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Sample records for nickel foams three-dimensional

  1. Design of a neutral three-dimensional electro-Fenton system with foam nickel as particle electrodes for wastewater treatment.

    PubMed

    Liu, Wei; Ai, Zhihui; Zhang, Lizhi

    2012-12-01

    In this work, we demonstrate a novel three-dimensional electro-Fenton system (3D-E-Fenton) for wastewater treatment with foam nickel, activated carbon fiber and Ti/RuO(2)-IrO(2) as the particle electrodes, the cathode, and the anode respectively. This 3D-E-Fenton system could exhibit much higher rhodamine B removal efficiency (99%) than the counterpart three-dimensional electrochemical system (33%) and E-Fenton system (19%) at neutral pH in 30 min. The degradation efficiency enhancement was attributed to much more hydroxyl radicals generated in the 3D-E-Fenton system because foam nickel particle electrodes could activate molecular oxygen to produce O(2)(-) via a single-electron transfer pathway to subsequently generate more H(2)O(2) and hydroxyl radicals. This is the first observation of molecular oxygen activation over the particle electrodes in the three-dimensional electrochemical system. These interesting findings could provide some new insight on the development of high efficient E-Fenton system for wastewater treatment at neutral pH. PMID:23141376

  2. Three dimensional nickel oxides/nickel structure by in situ electro-oxidation of nickel foam as robust electrocatalyst for oxygen evolution reaction

    NASA Astrophysics Data System (ADS)

    Han, Guan-Qun; Liu, Yan-Ru; Hu, Wen-Hui; Dong, Bin; Li, Xiao; Shang, Xiao; Chai, Yong-Ming; Liu, Yun-Qi; Liu, Chen-Guang

    2015-12-01

    Three dimensional (3D) nickel oxide/nickel (NiOx/Ni) structure has been synthesized through a facile in situ electro-oxidation method. The formation of NiOx through the electro-oxidation process has been proved by SEM and EDX, with some dense black dots appearing on the surface of Ni foam and the molar ratio of O/Ni increasing, which is nearly 7 times larger than the pure Ni foam. The increase in O content indicates the formatted black particles on the surface of Ni foam are composed of NiOx. The electrocatalytic property of the obtained 3D NiOx/Ni structure has been measured and it can be used as a highly active electrocatalyst for oxygen evolution reaction (OER). The overpotential to reach j = 10 mA cm-2 is 0.39 V. And after the long-term I-t measurement, extremely high electrochemical and physical stability are exhibited in the 3D structure, keeping electrochemical activity and morphology the same. The excellent OER properties may be attributed to the 3D structure and the interface effect of NiOx/Ni.

  3. Synthesis of three dimensional nickel cobalt oxide nanoneedles on nickel foam, their characterization and glucose sensing application.

    PubMed

    Hussain, Mushtaque; Ibupoto, Zafar Hussain; Abbasi, Mazhar Ali; Liu, Xianjie; Nur, Omer; Willander, Magnus

    2014-01-01

    In the present work, NiCo2O4 nanostructures are fabricated in three dimensions (3D) on nickel foam by the hydrothermal method. The nanomaterial was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The nanostructures exhibit nanoneedle-like morphology grown in 3D with good crystalline quality. The nanomaterial is composed of nickel, cobalt and oxygen atoms. By using the favorable porosity of the nanomaterial and the substrate itself, a sensitive glucose sensor is proposed by immobilizing glucose oxidase. The presented glucose sensor has shown linear response over a wide range of glucose concentrations from 0.005 mM to 15 mM with a sensitivity of 91.34 mV/decade and a fast response time of less than 10 s. The NiCo2O4 nanostructures-based glucose sensor has shown excellent reproducibility, repeatability and stability. The sensor showed negligible response to the normal concentrations of common interferents with glucose sensing, including uric acid, dopamine and ascorbic acid. All these favorable advantages of the fabricated glucose sensor suggest that it may have high potential for the determination of glucose in biological samples, food and other related areas. PMID:24647124

  4. Synthesis of Three Dimensional Nickel Cobalt Oxide Nanoneedles on Nickel Foam, Their Characterization and Glucose Sensing Application

    PubMed Central

    Hussain, Mushtaque; Ibupoto, Zafar Hussain; Abbasi, Mazhar Ali; Liu, Xianjie; Nur, Omer; Willander, Magnus

    2014-01-01

    In the present work, NiCo2O4 nanostructures are fabricated in three dimensions (3D) on nickel foam by the hydrothermal method. The nanomaterial was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The nanostructures exhibit nanoneedle-like morphology grown in 3D with good crystalline quality. The nanomaterial is composed of nickel, cobalt and oxygen atoms. By using the favorable porosity of the nanomaterial and the substrate itself, a sensitive glucose sensor is proposed by immobilizing glucose oxidase. The presented glucose sensor has shown linear response over a wide range of glucose concentrations from 0.005 mM to 15 mM with a sensitivity of 91.34 mV/decade and a fast response time of less than 10 s. The NiCo2O4 nanostructures-based glucose sensor has shown excellent reproducibility, repeatability and stability. The sensor showed negligible response to the normal concentrations of common interferents with glucose sensing, including uric acid, dopamine and ascorbic acid. All these favorable advantages of the fabricated glucose sensor suggest that it may have high potential for the determination of glucose in biological samples, food and other related areas. PMID:24647124

  5. Improved wetting behavior and thermal conductivity of the three-dimensional nickel foam/epoxy composites with graphene oxide as interfacial modifier

    NASA Astrophysics Data System (ADS)

    Huang, Liang; Zhu, Pengli; Li, Gang; Sun, Rong

    2016-05-01

    The partial reduced graphene oxide (P-rGO) sheets-wrapped nickel foams (NF@P-rGO) were prepared by hydrothermal method, and then their epoxy composites were fabricated via a simple drop-wetting process. The P-rGO sheets on the metal networks could effectively improve the compatibility between nickel foam and epoxy resin, thus greatly accelerate the wetting of epoxy resin on the foams and avoid cracks in the network-polymer interface. Owing to the existence of high-efficiency conductive metal networks, the NF@P-rGO/epoxy composite has a high thermal conductivity of 0.584 W m-1 K-1, which is 2.6 times higher than that of neat epoxy resin. Additionally, owing to the improved wetting ability, NF@P-rGO-10 wt% boron nitride (BN) microsheets/epoxy composites could be fabricated and have a further higher thermal conductivity of 0.71 W m-1 K-1. We believe the use of P-rGO as a novel surface modifier and the following liquid polymer drop-wetting could be an effective method to obtain novel and outstanding metal foam/polymer composites.

  6. Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance

    SciTech Connect

    Zhang, Shuna; Zhang, Shujuan; Song, Limin; Wu, Xiaoqing; Fang, Sheng

    2014-05-01

    Graphical abstract: Three-dimensional interconnected nickel phosphide networks with hollow microstructures and desulfurization performance. - Highlights: • Three-dimensional Ni{sub 2}P has been prepared using foam nickel as a template. • The microstructures interconnected and formed sponge-like porous networks. • Three-dimensional Ni{sub 2}P shows superior hydrodesulfurization activity. - Abstract: Three-dimensional microstructured nickel phosphide (Ni{sub 2}P) was fabricated by the reaction between foam nickel (Ni) and phosphorus red. The as-prepared Ni{sub 2}P samples, as interconnected networks, maintained the original mesh structure of foamed nickel. The crystal structure and morphology of the as-synthesized Ni{sub 2}P were characterized by X-ray diffraction, scanning electron microscopy, automatic mercury porosimetry and X-ray photoelectron spectroscopy. The SEM study showed adjacent hollow branches were mutually interconnected to form sponge-like networks. The investigation on pore structure provided detailed information for the hollow microstructures. The growth mechanism for the three-dimensionally structured Ni{sub 2}P was postulated and discussed in detail. To investigate its catalytic properties, SiO{sub 2} supported three-dimensional Ni{sub 2}P was prepared successfully and evaluated for the hydrodesulfurization (HDS) of dibenzothiophene (DBT). DBT molecules were mostly hydrogenated and then desulfurized by Ni{sub 2}P/SiO{sub 2}.

  7. Three-dimensional nanostructured Ni-Cu foams for borohydride oxidation

    NASA Astrophysics Data System (ADS)

    Santos, D. M. F.; Eugénio, S.; Cardoso, D. S. P.; Šljukić, B.; Montemor, M. F.

    2015-12-01

    Three-dimensional (3D) nanostructured nickel-copper (Ni-Cu) foams have been prepared by electrodeposition using a dynamic hydrogen template. These 3D materials were tested as electrodes for the borohydride oxidation reaction (BOR) in alkaline media for possible application as anodes of direct borohydride fuel cells. Their activity in BOR was studied using cyclic voltammetry, chronoamperometry, and chronopotentiometry and main reaction parameters and electrodes' stability were evaluated.

  8. Design, synthesis and evaluation of three-dimensional Co3O4/Co3(VO4)2 hybrid nanorods on nickel foam as self-supported electrodes for asymmetric supercapacitors

    NASA Astrophysics Data System (ADS)

    Zhang, Wei-Bin; Kong, Ling-Bin; Ma, Xue-Jing; Luo, Yong-Chun; Kang, Long

    2014-12-01

    A novel self-supported electrode of three-dimensional Co3O4/Co3(VO4)2 hybrid nanorods on the conductive substrate of nickel foam have been designed and synthesized by the combination of hydrothermal synthesis and subsequent annealing treatment. Based on the morphology, a possible mechanism is proposed. The unique nanostructure has been served as an "ion reservoir" to infiltrate between the electrode surface area and the electrolyte, which can ensure the ion/electron transfer. And the powerful distribution of electric field on nanorods makes the surface in response the electrode reaction as completely as possible. The electrode manifests satisfying capacitance of 847.2 F g-1, outstanding rate capability and excellent cycling stability. Also, an asymmetric supercapacitor has been assembled, where Co3O4/Co3(VO4)2 and activated carbon acted as the positive and negative electrodes respectively, and the maximum specific capacitance of 105 F g-1 and the specific energy of 38 Wh kg-1 are demonstrated at a cell voltage between 0 and 1.6 V, exhibiting a high energy density and stable power characteristic.

  9. Ultralight three-dimensional boron nitride foam with ultralow permittivity and superelasticity.

    PubMed

    Yin, Jun; Li, Xuemei; Zhou, Jianxin; Guo, Wanlin

    2013-07-10

    Dielectrics with ultralow permittivity within 2 times that of air, excellent mechanical performance, and high thermal stability are highly attractive to many applications. However, since the finding of silica aerogels in the 1930s, no alternative ultralight porous dielectric with density below 10 mg/cm(3) has been developed. Here we present three-dimensional hierarchical boron nitride foam with permittivity of 1.03 times that of air, density of 1.6 mg/cm(3), and thermal stability up to 1200 °C obtained by chemical vapor deposition on a nickel foam template. This BN foam exhibits complete recovery after cyclic compression exceeding 70% with permittivity within 1.12 times that of air. Gathering all these exceptional characters, the BN foam should create a breakthrough development of flexible ultralow-permittivity dielectrics and ultralight materials. PMID:23799859

  10. Fabrication of three-dimensional graphene foam with high electrical conductivity and large adsorption capability

    NASA Astrophysics Data System (ADS)

    Chen, Guiqiang; Liu, Yanxia; Liu, Fei; Zhang, Xiao

    2014-08-01

    A three-dimensional (3D), free-standing graphene foam was prepared by plasma-enhanced chemical vapor deposition on nickel-foam. The prepared graphene foam was found to consist of few-layered vertically-aligned graphene sheets with highly graphite structure. Owing to the 3D interconnected porous nanostructures, the graphene foam exhibited a high electrical conductivity of 125 S/cm and a large surface area of 625.4 cm2/g. For practical application, we prepared the graphene foam/epoxy composites showing a maximum conductivity of 196 S/m at 2.5 vol.% filler loading, and a rather low percolation threshold of 0.18 vol.%. Furthermore, the derived graphene oxide foam exhibited an excellent absorption capability (177.6 mg/g for As(V), 399.3 mg/g for Pb(II)) and recyclability (above 90% removal efficiency after five cycles) for the removal of heavy metal ions. The present study reveals that the multifunctional graphene foam may broaden the graphene-based materials for the applications in electrically conductive composites and environmental cleanup.

  11. An Accurate von Neumann's Law for Three-Dimensional Foams

    SciTech Connect

    Hilgenfeldt, Sascha; Kraynik, Andrew M.; Koehler, Stephan A.; Stone, Howard A.

    2001-03-19

    The diffusive coarsening of 2D soap froths is governed by von Neumann's law. A statistical version of this law for dry 3D foams has long been conjectured. A new derivation, based on a theorem by Minkowski, yields an explicit analytical von Neumann's law in 3D which is in very good agreement with detailed simulations and experiments. The average growth rate of a bubble with F faces is shown to be proportional to F{sup 1/2} for large F , in contrast to the conjectured linear dependence. Accounting for foam disorder in the model further improves the agreement with data.

  12. Enhancement of direct urea-hydrogen peroxide fuel cell performance by three-dimensional porous nickel-cobalt anode

    NASA Astrophysics Data System (ADS)

    Guo, Fen; Cao, Dianxue; Du, Mengmeng; Ye, Ke; Wang, Guiling; Zhang, Wenping; Gao, Yinyi; Cheng, Kui

    2016-03-01

    A novel three-dimensional (3D) porous nickel-cobalt (Ni-Co) film on nickel foam is successfully prepared and further used as an efficient anode for direct urea-hydrogen peroxide fuel cell (DUHPFC). By varying the cobalt/nickel mole ratios into 0%, 20%, 50%, 80% and 100%, the optimized Ni-Co/Ni foam anode with a ratio of 80% is obtained in terms of the best cell performance among five anodes. Effects of the KOH and urea concentrations, the flow rate and operation temperature on the fuel cell performance are investigated. Results show DUHPFC with the 3D Ni-Co/Ni foam anode exhibits a higher performance than those reported direct urea fuel cells. The cell gives an open circuit voltage of 0.83 V and a peak power density as high as 17.4 and 31.5 mW cm-2 at 20 °C and 70 °C, respectively, when operating on 7.0 mol L-1 KOH and 0.5 mol L-1 urea as the fuel at a flow rate of 15 mL min-1. Besides, when the human urine is directly fed as the fuel, direct urine-hydrogen peroxide fuel cell reaches a maximum power density of 7.5 mW cm-2 with an open circuit voltage of 0.80 V at 20 °C, showing a good application prospect in wastewater treatment.

  13. Three-dimensional graphene foam as a biocompatible and conductive scaffold for neural stem cells

    NASA Astrophysics Data System (ADS)

    Li, Ning; Zhang, Qi; Gao, Song; Song, Qin; Huang, Rong; Wang, Long; Liu, Liwei; Dai, Jianwu; Tang, Mingliang; Cheng, Guosheng

    2013-04-01

    Neural stem cell (NSC) based therapy provides a promising approach for neural regeneration. For the success of NSC clinical application, a scaffold is required to provide three-dimensional (3D) cell growth microenvironments and appropriate synergistic cell guidance cues. Here, we report the first utilization of graphene foam, a 3D porous structure, as a novel scaffold for NSCs in vitro. It was found that three-dimensional graphene foams (3D-GFs) can not only support NSC growth, but also keep cell at an active proliferation state with upregulation of Ki67 expression than that of two-dimensional graphene films. Meanwhile, phenotypic analysis indicated that 3D-GFs can enhance the NSC differentiation towards astrocytes and especially neurons. Furthermore, a good electrical coupling of 3D-GFs with differentiated NSCs for efficient electrical stimulation was observed. Our findings implicate 3D-GFs could offer a powerful platform for NSC research, neural tissue engineering and neural prostheses.

  14. Green Synthesis of Porous Three-Dimensional Nitrogen-Doped Graphene Foam for Electrochemical Applications.

    PubMed

    Yu, Hua; Ye, Delai; Butburee, Teera; Wang, Lianzhou; Dargusch, Matthew

    2016-02-01

    A facile and green approach was developed for the production of porous three-dimensional (3D) nitrogen-doped graphene with a foam structure. In comparison with conventional methods, this green approach uses environmental precursors in the preparation of graphene products. The resulting crystalline graphene foam product exhibited a uniform structure with large surface area. These appealing features render the prepared graphene foam product a prospective backbone for producing 3D charge-transport networks. The 3D graphene foam products were employed as the skeleton with an interconnected network for lithium-ion batteries. The lithium-ion batteries with the 3D porous foam structure exhibit superior cycling stability and good rate capability. There is no capacity loss after 800 cycles because the capacity stabilized for the first few cycles, and the lithium-ion batteries with 3D graphene foam showed a discharge capacity of 180 mA h g(-1) at a current density of 1000 mA g(-1). This superior cycling stability and good rate capability was ascribed to the 3D structure with an interconnected porous network and the nitrogen-doping strategy for improved conductive properties of graphene foam, which produces an efficient 3D charge-transport network. The configuration of this 3D transport network in lithium-ion cells not only can improve the electron-transport efficiency but also can suppress the volume effect during charge/discharge cycling. Besides, nitrogen doping could enhance the formation of chemical bonding between carbon and the nearby nitrogen atoms, which could accelerate the diffusion of lithium ions through the whole graphene network. PMID:26744920

  15. Weight and crash optimization of foam-filled three-dimensional ``S'' frame

    NASA Astrophysics Data System (ADS)

    Kim, H.-S.; Chen, W.; Wierzbicki, T.

    The optimization process with the target of minimum weight design of a foam-filled three-dimensional thin-walled S frame under the prescribed values of stiffness and energy absorption was formulated and solved. A distinctive feature of the present approach is that the response function is given as an analytical expression. Three design parameters were introduced in this study, which are the width of the column wall, gauge thickness, and the relative foam density. The sequential quadratic programming (SQP) was employed to find the optimum design variables and the necessary calculation can be completed within a few minutes. Comparing with the optimized empty S frames, about 75% increase in the specific energy absorption was achieved for the aluminum foam-filled S frames. All the analytical solution and the optimization results were verified with the confirmation runs made by commercial FE code PAM-CRASH. The error was within 6%. It was observed that least weight is achieved with a low relative foam density (of an order of 5%) and a thin gauge outer shell. Also, the cross-sectional dimensions b×b are realistic from the packaging point of view (for example, 90 mm × 90 mm). The present methodology can be used as a valuable tool in the early stage of crash-oriented car body design.

  16. Facile fabrication of three-dimensional graphene foam/poly(dimethylsiloxane) composites and their potential application as strain sensor.

    PubMed

    Xu, Rongqing; Lu, Yunqing; Jiang, Chunhui; Chen, Jing; Mao, Peng; Gao, Guanghua; Zhang, Labao; Wu, Shan

    2014-08-27

    A three-dimensional (3D) graphene foam (GF)/poly(dimethylsiloxane) (PDMS) composite was fabricated by infiltrating PDMS into 3D GF, which was synthesized by chemical vapor deposition (CVD) with nickel foam as template. The electrical properties of the GF/PDMS composite under bending stress were investigated, indicating the resistance of the GF/PDMS composite was increased with the bending curvature. To improve the bending sensitivity of the GF/PDMS composite, a thin layer of poly(ethylene terephthalate) (PET) was introduced as substrate to form double-layer GF/PDMS-PET composite, whose measurements showed that the resistance of the GF/PDMS-PET composite was still increased when bended to the side of PET, whereas its resistance would be decreased when bended to the side of GF. For both cases, the absolute value of the relative variation of electrical resistance was increased with the bending curvature. More importantly, the relative variation of electrical resistance for double-layer GF/PDMS-PET composite can be up to six times higher than single-layer GF/PDMS composite for the same bending curvature. These observations were further supported by the principle of mechanics of material. The 3D GF/PDMS-PET composite also has higher flexibility and environment stability and can be utilized as a strain sensor with high sensitivity, which can find important applications in real-time monitoring of buildings, such as a bridge, dam, and high-speed railway. PMID:25070179

  17. Facile synthesis of nickel network supported three-dimensional graphene gel as a lightweight and binder-free electrode for high rate performance supercapacitor application.

    PubMed

    Huang, Haifu; Xu, Lianqiang; Tang, Yanmei; Tang, Shaolong; Du, Youwei

    2014-02-21

    Here we report a simple strategy to prepare three-dimensional graphene gel coated on nickel foam for supercapacitor applications by a simple 'dipping and drying' process. The supercapacitors based on three-dimensional graphene gel (G-gel@NF-1) exhibited high rate capability of 152 F g(-1) at 0.36 A g(-1) and 107 F g(-1) at 90.9 A g(-1), good cycle stability with capacitance retention of 89% after 2000 cycles and low internal resistance (0.58 Ω). Furthermore, a flexible electrode (G-gel@NF-2) was obtained by etching most of the nickel foam but maintains the conductive backbone of the nickel foam, which greatly reduces the total mass of the electrode (can be reduced from 30 mg cm(-2) to less than 5 mg cm(-2)), and can be compressed from a thickness of 1 mm to ∼30 μm. With the aid of a conductive network composed of a small amount of nickel, G-gel@NF-2 still has good performance in high rate capability and displays excellent flexible properties. The specific capacitance when the mass density of the electrode was only 5.4 mg cm(-2) still reached ∼115 F g(-1). This strategy can improve the rate capability performance, greatly reduce the mass of the electrode, and lower the fabrication cost of supercapacitors. PMID:24441914

  18. Three-dimensional graphene foam as a biocompatible and conductive scaffold for neural stem cells

    PubMed Central

    Li, Ning; Zhang, Qi; Gao, Song; Song, Qin; Huang, Rong; Wang, Long; Liu, Liwei; Dai, Jianwu; Tang, Mingliang; Cheng, Guosheng

    2013-01-01

    Neural stem cell (NSC) based therapy provides a promising approach for neural regeneration. For the success of NSC clinical application, a scaffold is required to provide three-dimensional (3D) cell growth microenvironments and appropriate synergistic cell guidance cues. Here, we report the first utilization of graphene foam, a 3D porous structure, as a novel scaffold for NSCs in vitro. It was found that three-dimensional graphene foams (3D-GFs) can not only support NSC growth, but also keep cell at an active proliferation state with upregulation of Ki67 expression than that of two-dimensional graphene films. Meanwhile, phenotypic analysis indicated that 3D-GFs can enhance the NSC differentiation towards astrocytes and especially neurons. Furthermore, a good electrical coupling of 3D-GFs with differentiated NSCs for efficient electrical stimulation was observed. Our findings implicate 3D-GFs could offer a powerful platform for NSC research, neural tissue engineering and neural prostheses. PMID:23549373

  19. A Novel Role of Three Dimensional Graphene Foam to Prevent Heater Failure during Boiling

    PubMed Central

    Ahn, Ho Seon; Kim, Ji Min; Park, Chibeom; Jang, Ji-Wook; Lee, Jae Sung; Kim, Hyungdae; Kaviany, Massoud; Kim, Moo Hwan

    2013-01-01

    We report a novel boiling heat transfer (NBHT) in reduced graphene oxide (RGO) suspended in water (RGO colloid) near critical heat flux (CHF), which is traditionally the dangerous limitation of nucleate boiling heat transfer because of heater failure. When the heat flux reaches the maximum value (CHF) in RGO colloid pool boiling, the wall temperature increases gradually and slowly with an almost constant heat flux, contrary to the rapid wall temperature increase found during water pool boiling. The gained time by NBHT would provide the safer margin of the heat transfer and the amazing impact on the thermal system as the first report of graphene application. In addition, the CHF and boiling heat transfer performance also increase. This novel boiling phenomenon can effectively prevent heater failure because of the role played by the self-assembled three-dimensional foam-like graphene network (SFG). PMID:23743619

  20. A novel role of three dimensional graphene foam to prevent heater failure during boiling.

    PubMed

    Ahn, Ho Seon; Kim, Ji Min; Park, Chibeom; Jang, Ji-Wook; Lee, Jae Sung; Kim, Hyungdae; Kaviany, Massoud; Kim, Moo Hwan

    2013-01-01

    We report a novel boiling heat transfer (NBHT) in reduced graphene oxide (RGO) suspended in water (RGO colloid) near critical heat flux (CHF), which is traditionally the dangerous limitation of nucleate boiling heat transfer because of heater failure. When the heat flux reaches the maximum value (CHF) in RGO colloid pool boiling, the wall temperature increases gradually and slowly with an almost constant heat flux, contrary to the rapid wall temperature increase found during water pool boiling. The gained time by NBHT would provide the safer margin of the heat transfer and the amazing impact on the thermal system as the first report of graphene application. In addition, the CHF and boiling heat transfer performance also increase. This novel boiling phenomenon can effectively prevent heater failure because of the role played by the self-assembled three-dimensional foam-like graphene network (SFG). PMID:23743619

  1. Scalable Seashell-Based Chemical Vapor Deposition Growth of Three-Dimensional Graphene Foams for Oil-Water Separation.

    PubMed

    Shi, Liurong; Chen, Ke; Du, Ran; Bachmatiuk, Alicja; Rümmeli, Mark Hermann; Xie, Kongwei; Huang, Youyuan; Zhang, Yanfeng; Liu, Zhongfan

    2016-05-25

    A seashell-based CVD technique for preparing three-dimensional (3D) graphene foams is reported. The graphene sheets in thus-obtained foams are seamlessly interconnected into a 3D flexible network, forming highly porous materials with negligible non-carbon impurities, ultralow density, and outstanding mechanical flexibility and electrical conductivity. These 3D graphene foams demonstrate a fast adsorption performance toward various oils and organic solvents, with adsorption capacity up to 250-fold weight gain. The present approach offers a practical route for scalable construction of 3D graphene foams for versatile applications such as energy storage and water remediation. PMID:27157548

  2. Ultrathin Graphite Foam: A Three-Dimensional Conductive Network for Battery Electrodes

    SciTech Connect

    Ji, HX; Zhang, LL; Pettes, MT; Li, HF; Chen, SS; Shi, L; Piner, R; Ruoff, RS

    2012-05-01

    We report the use of free-standing, lightweight, and highly conductive ultrathin graphite foam (UGF), loaded with lithium iron phosphate (LFP), as a cathode in a lithium ion battery. At a high charge/discharge current density of 1280 mA g(-1), the specific capacity of the LFP loaded on UGF was 70 mAh g(-1), while LFP loaded on Al foil failed. Accounting for the total mass of the electrode, the maximum specific capacity of the UGF/LFP cathode was 23% higher than that of the Al/LFP cathode and 170% higher than that of the Ni-foam/LFP cathode. Using UGF, both a higher rate capability and specific capacity can be achieved simultaneously, owing to its conductive (similar to 1.3 x 10(5) S m(-1) at room temperature) and three-dimensional lightweight (similar to 9.5 mg cm(-3)) graphitic structure. Meanwhile, UGF presents excellent electrochemical stability comparing to that of Al and Ni foils, which are generally used as conductive substrates in lithium ion batteries. Moreover, preparation of the UGF electrode was facile, cost-effective, and compatible with various electrochemically active materials.

