZnO NRs indicating high efficiency of these core-shell structures as UV sensors.

Effect of Chitin Isolated from Crustaceans and Cephalopods on Denaturation of Fish Myofibrillar Protein and the State of Water during Frozen Storage

NASA Astrophysics Data System (ADS)

Yamashita, Yasumitsu; Zhang, Nong; Nozaki, Yukinori

The effect of chitin hydrolysate made from shell of crustaceans and cartilage of cephalopods on the denaturation and the state of water of lizard fish myofibrillar protein (Mf) during frozen storage at -250°C for 120 days were investigated. 5.0% chitin hydrolysate (dried matter) added Mf samples were frozen at -25°C and storage for 120 days, and the change of inactivation of Mf Ca-ATPase and the change of unfrozen water in Mf were examined during the frozen storage. The decrease of Mf Ca-ATPase during frozen storage were slow by addition of chitin hydrolysate. The amount of unfrozen water in Mf were increased by addition of chitin hydrolysate, and decreaced gradually during frozen storage. On the other hand, the amount of unfrozen water of the control were decreaced suddenly during frozen storage. Above results suggest that chitin hydrolysate has cryoprotective effect on Mf. It is guessed that the mechanism of cryoprotective effect of chitin hydrolysate may be caused by an interaction between hydration sphere of Mf and equatorial OH groups in the molecular structure of chitin hydrolysate.

Estimation of turgor pressure through comparison between single plant cell and pressurized shell mechanics

NASA Astrophysics Data System (ADS)

Durand-Smet, P.; Gauquelin, E.; Chastrette, N.; Boudaoud, A.; Asnacios, A.

2017-10-01

While plant growth is well known to rely on turgor pressure, it is challenging to quantify the contribution of turgor pressure to plant cell rheology. Here we used a custom-made micro-rheometer to quantify the viscoelastic behavior of isolated plant cells while varying their internal turgor pressure. To get insight into how plant cells adapt their internal pressure to the osmolarity of their medium, we compared the mechanical behavior of single plant cells to that of a simple, passive, pressurized shell: a soccer ball. While both systems exhibited the same qualitative behavior, a simple mechanical model allowed us to quantify turgor pressure regulation at the single cell scale.

Probing the Single-Particle Character of Rotational States in F 19 Using a Short-Lived Isomeric Beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santiago-Gonzalez, D.; Auranen, K.; Avila, M. L.

2018-03-01

A beam containing a substantial component of both the J(pi) = 5(+), T-1/2 = 162 ns isomeric state of F-18 and its 1(+), 109.77-min ground state is utilized to study members of the ground-state rotational band in F-19 through the neutron transfer reaction (d,p) in inverse kinematics. The resulting spectroscopic strengths confirm the single-particle nature of the 13/2(+) band-terminating state. The agreement between shell-model calculations using an interaction constructed within the sd shell, and our experimental results reinforces the idea of a single-particle-collective duality in the descriptions of the structure of atomic nuclei.

Iridium-decorated palladium-platinum core-shell catalysts for oxygen reduction reaction in proton exchange membrane fuel cell.

PubMed

Wang, Chen-Hao; Hsu, Hsin-Cheng; Wang, Kai-Ching

2014-08-01

Carbon-supported Pt, Pd, Pd-Pt core-shell (Pt(shell)-Pd(core)/C) and Ir-decorated Pd-Pt core-shell (Ir-decorated Pt(shell)-Pd(core)/C) catalysts were synthesized, and their physical properties, electrochemical behaviors, oxygen reduction reaction (ORR) characteristics and proton exchange membrane fuel cell (PEMFC) performances were investigated herein. From the XRD patterns and TEM images, Ir-decorated Pt(shell)-Pd(core)/C has been confirmed that Pt was deposited on the Pd nanoparticle which had the core-shell structure. Ir-decorated Pt(shell)-Pd(core)/C has more positive OH reduction peak than Pt/C, which is beneficial to weaken the binding energy of Pt-OH during the ORR. Thus, Ir-decorated Pt(shell)-Pd(core)/C has higher ORR activity than Pt/C. The maximum power density of H2-O2 PEMFC using Ir-decorated Pt(shell)-Pd(core)/C is 792.2 mW cm(-2) at 70°C, which is 24% higher than that using Pt/C. The single-cell accelerated degradation test of PEMFC using Ir-decorated Pt(shell)-Pd(core)/C shows good durability by the potential cycling of 40,000 cycles. This study concludes that Ir-decorated Pt(shell)-Pd(core)/C has the low Pt content, but it can facilitate the low-cost and high-efficient PEMFC. Copyright © 2013 Elsevier Inc. All rights reserved.

Ocean acidification alters the material properties of Mytilus edulis shells

PubMed Central

Fitzer, Susan C.; Zhu, Wenzhong; Tanner, K. Elizabeth; Phoenix, Vernon R.; Kamenos, Nicholas A.; Cusack, Maggie

2015-01-01

Ocean acidification (OA) and the resultant changing carbonate saturation states is threatening the formation of calcium carbonate shells and exoskeletons of marine organisms. The production of biominerals in such organisms relies on the availability of carbonate and the ability of the organism to biomineralize in changing environments. To understand how biomineralizers will respond to OA the common blue mussel, Mytilus edulis, was cultured at projected levels of pCO2 (380, 550, 750, 1000 µatm) and increased temperatures (ambient, ambient plus 2°C). Nanoindentation (a single mussel shell) and microhardness testing were used to assess the material properties of the shells. Young's modulus (E), hardness (H) and toughness (KIC) were measured in mussel shells grown in multiple stressor conditions. OA caused mussels to produce shell calcite that is stiffer (higher modulus of elasticity) and harder than shells grown in control conditions. The outer shell (calcite) is more brittle in OA conditions while the inner shell (aragonite) is softer and less stiff in shells grown under OA conditions. Combining increasing ocean pCO2 and temperatures as projected for future global ocean appears to reduce the impact of increasing pCO2 on the material properties of the mussel shell. OA may cause changes in shell material properties that could prove problematic under predation scenarios for the mussels; however, this may be partially mitigated by increasing temperature. PMID:25540244

Coupled mixed-field laminate theory and finite element for smart piezoelectric composite shell structures

NASA Technical Reports Server (NTRS)

Saravanos, Dimitris A.

1996-01-01

Mechanics for the analysis of laminated composite shells with piezoelectric actuators and sensors are presented. A new mixed-field laminate theory for piezoelectric shells is formulated in curvilinear coordinates which combines single-layer assumptions for the displacements and a layerwise representation for the electric potential. The resultant coupled governing equations for curvilinear piezoelectric laminates are described. Structural mechanics are subsequently developed and an 8-node finite-element is formulated for the static and dynamic analysis of adaptive composite structures of general laminations containing piezoelectric layers. Evaluations of the method and comparisons with reported results are presented for laminated piezoelectric-composite plates, a closed cylindrical shell with a continuous piezoceramic layer and a laminated composite semi-circular cantilever shell with discrete cylindrical piezoelectric actuators and/or sensors.

Polar wander of an ice shell on Europa

NASA Technical Reports Server (NTRS)

Ojakangas, Gregory W.; Stevenson, David J.

1989-01-01

The present consideration of a hypothesized ice shell around Europa, which is decoupled from the silicate core by a liquid water layer and possesses a spatially varying thermal equilibrium thickness profile, proceeds through the development of equations for variations in the inertia tensor of a body when second-harmonic-degree topography is added to the crustal base. Attention is given to a realistic model in which the shell and ocean are assumed to undergo reorientations as a single entity independently of the core, but subject to viscous dissipation within the shell. Shell friction is in this case noted to preclude polar wander, unless a low conductivity regolith increases the near-surface temperature by a few tens of degrees C; the ice beneath the regolith would then behave viscously on the time-scale of polar wander.

Using Encapsulated Phase Change Material in Thermal Energy Storage for Baseload Concentrating Solar Power (EPCM-TES)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathur, Anoop

2013-12-15

Terrafore successfully demonstrated and optimized the manufacturing of capsules containing phase-changing inorganic salts. The phase change was used to store thermal energy collected from a concentrating solar-power plant as latent heat. This latent heat, in addition to sensible heat increased the energy density (energy stored per unit weight of salt) by over 50%, thus requiring 40% less salt and over 60% less capsule container. Therefore, the cost to store high-temperature thermal energy collected in a concentrating solar power plant will be reduced by almost 40% or more, as compared to conventional two-tank, sensible-only storage systems. The cost for thermal energymore » storage (TES) system is expected to achieve the Sun Shot goal of $15 per kWh(t). Costs associated with poor heat-transfer in phase change materials (PCM) were also eliminated. Although thermal energy storage that relies on the latent heat of fusion of PCM improves energy density by as much as 50%, upon energy discharge the salt freezes and builds on the heat transfer surfaces. Since these salts have low thermal conductivity, large heat-transfer areas, or larger conventional heat-exchangers are needed, which increases costs. By encapsulating PCM in small capsules we have increased the heat transfer area per unit volume of salt and brought the heat transfer fluid in direct contact with the capsules. These two improvements have increased the heat transfer coefficient and boosted heat transfer. The program was successful in overcoming the phenomenon of melt expansion in the capsules, which requires the creation of open volume in the capsules or shell to allow for expansion of the molten salt on melting and is heated above its melting point to 550°C. Under contract with the Department of Energy, Terrafore Inc. and Southwest Research Institute, developed innovative method(s) to economically create the open volume or void in the capsule. One method consists of using a sacrificial polymer coating as the middle layer between the salt prill and the shell material. The selected polymer decomposes at temperatures below the melting point of the salt and forms gases which escape through the pores in the capsule shell thus leaving a void in the capsule. We have demonstrated the process with a commonly used inorganic nitrate salt in a low-cost shell material that can withstand over 10,000 high-temperature thermal cycles, or a thirty-year or greater life in a solar plant. The shell used to encapsulate the salt was demonstrated to be compatible with molten salt heat transfer fluid typically used in CSP plants to temperatures up to 600 °C. The above findings have led to the concept of a cascaded arrangement. Salts with different melting points can be encapsulated using the same recipe and contained in a packed bed by cascading the salt melting at higher melting point at the top over the salt melting at lower melting point towards the bottom of the tank. This cascaded energy storage is required to effectively transfer the sensible heat collected in heat transfer fluids between the operating temperatures and utilize the latent heat of fusion in the salts inside the capsule. Mathematical models indicate that over 90% of the salts will undergo phase change by using three salts in equal proportion. The salts are selected such that the salt at the top of the tank melts at about 15°C below the high operating-temperature, and the salt at the bottom of the tank melts 15°C above the low operating-temperature. The salt in the middle of tank melts in-between the operating temperature of the heat transfer fluid. A cascaded arrangement leads to the capture of 90% of the latent-heat of fusion of salts and their sensible heats. Thus the energy density is increased by over 50% from a sensible-only, two-tank thermal energy storage. Furthermore, the Terrafore cascaded storage method requires only one tank as opposed to the two-tanks used in sensible heat storage. Since heat is transferred from the heat transfer fluid by direct contact with capsules, external heat-exchangers are not required for charging storage. Thus, the cost of the thermal storage system is reduced due to smaller containers and less salt. The optimum salt proportions, their melting temperature and the number of salts in the cascade are determined by raw materials costs and the mathematical model. We estimate the processing cost of the encapsulation to be low, where the major cost of the capsule will be the cost of the phase-change salt(s). Our economic analyses show that the cost of EPCM-TES is about $17.98 per kWh(t), which is about 40% lower than the $28.36 per kWh(t) for a two-tank sensible heat TES for a large scale CSP-TES design. Finally, additional improvements in the heat-transfer fluids, currently in development elsewhere will further improve the energy density to achieve the SunShot goal of $15 per kWh(t).« less

Ignition of deuterium-trtium fuel targets

DOEpatents

Musinski, Donald L.; Mruzek, Michael T.

1991-01-01

A method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom.

Ignition of deuterium-tritium fuel targets

DOEpatents

Musinski, D.L.; Mruzek, M.T.

1991-08-27

Disclosed is a method of igniting a deuterium-tritium ICF fuel target to obtain fuel burn in which the fuel target initially includes a hollow spherical shell having a frozen layer of DT material at substantially uniform thickness and cryogenic temperature around the interior surface of the shell. The target is permitted to free-fall through a target chamber having walls heated by successive target ignitions, so that the target is uniformly heated during free-fall to at least partially melt the frozen fuel layer and form a liquid single-phase layer or a mixed liquid/solid bi-phase layer of substantially uniform thickness around the interior shell surface. The falling target is then illuminated from exteriorly of the chamber while the fuel layer is at substantially uniformly single or bi-phase so as to ignite the fuel layer and release energy therefrom. 5 figures.

Off-shell single-top production at NLO matched to parton showers

DOE PAGES

Frederix, R.; Frixione, S.; Papanastasiou, A. S.; ...

2016-06-06

We study the hadroproduction of a Wb pair in association with a light jet, focusing on the dominant t-channel contribution and including exactly at the matrix-element level all non-resonant and off-shell effects induced by the finite top-quark width. Our simulations are accurate to the next-to-leading order in QCD, and are matched to the Herwig6 and Pythia8 parton showers through the MC@NLO method. We present phenomenological results relevant to the 8 TeV LHC, and carry out a thorough comparison to the case of on-shell t-channel single-top production. Furthermore, we formulate our approach so that it can be applied to the generalmore » case of matrix elements that feature coloured intermediate resonances and are matched to parton showers.« less

Effects of Vacuum Tumbling with Chitosan and Water Soluble Chitosan on the Shelf Life of Catfish Fillets in Refrigerated Storage

USDA-ARS?s Scientific Manuscript database

Chitosan (CH) is mainly made from crustacean shells and has been reported to have a number of functional properties such as its antimicrobial activity, binding action, and antioxidant activity. CH’s water insolubility restricts the use of this compound in some systems. However, when treated with enz...

Automation of peanut drying with a sensor network including an in-shell kernel moisture sensor

USDA-ARS?s Scientific Manuscript database

Peanut drying is an essential task in the processing and handling of peanuts. Peanuts leave the fields with kernel moisture contents > 20% wet basis and need to be dried to < 10.5% w.b. for grading and storage purposes. Current peanut drying processes utilize decision support software based on model...

The Effects of Geometric and Loading Imperfections on the Response and Lower-Bound Buckling Load of a Compression-Loaded Cylindrical Shell

NASA Technical Reports Server (NTRS)

Kriegesmann, Benedikt; Hilburger, Mark W.; Rolfes, Raimund

2012-01-01

Results from a numerical study of the buckling response of a thin-walled compressionloaded isotropic circular cylindrical shell with initial geometric and loading imperfections are used to determine a lower bound buckling load estimate suitable for preliminary design. The lower bound prediction techniques presented herein include an imperfection caused by a lateral perturbation load, an imperfection in the shape of a single stress-free dimple (similar to the lateral pertubation imperfection), and a distributed load imperfection that induces a nonuniform load in the shell. The ABAQUS finite element code is used for the analyses. Responses of the cylinders for selected imperfection amplitudes and imperfection types are considered, and the effect of each imperfection is compared to the response of a geometrically perfect cylinder. The results indicate that compression-loaded shells subjected to a lateral perturbation load or a single dimple imperfection, and a nonuniform load imperfection, exhibit similar buckling behavior and lower bound trends and the predicted lower bounds are much less conservative than the corresponding design recommendation NASA SP-8007 for the design of buckling-critical shells. In addition, the lateral perturbation technique and the distributed load imperfection produce response characteristics that are physically meaningful and can be validated via laboratory testing.

Magnetic carbon nanostructures: microwave energy-assisted pyrolysis vs. conventional pyrolysis.

PubMed

Zhu, Jiahua; Pallavkar, Sameer; Chen, Minjiao; Yerra, Narendranath; Luo, Zhiping; Colorado, Henry A; Lin, Hongfei; Haldolaarachchige, Neel; Khasanov, Airat; Ho, Thomas C; Young, David P; Wei, Suying; Guo, Zhanhu

2013-01-11

Magnetic carbon nanostructures from microwave assisted- and conventional-pyrolysis processes are compared. Unlike graphitized carbon shells from conventional heating, different carbon shell morphologies including nanotubes, nanoflakes and amorphous carbon were observed. Crystalline iron and cementite were observed in the magnetic core, different from a single cementite phase from the conventional process.

The role of radiative de-excitation in the neutralization process of highly charged ions interacting with a single layer of graphene

NASA Astrophysics Data System (ADS)

Schwestka, J.; Wilhelm, R. A.; Gruber, E.; Heller, R.; Kozubek, R.; Schleberger, M.; Facsko, S.; Aumayr, F.

2018-05-01

X-ray emission of slow (<1 a.u.) highly charged Argon and Xenon ions is measured for transmission through a freestanding single layer of graphene. To discriminate against X-ray emission originating from the graphene's support grid a coincidence technique is used. X-ray emission of 75 keV Ar17+ and Ar18+ ions with either one or two K-shell vacancies is recorded. Using a windowless Bruker XFlash detector allows us to measure additionally Ar KLL and KLM Auger electrons and determine the branching ratio of radiative vs. non-radiative decay of Ar K-shell holes. Furthermore, X-ray spectra for 100 keV Xe22+-Xe35+ ions are compared, showing a broad M-line peak for all cases, where M-shell vacancies are present. All these peaks are accompanied by emission lines at still higher energies indicating the presence of a hollow atom during X-ray decay. We report a linear shift of the main M-line peak to higher energies for increasing incident charge state, i.e. increasing number of M-shell holes.

Effectively-truncated large-scale shell-model calculations and nuclei around 100Sn

NASA Astrophysics Data System (ADS)

Gargano, A.; Coraggio, L.; Itaco, N.

2017-09-01

This paper presents a short overview of a procedure we have recently introduced, dubbed the double-step truncation method, which is aimed to reduce the computational complexity of large-scale shell-model calculations. Within this procedure, one starts with a realistic shell-model Hamiltonian defined in a large model space, and then, by analyzing the effective single particle energies of this Hamiltonian as a function of the number of valence protons and/or neutrons, reduced model spaces are identified containing only the single-particle orbitals relevant to the description of the spectroscopic properties of a certain class of nuclei. As a final step, new effective shell-model Hamiltonians defined within the reduced model spaces are derived by way of a unitary transformation of the original large-scale Hamiltonian. A detailed account of this transformation is given and the merit of the double-step truncation method is illustrated by discussing few selected results for 96Mo, described as four protons and four neutrons outside 88Sr. Some new preliminary results for light odd-tin isotopes from A = 101 to 107 are also reported.

Electrical Resistivity Imaging Below Nuclear Waste Tank Farms at the Hanford Site

NASA Astrophysics Data System (ADS)

Rucker, D. F.; Levitt, M. T.

2006-12-01

The Hanford Site, a Department of Energy nuclear processing facility in eastern Washington, contains a complex series of radiological liquid waste disposal and storage facilities. The primary method of interim storage is the use of large single-shelled steel tanks with capacities of up to 3790 m3 (1 million gallons). The tanks are organized below ground into tank farms, with about 12 tanks per farm. The liquid waste within the tanks is primarily comprised of inorganic salts with minor constituents of heavy metals and radiological metals. The electrical properties of the radiological waste are significantly different to that of the surrounding engineered fill and native geologic formations. Over the past 60 years since the earliest tanks have been in use, many have been known to leak. An electrical resistivity survey was conducted within a tank farm to map the extent of the plumes resulting from historic leaks. Traditional surface-based electrical resistivity surveys resulted in unusable data due to the significant subsurface infrastructure that included a network of delivery pipes, wells, fences, and electrical discharge sources . HGI adapted the resistivity technique to include the site infrastructure as transceivers to augment data density and geometry. The results show a distribution of low resistivity values within the farm in areas that match known historic leak sites. The addition of site infrastructure as sensors demonstrates that the electrical resistivity technique can be used in highly industrial sites.

Structural Performance of Advanced Composite Tow-Steered Shells With Cutouts

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Turpin, Jason D.; Stanford, Bret K.; Martin, Robert A.

2014-01-01

The structural performance of two advanced composite tow-steered shells with cutouts, manufactured using an automated fiber placement system, is assessed using both experimental and analytical methods. The shells' fiber orientation angles vary continuously around their circumference from +/-10 degrees on the crown and keel, to +/-45 degrees on the sides. The raised surface features on one shell result from application of all 24 tows during each fiber placement system pass, while the second shell uses the system's tow drop/add capability to achieve a more uniform wall thickness. These unstiffened shells were previously tested in axial compression and buckled elastically. A single cutout, scaled to represent a passenger door on a commercial aircraft, is then machined into one side of each shell. The prebuckling axial stiffnesses and bifurcation buckling loads of the shells with cutouts are also computed using linear finite element structural analyses for initial comparisons with test data. When retested, large deflections were observed around the cutouts, but the shells carried an average of 92 percent of the axial stiffness, and 86 percent of the buckling loads, of the shells without cutouts. These relatively small reductions in performance demonstrate the potential for using tow steering to mitigate the adverse effects of typical design features on the overall structural performance.

Charge and spin control of ultrafast electron and hole dynamics in single CdSe/ZnSe quantum dots

NASA Astrophysics Data System (ADS)

Hinz, C.; Gumbsheimer, P.; Traum, C.; Holtkemper, M.; Bauer, B.; Haase, J.; Mahapatra, S.; Frey, A.; Brunner, K.; Reiter, D. E.; Kuhn, T.; Seletskiy, D. V.; Leitenstorfer, A.