  3. Electrodeposition of hierarchically structured three-dimensional nickel-iron electrodes for efficient oxygen evolution at high current densities

    NASA Astrophysics Data System (ADS)

    Lu, Xunyu; Zhao, Chuan

    2015-03-01

    Large-scale industrial application of electrolytic splitting of water has called for the development of oxygen evolution electrodes that are inexpensive, robust and can deliver large current density (>500 mA cm-2) at low applied potentials. Here we show that an efficient oxygen electrode can be developed by electrodepositing amorphous mesoporous nickel-iron composite nanosheets directly onto macroporous nickel foam substrates. The as-prepared oxygen electrode exhibits high catalytic activity towards water oxidation in alkaline solutions, which only requires an overpotential of 200 mV to initiate the reaction, and is capable of delivering current densities of 500 and 1,000 mA cm-2 at overpotentials of 240 and 270 mV, respectively. The electrode also shows prolonged stability against bulk water electrolysis at large current. Collectively, the as-prepared three-dimensional structured electrode is the most efficient oxygen evolution electrode in alkaline electrolytes reported to the best of our knowledge, and can potentially be applied for industrial scale water electrolysis.

  4. Electrodeposition of hierarchically structured three-dimensional nickel-iron electrodes for efficient oxygen evolution at high current densities.

    PubMed

    Lu, Xunyu; Zhao, Chuan

    2015-01-01

    Large-scale industrial application of electrolytic splitting of water has called for the development of oxygen evolution electrodes that are inexpensive, robust and can deliver large current density (>500 mA cm(-2)) at low applied potentials. Here we show that an efficient oxygen electrode can be developed by electrodepositing amorphous mesoporous nickel-iron composite nanosheets directly onto macroporous nickel foam substrates. The as-prepared oxygen electrode exhibits high catalytic activity towards water oxidation in alkaline solutions, which only requires an overpotential of 200 mV to initiate the reaction, and is capable of delivering current densities of 500 and 1,000 mA cm(-2) at overpotentials of 240 and 270 mV, respectively. The electrode also shows prolonged stability against bulk water electrolysis at large current. Collectively, the as-prepared three-dimensional structured electrode is the most efficient oxygen evolution electrode in alkaline electrolytes reported to the best of our knowledge, and can potentially be applied for industrial scale water electrolysis. PMID:25776015

  5. Highly Stretchable and Sensitive Strain Sensor Based on Facilely Prepared Three-Dimensional Graphene Foam Composite.

    PubMed

    Li, Jinhui; Zhao, Songfang; Zeng, Xiaoliang; Huang, Wangping; Gong, Zhengyu; Zhang, Guoping; Sun, Rong; Wong, Ching-Ping

    2016-07-27

    Wearable strain sensors with excellent stretchability and sensitivity have emerged as a very promising field which could be used for human motion detection and biomechanical systems, etc. Three-dimensional (3D) graphene foam (GF) has been reported before for high-performance strain sensors, however, some problems such as high cost preparation, low sensitivity, and stretchability still remain. In this paper, we report a highly stretchable and sensitive strain sensor based on 3D GF and polydimethylsiloxane (PDMS) composite. The GF is prepared by assembly process from graphene oxide via a facile and scalable method and possesses excellent mechanical property which facilitates the infiltration of PDMS prepolymer into the graphene framework. The as-prepared strain sensor can be stretched as high as 30% of its original length and the gauge factor of this sensor is as high as 98.66 under 5% of applied strain. Moreover, the strain sensor shows long-term stability in 200 cycles of stretching-relaxing. Implementation of the device for monitoring the bending of elbow and finger results in reproducibility and various responses in the form of resistance change. Thus, the developed strain sensors exhibit great application potential in fields of biomechanical systems and human-interactive applications. PMID:27384320

  6. Chiral Three-Dimensional Microporous Nickel Aspartate with Extended Ni-O-Ni Bonding

    SciTech Connect

    Anokhina,E.; Go, Y.; Lee, Y.; Vogt, T.; Jacobson, A.

    2006-01-01

    In the course of our investigation aimed at the preparation of homochiral coordination polymers using readily available in optically pure form ligands and building blocks of condensed metal polyhedra, we recently reported a one-dimensional nickel aspartate compound [Ni{sub 2}O(L-Asp)(H{sub 2}O){sub 2}]{center_dot}4H{sub 2}O (1) based on helical chains with extended Ni-O-Ni bonding. Here we report a new nickel aspartate [Ni{sub 2.5}(OH)(L-Asp){sub 2}]{center_dot}6.55H{sub 2}O (2) with a three-dimensional Ni-O-Ni connectivity that forms at a higher pH and is based on the same helices as in 1 which are connected by additional nickel octahedra to generate a chiral open framework with one-dimensional channels with minimum van der Waals dimensions of 8 x 5 Angstroms. The crystal structure of 2 was determined by synchrotron single-crystal X-ray diffraction on a 10 x 10 x 240 {micro}m crystal.

  7. Highly sensitive and selective nonenzymatic detection of glucose using three-dimensional porous nickel nanostructures.

    PubMed

    Niu, Xiangheng; Lan, Minbo; Zhao, Hongli; Chen, Chen

    2013-04-01

    Highly sensitive and selective nonenzymatic detection of glucose has been achieved using a novel disposable electrochemical sensor based on three-dimensional (3D) porous nickel nanostructures. The enzyme-free sensor was fabricated through in situ growing porous nickel networks on a homemade screen-printed carbon electrode substrate via electrochemically reducing the Ni(2+) precursor, along with continuously liberating hydrogen bubbles. The resulting nickel-modified electrode was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectrometry (EDX), powder X-ray diffractometry (XRD), and electrochemical techniques. Cyclic voltammetric, alternating-current impedance, and amperometric methods were used to investigate the catalytic properties of the assembled sensor for glucose electro-oxidation in alkaline media. Under optimized conditions, the enzymeless sensor exhibited excellent performance for glucose analysis selectively, offering a much wider linear range (from 0.5 μM to 4 mM), an extremely low detection limit (0.07 μM, signal-to-noise ratio (S/N) of 3), and an ultrahigh sensitivity of 2.9 mA/(cm(2) mM). Importantly, favorable reproducibility and long-term performance stability were obtained thanks to the robust frameworks. Application of the proposed sensor in monitoring blood glucose was also demonstrated. PMID:23458297

  8. Manufacturing three-dimensional nickel titanium articles using layer-by-layer laser-melting technology

    NASA Astrophysics Data System (ADS)

    Shishkovsky, I. V.; Yadroitsev, I. A.; Smurov, I. Yu.

    2013-12-01

    Specific features of layer-by-layer synthesis of three-dimensional (3D) nickel titanium (NiTi, nitinol) articles by selective laser melting (SLM) technology have been studied. Nonporous 3D nitinol articles have been obtained for the first time in a single technological cycle. A necessary condition was that the NiTi powder medium was heated to 500°C during sintering. The structure and composition of intermetallic phases in SLM-synthesized samples have been studied by optical metallography, microhardness measurements, scanning electron microscopy, X-ray diffraction, and energy-dispersive x-ray analysis techniques. Optimum SLM regimes for manufacturing NiTi articles and promising medical applications of this material are considered.

  9. Three-dimensional mapping of nickel oxidation states using full field x-ray absorption near edge structure nanotomography

    SciTech Connect

    Nelson, George J.; Harris, William M.; Izzo, John R. Jr.; Grew, Kyle N.; Chiu, Wilson K. S.; Chu, Yong S.; Yi, Jaemock; Andrews, Joy C.; Liu Yijin; Pianetta, Piero

    2011-04-25

    The reduction-oxidation cycling of the nickel-based oxides in composite solid oxide fuel cells and battery electrodes is directly related to cell performance. A greater understanding of nickel redox mechanisms at the microstructural level can be achieved in part using transmission x-ray microscopy (TXM) to explore material oxidation states. X-ray nanotomography combined with x-ray absorption near edge structure (XANES) spectroscopy has been applied to study samples containing distinct regions of nickel and nickel oxide (NiO) compositions. Digitally processed images obtained using TXM demonstrate the three-dimensional chemical mapping and microstructural distribution capabilities of full-field XANES nanotomography.

  10. Three-dimensional mapping of nickel oxidation states using full field x-ray absorption near edge structure nanotomography

    NASA Astrophysics Data System (ADS)

    Nelson, George J.; Harris, William M.; Izzo, John R.; Grew, Kyle N.; Chiu, Wilson K. S.; Chu, Yong S.; Yi, Jaemock; Andrews, Joy C.; Liu, Yijin; Pianetta, Piero

    2011-04-01

    The reduction-oxidation cycling of the nickel-based oxides in composite solid oxide fuel cells and battery electrodes is directly related to cell performance. A greater understanding of nickel redox mechanisms at the microstructural level can be achieved in part using transmission x-ray microscopy (TXM) to explore material oxidation states. X-ray nanotomography combined with x-ray absorption near edge structure (XANES) spectroscopy has been applied to study samples containing distinct regions of nickel and nickel oxide (NiO) compositions. Digitally processed images obtained using TXM demonstrate the three-dimensional chemical mapping and microstructural distribution capabilities of full-field XANES nanotomography.

  11. Cobalt oxide nanosheets wrapped onto nickel foam for non-enzymatic detection of glucose.

    PubMed

    Meng, Shangjun; Wu, Meiyan; Wang, Qian; Dai, Ziyang; Si, Weili; Huang, Wei; Dong, Xiaochen

    2016-08-26

    Ultra-sensitive and highly selective detection of glucose is essential for the clinical diagnosis of diabetes. In this paper, an ultra-sensitive glucose sensor was successfully fabricated based on cobalt oxide (Co3O4) nanosheets directly grown on nickel foam through a simple hydrothermal method. Characterizations indicated that the Co3O4 nanosheets are completely and uniformly wrapped onto the surface of nickel foam to form a three-dimensional heterostructure. The resulting self-standing electrochemical electrode presents a high performance for the non-enzymatic detection of glucose, including short response time (<10 s), ultra-sensitivity (12.97 mA mM(-1) cm(-2)), excellent selectivity and low detection limit (0.058 μM, S/N = 3). These results indicate that Co3O4 nanosheets wrapped onto nickel foam are a low-cost, practical, and high performance electrochemical electrode for bio sensing. PMID:27407035

  12. Cobalt oxide nanosheets wrapped onto nickel foam for non-enzymatic detection of glucose

    NASA Astrophysics Data System (ADS)

    Meng, Shangjun; Wu, Meiyan; Wang, Qian; Dai, Ziyang; Si, Weili; Huang, Wei; Dong, Xiaochen

    2016-08-01

    Ultra-sensitive and highly selective detection of glucose is essential for the clinical diagnosis of diabetes. In this paper, an ultra-sensitive glucose sensor was successfully fabricated based on cobalt oxide (Co3O4) nanosheets directly grown on nickel foam through a simple hydrothermal method. Characterizations indicated that the Co3O4 nanosheets are completely and uniformly wrapped onto the surface of nickel foam to form a three-dimensional heterostructure. The resulting self-standing electrochemical electrode presents a high performance for the non-enzymatic detection of glucose, including short response time (<10 s), ultra-sensitivity (12.97 mA mM‑1 cm‑2), excellent selectivity and low detection limit (0.058 μM, S/N = 3). These results indicate that Co3O4 nanosheets wrapped onto nickel foam are a low-cost, practical, and high performance electrochemical electrode for bio sensing.

  13. Ni foam: a novel three-dimensional porous sensing platform for sensitive and selective nonenzymatic glucose detection.

    PubMed

    Lu, Wenbo; Qin, Xiaoyun; Asiri, Abdullah M; Al-Youbi, Abdulrahman O; Sun, Xuping

    2013-01-21

    The present communication reports on the first use of commercially available three-dimensional porous Ni foam (NF) as a novel electrochemical sensing platform for nonenzymatic glucose detection. NF not only acts as a working electrode, but also functions as an effective electrocatalyst for electrooxidation of glucose. The sensor exhibits high selectivity toward glucose. The linear range and limit of detection were 0.05-7.35 mM (R = 0.995) and 2.2 μM with a signal-to-noise ratio of 3, respectively. The application of this glucose sensor in human blood serum has also been demonstrated successfully. PMID:23162811

  14. An innovative three-dimensional gelatin foam culture system for improved study of glioblastoma stem cell behavior.

    PubMed

    Yang, Meng-Yin; Chiao, Ming-Tsang; Lee, Hsu-Tung; Chen, Chien-Min; Yang, Yi-Chin; Shen, Chiung-Chyi; Ma, Hsin-I

    2015-04-01

    Three-dimensional (3-D) tissue engineered constructs provide a platform for examining how the local extracellular matrix contributes to the malignancy of various cancers, including human glioblastoma multiforme. Here, we describe a simple and innovative 3-D culture environment and assess its potential for use with glioblastoma stem cells (GSCs) to examine the diversification inside the cell mass in the 3-D culture system. The dissociated human GSCs were cultured using gelatin foam. These cells were subsequently identified by immunohistochemical staining, reverse transcriptase-polymerase chain reaction, and Western blot assay. We demonstrate that the gelatin foam provides a suitable microenvironment, as a 3-D culture system, for GSCs to maintain their stemness. The gelatin foam culture system contributes a simplified assessment of cell blocks for immunohistochemistry assay. We show that the significant transcription activity of hypoxia and the protein expression of inflammatory responses are detected at the inside of the cell mass in vitro, while robust expression of PROM1/CD133 and hypoxia-induced factor-1 alpha are detected at the xenografted tumor in vivo. We also examine the common clinical trials under this culture platform and characterized a significant difference of drug resistance. The 3-D gelatin foam culture system can provide a more realistic microenvironment through which to study the in vivo behavior of GSCs to evaluate the role that biophysical factors play in the hypoxia, inflammatory responses and subsequent drug resistance. PMID:24966152

  15. A non-linear von Neumann law for three-dimensional foam coarsening

    NASA Astrophysics Data System (ADS)

    Hilgenfeldt, Sascha; Kraynik, Andrew M.; Koehler, Stephan A.; Stone, Howard A.

    2001-03-01

    About 50 years ago, John von Neumann proved that the coarsening rate of individual bubbles in a 2-D dry foam is a linear function of the number of edges of the polygonal bubble. Soon afterwards it was conjectured that a statistical analog holds in three dimensions: polyhedral bubbles with a given number F of faces have an average growth rate that scales linearly in F. Using a theorem by Minkowski, we derive a parameter-free analytical expression for the average growth rates and show that it is non-linear, asymptoting to a square-root power in F. Experimental data and detailed foam simulations are in exceptionally good agreement with the analytical results. A refined model incorporates foam disorder to further improve the predictive power of the theory.

  16. Sensitive electrochemical nonenzymatic glucose sensing based on anodized CuO nanowires on three-dimensional porous copper foam

    NASA Astrophysics Data System (ADS)

    Li, Zhenzhen; Chen, Yan; Xin, Yanmei; Zhang, Zhonghai

    2015-11-01

    In this work, we proposed to utilize three-dimensional porous copper foam (CF) as conductive substrate and precursor of in-situ growth CuO nanowires (NWs) for fabricating electrochemical nonenzymatic glucose sensors. The CF supplied high surface area due to its unique three-dimensional porous foam structure, and thus resulted in high sensitivity for glucose detection. The CuO NWs/CF based nonenzymatic sensors presented reliable selectivity, good repeatability, reproducibility, and stability. In addition, the CuO NWs/CF based nonenzymatic sensors have been employed for practical applications, and the glucose concentration in human serum was measured to be 4.96 ± 0.06 mM, agreed well with the value measured from the commercial available glucose sensor in hospital, and the glucose concentration in saliva was also estimated to be 0.91 ± 0.04 mM, which indicated that the CuO NWs/CF owned the possibility for noninvasive glucose detection. The rational design of CuO NWs/CF provided an efficient strategy for fabricating of electrochemical nonenzymatic biosensors.

  17. Sensitive electrochemical nonenzymatic glucose sensing based on anodized CuO nanowires on three-dimensional porous copper foam

    PubMed Central

    Li, Zhenzhen; Chen, Yan; Xin, Yanmei; Zhang, Zhonghai

    2015-01-01

    In this work, we proposed to utilize three-dimensional porous copper foam (CF) as conductive substrate and precursor of in-situ growth CuO nanowires (NWs) for fabricating electrochemical nonenzymatic glucose sensors. The CF supplied high surface area due to its unique three-dimensional porous foam structure, and thus resulted in high sensitivity for glucose detection. The CuO NWs/CF based nonenzymatic sensors presented reliable selectivity, good repeatability, reproducibility, and stability. In addition, the CuO NWs/CF based nonenzymatic sensors have been employed for practical applications, and the glucose concentration in human serum was measured to be 4.96 ± 0.06 mM, agreed well with the value measured from the commercial available glucose sensor in hospital, and the glucose concentration in saliva was also estimated to be 0.91 ± 0.04 mM, which indicated that the CuO NWs/CF owned the possibility for noninvasive glucose detection. The rational design of CuO NWs/CF provided an efficient strategy for fabricating of electrochemical nonenzymatic biosensors. PMID:26522446

  18. Preparation of Three-Dimensional Graphene Foams Using Powder Metallurgy Templates.

    PubMed

    Sha, Junwei; Gao, Caitian; Lee, Seoung-Ki; Li, Yilun; Zhao, Naiqin; Tour, James M

    2016-01-26

    A simple and scalable method which combines traditional powder metallurgy and chemical vapor deposition is developed for the synthesis of mesoporous free-standing 3D graphene foams. The powder metallurgy templates for 3D graphene foams (PMT-GFs) consist of particle-like carbon shells which are connected by multilayered graphene that shows high specific surface area (1080 m(2) g(-1)), good crystallization, good electrical conductivity (13.8 S cm(-1)), and a mechanically robust structure. The PMT-GFs did not break under direct flushing with DI water, and they were able to recover after being compressed. These properties indicate promising applications of PMT-GFs for fields requiring 3D carbon frameworks such as in energy-based electrodes and mechanical dampening. PMID:26678869

  19. Three-dimensional SnO2/carbon on Cu foam for high-performance lithium ion battery anodes.

    PubMed

    Chen, Weimin; Maloney, Scott; Wang, Wenyong

    2016-10-14

    SnO2 is an attractive anode material for lithium-ion batteries (LIBs) due to its high theoretical specific capacity (1491 mAh g(-1)), low cost, and environmental benignity. The main challenges for SnO2 anodes are their low intrinsic conductivity and poor cycling stability associated with their large volume changes during the charge and discharge process. Here, we present a simple chemical vapor deposition method to fabricate three-dimensional SnO2/carbon on Cu foam electrodes for LIBs. Such a three-dimensional electrode combines multiple advantages, including a continuous electrically conductive network, short pathways for electron transport and ion diffusion, and porous space to allow for the volume expansion of SnO2 nanoparticles. With this anode, superior electrochemical performance is achieved with a high reversible specific capacity of 1171 mAh g(-1) at a current density of 100 mA g(-1). A stable cycling performance as well as an excellent rate capability is also achieved. These outstanding lithium-storage properties suggest the strategy is a reliable approach for fabricating high-performance LIB electrodes. PMID:27587237

  20. Anti-inflammatory effects of three-dimensional graphene foams cultured with microglial cells.

    PubMed

    Song, Qin; Jiang, Ziyun; Li, Ning; Liu, Ping; Liu, Liwei; Tang, Mingliang; Cheng, Guosheng

    2014-08-01

    One of the key goals in nerve tissue engineering is to develop new materials which cause less or no neuroinflammation. Despite the rapid advances of using graphene as a neural interface material, it still remains unknown whether graphene could provoke neuroinflammation or not, and whether and how the topographical features of graphene influence the neuroinflammation induction. By immunofluorescence, Elisa technique, western blot, scanning electron microscope (SEM) methods, we investigated the pro- and/or anti-inflammatory responses of microglia in the graphene films (2D-graphene) or graphene foams (3D-graphene) culturing systems. Furthermore, the growth situations of the neural stem cells (NSCs) in the conditioned culture medium produced in the graphene substrates were evaluated. The results show that: 1) neither 2D nor 3D graphene induced distinct neuroinflammation when compared to the tissue culture polystyrene (TCPS) substrates; 2) the topographical structures of the graphene might affect the material/cell interactions, leading to disparate effects on lipopolysaccharide (LPS)-induced neuroinflammation; 3) 3D graphene exhibited a remarkable capability of rescuing LPS-induced neuroinflammation probably through the restriction of microglia morphological transformation by the unique topographical features on the surface, showing the ability of anti-inflammation against external insults, while 2D graphene failed to. These results provide insights into the diverse biological effects of the material's topographical structures and open new opportunity for the applications of graphene in neuroscience. PMID:24875763

  1. Structural evaluation of a nickel base super alloy metal foam via NDE and finite element

    NASA Astrophysics Data System (ADS)

    Abdul-Aziz, Ali; Abumeri, G.; Garg, Mohit; Young, P. G.

    2008-03-01

    Cellular materials are known to be useful in the application of designing light but stiff structures. This applies to various components used in various industries such as rotorcraft blades, car bodies or portable electronic devices. Structural application of the metal foam is typically confined to light weight sandwich panels, made up of thin solid face sheets and a metallic foam core. The resulting high-stiffness structure is lighter than that constructed only out of the solid metal material. The face sheets carry the applied in-plane and bending loads and the role of the foam core is separate the face sheets to carry some of the shear stresses, while remaining integral with the face sheet. Many challenges relating to the fabrication and testing of these metal foam panels continue to exist due to some mechanical properties falling short of their theoretical potential. Hence in this study, a detailed three dimensional foam structure is generated using series of 2D Computer Tomography (CT) scans, on Haynes 25 metal foam. Series of the 2D images are utilized to construct a high precision solid model including all the fine details within the metal foam as detected by the CT scanning technique. Subsequently, a finite element analysis is then performed on an as fabricated metal foam microstructures to evaluate the foam structural durability and behavior under tensile and compressive loading conditions. The analysis includes a progressive failure analysis (PFA) using GENOA code to further assess the damage initiation, propagation, and failure. The open cell metal foam material is a cobalt-nickel-chromium-tungsten alloy that combines excellent high-temperature strength with good resistance to oxidizing environments up to 1800 °F (980 °C) for prolonged exposures. The foam is formed by a powder metallurgy process with an approximate 100 pores per inch (PPI).

  2. Nickel-Cobalt Oxide Decorated Three-Dimensional Graphene as an Enzyme Mimic for Glucose and Calcium Detection.

    PubMed

    Wu, Meiyan; Meng, Shangjun; Wang, Qian; Si, Weili; Huang, Wei; Dong, Xiaochen

    2015-09-30

    Glucose and calcium ion play key roles in human bodies. The needlelike NiCo2O4 nanostructures are in situ deposited on three-dimensional graphene foam (3DGF) by a facile hydrothermal procedure. The structure and morphology of the hierarchical NiCo2O4/3DGF are characterized by scanning electron microscopy, transmission electron microscopy, and X-ray diffraction. With the self-standing NiCo2O4/3DGF as electrochemical electrode, it can realize the high-sensitivity detections for glucose and calcium ion. The limit of detection can reach 0.38 and 4.45 μM, respectively. In addition, the electrochemical electrode presents excellent selectivity for glucose and calcium ion. This study demonstrates that NiCo2O4/3DGF is a unique and promising material for practical application in both glucose and calcium ion sensing. PMID:26329273

  3. Preparation and characterization of three dimensional graphene foam supported platinum-ruthenium bimetallic nanocatalysts for hydrogen peroxide based electrochemical biosensors.

    PubMed

    Kung, Chih-Chien; Lin, Po-Yuan; Buse, Frederick John; Xue, Yuhua; Yu, Xiong; Dai, Liming; Liu, Chung-Chiun

    2014-02-15

    The large surface, the excellent dispersion and the high degrees of sensitivity of bimetallic nanocatalysts were the attractive features of this investigation. Graphene foam (GF) was a three dimensional (3D) porous architecture consisting of extremely large surface and high conductive pathways. In this study, 3D GF was used incorporating platinum-ruthenium (PtRu) bimetallic nanoparticles as an electrochemical nanocatalyst for the detection of hydrogen peroxide (H2O2). PtRu/3D GF nanocatalyst exhibited a remarkable performance toward electrochemical oxidation of H2O2 without any additional mediator showing a high sensitivity (1023.1 µA mM(-1)cm(-2)) and a low detection limit (0.04 µM) for H2O2. Amperometric results demonstrated that GF provided a promising platform for the development of electrochemical sensors in biosensing and PtRu/3D GF nanocatalyst possessed the excellent catalytic activity toward the H2O2 detection. A small particle size and a high degree of the dispersion in obtaining of large active surface area were important for the nanocatalyst for the best H2O2 detection in biosensing. Moreover, potential interference by ascorbic acid and uric acid appeared to be negligible. PMID:24012804

  4. Three-dimensional electrochemical immunosensor for sensitive detection of carcinoembryonic antigen based on monolithic and macroporous graphene foam.

    PubMed

    Liu, Jiyang; Wang, Jiao; Wang, Tianshu; Li, Dan; Xi, Fengna; Wang, Jin; Wang, Erkang

    2015-03-15

    A high performance three-dimensional (3D) electrochemical immunosensor was developed for sensitive detection of the tumor biomarker, carcinoembryonic antigen (CEA). Monolithic and macroporous graphene foam grown by chemical vapor deposition (CVD) served as the scaffold of the free-standing 3D electrode. Immuno-recognition interface was fabricated via simple and non-covalent immobilization of antibody using lectin-mediated strategy. Briefly, the well-known lectin macromolecule (concanavalin A, Con A) monolayer was functionalized on 3D graphene (3D-G) using in-situ polymerized polydopamine as the linker. Then the widely used horseradish peroxidase (HRP)-labeled antibody (anti-CEA) in immunoassays was efficiently immobilized to demonstrate the recognition interface via the biospecific affinity of lectin with sugarprotein. The 3D immunosensor is able to detect CEA with a wide linear range (0.1-750.0ngml(-1)), low detection limit (~90pgml(-1) at a signal-to-noise ratio of 3), and short incubation time (30min). Furthermore, this biosensor was used for the detection of the CEA level in real serum samples. PMID:25461170

  5. Surface Modification of Nickel Foams by a Slurry Aluminizing Process

    SciTech Connect

    Omar, H.; Papanastasiou, N.; Psyllaki, P.; Stergioudi, F.; Tsipas, D. N.; Tsipas, S. A.; Michailidis, N.

    2010-01-21

    A novel slurry-based process for aluminizing nickel foams while improving the mechanical properties and conserving the excellent ductility is reported. Cellular unalloyed nickel foams with 92% porosity and uniform pore size and distribution were used as a starting material. Several slurries of different compositions were examined to investigate the possibility of developing an aluminide-nickel intermetallic coating on a Ni foam without considerably degrading the original ductile properties of the foam. The process temperature was varying from 400 to 850 deg. C and the process holding time was ranging between 2h to 6h. Scanning electron microscopy with an energy dispersive X-ray spectrometry and X-Ray diffraction were applied to assess the effectiveness of the aluminizing process and determine both the optimum parameters of the procedure (slurry composition, holding temperature and time) and the concentration profiles across the coating cross-section. The mechanical behavior of the aluminized Ni-foams was evaluated by the conduction of micro-tension tests. The resulting Ni-foams after aluminization retain the pore structure of original Ni-foams and present a thick outer surface layer which consists of a range of aluminide phases. The mechanical properties of the Ni-foams aluminized in low process temperature were insignificantly affected.

  6. Hydrothermal deposition of manganese dioxide nanosheets on electrodeposited graphene covered nickel foam as a high-performance electrode for supercapacitors

    NASA Astrophysics Data System (ADS)

    Li, Yiju; Cao, Dianxue; Wang, Ying; Yang, Sainan; Zhang, Dongming; Ye, Ke; Cheng, Kui; Yin, Jinling; Wang, Guiling; Xu, Yang

    2015-04-01

    In this paper, the graphene oxide nanosheets are simultaneously reduced and deposited on nickel foam (denoted as Ni-foam@GNS) by one step electrodeposition method. The interconnected crumpled graphene nanosheets grown on Ni foam serve as a three-dimensional (3D) conductive skeleton for hydrothermal deposition of MnO2 nanosheets by in-situ redox reaction. The MnO2 nanosheets anchored on the graphene covered nickel foam (denoted as Ni-foam@GNS@MnO2) show unique 3D porous interconnected networks. The samples are characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), N2 adsorption-desorption measurements and fourier transform infrared spectroscopy (FT-IR). The capacitive performances are researched by cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The results reveal that the Ni-foam@GNS@MnO2 electrode exhibits a high specific capacitance of 462 F g-1 at 0.5 A g-1 and excellent capacitance retention of 93.1% after 5000 cycles at 10 A g-1. Furthermore, the Ni-foam@GNS@MnO2 electrode delivers a high energy density of 26.1 Wh kg-1 even at a high power density of 3981 W kg-1. These results demonstrate that the Ni-foam@GNS@MnO2 composite offers great promise in large-scale energy storage device applications.

  7. Preparation of a Binder-Free Three-Dimensional Carbon Foam/Silicon Composite as Potential Material for Lithium Ion Battery Anodes.

    PubMed

    Roy, Amit K; Zhong, Mingjie; Schwab, Matthias Georg; Binder, Axel; Venkataraman, Shyam S; Tomović, Željko

    2016-03-23

    We report a novel three-dimensional nitrogen containing carbon foam/silicon (CFS) composite as potential material for lithium ion battery anodes. Carbon foams were prepared by direct carbonization of low cost, commercially available melamine formaldehyde (MF, Basotect) foam precursors. The carbon foams thus obtained display a three-dimensional interconnected macroporous network structure with good electrical conductivity (0.07 S/cm). Binder free CFS composites used for electrodes were prepared by immersing the as-fabricated carbon foam into silicon nanoparticles dispersed in ethanol followed by solvent evaporation and secondary pyrolysis. In order to substantiate this new approach, preliminary electrochemical testing has been done. The first results on CFS electrodes demonstrated initial capacity of 1668 mAh/g with 75% capacity retention after 30 cycles of subsequent charging and discharging. In order to further enhance the electrochemical performance, silicon nanoparticles were additionally coated with a nitrogen containing carbon layer derived from codeposited poly(acrylonitrile). These carbon coated CFS electrodes demonstrated even higher performance with an initial capacity of 2100 mAh/g with 92% capacity retention after 30 cycles of subsequent charging and discharging. PMID:26909748

  8. Hydrothermal growth of vertically-aligned ordered mesoporous nickel oxide nanosheets on three-dimensional nickel framework for electrocatalytic oxidation of urea in alkaline medium

    NASA Astrophysics Data System (ADS)

    Wu, Mao-Sung; Lin, Guan-Wei; Yang, Run-Song

    2014-12-01

    Vertically-aligned α-Ni(OH)2 nanosheets are homogeneously covered on three-dimensional (3D) macroporous Ni foam and stainless steel (SS) sheet by a simple hydrothermal synthesis. After annealing at 300 °C, most of the α-Ni(OH)2 is transformed to cubic NiO. The NiO nanosheets exhibit ordered mesoporous structure. Electrolysis of urea is analyzed by cyclic voltammetry and potential step chronoamperometry in 1 M KOH electrolyte with 0.33 M urea. The electrocatalytic performance of NiO electrodes depends strongly on their configuration and substrate. Vertically-aligned NiO nanosheets favor the electrolysis of urea because they can provide more catalytic sites than the NiO powder with aggregated nanosheets. In addition, the large open space between vertically-aligned NiO nanosheets expedites the transport of electrolyte, urea, and gases. 3D macroporous Ni foam substrate is very helpful to the electrolysis of urea which allows for fast electron conduction, leading to a decrease of overpotential and the increase of oxidation current density. Consequently, the Ni foam-supported mesoporous NiO nanosheets can offer a much better electrocatalytic performance than SS-supported mesoporous NiO nanosheets and powder during electrolysis of urea.

  9. Modeling of abnormal mechanical properties of nickel-based single crystal superalloy by three-dimensional discrete dislocation dynamics

    NASA Astrophysics Data System (ADS)

    Yang, Hui; Li, Zhenhuan; Huang, Minsheng

    2014-12-01

    Unlike common single crystals, the nickel-based single crystal superalloy shows surprisingly anomalous flow strength (i.e. with the increase of temperature, the yield strength first increases to a peak value and then decreases) and tension-compression (TC) asymmetry. A comprehensive three-dimensional discrete dislocation dynamics (3D-DDD) procedure was developed to model these abnormal mechanical properties. For this purpose, a series of complicated dynamic evolution details of Kear-Wilsdorf (KW) locks, which are closely related to the flow strength anomaly and TC asymmetry, were incorporated into this 3D-DDD framework. Moreover, the activation of the cubic slip system, which is the origin of the decrease in yield strength with increasing temperature at relatively high temperatures, was especially taken into account by introducing a competition criterion between the unlocking of the KW locks and the activation of the cubic slip system. To test our framework, a series of 3D-DDD simulations were performed on a representative volume cell model with a cuboidal Ni3Al precipitate phase embedded in a nickel matrix. Results show that the present 3D-DDD procedure can successfully capture the dynamic evolution of KW locks, the flow strength anomaly and TC asymmetry. Then, the underlying dislocation mechanisms leading to these abnormal mechanical responses were investigated and discussed in detail. Finally, a cyclic deformation of the nickel-based single crystal superalloy was modeled by using the present DDD model, with a special focus on the influence of KW locks on the Bauschinger effect and cyclic softening.

  10. High power density microbial fuel cell with flexible 3D graphene-nickel foam as anode

    NASA Astrophysics Data System (ADS)

    Wang, Hanyu; Wang, Gongming; Ling, Yichuan; Qian, Fang; Song, Yang; Lu, Xihong; Chen, Shaowei; Tong, Yexiang; Li, Yat

    2013-10-01

    The structure and electrical conductivity of anode play a significant role in the power generation of microbial fuel cells (MFCs). In this study, we developed a three-dimensional (3D) reduced graphene oxide-nickel (denoted as rGO-Ni) foam as an anode for MFC through controlled deposition of rGO sheets onto the nickel foam substrate. The loading amount of rGO sheets and electrode surface area can be controlled by the number of rGO loading cycles. 3D rGO-Ni foam anode provides not only a large accessible surface area for microbial colonization and electron mediators, but also a uniform macro-porous scaffold for effective mass diffusion of the culture medium. Significantly, at a steady state of the power generation, the MFC device with flexible rGO-Ni electrodes produced an optimal volumetric power density of 661 W m-3 calculated based on the volume of anode material, or 27 W m-3 based on the volume of the anode chamber. These values are substantially higher than that of plain nickel foam, and other conventional carbon based electrodes (e.g., carbon cloth, carbon felt, and carbon paper) measured in the same conditions. To our knowledge, this is the highest volumetric power density reported for mL-scale MFC device with a pure strain of Shewanella oneidensis MR-1. We also demonstrated that the MFC device can be operated effectively in a batch-mode at least for a week. These new 3D rGO-Ni electrodes show great promise for improving the power generation of MFC devices.The structure and electrical conductivity of anode play a significant role in the power generation of microbial fuel cells (MFCs). In this study, we developed a three-dimensional (3D) reduced graphene oxide-nickel (denoted as rGO-Ni) foam as an anode for MFC through controlled deposition of rGO sheets onto the nickel foam substrate. The loading amount of rGO sheets and electrode surface area can be controlled by the number of rGO loading cycles. 3D rGO-Ni foam anode provides not only a large accessible

  11. Three-dimensional B,N-doped graphene foam as a metal-free catalyst for oxygen reduction reaction.

    PubMed

    Xue, Yuhua; Yu, Dingshan; Dai, Liming; Wang, Ruigang; Li, Dingqiang; Roy, Ajit; Lu, Fan; Chen, Hao; Liu, Yong; Qu, Jia

    2013-08-01

    Using a modified chemical vapor deposition (CVD) method, we have prepared a class of new graphene foams (GFs) doped with nitrogen, boron or both. Nitrogen-doped graphene foams (N-GFs) with a nitrogen doping level of 3.1 atom% were prepared by CVD of CH4 in the presence of NH3 while boron-doped graphene foams (B-GFs) with a boron doping level of 2.1 atom% were produced by using toluene and triethyl borate as a carbon and a boron source. On the other hand, graphene foams co-doped with nitrogen (4.5 atom%) and boron (3 atom%) (BN-GFs) were prepared by CVD using melamine diborate as the precursor. In all cases, scanning electron microscope (SEM) images revealed well-defined foam-like microstructures, while electrochemical measurements showed much higher electrocatalytic activities toward oxygen reduction reaction for the doped graphene foams than their undoped counterparts. PMID:23770584

  12. Highly conductive three-dimensional MnO2-carbon nanotube-graphene-Ni hybrid foam as a binder-free supercapacitor electrode.

    PubMed

    Zhu, Guoyin; He, Zhi; Chen, Jun; Zhao, Jin; Feng, Xiaomiao; Ma, Yanwen; Fan, Quli; Wang, Lianhui; Huang, Wei

    2014-01-21

    Carbon nanotube (CNT)-graphene hybrids grown on porous Ni foam are used as substrates to immobilize MnO2 nanoflakes, thus forming three-dimensional (3D) MnO2-CNT-graphene-Ni hybrid foam. The as-prepared hybrid materials could be used as supercapacitor electrodes directly without any binder and conductive additives, and fully maintain the high conductivity and high surface-to-volume ratio of CNTs, large pseudocapacitance of MnO2 nanoflakes and high porosity provided by the framework of Ni foam. The conductivity of the 3D MnO2-CNT-graphene-Ni foam is as high as 117 S cm(-1) due to the seamless integration of MnO2 nanoflakes, CNTs, graphene and Ni foam among the 3D frameworks, which guarantee its low internal resistance (1.25 ohm) when compacted into supercapacitor devices. In aqueous electrolytes, the 3D MnO2-CNT-graphene-Ni based prototype supercapacitors show specific capacitances of ~251 F g(-1) with good cycling stability at a current density of 1.0 A g(-1). In addition, these 3D hybrids also demonstrate their potential in all-solid-state flexible supercapacitors. PMID:24296659

  13. Morphological Study of Directionally Freeze-Cast Nickel Foams

    NASA Astrophysics Data System (ADS)

    Jo, Hyungyung; Kim, Min Jeong; Choi, Hyelim; Sung, Yung-Eun; Choe, Heeman; Dunand, David C.

    2016-03-01

    Nickel foams, consisting of 51 to 62 pct aligned, elongated pores surrounded by a network of Ni walls, were fabricated by reduction and sintering of directionally cast suspensions of nanometric NiO powders in water. Use of dispersant in the slurry considerably affected the foam morphology and microstructure at both the micro- and macro-scale, most likely by modifying ice solidification into dendrites (creating the aligned, elongated macro-pores) and NiO powder accumulation in the inter-dendritic space (creating the Ni walls with micro-pores). The mean width of the Ni walls, in foams solidified with and without dispersant, was 21 ± 5 and 75 ± 13 µm, respectively. Additionally, the foams with the dispersant showed less dense walls and rougher surfaces than those without the dispersant. Moreover, the fraction of closed pores present in the foam walls with the dispersant was higher than that of the samples without dispersant. We finally verified the potential energy application of the Ni foam produced in this study by carrying out a preliminary single-cell performance test with the Ni foam sample as the gas diffusion layer on the anode side of a polymer electrolyte membrane fuel cell.

  14. Combination nickel foam expanded nickel screen electrical connection supports for solid oxide fuel cells

    DOEpatents

    Draper, Robert; Prevish, Thomas; Bronson, Angela; George, Raymond A.

    2007-01-02

    A solid oxide fuel assembly is made, wherein rows (14, 25) of fuel cells (17, 19, 21, 27, 29, 31), each having an outer interconnection (20) and an outer electrode (32), are disposed next to each other with corrugated, electrically conducting expanded metal mesh member (22) between each row of cells, the corrugated mesh (22) having top crown portions and bottom portions, where the top crown portion (40) have a top bonded open cell nickel foam (51) which contacts outer interconnections (20) of the fuel cells, said mesh and nickel foam electrically connecting each row of fuel cells, and where there are no more metal felt connections between any fuel cells.

  15. Mechanical Simulation of the Localized Deformation in the Aluminum Foams: A Three-dimensional (3D) Structure Based Study

    NASA Astrophysics Data System (ADS)

    Kai, Zhu; Enyu, Guo; Wenqian, Zhou; Sansan, Shuai; Tao, Jing; Hongliang, Hou; Yanjin, Xu

    2015-06-01

    Metal-foam materials have been used increasingly in industry for their low-density, high-toughness and high impact resistance properties. Understanding the macro-scale mechanical properties of these materials is essential to evaluate their actual performance and thus to optimize the structures and properties accordingly. Synchrotron radiation X-ray microtomographytechnique is a promising method to study 3D structures at small length scales, which provides high spatial resolution and allows the researchers to observe the change of structures/features in situ without destroying the original objects. In this work, the real 3D structure of closed-cell aluminum foam was obtained by using synchrotron radiation X-ray microtomography. The reconstructed 3D model of the foam was further utilized as input for the subsequent mechanical study to investigate the localized deformation behaviors and evolution process of the foam under longitudinal quasi-static uniaxial compressive loading. By analyzing the simulated results, it is demonstrated that the deformation bands always initiate and propagate along the cell walls which are finally folded upon loading. And the large spherical cells are more susceptible to yielding, as well as to the stress concentration than the cells with other shapes. This finding is consistent with the experimental results.

  16. Interplay between cellular activity and three-dimensional scaffold-cell constructs with different foam structure processed by electron beam melting.

    PubMed

    Nune, Krishna C; Misra, R Devesh K; Gaytan, Sara M; Murr, Lawrence E

    2015-05-01

    The cellular activity, biological response, and consequent integration of scaffold-cell construct in the physiological system are governed by the ability of cells to adhere, proliferate, and biomineralize. In this regard, we combine cellular biology and materials science and engineering to fundamentally elucidate the interplay between cellular activity and interconnected three-dimensional foamed architecture obtained by a novel process of electron beam melting and computational tools. Furthermore, the organization of key proteins, notably, actin, vinclulin, and fibronectin, involved in cellular activity and biological functions and relationship with the structure was explored. The interconnected foamed structure with ligaments was favorable to cellular activity that includes cell attachment, proliferation, and differentiation. The primary rationale for favorable modulation of cellular functions is that the foamed structure provided a channel for migration and communication between cells leading to highly mineralized extracellular matrix (ECM) by the differentiating osteoblasts. The filopodial interaction amongst cells on the ligaments was a governing factor in the secretion of ECM, with consequent influence on maturation and mineralization. PMID:25111154

  17. Enhanced hydrogen production in microbial electrolysis cell with 3D self-assembly nickel foam-graphene cathode.

    PubMed

    Cai, Weiwei; Liu, Wenzong; Han, Jinglong; Wang, Aijie

    2016-06-15

    In comparison to precious metal catalyst especially Platinum (Pt), nickel foam (NF) owned cheap cost and unique three-dimensional (3D) structure, however, it was scarcely applied as cathode material in microbial electrolysis cell (MEC) as the intrinsic laggard electrochemical activity for hydrogen recovery. In this study, a self-assembly 3D nickel foam-graphene (NF-G) cathode was fabricated by facile hydrothermal approach for hydrogen evolution in MECs. Electrochemical analysis (linear scan voltammetry and electrochemical impedance spectroscopy) revealed the improved electrochemical activity and effective mass diffusion after coating with graphene. NF-G as cathode in MEC showed a significant enhancement in hydrogen production rate compared with nickel foam at a variety of biases. Noticeably, NF-G showed a comparable averaged hydrogen production rate (1.31 ± 0.07 mL H2 mL(-1) reactor d(-1)) to Platinum/carbon (Pt/C) (1.32 ± 0.07 mL H2 mL(-1) reactor d(-1)) at 0.8 V. Profitable energy recovery could be achieved by NF-G cathode at higher applied voltage, which performed the best hydrogen yield of 3.27 ± 0.16 mol H2 mol(-1) acetate at 0.8 V and highest energy efficiency of 185.92 ± 6.48% at 0.6 V. PMID:26807526

  18. Hollow SnO2@Co3O4 core-shell spheres encapsulated in three-dimensional graphene foams for high performance supercapacitors and lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhao, Bo; Huang, Sheng-Yun; Wang, Tao; Zhang, Kai; Yuen, Matthew M. F.; Xu, Jian-Bin; Fu, Xian-Zhu; Sun, Rong; Wong, Ching-Ping

    2015-12-01

    Hollow SnO2@Co3O4 spheres are fabricated using 300 nm spherical SiO2 particles as template. Then three-dimensional graphene foams encapsulated hollow SnO2@Co3O4 spheres are successfully obtained through self-assembly in hydrothermal process from graphene oxide nanosheets and metal oxide hollow spheres. The three-dimensional graphene foams encapsulated architectures could greatly improve the capacity, cycling stability and rate capability of hollow SnO2@Co3O4 spheres electrodes due to the highly conductive networks and flexible buffering matrix. The three-dimensional graphene foams encapsulated hollow SnO2@Co3O4 spheres are promising electrode materials for supercapacitors and lithium-ion batteries.

  19. Synthesis, Microstructure and Properties of Nickel Aluminide Foams

    NASA Technical Reports Server (NTRS)

    Dunand, David C.

    2003-01-01

    Two Ph.D. students were involved in the project: Mr. Christopher Schuh (part-time, graduated in Spring 2001) and Ms. Andrea Hodge (full-time, graduated Summer 2002). One post-doctoral fellow, Dr. Heeman Choe, worked full-time on the project from July to December 2002. A new process to aluminize and chromize nickel foams was created. A kinetic aluminization model was developed. Creep testing was conducted on the foams. A finite-element model and a simplified analytical model for foam creep were produced. Four articles were written: one is published, two are accepted for publication, and one is in preparation. Ms. Hodge spent four months at NASA Glenn Research Center (9-12/2001 and 2-3/2002) under the supervision of Dr. Nathal. She conducted research on NiAl foam fabrication, mechanical testing and numerical modeling. She gave a talk at the ASM annual conference in November 2001 and presented her results at NASA in December 2001.

  20. Porous three-dimensional graphene foam/Prussian blue composite for efficient removal of radioactive (137)Cs.

    PubMed

    Jang, Sung-Chan; Haldorai, Yuvaraj; Lee, Go-Woon; Hwang, Seung-Kyu; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

    2015-01-01

    In this study, a simple one-step hydrothermal reaction is developed to prepare composite based on Prussian blue (PB)/reduced graphene oxide foam (RGOF) for efficient removal of radioactive cesium ((137)Cs) from contaminated water. Scanning electron microscopy and transmission electron microscopy show that cubic PB nanoparticles are decorated on the RGO surface. Owing to the combined benefits of RGOF and PB, the composite shows excellent removal efficiency (99.5%) of (137)Cs from the contaminated water. The maximum adsorption capacity is calculated to be 18.67 mg/g. An adsorption isotherm fit-well the Langmuir model with a linear regression correlation value of 0.97. This type of composite is believed to hold great promise for the clean-up of (137)Cs from contaminated water around nuclear plants and/or after nuclear accidents. PMID:26670798

  1. Porous three-dimensional graphene foam/Prussian blue composite for efficient removal of radioactive 137Cs

    PubMed Central

    Jang, Sung-Chan; Haldorai, Yuvaraj; Lee, Go-Woon; Hwang, Seung-Kyu; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

    2015-01-01

    In this study, a simple one-step hydrothermal reaction is developed to prepare composite based on Prussian blue (PB)/reduced graphene oxide foam (RGOF) for efficient removal of radioactive cesium (137Cs) from contaminated water. Scanning electron microscopy and transmission electron microscopy show that cubic PB nanoparticles are decorated on the RGO surface. Owing to the combined benefits of RGOF and PB, the composite shows excellent removal efficiency (99.5%) of 137Cs from the contaminated water. The maximum adsorption capacity is calculated to be 18.67 mg/g. An adsorption isotherm fit-well the Langmuir model with a linear regression correlation value of 0.97. This type of composite is believed to hold great promise for the clean-up of 137Cs from contaminated water around nuclear plants and/or after nuclear accidents. PMID:26670798

  2. Porous three-dimensional graphene foam/Prussian blue composite for efficient removal of radioactive 137Cs

    NASA Astrophysics Data System (ADS)

    Jang, Sung-Chan; Haldorai, Yuvaraj; Lee, Go-Woon; Hwang, Seung-Kyu; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

    2015-12-01

    In this study, a simple one-step hydrothermal reaction is developed to prepare composite based on Prussian blue (PB)/reduced graphene oxide foam (RGOF) for efficient removal of radioactive cesium (137Cs) from contaminated water. Scanning electron microscopy and transmission electron microscopy show that cubic PB nanoparticles are decorated on the RGO surface. Owing to the combined benefits of RGOF and PB, the composite shows excellent removal efficiency (99.5%) of 137Cs from the contaminated water. The maximum adsorption capacity is calculated to be 18.67 mg/g. An adsorption isotherm fit-well the Langmuir model with a linear regression correlation value of 0.97. This type of composite is believed to hold great promise for the clean-up of 137Cs from contaminated water around nuclear plants and/or after nuclear accidents.

  3. General Preparation of Three-Dimensional Porous Metal Oxide Foams Coated with Nitrogen-Doped Carbon for Enhanced Lithium Storage.

    PubMed

    Lu, Ke; Xu, Jiantie; Zhang, Jintao; Song, Bin; Ma, Houyi

    2016-07-13

    Porous metal oxide architectures coated with a thin layer of carbon are attractive materials for energy storage applications. Here, a series of porous metal oxide (e.g., vanadium oxides, molybdenum oxides, manganese oxides) foams with/without nitrogen-doped carbon (N-C) coating have been synthesized via a general surfactant-assisted template method, involving the formation of porous metal oxides coated with 1-hexadecylamine (HDA) and a subsequent thermal treatment. The presence of HDA is of importance for the formation of a porous structure, and the successive pyrolysis of such a nitrogen-containing surfactant generates nitrogen-doped carbon (N-C) coated on the surface of metal oxides, which also provides a facile way to adjust the valence states of metal oxides via the carbothermal reduction reaction. When used as electrode materials, the highly porous metal oxides with N-C coating exhibited enhanced performance for lithium ion storage, thanks to the unique 3D structures associated with highly porous structure and thin N-C coating. Typically, the porous metal oxides (V2O5, MoO3, MnO2) exhibited discharge capacities of 286, 303, and 463 mAh g(-1) at current densities of 30 and 100 mA g(-1), respectively. In contrast, the metal oxides with low valences and carbon coating (VO2@N-C, MoO2@N-C, and MnO@N-C) exhibited improved capacities of 461, 613, and 892 mAh g(-1). The capacity retentions of about 87.5, 80.2, and 85.0% for VO2@N-C, MoO2@N-C, and MnO@N-C were achieved after 600 cycles, suggesting the acceptable cycling stability. The present strategy would provide general guidance for preparing porous metal oxide foams with enhanced lithium storage performances. PMID:27322176

  4. Three-Dimensional Cu Foam-Supported Single Crystalline Mesoporous Cu2O Nanothorn Arrays for Ultra-Highly Sensitive and Efficient Nonenzymatic Detection of Glucose.