2018-01-01

We study the dynamics of photoexcited electrons and holes in single negatively charged CdSe/ZnSe quantum dots with two-color femtosecond pump-probe spectroscopy. An initial characterization of the energy level structure is performed at low temperatures and magnetic fields of up to 5 T. Emission and absorption resonances are assigned to specific transitions between few-fermion states by a theoretical model based on a configuration interaction approach. To analyze the dynamics of individual charge carriers, we initialize the quantum system into excited trion states with defined energy and spin. Subsequently, the time-dependent occupation of the trion ground state is monitored by spectrally resolved differential transmission measurements. We observe subpicosecond dynamics for a hole excited to the D shell. The energy dependence of this D -to-S shell intraband transition is investigated in quantum dots of varying size. Excitation of an electron-hole pair in the respective p shells leads to the formation of singlet and triplet spin configurations. Relaxation of the p -shell singlet is observed to occur on a time scale of a few picoseconds. Pumping of p -shell triplet transitions opens up two pathways with distinctly different scattering times. These processes are shown to be governed by the mixing of singlet and triplet states due to exchange interactions enabling simultaneous electron and hole spin flips. To isolate the relaxation channels, we align the spin of the residual electron by a magnetic field and employ laser pulses of defined helicity. This step provides ultrafast preparation of a fully inverted trion ground state of the quantum dot with near unity probability, enabling deterministic addition of a single photon to the probe pulse. Therefore our experiments represent a significant step towards using single quantum emitters with well-controled inversion to manipulate the photon statistics of ultrafast light pulses.

Shell-Dependent Photoluminescence Studies Provide Mechanistic Insights into the Off-Grey-On Transitions of Blinking Quantum Dots.

PubMed

Gao, Feng; Bajwa, Pooja; Nguyen, Anh; Heyes, Colin D

2017-03-28

The majority of quantum dot (QD) blinking studies have used a model of switching between two distinct fluorescence intensity levels, "on" and "off". However, a distinct intermediate intensity level has been identified in some recent reports, a so-called "grey" or "dim" state, which has brought this binary model into question. While this grey state has been proposed to result from the formation of a trion, it is still unclear under which conditions it is present in a QD. By performing shell-dependent blinking studies on CdSe QDs, we report that the populations of the grey state and the on state are strongly dependent on both the shell material and its thickness. We found that adding a ZnS shell did not result in a significant population of the grey state. Using ZnSe as the shell material resulted in a slightly higher population of the grey state, although it was still poorly resolved. However, adding a CdS shell resulted in the population of a grey state, which depended strongly on its thickness up to 5 ML. Interestingly, while the frequency of transitions to and from the grey state showed a very strong dependence on CdS shell thickness, the brightness of and the dwell time in the grey state did not. Moreover, we found that the grey state acts as an on-pathway intermediate state between on and off states, with the thickness of the shell determining the transition probability between them. We also identified two types of blinking behavior in QDs, one that showed long-lived but lower intensity on states and another that showed short-lived but brighter on states that also depended on the shell thickness. Intensity-resolved single QD fluorescence lifetime analysis was used to identify the relationship between the various exciton decay pathways and the resulting intensity levels. We used this data to propose a model in which multiple on, grey, and off states exist whose equilibrium populations vary with time that give rise to the various intensity levels of single QDs and which depends on shell composition and thickness.

Low pressure bottom-up synthesis of metal@oxide and oxide nanoparticles: control of structure and functional properties

NASA Astrophysics Data System (ADS)

D'Addato, Sergio; Chiara Spadaro, Maria

2018-03-01

Experimental activity on core@shell, metal@oxide, and oxide nanoparticles (NPs) grown with physical synthesis, and more specifically by low pressure gas aggregation sources (LPGAS) is reviewed, through a selection of examples encompassing some potential applications in nanotechnology. After an introduction to the applications of NPs, a brief description of the main characteristics of the growth process of clusters and NPs in LPGAS is given. Thereafter, some relevant case studies are reported: • Formation of native oxide shells around the metal cores in core@shell NPs. • Experimental efforts to obtain magnetic stabilization in magnetic core@shell NPs by controlling their structure and morphology. • Recent advancements in NP source design and new techniques of co-deposition, with relevant results in the realization of NPs with a greater variety of functionalities. • Recent results on reducible oxide NPs, with potentialities in nanocatalysis, energy storage, and other applications. Although this list is far from being exhaustive, the aim of the authors is to provide the reader a descriptive glimpse into the physics behind the growth and studies of low pressure gas-phase synthesized NPs, with their ever-growing potentialities for the rational design of new functional materials.

Facile Synthesis of Carbon Nanosphere/NiCo2O4 Core-shell Sub-microspheres for High Performance Supercapacitor

PubMed Central

Li, Delong; Gong, Youning; Zhang, Yupeng; Luo, Chengzhi; Li, Weiping; Fu, Qiang; Pan, Chunxu

2015-01-01

This paper introduced a process to prepare the carbon nanosphere (CNS)/NiCo2O4 core-shell sub-microspheres. That is: 1) CNSs were firstly prepared via a simple hydrothermal method; 2) a layer of NiCo2O4 precursor was coated on the CNS surface; 3) finally the composite was annealed at 350 °C for 2 hours in the air, and the CNS/NiCo2O4 core-shell sub-microspheres were obtained. This core-shell sub-microsphere was prepared with a simple, economical and environmental-friendly hydrothermal method, and was suitable for large-scale production, which expects a promising electrode candidate for high performance energy storage applications. Electrochemical experiments revealed that the composite exhibited remarkable electrochemical performances with high capacitance and desirable cycle life at high rates, such as: 1) the maximum specific capacitance was up to 1420 F/g at 1 A/g; 2) about 98.5% of the capacitance retained after 3000 charge-discharge cycles; 3) the capacitance retention was about 72% as the current density increase from 1 A/g to 10 A/g. PMID:26245982

Heat transfer models for predicting Salmonella enteritidis in shell eggs through supply chain distribution.

PubMed

Almonacid, S; Simpson, R; Teixeira, A

2007-11-01

Egg and egg preparations are important vehicles for Salmonella enteritidis infections. The influence of time-temperature becomes important when the presence of this organism is found in commercial shell eggs. A computer-aided mathematical model was validated to estimate surface and interior temperature of shell eggs under variable ambient and refrigerated storage temperature. A risk assessment of S. enteritidis based on the use of this model, coupled with S. enteritidis kinetics, has already been reported in a companion paper published earlier in JFS. The model considered the actual geometry and composition of shell eggs and was solved by numerical techniques (finite differences and finite elements). Parameters of interest such as local (h) and global (U) heat transfer coefficient, thermal conductivity, and apparent volumetric specific heat were estimated by an inverse procedure from experimental temperature measurement. In order to assess the error in predicting microbial population growth, theoretical and experimental temperatures were applied to a S. enteritidis growth model taken from the literature. Errors between values of microbial population growth calculated from model predicted compared with experimentally measured temperatures were satisfactorily low: 1.1% and 0.8% for the finite difference and finite element model, respectively.

Nickel/silicon core/shell nanosheet arrays as electrode materials for lithium ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, X.H., E-mail: drhuangxh@hotmail.com; Zhang, P.; Wu, J.B.

Highlights: • Ni nanosheet arrays is the core and Si layer is the shell. • Ni nanosheet arrays act as a three-dimensional current collector to support Si. • Ni nanosheet arrays can improve the conductivity and stability of the electrode. • Ni/Si nanosheet arrays exhibit excellent cyclic and rate performance. - Abstract: Ni/Si core/shell nanosheet arrays are proposed to enhance the electrochemical lithium-storage properties of silicon. The arrays are characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The arrays are micro-sized in height, which are constructed by interconnected Ni nanosheet as themore » core and Si coating layer as the shell. The electrochemical properties as anode materials of lithium ion batteries are investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. The arrays can achieve high reversible capacity, good cycle stability and high rate capability. It is believed that the enhanced electrochemical performance is attributed to the electrode structure, because the interconnected Ni nanosheet can act as a three-dimensional current collector, and it has the ability of improving the electrode conductivity, enlarging the electrochemical reaction interface, and suppressing the electrode pulverization.« less

A Scalable Strategy To Develop Advanced Anode for Sodium-Ion Batteries: Commercial Fe3O4-Derived Fe3O4@FeS with Superior Full-Cell Performance.

PubMed

Hou, Bao-Hua; Wang, Ying-Ying; Guo, Jin-Zhi; Zhang, Yu; Ning, Qiu-Li; Yang, Yang; Li, Wen-Hao; Zhang, Jing-Ping; Wang, Xin-Long; Wu, Xing-Long

2018-01-31

A novel core-shell Fe 3 O 4 @FeS composed of Fe 3 O 4 core and FeS shell with the morphology of regular octahedra has been prepared via a facile and scalable strategy via employing commercial Fe 3 O 4 as the precursor. When used as anode material for sodium-ion batteries (SIBs), the prepared Fe 3 O 4 @FeS combines the merits of FeS and Fe 3 O 4 with high Na-storage capacity and superior cycling stability, respectively. The optimized Fe 3 O 4 @FeS electrode shows ultralong cycle life and outstanding rate capability. For instance, it remains a capacity retention of 90.8% with a reversible capacity of 169 mAh g -1 after 750 cycles at 0.2 A g -1 and 151 mAh g -1 at a high current density of 2 A g -1 , which is about 7.5 times in comparison to the Na-storage capacity of commercial Fe 3 O 4 . More importantly, the prepared Fe 3 O 4 @FeS also exhibits excellent full-cell performance. The assembled Fe 3 O 4 @FeS//Na 3 V 2 (PO 4 ) 2 O 2 F sodium-ion full battery gives a reversible capacity of 157 mAh g -1 after 50 cycles at 0.5 A g -1 with a capacity retention of 92.3% and the Coulombic efficiency of around 100%, demonstrating its applicability for sodium-ion full batteries as a promising anode. Furthermore, it is also disclosed that such superior electrochemical properties can be attributed to the pseudocapacitive behavior of FeS shell as demonstrated by the kinetics studies as well as the core-shell structure. In view of the large-scale availability of commercial precursor and ease of preparation, this study provide a scalable strategy to develop advanced anode materials for SIBs.

Formation, characterization, and dynamics of onion-like carbon structures for electrical energy storage from nanodiamonds using reactive force fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ganesh, P.; Kent, P. R. C.; Mochalin, V.

We simulate the experimentally observed graphitization of nanodiamonds into multi-shell onion-like carbonnanostructures, also called carbon onions, at different temperatures, using reactive force fields. The simulations include long-range Coulomb and van der Waals interactions. Our results suggest that long-range interactions play a crucial role in the phase-stability and the graphitization process. Graphitization is both enthalpically and entropically driven and can hence be controlled with temperature. The outer layers of the nanodiamond have a lower kinetic barrier toward graphitization irrespective of the size of the nanodiamond and graphitize within a few-hundred picoseconds, with a large volume increase. The inner core of themore » nanodiamonds displays a large size-dependent kinetic barrier, and graphitizes much more slowly with abrupt jumps in the internal energy. It eventually graphitizes by releasing pressure and expands once the outer shells have graphitized. The degree of transformation at a particular temperature is thereby determined by a delicate balance between the thermal energy, long-range interactions, and the entropic/enthalpic free energy gained by graphitization. Upon full graphitization, a multi-shell carbonnanostructure appears, with a shell-shell spacing of about ~3.4 Å for all sizes. The shells are highly defective with predominantly five- and seven-membered rings to curve space. Larger nanodiamonds with a diameter of 4 nm can graphitize into spiral structures with a large (~29-atom carbon ring) pore opening on the outermost shell. Such a large one-way channel is most attractive for a controlled insertion of molecules/ions such as Li ions, water, or ionic liquids, for increased electrochemical capacitor or battery electrode applications.« less

Formation, characterization and dynamics of onion like carbon structures from nanodiamonds using reactive force-fields for electrical energy storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kent, Paul R

We simulate the experimentally observed graphitization of nanodiamonds into multi-shell onion-like carbon nanostructures, also called carbon onions, at different temperatures, using reactive force fields. The simulations include long-range Coulomb and van der Waals interactions. Our results suggest that long-range interactions play a crucial role in the phase-stability and the graphitization process. Graphitization is both enthalpically and entropically driven and can hence be controlled with temperature. The outer layers of the nanodiamond have a lower kinetic barrier toward graphitization irrespective of the size of the nanodiamond and graphitize within a few-hundred picoseconds, with a large volume increase. The inner core ofmore » the nanodiamonds displays a large size-dependent kinetic barrier, and graphitizes much more slowly with abrupt jumps in the internal energy. It eventually graphitizes by releasing pressure and expands once the outer shells have graphitized. The degree of transformation at a particular temperature is thereby determined by a delicate balance between the thermal energy, long-range interactions, and the entropic/enthalpic free energy gained by graphitization. Upon full graphitization, a multi-shell carbon nanostructure appears, with a shell-shell spacing of about {approx}3.4 {angstrom} for all sizes. The shells are highly defective with predominantly five- and seven-membered rings to curve space. Larger nanodiamonds with a diameter of 4 nm can graphitize into spiral structures with a large ({approx}29-atom carbon ring) pore opening on the outermost shell. Such a large one-way channel is most attractive for a controlled insertion of molecules/ions such as Li ions, water, or ionic liquids, for increased electrochemical capacitor or battery electrode applications.« less

Calcium hydroxide coating on highly reactive nanoscale zero-valent iron for in situ remediation application.

PubMed

Wei, Cai-Jie; Xie, Yue-Feng; Wang, Xiao-Mao; Li, Xiao-Yan

2018-05-23

Nano scale zero-valent iron (nZVI), a promising engineering technology for in situ remediation, has been greatly limited by quick self-corrosion and low mobility in porous media. Highly reactive nZVI particles produced from the borohydride reduction method were enclosed in a releasable Ca(OH) 2 layer by the chemical deposition method. The amount of Ca(OH) 2 coated on nZVI surface were well controlled by the precursor dosage. At moderate Ca(OH) 2 dosage (R Ca/TFe  = 0.25) condition, the increment of Fe 0 content for the obtained nZVI/Ca-0.25 sample was observed. The interfacial reactions between the iron oxide shell and the Ca(OH) 2 saturated environment were delicately elucidated by the X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) spectrum. And the coverage of Ca(OH) 2 shell on spherical nZVI surface was found more complete and uniform for the nZVI/Ca sample obtained from the moderate precursor dosage condition (R Ca/TFe  = 0.25). The Ca(OH) 2 shell before dissolution was demonstrated owning the anti-corrosion capability to slow down the oxidation of Fe 0 core in air, during ethanol storage and in aqueous environment. The mechanism of anti-corrosion capability for nZVI/Ca-0.25 particle was interestingly found to be attributed to the Ca(OH) 2 shell isolation and also be potentially due to the iron oxide shell phase transformation mediated by the outer Ca(OH) 2 shell. An improved trichloroethylene reduction performance was observed for nZVI/Ca-0.25 than bare nZVI. The mobility of nZVI/Ca particles in water-saturated porous media was moderately improved before shell dissolution. Copyright © 2018 Elsevier Ltd. All rights reserved.

High-temperature stability of the hydrate shell of a Na+ cation in a flat nanopore with hydrophobic walls

NASA Astrophysics Data System (ADS)

Shevkunov, S. V.

2017-11-01

The effect of elevated temperature has on the hydrate shell of a singly charged sodium cation inside a flat nanopore with smooth walls is studied using the Monte Carlo method. The free energy and the entropy of vapor molecule attachment are calculated by means of a bicanonical statistical ensemble using a detailed model of interactions. The nanopore has a stabilizing effect on the hydrate shell with respect to fluctuations and a destabilizing effect with respect to complete evaporation. At the boiling point of water, behavior is observed that is qualitatively similar to behavior at room temperature, but with a substantial shift in the vapor pressure and shell size.

Multishell Au/Ag/SiO 2 nanorods with tunable optical properties as single particle orientation and rotational tracking probes

DOE PAGES

Chen, Kuangcai; Lin, Chia -Cheng; Vela, Javier; ...

2015-04-07

In this study, three-layer core–shell plasmonic nanorods (Au/Ag/SiO 2–NRs), consisting of a gold nanorod core, a thin silver shell, and a thin silica layer, were synthesized and used as optical imaging probes under a differential interference contrast microscope for single particle orientation and rotational tracking. The localized surface plasmon resonance modes were enhanced upon the addition of the silver shell, and the anisotropic optical properties of gold nanorods were maintained. The silica coating enables surface functionalization with silane coupling agents and provides enhanced stability and biocompatibility. Taking advantage of the longitudinal LSPR enhancement, the orientation and rotational information of themore » hybrid nanorods on synthetic lipid bilayers and on live cell membranes were obtained with millisecond temporal resolution using a scientific complementary metal-oxide-semiconductor camera. The results demonstrate that the as-synthesized hybrid nanorods are promising imaging probes with improved sensitivity and good biocompatibility for single plasmonic particle tracking experiments in biological systems.« less

Merging single-shot XFEL diffraction data from inorganic nanoparticles: a new approach to size and orientation determination

DOE PAGES

Li, Xuanxuan; Spence, John C. H.; Hogue, Brenda G.; ...

2017-09-22

X-ray free-electron lasers (XFELs) provide new opportunities for structure determination of biomolecules, viruses and nanomaterials. With unprecedented peak brilliance and ultra-short pulse duration, XFELs can tolerate higher X-ray doses by exploiting the femtosecond-scale exposure time, and can thus go beyond the resolution limits achieved with conventional X-ray diffraction imaging techniques. Using XFELs, it is possible to collect scattering information from single particles at high resolution, however particle heterogeneity and unknown orientations complicate data merging in three-dimensional space. Using the Linac Coherent Light Source (LCLS), synthetic inorganic nanocrystals with a core–shell architecture were used as a model system for proof-of-principle coherentmore » diffractive single-particle imaging experiments. To deal with the heterogeneity of the core–shell particles, new computational methods have been developed to extract the particle size and orientation from the scattering data to assist data merging. The size distribution agrees with that obtained by electron microscopy and the merged data support a model with a core–shell architecture.« less

Merging single-shot XFEL diffraction data from inorganic nanoparticles: a new approach to size and orientation determination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xuanxuan; Spence, John C. H.; Hogue, Brenda G.

X-ray free-electron lasers (XFELs) provide new opportunities for structure determination of biomolecules, viruses and nanomaterials. With unprecedented peak brilliance and ultra-short pulse duration, XFELs can tolerate higher X-ray doses by exploiting the femtosecond-scale exposure time, and can thus go beyond the resolution limits achieved with conventional X-ray diffraction imaging techniques. Using XFELs, it is possible to collect scattering information from single particles at high resolution, however particle heterogeneity and unknown orientations complicate data merging in three-dimensional space. Using the Linac Coherent Light Source (LCLS), synthetic inorganic nanocrystals with a core–shell architecture were used as a model system for proof-of-principle coherentmore » diffractive single-particle imaging experiments. To deal with the heterogeneity of the core–shell particles, new computational methods have been developed to extract the particle size and orientation from the scattering data to assist data merging. The size distribution agrees with that obtained by electron microscopy and the merged data support a model with a core–shell architecture.« less

Single-fabrication-step Ge nanosphere/SiO2/SiGe heterostructures: a key enabler for realizing Ge MOS devices

NASA Astrophysics Data System (ADS)

Liao, P. H.; Peng, K. P.; Lin, H. C.; George, T.; Li, P. W.

2018-05-01

We report channel and strain engineering of self-organized, gate-stacking heterostructures comprising Ge-nanosphere gate/SiO2/SiGe-channels. An exquisitely-controlled dynamic balance between the concentrations of oxygen, Si, and Ge interstitials was effectively exploited to simultaneously create these heterostructures in a single oxidation step. Process-controlled tunability of the channel length (5–95 nm diameters for the Ge-nanospheres), gate oxide thickness (2.5–4.8 nm), as well as crystal orientation, chemical composition and strain engineering of the SiGe-channel was achieved. Single-crystalline (100) Si1‑x Ge x shells with Ge content as high as x = 0.85 and with a compressive strain of 3%, as well as (110) Si1‑x Ge x shells with Ge content of x = 0.35 and corresponding compressive strain of 1.5% were achieved. For each crystal orientation, our high Ge-content, highly-stressed SiGe shells feature a high degree of crystallinity and thus, provide a core ‘building block’ required for the fabrication of Ge-based MOS devices.

Single-fabrication-step Ge nanosphere/SiO2/SiGe heterostructures: a key enabler for realizing Ge MOS devices.

PubMed

Liao, P H; Peng, K P; Lin, H C; George, T; Li, P W

2018-05-18

We report channel and strain engineering of self-organized, gate-stacking heterostructures comprising Ge-nanosphere gate/SiO 2 /SiGe-channels. An exquisitely-controlled dynamic balance between the concentrations of oxygen, Si, and Ge interstitials was effectively exploited to simultaneously create these heterostructures in a single oxidation step. Process-controlled tunability of the channel length (5-95 nm diameters for the Ge-nanospheres), gate oxide thickness (2.5-4.8 nm), as well as crystal orientation, chemical composition and strain engineering of the SiGe-channel was achieved. Single-crystalline (100) Si 1-x Ge x shells with Ge content as high as x = 0.85 and with a compressive strain of 3%, as well as (110) Si 1-x Ge x shells with Ge content of x = 0.35 and corresponding compressive strain of 1.5% were achieved. For each crystal orientation, our high Ge-content, highly-stressed SiGe shells feature a high degree of crystallinity and thus, provide a core 'building block' required for the fabrication of Ge-based MOS devices.