    PubMed

    Dong, Chaoqun; Zhong, Hua; Kou, Tianyi; Frenzel, Jan; Eggeler, Gunther; Zhang, Zhonghua

    2015-09-16

    Highly sensitive and efficient biosensors play a crucial role in clinical, environmental, industrial, and agricultural applications, and tremendous efforts have been dedicated to advanced electrode materials with superior electrochemical activities and low cost. Here, we report a three-dimensional binder-free Cu foam-supported Cu2O nanothorn array electrode developed via facile electrochemistry. The nanothorns growing in situ along the specific direction of <011> have single crystalline features and a mesoporous surface. When being used as a potential biosensor for nonenzyme glucose detection, the hybrid electrode exhibits multistage linear detection ranges with ultrahigh sensitivities (maximum of 97.9 mA mM(-1) cm(-2)) and an ultralow detection limit of 5 nM. Furthermore, the electrode presents outstanding selectivity and stability toward glucose detection. The distinguished performances endow this novel electrode with powerful reliability for analyzing human serum samples. These unprecedented sensing characteristics could be ascribed to the synergistic action of superior electrochemical catalytic activity of nanothorn arrays with dramatically enhanced surface area and intimate contact between the active material (Cu2O) and current collector (Cu foam), concurrently supplying good conductivity for electron/ion transport during glucose biosensing. Significantly, our findings could guide the fabrication of new metal oxide nanostructures with well-organized morphologies and unique properties as well as low materials cost. PMID:26305112

  5. Incorporation of Nitrogen Defects for Efficient Reduction of CO2 via Two-Electron Pathway on Three-Dimensional Graphene Foam.

    PubMed

    Wu, Jingjie; Liu, Mingjie; Sharma, Pranav P; Yadav, Ram Manohar; Ma, Lulu; Yang, Yingchao; Zou, Xiaolong; Zhou, Xiao-Dong; Vajtai, Robert; Yakobson, Boris I; Lou, Jun; Ajayan, Pulickel M

    2016-01-13

    The practical recycling of carbon dioxide (CO2) by the electrochemical reduction route requires an active, stable, and affordable catalyst system. Although noble metals such as gold and silver have been demonstrated to reduce CO2 into carbon monoxide (CO) efficiently, they suffer from poor durability and scarcity. Here we report three-dimensional (3D) graphene foam incorporated with nitrogen defects as a metal-free catalyst for CO2 reduction. The nitrogen-doped 3D graphene foam requires negligible onset overpotential (-0.19 V) for CO formation, and it exhibits superior activity over Au and Ag, achieving similar maximum Faradaic efficiency for CO production (∼85%) at a lower overpotential (-0.47 V) and better stability for at least 5 h. The dependence of catalytic activity on N-defect structures is unraveled by systematic experimental investigations. Indeed, the density functional theory calculations confirm pyridinic N as the most active site for CO2 reduction, consistent with experimental results. PMID:26651056

  6. High areal capacitance three-dimensional Ni@Ni(OH)2 foams via in situ oxidizing Ni foams in mild aqueous solution

    NASA Astrophysics Data System (ADS)

    Zhou, Qingfeng; Cui, Mangwei; Tao, Keyu; Yang, Yongzhen; Liu, Xuguang; Kang, Litao

    2016-03-01

    In this work, commercial Ni foams are directly oxidized into Ni@Ni(OH)2 foams in a mild NH4NO3 solution at 80 °C. When used as binder-free electrodes, these Ni@Ni(OH)2 electrodes demonstrate a high areal capacitance of 6.4 F/cm2 at a current density of 2.5 mA/cm2, or 1.62 F/cm2 at a high current density of 30 mA/cm2. Nevertheless, they show a poor cycling ability with 70.4% (or 42%) capacitance retention after 2000 (or 5000) cycles at 30 mA/cm2. This kind of electrodes has a promising application in low-cost, high-performance supercapacitor, if an effective strategy is found to improve their cycling ability.

  7. Graphene hydrogels deposited in nickel foams for high-rate electrochemical capacitors.

    PubMed

    Chen, Ji; Sheng, Kaixuan; Luo, Peihui; Li, Chun; Shi, Gaoquan

    2012-08-28

    Graphene hydrogel/nickel foam composite electrodes for high-rate electrochemical capacitors are produced by reduction of an aqueous dispersion of graphene oxide in a nickel foam (upper half of figure). The micropores of the hydrogel are exposed to the electrolyte so that ions can enter and form electrochemical double-layers. The nickel framework shortens the distances of charge transfer. Therefore, the electrochemical capacitor exhibits highrate performance (see plots). PMID:22786775

  8. Effective Thermal Conductivity of High Porosity Open Cell Nickel Foam

    NASA Technical Reports Server (NTRS)

    Sullins, Alan D.; Daryabeigi, Kamran

    2001-01-01

    The effective thermal conductivity of high-porosity open cell nickel foam samples was measured over a wide range of temperatures and pressures using a standard steady-state technique. The samples, measuring 23.8 mm, 18.7 mm, and 13.6 mm in thickness, were constructed with layers of 1.7 mm thick foam with a porosity of 0.968. Tests were conducted with the specimens subjected to temperature differences of 100 to 1000 K across the thickness and at environmental pressures of 10(exp -4) to 750 mm Hg. All test were conducted in a gaseous nitrogen environment. A one-dimensional finite volume numerical model was developed to model combined radiation/conduction heat transfer in the foam. The radiation heat transfer was modeled using the two-flux approximation. Solid and gas conduction were modeled using standard techniques for high porosity media. A parameter estimation technique was used in conjunction with the measured and predicted thermal conductivities at pressures of 10(exp -4) and 750 mm Hg to determine the extinction coefficient, albedo of scattering, and weighting factors for modeling the conduction thermal conductivity. The measured and predicted conductivities over the intermediate pressure values differed by 13%.

  9. Facile synthesis of polypyrrole functionalized nickel foam with catalytic activity comparable to Pt for the poly-generation of hydrogen and electricity

    NASA Astrophysics Data System (ADS)

    Tang, Tiantian; Li, Kan; Shen, Zhemin; Sun, Tonghua; Wang, Yalin; Jia, Jinping

    2016-01-01

    Polypyrrole functionalized nickel foam is facilely prepared through the potentiostatic electrodeposition. The PPy-functionalized Ni foam functions as a hydrogen-evolution cathode in a rotating disk photocatalytic fuel cell, in which hydrogen energy and electric power are generated by consuming organic wastes. The PPy-functionalized Ni foam cathode exhibits stable catalytic activities after thirteen continuous runs. Compared with net or plate structure, the Ni foam with a unique three-dimensional reticulate structure is conducive to the electrodeposition of PPy. Compared with Pt-group electrode, PPy-coated Ni foam shows a satisfactory catalytic performance for the H2 evolution. The combination of PPy and Ni forms a synergistic effect for the rapid trapping and removal of proton from solution and the catalytic reduction of proton to hydrogen. The PPy-functionalized Ni foam could be applied in photocatalytic and photoelectrochemical generation of H2. In all, we report a low cost, high efficient and earth abundant PPy-functionalized Ni foam with a satisfactory catalytic activities comparable to Pt for the practical application of poly-generation of hydrogen and electricity.

  10. Enhanced Field-Emission Performance from Carbon Nanotube Emitters on Nickel Foam Cathodes

    NASA Astrophysics Data System (ADS)

    Song, Meng; Xu, Peng; Han, Lijing; Yi, Lan; Wang, Xu; Li, Zhenhua; Shang, Xuefu; Wang, Xiumin; Wu, Huizhen; Zhao, Pei; Song, Yenan; Wang, Miao

    2016-04-01

    We present a three-dimensionally configured cathode with enhanced field-emission performance formed by combining carbon nanotube (CNT) emitters with a nickel foam (NiF) substrate via a conventional screen-printing technique. The CNT/NiF cathode has low turn-on electric field of 0.53 V μm-1 (with current density of 10 μA cm-2) and threshold electric field of 0.87 V μm-1 (with current density of 0.1 mA cm-2), and a very high field enhancement factor of 1.4 × 104. The porous structure of the NiF substrate can greatly improve the field-emission properties due to its large specific surface area that can accommodate more CNTs and increase the emitter density, as well as its high electrical and thermal conductivities that facilitate current transition and heat dissipation in the cathode. Most importantly, the local electric field was also enhanced by the multistage effect resulting from the rough metal surface, which furthermore leads to a high field enhancement factor. We believe that this improved field-emission performance makes such cathodes promising candidates for use in various field-emission applications.

  11. Three-dimensional hole transport in nickel oxide by alloying with MgO or ZnO

    NASA Astrophysics Data System (ADS)

    Alidoust, Nima; Carter, Emily A.

    2015-11-01

    It has been shown previously that the movement of a hole in nickel oxide is confined to two dimensions, along a single ferromagnetic plane. Such confinement may hamper hole transport when NiO is used as a p-type transparent conductor in various solar energy conversion technologies. Here, we use the small polaron model, along with unrestricted Hartree-Fock and complete active space self-consistent field calculations to show that forming substitutional MxNi1-xO alloys with M = Mg or Zn reduces the barrier for movement of a hole away from the ferromagnetic plane to which it is confined. Such reduction occurs for hole transfer alongside one or two M ions that have been substituted for Ni ions. Furthermore, the Mg and Zn ions do not trap holes on O sites in their vicinity, and NiO's transparency is preserved upon forming the alloys. Thus, forming MxNi1-xO alloys with M = Mg or Zn may enhance NiO's potential as a p-type transparent conducting oxide, by disrupting the two-dimensional confinement of holes in pure NiO.

  12. Nickel foam-supported polyaniline cathode prepared with electrophoresis for improvement of rechargeable Zn battery performance

    NASA Astrophysics Data System (ADS)

    Xia, Yang; Zhu, Derong; Si, Shihui; Li, Degeng; Wu, Sen

    2015-06-01

    Porous nickel foam is used as a substrate for the development of rechargeable zinc//polyaniline battery, and the cathode electrophoresis of PANI microparticles in non-aqueous solution is applied to the fabrication of Ni foam supported PANI electrode, in which the corrosion of the nickel foam substrate is prohibited. The Ni foam supported PANI cathode with high loading is prepared by PANI electrophoretic deposition, and followed by PANI slurry casting under vacuum filtration. The electrochemical charge storage performance for PANI material is significantly improved by using nickel foam substrate via the electrophoretic interlayer. The specific capacity of the nickel foam-PANI electrode with the electrophoretic layer is higher than the composite electrode without the electrophoretic layer, and the specific capacity of PANI supported by Ni foam reaches up to 183.28 mAh g-1 at the working current of 2.5 mA cm-2. The present electrophoresis deposition method plays the facile procedure for the immobilization of PANI microparticles onto the surface of non-platinum metals, and it becomes feasible to the use of the Ni foam supported PANI composite cathode for the Zn/PANI battery in weak acidic electrolyte.

  13. Three-dimensional honeycomb-like structured zero-valent iron/chitosan composite foams for effective removal of inorganic arsenic in water.

    PubMed

    Su, Fengchao; Zhou, Hongjian; Zhang, Yunxia; Wang, Guozhong

    2016-09-15

    A facile freeze-drying method was presented to fabricate three dimensional (3D) honeycomb-like structured nanoscale zero-valent iron/chitosan composite foams (ICCFs) for effective removal of inorganic arsenic in water. It was found that freezing temperature has important influence on the formation of 3D network structure of ICCFs. The ICCFs obtained at freeze temperature of -80°C exhibits oriented porous structure with good mechanical property than that at -20°C, thus improved excellent removal capability of As(III) and As(V) up to 114.9mgg(-1) and 86.87mgg(-1), respectively. Further, the adsorption kinetics of ICCFs on As(III) and As(V) can be described by pseudo-second order model and their adsorption isotherms follow Langmuir adsorption model. The superior removal performance of ICCFs on As(III) and As(V) can be ascribed to its oriented porous structure with abundant adsorption active sites resulted from nZVI and O, N-containing functional groups in ICCFs. Importantly, it was found that the O, N-containing functional groups of chitosan in ICCFs can adequately bind with the dissolved Fe(3+) ions from oxidation of nZVI to form Fe(3+)-Chitosan complex during removal of As(III) and As(V), thus effectively avoiding the dissolved Fe(3+) ions into solution to produce secondary pollution. A possible adsorption-coupled reduction mechanism of ICCFs on As(III) and As(V) was also proposed based on the experimental results. We believe that this work would be helpful to develop low-cost and abundant chitosan-based materials as high performance adsorbents for environmental remediation applications. PMID:27362398

  14. Hierarchical Mesoporous Zinc-Nickel-Cobalt Ternary Oxide Nanowire Arrays on Nickel Foam as High-Performance Electrodes for Supercapacitors.

    PubMed

    Wu, Chun; Cai, Junjie; Zhang, Qiaobao; Zhou, Xiang; Zhu, Ying; Shen, Pei Kang; Zhang, Kaili

    2015-12-01

    Nickel foam supported hierarchical mesoporous Zn-Ni-Co ternary oxide (ZNCO) nanowire arrays are synthesized by a simple two-step approach including a hydrothermal method and subsequent calcination process and directly utilized for supercapacitive investigation for the first time. The nickel foam supported hierarchical mesoporous ZNCO nanowire arrays possess an ultrahigh specific capacitance value of 2481.8 F g(-1) at 1 A g(-1) and excellent rate capability of about 91.9% capacitance retention at 5 A g(-1). More importantly, an asymmetric supercapacitor with a high energy density (35.6 Wh kg(-1)) and remarkable cycle stability performance (94% capacitance retention over 3000 cycles) is assembled successfully by employing the ZNCO electrode as positive electrode and activated carbon as negative electrode. The remarkable electrochemical behaviors demonstrate that the nickel foam supported hierarchical mesoporous ZNCO nanowire array electrodes are highly desirable for application as advanced supercapacitor electrodes. PMID:26575957

  15. Three-dimensional carbon- and binder-free nickel nanowire arrays as a high-performance and low-cost anode for direct hydrogen peroxide fuel cell

    NASA Astrophysics Data System (ADS)

    Ye, Ke; Guo, Fen; Gao, Yinyi; Zhang, Dongming; Cheng, Kui; Zhang, Wenping; Wang, Guiling; Cao, Dianxue

    2015-12-01

    A novel three-dimensional carbon- and binder-free nickel nanowire arrays (Ni NAs) electrode is successfully fabricated by a facile galvanostatic electrodeposition method using polycarbonate membrane as the template. The Ni NAs electrode achieves a oxidation current density (divided by the electroactive surface areas of Ni) of 25.1 mA cm-2 in 4 mol L-1 KOH and 0.9 mol L-1 H2O2 at 0.2 V (vs. Ag/AgCl) accompanied with a desirable stability, which is significantly higher than the catalytic activity of H2O2 electro-oxidation achieved previously with precious metals as catalysts. The impressive electrocatalytic performance is largely attributed to the superior 3D open structure and high electronic conductivity, which ensures the high utilization of Ni surfaces and makes the electrode have higher electrochemical activity. The apparent activation energy of H2O2 electro-oxidation on the Ni NAs catalyst is 13.59 kJ mol-1. A direct peroxide-peroxide fuel cell using the Ni NAs as anode exhibits a peak power density of 48.7 mW cm-2 at 20 °C. The electrode displays a great promise as the anode of direct peroxide-peroxide fuel cell due to its low cost, high activity and stability.

  16. Fabrication of nickel-foam-supported layered zinc-cobalt hydroxide nanoflakes for high electrochemical performance in supercapacitors.

    PubMed

    Yuan, Peng; Zhang, Ning; Zhang, Dan; Liu, Tao; Chen, Limiao; Liu, Xiaohe; Ma, Renzhi; Qiu, Guanzhou

    2014-10-01

    Nickel foam supported Zn-Co hydroxide nanoflakes were fabricated by a facile solvothermal method. Benefited from the unique structure of Zn-Co hydroxide nanoflakes on a nickel foam substrate, the as prepared materials exhibited an excellent specific capacitance of 901 F g(-1) at 5 A g(-1) and remarkable cycling stability as electrode materials in supercapacitors. PMID:25110896

  17. Formation and Characterization of Ni Nanofiber Catalysts on Nickel Metallic Foam by Electrospinning Process.

    PubMed

    Yeom, Hee Chul; Moon, Dong Ju; Lee, Kwan Young; Kim, Sang Woo

    2015-07-01

    We report the fabrication of nickel nanofiber catalysts supported on nickel metallic foam using a modified electrospinning with a grounded rotor and sequential reduction process. The robust deposition of aligned Ni nanofibers with a uniform morphology on the highly porous surfaces of the metallic foam could be achieved by controlling electrospinning parameters such as applied voltage, tip-collector-distance (TCD), concentration of polymer, and humidity. The diameters of the obtained nanofibers decreased with increasing voltage and TCDs. The uniform and thinnest Ni nanofibers on the Ni foam were obtained at a humidity of less than 30%, 15 kV applied voltage, and 17 cm TCD when using a precursor composed of nickel nitrate salt and poly(vinyl) pyrrolidone. The Ni foam catalyst support exhibited the superior thermal conducting property than other supports of MgO-MgAl2O4, Al2O3, and SiC, enabling to a higher heat transfer during catalytic reaction. As a result, the Ni nanofiber catalyst with a high surface area and superior heat transfer performance, which is supported on the metallic foam, were successfully fabricated via a modified electrospinning for potential application of XTL process converting anything to liquids, such as for Gas-to-Liquid (GTL), Coal-to-Liquid (CTL), and Biomass-to-Liquid (BTL). PMID:26373099

  18. Fracture of Open-Cell Nickel Foams Under Quasi-Static Tensile Loading

    NASA Astrophysics Data System (ADS)

    Shehata Aly, Mohamed

    2010-12-01

    Open-cell nickel foams with average pore size of 600 μm have been subjected to room temperature tensile tests to explore their tensile properties. Using a state of the art extensometer of noncontact type, foam properties as ultimate tensile strength, yield strength, and the Young's modulus ( E) have been measured accurately. The reason behind the usage of this kind of extensometer is to avoid completely any minor deformation that might be caused by the attachment of conventional extensometer to the sample's surface prior to testing. The function of this extensometer is based on the usage of a laser (CCD) camera that detects and records the dimensional changes as soon as the load is applied. A series of cyclic loading-unloading tests was performed to determine the foam's Young's modulus. The fracture behavior of foam cells was observed to be ductile. Complete separation of struts or cell walls took place successively by necking.

  19. Titanium-nickel shape memory alloy foams for bone tissue engineering.

    PubMed

    Xiong, J Y; Li, Y C; Wang, X J; Hodgson, P D; Wen, C E

    2008-07-01

    Titanium-nickel (TiNi) shape memory alloy (SMA) foams with an open-cell porous structure were fabricated by space-holder sintering process and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. The mechanical properties and shape memory properties of the TiNi foam samples were investigated using compressive test. Results indicate that the plateau stresses and elastic moduli of the foams under compression decrease with the increase of their porosities. The plateau stresses and elastic moduli are measured to be from 1.9 to 38.3 MPa and from 30 to 860 MPa for the TiNi foam samples with porosities ranged from 71% to 87%, respectively. The mechanical properties of the TiNi alloy foams can be tailored to match those of bone. The TiNi alloy foams exhibit shape memory effect (SME), and it is found that the recoverable strain due to SME decreases with the increase of foam porosity. PMID:19627791

  20. Three-dimensional carbon foam supported tin oxide nanocrystallites with tunable size range: Sulfonate anchoring synthesis and high rate lithium storage properties

    NASA Astrophysics Data System (ADS)

    Ma, Yue; Asfaw, Habtom Desta; Edström, Kristina

    2015-10-01

    The development of a free-standing electrode with high rate capability requires the realization of facile electrolyte percolation, fast charge transfer at the electrode-electrolyte interface as well as the intimate electrical wiring to the current collector. Employing a sulfonated high internal phase emulsion polymer (polyHIPE) as the carbon precursor, we developed a free-standing composite of carbon foam encapsulated SnO2 nanocrystallites, which simultaneously satisfies the aforementioned requirements. When directly evaluated in the pouch cell without using the binder, carbon additive or metallic current collector, the best performing composite exhibits a good rate performance up to 8 A g-1 and very stable cyclability for 250 cycles. This cycling performance was attributed to the synergistic coupling of hierarchical macro/mesoporous carbon foam and SnO2 nanocrystals with optimized size range. Postmortem characterizations unveiled the significant influence of subtle size variation of oxides on the electrochemical performance.

  1. Fabrication of High-Temperature Heat Exchangers by Plasma Spraying Exterior Skins on Nickel Foams

    NASA Astrophysics Data System (ADS)

    Hafeez, P.; Yugeswaran, S.; Chandra, S.; Mostaghimi, J.; Coyle, T. W.

    2016-06-01

    Thermal-sprayed heat exchangers were tested at high temperatures (750 °C), and their performances were compared to the foam heat exchangers made by brazing Inconel sheets to their surface. Nickel foil was brazed to the exterior surface of 10-mm-thick layers of 10 and 40 PPI nickel foam. A plasma torch was used to spray an Inconel coating on the surface of the foil. A burner test rig was built to produce hot combustion gases that flowed over exposed face of the heat exchanger. Cooling air flowed through the foam heat exchanger at rates of up to 200 SLPM. Surface temperature and air inlet/exit temperature were measured. Heat transfer to air flowing through the foam was significantly higher for the thermally sprayed heat exchangers than for the brazed heat exchangers. On an average, thermally sprayed heat exchangers show 36% higher heat transfer than conventionally brazed foam heat exchangers. At low flow rates, the convective resistance is large (~4 × 10-2 m2 K/W), and the effect of thermal contact resistance is negligible. At higher flow rates, the convective resistance decreases (~2 × 10-3 m2 K/W), and the lower contact resistance of the thermally sprayed heat exchanger provides better performance than the brazed heat exchangers.

  2. Fabrication of High-Temperature Heat Exchangers by Plasma Spraying Exterior Skins on Nickel Foams

    NASA Astrophysics Data System (ADS)

    Hafeez, P.; Yugeswaran, S.; Chandra, S.; Mostaghimi, J.; Coyle, T. W.

    2016-05-01

    Thermal-sprayed heat exchangers were tested at high temperatures (750 °C), and their performances were compared to the foam heat exchangers made by brazing Inconel sheets to their surface. Nickel foil was brazed to the exterior surface of 10-mm-thick layers of 10 and 40 PPI nickel foam. A plasma torch was used to spray an Inconel coating on the surface of the foil. A burner test rig was built to produce hot combustion gases that flowed over exposed face of the heat exchanger. Cooling air flowed through the foam heat exchanger at rates of up to 200 SLPM. Surface temperature and air inlet/exit temperature were measured. Heat transfer to air flowing through the foam was significantly higher for the thermally sprayed heat exchangers than for the brazed heat exchangers. On an average, thermally sprayed heat exchangers show 36% higher heat transfer than conventionally brazed foam heat exchangers. At low flow rates, the convective resistance is large (~4 × 10-2 m2 K/W), and the effect of thermal contact resistance is negligible. At higher flow rates, the convective resistance decreases (~2 × 10-3 m2 K/W), and the lower contact resistance of the thermally sprayed heat exchanger provides better performance than the brazed heat exchangers.

  3. Microwave-assisted synthesis of simonkolleite nanoplatelets on nickel foam-graphene with enhanced surface area for high-performance supercapacitors.

    PubMed

    Khamlich, S; Mokrani, T; Dhlamini, M S; Mothudi, B M; Maaza, M

    2016-01-01

    Simonkolleite (Zn5(OH)8Cl2·H2O) nanoplatelets has been deposited on nickel foam-supported graphene by using an efficient microwave-assisted hydrothermal method. The three-dimensional (3D) porous microstructure of the as-fabricated nickel foam-graphene/simonkolleite (NiF-G/SimonK) composite is beneficial to electrolyte penetration and ions exchange, whereas graphene provide improved electronic conductivity. Structural and morphological characterizations confirmed the presence of highly crystalline hexagonal-shaped nanoplatelets of simonkolleite. Field emission scanning electron microscope (FE-SEM) of the NiF-G/SimonK composite revealed that the SimonK nanoplatelets were evenly distributed on the surface of NiF-G and interlaced with each other, resulting in a higher specific surface area of 35.69 m(2) g(-1) compared to SimonK deposited directly on NiF 17.2 m(2) g(-1). Electrochemical measurements demonstrated that the NiF-G/SimonK composite exhibit a high specific capacitance of 836 F g(-1) at a current density of 1 A g(-1), and excellent rate capability and cycling stability with capacitance retention of 92% after 5000 charge/discharge cycles. PMID:26397922

  4. High-performance binder-free supercapacitor electrode by direct growth of cobalt-manganese composite oxide nansostructures on nickel foam

    PubMed Central

    2014-01-01

    A facile approach composed of hydrothermal process and annealing treatment is proposed to directly grow cobalt-manganese composite oxide ((Co,Mn)3O4) nanostructures on three-dimensional (3D) conductive nickel (Ni) foam for a supercapacitor electrode. The as-fabricated porous electrode exhibits excellent rate capability and high specific capacitance of 840.2 F g-1 at the current density of 10 A g-1, and the electrode also shows excellent cycling performance, which retains 102% of its initial discharge capacitance after 7,000 cycles. The fabricated binder-free hierarchical composite electrode with superior electrochemical performance is a promising candidate for high-performance supercapacitors. PMID:25258611

  5. Three-dimensional porous bioscaffolds for bone tissue regeneration: fabrication via adaptive foam reticulation and freeze casting techniques, characterization, and cell study.

    PubMed

    Mallick, Kajal K; Winnett, James; van Grunsven, William; Lapworth, James; Reilly, Gwendolen C

    2012-11-01

    Highly interconnected and 3D porous bioactive hydroxyapatite (HAP) and Bioglass scaffolds have been fabricated by an adaptive version of camphene based foam reticulation (ARM) and camphene freeze casting (CFC) methods. Controlled sublimation of camphene during freeze casting at -78°C produced process optimized bioscaffolds with open, uniform, and interconnected porous structures. HAP and Bioglass scaffolds with desired porosity, pore size, and microtopography were successfully fabricated using polyurethane foam templates of appropriate structures. Macropores of 50-1100 μm with microporosity of 1-10 μm, known to facilitate cell adhesion and proliferation, were obtained. Compressive yield strength of 0.8 MPa close to the upper range of cancellous bone was achieved. The mean compressive strength of HAP scaffolds compared favorably with the theoretical model of porosity variation with strength and was higher than reported values. The nature of pore development, morphology, porosity, crystal structure, chemical composition, and thermal behavior were characterized using scanning electron and optical microscopy, X-ray diffraction, thermal analysis, and mercury porosimetry. These scaffolds are suited for nonstructural graft and were not cytotoxic in vitro when osteoblast-like MG63 cells were cultured with the HAP constructs. The cells attached indicated by cell metabolic activity by resazurin assay and spread well when cultured on the surface of the materials. PMID:22696264

  6. Donut-shaped Co3O4 nanoflakes grown on nickel foam with enhanced supercapacitive performances

    NASA Astrophysics Data System (ADS)

    Han, Zhicheng; Zheng, Xin; Yao, Shunyu; Xiao, Huanhao; Qu, Fengyu; Wu, Xiang

    2016-03-01

    Donut-shaped Co3O4 nanoflakes grown on nickel foam were successfully fabricated by a simple one-pot hydrothermal approach. The prepared products were functionalized as the supercapacitors electrodes. Electrochemical performance of the as-prepared products demonstrated high specific capacitance (518 mF cm-2) and excellent cycling stability (∼25% loss) after 6000 repetitive cycles at a charge-discharge current density of 1 mA cm-2. The superior electrochemical performance may be ascribed into two reasons: one is the unique spatial structures which possess many active sites and provide enhanced combination between the electrode and nickel foam to support fast ion and electron transfer, the other is that donut-shaped Co3O4 nanoflakes electrodes show relatively lower resistances. It is expected that the as-obtained donut-shaped Co3O4 nanoflakes could have potential applications in portable electronics and electrical vehicles.

  7. Hierarchical Assembly of Tungsten Spheres and Epoxy Composites in Three-Dimensional Graphene Foam and Its Enhanced Acoustic Performance as a Backing Material.

    PubMed

    Qiu, Yunfeng; Liu, Jingjing; Lu, Yue; Zhang, Rui; Cao, Wenwu; Hu, PingAn

    2016-07-20

    Backing materials play important role in enhancing the acoustic performance of an ultrasonic transducer. Most backing materials prepared by conventional methods failed to show both high acoustic impedance and attenuation, which however determine the bandwidth and axial resolution of acoustic transducer, respectively. In the present work, taking advantage of the structural feature of 3D graphene foam as a confined space for dense packing of tungsten spheres with the assistance of centrifugal force, the desired structural requirement for high impedance is obtained. Meanwhile, superior thermal conductivity of graphene contributes to the acoustic attenuation via the conversion of acoustic waves to thermal energy. The tight contact between tungstate spheres, epoxy matrix, or graphene makes the acoustic wave depleted easily for the absence of air barrier. The as-prepared 3DG/W80 wt %/epoxy film in 1 mm, prepared using ∼41 μm W spheres in diameter, not only displays acoustic impedance of 13.05 ± 0.11 MRayl but also illustrates acoustic attenuation of 110.15 ± 1.23 dB/cm MHz. Additionally, the composite film exhibits a high acoustic absorption coefficient, which is 94.4% at 1 MHz and 100% at 3 MHz, respectively. Present composite film outperforms most of the reported backing materials consisting of metal fillers/polymer blending in terms of the acoustic impedance and attenuation. PMID:27352024

  8. Ni foam supported three-dimensional vertically aligned and networked layered CoO nanosheet/graphene hybrid array as a high-performance oxygen evolution electrode

    NASA Astrophysics Data System (ADS)

    Yuan, Weiyong; Zhao, Ming; Yuan, Jia; Li, Chang Ming

    2016-07-01

    The sluggish oxygen evolution reaction (OER) represents a major kinetic bottleneck in water splitting. Herein we report the synthesis of a novel Ni foam (NF) supported 3-D vertically aligned and interconnected layered CoO nanosheet array with controlled density, layer thickness, and interlayer spacing, and the conformal self-assembly of graphene on this nanosheet array. The obtained CoO layered nanosheet/graphene hybrid nanoarray was directly used as an OER electrode, showing a current density of 10 mA cm-2 at an overpotential of 330 mV and a Tafel slope of 79 mV dec-1, both of which are much lower than pristine NF and the nanosheet array without graphene, and are among the lowest reported for Co-based OER catalysts and transition metal oxide-based ones measured under the same conditions. In addition, it can retain 92.4% of the current density after 66 h of chronoamperometry testing at a potential of 1.0 V vs. SCE, and 94.3% of the current density at 1.0 V vs. SCE after 200 cyclic voltammetry cycles (0-1.0 V vs. SCE). The excellent catalytic activity and stability toward OER are ascribed to the 3-D NF supported robustly grown networked layered nanosheet array structure and the synergistic effects between CoO layered nanosheets and graphene.

  9. Aluminium Foams Fabricated by the PM Route using Nickel-coated Titanium Hydride Powders of Controlled Particle Size

    NASA Astrophysics Data System (ADS)

    Proa-Flores, Paula Mercedes

    To establish the effect of reducing the temperature mismatch between the TiH2 decomposition temperature and the aluminium melting point on the foams morphological features and their mechanical compression behavior, a nickel coating on TiH2 powders was used as a hydrogen diffusion barrier and the size of TiH2 powders was controlled to modify the hydrogen evolution temperature. The nickel diffusion barrier was produced by an electroless deposition technique and the hydrogen evolution behavior of coated powders was investigated by thermogravimetrical analysis. The effect of particle size was determined with powders of five particle size fractions along with powders of different particle size obtained from a supplier. Foamable precursors were obtained by hot pressing a mix of aluminium powders with 1 wt.% of TiH2 powders and foams were fabricated at 750 and 800 °C. The foams mechanical strength was investigated by uni-axial compression on foam cylinders with and without outer skin. Coating produced a continuous and homogeneous deposit of 96.5 wt.% nickel and reduced the initial temperature mismatch by approximately 70°C. Additionally, the coating adhesion proved to be good enough to withstand the mixing and compaction processes. Nickel-coated TiH2 powders generated foams with a more homogeneous and reproducible pore structure than foams produced with powders in the as-received and passivated condition. On the other hand, the hydrogen evolution onset of TiH2 shifted towards higher temperatures as the particle size increased. The particle size influenced the foam expansion and the porosity features. Powders of larger particle size produced foams with a more uniform pore distribution and size. Finally, compression tests on skinless foams containing nickel displayed quasi-horizontal energy regimes with longer stroke lengths than the rest, however the final energy absorption efficiencies (above 7.2 kJ·kg-1) were not remarkably increased.

  10. Three-dimensional nitrogen-doped graphene as an ultrasensitive electrochemical sensor for the detection of dopamine.

    PubMed

    Feng, Xiaomiao; Zhang, Yu; Zhou, Jinhua; Li, Yi; Chen, Shufen; Zhang, Lei; Ma, Yanwen; Wang, Lianhui; Yan, Xiaohong

    2015-02-14

    Three-dimensional nitrogen-doped graphene (3D N-doped graphene) was prepared through chemical vapor deposition (CVD) by using porous nickel foam as a substrate. As a model, a dopamine biosensor was constructed based on the 3D N-doped graphene porous foam. Electrochemical experiments exhibited that this biosensor had a remarkable detection ability with a wide linear detection range from 3 × 10(-6) M to 1 × 10(-4) M and a low detection limit of 1 nM. Moreover, the fabricated biosensor also showed an excellent anti-interference ability, reproducibility, and stability. PMID:25565111

  11. Three-dimensional nitrogen-doped graphene as an ultrasensitive electrochemical sensor for the detection of dopamine

    NASA Astrophysics Data System (ADS)

    Feng, Xiaomiao; Zhang, Yu; Zhou, Jinhua; Li, Yi; Chen, Shufen; Zhang, Lei; Ma, Yanwen; Wang, Lianhui; Yan, Xiaohong

    2015-01-01

    Three-dimensional nitrogen-doped graphene (3D N-doped graphene) was prepared through chemical vapor deposition (CVD) by using porous nickel foam as a substrate. As a model, a dopamine biosensor was constructed based on the 3D N-doped graphene porous foam. Electrochemical experiments exhibited that this biosensor had a remarkable detection ability with a wide linear detection range from 3 × 10-6 M to 1 × 10-4 M and a low detection limit of 1 nM. Moreover, the fabricated biosensor also showed an excellent anti-interference ability, reproducibility, and stability.

  12. High-yield growth of carbon nanofilaments on nickel foam using nickel-tin intermetallic catalysts.

    PubMed

    Jeong, Namjo; Hwang, Kyo Sik; Yang, Seung Cheol

    2014-10-01

    The integration of nanomaterials into macroscopic structures is of importance to their practical use. We report the direct synthesis of carbon nanofilaments on Ni foam using Ni-Sn intermetallic nanoparticles. The use of SnO2 nanoparticles was highly effective for the high-yield growth of carbon nanofilaments without the occurrence of surface breakup, resulting from excessive carbon accumulation in the Ni foam. Carbon nanofilaments with a diameter of 50 nm were synthesized and contained Ni3Sn nanoparticles at the tip, indicating a tip-growth mechanism. Higher vacuum conditions led to the growth of highly crystalline carbon nanofilaments. The results obtained using different sources of hydrocarbon revealed that in contrast to C2H2, CH4 or C3H8 did not induce carbon nanofilament formation on Ni foam. PMID:25942857

  13. Three-dimensional aluminum foam/carbon nanotube scaffolds as long- and short-range electron pathways with improved sulfur loading for high energy density lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Cheng, Xin-Bing; Peng, Hong-Jie; Huang, Jia-Qi; Zhu, Lin; Yang, Shu-Hui; Liu, Yuan; Zhang, Hua-Wei; Zhu, Wancheng; Wei, Fei; Zhang, Qiang

    2014-09-01

    Conductive carbon scaffolds are efficient and effective to build advanced carbon/sulfur composite cathodes for lithium-sulfur (Li-S) batteries. However, the areal sulfur loading is commonly less than 4.0 mg cm-2, which limits the energy density and practical application of Li-S cells. In this contribution, three-dimensional (3D) aluminum foam/carbon nanotube (CNT) scaffolds were applied as the current collectors to build long- and short-range electron pathways and provided enough space for high sulfur loading. The sulfur loading amount on the 3D current collectors ranged from 7.0 to 12.5 mg cm-2. A high initial discharge capacity of 6.02 mAh cm-2 (860 mAh g-1) was achieved on an electrode with an improved sulfur loading of 7.0 mg cm-2. Therefore, the combination of 3D long-range current collectors and short-range CNT conductive scaffold provides an efficient and effective route to make full use of sulfur with a very high sulfur loading amount in a Li-S cell.

  14. NiCo2S4 nanotube arrays grown on flexible nitrogen-doped carbon foams as three-dimensional binder-free integrated anodes for high-performance lithium-ion batteries.

    PubMed

    Wu, Xiaoyu; Li, Songmei; Wang, Bo; Liu, Jianhua; Yu, Mei

    2016-02-14

    Binary metal sulfides, especially NiCo2S4, hold great promise as anode materials for high-performance lithium-ion batteries because of their excellent electronic conductivity and high capacity compared to mono-metal sulfides and oxides. Here, NiCo2S4 nanotube arrays are successfully grown on flexible nitrogen-doped carbon foam (NDCF) substrates with robust adhesion via a facile surfactant-assisted hydrothermal route and the subsequent sulfurization treatment. The obtained NiCo2S4/NDCF composites show unique three-dimensional architectures, in which NiCo2S4 nanotubes of ∼5 μm in length and 100 nm in width are uniformly grown on the NDCF skeletons to form arrays. When used directly as integrated anodes for lithium-ion batteries without any conductive additives and binders, the NiCo2S4/NDCF composites exhibit a high reversible capacity of 1721 mA h g(-1) at a high current density of 500 mA g(-1), enhanced cycling performance with the capacity maintained at 1182 mA h g(-1) after 100 cycles, and a remarkable rate capability. The excellent lithium storage performances of the composites could be attributed to the unique material composition, a rationally designed hollow nanostructure and an integrated smart architecture, which offer fast electron transport and ion diffusion, enhanced material/-electrolyte contact area and facile accommodation of strains during the lithium insertion and extraction process. PMID:26796603

  15. High-Loading Nickel Cobaltate Nanoparticles Anchored on Three-Dimensional N-Doped Graphene as an Efficient Bifunctional Catalyst for Lithium-Oxygen Batteries.

    PubMed

    Gong, Hao; Xue, Hairong; Wang, Tao; Guo, Hu; Fan, Xiaoli; Song, Li; Xia, Wei; He, Jianping

    2016-07-20

    The lithium-oxygen batteries have been considered as the progressive energy storage equipment for their expected specific energy. To improve the electrochemical catalytic performance in the lithium-oxygen batteries, the NiCo2O4 nanoparticles (NCONPs) are firmly anchored onto the surface of the N-doped reduced graphene oxide (N-rGO) by the hydrothermal method followed by low-temperature calcination. Compared with the pure metallic oxide, the introduction of the rGO can create the high surface area, which give a good performance for ORR (oxygen reduction reaction), and improve the electrical conductivity between the NCONPs. The high-loading NCONPs also ensure the material to have great catalytic activity for OER (oxygen evolution reaction), and the rGO can be protected by the nanoparticles coating against the side reaction with the Li2O2. The as-synthesized NCO@N-rGO composites deliver a specific surface area (about 242.5 m(2) g(-1)), exhibiting three-dimensional (3D) porous structure, which provides a large passageway for the diffusion of the oxygen and benefits the infiltration of electrolyte and the storage of the discharge products. Owing to these special architectures features and intrinsic materials, the NCO@N-rGO cathode delivers a high specific capacity (6716 mAh g(-1)), great rate performance, and excellent cycling stability with cutoff capacity of 1000 mAh g(-1) (112 cycles) in the lithium-oxygen batteries. The improved electrochemical catalytic activity and the special 3D porous structure make the NCO@N-rGO composites be a promising candidate for Li-O2 batteries. PMID:27353228

  16. Electrodeposition of palladium and reduced graphene oxide nanocomposites on foam-nickel electrode for electrocatalytic hydrodechlorination of 4-chlorophenol.

    PubMed

    Liu, Yong; Liu, Lan; Shan, Jun; Zhang, Jingdong

    2015-06-15

    A high-performance palladium (Pd) and reduced graphene oxide (RGO) composite electrode was prepared on foam-nickel (foam-Ni) via two-step electrodeposition processes. The scanning electron microscopic (SEM) observation showed that the obtained Pd/RGO/foam-Ni composite electrode displayed a uniform and compact morphology. The X-ray diffraction (XRD) and X-ray photoelectron spectroscopic (XPS) analysis confirmed the successful deposition of Pd and RGO on nickel substrate. The cyclic voltammetric (CV) measurements indicated that the presence of RGO greatly enhanced the active surface area of Pd particles deposited on foam-Ni. The as-deposited Pd/RGO/foam-Ni electrode was applied to electrocatalytic hydrodechlorination (ECH) of 4-chlorophenol (4-CP). Various factors influencing the dechlorination of 4-CP such as dechlorination current, initial concentration of 4-CP, Na2SO4 concentration and initial pH were systematically investigated. The thermodynamic analysis showed that the dechlorination reaction of 4-CP at different temperatures followed the first-order kinetics and the activation energy for 4-CP dechlorination on Pd/RGO/foam-Ni electrode was calculated to be 51.96 kJ mol(-1). Under the optimum conditions, the dechlorination efficiency of 4-CP could reach 100% after 60-min ECH treatment. Moreover, the prepared Pd/RGO/foam-Ni composite electrode showed good stability for recycling utilization in ECH of 4-CP. PMID:25731146

  17. Nickel foam-based manganese dioxide-carbon nanotube composite electrodes for electrochemical supercapacitors

    NASA Astrophysics Data System (ADS)

    Li, Jun; Yang, Quan Min; Zhitomirsky, Igor

    Manganese dioxide nanofibers with length ranged from 0.1 to 1 μm and a diameter of about 2-4 nm were prepared by a chemical precipitation method. Composite electrodes for electrochemical supercapacitors were fabricated by impregnation of slurries of the manganese dioxide nanofibers and multiwalled carbon nanotubes (MWCNTs) into porous nickel foam current collectors. In the composite electrodes, MWCNT formed a secondary conductivity network within the nickel foam cells. Obtained composite electrodes, containing 0-20 wt.% MWCNT with total mass loading of 40 mg cm -2, showed a capacitive behavior in the 0.1-0.5 M Na 2SO 4 solutions. The highest specific capacitance (SC) of 155 F g -1 was obtained at a scan rate of 2 mV s -1 in the 0.5 M Na 2SO 4 solutions. The SC increased with increasing MWCNT content in the composite materials and increasing Na 2SO 4 concentration in the solutions and decreased with increasing scan rate.

  18. Electrocatalytic hydrodechlorination of 4-chlorobiphenyl in aqueous solution using palladized nickel foam cathode.

    PubMed

    Yang, Bo; Yu, Gang; Shuai, Danmeng

    2007-04-01

    The electrocatalytic hydrodechlorination of 4-chlorobiphenyl on palladized nickel foam with high porous structure in an aqueous solution containing MeOH, bromide of hexadecyltrimethylammonium (CTAB), sodium acetate, and acetic acid were investigated in a membrane-separated flow-through cell. The Pd/Ni foam electrode was prepared by electroless deposition method, on which the Pd particles dispersed finely over Ni foam surface indicated by SEM-EDX analysis. The effects of current density, organic cosolvent, initial concentration, temperature, and flow rate on the hydrodechlorination of 4-chlorobiphenyl were examined. Methanol was among the best cosolvents and was used in preferential concentration of 50 vol%. Moderate current density (e.g., 2.23 mA cm(-2)), relatively high initial concentration, temperature, and flow rate were beneficial to improve the hydrodechlorination of 4-chlorobiphenyl. The current efficiencies for the conversion of 1mM 4-MCB decreased with increasing current density and range from 37.2% at 0.74 mA cm(-2) to 14.1% at 5.21 mA cm(-2) after 20 min electrolysis cut. Under the optimized conditions, 1mM of 4-MCB could be removed rapidly with the rate of 94.6% after 2h electrolysis, which gave current efficiencies and energy consumptions in range of 8.1-24.6% and 1.7-5.2 kW h kg(-1), respectively. PMID:17141295

  19. Three-dimensional sonoembryology.

    PubMed

    Benoit, Bernard; Hafner, Tomislav; Kurjak, Asim; Kupesić, Sanja; Bekavac, Ivanka; Bozek, Tomislav

    2002-01-01

    Three-dimensional (3D) ultrasound plays an important role in obstetrics, predominantly for assessing fetal anatomy. Presenting volume data in a standard anatomic orientation valuably assists both ultrasonographers and pregnant patients to recognize the anatomy more readily. Three-dimensional ultrasound is advantageous in studying normal embryonic and/or fetal development, as well as providing information for families at risk for specific congenital anomalies by confirming normality. This method offers advantages in assessing the embryo in the first trimester due to its ability to obtain multiplanar images through endovaginal volume acquisition. Rotation allows the systematic review of anatomic structures and early detection of fetal anomalies. Three-dimensional ultrasound imaging in vivo compliments pathologic and histologic evaluation of the developing embryo, giving rise to a new term: 3D sonoembryology. Rapid technological development will allow real-time 3D ultrasound to provide improved and expanded patient care on the one side, and increased knowledge of developmental anatomy on the other. PMID:11933658

  20. Moment invariants for two-dimensional and three-dimensional characterization of the morphology of gamma-prime precipitates in nickel-base superalloys

    NASA Astrophysics Data System (ADS)

    Macsleyne, Jeremiah P.

    The relation between microstructural features and a material's properties is central to materials science. Certain morphological features of a microstructure can only be determined by 3-D characterization techniques, e.g. the connectivity of precipitates, and the true precipitate shape; others require geometric assumptions for stereological estimates, e.g. precipitate size distribution and the number of precipitates. When these inherently 3-D features affect the properties of a specific material, experimental techniques are necessary to investigate the 3-D nature of the microstructure, and to provide a more complete microstructural characterization. The quantitative description of 2-D and 3-D shapes is of fundamental importance to microstructural characterization. One approach to describing a microstructure is to characterize the shapes of individual precipitates. This characterization has typically been limited to particle size, aspect-ratio, and other qualitative descriptors. In general, these are insufficient and do not provide an adequate characterization in a way that allows for a direct comparison between different microstructures. This is evident during microstructure evolution when changes in precipitate morphology occur or when precipitates exhibit complex shapes. In this thesis, we show how moment invariants (combinations of second order moments that are invariant w.r.t. affine or similarity transformations) can be used as sensitive shape discriminators in 2-D and 3-D. This work focuses on the characterization of the two phase microstructure of nickel base superalloys and specically the gamma-prime (Ni3Al) precipitate morphology. Experimental data is collected by means of automated Focused-Ion Beam (FIB) based serial sectioning. Techniques for automated image processing and segmentation are developed which allow for direct conversion of raw serial-sectioning data to 3-D microstructural data. The gamma-prime precipitate morphology is characterized using

  1. The Evolution of Solid Oxide Fuel Cell Nickel-Yttria Stabilized Zirconia Anodes Studied Using Electrochemical and Three-Dimensional Microstructural Characterizations

    NASA Astrophysics Data System (ADS)

    Kennouche, David O.

    This thesis focuses on Solid Oxide Fuel Cells (SOFCs). The 21st century will see major changes in the way energy is produced, stored, and used around the world. SOFCs, which provide an efficient, scalable, and low-pollution alternative method for electricity generation, are expected to play an important role. SOFCs can also be operated in electrolysis mode for energy storage, important since health and economic reasons are causing a shift towards intermittent renewable energy resources. However, multiple limitations mainly linked to cost and durability have prevented the expansion of this technology to mass markets. This work focuses on the Nickel - Yttria Stabilized Zirconia (Ni-YSZ) anode that is widely used in SOFCs. Coarsening of Ni in the Ni-YSZ anode has been widely cited as a primary cause of long-term SOFC degradation. While there have been numerous studies of Ni coarsening reported, these have typically only tracked the evolution of Ni particle size, not the entire microstructure, and have typically not been correlated directly with electrochemical performance. In this thesis, the advanced tomography techniques Focused Ion Beam - Scanning Electron Microscopy (FIB-SEM) tomography and Trans- mission X-ray Microscopy (TXM) have been utilized to enable insight into the evolution of Ni-YSZ structure and how it relates to performance degradation. Extensive anode aging studies were done for relatively short times using temperatures higher than in normal SOFC operation in order to accelerate microstructural evolution. In addition the microstructure changes were correlated with changes in anode polarization resistance. While most of the measurements were done by comparing different anodes aged under different conditions, the first example of a "pseudo in situ" measurement where the same anode was 3D imaged repeatedly with intervening aging steps, was also demonstrated. A microstructural evolution model that focuses on the active three-phase boundary density was

  2. Layered manganese oxides-decorated and nickel foam-supported carbon nanotubes as advanced binder-free supercapacitor electrodes

    NASA Astrophysics Data System (ADS)

    Huang, Ming; Mi, Rui; Liu, Hao; Li, Fei; Zhao, Xiao Li; Zhang, Wei; He, Shi Xuan; Zhang, Yu Xin

    2014-12-01

    Three-dimensional carbon nanotubes@MnO2 core-shell nanostructures grown on Ni foam for binder-free capacitor electrodes have been fabricated by a floating catalyst chemical vapor deposition process and a facile hydrothermal approach. Ultrathin layered MnO2 nanosheets are uniformly coated on the surface of the carbon nanotubes (CNTs), directly grown on Ni foam. This unique well-designed binder-free electrode exhibits a high specific capacitance (325.5 F g-1 at a current density of 0.3 A g-1), good rate capability (70.7% retention), and excellent cycling stability (90.5% capacitance retention after 5000 cycles), due to the high conductivity of the close contact between CNTs and Ni foam, as well as the moderate specific surface area of the CNTs@MnO2 core-shell nanostructures. The developed synthetic strategy may provide design guidelines for constructing advanced binder-free supercapacitors electrode.

  3. Three-dimensional metamaterials

    DOEpatents

    Burckel, David Bruce

    2012-06-12

    A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.

  4. Three Dimensional Dirac Semimetals

    NASA Astrophysics Data System (ADS)

    Zaheer, Saad

    2014-03-01

    Dirac points on the Fermi surface of two dimensional graphene are responsible for its unique electronic behavior. One can ask whether any three dimensional materials support similar pseudorelativistic physics in their bulk electronic spectra. This possibility has been investigated theoretically and is now supported by two successful experimental demonstrations reported during the last year. In this talk, I will summarize the various ways in which Dirac semimetals can be realized in three dimensions with primary focus on a specific theory developed on the basis of representations of crystal spacegroups. A three dimensional Dirac (Weyl) semimetal can appear in the presence (absence) of inversion symmetry by tuning parameters to the phase boundary separating a bulk insulating and a topological insulating phase. More generally, we find that specific rules governing crystal symmetry representations of electrons with spin lead to robust Dirac points at high symmetry points in the Brillouin zone. Combining these rules with microscopic considerations identifies six candidate Dirac semimetals. Another method towards engineering Dirac semimetals involves combining crystal symmetry and band inversion. Several candidate materials have been proposed utilizing this mechanism and one of the candidates has been successfully demonstrated as a Dirac semimetal in two independent experiments. Work carried out in collaboration with: Julia A. Steinberg, Steve M. Young, J.C.Y. Teo, C.L. Kane, E.J. Mele and Andrew M. Rappe.