In vivo magnetic resonance and fluorescence dual imaging of tumor sites by using dye-doped silica-coated iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Jang, Haeyun; Lee, Chaedong; Nam, Gi-Eun; Quan, Bo; Choi, Hyuck Jae; Yoo, Jung Sun; Piao, Yuanzhe

2016-02-01

The difficulty in delineating tumor is a major obstacle for better outcomes in cancer treatment of patients. The use of single-imaging modality is often limited by inadequate sensitivity and resolution. Here, we present the synthesis and the use of monodisperse iron oxide nanoparticles coated with fluorescent silica nano-shells for fluorescence and magnetic resonance dual imaging of tumor. The as-synthesized core-shell nanoparticles were designed to improve the accuracy of diagnosis via simultaneous tumor imaging with dual imaging modalities by a single injection of contrast agent. The iron oxide nanocrystals ( 11 nm) were coated with Rhodamine B isothiocyanate-doped silica shells via reverse microemulsion method. Then, the core-shell nanoparticles ( 54 nm) were analyzed to confirm their size distribution by transmission electron microscopy and dynamic laser scattering. Photoluminescence spectroscopy was used to characterize the fluorescent property of the dye-doped silica shell-coated nanoparticles. The cellular compatibility of the as-prepared nanoparticles was confirmed by a trypan blue dye exclusion assay and the potential as a dual-imaging contrast agent was verified by in vivo fluorescence and magnetic resonance imaging. The experimental results show that the uniform-sized core-shell nanoparticles are highly water dispersible and the cellular toxicity of the nanoparticles is negligible. In vivo fluorescence imaging demonstrates the capability of the developed nanoparticles to selectively target tumors by the enhanced permeability and retention effects and ex vivo tissue analysis was corroborated this. Through in vitro phantom test, the core/shell nanoparticles showed a T2 relaxation time comparable to Feridex® with smaller size, indicating that the as-made nanoparticles are suitable for imaging tumor. This new dual-modality-nanoparticle approach has promised for enabling more accurate tumor imaging.

Tailored Core Shell Cathode Powders for Solid Oxide Fuel Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swartz, Scott

2015-03-23

In this Phase I SBIR project, a “core-shell” composite cathode approach was evaluated for improving SOFC performance and reducing degradation of lanthanum strontium cobalt ferrite (LSCF) cathode materials, following previous successful demonstrations of infiltration approaches for achieving the same goals. The intent was to establish core-shell cathode powders that enabled high performance to be obtained with “drop-in” process capability for SOFC manufacturing (i.e., rather than adding an infiltration step to the SOFC manufacturing process). Milling, precipitation and hetero-coagulation methods were evaluated for making core-shell composite cathode powders comprised of coarse LSCF “core” particles and nanoscale “shell” particles of lanthanum strontiummore » manganite (LSM) or praseodymium strontium manganite (PSM). Precipitation and hetero-coagulation methods were successful for obtaining the targeted core-shell morphology, although perfect coverage of the LSCF core particles by the LSM and PSM particles was not obtained. Electrochemical characterization of core-shell cathode powders and conventional (baseline) cathode powders was performed via electrochemical impedance spectroscopy (EIS) half-cell measurements and single-cell SOFC testing. Reliable EIS testing methods were established, which enabled comparative area-specific resistance measurements to be obtained. A single-cell SOFC testing approach also was established that enabled cathode resistance to be separated from overall cell resistance, and for cathode degradation to be separated from overall cell degradation. The results of these EIS and SOFC tests conclusively determined that the core-shell cathode powders resulted in significant lowering of performance, compared to the baseline cathodes. Based on the results of this project, it was concluded that the core-shell cathode approach did not warrant further investigation.« less

A Shell-Shaped Carbon Architecture with High-Loading Capability for Lithium Sulfide Cathodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Sheng-Heng; Han, Pauline; Chang, Chi-Hao

We present that lithium sulfide (Li 2S) is considered a highly attractive cathode for establishing high-energy-density rechargeable batteries, especially due to its high charge-storage capacity and compatibility with lithium-metal-free anodes. Although various approaches have recently been pursued with Li 2S to obtain high performance, formidable challenges still remain with cell design (e.g., low Li 2S loading, insufficient Li 2S content, and an excess electrolyte) to realize high areal, gravimetric, and volumetric capacities. This study demonstrates a shell-shaped carbon architecture for holding pure Li 2S, offering innovation in cell-design parameters and gains in electrochemical characteristics. The Li 2S core–carbon shell electrodemore » encapsulates the redox products within the conductive shell so as to facilitate facile accessibility to electrons and ions. The fast redox-reaction kinetics enables the cells to attain the highest Li 2S loading of 8 mg cm -2 and the lowest electrolyte/Li 2S ratio of 9/1, which is the best cell-design specifications ever reported with Li 2S cathodes so far. Lastly, benefiting from the excellent cell-design criterion, the core–shell cathodes exhibit stable cyclability from slow to fast cycle rates and, for the first time, simultaneously achieve superior performance metrics with areal, gravimetric, and volumetric capacities.« less

A computer program for the geometrically nonlinear static and dynamic analysis of arbitrarily loaded shells of revolution, theory and users manual

NASA Technical Reports Server (NTRS)

Ball, R. E.

1972-01-01

A digital computer program known as SATANS (static and transient analysis, nonlinear, shells) for the geometrically nonlinear static and dynamic response of arbitrarily loaded shells of revolution is presented. Instructions for the preparation of the input data cards and other information necessary for the operation of the program are described in detail and two sample problems are included. The governing partial differential equations are based upon Sanders' nonlinear thin shell theory for the conditions of small strains and moderately small rotations. The governing equations are reduced to uncoupled sets of four linear, second order, partial differential equations in the meridional and time coordinates by expanding the dependent variables in a Fourier sine or cosine series in the circumferential coordinate and treating the nonlinear modal coupling terms as pseudo loads. The derivatives with respect to the meridional coordinate are approximated by central finite differences, and the displacement accelerations are approximated by the implicit Houbolt backward difference scheme with a constant time interval. The boundaries of the shell may be closed, free, fixed, or elastically restrained. The program is coded in the FORTRAN 4 language and is dimensioned to allow a maximum of 10 arbitrary Fourier harmonics and a maximum product of the total number of meridional stations and the total number of Fourier harmonics of 200. The program requires 155,000 bytes of core storage.

Yolk-Shelled C@Fe3 O4 Nanoboxes as Efficient Sulfur Hosts for High-Performance Lithium-Sulfur Batteries.

PubMed

He, Jiarui; Luo, Liu; Chen, Yuanfu; Manthiram, Arumugam

2017-09-01

Owing to the high theoretical specific capacity (1675 mA h g -1 ) and low cost, lithium-sulfur (Li-S) batteries offer advantages for next-generation energy storage. However, the polysulfide dissolution and low electronic conductivity of sulfur cathodes limit the practical application of Li-S batteries. To address such issues, well-designed yolk-shelled carbon@Fe 3 O 4 (YSC@Fe 3 O 4 ) nanoboxes as highly efficient sulfur hosts for Li-S batteries are reported here. With both physical entrapment by carbon shells and strong chemical interaction with Fe 3 O 4 cores, this unique architecture immobilizes the active material and inhibits diffusion of the polysulfide intermediates. Moreover, due to their high conductivity, the carbon shells and the polar Fe 3 O 4 cores facilitate fast electron/ion transport and promote continuous reactivation of the active material during the charge/discharge process, resulting in improved electrochemical utilization and reversibility. With these merits, the S/YSC@Fe 3 O 4 cathodes support high sulfur content (80 wt%) and loading (5.5 mg cm -2 ) and deliver high specific capacity, excellent rate capacity, and long cycling stability. This work provides a new perspective to design a carbon/metal-oxide-based yolk-shelled framework as a high sulfur-loading host for advanced Li-S batteries with superior electrochemical properties. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Shell-Shaped Carbon Architecture with High-Loading Capability for Lithium Sulfide Cathodes

DOE PAGES

Chung, Sheng-Heng; Han, Pauline; Chang, Chi-Hao; ...

2017-05-11

We present that lithium sulfide (Li 2S) is considered a highly attractive cathode for establishing high-energy-density rechargeable batteries, especially due to its high charge-storage capacity and compatibility with lithium-metal-free anodes. Although various approaches have recently been pursued with Li 2S to obtain high performance, formidable challenges still remain with cell design (e.g., low Li 2S loading, insufficient Li 2S content, and an excess electrolyte) to realize high areal, gravimetric, and volumetric capacities. This study demonstrates a shell-shaped carbon architecture for holding pure Li 2S, offering innovation in cell-design parameters and gains in electrochemical characteristics. The Li 2S core–carbon shell electrodemore » encapsulates the redox products within the conductive shell so as to facilitate facile accessibility to electrons and ions. The fast redox-reaction kinetics enables the cells to attain the highest Li 2S loading of 8 mg cm -2 and the lowest electrolyte/Li 2S ratio of 9/1, which is the best cell-design specifications ever reported with Li 2S cathodes so far. Lastly, benefiting from the excellent cell-design criterion, the core–shell cathodes exhibit stable cyclability from slow to fast cycle rates and, for the first time, simultaneously achieve superior performance metrics with areal, gravimetric, and volumetric capacities.« less

Novel Synthesis of Core-Shell Silica Nanoparticles for the Capture of Low Molecular Weight Proteins and Peptides.

PubMed

Hernandez-Leon, Sergio G; Sarabia-Sainz, Jose Andre-I; Montfort, Gabriela Ramos-Clamont; Guzman-Partida, Ana M; Robles-Burgueño, Maria Del Refugio; Vazquez-Moreno, Luz

2017-10-12

Silica nanoparticles were functionalized with immobilized molecular bait, Cibacron Blue, and a porous polymeric bis-acrylamide shell. These nanoparticles represent a new alternative to capture low molecular weight (LMW) proteins/peptides, that might be potential biomarkers. Functionalized core-shell silica nanoparticles (FCSNP) presented a size distribution of 243.9 ± 11.6 nm and an estimated surface charge of -38.1 ± 0.9 mV. The successful attachment of compounds at every stage of synthesis was evidenced by ATR-FTIR. The capture of model peptides was determined by mass spectrometry, indicating that only the peptide with a long sequence of hydrophobic amino acids (alpha zein 34-mer) interacted with the molecular bait. FCSNP excluded the high molecular weight protein (HMW), BSA, and captured LMW proteins (myoglobin and aprotinin), as evidenced by SDS-PAGE. Functionalization of nanoparticles with Cibacron Blue was crucial to capture these molecules. FCSNP were stable after twelve months of storage and maintained a capacity of 3.1-3.4 µg/mg.

Template-free synthesis of ordered ZnO@ZnS core-shell arrays for high performance supercapacitors.

PubMed

Yan, Hailong; Li, Tong; Lu, Yang; Cheng, Jinbing; Peng, Tao; Xu, Jinyou; Yang, Linying; Hua, Xiangqiang; Liu, Yunxin; Luo, Yongsong

2016-11-28

In this article, ordered ZnO@ZnS core-shell structures have been produced on a stainless mesh by a two-step approach without using a template. ZnO nanorods fabricated by a chemical vapor method are transferred into a 50 ml autoclave for a second stage ion-exchange reaction followed by heating at 120 °C for 4-16 h. The ZnO core is prepared as the conducting channel and ZnS as the active material. Such unique architecture exhibits remarkable electrochemical performance with high capacitance and desirable cycle life. When evaluating as the electrode for supercapacitors, the ZnO@ZnS core-shell structure delivers a high specific capacitance of 603.8 F g -1 at a current density of 2 A g -1 , with 9.4% capacitance loss after cycling 3000 times. The fabrication strategy presented here is simple and cost-effective, which can open new avenues for large-scale applications of the novel materials in energy storage.

Microwave-Assisted Synthesis of NiCo2O4 Double-Shelled Hollow Spheres for High-Performance Sodium Ion Batteries

NASA Astrophysics Data System (ADS)

Zhang, Xiong; Zhou, Yanping; Luo, Bin; Zhu, Huacheng; Chu, Wei; Huang, Kama

2018-03-01

The ternary transitional metal oxide NiCo2O4 is a promising anode material for sodium ion batteries due to its high theoretical capacity and superior electrical conductivity. However, its sodium storage capability is severely limited by the sluggish sodiation/desodiation reaction kinetics. Herein, NiCo2O4 double-shelled hollow spheres were synthesized via a microwave-assisted, fast solvothermal synthetic procedure in a mixture of isopropanol and glycerol, followed by annealing. Isopropanol played a vital role in the precipitation of nickel and cobalt, and the shrinkage of the glycerol quasi-emulsion under heat treatment was responsible for the formation of the double-shelled nanostructure. The as-synthesized product was tested as an anode material in a sodium ion battery, was found to exhibit a high reversible specific capacity of 511 mAh g-1 at 100 mA g-1, and deliver high capacity retention after 100 cycles. [Figure not available: see fulltext.

Interfacial Constructing Flexible V2O5@Polypyrrole Core-Shell Nanowire Membrane with Superior Supercapacitive Performance.

PubMed

Wang, Jian-Gan; Liu, Huanyan; Liu, Hongzhen; Hua, Wei; Shao, Minhua

2018-06-06

Flexible membrane consisting of ultralong V 2 O 5 @conducting polypyrrole (V 2 O 5 @PPy) core-shell nanowires is prepared by a facile in situ interfacial synthesis approach. The V 2 O 5 is for the first time demonstrated to show versatile function of reactive template to initiate the uniform and conformal polymerization of PPy nanocoating without the need for extra oxidants. The freestanding PPy-encapsulated V 2 O 5 nanowire membrane is of great benefit in achieving strong electrochemical harvest by increasing electrical conductivity, shortening ion/electron transport distance, and enlarging electrode/electrolyte contact area. When evaluated as binder- and additive-free supercapacitor electrodes, the V 2 O 5 @PPy core-shell hybrid delivers a significantly enhanced specific capacitance of 334 F g -1 along with superior rate capability and improved cycling stability. The present work would provide a simple yet powerful interfacial strategy for elaborate constructing V 2 O 5 /conducting polymers toward various energy-storage technologies.

Synthesis of green Fe3+/glucose/rGO electrode for supercapacitor application assisted by chemical exfoliation process from burning coconut shell

NASA Astrophysics Data System (ADS)

Putra, Gilang B. A.; Pradana, Herdy Y.; Soenaryo, Dimas E. T.; Baqiya, Malik A.; Darminto

2018-04-01

For the goal of large, environmental - friendly, renewable, and inexpensive energy storage, the development of supercapacitor electrodes is needed, by anchoring transition metal oxide (Fe3+ ion) as pseudo capacitor electrode material with reduced graphene oxide (rGO) from an old coconut shell as electrochemical double layer capacitor (EDLC). This porous electrode composite is prepared by sonication and chemical exfoliation assisted by acid. Synthesis of supercapacitor is also added by glucose, which acts as a spacer between layers of rGO to increase the capacitance, also as binder between the materials used. Combining Fe3+ with old coconut shell rGO give high specific capacitance of up to 99 F/g at a potential window of -1 V to 1 V. The Fe3+/glucose/rGO electrode has thickness of up to 57 nm (from PSA result) and give a uniform distribution from EDX mapping with disperse Fe domains and not bonding with rGO.

Graphene-Encapsulated Nanosheet-Assembled Zinc-Nickel-Cobalt Oxide Microspheres for Enhanced Lithium Storage.

PubMed

Zhang, Qiaobao; Chen, Huixin; Han, Xiang; Cai, Junjie; Yang, Yong; Liu, Meilin; Zhang, Kaili

2016-01-01

The appropriate combination of hierarchical transition-metal oxide (TMO) micro-/nanostructures constructed from porous nanobuilding blocks with graphene sheets (GNS) in a core/shell geometry is highly desirable for high-performance lithium-ion batteries (LIBs). A facile and scalable process for the fabrication of 3D hierarchical porous zinc-nickel-cobalt oxide (ZNCO) microspheres constructed from porous ultrathin nanosheets encapsulated by GNS to form a core/shell geometry is reported for improved electrochemical performance of the TMOs as an anode in LIBs. By virtue of their intriguing structural features, the produced ZNCO/GNS core/shell hybrids exhibit an outstanding reversible capacity of 1015 mA h g(-1) at 0.1 C after 50 cycles. Even at a high rate of 1 C, a stable capacity as high as 420 mA h g(-1) could be maintained after 900 cycles, which suggested their great potential as efficient electrodes for high-performance LIBs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Subwavelength core/shell cylindrical nanostructures for novel plasmonic and metamaterial devices

NASA Astrophysics Data System (ADS)

Kim, Kyoung-Ho; No, You-Shin

2017-12-01

In this review, we introduce novel plasmonic and metamaterial devices based on one-dimensional subwavelength nanostructures with cylindrical symmetry. Individual single devices with semiconductor/metal core/shell or dielectric/metal core/multi-shell structures experience strong light-matter interaction and yield unique optical properties with a variety of functions, e.g., invisibility cloaking, super-scattering/super-absorption, enhanced luminescence and nonlinear optical activities, and deep subwavelength-scale optical waveguiding. We describe the rational design of core/shell cylindrical nanostructures and the proper choice of appropriate constituent materials, which allow the efficient manipulation of electromagnetic waves and help to overcome the limitations of conventional homogeneous nanostructures. The recent developments of bottom-up synthesis combined with the top-down fabrication technologies for the practical applications and the experimental realizations of 1D subwavelength core/shell nanostructure devices are briefly discussed.

Formation of Multiple-Phase Catalysts for the Hydrogen Storage of Mg Nanoparticles by Adding Flowerlike NiS.

PubMed

Xie, Xiubo; Ma, Xiujuan; Liu, Peng; Shang, Jiaxiang; Li, Xingguo; Liu, Tong

2017-02-22

In order to enhance the hydrogen storage properties of Mg, flowerlike NiS particles have been successfully prepared by solvothermal reaction method, and are subsequently ball milled with Mg nanoparticles (NPs) to fabricate Mg-5 wt % NiS nanocomposite. The nanocomposite displays Mg/NiS core/shell structure. The NiS shell decomposes into Ni, MgS and Mg 2 Ni multiple-phases, decorating on the surface of the Mg NPs after the first hydrogen absorption and desorption cycle at 673 K. The Mg-MgS-Mg 2 Ni-Ni nanocomposite shows enhanced hydrogenation and dehydrogenation rates: it can quickly uptake 3.5 wt % H 2 within 10 min at 423 K and release 3.1 wt % H 2 within 10 min at 573 K. The apparent hydrogen absorption and desorption activation energies are decreased to 45.45 and 64.71 kJ mol -1 . The enhanced sorption kinetics of the nanocomposite is attributed to the synergistic catalytic effects of the in situ formed MgS, Ni and Mg 2 Ni multiple-phase catalysts during the hydrogenation/dehydrogenation process, the porthole effects for the volume expansion and microstrain of the phase transformation of Mg 2 Ni and Mg 2 NiH 4 and the reduced hydrogen diffusion distance caused by nanosized Mg. This novel method of in situ producing multiple-phase catalysts gives a new horizon for designing high performance hydrogen storage material.

High throughput chemical munitions treatment system

DOEpatents

Haroldsen, Brent L [Manteca, CA; Stofleth, Jerome H [Albuquerque, NM; Didlake, Jr., John E.; Wu, Benjamin C-P [San Ramon, CA

2011-11-01

A new High-Throughput Explosive Destruction System is disclosed. The new system is comprised of two side-by-side detonation containment vessels each comprising first and second halves that feed into a single agent treatment vessel. Both detonation containment vessels further comprise a surrounding ventilation facility. Moreover, the detonation containment vessels are designed to separate into two half-shells, wherein one shell can be moved axially away from the fixed, second half for ease of access and loading. The vessels are closed by means of a surrounding, clam-shell type locking seal mechanisms.

Ocean acidification alters the material properties of Mytilus edulis shells.

PubMed

Fitzer, Susan C; Zhu, Wenzhong; Tanner, K Elizabeth; Phoenix, Vernon R; Kamenos, Nicholas A; Cusack, Maggie

2015-02-06

Ocean acidification (OA) and the resultant changing carbonate saturation states is threatening the formation of calcium carbonate shells and exoskeletons of marine organisms. The production of biominerals in such organisms relies on the availability of carbonate and the ability of the organism to biomineralize in changing environments. To understand how biomineralizers will respond to OA the common blue mussel, Mytilus edulis, was cultured at projected levels of pCO2 (380, 550, 750, 1000 µatm) and increased temperatures (ambient, ambient plus 2°C). Nanoindentation (a single mussel shell) and microhardness testing were used to assess the material properties of the shells. Young's modulus (E), hardness (H) and toughness (KIC) were measured in mussel shells grown in multiple stressor conditions. OA caused mussels to produce shell calcite that is stiffer (higher modulus of elasticity) and harder than shells grown in control conditions. The outer shell (calcite) is more brittle in OA conditions while the inner shell (aragonite) is softer and less stiff in shells grown under OA conditions. Combining increasing ocean pCO2 and temperatures as projected for future global ocean appears to reduce the impact of increasing pCO2 on the material properties of the mussel shell. OA may cause changes in shell material properties that could prove problematic under predation scenarios for the mussels; however, this may be partially mitigated by increasing temperature. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Probing the Single-Particle Character of Rotational States in F 19 Using a Short-Lived Isomeric Beam

NASA Astrophysics Data System (ADS)

Santiago-Gonzalez, D.; Auranen, K.; Avila, M. L.; Ayangeakaa, A. D.; Back, B. B.; Bottoni, S.; Carpenter, M. P.; Chen, J.; Deibel, C. M.; Hood, A. A.; Hoffman, C. R.; Janssens, R. V. F.; Jiang, C. L.; Kay, B. P.; Kuvin, S. A.; Lauer, A.; Schiffer, J. P.; Sethi, J.; Talwar, R.; Wiedenhöver, I.; Winkelbauer, J.; Zhu, S.