  5. Three dimensional interactive display

    NASA Technical Reports Server (NTRS)

    Vranish, John M. (Inventor)

    2005-01-01

    A three-dimensional (3-D) interactive display and method of forming the same, includes a transparent capaciflector (TC) camera formed on a transparent shield layer on the screen surface. A first dielectric layer is formed on the shield layer. A first wire layer is formed on the first dielectric layer. A second dielectric layer is formed on the first wire layer. A second wire layer is formed on the second dielectric layer. Wires on the first wire layer and second wire layer are grouped into groups of parallel wires with a turnaround at one end of each group and a sensor pad at the opposite end. An operational amplifier is connected to each of the sensor pads and the shield pad biases the pads and receives a signal from connected sensor pads in response to intrusion of a probe. The signal is proportional to probe location with respect to the monitor screen.

  6. Highly porous nickel@carbon sponge as a novel type of three-dimensional anode with low cost for high catalytic performance of urea electro-oxidation in alkaline medium

    NASA Astrophysics Data System (ADS)

    Ye, Ke; Zhang, Dongming; Guo, Fen; Cheng, Kui; Wang, Guiling; Cao, Dianxue

    2015-06-01

    Highly porous nickel@carbon sponge electrode with low cost is synthesized via a facile sponge carbonization method coupled with a direct electrodeposition of Ni. The obtained electrodes are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). The catalytic performances of urea electro-oxidation in alkaline medium are investigated by cyclic voltammetry (CV) and chronoamperometry (CA). The Ni@carbon sponge electrode exhibits three-dimensional open network structures with a large surface area. Remarkably, the Ni@carbon sponge electrode shows much higher electrocatalytic activity and lower onset oxidation potential towards urea electro-oxidation compared to a Ni/Ti flat electrode synthesized by the same procedure. The Ni@carbon sponge electrode achieves an onset oxidation potential of 0.24 V (vs. Ag/AgCl) and a peak current density of 290 mA cm-2 in 5 mol L-1 NaOH and 0.10 mol L-1 urea solutions accompanied with a desirable stability. The impressive electrocatalytic activity is largely attributed to the high intrinsic electronic conductivity, superior porous network structures and rich surface Ni active species, which can largely boost the interfacial electroactive sites and charge transfer rates for urea electro-oxidation in alkaline medium, indicating promising applications in fuel cells.

  7. Electrodeposition of palladium on carbon nanotubes modified nickel foam as an efficient electrocatalyst towards hydrogen peroxide reduction

    NASA Astrophysics Data System (ADS)

    Yang, Fan; Cao, Bo; Tao, Yue; Hu, Miao; Feng, Chengcheng; Wang, Lei; Jiang, Zhao; Cao, Dianxue; Zhang, Ying

    2015-12-01

    In this article, a three-dimensional electrode (Pd-CNT/Ni foam) based on Pd nanoparticles and carbon nanotubes (CNTs) is successfully developed by a simple "dipping and drying" process and a potentiostatic deposition technology for H2O2 reduction in base medium. The composition and structure of Pd-CNT/Ni foam electrode are examined by X-ray diffractometer, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, respectively. The cyclic voltammetry (CV) and chronoamperometry (CA) techniques are applied to determine the electrochemical performance. The electrode exhibits a high catalytic activity for H2O2 electroreduction, and it outperforms Pd/Ni foam electrode without CNT coating. At the reduction potential of -0.8 V, the reduction currents on Pd-CNT/Ni foam electrode can reach 323 mA cm-2, however, it is only 192 mA cm-2 on Pd/Ni foam electrode, which is increased by 68.2%. The impressive electrocatalytic performance is largely attributed to the superior open structure and high electronic conductivity, which allows the high utilization of Pd surfaces and makes the electrode have higher electrochemical activity. These findings may provide the opportunity on preparing binder-free carbon-supported electrode in the application of fuel cells.

  8. Highly cytocompatible and flexible three-dimensional graphene/polydimethylsiloxane composite for culture and electrochemical detection of L929 fibroblast cells.

    PubMed

    Waiwijit, Uraiwan; Maturos, Thitima; Pakapongpan, Saithip; Phokharatkul, Ditsayut; Wisitsoraat, Anurat; Tuantranont, Adisorn

    2016-08-01

    Recently, three-dimensional graphene interconnected network has attracted great interest as a scaffold structure for tissue engineering due to its high biocompatibility, high electrical conductivity, high specific surface area and high porosity. However, free-standing three-dimensional graphene exhibits poor flexibility and stability due to ease of disintegration during processing. In this work, three-dimensional graphene is composited with polydimethylsiloxane to improve the structural flexibility and stability by a new simple two-step process comprising dip coating of polydimethylsiloxane on chemical vapor deposited graphene/Ni foam and wet etching of nickel foam. Structural characterizations confirmed an interconnected three-dimensional multi-layer graphene structure with thin polydimethylsiloxane scaffold. The composite was employed as a substrate for culture of L929 fibroblast cells and its cytocompatibility was evaluated by cell viability (Alamar blue assay), reactive oxygen species production and vinculin immunofluorescence imaging. The result revealed that cell viability on three-dimensional graphene/polydimethylsiloxane composite increased with increasing culture time and was slightly different from a polystyrene substrate (control). Moreover, cells cultured on three-dimensional graphene/polydimethylsiloxane composite generated less ROS than the control at culture times of 3-6 h. The results of immunofluorescence staining demonstrated that fibroblast cells expressed adhesion protein (vinculin) and adhered well on three-dimensional graphene/polydimethylsiloxane surface. Good cell adhesion could be attributed to suitable surface properties of three-dimensional graphene/polydimethylsiloxane with moderate contact angle and small negative zeta potential in culture solution. The results of electrochemical study by cyclic voltammetry showed that an oxidation current signal with no apparent peak was induced by fibroblast cells and the oxidation current at an

  9. Foam

    NASA Astrophysics Data System (ADS)

    Cornick, Marc

    Phenolic foam is a unique cellular material that can be utilized in either a fully open cell structure or a completely closed cell structure in a diversity of applications such as open cellular material for floral foam, soil propagation media and/or orthopedic use, and closed cell phenolic foam primarily for thermal insulation. Thus, phenolic foam is much more versatile than other competitive organic foams such as polystyrene and polyurethane with the latter materials being more heavily involved in thermal insulation. Foam processing can consider batch, semi-continuous, or continuous conditions, and the features and weaknesses of the appropriate processes are discussed along with continuous mix heads involving high and low pressure conditions.

  10. Three dimensional Dirac semimetals

    NASA Astrophysics Data System (ADS)

    Zaheer, Saad

    We extend the physics of graphene to three dimensional systems by showing that Dirac points can exist on the Fermi surface of realistic materials in three dimensions. Many of the exotic electronic properties of graphene can be ascribed to the pseudorelativistic behavior of its charge carriers due to two dimensional Dirac points on the Fermi surface. We show that certain nonsymmorphic spacegroups exhibit Dirac points among the irreducible representations of the appropriate little group at high symmetry points on the surface of the Brillouin zone. We provide a list of all Brillouin zone momenta in the 230 spacegroups that can host Dirac points. We describe microscopic considerations necessary to design materials in one of the candidate spacegroups such that the Dirac point appears at the Fermi energy without any additional non-Dirac-like Fermi pockets. We use density functional theory based methods to propose six new Dirac semimetals: BiO 2 and SbO2 in the beta-cristobalite lattice (spacegroup 227), and BiCaSiO4, BiMgSiO4, BiAlInO 4, and BiZnSiO4 in the distorted spinels lattice (spacegroup 74). Additionally we derive effective Dirac Hamiltonians given group representative operators as well as tight binding models incorporating spin-orbit coupling. Finally we study the Fermi surface of zincblende (spacegroup 216) HgTe which is effectively point-like at Gamma in the Brillouin zone and exhibits accidental degeneracies along a threefold rotation axis. Whereas compressive strain gaps the band structure into a topological insulator, tensile strain shifts the accidental degeneracies away from Gamma and enlarges the Fermi surface. States on the Fermi surface exhibit nontrivial spin texture marked by winding of spins around the threefold rotation axis and by spin vortices indicating a change in the winding number. This is confirmed by microscopic calculations performed in tensile strained HgTe and Hg0.5Zn 0.5 Te as well as k.p theory. We conclude with a summary of recent

  11. The key role of dislocation dissociation in the plastic behaviour of single crystal nickel-based superalloy with low stacking fault energy: Three-dimensional discrete dislocation dynamics modelling

    NASA Astrophysics Data System (ADS)

    Huang, Minsheng; Li, Zhenhuan

    2013-12-01

    To model the deformation of single crystal nickel based superalloys (SCNBS) with low stacking fault energy (SFE), three-dimensional discrete dislocation dynamics (3D-DDD) is extended by incorporating dislocation dissociation mechanism. The present 3D-DDD simulations show that, consistent with the existing TEM observation, the leading partial can enter the matrix channel efficiently while the trailing partial can hardly glide into it when the dislocation dissociation is taken into account. To determine whether the dislocation dissociation can occur or not, a critical percolation stress (CPS) based criterion is suggested. According to this CPS criterion, for SCNBS there exists a critical matrix channel width. When the channel width is lower than this critical value, the dislocation tends to dissociate into an extended configuration and vice versa. To clarify the influence of dislocation dissociation on CPS, the classical Orowan formula is improved by incorporating the SFE. Moreover, the present 3D-DDD simulations also show that the yielding stress of SCNBSs with low SFE may be overestimated up to 30% if the dislocation dissociation is ignored. With dislocation dissociation being considered, the size effect due to the width of γ matrix channel and the length of γ‧ precipitates on the stress-strain responses of SCNBS can be enhanced remarkably. In addition, due to the strong constraint effect by the two-phase microstructure in SCNBS, the configuration of formed junctions is quite different from that in single phase crystals such as Cu. The present results not only provide clear understanding of the two-phase microstructure levelled microplastic mechanisms in SCNBSs with low SFE, but also help to develop new continuum-levelled constitutive laws for SCNBSs.

  12. Nickel nanoparticles embedded in carbon foam for improving electromagnetic shielding effectiveness

    NASA Astrophysics Data System (ADS)

    Kumar, Rajeev; Kumari, Saroj; Dhakate, Sanjay R.

    2014-08-01

    To improve electromagnetic shielding effectiveness of light weight carbon foam (CF), magnetic nanoparticles were embedded in it during processing. The CF was developed from the coal tar pitch and mixture of coal tar pitch-Nickel (Ni) nanoparticles by sacrificial template technique and heat treated to up 1,000 °C. To ascertain the effect of Ni nanoparticles embedded in CF, it was characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, vector network analyzer and vibration sample magnetometer. It is observed that Ni nanoparticles embedded in the carbon material play an important role for improving the structure and electrical conductivity of CF-Ni by catalytic carbonization. The structural investigation suggests that the Ni nanoparticles embedded in the carbon material in bulk as well on the surface of CF. The CF demonstrates excellent shielding response in the frequency range 8.2-12.4 GHz in which total shielding effectiveness (SE) dominated by absorption losses. The total SE is -25 and -61 dB of CF and CF-Ni, it is governed by absorption losses -48.5 dB in CF-Ni. This increase is due to the increase in dielectric and magnetic losses of ferromagnetic Ni nanoparticles with high surface area. Thus, light weight CF embedded with small amount of magnetic nanoparticles can be useful material for stealth technology.

  13. Nickel nanoparticles embedded in carbon foam for improving electromagnetic shielding effectiveness

    NASA Astrophysics Data System (ADS)

    Kumar, Rajeev; Kumari, Saroj; Dhakate, Sanjay R.

    2015-06-01

    To improve electromagnetic shielding effectiveness of light weight carbon foam (CF), magnetic nanoparticles were embedded in it during processing. The CF was developed from the coal tar pitch and mixture of coal tar pitch-Nickel (Ni) nanoparticles by sacrificial template technique and heat treated to up 1,000 °C. To ascertain the effect of Ni nanoparticles embedded in CF, it was characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, vector network analyzer and vibration sample magnetometer. It is observed that Ni nanoparticles embedded in the carbon material play an important role for improving the structure and electrical conductivity of CF-Ni by catalytic carbonization. The structural investigation suggests that the Ni nanoparticles embedded in the carbon material in bulk as well on the surface of CF. The CF demonstrates excellent shielding response in the frequency range 8.2-12.4 GHz in which total shielding effectiveness (SE) dominated by absorption losses. The total SE is -25 and -61 dB of CF and CF-Ni, it is governed by absorption losses -48.5 dB in CF-Ni. This increase is due to the increase in dielectric and magnetic losses of ferromagnetic Ni nanoparticles with high surface area. Thus, light weight CF embedded with small amount of magnetic nanoparticles can be useful material for stealth technology.

  14. Co-production of hydrogen and carbon nanotubes on nickel foam via methane catalytic decomposition

    NASA Astrophysics Data System (ADS)

    Ping, Dan; Wang, Chaoxian; Dong, Xinfa; Dong, Yingchao

    2016-04-01

    The co-production of COx-free hydrogen and carbon nanotubes (CNTs) was achieved on 3-dimensional (3D) macroporous nickel foam (NF) via methane catalytic decomposition (MCD) over nano-Ni catalysts using chemical vapor deposition (CVD) technique. By a simple coating of a NiO-Al2O3 binary mixture sol followed by a drying-calcination-reduction treatment, NF supported composite catalysts (denoted as NiyAlOx/NF) with Al2O3 transition-layer incorporated with well-dispersed nano-Ni catalysts were successfully prepared. The effects of Ni loading, calcination temperature and reaction temperature on the performance for simultaneous production of COx-free hydrogen and CNTs were investigated in detail. Catalysts before and after MCD were characterized by XRD, TPR, SEM, TEM, TG and Raman spectroscopy technology. Results show that increasing Ni loading, lowering calcination temperature and optimizing MCD reaction temperature resulted in high production efficiency of COx-free H2 and carbon, but broader diameter distribution of CNTs. Through detailed parameter optimization, the catalyst with a Ni/Al molar ratio of 0.1, calcination temperature of 550 °C and MCD temperature of 650 °C was favorable to simultaneously produce COx-free hydrogen with a growth rate as high as 10.3% and CNTs with uniform size on NF.

  15. One-dimensional NiCo2O4 nanowire arrays grown on nickel foam for high-performance lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhou, Xiangyang; Chen, Guanghui; Tang, Jingjing; Ren, Yongpeng; Yang, Juan

    2015-12-01

    With the ever-increasing power and energy needs in application of advanced consumer electronics and related technologies, developing electrode materials with both high energy and power densities holds the key for satisfying the urgent demand of energy storage worldwide. Herein, we report the successful preparation of NiCo2O4 nanowire arrays that are grown on nickel foam via a simple hydrothermal method followed by an annealing process. The electron microscopy images of the obtained NiCo2O4 nanowires reveal that the NiCo2O4 nanowires are uniformly distributed and anchored on the surface of nickel foam. Benefited from the unique structure of NiCo2O4 nanowires on a nickel foam substrate, the as prepared materials exhibit a high reversible capacity of 1048.8 mAh g-1 at 100 mA g-1 and show excellent rate performance for lithium storage.

  16. A V2O5/conductive-polymer core/shell nanobelt array on three-dimensional graphite foam: a high-rate, ultrastable, and freestanding cathode for lithium-ion batteries.

    PubMed

    Chao, Dongliang; Xia, Xinhui; Liu, Jilei; Fan, Zhanxi; Ng, Chin Fan; Lin, Jianyi; Zhang, Hua; Shen, Ze Xiang; Fan, Hong Jin

    2014-09-01

    A thin polymer shell helps V2O5 a lot. Short V2O5 nanobelts are grown directly on 3D graphite foam as a lithium-ion battery (LIB) cathode material. A further coating of a poly(3,4-ethylenedioxythiophene) (PEDOT) thin shell is the key to the high performance. An excellent high-rate capability and ultrastable cycling up to 1000 cycles are demonstrated. PMID:24888872

  17. Three-dimensional marginal separation

    NASA Technical Reports Server (NTRS)

    Duck, Peter W.

    1988-01-01

    The three dimensional marginal separation of a boundary layer along a line of symmetry is considered. The key equation governing the displacement function is derived, and found to be a nonlinear integral equation in two space variables. This is solved iteratively using a pseudo-spectral approach, based partly in double Fourier space, and partly in physical space. Qualitatively, the results are similar to previously reported two dimensional results (which are also computed to test the accuracy of the numerical scheme); however quantitatively the three dimensional results are much different.

  18. Three-dimensional silicon micromachining

    NASA Astrophysics Data System (ADS)

    Azimi, S.; Song, J.; Dang, Z. Y.; Liang, H. D.; Breese, M. B. H.

    2012-11-01

    A process for fabricating arbitrary-shaped, two- and three-dimensional silicon and porous silicon components has been developed, based on high-energy ion irradiation, such as 250 keV to 1 MeV protons and helium. Irradiation alters the hole current flow during subsequent electrochemical anodization, allowing the anodization rate to be slowed or stopped for low/high fluences. For moderate fluences the anodization rate is selectively stopped only at depths corresponding to the high defect density at the end of ion range, allowing true three-dimensional silicon machining. The use of this process in fields including optics, photonics, holography and nanoscale depth machining is reviewed.

  19. Three dimensional colorimetric assay assemblies

    SciTech Connect

    Charych, D.; Reichart, A.

    2000-06-27

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  20. Creating Three-Dimensional Scenes

    ERIC Educational Resources Information Center

    Krumpe, Norm

    2005-01-01

    Persistence of Vision Raytracer (POV-Ray), a free computer program for creating photo-realistic, three-dimensional scenes and a link for Mathematica users interested in generating POV-Ray files from within Mathematica, is discussed. POV-Ray has great potential in secondary mathematics classrooms and helps in strengthening students' visualization…

  1. Three-dimensional stellarator codes

    PubMed Central

    Garabedian, P. R.

    2002-01-01

    Three-dimensional computer codes have been used to develop quasisymmetric stellarators with modular coils that are promising candidates for a magnetic fusion reactor. The mathematics of plasma confinement raises serious questions about the numerical calculations. Convergence studies have been performed to assess the best configurations. Comparisons with recent data from large stellarator experiments serve to validate the theory. PMID:12140367

  2. Three dimensional colorimetric assay assemblies

    DOEpatents

    Charych, Deborah; Reichart, Anke

    2000-01-01

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flu virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  3. Three-Dimensional Lissajous Figures.

    ERIC Educational Resources Information Center

    D'Mura, John M.

    1989-01-01

    Described is a mechanically driven device for generating three-dimensional harmonic space figures with different frequencies and phase angles on the X, Y, and Z axes. Discussed are apparatus, viewing stereo pairs, equations of motion, and using space figures in classroom. (YP)

  4. Experiments, modeling and simulation of the magnetic behavior of inhomogeneously coated nickel/aluminum hybrid foams

    NASA Astrophysics Data System (ADS)

    Jung, A.; Klis, D.; Goldschmidt, F.

    2015-03-01

    Open-cell metal foams are used as lightweight construction elements, energy absorbers or as support for catalytic coatings. Coating of open-cell metal foams is not only used for catalytic applications, but it leads also to tremendous increase in stiffness and energy absorption capacity. A non-line of sight coating technique for complex 3D structures is electrodeposition. Unfortunately, due to the 3D porosity and the related problems in mass transport limitation during the deposition, it is not possible to produce homogeneously coated foams. In the present contribution, we present a semi-non-destructive technique applicable to determine the coating thickness distribution of magnetic coatings by measuring the remanent magnetic field of coated foams. In order to have a closer look at the mass transport mechanism, a numerical model was developed to predict the field scans for different coating thickness distributions in the foams. For long deposition times the deposition reaches a steady state whereas a Helmholtz equation is sufficient to predict the coating thickness distribution. The applied current density could be identified as the main influencing parameter. Based on the developed model, it is possible to improve the electrodeposition process and hence the homogeneity in the coating thickness of coated metal foams. This leads to enhanced mechanical properties of the hybrid foams and contributes to better and resource-efficient energy absorbers and lightweight materials.

  5. Influence of the rate of filtration of a complexly alloyed nickel melt through a foam-ceramic filter on the sulfur impurity content in the metal

    NASA Astrophysics Data System (ADS)

    Sidorov, V. V.; Min, P. G.; Folomeikin, Yu. I.; Vadeev, V. E.

    2015-06-01

    The article discusses the possibility of additional refining of a complexly alloyed nickel melt from a sulfur impurity by decreasing the filtration rate during the passage of the melt through a foam-ceramic filter. The degree of sulfur removal from the melt is shown to depend on its content in the alloy and the melt filtration rate.

  6. Preparation of Mesoporous Silica Templated Metal Nanowire Films on Foamed Nickel Substrates

    SciTech Connect

    Campbell, Roger; Kenik, Edward A; Bakker, Martin; Havrilla, George; Montoya, Velma; Shamsuzzoha, Mohammed

    2006-01-01

    A method has been developed for the formation of high surface area nanowire films on planar and three-dimensional metal electrodes. These nanowire films are formed via electrodeposition into a mesoporous silica film. The mesoporous silica films are formed by a sol-gel process using Pluronic tri-block copolymers to template mesopore formation on both planar and three-dimensional metal electrodes. Surface area increases of up to 120-fold have been observed in electrodes containing a templated film when compared to the same types of electrodes without the templated film.

  7. Facile template-free synthesis of vertically aligned polypyrrole nanosheets on nickel foams for flexible all-solid-state asymmetric supercapacitors

    NASA Astrophysics Data System (ADS)

    Yang, Xiangwen; Lin, Zhixing; Zheng, Jingxu; Huang, Yingjuan; Chen, Bin; Mai, Yiyong; Feng, Xinliang

    2016-04-01

    This paper reports a novel and remarkably facile approach towards vertically aligned nanosheets on three-dimensional (3D) Ni foams. Conducting polypyrrole (PPy) sheets were grown on Ni foam through the volatilization of the environmentally friendly solvent from an ethanol-water solution of pyrrole (Py), followed by the polymerization of the coated Py in ammonium persulfate (APS) solution. The PPy-decorated Ni foams and commercial activated carbon (AC) modified Ni foams were employed as the two electrodes for the assembly of flexible all-solid-state asymmetric supercapacitors. The sheet-like structure of PPy and the macroporous feature of the Ni foam, which render large electrode-electrolyte interfaces, resulted in good capacitive performance of the supercapacitors. Moreover, a high energy density of ca. 14 Wh kg-1 and a high power density of 6.2 kW kg-1 were achieved for the all-solid-state asymmetric supercapacitors due to the wide cell voltage window.This paper reports a novel and remarkably facile approach towards vertically aligned nanosheets on three-dimensional (3D) Ni foams. Conducting polypyrrole (PPy) sheets were grown on Ni foam through the volatilization of the environmentally friendly solvent from an ethanol-water solution of pyrrole (Py), followed by the polymerization of the coated Py in ammonium persulfate (APS) solution. The PPy-decorated Ni foams and commercial activated carbon (AC) modified Ni foams were employed as the two electrodes for the assembly of flexible all-solid-state asymmetric supercapacitors. The sheet-like structure of PPy and the macroporous feature of the Ni foam, which render large electrode-electrolyte interfaces, resulted in good capacitive performance of the supercapacitors. Moreover, a high energy density of ca. 14 Wh kg-1 and a high power density of 6.2 kW kg-1 were achieved for the all-solid-state asymmetric supercapacitors due to the wide cell voltage window. Electronic supplementary information (ESI) available: ESI

  8. Three-dimensional fault drawing

    SciTech Connect

    Dongan, L. )

    1992-01-01

    In this paper, the author presents a structure interpretation based on three-dimensional fault drawing. It is required that fault closure must be based on geological theory, spacial plotting principle and restrictions in seismic exploration. Geological structure can be well ascertained by analysing the shapes and interrelation of the faults which have been drawn through reasonable fault point closure and fault point correlation. According to this method, the interrelation of fault points is determined by first closing corresponding fault points in intersecting sections, then reasonably correlating the relevant fault points. Fault point correlation is not achieved in base map, so its correctness can be improved greatly. Three-dimensional fault closure is achieved by iteratively revising. The closure grid should be densified gradually. The distribution of major fault system is determined prior to secondary faults. Fault interpretation by workstation also follows this procedure.

  9. Three-dimensional obstetric ultrasound.

    PubMed

    Tache, Veronique; Tarsa, Maryam; Romine, Lorene; Pretorius, Dolores H

    2008-04-01

    Three-dimensional ultrasound has gained a significant popularity in obstetrical practice in recent years. The advantage of this modality in some cases is in question, however. This article provides a basic review of volume acquisition, mechanical positioning, and display modalities. Multiple uses of this technique in obstetrical care including first trimester applications and its utility in clarification of fetal anatomy such as brain, face, heart, and skeleton is discussed. PMID:18450140

  10. Three-dimensional coronary angiography

    NASA Astrophysics Data System (ADS)

    Suurmond, Rolf; Wink, Onno; Chen, James; Carroll, John

    2005-04-01

    Three-Dimensional Coronary Angiography (3D-CA) is a novel tool that allows clinicians to view and analyze coronary arteries in three-dimensional format. This will help to find accurate length estimates and to find the optimal viewing angles of a lesion based on the three-dimensional vessel orientation. Various advanced algorithms are incorporated in this 3D processing utility including 3D-RA calibration, ECG phase selection, 2D vessel extraction, and 3D vessel modeling into a utility with optimized workflow and ease-of-use features, which is fully integrated in the environment of the x-ray catheterization lab. After the 3D processing, the 3D vessels can be viewed and manipulated interactively inside the operating room. The TrueView map provides a quick overview of gantry angles with optimal visualization of a single or bifurcation lesion. Vessel length measurements can be performed without risk of underestimating a vessel segment due to foreshortening. Vessel cross sectional diameters can also be measured. Unlike traditional, projection-based quantitative coronary analysis, the additional process of catheter calibration is not needed for diameter measurements. Validation studies show a high reproducibility of the measurements, with little user dependency.