2018-03-01

A beam containing a substantial component of both the Jπ=5+ , T1 /2=162 ns isomeric state of F 18 and its 1+, 109.77-min ground state is utilized to study members of the ground-state rotational band in F 19 through the neutron transfer reaction (d ,p ) in inverse kinematics. The resulting spectroscopic strengths confirm the single-particle nature of the 13 /2+ band-terminating state. The agreement between shell-model calculations using an interaction constructed within the s d shell, and our experimental results reinforces the idea of a single-particle-collective duality in the descriptions of the structure of atomic nuclei.

Computer-Aided Thermohydraulic Design of TEMA Type E Shell and Tube Heat Exchangers for Use in Low Pressure, Liquid-to-Liquid, Single Phase Applications.

DTIC Science & Technology

1985-04-01

and Standards .. ... ....... ....... 9 A. General . ... .. .. ... ..... .. .. ... 9 B. ASME Boiler and Pressure Vessel Code .. .. ......9 C. Foreign...several different sources. B. American Society of Mechanial Engineers (ASME) Boiler and Pressure Vessel Code A shell and tube heat exchanger is indeed a

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Kuangcai; Lin, Chia -Cheng; Vela, Javier

In this study, three-layer core–shell plasmonic nanorods (Au/Ag/SiO 2–NRs), consisting of a gold nanorod core, a thin silver shell, and a thin silica layer, were synthesized and used as optical imaging probes under a differential interference contrast microscope for single particle orientation and rotational tracking. The localized surface plasmon resonance modes were enhanced upon the addition of the silver shell, and the anisotropic optical properties of gold nanorods were maintained. The silica coating enables surface functionalization with silane coupling agents and provides enhanced stability and biocompatibility. Taking advantage of the longitudinal LSPR enhancement, the orientation and rotational information of themore » hybrid nanorods on synthetic lipid bilayers and on live cell membranes were obtained with millisecond temporal resolution using a scientific complementary metal-oxide-semiconductor camera. The results demonstrate that the as-synthesized hybrid nanorods are promising imaging probes with improved sensitivity and good biocompatibility for single plasmonic particle tracking experiments in biological systems.« less

Fully localized post-buckling states of cylindrical shells under axial compression

NASA Astrophysics Data System (ADS)

Kreilos, Tobias; Schneider, Tobias M.

2017-09-01

We compute nonlinear force equilibrium solutions for a clamped thin cylindrical shell under axial compression. The equilibrium solutions are dynamically unstable and located on the stability boundary of the unbuckled state. A fully localized single dimple deformation is identified as the edge state-the attractor for the dynamics restricted to the stability boundary. Under variation of the axial load, the single dimple undergoes homoclinic snaking in the azimuthal direction, creating states with multiple dimples arranged around the central circumference. Once the circumference is completely filled with a ring of dimples, snaking in the axial direction leads to further growth of the dimple pattern. These fully nonlinear solutions embedded in the stability boundary of the unbuckled state constitute critical shape deformations. The solutions may thus be a step towards explaining when the buckling and subsequent collapse of an axially loaded cylinder shell is triggered.

X-ray absorption spectroscopy of aluminum z-pinch plasma with tungsten backlighter planar wire array source.

PubMed

Osborne, G C; Kantsyrev, V L; Safronova, A S; Esaulov, A A; Weller, M E; Shrestha, I; Shlyaptseva, V V; Ouart, N D

2012-10-01

Absorption features from K-shell aluminum z-pinch plasmas have recently been studied on Zebra, the 1.7 MA pulse power generator at the Nevada Terawatt Facility. In particular, tungsten plasma has been used as a semi-backlighter source in the generation of aluminum K-shell absorption spectra by placing a single Al wire at or near the end of a single planar W array. All spectroscopic experimental results were recorded using a time-integrated, spatially resolved convex potassium hydrogen phthalate (KAP) crystal spectrometer. Other diagnostics used to study these plasmas included x-ray detectors, optical imaging, laser shadowgraphy, and time-gated and time-integrated x-ray pinhole imagers. Through comparisons with previous publications, Al K-shell absorption lines are shown to be from much lower electron temperature (∼10-40 eV) plasmas than emission spectra (∼350-500 eV).

Development and Deployment of the Extended Reach Sluicing System (ERSS) for Retrieval of Hanford Single Shell Tank Waste. Draft

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauer, Roger E.; Figley, Reed R.; Innes, A. G.

2013-11-11

A history of the evolution and the design development of Extended Reach Sluicer System (ERSS) is presented. Several challenges are described that had to be overcome to create a machine that went beyond the capabilities of prior generation sluicers to mobilize waste in Single Shell Tanks for pumping into Double Shell Tank receiver tanks. Off-the-shelf technology and traditional hydraulic fluid power systems were combined with the custom-engineered components to create the additional functionality of the ERSS, while still enabling it to fit within very tight entry envelope into the SST. Problems and challenges inevitably were encountered and overcome in waysmore » that enhance the state of the art of fluid power applications in such constrained environments. Future enhancements to the ERSS design are explored for retrieval of tanks with different dimensions and internal obstacles.« less

Mapping carrier diffusion in single silicon core-shell nanowires with ultrafast optical microscopy.

PubMed

Seo, M A; Yoo, J; Dayeh, S A; Picraux, S T; Taylor, A J; Prasankumar, R P

2012-12-12

Recent success in the fabrication of axial and radial core-shell heterostructures, composed of one or more layers with different properties, on semiconductor nanowires (NWs) has enabled greater control of NW-based device operation for various applications. (1-3) However, further progress toward significant performance enhancements in a given application is hindered by the limited knowledge of carrier dynamics in these structures. In particular, the strong influence of interfaces between different layers in NWs on transport makes it especially important to understand carrier dynamics in these quasi-one-dimensional systems. Here, we use ultrafast optical microscopy (4) to directly examine carrier relaxation and diffusion in single silicon core-only and Si/SiO(2) core-shell NWs with high temporal and spatial resolution in a noncontact manner. This enables us to reveal strong coherent phonon oscillations and experimentally map electron and hole diffusion currents in individual semiconductor NWs for the first time.

Gaps in nuclear spectra as traces of seniority changes in systems of both neutrons and protons

NASA Astrophysics Data System (ADS)

Zamick, Larry

2016-03-01

There has been a great deal of attention given to the low-lying energy spectrum in a nucleus because of the abundance of experimental data. Likewise, perhaps to a lesser extent but still significant, the high end for a given configuration has been examined. Here, using single j shell calculations as a guide, we examine the middle part of the spectrum resulting from single j shell calculations. Seniority arguments are used to partially explain the midshell behaviors even though in general seniority is not a good quantum number for mixed systems of neutrons and protons.

Single-Enzyme Nanoparticles Armored by a Nanometer-Scale Organic/Inorganic Network

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jungbae; Grate, Jay W.

2003-09-01

We have developed armored single-enzyme nanoparticles (SENs), which dramatically stabilize a protease (a-chymotrypsin, CT) by surrounding each enzyme molecule with a porous composite organic/inorganic shell of less than a few nanometers thick. The armored enzymes show no decrease in CT activity at 30C for four days while free CT activity is rapidly reduced by orders of magnitude. The armored shell around CT is sufficiently thin and porous that it does not place any serious mass-transfer limitation on substrates. This unique approach will have a great impact in using enzymes in various fields.

A facile single-step synthesis of ternary multicore magneto-plasmonic nanoparticles.

PubMed

Benelmekki, Maria; Bohra, Murtaza; Kim, Jeong-Hwan; Diaz, Rosa E; Vernieres, Jerome; Grammatikopoulos, Panagiotis; Sowwan, Mukhles

2014-04-07

We report a facile single-step synthesis of ternary hybrid nanoparticles (NPs) composed of multiple dumbbell-like iron-silver (FeAg) cores encapsulated by a silicon (Si) shell using a versatile co-sputter gas-condensation technique. In comparison to previously reported binary magneto-plasmonic NPs, the advantage conferred by a Si shell is to bind the multiple magneto-plasmonic (FeAg) cores together and prevent them from aggregation at the same time. Further, we demonstrate that the size of the NPs and number of cores in each NP can be modulated over a wide range by tuning the experimental parameters.

21 CFR 118.6 - Egg testing for Salmonella Enteritidis (SE).

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Egg testing for Salmonella Enteritidis (SE). 118.6... (CONTINUED) FOOD FOR HUMAN CONSUMPTION PRODUCTION, STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.6 Egg... age required by § 118.4(a) is positive, you must divert eggs to treatment (defined in § 118.3) for the...

Effects of alfalfa silage storage structure and roasting corn on ruminal digestion and microbial CP synthesis in lactating dairy cows

USDA-ARS?s Scientific Manuscript database

The objective of this experiment was to determine the effects of unroasted ground shelled corn (GSC) or roasted GSC (RGSC), when fed with alfalfa, ensiled in bag, bunker, or O2-limiting tower silos on ruminal digestion and microbial protein synthesis in lactating dairy cows. The roasted corn was hea...

State-of-the-Art Applicability of Conventional Densification Techniques to Increase Disposal Area Storage Capacity

DTIC Science & Technology

1977-04-01

Dipper dredge and silt. Approaches dry density incoarser material. Clam shell or orange peel. bucket d-redge SEndless chain bucket dredge Cutterhead...stage the big disk wheel is pulled by a tractor making ditches about 0.5 to 0.6 m deep and 10 m apart. When the first layer of mud has been

High pressure storage vessel

DOEpatents

Liu, Qiang

2013-08-27

Disclosed herein is a composite pressure vessel with a liner having a polar boss and a blind boss a shell is formed around the liner via one or more filament wrappings continuously disposed around at least a substantial portion of the liner assembly combined the liner and filament wrapping have a support profile. To reduce susceptible to rupture a locally disposed filament fiber is added.

Drilling side holes from a borehole

NASA Technical Reports Server (NTRS)

Collins, E. R., Jr.

1980-01-01

Machine takes long horizontal stratum samples from confines of 21 cm bore hole. Stacked interlocking half cylindrical shells mate to form rigid thrust tube. Drive shaft and core storage device is flexible and retractable. Entire machine fits in 10 meter length of steel tube. Machine could drill drainage or ventilation holes in coal mines, or provide important information for geological, oil, and geothermal surveys.

77 FR 5839 - Notice of Intent To Repatriate a Cultural Item: University of Denver Department of Anthropology...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-06

... that a cultural item meets the definition of sacred object and repatriation to the Indian tribes stated... sacred object under 25 U.S.C. 3001. This notice is published as part of the National Park Service's... storage of sacred items, shell money, beads and other treasured items. Ceremonial baskets were sometimes...

75 FR 11169 - AES Sparrows Point LNG, LLC; Mid-Atlantic Express, LLC; Notice of Availability of the Revised...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... LNG storage tanks; A closed-loop shell and tube heat exchanger vaporization system; Various ancillary..., there are three methods you can use to submit your comments to the Commission. In all instances please... encourages electronic filing of comments and has dedicated eFiling expert staff available to assist you at...

21 CFR 118.6 - Egg testing for Salmonella Enteritidis (SE).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Egg testing for Salmonella Enteritidis (SE). 118.6... (CONTINUED) FOOD FOR HUMAN CONSUMPTION PRODUCTION, STORAGE, AND TRANSPORTATION OF SHELL EGGS § 118.6 Egg... age required by § 118.4(a) is positive, you must divert eggs to treatment (defined in § 118.3) for the...

Refined hierarchical kinematics quasi-3D Ritz models for free vibration analysis of doubly curved FGM shells and sandwich shells with FGM core

NASA Astrophysics Data System (ADS)

Fazzolari, Fiorenzo A.; Carrera, Erasmo

2014-02-01

In this paper, the Ritz minimum energy method, based on the use of the Principle of Virtual Displacements (PVD), is combined with refined Equivalent Single Layer (ESL) and Zig Zag (ZZ) shell models hierarchically generated by exploiting the use of Carrera's Unified Formulation (CUF), in order to engender the Hierarchical Trigonometric Ritz Formulation (HTRF). The HTRF is then employed to carry out the free vibration analysis of doubly curved shallow and deep functionally graded material (FGM) shells. The PVD is further used in conjunction with the Gauss theorem to derive the governing differential equations and related natural boundary conditions. Donnell-Mushtari's shallow shell-type equations are given as a particular case. Doubly curved FGM shells and doubly curved sandwich shells made up of isotropic face sheets and FGM core are investigated. The proposed shell models are widely assessed by comparison with the literature results. Two benchmarks are provided and the effects of significant parameters such as stacking sequence, boundary conditions, length-to-thickness ratio, radius-to-length ratio and volume fraction index on the circular frequency parameters and modal displacements are discussed.

Core-shell TiO2@ZnO nanorods for efficient ultraviolet photodetection.

PubMed

Panigrahi, Shrabani; Basak, Durga

2011-05-01

Core-shell TiO(2)@ZnO nanorods (NRs) have been fabricated by a simple two step method: growth of ZnO NRs' array by an aqueous chemical technique and then coating of the NRs with a solution of titanium isopropoxide [Ti(OC(3)H(7))(4)] followed by a heating step to form the shell. The core-shell nanocomposites are composed of single-crystalline ZnO NRs, coated with a thin TiO(2) shell layer obtained by varying the number of coatings (one, three and five times). The ultraviolet (UV) emission intensity of the nanocomposite is largely quenched due to an efficient electron-hole separation reducing the band-to-band recombinations. The UV photoconductivity of the core-shell structure with three times TiO(2) coating has been largely enhanced due to photoelectron transfer between the core and the shell. The UV photosensitivity of the nanocomposite becomes four times larger while the photocurrent decay during steady UV illumination has been decreased almost by 7 times compared to the as-grown ZnO NRs indicating high efficiency of these core-shell structures as UV sensors. © The Royal Society of Chemistry 2011

Photoelectrodes based on 2D opals assembled from Cu-delafossite double-shelled microspheres for an enhanced photoelectrochemical response.

PubMed

Oh, Yunjung; Yang, Wooseok; Tan, Jeiwan; Lee, Hyungsoo; Park, Jaemin; Moon, Jooho

2018-02-22

Although a unique light-harvesting property was recently demonstrated in a photocathode based on 2-dimensional (2D) opals of CuFeO 2 -shelled SiO 2 microspheres, the performance of a monolayer of ultra-thin CuFeO 2 -shelled microspheres is limited by ineffective charge separation. Herein, we propose an innovative design rule, in which an inner CuFeO 2 /outer CuAlO 2 double-shelled heterojunction is formed on each partially etched microsphere to obtain a hexagonally assembled 2D opal photoelectrode. Our Cu-delafossite double-shelled photocathode shows a dramatically improved charge separation capability, with a 9-fold increase in the photocurrent compared to that of the single-shelled counterpart. Electrochemical impedance spectroscopy clearly confirms the reduced charge transport/transfer resistance associated with the Cu-delafossite double-shelled photocathode, while surface photovoltage spectra reveal enhanced polarization of the photogenerated carrier, indicating improved charge separation capability with the aid of the heterojunction. Our finding sheds light on the importance of heterojunction interfaces in achieving optimal charge separation in opal architectures as well as the inner-shell/electrolyte interface to expedite charge separation/transport.

Method for forming a bladder for fluid storage vessels

DOEpatents

Mitlitsky, Fred; Myers, Blake; Magnotta, Frank

2000-01-01

A lightweight, low permeability liner for graphite epoxy composite compressed gas storage vessels. The liner is composed of polymers that may or may not be coated with a thin layer of a low permeability material, such as silver, gold, or aluminum, deposited on a thin polymeric layer or substrate which is formed into a closed bladder using torispherical or near torispherical end caps, with or without bosses therein, about which a high strength to weight material, such as graphite epoxy composite shell, is formed to withstand the storage pressure forces. The polymeric substrate may be laminated on one or both sides with additional layers of polymeric film. The liner may be formed to a desired configuration using a dissolvable mandrel or by inflation techniques and the edges of the film seamed by heat sealing. The liner may be utilized in most any type of gas storage system, and is particularly applicable for hydrogen, gas mixtures, and oxygen used for vehicles, fuel cells or regenerative fuel cell applications, high altitude solar powered aircraft, hybrid energy storage/propulsion systems, and lunar/Mars space applications, and other applications requiring high cycle life.

New latent heat storage system with nanoparticles for thermal management of electric vehicles

NASA Astrophysics Data System (ADS)

Javani, N.; Dincer, I.; Naterer, G. F.

2014-12-01

In this paper, a new passive thermal management system for electric vehicles is developed. A latent heat thermal energy storage with nanoparticles is designed and optimized. A genetic algorithm method is employed to minimize the length of the heat exchanger tubes. The results show that even the optimum length of a shell and tube heat exchanger becomes too large to be employed in a vehicle. This is mainly due to the very low thermal conductivity of phase change material (PCM) which fills the shell side of the heat exchanger. A carbon nanotube (CNT) and PCM mixture is then studied where the probability of nanotubes in a series configuration is defined as a deterministic design parameter. Various heat transfer rates, ranging from 300 W to 600 W, are utilized to optimize battery cooling options in the heat exchanger. The optimization results show that smaller tube diameters minimize the heat exchanger length. Furthermore, finned tubes lead to a higher heat exchanger length due to more heat transfer resistance. By increasing the CNT concentration, the optimum length of the heat exchanger decreases and makes the improved thermal management system a more efficient and competitive with air and liquid thermal management systems.

Incorporation of T4 bacteriophage in electrospun fibres.

PubMed

Korehei, R; Kadla, J

2013-05-01

Antibacterial food packaging materials, such as bacteriophage-activated electrospun fibrous mats, may address concerns triggered by waves of bacterial food contamination. To address this, we investigated several efficient methods for incorporating T4 bacteriophage into electrospun fibrous mats. The incorporation of T4 bacteriophage using simple suspension electrospinning led to more than five orders of magnitude decrease in bacteriophage activity. To better maintain bacteriophage viability, emulsion electrospinning was developed where the T4 bacteriophage was pre-encapsulated in an alginate reservoir via an emulsification process and subsequently electrospun into fibres. This resulted in an increase in bacteriophage viability, but there was still two orders of magnitude drop in activity. Using a coaxial electrospinning process, full bacteriophage activity could be maintained. In this process, a core/shell fibre structure was formed with the T4 bacteriophage being directly incorporated into the fibre core. The core/shell fibre encapsulated bacteriophage exhibited full bacteriophage viability after storing for several weeks at +4°C. Coaxial electrospinning was shown to be capable of encapsulating bacteriophages with high loading capacity, high viability and long storage time. These results are significant in the context of controlling and preventing bacterial infections in perishable foods during storage. © 2013 The Society for Applied Microbiology.

Annular Air Leaks in a liquid hydrogen storage tank

NASA Astrophysics Data System (ADS)

Krenn, AG; Youngquist, RC; Starr, SO

2017-12-01

Large liquid hydrogen (LH2) storage tanks are vital infrastructure for NASA, the DOD, and industrial users. Over time, air may leak into the evacuated, perlite filled annular region of these tanks. Once inside, the extremely low temperatures will cause most of the air to freeze. If a significant mass of air is allowed to accumulate, severe damage can result from nominal draining operations. Collection of liquid air on the outer shell may chill it below its ductility range, resulting in fracture. Testing and analysis to quantify the thermal conductivity of perlite that has nitrogen frozen into its interstitial spaces and to determine the void fraction of frozen nitrogen within a perlite/frozen nitrogen mixture is presented. General equations to evaluate methods for removing frozen air, while avoiding fracture, are developed. A hypothetical leak is imposed on an existing tank geometry and a full analysis of that leak is detailed. This analysis includes a thermal model of the tank and a time-to-failure calculation. Approaches to safely remove the frozen air are analyzed, leading to the conclusion that the most feasible approach is to allow the frozen air to melt and to use a water stream to prevent the outer shell from chilling.

Preparation of PPy-Coated MnO2 Hybrid Micromaterials and Their Improved Cyclic Performance as Anode for Lithium-Ion Batteries

NASA Astrophysics Data System (ADS)

Feng, Lili; Zhang, Yinyin; Wang, Rui; Zhang, Yanli; Bai, Wei; Ji, Siping; Xuan, Zhewen; Yang, Jianhua; Zheng, Ziguang; Guan, Hongjin

2017-09-01

MnO2@PPy core-shell micromaterials are prepared by chemical polymerization of pyrrole on the MnO2 surface. The polypyrrole (PPy) is formed as a homogeneous organic shell on the MnO2 surface. The thickness of PPy shell can be adjusted by the usage of pyrrole. The analysis of SEM, FT-IR, X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), and XRD are used to confirm the formation of PPy shell. Galvanostatic cell cycling and electrochemical impedance spectroscopy (EIS) are used to evaluate the electrochemical performance as anode for lithium-ion batteries. The results show that after formation of MnO2@PPy core-shell micromaterials, the cyclic performance as anode for lithium-ion batteries is improved. Fifty microliters of PPy-coated caddice-clew-like MnO2 has the best cyclic performances as has 620 mAh g-1 discharge specific capacities after 300 cycles. As a comparison, the discharge specific capacity of bare MnO2 materials falls to below 200 mAh g-1 after 10 cycles. The improved lithium-storage cyclic stability of the MnO2@PPy samples attributes to the core-shell hybrid structure which can buffer the structural expansion and contraction of MnO2 caused by the repeated embedding and disengagement of Li ions and can prevent the pulverization of MnO2. This experiment provides an effective way to mitigate the problem of capacity fading of the transition metal oxide materials as anode materials for (lithium-ion batteries) LIBs.