  11. Hierarchical NiO Nanoflake Arrays on Nickel Foam as a Supercapacitor Electrode with High Capacitance and High Rate Capability.

    PubMed

    Yang, Guangwu; He, Bing; Guo, Wenyue; Zhao, Lianming; Xue, Qingzhong; Li, Hulin

    2016-04-01

    In this paper, we report a simple and cost-effective method for fabricating hierarchical NiO nanoflake arrays on nickel foam. X-ray diffraction, scanning electron microscope and transmission electron microscope are employed to study the morphology and structure of the as-synthesized NiO materials. Galvanostatic charge/discharge measurements demonstrate that the hierarchical NiO nanocomposite displays excellent capacitive behavior between the potential range of -0.1-0.5 V, and a maximum specific capacitance as high as 823 F g-1 can be achieved at a charge/discharge current density of 4 A g-1, and it only decreases by 20% when the current density increases to 12 A g-1. The remarkable electrochemical performance of this hierarchical NiO nanocomposite indicates the areat application potential in supercapacitors. PMID:27451782

  12. Vanadium nanobelts coated nickel foam 3D bifunctional electrode with excellent catalytic activity and stability for water electrolysis.

    PubMed

    Yu, Yu; Li, Pei; Wang, Xiaofang; Gao, Wenyu; Shen, Zongxu; Zhu, Yanan; Yang, Shuliang; Song, Weiguo; Ding, Kejian

    2016-05-19

    Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm(-2) for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm(-2) with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity. PMID:27152646

  13. Vanadium nanobelts coated nickel foam 3D bifunctional electrode with excellent catalytic activity and stability for water electrolysis

    NASA Astrophysics Data System (ADS)

    Yu, Yu; Li, Pei; Wang, Xiaofang; Gao, Wenyu; Shen, Zongxu; Zhu, Yanan; Yang, Shuliang; Song, Weiguo; Ding, Kejian

    2016-05-01

    Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm-2 for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm-2 with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity.Pursuit of highly active, stable and low-cost electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key point for large-scale water splitting. A vanadium nanobelts coating on a nickel foam (V/NF) is proposed as an excellent 3D bifunctional electrode for water electrolysis here, which exhibits high activities with overpotentials of 292 and 176 mV at 10 mA cm-2 for OER and HER, respectively. When employed as a bifunctional electrocatalyst in an alkaline water electrolyzer, a cell voltage of 1.80 V was required to achieve 20 mA cm-2 with a slight increase during a 24 h durability test. The existence of the appropriate amount of nitrogen and oxygen elements in the surface region of vanadium nanobelts is regarded to be responsible for the electrocatalytic activity. Electronic supplementary information (ESI) available: More SEM, TEM images, XRD patterns, LSV curves, XPS spectra. See DOI: 10.1039/c6nr02395a

  14. Nickel sulfide microsphere film on Ni foam as an efficient bifunctional electrocatalyst for overall water splitting.

    PubMed

    Zhu, Wenxin; Yue, Xiaoyue; Zhang, Wentao; Yu, Shaoxuan; Zhang, Yuhuan; Wang, Jing; Wang, Jianlong

    2016-01-25

    Developing low-cost, efficient, and bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is an appealing yet challenging task. Herein, for the first time, a NiS microsphere film was grown in situ on Ni foam (NiS/Ni foam) via a sulfurization reaction as an efficient bifunctional electrocatalyst for overall water splitting with superior activity and good durability. This NiS/Ni foam electrode delivers 20 mA cm(-2) at an overpotential of 158 mV for the HER and 50 mA cm(-2) at an overpotential of 335 mV for the OER in 1.0 M KOH. This bifunctional electrode also enables a high-efficiency alkaline water electrolyzer with 10 mA cm(-2) at a cell voltage of only 1.64 V, which could be promising in water splitting devices for large-scale hydrogen production. PMID:26661579

  15. Three-dimensional Camera Phone

    NASA Astrophysics Data System (ADS)

    Iizuka, Keigo

    2004-12-01

    An inexpensive technique for realizing a three-dimensional (3D) camera phone display is presented. Light from the liquid-crystal screen of a camera phone is linearly polarized, and its direction of polarization is easily manipulated by a cellophane sheet used as a half-waveplate. The novel 3D camera phone display is made possible solely by optical components without resorting to computation, so that the 3D image is displayed in real time. Quality of the original image is not sacrificed in the process of converting it into a 3D image.

  16. Solvothermal synthesis of NiAl double hydroxide microspheres on a nickel foam-graphene as an electrode material for pseudo-capacitors

    SciTech Connect

    Momodu, Damilola; Bello, Abdulhakeem; Dangbegnon, Julien; Barzeger, Farshad; Taghizadeh, Fatimeh; Fabiane, Mopeli; Manyala, Ncholu; Johnson, A. T. Charlie

    2014-09-15

    In this paper, we demonstrate excellent pseudo-capacitance behavior of nickel-aluminum double hydroxide microspheres (NiAl DHM) synthesized by a facile solvothermal technique using tertbutanol as a structure-directing agent on nickel foam-graphene (NF-G) current collector as compared to use of nickel foam current collector alone. The structure and surface morphology were studied by X-ray diffraction analysis, Raman spectroscopy and scanning and transmission electron microscopies respectively. NF-G current collector was fabricated by chemical vapor deposition followed by an ex situ coating method of NiAl DHM active material which forms a composite electrode. The pseudocapacitive performance of the composite electrode was investigated by cyclic voltammetry, constant charge–discharge and electrochemical impedance spectroscopy measurements. The composite electrode with the NF-G current collector exhibits an enhanced electrochemical performance due to the presence of the conductive graphene layer on the nickel foam and gives a specific capacitance of 1252 F g{sup −1} at a current density of 1 A g{sup −1} and a capacitive retention of about 97% after 1000 charge–discharge cycles. This shows that these composites are promising electrode materials for energy storage devices.

  17. Preparations of TiO2 film coated on foam nickel substrate by sol-gel processes and its photocatalytic activity for degradation of acetaldehyde.

    PubMed

    Hu, Hai; Xiao, Wen-jun; Yuan, Jian; Shi, Jian-wei; Chen, Ming-xia; Shang Guan, Wen-feng

    2007-01-01

    Anatase TiO2 films were successfully prepared on foam nickel substrates by sol-gel technique using tetrabutyl titanate as precursor. The characteristics of the TiO2 films were investigated by XPS, XRD, FE-SEM, TEM and UV-Vis absorption spectra. The photocatalytic activities of TiO2 films were investigated by photocatalytic degradation reactions of gaseous acetaldehyde, an indoor pollutant, under ultraviolet light irradiation. It was found that Ni2+ doping into Ti02 films due to the foam nickel substrates resulted in the extension of absorption edges of TiO2 films from UV region to visible light region. The pre-heating for foam nickel substrates resulted in the formation of NiO layer, which prevented effectively the injection of photogenerated electrons from TiO2 films to metal nickel. The TiO2 films displayed high photocatalytic activity for the degradation of acetaldehyde, and were enhanced by calcining the substrates and coating TiO2 films repeatedly. The high activity was mainly attributed to the improvement of the characteristics of substrate surface and the increase of active sites on photocatalyst. PMID:17913158

  18. Facile template-free synthesis of vertically aligned polypyrrole nanosheets on nickel foams for flexible all-solid-state asymmetric supercapacitors.

    PubMed

    Yang, Xiangwen; Lin, Zhixing; Zheng, Jingxu; Huang, Yingjuan; Chen, Bin; Mai, Yiyong; Feng, Xinliang

    2016-04-28

    This paper reports a novel and remarkably facile approach towards vertically aligned nanosheets on three-dimensional (3D) Ni foams. Conducting polypyrrole (PPy) sheets were grown on Ni foam through the volatilization of the environmentally friendly solvent from an ethanol-water solution of pyrrole (Py), followed by the polymerization of the coated Py in ammonium persulfate (APS) solution. The PPy-decorated Ni foams and commercial activated carbon (AC) modified Ni foams were employed as the two electrodes for the assembly of flexible all-solid-state asymmetric supercapacitors. The sheet-like structure of PPy and the macroporous feature of the Ni foam, which render large electrode-electrolyte interfaces, resulted in good capacitive performance of the supercapacitors. Moreover, a high energy density of ca. 14 Wh kg(-1) and a high power density of 6.2 kW kg(-1) were achieved for the all-solid-state asymmetric supercapacitors due to the wide cell voltage window. PMID:27050711

  19. Three-dimensional visual stimulator

    NASA Astrophysics Data System (ADS)

    Takeda, Tsunehiro; Fukui, Yukio; Hashimoto, Keizo; Hiruma, Nobuyuki

    1995-02-01

    We describe a newly developed three-dimensional visual stimulator (TVS) that can change independently the directions, distances, sizes, luminance, and varieties of two sets of targets for both eyes. It consists of liquid crystal projectors (LCP's) that generate the flexible images of targets, Badal otometers that change target distances without changing the visual angles, and relay-lens systems that change target directions. A special control program is developed for real-time control of six motors and two LCP's in the TVS together with a three-dimensional optometer III that simultaneously measures eye movement, accommodation, pupil diameter, and head movement. distance, 0 to -20 D; direction, 16 horizontally and 15 vertically; size, 0-2 deg visual angle; and luminance, 10-2-10 2 cd/m2. The target images are refreshed at 60 Hz and speeds with which the target makes a smooth change (ramp stimuli) are size, 10 deg/s. A simple application demonstrates the performance.

  20. Ultralight, Strong, Three-Dimensional SiC Structures.

    PubMed

    Chabi, Sakineh; Rocha, Victoria G; García-Tuñón, Esther; Ferraro, Claudio; Saiz, Eduardo; Xia, Yongde; Zhu, Yanqiu

    2016-02-23

    Ultralight and strong three-dimensional (3D) silicon carbide (SiC) structures have been generated by the carbothermal reduction of SiO with a graphene foam (GF). The resulting SiC foams have an average height of 2 mm and density ranging between 9 and 17 mg cm(-3). They are the lightest reported SiC structures. They consist of hollow struts made from ultrathin SiC flakes and long 1D SiC nanowires growing from the trusses, edges, and defect sites between layers. AFM results revealed an average flake thickness of 2-3 nm and lateral size of 2 μm. In-situ compression tests in the scanning electron microscope (SEM) show that, compared with most of the existing lightweight foams, the present 3D SiC exhibited superior compression strengths and significant recovery after compression strains of about 70%. PMID:26580985

  1. Three Dimensional P-doped Graphene Synthesized by Eco-Friendly Chemical Vapor Deposition for Oxygen Reduction Reactions.

    PubMed

    Li, Xiaoguang; Qiu, Yunfeng; Hu, Ping An

    2016-06-01

    Heteroatom doping provides possibilities for changing the electronic properties of graphene. Three Dimensional P-doped graphene (3DPG) was fabricated via chemical vapor deposition (CVD) using nickel foam as template and triphenylphosphine (TPP) as C and P sources simultaneously without using toxic organic solvent as carrier liquid. The invasion of P atoms into graphene networks make them non-electroneutral and consequently favor the adsorption of oxygen and O-O bond cleavage due to the charge polarization increase of the P-C bond. Thus, the as-prepared 3DPG served as an efficient electrocatalyst for oxygen reduction reaction (ORR). Additionally, the 3D porous structure is favorable for the mass transfer of electrolytes ions, hence 3DPG exhibit better electrocatalytic activity, long-term stability, and tolerance to crossover effect of methanol than pristine 3D graphene and Pt/C for ORR. PMID:27427693

  2. Processing and Characterization of Nickel-Manganese-Gallium Shape-Memory Fibers and Foams

    NASA Astrophysics Data System (ADS)

    Zheng, Peiqi-Paige

    Ferromagnetic Ni-Mn-Ga shape memory alloys with large magnetic field-induced strains are promising candidates for actuators. Magnetic shape memory alloys display magnetic-field-induced strain (MFIS) of up to 10%, as single crystals. Polycrystalline materials are much easier to create but display a near-zero MFIS because twinning of neighboring grains introduces strain incompatibility leading to high internal stresses. Pores reduce these incompatibilities between grains and thus increase the MFIS of polycrystalline Ni-Mn-Ga which after training (thermo-magneto-mechanical cycling) exhibits MFIS as high as 8.7%. In this thesis, a systematic study of the effect of porosity on the magneto-mechanical properties of polycrystalline Ni-Mn-Ga foams is presented. The MFIS increased with increasing porosity, demonstrating that removal of constraints by addition of porosity is responsible for the high MFIS in polycrystalline foams. Ni-Mn-Ga foams with 57 volume percent of 355-500 micrometers open pores, with and without directional solidification were cast replicated. One directional solidified foam specimen showed a maximum magnetic-field induced strain of 0.65%, which is twice the value displayed by other foam specimens without directional solidification. This improvement is consistent with a reduction of incompatibility stresses under magnetic field from the reduced crystallographic misorientation between neighboring grains. Polycrystalline Ni-Mn-Ga foam displays ˜1% MFIS after the hermo-magnetic training. To show this effect in this highly textured sample, neutron diffraction texture measurements were conducted with a magnetic field applied at various orientations to the sample, demonstrating that selection of martensite variants takes place during cooling. Oligocrystalline Ni-Mn-Ga foams with an open porosity of 63.5?0.7% were created by a sintering replication process using NaCl space-holders. The high surface/volume ratio and mechanical stability under cyclic strain

  3. Three-dimensional coil inductor

    DOEpatents

    Bernhardt, Anthony F.; Malba, Vincent

    2002-01-01

    A three-dimensional coil inductor is disclosed. The inductor includes a substrate; a set of lower electrically conductive traces positioned on the substrate; a core placed over the lower traces; a set of side electrically conductive traces laid on the core and the lower traces; and a set of upper electrically conductive traces attached to the side traces so as to form the inductor. Fabrication of the inductor includes the steps of forming a set of lower traces on a substrate; positioning a core over the lower traces; forming a set of side traces on the core; connecting the side traces to the lower traces; forming a set of upper traces on the core; and connecting the upper traces to the side traces so as to form a coil structure.

  4. In situ growth of ruthenium oxide-nickel oxide nanorod arrays on nickel foam as a binder-free integrated cathode for hydrogen evolution

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Xiong, Kun; Chen, Siguo; Li, Li; Deng, Zihua; Wei, Zidong

    2015-01-01

    In this paper we describe a novel catalyst based on RuO2-NiO nanorod arrays constructed in situ on a Ni foam substrate by a hydrothermal process for catalyzing the hydrogen evolution reaction (HER). Field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), linear scanning voltammetry (LSV), and electrochemical impedance spectroscopy (EIS) are used to systematically investigate the microstructure, composition, and electrochemical performance of the catalyst. The prepared electrode exhibits excellent HER performance and long-term stability. This impressive electrochemical performance is largely attributed to the material's unique nanostructure. Noticeable the presence of nickel oxide/hydroxide on the surface of the catalyst promotes the dissociation of water and the formation of hydrogen intermediates that can then adsorb onto the nearby ruthenium species and recombine into molecular hydrogen at a very rapid rate. The hydrothermal method for directly growing electroactive nanostructured arrays on a conductive substrate offers a promising route for developing a new class of Ni-based high performance electrodes for the HER in practical applications.

  5. Fast Response Shape Memory Effect Titanium Nickel (TiNi) Foam Torque Tubes

    NASA Technical Reports Server (NTRS)

    Jardine, Peter

    2014-01-01

    Shape Change Technologies has developed a process to manufacture net-shaped TiNi foam torque tubes that demonstrate the shape memory effect. The torque tubes dramatically reduce response time by a factor of 10. This Phase II project matured the actuator technology by rigorously characterizing the process to optimize the quality of the TiNi and developing a set of metrics to provide ISO 9002 quality assurance. A laboratory virtual instrument engineering workbench (LabVIEW'TM')-based, real-time control of the torsional actuators was developed. These actuators were developed with The Boeing Company for aerospace applications.

  6. Three dimensional magnetic abacus memory

    NASA Astrophysics Data System (ADS)

    Zhang, Shilei; Zhang, Jingyan; Baker, Alexander A.; Wang, Shouguo; Yu, Guanghua; Hesjedal, Thorsten

    2014-08-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme. It is inspired by the idea of second quantisation, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered `quantised' Hall voltage, each representing a count of the spin-up and spin-down layers in the stack. This new memory system further allows for both flexible scaling of the system and fast communication among cells. The magnetic abacus provides a promising approach for future nonvolatile 3D magnetic random access memory.

  7. Three dimensional magnetic abacus memory

    NASA Astrophysics Data System (ADS)

    Zhang, Shilei; Zhang, Jingyan; Baker, Alexander; Wang, Shouguo; Yu, Guanghua; Hesjedal, Thorsten

    2015-03-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the individual data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme which envisages a classical abacus with the beads operated by electron spins. It is inspired by the idea of second quantization, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered `quantized' Hall voltage, representing a count of the spin-up and spin-down layers in the stack. This concept of `second quantization of memory' realizes the 3D memory architecture with superior reading and operation efficiency, thus is a promising approach for future nonvolatile magnetic random access memory.

  8. Three dimensional magnetic abacus memory.

    PubMed

    Zhang, ShiLei; Zhang, JingYan; Baker, Alexander A; Wang, ShouGuo; Yu, GuangHua; Hesjedal, Thorsten

    2014-01-01

    Stacking nonvolatile memory cells into a three-dimensional matrix represents a powerful solution for the future of magnetic memory. However, it is technologically challenging to access the data in the storage medium if large numbers of bits are stacked on top of each other. Here we introduce a new type of multilevel, nonvolatile magnetic memory concept, the magnetic abacus. Instead of storing information in individual magnetic layers, thereby having to read out each magnetic layer separately, the magnetic abacus adopts a new encoding scheme. It is inspired by the idea of second quantisation, dealing with the memory state of the entire stack simultaneously. Direct read operations are implemented by measuring the artificially engineered 'quantised' Hall voltage, each representing a count of the spin-up and spin-down layers in the stack. This new memory system further allows for both flexible scaling of the system and fast communication among cells. The magnetic abacus provides a promising approach for future nonvolatile 3D magnetic random access memory. PMID:25146338

  9. Dynamic Three-Dimensional Echocardiography

    NASA Astrophysics Data System (ADS)

    Matsusaka, Katsuhiko; Doi, Motonori; Oshiro, Osamu; Chihara, Kunihiro

    2000-08-01

    Conventional three-dimensional (3D) ultrasound imaging equipment for diagnosis requires much time to reconstruct 3D images or fix the view point for observing the 3D image. Thus, it is inconvenient for cardiac diagnosis. In this paper, we propose a new dynamic 3D echocardiography system. The system produces 3D images in real-time and permits changes in view point. This system consists of ultrasound diagnostic equipment, a digitizer and a computer. B-mode images are projected to a virtual 3D space by referring to the position of the probe of the ultrasound diagnosis equipment. The position is obtained by the digitizer to which the ultrasound probe is attached. The 3D cardiac image is constructed from B-mode images obtained simultaneously in the cardiac cycle. To obtain the same moment of heartbeat in the cardiac cycle, this system uses the electrocardiography derived from the diagnosis equipment. The 3D images, which show various scenes of the stage of heartbeat action, are displayed sequentially. The doctor can observe 3D images cut in any plane by pushing a button of the digitizer and zooming with the keyboard. We evaluated our prototype system by observation of a mitral valve in motion.

  10. Three-dimensional display technologies

    PubMed Central

    Geng, Jason

    2014-01-01

    The physical world around us is three-dimensional (3D), yet traditional display devices can show only two-dimensional (2D) flat images that lack depth (i.e., the third dimension) information. This fundamental restriction greatly limits our ability to perceive and to understand the complexity of real-world objects. Nearly 50% of the capability of the human brain is devoted to processing visual information [Human Anatomy & Physiology (Pearson, 2012)]. Flat images and 2D displays do not harness the brain’s power effectively. With rapid advances in the electronics, optics, laser, and photonics fields, true 3D display technologies are making their way into the marketplace. 3D movies, 3D TV, 3D mobile devices, and 3D games have increasingly demanded true 3D display with no eyeglasses (autostereoscopic). Therefore, it would be very beneficial to readers of this journal to have a systematic review of state-of-the-art 3D display technologies. PMID:25530827

  11. Three-dimensional laser microvision.

    PubMed

    Shimotahira, H; Iizuka, K; Chu, S C; Wah, C; Costen, F; Yoshikuni, Y

    2001-04-10

    A three-dimensional (3-D) optical imaging system offering high resolution in all three dimensions, requiring minimum manipulation and capable of real-time operation, is presented. The system derives its capabilities from use of the superstructure grating laser source in the implementation of a laser step frequency radar for depth information acquisition. A synthetic aperture radar technique was also used to further enhance its lateral resolution as well as extend the depth of focus. High-speed operation was made possible by a dual computer system consisting of a host and a remote microcomputer supported by a dual-channel Small Computer System Interface parallel data transfer system. The system is capable of operating near real time. The 3-D display of a tunneling diode, a microwave integrated circuit, and a see-through image taken by the system operating near real time are included. The depth resolution is 40 mum; lateral resolution with a synthetic aperture approach is a fraction of a micrometer and that without it is approximately 10 mum. PMID:18357177

  12. Three-Dimensional Schlieren Measurements

    NASA Astrophysics Data System (ADS)

    Sutherland, Bruce; Cochrane, Andrea

    2004-11-01

    Schlieren systems visualise disturbances that change the index of refraction of a fluid, for example due to temperature or salinity disturbances. `Synthetic schlieren' refers to a recent advance in which these disturbances are visualised with a digital camera and image-processing technology rather than the classical use of parabolic mirrors and a knife-edge. In a typical setup, light from an image of horizontal lines or dots passes almost horizontally through the test section of a fluid to a CCD camera. Refractive index disturbances distort the image and digital comparison of successive images reveals the plan-form structure and time evolution of the disturbances. If the disturbance is effectively two-dimensional, meaning that it is uniform across the line-of-sight of the camera, then its magnitude as well as its structure can measured through simple inversion of an algebraic equation. If the structure is axisymmetric with rotation-axis perpendicular to the line of sight, the magnitude of the disturbance can be measured through inversion of a non-singular square matrix. Here we report upon the extension of this work toward measuring the magnitude of a fully three-dimensional disturbance. This is done by analysing images from two perspectives through the test section and using inversion tomography techniques to reconstruct the disturbance field. The results are tested against theoretical predictions and experimental measurements.

  13. True three-dimensional camera

    NASA Astrophysics Data System (ADS)

    Kornreich, Philipp; Farell, Bart

    2013-01-01

    An imager that can measure the distance from each pixel to the point on the object that is in focus at the pixel is described. This is accomplished by short photo-conducting lightguides at each pixel. In the eye the rods and cones are the fiber-like lightguides. The device uses ambient light that is only coherent in spherical shell-shaped light packets of thickness of one coherence length. Modern semiconductor technology permits the construction of lightguides shorter than a coherence length of ambient light. Each of the frequency components of the broad band light arriving at a pixel has a phase proportional to the distance from an object point to its image pixel. Light frequency components in the packet arriving at a pixel through a convex lens add constructively only if the light comes from the object point in focus at this pixel. The light in packets from all other object points cancels. Thus the pixel receives light from one object point only. The lightguide has contacts along its length. The lightguide charge carriers are generated by the light patterns. These light patterns, and thus the photocurrent, shift in response to the phase of the input signal. Thus, the photocurrent is a function of the distance from the pixel to its object point. Applications include autonomous vehicle navigation and robotic vision. Another application is a crude teleportation system consisting of a camera and a three-dimensional printer at a remote location.

  14. Palladium deposits spontaneously grown on nickel foam for electro-catalyzing methanol oxidation: Effect of precursors

    NASA Astrophysics Data System (ADS)

    Niu, Xiangheng; Zhao, Hongli; Lan, Minbo

    2016-02-01

    Methanol, a high-energy substance, is widely used for green fuel cells. However, the sluggish electrochemical methanol oxidation reaction (MOR) on state-of-the-art catalysts still requires for exploring high-performance and low-cost materials to further promote the reaction kinetics at low overpotentials. Here we carried out the first electrocatalytic comparison study of two Ni foam-supported Pd nanomaterials (Pd-2-Ni and Pd-4-Ni, respectively), obtained through the spontaneous galvanic replacement of Ni with different palladic precursors ([PdCl4]2- and [PdCl6]2-, respectively), toward MOR. With replacement, Pd deposits with discrepant arrangements and coverages were grown on the porous Ni support. Compared to commercial Pd/C, both Pd-2-Ni and Pd-4-Ni exhibited better mass activity and catalytic durability for MOR in alkaline media. More interestingly, different palladic precursors made a significant effect on the catalytic performance of the Ni foam-supported Pd deposits. In Pd-4-Ni, the 2:1 stoichiometric replacement of Ni with [PdCl6]2- enabled the incompact arrangement of Pd structures, with more exposure of Ni atoms adjoined to Pd atoms on the catalytic interface compared to Pd-2-Ni. As a result, with the favorable Ni-neighbor-Pd regime and the higher utilization efficiency of Pd atoms, the synthesized Pd-4-Ni catalyst provided a mass activity of approximately 1.5 times higher than Pd-2-Ni toward MOR.

  15. Porous Iron Cobaltate Nanoneedles Array on Nickel Foam as Anode Materials for Lithium-Ion Batteries with Enhanced Electrochemical Performance.