Preparation of PPy-Coated MnO2 Hybrid Micromaterials and Their Improved Cyclic Performance as Anode for Lithium-Ion Batteries.

PubMed

Feng, Lili; Zhang, Yinyin; Wang, Rui; Zhang, Yanli; Bai, Wei; Ji, Siping; Xuan, Zhewen; Yang, Jianhua; Zheng, Ziguang; Guan, Hongjin

2017-09-02

MnO 2 @PPy core-shell micromaterials are prepared by chemical polymerization of pyrrole on the MnO 2 surface. The polypyrrole (PPy) is formed as a homogeneous organic shell on the MnO 2 surface. The thickness of PPy shell can be adjusted by the usage of pyrrole. The analysis of SEM, FT-IR, X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), and XRD are used to confirm the formation of PPy shell. Galvanostatic cell cycling and electrochemical impedance spectroscopy (EIS) are used to evaluate the electrochemical performance as anode for lithium-ion batteries. The results show that after formation of MnO 2 @PPy core-shell micromaterials, the cyclic performance as anode for lithium-ion batteries is improved. Fifty microliters of PPy-coated caddice-clew-like MnO 2 has the best cyclic performances as has 620 mAh g -1 discharge specific capacities after 300 cycles. As a comparison, the discharge specific capacity of bare MnO 2 materials falls to below 200 mAh g -1 after 10 cycles. The improved lithium-storage cyclic stability of the MnO 2 @PPy samples attributes to the core-shell hybrid structure which can buffer the structural expansion and contraction of MnO 2 caused by the repeated embedding and disengagement of Li ions and can prevent the pulverization of MnO 2 . This experiment provides an effective way to mitigate the problem of capacity fading of the transition metal oxide materials as anode materials for (lithium-ion batteries) LIBs.

Development of magnetic luminescent core/shell nanocomplex particles with fluorescence using Rhodamine 6G

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Hee Uk; Song, Yoon Seok; Park, Chulhwan

2012-12-15

Graphical abstract: Display Omitted Highlights: ► A simple method was developed to synthesize Co-B/SiO{sub 2}/dye/SiO{sub 2} composite particles. ► The magnetic particle shows that highly luminescent and core/shell particles are formed. ► Such core/shell particles can be easily suspended in water. ► The magnetic particles could detect fluorescence for the application of biosensor. -- Abstract: A simple and reproducible method was developed to synthesize a novel class of Co-B/SiO{sub 2}/dye/SiO{sub 2} composite core/shell particles. Using a single cobalt core, Rhodamine 6G of organic dye molecules was entrapped in a silica shell, resulting in core/shell particles of ∼200 nm diameter. Analysesmore » using a variety of techniques such as transmission electron microscopy, X-ray photoelectron spectroscopy, vibration sample magnetometry, confocal laser scanning microscopy, and fluorescence intensity demonstrated that dye molecules were trapped inside the core/shell particles. A photoluminescence investigation showed that highly luminescent and photostable core/shell particles were formed. Such core/shell particles can be easily suspended in water. The synthesized magnetic particles could be used to detect fluorescence on glass substrate arrays for bioassay and biosensor applications.« less

Core–Shell Nanoparticle Coating as an Interfacial Layer for Dendrite-Free Lithium Metal Anodes

DOE PAGES

Liu, Wei; Li, Weiyang; Zhuo, Denys; ...

2017-02-08

Lithium metal based batteries represent a major challenge and opportunity in enabling a variety of devices requiring high-energy-density storage. However, dendritic lithium growth has limited the practical application of lithium metal anodes. Here we report a nanoporous, flexible and electrochemically stable coating of silica@poly(methyl methacrylate) (SiO 2@PMMA) core–shell nanospheres as an interfacial layer on lithium metal anode. This interfacial layer is capable of inhibiting Li dendrite growth while sustaining ionic flux through it, which is attributed to the nanoscaled pores formed among the nanospheres. Lastly, enhanced Coulombic efficiencies during lithium charge/discharge cycles have been achieved at various current densities andmore » areal capacities.« less

Core–Shell Nanoparticle Coating as an Interfacial Layer for Dendrite-Free Lithium Metal Anodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Wei; Li, Weiyang; Zhuo, Denys

Lithium metal based batteries represent a major challenge and opportunity in enabling a variety of devices requiring high-energy-density storage. However, dendritic lithium growth has limited the practical application of lithium metal anodes. Here we report a nanoporous, flexible and electrochemically stable coating of silica@poly(methyl methacrylate) (SiO 2@PMMA) core–shell nanospheres as an interfacial layer on lithium metal anode. This interfacial layer is capable of inhibiting Li dendrite growth while sustaining ionic flux through it, which is attributed to the nanoscaled pores formed among the nanospheres. Lastly, enhanced Coulombic efficiencies during lithium charge/discharge cycles have been achieved at various current densities andmore » areal capacities.« less

Finite element dynamic analysis on CDC STAR-100 computer

NASA Technical Reports Server (NTRS)

Noor, A. K.; Lambiotte, J. J., Jr.

1978-01-01

Computational algorithms are presented for the finite element dynamic analysis of structures on the CDC STAR-100 computer. The spatial behavior is described using higher-order finite elements. The temporal behavior is approximated by using either the central difference explicit scheme or Newmark's implicit scheme. In each case the analysis is broken up into a number of basic macro-operations. Discussion is focused on the organization of the computation and the mode of storage of different arrays to take advantage of the STAR pipeline capability. The potential of the proposed algorithms is discussed and CPU times are given for performing the different macro-operations for a shell modeled by higher order composite shallow shell elements having 80 degrees of freedom.

N-doped amorphous carbon coated Fe3O4/SnO2 coaxial nanofibers as a binder-free self-supported electrode for lithium ion batteries.

PubMed

Xie, Wenhe; Li, Suyuan; Wang, Suiyan; Xue, Song; Liu, Zhengjiao; Jiang, Xinyu; He, Deyan

2014-11-26

N-doped amorphous carbon coated Fe3O4/SnO2 coaxial nanofibers were prepared via a facile approach. The core composite nanofibers were first made by electrospinning technology, then the shells were conformally coated using the chemical bath deposition and subsequent carbonization with polydopamine as a carbon source. When applied as a binder-free self-supported anode for lithium ion batteries, the coaxial nanofibers displayed an enhanced electrochemical storage capacity and excellent rate performance. The morphology of the interwoven nanofibers was maintained even after the rate cycle test. The superior electrochemical performance originates in the structural stability of the N-doped amorphous carbon shells formed by carbonizing polydopamine.

A Mixed Multi-Field Finite Element Formulation for Thermopiezoelectric Composite Shells

NASA Technical Reports Server (NTRS)

Lee, Ho-Jun; Saravanos, Dimitris A.

1999-01-01

Analytical formulations are presented which account for the coupled mechanical, electrical, and thermal response of piezoelectric composite shell structures. A new mixed multi-field laminate theory is developed which combines "single layer" assumptions for the displacements along with layerwise fields for the electric potential and temperature. This laminate theory is formulated using curvilinear coordinates and is based on the principles of linear thermopiezoelectricity. The mechanics have the inherent capability to explicitly model both the active and sensory responses of piezoelectric composite shells in thermal environment. Finite element equations are derived and implemented for an eight-noded shell element. Numerical studies are conducted to investigate both the sensory and active responses of piezoelectric composite shell structures subjected to thermal loads. Results for a cantilevered plate with an attached piezoelectric layer are com- pared with corresponding results from a commercial finite element code and a previously developed program. Additional studies are conducted on a cylindrical shell with an attached piezoelectric layer to demonstrate capabilities to achieve thermal shape control on curved piezoelectric structures.

Microcapsules with a pH responsive polymer: influence of the encapsulated oil on the capsule morphology.

PubMed

Wagdare, Nagesh A; Marcelis, Antonius T M; Boom, Remko M; van Rijn, Cees J M

2011-11-01

Microcapsules were prepared by microsieve membrane cross flow emulsification of Eudragit FS 30D/dichloromethane/edible oil mixtures in water, and subsequent phase separation induced by extraction of the dichloromethane through an aqueous phase. For long-chain triglycerides and jojoba oil, core-shell particles were obtained with the oil as core, surrounded by a shell of Eudragit. Medium chain triglyceride (MCT oil) was encapsulated as relatively small droplets in the Eudragit matrix. The morphology of the formed capsules was investigated with optical and SEM microscopy. Extraction of the oil from the core-shell capsules with hexane resulted in hollow Eudragit capsules with porous shells. It was shown that the differences are related to the compatibility of the oils with the shell-forming Eudragit. An oil with poor compatibility yields microcapsules with a dense Eudragit shell on a single oil droplet as the core; oils having better compatibility yield porous Eudragit spheres with several oil droplets trapped inside. Copyright © 2011 Elsevier B.V. All rights reserved.

Thermal annealing dynamics of carbon-coated LiFePO4 nanoparticles studied by in-situ analysis

NASA Astrophysics Data System (ADS)

Krumeich, Frank; Waser, Oliver; Pratsinis, Sotiris E.

2016-10-01

The thermal behavior of core-shell carbon-coated lithium iron phosphate (LiFePO4-C) nanoparticles made by flame spray pyrolysis (FSP) during annealing was investigated by in-situ transmission electron microscopy (TEM), in-situ X-ray powder diffraction (XRD) as well as ex-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Crystallization of the initially glassy LiFePO4-C nanoparticles starts at quite low temperatures (T=400 °C), forming single crystals inside the confinement of the carbon shell. Upon increasing the temperature to T≥700 °C, LiFePO4 starts to diffuse through the carbon shell resulting in cavities inside the mostly intact carbon shell. By increasing the temperature further to T≥800 °C, the initial core-shell morphology converts into open carbon shells (flakes and cenospheres) and bulky LiFePO4 particles (diameter in the range 300-400 nm), in agreement with ex-situ experiments.

Slow-Injection Growth of Seeded CdSe/CdS Nanorods with Unity Fluorescence Quantum Yield and Complete Shell to Core Energy Transfer.

PubMed

Coropceanu, Igor; Rossinelli, Aurelio; Caram, Justin R; Freyria, Francesca S; Bawendi, Moungi G

2016-03-22

A two-step process has been developed for growing the shell of CdSe/CdS core/shell nanorods. The method combines an established fast-injection-based step to create the initial elongated shell with a second slow-injection growth that allows for a systematic variation of the shell thickness while maintaining a high degree of monodispersity at the batch level and enhancing the uniformity at the single-nanorod level. The second growth step resulted in nanorods exhibiting a fluorescence quantum yield up to 100% as well as effectively complete energy transfer from the shell to the core. This improvement suggests that the second step is associated with a strong suppression of the nonradiative channels operating both before and after the thermalization of the exciton. This hypothesis is supported by the suppression of a defect band, ubiquitous to CdSe-based nanocrystals after the second growth.

Elucidation of Two Giants: Challenges to Thick-shell Synthesis in CdSe/ZnSe and ZnSe/CdS Core/Shell Quantum Dots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Acharya, Krishna P.; Nguyen, Hue M.; Paulite, Melissa

2015-03-06

Core/thick-shell "giant" quantum dots (gQDs) possessing type II electronic structures exhibit suppressed blinking and diminished nonradiative Auger recombination. Here we investigate CdSe/ZnSe and ZnSe/CdS as potential new gQDs. We show theoretically and experimentally that both can exhibit partial or complete spatial separation of an excited-state electron–hole pair (i.e., type II behavior). However, we reveal that thick-shell growth is challenged by competing processes: alloying and cation exchange. We demonstrate that these can be largely avoided by choice of shelling conditions (e.g., time, temperature, and QD core identity). The resulting CdSe/ZnSe gQDs exhibit unusual single-QD properties, principally emitting from dim gray statesmore » but having high two-exciton (biexciton) emission efficiencies, whereas ZnSe/CdS gQDs show characteristic gQD blinking suppression, though only if shelling is accompanied by partial cation exchange.« less

Double shell planar experiments on OMEGA

NASA Astrophysics Data System (ADS)

Dodd, E. S.; Merritt, E. C.; Palaniyappan, S.; Montgomery, D. S.; Daughton, W. S.; Schmidt, D. W.; Cardenas, T.; Wilson, D. C.; Loomis, E. N.; Batha, S. H.; Ping, Y.; Smalyuk, V. A.; Amendt, P. A.

2017-10-01

The double shell project is aimed at fielding neutron-producing capsules at the National Ignition Facility (NIF), in which an outer low-Z ablator collides with an inner high-Z shell to compress the fuel. However, understanding these targets experimentally can be challenging when compared with conventional single shell targets. Halfraum-driven planar targets at OMEGA are being used to study physics issues important to double shell implosions outside of a convergent geometry. Both VISAR and radiography through a tube have advantages over imaging through the hohlraum and double-shell capsule at NIF. A number physics issues are being studied with this platform that include 1-d and higher dimensional effects such as defect-driven hydrodynamic instabilities from engineering features. Additionally, the use of novel materials with controlled density gradients require study in easily diagnosed 1-d systems. This work ultimately feeds back into the NIF capsule platform through manufacturing tolerances set using data from OMEGA. Supported under the US DOE by the LANS, LLC under contract DE-AC52-06NA25396. LA-UR-17-25386.

Current advances in precious metal core-shell catalyst design.

PubMed

Wang, Xiaohong; He, Beibei; Hu, Zhiyu; Zeng, Zhigang; Han, Sheng

2014-08-01

Precious metal nanoparticles are commonly used as the main active components of various catalysts. Given their high cost, limited quantity, and easy loss of catalytic activity under severe conditions, precious metals should be used in catalysts at low volumes and be protected from damaging environments. Accordingly, reducing the amount of precious metals without compromising their catalytic performance is difficult, particularly under challenging conditions. As multifunctional materials, core-shell nanoparticles are highly important owing to their wide range of applications in chemistry, physics, biology, and environmental areas. Compared with their single-component counterparts and other composites, core-shell nanoparticles offer a new active interface and a potential synergistic effect between the core and shell, making these materials highly attractive in catalytic application. On one hand, when a precious metal is used as the shell material, the catalytic activity can be greatly improved because of the increased surface area and the closed interfacial interaction between the core and the shell. On the other hand, when a precious metal is applied as the core material, the catalytic stability can be remarkably improved because of the protection conferred by the shell material. Therefore, a reasonable design of the core-shell catalyst for target applications must be developed. We summarize the latest advances in the fabrications, properties, and applications of core-shell nanoparticles in this paper. The current research trends of these core-shell catalysts are also highlighted.

Structural Characterization of Advanced Composite Tow-Steered Shells with Large Cutouts

NASA Technical Reports Server (NTRS)

Wu, K. Chauncey; Turpin, Jason D.; Gardner, Nathaniel W.; Stanford, Bret K.; Martin, Robert A.

2015-01-01

The structural performance of two advanced composite tow-steered shells with large cutouts, manufactured using an automated fiber placement system, is assessed using both experimental and analytical methods. The fiber orientation angles of the shells vary continuously around their circumference from +/- 10 degrees on the crown and keel, to +/- 45 degrees on the sides. The raised surface features on one shell result from application of all 24 tows during each fiber placement system pass, while the second shell uses the tow drop/add capability of the system to achieve a more uniform wall thickness. These unstiffened shells, both without and with small cutouts, were previously tested in axial compression and buckled elastically. In this study, a single unreinforced cutout, scaled to represent a cargo door on a commercial aircraft, is machined into one side of each shell. The prebuckling axial stiffnesses and bifurcation buckling loads of these shells with large cutouts are also computed using linear finite element structural analyses for preliminary comparisons with test data. During testing, large displacements are observed around the large cutouts, but the shells maintain an average of 91 percent of the axial stiffness, and also carry 85 percent of the buckling loads, when compared to the pristine shells without cutouts. These relatively small reductions indicate that there is great potential for using tow steering to mitigate the adverse effects of large cutouts on the overall structural performance.

Biocatalytic CO2 sequestration based on shell regeneration

NASA Astrophysics Data System (ADS)

Lee, S.

2012-04-01

Carbon dioxide, CO2, is one of the green gases, being uniformly distributed over the earth's surface. Recently, a variety of methods exists or has been proposed for pre- or post-emission capture and sequestration of CO2. However, CCS (carbon capture & storage) do not quarntee permanent treatment of CO2 and could ingenerate environment risks. Some organisms convert CO2 into exoskeleton (e.g., mollusks) or energy sources (e.g., plants) during metabolism under atmospheric conditions. One of representative biomaterials in ocean is bivalve shell to be composed of CaCO3. Calcium carbonate is not only abundant material in the world but also thermodynamically stable mineral in the capture of CO2. Bivalve has produced CaCO3 under seawater condition, in other word, near atmospheric conditions (1 atm. and around 20-25 oC). At the inorganic point, the synthesis of CaCO3 is as followed. Ca2+ + CO32- -> CaCO3 The bivalve shell plays an important role to protect bivalve's internal organs from prodetor. What will be happened if the shell is damaged and a hole is made? Bivalve must cover the hole to prevent the oxidation of internal organs as fast as possible. From in vitro crystallization test of a notched shell, rapid CaCO3 production was identified at the damaged area. The biocatalyst related to shell regeneration was purified and named as SPSR (Soluble Protein related to Shell Regeneration) that is obtained from the oyster, Crassostrea gigas. And in vitro CaCO3 crystallization test was used to calculate the crystal growth rate of SPSR on CaCO3 crystallization. The characteristics of SPRR are discussed at the point of CO2 hydration and rapid CaCO3 synthesis. To develop the bioinspired process based on shell regeneration concept, the analysis of protein structure has been studied and the immobilization has been carried out for easy recovery of SPSR.

Chaotic and regular instantons in helical shell models of turbulence

NASA Astrophysics Data System (ADS)

De Pietro, Massimo; Mailybaev, Alexei A.; Biferale, Luca

2017-03-01

Shell models of turbulence have a finite-time blowup in the inviscid limit, i.e., the enstrophy diverges while the single-shell velocities stay finite. The signature of this blowup is represented by self-similar instantonic structures traveling coherently through the inertial range. These solutions might influence the energy transfer and the anomalous scaling properties empirically observed for the forced and viscous models. In this paper we present a study of the instantonic solutions for a set of four shell models of turbulence based on the exact decomposition of the Navier-Stokes equations in helical eigenstates. We find that depending on the helical structure of each model, instantons are chaotic or regular. Some instantonic solutions tend to recover mirror symmetry for scales small enough. Models that have anomalous scaling develop regular nonchaotic instantons. Conversely, models that have nonanomalous scaling in the stationary regime are those that have chaotic instantons. The direction of the energy carried by each single instanton tends to coincide with the direction of the energy cascade in the stationary regime. Finally, we find that whenever the small-scale stationary statistics is intermittent, the instanton is less steep than the dimensional Kolmogorov scaling, independently of whether or not it is chaotic. Our findings further support the idea that instantons might be crucial to describe some aspects of the multiscale anomalous statistics of shell models.

Experimental investigation and micromagnetic simulations of hybrid CoCr2O4/Ni coaxial nanostructures.

PubMed

Li, W J; Wang, C J; Zhang, X M; Irfan, M; Khan, U; Liu, Y W; Han, X F

2018-06-15

Multiphase CoCr 2 O 4 /Ni core-shell nanowires (NWs) have been synthesized within anodic aluminum oxide membranes by the combination of the sol-gel method with electrodeposition techniques. X-ray diffraction and x-ray photoemission spectroscopy results confirmed the formation of a cubic spinel structure of CoCr 2 O 4 shell with space group Fd-3m (227). The morphology and composition of the as-grown NWs were studied by field emission scanning electron microscopy, as well as transmission electron microscopy. The magnetic properties of the CoCr 2 O 4 NT shell and hybrid CoCr 2 O 4 /Ni NWs were measured at low temperature using a physical property measurement system. The temperature dependence of the magnetization curves showed that CoCr 2 O 4 NTs undergo a transition from a paramagnetic state to a ferrimagnetic state at about 90 K and a spiral ordering transition temperature near 22 K. An enhanced coercivity and saturation field were observed for the CoCr 2 O 4 /Ni core-shell NWs compared to the single-phase Ni NWs. Micromagnetic simulation results indicated that there is a strong coupling between the shell and core layers during the magnetization reversal process. The combination of hard CoCr 2 O 4 and soft Ni in a single NW structure may have potential applications in future multifunctional devices.

Experimental investigation and micromagnetic simulations of hybrid CoCr2O4/Ni coaxial nanostructures

NASA Astrophysics Data System (ADS)

Li, W. J.; Wang, C. J.; Zhang, X. M.; Irfan, M.; Khan, U.; Liu, Y. W.; Han, X. F.

2018-06-01

Multiphase CoCr2O4/Ni core–shell nanowires (NWs) have been synthesized within anodic aluminum oxide membranes by the combination of the sol–gel method with electrodeposition techniques. X-ray diffraction and x-ray photoemission spectroscopy results confirmed the formation of a cubic spinel structure of CoCr2O4 shell with space group Fd-3m (227). The morphology and composition of the as-grown NWs were studied by field emission scanning electron microscopy, as well as transmission electron microscopy. The magnetic properties of the CoCr2O4 NT shell and hybrid CoCr2O4/Ni NWs were measured at low temperature using a physical property measurement system. The temperature dependence of the magnetization curves showed that CoCr2O4 NTs undergo a transition from a paramagnetic state to a ferrimagnetic state at about 90 K and a spiral ordering transition temperature near 22 K. An enhanced coercivity and saturation field were observed for the CoCr2O4/Ni core–shell NWs compared to the single-phase Ni NWs. Micromagnetic simulation results indicated that there is a strong coupling between the shell and core layers during the magnetization reversal process. The combination of hard CoCr2O4 and soft Ni in a single NW structure may have potential applications in future multifunctional devices.

Fully Disposable Manufacturing Concepts for Clinical and Commercial Manufacturing and Ballroom Concepts.

PubMed

Boedeker, Berthold; Goldstein, Adam; Mahajan, Ekta

2017-11-04

The availability and use of pre-sterilized disposables has greatly changed the methods used in biopharmaceuticals development and production, particularly from mammalian cell culture. Nowadays, almost all process steps from cell expansion, fermentation, cell removal, and purification to formulation and storage of drug substances can be carried out in disposables, although there are still limitations with single-use technologies, particularly in the areas of pretesting and quality control of disposables, bag and connections standardization and qualification, extractables and leachables (E/L) validation, and dependency on individual vendors. The current status of single-use technologies is summarized for all process unit operations using a standard mAb process as an example. In addition, current pros and cons of using disposables are addressed in a comparative way, including quality control and E/L validation.The continuing progress in developing single-use technologies has an important impact on manufacturing facilities, resulting in much faster, less expensive and simpler plant design, start-up, and operation, because cell culture process steps are no longer performed in hard-piped unit operations. This leads to simpler operations in a lab-like environment. Overall it enriches the current landscape of available facilities from standard hard-piped to hard-piped/disposables hybrid to completely single-use-based production plants using the current segregation and containment concept. At the top, disposables in combination with completely and functionally closed systems facilitate a new, revolutionary design of ballroom facilities without or with much less segregation, which enables us to perform good manufacturing practice manufacturing of different products simultaneously in unclassified but controlled areas.Finally, single-use processing in lab-like shell facilities is a big enabler of transferring and establishing production in emergent countries, and this is described in more detail in 7. Graphical Abstract.

Nuclear mass formula with the shell energies obtained by a new method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koura, H.; Tachibana, T.; Yamada, M.

1998-12-21

Nuclear shapes and masses are estimated by a new method. The main feature of this method lies in estimating shell energies of deformed nuclei from spherical shell energies by mixing them with appropriate weights. The spherical shell energies are calculated from single-particle potentials, and, till now, two mass formulas have been constructed from two different sets of potential parameters. The standard deviation of the calculated masses from all the experimental masses of the 1995 Mass Evaluation is about 760 keV. Contrary to the mass formula by Tachibana, Uno, Yamada and Yamada in the 1987-1988 Atomic Mass Predictions, the present formulasmore » can give nuclear shapes and predict on super-heavy elements.« less

Multidimensional Analysis of Direct-Drive Plastic-Shell Implosions on OMEGA

NASA Astrophysics Data System (ADS)

Radha, P. B.

2004-11-01

Direct-drive implosions of plastic shells with the OMEGA laser are used as energy-scaled warm surrogates for ignition cryogenic targets designed for use on the National Ignition Facility. Plastic targets involve varying shell thickness (15 to 33 μm), fill pressures (3 to 15 atm), and shell adiabats. The multidimensional hydrodynamics code DRACO is used to evaluate the effects of capsule-surface roughness and illumination nonuniformities on target performance. These simulations indicate that shell stability during the acceleration phase plays a critical role in determining fusion yields. For shells that are thick enough to survive the Rayleigh--Taylor growth, target yields are significantly reduced by growth of the long (ℓ < 10) and intermediate modes (20 < ℓ < 50) occurring from single-beam laser nonuniformities. The neutron production rate for these thick shells truncates relative to one-dimensional (1-D) predictions. The neutron-rate curves for the thinner shells, however, have significantly lower amplitudes and widths closer to 1-D results, indicating shell breakup during the acceleration phase. The simulation results are consistent with experimental observations. Previously, the stability of plastic-shell implosions had been correlated to a static ``mix-width'' at the boundary of the gas and plastic pusher estimated using a variety of experimental observables and an assumption of spherical symmetry. Results of these 2-D simulations provide a comprehensive understanding of warm-target implosion dynamics without assumptions of spherical symmetry and serve to answer the question of the hydrodynamic surrogacy between these plastic-shell implosions and the cryogenic ignition designs.

Waltzing route toward double-helix formation in cholesteric shells

NASA Astrophysics Data System (ADS)

Darmon, Alexandre; Benzaquen, Michael; Seč, David; Čopar, Simon; Dauchot, Olivier; Lopez-Leon, Teresa

2016-08-01

Liquid crystals, when confined to a spherical shell, offer fascinating possibilities for producing artificial mesoscopic atoms, which could then self-assemble into materials structured at a nanoscale, such as photonic crystals or metamaterials. The spherical curvature of the shell imposes topological constraints in the molecular ordering of the liquid crystal, resulting in the formation of defects. Controlling the number of defects, that is, the shell valency, and their positions, is a key success factor for the realization of those materials. Liquid crystals with helical cholesteric order offer a promising, yet unexplored way of controlling the shell defect configuration. In this paper, we study cholesteric shells with monovalent and bivalent defect configurations. By bringing together experiments and numerical simulations, we show that the defects appearing in these two configurations have a complex inner structure, as recently reported for simulated droplets. Bivalent shells possess two highly structured defects, which are composed of a number of smaller defect rings that pile up through the shell. Monovalent shells have a single radial defect, which is composed of two nonsingular defect lines that wind around each other in a double-helix structure. The stability of the bivalent configuration against the monovalent one is controlled by c = h/p, where h is the shell thickness and p the cholesteric helical pitch. By playing with the shell geometry, we can trigger the transition between the two configurations. This transition involves a fascinating waltz dynamics, where the two defects come closer while turning around each other.

A model study of aggregates composed of spherical soot monomers with an acentric carbon shell

NASA Astrophysics Data System (ADS)

Luo, Jie; Zhang, Yongming; Zhang, Qixing

2018-01-01

Influences of morphology on the optical properties of soot particles have gained increasing attentions. However, studies on the effect of the way primary particles are coated on the optical properties is few. Aimed to understand how the primary particles are coated affect the optical properties of soot particles, the coated soot particle was simulated using the acentric core-shell monomers model (ACM), which was generated by randomly moving the cores of concentric core-shell monomers (CCM) model. Single scattering properties of the CCM model with identical fractal parameters were calculated 50 times at first to evaluate the optical diversities of different realizations of fractal aggregates with identical parameters. The results show that optical diversities of different realizations for fractal aggregates with identical parameters cannot be eliminated by averaging over ten random realizations. To preserve the fractal characteristics, 10 realizations of each model were generated based on the identical 10 parent fractal aggregates, and then the results were averaged over each 10 realizations, respectively. The single scattering properties of all models were calculated using the numerically exact multiple-sphere T-matrix (MSTM) method. It is found that the single scattering properties of randomly coated soot particles calculated using the ACM model are extremely close to those using CCM model and homogeneous aggregate (HA) model using Maxwell-Garnett effective medium theory. Our results are different from previous studies. The reason may be that the differences in previous studies were caused by fractal characteristics but not models. Our findings indicate that how the individual primary particles are coated has little effect on the single scattering properties of soot particles with acentric core-shell monomers. This work provides a suggestion for scattering model simplification and model selection.

Ab initio description of p-shell hypernuclei.

PubMed

Wirth, Roland; Gazda, Daniel; Navrátil, Petr; Calci, Angelo; Langhammer, Joachim; Roth, Robert

2014-11-07

We present the first ab initio calculations for p-shell single-Λ hypernuclei. For the solution of the many-baryon problem, we develop two variants of the no-core shell model with explicit Λ and Σ(+),Σ(0),Σ(-) hyperons including Λ-Σ conversion, optionally supplemented by a similarity renormalization group transformation to accelerate model-space convergence. In addition to state-of-the-art chiral two- and three-nucleon interactions, we use leading-order chiral hyperon-nucleon interactions and a recent meson-exchange hyperon-nucleon interaction. We validate the approach for s-shell hypernuclei and apply it to p-shell hypernuclei, in particular to (Λ)(7)Li, (Λ)(9)Be, and (Λ)(13)C. We show that the chiral hyperon-nucleon interactions provide ground-state and excitation energies that generally agree with experiment within the cutoff dependence. At the same time we demonstrate that hypernuclear spectroscopy provides tight constraints on the hyperon-nucleon interactions.

Electrosprayed core-shell polymer-lipid nanoparticles for active component delivery

NASA Astrophysics Data System (ADS)

Eltayeb, Megdi; Stride, Eleanor; Edirisinghe, Mohan

2013-11-01

A key challenge in the production of multicomponent nanoparticles for healthcare applications is obtaining reproducible monodisperse nanoparticles with the minimum number of preparation steps. This paper focus on the use of electrohydrodynamic (EHD) techniques to produce core-shell polymer-lipid structures with a narrow size distribution in a single step process. These nanoparticles are composed of a hydrophilic core for active component encapsulation and a lipid shell. It was found that core-shell nanoparticles with a tunable size range between 30 and 90 nm and a narrow size distribution could be reproducibly manufactured. The results indicate that the lipid component (stearic acid) stabilizes the nanoparticles against collapse and aggregation and improves entrapment of active components, in this case vanillin, ethylmaltol and maltol. The overall structure of the nanoparticles produced was examined by multiple methods, including transmission electron microscopy and differential scanning calorimetry, to confirm that they were of core-shell form.

Non-parametric representation and prediction of single- and multi-shell diffusion-weighted MRI data using Gaussian processes

PubMed Central

Andersson, Jesper L.R.; Sotiropoulos, Stamatios N.

2015-01-01

Diffusion MRI offers great potential in studying the human brain microstructure and connectivity. However, diffusion images are marred by technical problems, such as image distortions and spurious signal loss. Correcting for these problems is non-trivial and relies on having a mechanism that predicts what to expect. In this paper we describe a novel way to represent and make predictions about diffusion MRI data. It is based on a Gaussian process on one or several spheres similar to the Geostatistical method of “Kriging”. We present a choice of covariance function that allows us to accurately predict the signal even from voxels with complex fibre patterns. For multi-shell data (multiple non-zero b-values) the covariance function extends across the shells which means that data from one shell is used when making predictions for another shell. PMID:26236030

Simulation of angular-resolved RABBITT measurements in noble-gas atoms

NASA Astrophysics Data System (ADS)

Bray, Alexander W.; Naseem, Faiza; Kheifets, Anatoli S.

2018-06-01

We simulate angular-resolved RABBITT (reconstruction of attosecond beating by interference of two-photon transitions) measurements on valence shells of noble-gas atoms (Ne, Ar, Kr, and Xe). Our nonperturbative numerical simulation is based on solution of the time-dependent Schrödinger equation (TDSE) for a target atom driven by an ionizing XUV and dressing IR fields. From these simulations we extract the angular-dependent magnitude and phase of the RABBITT oscillations and deduce the corresponding angular anisotropy β parameter and Wigner time delay τW for the single XUV photon absorption that initiates the RABBITT process. Said β and τW parameters are compared with calculations in the random-phase approximation with exchange (RPAE), which includes intershell correlation. This comparison is used to test various effective potentials employed in the one-electron TDSE. In lighter atoms (Ne and Ar), several effective potentials are found to provide accurate simulations of RABBITT measurements for a wide range of photon energies up to 100 eV above the valence-shell threshold. In heavier atoms (Kr and Xe), the onset of strong correlation with the d shell restricts the validity of the single active electron approximation to several tens of eV above the valence-shell threshold.

Near-K -edge single, double, and triple photoionization of C+ ions

NASA Astrophysics Data System (ADS)

Müller, A.; Borovik, A.; Buhr, T.; Hellhund, J.; Holste, K.; Kilcoyne, A. L. D.; Klumpp, S.; Martins, M.; Ricz, S.; Viefhaus, J.; Schippers, S.

2018-01-01

Single, double, and triple ionization of the C+ ion by a single photon have been investigated in the energy range 286 to 326 eV around the K -shell single-ionization threshold at an unprecedented level of detail. At energy resolutions as low as 12 meV, corresponding to a resolving power of 24 000, natural linewidths of the most prominent resonances could be determined. From the measurement of absolute cross sections, oscillator strengths, Einstein coefficients, multielectron Auger decay rates, and other transition parameters of the main K -shell excitation and decay processes are derived. The cross sections are compared to results of previous theoretical calculations. Mixed levels of agreement are found despite the relatively simple atomic structure of the C+ ion with only five electrons. This paper is a followup to a previous Letter [A. Müller et al., Phys. Rev. Lett. 114, 013002 (2015), 10.1103/PhysRevLett.114.013002].

Lateral Earth Pressure at Rest and Shear Modulus Measurements on Hanford Sludge Simulants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wells, Beric E.; Jenks, Jeromy WJ; Boeringa, Gregory K.

2010-09-30

This report describes the equipment, techniques, and results of lateral earth pressure at rest and shear modulus measurements on kaolin clay as well as two chemical sludge simulants. The testing was performed in support of the problem of hydrogen gas retention and release encountered in the double- shell tanks (DSTs) at the Hanford Site near Richland, Washington. Wastes from single-shell tanks (SSTs) are being transferred to double-shell tanks (DSTs) for safety reasons (some SSTs are leaking or are in danger of leaking), but the available DST space is limited.

Semiclassical Origin of Superdeformed Shell Structure in the Spheroidal Cavity Model

NASA Astrophysics Data System (ADS)

Arita, K.; Sugita, A.; Matsuyanagi, K.

1998-12-01

Classical periodic orbits responsible for emergence of the superdeformed shell structures of single-particle motion in spheroidal cavities are identified and their relative contributions to the shell structures are evaluated. Both prolate and oblate superdeformations (axis ratio approximately 2:1) as well as prolate hyperdeformation (axis ratio approximately 3:1) are investigated. Fourier transforms of quantum spectra clearly show that three-dimensional periodic orbits born out of bifurcations of planar orbits in the equatorial plane become predominant at large prolate deformations, while butterfly-shaped planar orbits bifurcated from linear orbits along the minor axis are important at large oblate deformations.

USSR Report, Engineering and Equipment, No. 98.

DTIC Science & Technology

1983-11-09

Nonhomogeneous Cylinder During Convective Cooling (V. Ya. Belousov; PROBLEM PROCHNOSTI, No 5, May 83) 66 Deformation of Spherical Shells Under Wind...generator and turbine, condenser , deaerator, and tap-water or hot-water tank for heat storage. The electric power is regulated by varying the steam rate...indicators, relative to those of hybrid condensation - boiler atomic electric power plants already in existence, So far the VK-500 boiling^water

Ag/Au/Polypyrrole Core-shell Nanowire Network for Transparent, Stretchable and Flexible Supercapacitor in Wearable Energy Devices

NASA Astrophysics Data System (ADS)

Moon, Hyunjin; Lee, Habeom; Kwon, Jinhyeong; Suh, Young Duk; Kim, Dong Kwan; Ha, Inho; Yeo, Junyeob; Hong, Sukjoon; Ko, Seung Hwan

2017-02-01

Transparent and stretchable energy storage devices have attracted significant interest due to their potential to be applied to biocompatible and wearable electronics. Supercapacitors that use the reversible faradaic redox reaction of conducting polymer have a higher specific capacitance as compared with electrical double-layer capacitors. Typically, the conducting polymer electrode is fabricated through direct electropolymerization on the current collector. However, no research have been conducted on metal nanowires as current collectors for the direct electropolymerization, even though the metal nanowire network structure has proven to be superior as a transparent, flexible, and stretchable electrode platform because the conducting polymer’s redox potential for polymerization is higher than that of widely studied metal nanowires such as silver and copper. In this study, we demonstrated a highly transparent and stretchable supercapacitor by developing Ag/Au/Polypyrrole core-shell nanowire networks as electrode by coating the surface of Ag NWs with a thin layer of gold, which provide higher redox potential than the electropolymerizable monomer. The Ag/Au/Polypyrrole core-shell nanowire networks demonstrated superior mechanical stability under various mechanical bending and stretching. In addition, proposed supercapacitors showed fine optical transmittance together with fivefold improved areal capacitance compared to pristine Ag/Au core-shell nanowire mesh-based supercapacitors.

Ag/Au/Polypyrrole Core-shell Nanowire Network for Transparent, Stretchable and Flexible Supercapacitor in Wearable Energy Devices

PubMed Central

Moon, Hyunjin; Lee, Habeom; Kwon, Jinhyeong; Suh, Young Duk; Kim, Dong Kwan; Ha, Inho; Yeo, Junyeob; Hong, Sukjoon; Ko, Seung Hwan

2017-01-01

Transparent and stretchable energy storage devices have attracted significant interest due to their potential to be applied to biocompatible and wearable electronics. Supercapacitors that use the reversible faradaic redox reaction of conducting polymer have a higher specific capacitance as compared with electrical double-layer capacitors. Typically, the conducting polymer electrode is fabricated through direct electropolymerization on the current collector. However, no research have been conducted on metal nanowires as current collectors for the direct electropolymerization, even though the metal nanowire network structure has proven to be superior as a transparent, flexible, and stretchable electrode platform because the conducting polymer’s redox potential for polymerization is higher than that of widely studied metal nanowires such as silver and copper. In this study, we demonstrated a highly transparent and stretchable supercapacitor by developing Ag/Au/Polypyrrole core-shell nanowire networks as electrode by coating the surface of Ag NWs with a thin layer of gold, which provide higher redox potential than the electropolymerizable monomer. The Ag/Au/Polypyrrole core-shell nanowire networks demonstrated superior mechanical stability under various mechanical bending and stretching. In addition, proposed supercapacitors showed fine optical transmittance together with fivefold improved areal capacitance compared to pristine Ag/Au core-shell nanowire mesh-based supercapacitors. PMID:28155913

Nano-Biotechnology in Using Enzymes for Environmental Remediation: Single-Enzyme Nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jungbae; Grate, Jay W.

2005-01-01

We have developed armored single-enzyme nanoparticles (SENs), which dramatically stabilize a protease (a-chymotrypsin, CT) by surrounding each enzyme molecule with a porous composite organic/inorganic shell of less than a few nanometers thick. The armored enzymes show no decrease in CT activity at 30°C for a day while free CT activity is rapidly reduced by orders of magnitude. The armored shell around CT is sufficiently thin and porous that it does not place any serious mass-transfer limitation of substrate. This unique approach will have a great impact in using enzymes in various fields, including environmental remediation.

Electronic state and photoionization cross section of a single dopant in GaN/InGaN core/shell quantum dot under magnetic field and hydrostatic pressure

NASA Astrophysics Data System (ADS)

Aouami, A. El; Feddi, E.; Talbi, A.; Dujardin, F.; Duque, C. A.

2018-06-01

In this study, we have investigated the simultaneous influence of magnetic field combined to the hydrostatic pressure and the geometrical confinement on the behavior of a single dopant confined in GaN/InGaN core/shell quantum dots. Within the scheme of the effective-mass approximation, the eigenvalues equation has solved by using the variational method with one-parameter trial wavefunctions. Variation of the ground state binding energy of the single dopant is determined according to the magnetic field and hydrostatic pressure for several dimensions of the heterostructure. The results show that the binding energy is strongly dependent on the core/shell sizes, the magnetic field, and the hydrostatic pressure. The analysis of the photoionization cross section, corresponding to optical transitions associated to the first donor energy level and the conduction band, shows clearly that the reduction of the dot dimensions and/or the simultaneous influences of applied magnetic field, combined to the hydrostatic pressure strength, cause a shift in resonance peaks towards the higher energies with important variations in the magnitude of the resonant peaks.

ZnS-Sb2S3@C Core-Double Shell Polyhedron Structure Derived from Metal-Organic Framework as Anodes for High Performance Sodium Ion Batteries.

PubMed

Dong, Shihua; Li, Caixia; Ge, Xiaoli; Li, Zhaoqiang; Miao, Xianguang; Yin, Longwei

2017-06-27

Taking advantage of zeolitic imidazolate framework (ZIF-8), ZnS-Sb 2 S 3 @C core-double shell polyhedron structure is synthesized through a sulfurization reaction between Zn 2+ dissociated from ZIF-8 and S 2- from thioacetamide (TAA), and subsequently a metal cation exchange process between Zn 2+ and Sb 3+ , in which carbon layer is introduced from polymeric resorcinol-formaldehyde to prevent the collapse of the polyhedron. The polyhedron composite with a ZnS inner-core and Sb 2 S 3 /C double-shell as anode for sodium ion batteries (SIBs) shows us a significantly improved electrochemical performance with stable cycle stability, high Coulombic efficiency and specific capacity. Peculiarly, introducing a carbon shell not only acts as an important protective layer to form a rigid construction and accommodate the volume changes, but also improves the electronic conductivity to optimize the stable cycle performance and the excellent rate property. The architecture composed of ZnS inner core and a complex Sb 2 S 3 /C shell not only facilitates the facile electrolyte infiltration to reduce the Na-ion diffusion length to improve the electrochemical reaction kinetics, but also prevents the structure pulverization caused by Na-ion insertion/extraction. This approach to prepare metal sulfides based on MOFs can be further extended to design other nanostructured systems for high performance energy storage devices.

Gastropod shell size and architecture influence the applicability of methods used to estimate internal volume.

PubMed

Ragagnin, Marilia Nagata; Gorman, Daniel; McCarthy, Ian Donald; Sant'Anna, Bruno Sampaio; de Castro, Cláudio Campi; Turra, Alexander

2018-01-11

Obtaining accurate and reproducible estimates of internal shell volume is a vital requirement for studies into the ecology of a range of shell-occupying organisms, including hermit crabs. Shell internal volume is usually estimated by filling the shell cavity with water or sand, however, there has been no systematic assessment of the reliability of these methods and moreover no comparison with modern alternatives, e.g., computed tomography (CT). This study undertakes the first assessment of the measurement reproducibility of three contrasting approaches across a spectrum of shell architectures and sizes. While our results suggested a certain level of variability inherent for all methods, we conclude that a single measure using sand/water is likely to be sufficient for the majority of studies. However, care must be taken as precision may decline with increasing shell size and structural complexity. CT provided less variation between repeat measures but volume estimates were consistently lower compared to sand/water and will need methodological improvements before it can be used as an alternative. CT indicated volume may be also underestimated using sand/water due to the presence of air spaces visible in filled shells scanned by CT. Lastly, we encourage authors to clearly describe how volume estimates were obtained.

Broadband absorption and enhanced photothermal conversion property of octopod-like Ag@Ag2S core@shell structures with gradually varying shell thickness.

PubMed

Jiang, Qian; Zeng, Wenxia; Zhang, Canying; Meng, Zhaoguo; Wu, Jiawei; Zhu, Qunzhi; Wu, Daxiong; Zhu, Haitao

2017-12-19

Photothermal conversion materials have promising applications in many fields and therefore they have attracted tremendous attention. However, the multi-functionalization of a single nanostructure to meet the requirements of multiple photothermal applications is still a challenge. The difficulty is that most nanostructures have specific absoprtion band and are not flexible to different demands. In the current work, we reported the synthesis and multi-band photothermal conversion of Ag@Ag 2 S core@shell structures with gradually varying shell thickness. We synthesized the core@shell structures through the sulfidation of Ag nanocubes by taking the advantage of their spatially different reactivity. The resulting core@shell structures show an octopod-like mopgorlogy with a Ag 2 S bulge sitting at each corner of the Ag nanocubes. The thickness of the Ag 2 S shell gradually increases from the central surface towards the corners of the structure. The synthesized core@shell structures show a broad band absorption spectrum from 300 to 1100 nm. Enhanced photothermal conversion effect is observed under the illuminations of 635, 808, and 1064 nm lasers. The results indicate that the octopod-like Ag@Ag 2 S core@shell structures have characteristics of multi-band photothermal conversion. The current work might provide a guidance for the design and synthesis of multifunctional photothermal conversion materials.

On the origin of the extended infrared shell around NGC 6888

NASA Astrophysics Data System (ADS)

Lozinskaya, T. A.; Pravdikova, V. V.; Gosachinskij, I. V.; Trushkin, S. A.

1997-06-01

The results of a program of research on the extended infrared shell around the nebula NGC 6888 and the star WR 136 are presented. We performed H-alpha observations with a Fabry-Perot interferometer mounted at the focus of a 125-cm telescope and radio continuum (2.7 to 31 cm) and 21-cm HI observations with the RATAN-600 radio telescope. A thick expanding shell of neutral hydrogen 120 pc in diameter that immediately surrounds the extended infrared shell was detected. This suggests that the infrared shell is a single structure rather than a projection of physically unrelated objects. The radial velocity of the HI shell is 11 +/- 1 km/s, the expansion velocity is 10 +/- 3 km/s, and the mass of the neutral hydrogen in the shell is 10 exp 4 solar masses. The bright radio features that we detected in the region of the infrared shell all exhibit a flat spectmm typical of thermal emission from optically thin HII regions. The same inference is probably also true for the nebula Simeiz 55. Our observations are consistent with the assumption of Marston that the extended shell was formed by the stellar wind from the precursor of WR 136, but they do not rule out the identification with a very old supernova remnant proposed by Nichols-Bohlin and Fesen.

Structural and Magnetic Response in Bimetallic Core/Shell Magnetic Nanoparticles

PubMed Central

Nairan, Adeela; Khan, Usman; Iqbal, Munawar; Khan, Maaz; Javed, Khalid; Riaz, Saira; Naseem, Shahzad; Han, Xiufeng

2016-01-01

Bimagnetic monodisperse CoFe2O4/Fe3O4 core/shell nanoparticles have been prepared by solution evaporation route. To demonstrate preferential coating of iron oxide onto the surface of ferrite nanoparticles X-ray diffraction (XRD), High resolution transmission electron microscope (HR-TEM) and Raman spectroscopy have been performed. XRD analysis using Rietveld refinement technique confirms single phase nanoparticles with average seed size of about 18 nm and thickness of shell is 3 nm, which corroborates with transmission electron microscopy (TEM) analysis. Low temperature magnetic hysteresis loops showed interesting behavior. We have observed large coercivity 15.8 kOe at T = 5 K, whereas maximum saturation magnetization (125 emu/g) is attained at T = 100 K for CoFe2O4/Fe3O4 core/shell nanoparticles. Saturation magnetization decreases due to structural distortions at the surface of shell below 100 K. Zero field cooled (ZFC) and Field cooled (FC) plots show that synthesized nanoparticles are ferromagnetic till room temperature and it has been noticed that core/shell sample possess high blocking temperature than Cobalt Ferrite. Results indicate that presence of iron oxide shell significantly increases magnetic parameters as compared to the simple cobalt ferrite. PMID:28335200

Strain history of ice shells of the Galilean satellites from radar detection of crystal orientation fabric

NASA Astrophysics Data System (ADS)

Barr, Amy C.; Stillman, David E.

2011-03-01

Orbital radar sounding has been suggested as a means of determining the subsurface thermal and physical structure of the outer ice I shells of the Galilean satellites. At radar frequencies, the dielectric permittivity of single- and polycrystalline water ice I is anisotropic. Crystal orientation fabric (COF), which is indicative of strain history, can be unambiguously detected by comparing the received power of dual co-polarization (linear polarization parallel and perpendicular to the orbit) radar data. Regions with crystal orientations dictated by the local strain field (“fabric”) form in terrestrial ice masses where accumulated strain and temperature are high, similar to conditions expected in a convecting outer ice I shell on Europa, Ganymede, or Callisto. We use simulations of solid-state ice shell convection to show that crystal orientation fabric can form in the warm convecting sublayer of the ice shells for plausible grain sizes. Changes in received power from parallel and perpendicular polarizations in the ice shells due to fabric could be detected if multi-polarization data is collected. With proper instrument design, radar sounding could be used to shed light on the strain history of the satellites' ice shells in addition to their present day internal structures.

One-by-one imprinting in two eccentric layers of hollow core-shells: Sequential electroanalysis of anti-HIV drugs.

PubMed

Singh, Kislay; Jaiswal, Swadha; Singh, Richa; Fatma, Sana; Prasad, Bhim Bali

2018-07-15

Double layered one-by-one imprinted hollow core-shells@ pencil graphite electrode was fabricated for sequential sensing of anti-HIV drugs. For this, two eccentric layers were developed on the surface of vinylated silica nanospheres to obtain double layered one-by-one imprinted solid core-shells. This yielded hollow core-shells on treatment with hydrofluoric acid. The modified hollow core-shells (single layered dual imprinted) evolved competitive diffusion of probe/analyte molecules. However, the corresponding double layered one-by-one imprinted hollow core-shells (outer layer imprinted with Zidovudine, and inner layer with Lamivudine) were found relatively better owing to their bilateral diffusions into molecular cavities, without any competition. The entire work is based on differential pulse anodic stripping voltammetry at double layered one-by-one imprinted hollow core-shells. This resulted in indirect detection of electro inactive targets with limits of detection as low as 0.91 and 0.12 (aqueous sample), 0.94 and 0.13 (blood serum), and 0.99 and 0.20 ng mL -1 (pharmaceutics) for lamivudine and zidovudine, respectively in anti-HIV drug combination. Copyright © 2018 Elsevier B.V. All rights reserved.

Kinetic Energy Transfer Process in a Double Shell Leading to Robust Burn

NASA Astrophysics Data System (ADS)

Montgomery, D. S.; Daughton, W. S.; Albright, B. J.; Wilson, D. C.; Loomis, E. N.; Merritt, E. C.; Dodd, E. S.; Kirkpatrick, R. C.; Watt, R. G.; Rosen, M. D.

2017-10-01

A goal of double shell capsule implosions is to impart sufficient internal energy to the D-T fuel at stagnation in order to obtain robust α-heating and burn with low hot spot convergence, C.R. < 10. A simple description of the kinetic energy transfer from the outer shell to the inner shell is found using shock physics and adiabatic compression, and compares well with 1D modeling. An isobaric model for the stagnation phase of the inner shell is used to determine the ideal partition of internal energy in the D-T fuel. Robust burn of the fuel requires, at minimum, that α-heating exceeds the rate of cooling by expansion of the hot spot so that the yield occurs before the hot spot disassembles, which is then used to define a minimum requirement for robust burn. One potential advantage of a double shell capsule compared to single shell capsules is the use of a heavy metal pusher, which may lead to a longer hot spot disassembly time. We present these analytic results and compare them to 1D and 2D radiation-hydrodynamic simulations. Work performed under the auspices of DOE by LANL under contract DE-AC52-06NA25396.

Solar heating and hot water system installed at Saint Louis, Missouri

NASA Technical Reports Server (NTRS)

1980-01-01

The solar heating and hot water system installed at the William Tao & Associates, Inc., office building in St. Louis, Missouri is described, including maintenance and construction problems, final drawings, system requirements, and manufacturer's component data. The solar system was designed to provide 50 percent of the hot water requirements and 45 percent of the space heating needs for a 900 sq ft office space and drafting room. The solar facility has 252 sq ft of glass tube concentrator collectors and a 1000 gallon steel storage tank buried below a concrete slab floor. Freeze protection is provided by a propylene glycol/water mixture in the collector loop. The collectors are roof mounted on a variable tilt array which is adjusted seasonally and is connected to the solar thermal storage tank by a tube-in-shell heat exchanger. Incoming city water is preheated through the solar energy thermal storage tank.

Silk micrococoons for protein stabilisation and molecular encapsulation

NASA Astrophysics Data System (ADS)

Shimanovich, Ulyana; Ruggeri, Francesco S.; de Genst, Erwin; Adamcik, Jozef; Barros, Teresa P.; Porter, David; Müller, Thomas; Mezzenga, Raffaele; Dobson, Christopher M.; Vollrath, Fritz; Holland, Chris; Knowles, Tuomas P. J.

2017-07-01

Naturally spun silks generate fibres with unique properties, including strength, elasticity and biocompatibility. Here we describe a microfluidics-based strategy to spin liquid native silk, obtained directly from the silk gland of Bombyx mori silkworms, into micron-scale capsules with controllable geometry and variable levels of intermolecular β-sheet content in their protein shells. We demonstrate that such micrococoons can store internally the otherwise highly unstable liquid native silk for several months and without apparent effect on its functionality. We further demonstrate that these native silk micrococoons enable the effective encapsulation, storage and release of other aggregation-prone proteins, such as functional antibodies. These results show that native silk micrococoons are capable of preserving the full activity of sensitive cargo proteins that can aggregate and lose function under conditions of bulk storage, and thus represent an attractive class of materials for the storage and release of active biomolecules.

OWL: A code for the two-center shell model with spherical Woods-Saxon potentials

NASA Astrophysics Data System (ADS)

Diaz-Torres, Alexis

2018-03-01

A Fortran-90 code for solving the two-center nuclear shell model problem is presented. The model is based on two spherical Woods-Saxon potentials and the potential separable expansion method. It describes the single-particle motion in low-energy nuclear collisions, and is useful for characterizing a broad range of phenomena from fusion to nuclear molecular structures.

Experimental data on the properties of natural fiber particle reinforced polymer composite material.

PubMed

Chandramohan, D; Presin Kumar, A John

2017-08-01

This paper presents an experimental study on the development of polymer bio-composites. The powdered coconut shell, walnut shells and Rice husk are used as reinforcements with bio epoxy resin to form hybrid composite specimens. The fiber compositions in each specimen are 1:1 while the resin and hardener composition 10:1 respectively. The fabricated composites were tested as per ASTM standards to evaluate mechanical properties such as tensile strength, flexural strength, shear strength and impact strength are evaluated in both with moisture and without moisture. The result of test shows that hybrid composite has far better properties than single fibre glass reinforced composite under mechanical loads. However it is found that the incorporation of walnut shell and coconut shell fibre can improve the properties.

Three-dimensional bicontinuous nanoporous Au/polyaniline hybrid films for high-performance electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Lang, Xingyou; Zhang, Ling; Fujita, Takeshi; Ding, Yi; Chen, Mingwei

2012-01-01

We report three-dimensional bicontinuous nanoporous Au/polyaniline (PANI) composite films made by one-step electrochemical polymerization of PANI shell onto dealloyed nanoporous gold (NPG) skeletons for the applications in electrochemical supercapacitors. The NPG/PANI based supercapacitors exhibit ultrahigh volumetric capacitance (∼1500 F cm-3) and energy density (∼0.078 Wh cm-3), which are seven and four orders of magnitude higher than these of electrolytic capacitors, with the same power density up to ∼190 W cm-3. The outstanding capacitive performances result from a novel nanoarchitecture in which pseudocapacitive PANI shells are incorporated into pore channels of highly conductive NPG, making them promising candidates as electrode materials in supercapacitor devices combing high-energy storage densities with high-power delivery.

Hanford Double-Shell Tank AY-102 Radioactive Waste Leak Investigation Update - 15302

DOE Office of Scientific and Technical Information (OSTI.GOV)

Washenfelder, D. J.; Johnson, J. M.

2014-12-22

Tank AY-102 was the first of 28 double-shell radioactive waste storage tanks constructed at the U. S. Department of Energy’s Hanford Site, near Richland, WA. The tank was completed in 1970, and entered service in 1971. In August, 2012, an accumulation of material was discovered at two sites on the floor of the annulus that separates the primary tank from the secondary liner. The material was sampled and determined to originate from the primary tank. This paper summarizes the changes in leak behavior that have occurred during the past two years, inspections to determine the capability of the secondary linermore » to continue safely containing the leakage, and the initial results of testing to determine the leak mechanism.« less

Efficient and accurate local single reference correlation methods for high-spin open-shell molecules using pair natural orbitals

NASA Astrophysics Data System (ADS)

Hansen, Andreas; Liakos, Dimitrios G.; Neese, Frank

2011-12-01

A production level implementation of the high-spin open-shell (spin unrestricted) single reference coupled pair, quadratic configuration interaction and coupled cluster methods with up to doubly excited determinants in the framework of the local pair natural orbital (LPNO) concept is reported. This work is an extension of the closed-shell LPNO methods developed earlier [F. Neese, F. Wennmohs, and A. Hansen, J. Chem. Phys. 130, 114108 (2009), 10.1063/1.3086717; F. Neese, A. Hansen, and D. G. Liakos, J. Chem. Phys. 131, 064103 (2009), 10.1063/1.3173827]. The internal space is spanned by localized orbitals, while the external space for each electron pair is represented by a truncated PNO expansion. The laborious integral transformation associated with the large number of PNOs becomes feasible through the extensive use of density fitting (resolution of the identity (RI)) techniques. Technical complications arising for the open-shell case and the use of quasi-restricted orbitals for the construction of the reference determinant are discussed in detail. As in the closed-shell case, only three cutoff parameters control the average number of PNOs per electron pair, the size of the significant pair list, and the number of contributing auxiliary basis functions per PNO. The chosen threshold default values ensure robustness and the results of the parent canonical methods are reproduced to high accuracy. Comprehensive numerical tests on absolute and relative energies as well as timings consistently show that the outstanding performance of the LPNO methods carries over to the open-shell case with minor modifications. Finally, hyperfine couplings calculated with the variational LPNO-CEPA/1 method, for which a well-defined expectation value type density exists, indicate the great potential of the LPNO approach for the efficient calculation of molecular properties.

Bistable mixed-valence molecular architectures for bit storage

NASA Astrophysics Data System (ADS)

Guihery, Nathalie; Durand, Gérard; Lepetit, Marie-Bernadette

1994-05-01

The work examines the possible realization of bit storage at the molecular scale using mixed valence compounds i.e. the existence of two stable and degenerate forms associated with the 0 and 1 positions of the bit. The proposed systems are constituted of two donors (D) and acceptor (A), or one donor and two acceptors, juxtaposed in DAD or ADA architectures. Our proposals take advantage of the possibility of donor—acceptor complexes to exhibit either complete or partial charge transfer. The first system we propose has an essentially neutral ground state. However, the potential energy surface (PES) presents two degenerated minima associated with a partial charge transfer between the donor and one of the two acceptor molecules (A δ-D δ+1 A and AD δ+ A δ-). Systems presenting a complete charge transfer give rise to two stable, weakly coupled, and degenerate ionic electronic states, A - A + A and AD + A - for an ADA architecture and D + A -D and DA -D + for a DAD In these cases, the two forms differ by both their intramolecular geometries and the relative positions of their constituents. It seems rather difficult to conceive such bistable molecular systems using closed-shell molecules, while a donor radical and a closed-shell acceptor or an acceptor radical and closed-shell donor can generate very stable ionic states. It is assumed that the relative positions of the donor and acceptor molecules can be fixed using chemical bridges constituted of rigid or flexible ligands. The writing and reading processes are discussed for each system as well as the information stability when a large number of bits are juxtaposed on a surface.

Model-based analysis of the torsional loss modulus in human hair and of the effects of cosmetic processing.

PubMed

Wortmann, Franz J; Wortmann, Gabriele; Haake, Hans-Martin; Eisfeld, Wolf

Torsional analysis of single human hairs is especially suited to determine the properties of the cuticle and its changes through cosmetic processing. The two primary parameters, which are obtained by free torsional oscillation using the torsional pendulum method, are storage ( G ') and loss modulus ( G ″). Based on previous work on G ', the current investigation focuses on G ″. The results show an increase of G ″ with a drop of G ' and vice versa , as is expected for a viscoelastic material well below its glass transition. The overall power of G ″ to discriminate between samples is quite low. This is attributed to the systematic decrease of the parameter values with increasing fiber diameter, with a pronounced correlation between G ″ and G '. Analyzing this effect on the basis of a core/shell model for the cortex/cuticle structure of hair by nonlinear regression leads to estimates for the loss moduli of cortex ( G ″ co ) and cuticle ( G ″ cu ). Although the values for G ″ co turn out to be physically not plausible, due to limitations of the applied model, those for G ″ cu are considered as generally realistic against relevant literature values. Significant differences between the loss moduli of the cuticle for the different samples provide insight into changes of the torsional energy loss due to the cosmetic processes and products, contributing toward a consistent view of torsional energy storage and loss, namely, in the cuticle of hair.

Synthesis and magnetic properties of cobalt-iron/cobalt-ferrite soft/hard magnetic core/shell nanowires

NASA Astrophysics Data System (ADS)

Leandro Londoño-Calderón, César; Moscoso-Londoño, Oscar; Muraca, Diego; Arzuza, Luis; Carvalho, Peterson; Pirota, Kleber Roberto; Knobel, Marcelo; Pampillo, Laura Gabriela; Martínez-García, Ricardo

2017-06-01

A straightforward method for the synthesis of CoFe2.7/CoFe2O4 core/shell nanowires is described. The proposed method starts with a conventional pulsed electrodeposition procedure on alumina nanoporous template. The obtained CoFe2.7 nanowires are released from the template and allowed to oxidize at room conditions over several weeks. The effects of partial oxidation on the structural and magnetic properties were studied by x-ray spectrometry, magnetometry, and scanning and transmission electron microscopy. The results indicate that the final nanowires are composed of 5 nm iron-cobalt alloy nanoparticles. Releasing the nanowires at room conditions promoted surface oxidation of the nanoparticles and created a CoFe2O4 shell spinel-like structure. The shell avoids internal oxidation and promotes the formation of bi-magnetic soft/hard magnetic core/shell nanowires. The magnetic properties of both the initial single-phase CoFe2.7 nanowires and the final core/shell nanowires, reveal that the changes in the properties from the array are due to the oxidation more than effects associated with released processes (disorder and agglomeration).

Synthesis and magnetic properties of cobalt-iron/cobalt-ferrite soft/hard magnetic core/shell nanowires.

PubMed

Londoño-Calderón, César Leandro; Moscoso-Londoño, Oscar; Muraca, Diego; Arzuza, Luis; Carvalho, Peterson; Pirota, Kleber Roberto; Knobel, Marcelo; Pampillo, Laura Gabriela; Martínez-García, Ricardo

2017-06-16

A straightforward method for the synthesis of CoFe 2.7 /CoFe 2 O 4 core/shell nanowires is described. The proposed method starts with a conventional pulsed electrodeposition procedure on alumina nanoporous template. The obtained CoFe 2.7 nanowires are released from the template and allowed to oxidize at room conditions over several weeks. The effects of partial oxidation on the structural and magnetic properties were studied by x-ray spectrometry, magnetometry, and scanning and transmission electron microscopy. The results indicate that the final nanowires are composed of 5 nm iron-cobalt alloy nanoparticles. Releasing the nanowires at room conditions promoted surface oxidation of the nanoparticles and created a CoFe 2 O 4 shell spinel-like structure. The shell avoids internal oxidation and promotes the formation of bi-magnetic soft/hard magnetic core/shell nanowires. The magnetic properties of both the initial single-phase CoFe 2.7 nanowires and the final core/shell nanowires, reveal that the changes in the properties from the array are due to the oxidation more than effects associated with released processes (disorder and agglomeration).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eriksen, Janus J., E-mail: janusje@chem.au.dk; Jørgensen, Poul; Matthews, Devin A.

The accuracy at which total energies of open-shell atoms and organic radicals may be calculated is assessed for selected coupled cluster perturbative triples expansions, all of which augment the coupled cluster singles and doubles (CCSD) energy by a non-iterative correction for the effect of triple excitations. Namely, the second- through sixth-order models of the recently proposed CCSD(T–n) triples series [J. J. Eriksen et al., J. Chem. Phys. 140, 064108 (2014)] are compared to the acclaimed CCSD(T) model for both unrestricted as well as restricted open-shell Hartree-Fock (UHF/ROHF) reference determinants. By comparing UHF- and ROHF-based statistical results for a test setmore » of 18 modest-sized open-shell species with comparable RHF-based results, no behavioral differences are observed for the higher-order models of the CCSD(T–n) series in their correlated descriptions of closed- and open-shell species. In particular, we find that the convergence rate throughout the series towards the coupled cluster singles, doubles, and triples (CCSDT) solution is identical for the two cases. For the CCSD(T) model, on the other hand, not only its numerical consistency, but also its established, yet fortuitous cancellation of errors breaks down in the transition from closed- to open-shell systems. The higher-order CCSD(T–n) models (orders n > 3) thus offer a consistent and significant improvement in accuracy relative to CCSDT over the CCSD(T) model, equally for RHF, UHF, and ROHF reference determinants, albeit at an increased computational cost.« less

Stretched proton-neutron configurations in fp-shell nuclei (II). Systematics

NASA Astrophysics Data System (ADS)

von Neumann-Cosel, P.; Fister, U.; Jahn, R.; Schenk, P.; Trelle, T. K.; Wenzel, D.; Wienands, U.

1994-03-01

The systematics of the binding energies of stretched proton-neutron configurations ( f{7}/{2}, g{9}/{2}) 8 -, ( p{3}/{2}, g{9}/{2}) 6 -, ( g{9}/{2}, p{3}/{2}) 6- and ( g{9}/{2}) 29 + are studied over a wide range of f p-shell nuclei. The effective proton-neutron interaction energies deduced from the data are nearly constant for ( p{3}/{2}, g{9}/{2}) 6 -and ( g{9}/{2}) 29 + states while the ( f{7}/{2}, g{9}/{2}) 8 - configuration reveals an additional repulsive term proportional to the partial filling of the f{7}/{2} orbit in the target ground state. Two-body matrix elements are extracted. A crude shell model, which predicts that the excitation energy of a stretched state is equal to the sum of the single-particle energies, works well for the 6 - and 9 + states, but fails for the 8 - levels due to neglect of the additional interactions described above. The physics underlying the empirically introduced basic assumptions of the crude shell model is discussed. The binding energies are found to be linearly dependent on the mass number A and the isospin Tz component and are well described by the weak-coupling model of Bansal and French. The derived parameters agree with averaged values of a similar analysis for the single-particle states in the corresponding odd-even neighbours. The data indicate a significant change of the particle-hole energies with closure of the proton f{7}/{2} shell.

Multicore-shell nanofiber architecture of polyimide/polyvinylidene fluoride blend for thermal and long-term stability of lithium ion battery separator.

PubMed

Park, Sejoon; Son, Chung Woo; Lee, Sungho; Kim, Dong Young; Park, Cheolmin; Eom, Kwang Sup; Fuller, Thomas F; Joh, Han-Ik; Jo, Seong Mu

2016-11-11

Li-ion battery, separator, multicoreshell structure, thermal stability, long-term stability. A nanofibrous membrane with multiple cores of polyimide (PI) in the shell of polyvinylidene fluoride (PVdF) was prepared using a facile one-pot electrospinning technique with a single nozzle. Unique multicore-shell (MCS) structure of the electrospun composite fibers was obtained, which resulted from electrospinning a phase-separated polymer composite solution. Multiple PI core fibrils with high molecular orientation were well-embedded across the cross-section and contributed remarkable thermal stabilities to the MCS membrane. Thus, no outbreaks were found in its dimension and ionic resistance up to 200 and 250 °C, respectively. Moreover, the MCS membrane (at ~200 °C), as a lithium ion battery (LIB) separator, showed superior thermal and electrochemical stabilities compared with a widely used commercial separator (~120 °C). The average capacity decay rate of LIB for 500 cycles was calculated to be approximately 0.030 mAh/g/cycle. This value demonstrated exceptional long-term stability compared with commercial LIBs and with two other types (single core-shell and co-electrospun separators incorporating with functionalized TiO 2 ) of PI/PVdF composite separators. The proper architecture and synergy effects of multiple PI nanofibrils as a thermally stable polymer in the PVdF shell as electrolyte compatible polymers are responsible for the superior thermal performance and long-term stability of the LIB.

Multicore-shell nanofiber architecture of polyimide/polyvinylidene fluoride blend for thermal and long-term stability of lithium ion battery separator

PubMed Central

Park, Sejoon; Son, Chung Woo; Lee, Sungho; Kim, Dong Young; Park, Cheolmin; Eom, Kwang Sup; Fuller, Thomas F.; Joh, Han-Ik; Jo, Seong Mu

2016-01-01

Li-ion battery, separator, multicoreshell structure, thermal stability, long-term stability. A nanofibrous membrane with multiple cores of polyimide (PI) in the shell of polyvinylidene fluoride (PVdF) was prepared using a facile one-pot electrospinning technique with a single nozzle. Unique multicore-shell (MCS) structure of the electrospun composite fibers was obtained, which resulted from electrospinning a phase-separated polymer composite solution. Multiple PI core fibrils with high molecular orientation were well-embedded across the cross-section and contributed remarkable thermal stabilities to the MCS membrane. Thus, no outbreaks were found in its dimension and ionic resistance up to 200 and 250 °C, respectively. Moreover, the MCS membrane (at ~200 °C), as a lithium ion battery (LIB) separator, showed superior thermal and electrochemical stabilities compared with a widely used commercial separator (~120 °C). The average capacity decay rate of LIB for 500 cycles was calculated to be approximately 0.030 mAh/g/cycle. This value demonstrated exceptional long-term stability compared with commercial LIBs and with two other types (single core-shell and co-electrospun separators incorporating with functionalized TiO2) of PI/PVdF composite separators. The proper architecture and synergy effects of multiple PI nanofibrils as a thermally stable polymer in the PVdF shell as electrolyte compatible polymers are responsible for the superior thermal performance and long-term stability of the LIB. PMID:27833132

Design of 8-ft-Diameter Barrel Test Article Attachment Rings for Shell Buckling Knockdown Factor Project

NASA Technical Reports Server (NTRS)

Lovejoy, Andrew E.; Hilburger, Mark W.

2010-01-01

The Shell Buckling Knockdown Factor (SBKF) project includes the testing of sub-scale cylinders to validate new shell buckling knockdown factors for use in the design of the Ares-I and Ares-V launch vehicles. Test article cylinders represent various barrel segments of the Ares-I and Ares-V vehicles, and also include checkout test articles. Testing will be conducted at Marshall Space Flight Center (MSFC) for test articles having an eight-foot diameter outer mold line (OML) and having lengths that range from three to ten feet long. Both ends of the test articles will be connected to the test apparatus using attachment rings. Three multiple-piece and one single-piece design for the attachment rings were developed and analyzed. The single-piece design was chosen and will be fabricated from either steel or aluminum (Al) depending on the required safety factors (SF) for test hardware. This report summarizes the design and analysis of these attachment ring concepts.

Single-neutron orbits near 78Ni: Spectroscopy of the N = 49 isotope 79Zn

DOE PAGES

Orlandi, R.; Mücher, D.; Raabe, R.; ...

2014-12-09

Single-neutron states in the Z=30, N=49 isotope 79Zn have been populated using the 78Zn(d, p) 79Zn transfer reaction at REX-ISOLDE, CERN. The experimental setup allowed the combined detection of protons ejected in the reaction, and of γ rays emitted by 79Zn. The analysis reveals that the lowest excited states populated in the reaction lie at approximately 1 MeV of excitation, and involve neutron orbits above the N=50 shell gap. From the analysis of γ -ray data and of proton angular distributions, characteristic of the amount of angular momentum transferred, a 5/2 + configuration was assigned to a state at 983more » keV. Comparison with large-scale-shell-model calculations supports a robust neutron N=50 shell-closure for 78Ni. Finally, these data constitute an important step towards the understanding of the magicity of 78Ni and of the structure of nuclei in the region.« less

X-ray transitions studied for decelerated bare and H-like uranium ions at the ESR electron cooler

NASA Astrophysics Data System (ADS)

Gumberidze, A.; Stöhlker, Th.; Bednarz, G.; Beyer, H. F.; Bosch, F.; Cai, X.; Hagmann, S.; Klepper, O.; Kozhuharov, C.; Liesen, D.; Ma, X.; Mokler, P. H.; Sierpowski, D.; Stachura, Z.; Steck, M.; Toleikis, S.; Warczak, A.; Zou, Y.

2003-05-01

Here we report on X-ray spectra induced by spontaneous capture of free electrons into decelerated bare- and hydrogen-like uranium ions which we measured recently at the cooler section of the ESR storage ring. The most intense lines observed in spectra can be attributed to direct transition of electrons into the K shell of the projectile ions and to characteristic L → K (Lyα) transitions. Radiative recombination lines into the K shell of bare and H-like uranium can be exploited for measuring the two-electron contribution to the ground state binding energy in helium-like uranium. The goal is to probe for high-Z ions bound-state QED corrections which are of the order of α2. Besides the dominant characteristic L → K transitions, the strongly reduced Bremsstrahlung (due to the low cooler voltage applied to the decelerated ions) allowed us to observe for the very first time RR transitions into the L shell as well as the balmer radiation located at the low-energy part of the spectra.

High-Performance One-Body Core/Shell Nanowire Supercapacitor Enabled by Conformal Growth of Capacitive 2D WS2 Layers.

PubMed

Choudhary, Nitin; Li, Chao; Chung, Hee-Suk; Moore, Julian; Thomas, Jayan; Jung, Yeonwoong

2016-12-27

Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have emerged as promising capacitive materials for supercapacitor devices owing to their intrinsically layered structure and large surface areas. Hierarchically integrating 2D TMDs with other functional nanomaterials has recently been pursued to improve electrochemical performances; however, it often suffers from limited cyclic stabilities and capacitance losses due to the poor structural integrity at the interfaces of randomly assembled materials. Here, we report high-performance core/shell nanowire supercapacitors based on an array of one-dimensional (1D) nanowires seamlessly integrated with conformal 2D TMD layers. The 1D and 2D supercapacitor components possess "one-body" geometry with atomically sharp and structurally robust core/shell interfaces, as they were spontaneously converted from identical metal current collectors via sequential oxidation/sulfurization. These hybrid supercapacitors outperform previously developed any stand-alone 2D TMD-based supercapacitors; particularly, exhibiting an exceptional charge-discharge retention over 30,000 cycles owing to their structural robustness, suggesting great potential for unconventional energy storage technologies.

Experimental aspects of the adiabatic approach in estimating the effect of electron screening on alpha decay

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karpeshin, F. F., E-mail: fkarpeshin@gmail.com; Trzhaskovskaya, M. B.

2015-12-15

Special features of the effect of the electron shell on alpha decay that have important experimental implications are studied within the adiabatic approach. The magnitude of the effect is about several tenths of a percent or smaller, depending on the transition energy and on the atomic number. A dominant role of inner shells is shown: more than 80% of the effect is saturated by 1s electrons. This circumstance plays a crucial role for experiments, making it possible to measure this small effect by a difference method in the same storage rings via a comparison of, for example, decay probabilities inmore » bare nuclei and heliumlike ions. The reasons behind the relative success and the applicability limits of the frozen-shell model, which has been used to calculate the effect in question for more than half a century, are analyzed. An interesting experiment aimed at studying charged alpha-particle states is proposed. This experiment will furnish unique information for testing our ideas of the interplay of nonadiabatic and adiabatic processes.« less

Highly efficient siRNA delivery from core-shell mesoporous silica nanoparticles with multifunctional polymer caps

NASA Astrophysics Data System (ADS)

Möller, Karin; Müller, Katharina; Engelke, Hanna; Bräuchle, Christoph; Wagner, Ernst; Bein, Thomas

2016-02-01

A new general route for siRNA delivery is presented combining porous core-shell silica nanocarriers with a modularly designed multifunctional block copolymer. Specifically, the internal storage and release of siRNA from mesoporous silica nanoparticles (MSN) with orthogonal core-shell surface chemistry was investigated as a function of pore-size, pore morphology, surface properties and pH. Very high siRNA loading capacities of up to 380 μg per mg MSN were obtained with charge-matched amino-functionalized mesoporous cores, and release profiles show up to 80% siRNA elution after 24 h. We demonstrate that adsorption and desorption of siRNA is mainly driven by electrostatic interactions, which allow for high loading capacities even in medium-sized mesopores with pore diameters down to 4 nm in a stellate pore morphology. The negatively charged MSN shell enabled the association with a block copolymer containing positively charged artificial amino acids and oleic acid blocks, which acts simultaneously as capping and endosomal release agent. The potential of this multifunctional delivery platform is demonstrated by highly effective cell transfection and siRNA delivery into KB-cells. A luciferase reporter gene knock-down of up to 80-90% was possible using extremely low cell exposures with only 2.5 μg MSN containing 0.5 μg siRNA per 100 μL well.A new general route for siRNA delivery is presented combining porous core-shell silica nanocarriers with a modularly designed multifunctional block copolymer. Specifically, the internal storage and release of siRNA from mesoporous silica nanoparticles (MSN) with orthogonal core-shell surface chemistry was investigated as a function of pore-size, pore morphology, surface properties and pH. Very high siRNA loading capacities of up to 380 μg per mg MSN were obtained with charge-matched amino-functionalized mesoporous cores, and release profiles show up to 80% siRNA elution after 24 h. We demonstrate that adsorption and desorption of siRNA is mainly driven by electrostatic interactions, which allow for high loading capacities even in medium-sized mesopores with pore diameters down to 4 nm in a stellate pore morphology. The negatively charged MSN shell enabled the association with a block copolymer containing positively charged artificial amino acids and oleic acid blocks, which acts simultaneously as capping and endosomal release agent. The potential of this multifunctional delivery platform is demonstrated by highly effective cell transfection and siRNA delivery into KB-cells. A luciferase reporter gene knock-down of up to 80-90% was possible using extremely low cell exposures with only 2.5 μg MSN containing 0.5 μg siRNA per 100 μL well. Electronic supplementary information (ESI) available: MSN synthesis and analysis, sample preparation for cell transfections as well as additional studies including experiments with a second cell line and a toxicity assay. See DOI: 10.1039/c5nr06246b

Different storage conditions influence biocompatibility and physicochemical properties of iron oxide nanoparticles.

PubMed

Zaloga, Jan; Janko, Christina; Agarwal, Rohit; Nowak, Johannes; Müller, Robert; Boccaccini, Aldo R; Lee, Geoffrey; Odenbach, Stefan; Lyer, Stefan; Alexiou, Christoph

2015-04-24

Superparamagnetic iron oxide nanoparticles (SPIONs) have attracted increasing attention in many biomedical fields. In magnetic drug targeting SPIONs are injected into a tumour supplying artery and accumulated inside the tumour with a magnet. The effectiveness of this therapy is thus dependent on magnetic properties, stability and biocompatibility of the particles. A good knowledge of the effect of storage conditions on those parameters is of utmost importance for the translation of the therapy concept into the clinic and for reproducibility in preclinical studies. Here, core shell SPIONs with a hybrid coating consisting of lauric acid and albumin were stored at different temperatures from 4 to 45 °C over twelve weeks and periodically tested for their physicochemical properties over time. Surprisingly, even at the highest storage temperature we did not observe denaturation of the protein or colloidal instability. However, the saturation magnetisation decreased by maximally 28.8% with clear correlation to time and storage temperature. Furthermore, the biocompatibility was clearly affected, as cellular uptake of the SPIONs into human T-lymphoma cells was crucially dependent on the storage conditions. Taken together, the results show that the particle properties undergo significant changes over time depending on the way they are stored.

The single-ion anisotropy effects in the mixed-spin ternary-alloy

NASA Astrophysics Data System (ADS)

Albayrak, Erhan

2018-04-01

The effect of single-ion anisotropy on the thermal properties of the ternary-alloy in the form of ABpC1-p is investigated on the Bethe lattice (BL) in terms of exact recursion relations. The simulation on the BL consists of placing A atoms (spin-1/2) on the odd shells and randomly placing B (spin-3/2) or C (spin-5/2) atoms with concentrations p and 1 - p, respectively, on the even shells. The phase diagrams are calculated in possible planes spanned by the system parameters: temperature, single-ion anisotropy, concentration and ratio of the bilinear interaction parameters for z = 3 corresponding to the honeycomb lattice. It is found that the crystal field drives the system to the lowest possible state therefore reducing the temperatures of the critical lines in agreement with the literature.

A detailed view of the gas shell around R Sculptoris with ALMA

NASA Astrophysics Data System (ADS)

Maercker, M.; Vlemmings, W. H. T.; Brunner, M.; De Beck, E.; Humphreys, E. M.; Kerschbaum, F.; Lindqvist, M.; Olofsson, H.; Ramstedt, S.

2016-02-01

Context. During the asymptotic giant branch (AGB) phase, stars undergo thermal pulses - short-lived phases of explosive helium burning in a shell around the stellar core. Thermal pulses lead to the formation and mixing-up of new elements to the stellar surface. They are hence fundamental to the chemical evolution of the star and its circumstellar envelope. A further consequence of thermal pulses is the formation of detached shells of gas and dust around the star, several of which have been observed around carbon-rich AGB stars. Aims: We aim to determine the physical properties of the detached gas shell around R Sculptoris, in particular the shell mass and temperature, and to constrain the evolution of the mass-loss rate during and after a thermal pulse. Methods: We analyse 12CO(1-0), 12CO(2-1), and 12CO(3-2) emission, observed with the Atacama Large Millimeter/submillimeter Array (ALMA) during Cycle 0 and complemented by single-dish observations. The spatial resolution of the ALMA data allows us to separate the detached shell emission from the extended emission inside the shell. We perform radiative transfer modelling of both components to determine the shell properties and the post-pulse mass-loss properties. Results: The ALMA data show a gas shell with a radius of 19.̋5 expanding at 14.3 km s-1. The different scales probed by the ALMA Cycle 0 array show that the shell must be entirely filled with gas, contrary to the idea of a detached shell. The comparison to single-dish spectra and radiative transfer modelling confirms this. We derive a shell mass of 4.5 × 10-3 M⊙ with a temperature of 50 K. Typical timescales for thermal pulses imply a pulse mass-loss rate of 2.3 × 10-5 M⊙ yr-1. For the post-pulse mass-loss rate, we find evidence for a gradual decline of the mass-loss rate, with an average value of 1.6 × 10-5 M⊙ yr-1. The total amount of mass lost since the last thermal pulse is 0.03 M⊙, a factor four higher compared to classical models, with a sharp decline in mass-loss rate immediately after the pulse. Conclusions: We find that the mass-loss rate after a thermal pulse has to decline more slowly than generally expected from models of thermal pulses. This may cause the star to lose significantly more mass during a thermal pulse cycle, which affects the lifetime on the AGB and the chemical evolution of the star, its circumstellar envelope, and the interstellar medium.

Neutron knockout from 68,70Ni ground and isomeric states.

NASA Astrophysics Data System (ADS)

Recchia, F.; Weisshaar, D.; Gade, A.; Tostevin, J. A.; Janssens, R. V. F.; Albers, M.; Bader, V. M.; Baugher, T.; Bazin, D.; Berryman, J. S.; Brown, B. A.; Campbell, C. M.; Carpenter, M. P.; Chen, J.; Chiara, C. J.; Crawford, H. L.; Hoffman, C. R.; Kondev, F. G.; Korichi, A.; Langer, C.; Lauritsen, T.; Liddick, S. N.; Lunderberg, E.; Noji, S.; Prokop, C.; Stroberg, S. R.; Suchyta, S.; Wimmer, K.; Zhu, S.

2018-02-01

Neutron-rich isotopes are an important source of new information on nuclear physics. Specifically, the spin-isospin components in the nucleon-nucleon (NN) interaction, e.g., the proton-neutron tensor force, are expected to modify shell structure in exotic nuclei. These potential changes in the intrinsic shell structure are of fundamental interest. The study of the excitation energy of states corresponding to specific configurations in even-even isotopes, together with the single-particle character of the first excited states of odd-A, neutron-rich Ni isotopes, probes the evolution of the neutron orbitals around the Fermi surface as a function of the neutron number a step forward in the understanding of the region and the nature of the NN interaction at large N/Z ratios. In an experiment carried out at the National Superconducting Cyclotron Laboratory [1], new spectroscopic information was obtained for 68Ni and the distribution of single-particle strengths in 67,69Ni was characterized by means of single-neutron knockout from 68,70Ni secondary beams. The spectroscopic strengths, deduced from the measured partial cross sections to the individual states tagged by their de-exciting gamma rays, is used to identify and quantify configurations that involve neutron excitations across the N = 40 harmonic oscillator shell closure. The de-excitation γ rays were measured with the GRETINA tracking array [2]. The results challenge the validity of the most current shell-model Hamiltonians and effective interactions, highlighting shortcomings that cannot yet be explained. These results suggest that our understanding of the low-energy states in such nuclei is not complete and requires further investigation.