    PubMed

    Liu, Li; Zhang, Huijuan; Mu, Yanping; Yang, Jiao; Wang, Yu

    2016-01-20

    A monocrystalline and porous FeCo2O4 nanoneedles array growing directly on a nickel foam substrate was obtained by a hydrothermal technique accompanying with combustion of the one-dimensional precursor. The average length of the FeCo2O4 nanoneedles is approximately 2 μm, while the diameter of the root segment of the nanoneedle can be estimated to be around 100 nm, which gradually reduces to only several nanometers at the top. When the as-prepared porous FeCo2O4 nanoneedles array with a high surface area of 58.49 m(2) g(-1) was applied as binder-free electrode in lithium-ion batteries, it exhibited satisfactory electrochemical performance, such as outstanding reversibility (Coulombic efficiency of approximately 92-95%), high specific capacity (1962 mAh g(-1) at the current density of 100 mA g(-1)), and excellent rate performance (discharge capacity of 875 mAh g(-1) at the current density of 2000 mA g(-1)), due to the various favorable conditions. Undoubtedly, the simple but effective strategy can be expanded to other high-performance binary metal-oxide materials. PMID:26713359

  16. FeS/nickel foam as stable and efficient counter electrode material for quantum dot sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Geng, Huifang; Zhu, Liqun; Li, Weiping; Liu, Huicong; Quan, Linlin; Xi, Fanxing; Su, Xunwen

    2015-05-01

    A stable and efficient FeS/nickel foam (NF) counter electrode for quantum dots-sensitized solar cells (QDSCs) is first fabricated by electrochemistry deposition and characterized with scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), current voltage and impedance spectroscopy. The QDSC based on FeS/NF CE achieves a power conversion efficiency (PCE) of 4.39% attributing to the high fill factor (FF) of 0.58, and the PCE is much higher than that of based on FeS/FTO CE (2.76%) and other reported FeS CEs (1.76% and 3.34%). The phenomenon that the electrode can transform between FeS/NF (in the polysulfide electrolyte) and Fe2O3/NF (in the air) spontaneously is first reported. And the excellent stability in photoelectric performance of the CE is also demonstrated in the present work. Therefore, the FeS/NF is very promising as a stable and efficient CE for QDSCs.

  17. Effect of composites based nickel foam anode in microbial fuel cell using Acetobacter aceti and Gluconobacter roseus as a biocatalysts.

    PubMed

    Karthikeyan, Rengasamy; Krishnaraj, Navanietha; Selvam, Ammaiyappan; Wong, Jonathan Woon-Chung; Lee, Patrick K H; Leung, Michael K H; Berchmans, Sheela

    2016-10-01

    This study explores the use of materials such as chitosan (chit), polyaniline (PANI) and titanium carbide (TC) as anode materials for microbial fuel cells. Nickel foam (NF) was used as the base anode substrate. Four different types of anodes (NF, NF/PANI, NF/PANI/TC, NF/PANI/TC/Chit) are thus prepared and used in batch type microbial fuel cells operated with a mixed consortium of Acetobacter aceti and Gluconobacter roseus as the biocatalysts and bad wine as a feedstock. A maximum power density of 18.8Wm(-3) (≈2.3 times higher than NF) was obtained in the case of the anode modified with a composite of PANI/TC/Chit. The MFCs running under a constant external resistance of (50Ω) yielded 14.7% coulombic efficiency with a maximum chemical oxygen demand (COD) removal of 87-93%. The overall results suggest that the catalytic materials embedded in the chitosan matrix show the best performance and have potentials for further development. PMID:26970695

  18. Metallized polymeric foam material

    NASA Technical Reports Server (NTRS)

    Birnbaum, B. A.; Bilow, N.

    1974-01-01

    Open-celled polyurethane foams can be coated uniformly with thin film of metal by vapor deposition of aluminum or by sensitization of foam followed by electroless deposition of nickel or copper. Foam can be further processed to increase thickness of metal overcoat to impart rigidity or to provide inert surface with only modest increase in weight.

  19. Three-dimensional boundary layers approaching separation

    NASA Technical Reports Server (NTRS)

    Williams, J. C., III

    1976-01-01

    The theory of semi-similar solutions of the laminar boundary layer equations is applied to several flows in which the boundary layer approaches a three-dimensional separation line. The solutions obtained are used to deduce the nature of three-dimensional separation. It is shown that in these cases separation is of the "ordinary" type. A solution is also presented for a case in which a vortex is embedded within the three-dimensional boundary layer.

  20. Complete dechlorination of 2,4-dichlorophenol in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel composite electrode.

    PubMed

    Sun, Zhirong; Wei, Xuefeng; Han, Yanbo; Tong, Shan; Hu, Xiang

    2013-01-15

    The electrochemically reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel electrode (Pd/PPy-CTAB/foam-Ni electrode) was investigated in this paper. Pd/PPy-CTAB/foam-Ni electrode was prepared and characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) adsorption and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The influences of some experimental factors such as the dechlorination current, dechlorination time and the initial pH on the removal efficiency and the current efficiency of 2,4-DCP dechlorination on Pd/PPy-CTAB/foam-Ni electrode were studied. Complete removal of 2,4-DCP was achieved and the current efficiency of 47.4% could be obtained under the conditions of the initial pH of 2.2, the dechlorination current of 5 mA and the dechlorination time of 50 min when the initial 2,4-DCP concentration was 100 mg L(-1). The analysis of high performance liquid chromatography (HPLC) identified that the intermediate products were 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP). The final products were mainly phenol. Its further reduction product cyclohexanone was also detected. The electrocatalytic dechlorination pathways of 2,4-DCP on Pd/PPy-CTAB/foam-Ni electrode were discussed. The stability of the electrode was favorable that it could keep dechlorination efficiency at 100% after having been reused 10 times. Results revealed that the stable prepared Pd/PPy-CTAB/foam-Ni electrode presented a good application prospect in dechlorination process with high effectiveness and low cost. PMID:23270952

  1. Removal of copper and iron by polyurethane foam column in FIA system for the determination of nickel in pierced ring.

    PubMed

    Vongboot, Monnapat; Suesoonthon, Monrudee

    2015-01-01

    Polyurethane foam (PUF) mini-column was used to eliminate copper and iron for the determination of nickel in pierced rings. The PUF mini-column was connected to FIA system for on-line sorption of copper and iron in complexes form of CuSCN(+) and FeSCN(2+). For this season, the acid solution containing a mixture of Ni(II), Fe(III), Cu(II) and SCN(-) ions was firstly flew into the PUF column. Then, the percolated solution which Fe(III) and Cu(II) ions is separated from analysis was injected into FIA system to react with 4-(2-pyridylazo) resorcinol (PAR) reagent in basic condition which this method is called pH gradient technique. The Ni-PAR complexes obtained were measured theirs absorbance at 500 nm by UV visible spectrophotometer. In this study, it was found that Cu(II) and Fe(III) were completely to form complexes with 400 mmol/L KSCN and entirely to eliminate in acidic condition at pH 3.0. In the optimum condition of these experiments, the method provided the linear relationship between absorbance and the concentration of Ni(II) in the range from 5.00 to 30.00 mg/L. Linear equation is y=0.0134x+0.0033 (R(2)=0.9948). Precision, assessed in the term of the relative standard deviation, RSD, and accuracy for multiple determinations obtained in values of 0.77-1.73% and 97.4%, respectively. The level of an average amount of Ni(II) in six piercing rings was evaluated to be 14.78 mg/g. PMID:25281109

  2. Three-dimensional jamming and flows of soft glassy materials.

    PubMed

    Ovarlez, G; Barral, Q; Coussot, P

    2010-02-01

    Various disordered dense systems, such as foams, gels, emulsions and colloidal suspensions, undergo a jamming transition from a liquid state (they flow) to a solid state below a yield stress. Their structure, which has been thoroughly studied with powerful means of three-dimensional characterization, shows some analogy with that of glasses, which led to them being named soft glassy materials. However, despite its importance for geophysical and industrial applications, their rheological behaviour, and its microscopic origin, is still poorly known, in particular because of its nonlinear nature. Here we show from two original experiments that a simple three-dimensional continuum description of the behaviour of soft glassy materials can be built. We first show that when a flow is imposed in some direction there is no yield resistance to a secondary flow: these systems are always unjammed simultaneously in all directions of space. The three-dimensional jamming criterion seems to be the plasticity criterion encountered in most solids. We also find that they behave as simple liquids in the direction orthogonal to that of the main flow; their viscosity is inversely proportional to the main flow shear rate, as a signature of shear-induced structural relaxation, in close similarity to the structural relaxations driven by temperature and density in other glassy systems. PMID:20062046

  3. Three-dimensional imaging through scattering media using three-dimensionally coded pattern projection.

    PubMed

    Ando, Takamasa; Horisaki, Ryoichi; Tanida, Jun

    2015-08-20

    We propose a method for visualizing three-dimensional objects in scattering media. Our method is based on active illumination using three-dimensionally coded patterns and a numerical algorithm employing a sparsity constraint. We experimentally demonstrated the proposed imaging method for test charts located three-dimensionally at different depths in the space behind a translucent sheet. PMID:26368767

  4. Three Dimensional Illustrating--Three-Dimensional Vision and Deception of Sensibility

    ERIC Educational Resources Information Center

    Szállassy, Noémi; Gánóczy, Anita; Kriska, György

    2009-01-01

    The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena…

  5. Three Dimensional Mapping of Nicle Oxidation States Using Full Field Xray Absorption Near Edge Structure Nanotomography

    SciTech Connect

    Nelson, G.J.; Chu, Y.; Harris, W.M.; Izzo, J.R.; Grew, K.N., Chiu, W.K.S.; Yi, J.; Andrews, J.C.; Liu, Y., Pierro, P.

    2011-04-28

    The reduction-oxidation cycling of the nickel-based oxides in composite solid oxide fuel cells and battery electrodes is directly related to cell performance. A greater understanding of nickel redox mechanisms at the microstructural level can be achieved in part using transmission x-ray microscopy (TXM) to explore material oxidation states. X-ray nanotomography combined with x-ray absorption near edge structure (XANES) spectroscopy has been applied to study samples containing distinct regions of nickel and nickel oxide (NiO) compositions. Digitally processed images obtained using TXM demonstrate the three-dimensional chemical mapping and microstructural distribution capabilities of full-field XANES nanotomography.

  6. Nickel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The agricultural significance of nickel (Ni) is becoming increasingly apparent; yet, relative few farmers, growers, specialists or researchers know much about its function in crops, nor symptoms of deficiency or toxicity. The body of knowledge is reviewed regarding Ni’s background, uptake, transloc...

  7. Three-Dimensional, Nondestructive Imaging of Low Density Materials

    SciTech Connect

    Kinney, J.H.; Haupt, D.L.; Lemay, J.D.

    1999-10-29

    The goal of this study was to develop a three-dimensional imaging method for studies of deformation in low-density materials during loading, and to implement finite element solutions of the elastic equations based on the images. Specimens of silica-reinforced polysiloxane foam pads, 15 mm in diameter by 1 mm thick, were used for this study. The nominal pore density was 50%, and the pores approximated interconnected spheres. The specimens were imaged with microtomography at {approx}16{micro}m resolution. A rotating stage with micrometer driven compression allowed imaging of the foams during deformation with precise registration of the images. A finite element mesh, generated from the image voxels, was used to calculate the mechanical properties of the structure, and the results were compared with conventional mechanical testing. The foam exhibited significant nonlinear behavior with compressive loading. The finite-element calculations from the images, which were in excellent agreement with experimental data, suggested that nonlinear behavior in the load displacement curves arises from buckling of the cell walls during compression and not from any nonlinear properties of the base elastomer. High-resolution microtomography, coupled with efficient finite-element modeling, shows promise for improving our understanding of the deformation behavior of cellular materials.

  8. Three dimensional optic tissue culture and process

    NASA Technical Reports Server (NTRS)

    Spaulding, Glenn F. (Inventor); Prewett, Tacey L. (Inventor); Goodwin, Thomas J. (Inventor); Francis, Karen M. (Inventor); Cardwell, Delmar R. (Inventor); Oconnor, Kim (Inventor); Fitzgerald, Wendy S. (Inventor); Aten, Laurie A. (Inventor)

    1994-01-01

    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioreactor at low shear conditions. The tissue forms normal, functional tissue organization and extracellular matrix.

  9. Three Dimensional Optic Tissue Culture and Process

    NASA Technical Reports Server (NTRS)

    OConnor, Kim C. (Inventor); Spaulding, Glenn F. (Inventor); Goodwin, Thomas J. (Inventor); Aten, Laurie A. (Inventor); Francis, Karen M. (Inventor); Caldwell, Delmar R. (Inventor); Prewett, Tacey L. (Inventor); Fitzgerald, Wendy S. (Inventor)

    1999-01-01

    A process for artificially producing three-dimensional optic tissue has been developed. The optic cells are cultured in a bioireactor at low shear conditions. The tissue forms as normal, functional tissue grows with tissue organization and extracellular matrix formation.

  10. Three-dimensional stellarator equilibria by iteration

    SciTech Connect

    Boozer, A.H.

    1983-02-01

    The iterative method of evaluating plasma equilibria is especially simple in a magnetic coordinate representation. This method is particularly useful for clarifying the subtle constraints of three-dimensional equilibria and studying magnetic surface breakup at high plasma beta.

  11. THREE-DIMENSIONAL MODEL FOR HYPERTHERMIA CALCULATIONS

    EPA Science Inventory

    Realistic three-dimensional models that predict temperature distributions with a high degree of spatial resolution in bodies exposed to electromagnetic (EM) fields are required in the application of hyperthermia for cancer treatment. To ascertain the thermophysiologic response of...

  12. Device fabrication: Three-dimensional printed electronics

    NASA Astrophysics Data System (ADS)

    Lewis, Jennifer A.; Ahn, Bok Y.

    2015-02-01

    Can three-dimensional printing enable the mass customization of electronic devices? A study that exploits this method to create light-emitting diodes based on 'quantum dots' provides a step towards this goal.

  13. Three-Dimensional Icosahedral Phase Field Quasicrystal

    NASA Astrophysics Data System (ADS)

    Subramanian, P.; Archer, A. J.; Knobloch, E.; Rucklidge, A. M.

    2016-08-01

    We investigate the formation and stability of icosahedral quasicrystalline structures using a dynamic phase field crystal model. Nonlinear interactions between density waves at two length scales stabilize three-dimensional quasicrystals. We determine the phase diagram and parameter values required for the quasicrystal to be the global minimum free energy state. We demonstrate that traits that promote the formation of two-dimensional quasicrystals are extant in three dimensions, and highlight the characteristics required for three-dimensional soft matter quasicrystal formation.

  14. Three dimensional responsive structure of tough hydrogels

    NASA Astrophysics Data System (ADS)

    Yang, Xuxu; Ma, Chunxin; Li, Chi; Xie, Yuhan; Huang, Xiaoqiang; Jin, Yongbin; Zhu, Ziqi; Liu, Junjie; Li, Tiefeng

    2015-04-01

    Three dimensional responsive structures have high value for the application of responsive hydrogels in various fields such as micro fluid control, tissue engineering and micro robot. Whereas various hydrogels with stimuli-responsive behaviors have been developed, designing and fabricating of the three dimensional responsive structures remain challenging. We develop a temperature responsive double network hydrogel with novel fabrication methods to assemble the complex three dimensional responsive structures. The shape changing behavior of the structures can be significantly increased by building blocks with various responsiveness. Mechanical instability is built into the structure with the proper design and enhance the performance of the structure. Finite element simulation are conducted to guide the design and investigate the responsive behavior of the hydrogel structures

  15. Vision in our three-dimensional world

    PubMed Central

    2016-01-01

    Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269595

  16. Vision in our three-dimensional world.

    PubMed

    Parker, Andrew J

    2016-06-19

    Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices.This article is part of the themed issue 'Vision in our three-dimensional world'. PMID:27269595

  17. Three-dimensional microbubble streaming flows

    NASA Astrophysics Data System (ADS)

    Rallabandi, Bhargav; Marin, Alvaro; Rossi, Massimiliano; Kaehler, Christian; Hilgenfeldt, Sascha

    2014-11-01

    Streaming due to acoustically excited bubbles has been used successfully for applications such as size-sorting, trapping and focusing of particles, as well as fluid mixing. Many of these applications involve the precise control of particle trajectories, typically achieved using cylindrical bubbles, which establish planar flows. Using astigmatic particle tracking velocimetry (APTV), we show that, while this two-dimensional picture is a useful description of the flow over short times, a systematic three-dimensional flow structure is evident over long time scales. We demonstrate that this long-time three-dimensional fluid motion can be understood through asymptotic theory, superimposing secondary axial flows (induced by boundary conditions at the device walls) onto the two-dimensional description. This leads to a general framework that describes three-dimensional flows in confined microstreaming systems, guiding the design of applications that profit from minimizing or maximizing these effects.

  18. Topology of three-dimensional separated flows

    NASA Technical Reports Server (NTRS)

    Tobak, M.; Peake, D. J.

    1981-01-01

    Based on the hypothesis that patterns of skin-friction lines and external streamlines reflect the properties of continuous vector fields, topology rules define a small number of singular points (nodes, saddle points, and foci) that characterize the patterns on the surface and on particular projections of the flow (e.g., the crossflow plane). The restricted number of singular points and the rules that they obey are considered as an organizing principle whose finite number of elements can be combined in various ways to connect together the properties common to all steady three dimensional viscous flows. Introduction of a distinction between local and global properties of the flow resolves an ambiguity in the proper definition of a three dimensional separated flow. Adoption of the notions of topological structure, structural stability, and bifurcation provides a framework to describe how three dimensional separated flows originate and succeed each other as the relevant parameters of the problem are varied.

  19. Three-dimensional separation and reattachment

    NASA Technical Reports Server (NTRS)

    Peake, D. J.; Tobak, M.

    1982-01-01

    The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be constrained as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.

  20. Three-dimensional separation and reattachment

    NASA Technical Reports Server (NTRS)

    Peake, D. J.; Tobak, M.

    1982-01-01

    The separation of three dimensional turbulent boundary layers from the lee of flight vehicles at high angles of attack is investigated. The separation results in dominant, large scale, coiled vortex motions that pass along the body in the general direction of the free stream. In all cases of three dimensional flow separation and reattachment, the assumption of continuous vector fields of skin friction lines and external flow streamlines, coupled with simple laws of topology, provides a flow grammar whose elemental constituents are the singular points: the nodes, spiral nodes (foci), and saddles. The phenomenon of three dimensional separation may be construed as either a local or a global event, depending on whether the skin friction line that becomes a line of separation originates at a node or a saddle point.

  1. Three-Dimensional Robotic Vision System

    NASA Technical Reports Server (NTRS)

    Nguyen, Thinh V.

    1989-01-01

    Stereoscopy and motion provide clues to outlines of objects. Digital image-processing system acts as "intelligent" automatic machine-vision system by processing views from stereoscopic television cameras into three-dimensional coordinates of moving object in view. Epipolar-line technique used to find corresponding points in stereoscopic views. Robotic vision system analyzes views from two television cameras to detect rigid three-dimensional objects and reconstruct numerically in terms of coordinates of corner points. Stereoscopy and effects of motion on two images complement each other in providing image-analyzing subsystem with clues to natures and locations of principal features.

  2. Three-dimensional magnetic bubble memory system

    NASA Technical Reports Server (NTRS)

    Stadler, Henry L. (Inventor); Katti, Romney R. (Inventor); Wu, Jiin-Chuan (Inventor)

    1994-01-01

    A compact memory uses magnetic bubble technology for providing data storage. A three-dimensional arrangement, in the form of stacks of magnetic bubble layers, is used to achieve high volumetric storage density. Output tracks are used within each layer to allow data to be accessed uniquely and unambiguously. Storage can be achieved using either current access or field access magnetic bubble technology. Optical sensing via the Faraday effect is used to detect data. Optical sensing facilitates the accessing of data from within the three-dimensional package and lends itself to parallel operation for supporting high data rates and vector and parallel processing.

  3. Three-Dimensional Extended Bargmann Supergravity.

    PubMed

    Bergshoeff, Eric; Rosseel, Jan

    2016-06-24

    We show that three-dimensional general relativity, augmented with two vector fields, allows for a nonrelativistic limit, different from the standard limit leading to Newtonian gravity, that results in a well-defined action which is of the Chern-Simons type. We show that this three-dimensional "extended Bargmann gravity," after coupling to matter, leads to equations of motion allowing a wider class of background geometries than the ones that one encounters in Newtonian gravity. We give the supersymmetric generalization of these results and point out an important application in the context of calculating partition functions of nonrelativistic field theories using localization techniques. PMID:27391712

  4. Three-Dimensional Extended Bargmann Supergravity

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric; Rosseel, Jan

    2016-06-01

    We show that three-dimensional general relativity, augmented with two vector fields, allows for a nonrelativistic limit, different from the standard limit leading to Newtonian gravity, that results in a well-defined action which is of the Chern-Simons type. We show that this three-dimensional "extended Bargmann gravity," after coupling to matter, leads to equations of motion allowing a wider class of background geometries than the ones that one encounters in Newtonian gravity. We give the supersymmetric generalization of these results and point out an important application in the context of calculating partition functions of nonrelativistic field theories using localization techniques.

  5. Materials for foam type insulation

    NASA Technical Reports Server (NTRS)

    Hill, W. E.

    1971-01-01

    An internal foam fabrication is one of the concepts being considered for cryogenic insulation on the hydrogen tanks of the shuttle vehicle. The three-dimensional polyurethane used on the S-4 B tanks failed to meet the higher temperature requirements of the shuttle vehicle, however, and other foams under consideration include polyisocyanurates, polyphenylene oxides, polyimides, and polybenzimidazoles. Improved adhesive systems for attaching the foams to the interior tank wall are under study.

  6. Three-Dimensional Visualization of Particle Tracks.

    ERIC Educational Resources Information Center

    Julian, Glenn M.

    1993-01-01

    Suggests ways to bring home to the introductory physics student some of the excitement of recent discoveries in particle physics. Describes particle detectors and encourages the use of the Standard Model along with real images of particle tracks to determine three-dimensional views of tracks. (MVL)

  7. Three-Dimensional Messages for Interstellar Communication

    NASA Astrophysics Data System (ADS)

    Vakoch, Douglas A.

    One of the challenges facing independently evolved civilizations separated by interstellar distances is to communicate information unique to one civilization. One commonly proposed solution is to begin with two-dimensional pictorial representations of mathematical concepts and physical objects, in the hope that this will provide a foundation for overcoming linguistic barriers. However, significant aspects of such representations are highly conventional, and may not be readily intelligible to a civilization with different conventions. The process of teaching conventions of representation may be facilitated by the use of three-dimensional representations redundantly encoded in multiple formats (e.g., as both vectors and as rasters). After having illustrated specific conventions for representing mathematical objects in a three-dimensional space, this method can be used to describe a physical environment shared by transmitter and receiver: a three-dimensional space defined by the transmitter--receiver axis, and containing stars within that space. This method can be extended to show three-dimensional representations varying over time. Having clarified conventions for representing objects potentially familiar to both sender and receiver, novel objects can subsequently be depicted. This is illustrated through sequences showing interactions between human beings, which provide information about human behavior and personality. Extensions of this method may allow the communication of such culture-specific features as aesthetic judgments and religious beliefs. Limitations of this approach will be noted, with specific reference to ETI who are not primarily visual.

  8. Three-dimensional rf structure calculations

    SciTech Connect

    Cooper, R.K.; Browman, M.J.; Weiland, T.

    1988-01-01

    The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described. 13 refs., 14 figs.

  9. Three-dimensional RF structure calculations

    NASA Astrophysics Data System (ADS)

    Cooper, R. K.; Browman, M. J.; Weiland, T.

    1989-04-01

    The calculation of three-dimensional rf structures is rapidly approaching adolescence, after having been in its infancy for the last four years. This paper will show the kinds of calculations that are currently being performed in the frequency domain and is a companion paper to one in which time-domain calculations are described.

  10. Growing Three-Dimensional Cocultures Of Cells

    NASA Technical Reports Server (NTRS)

    Wolf, David A.; Goodwin, Thomas J.

    1995-01-01

    Laboratory process provides environmental conditions favoring simultaneous growth of cocultures of mammalian cells of more than one type. Cultures become three-dimensional tissuelike assemblies serving as organoid models of differentiation of cells. Process used, for example, to study growth of human colon cancers, starting from mixtures of normal colonic fibroblasts and partially differentiated colon adenocarcinoma cells.

  11. Three-dimensional colorimetric assay assemblies

    DOEpatents

    Charych, Deborah; Reichert, Anke

    2001-01-01

    A direct assay is described using novel three-dimensional polymeric assemblies which change from a blue to red color when exposed to an analyte, in one case a flue virus. The assemblies are typically in the form of liposomes which can be maintained in a suspension, and show great intensity in their color changes. Their method of production is also described.

  12. Cohomology of real three-dimensional triquadrics

    NASA Astrophysics Data System (ADS)

    Krasnov, Vyacheslav A.

    2012-02-01

    We consider non-singular intersections of three real five-dimensional quadrics. They are referred to for brevity as real three-dimensional triquadrics. We calculate the dimensions of the cohomology spaces of triquadrics with coefficients in the field of two elements.

  13. Three-Dimensional Printing Surgical Applications

    PubMed Central

    Griffin, Michelle F.; Butler, Peter E.

    2015-01-01

    Introduction: Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. Objective: To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Methods: Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Discussion: Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Conclusion: Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice. PMID:26301002

  14. Three-Dimensional Pointers for Stereoscopic Projection.

    ERIC Educational Resources Information Center

    Hayman, H. J. G.

    1984-01-01

    Because class size often limits student opportunity to handle individual models, teachers use stereoscopic projections to demonstrate structural features. Describes three-dimensional pointers for use with different projection systems so teachers can indicate a particular atom or bond to entire classes, avoiding the perspective problems inherent in…

  15. Foam Micromechanics

    SciTech Connect

    Kraynik, A.M.; Neilsen, M.K.; Reinelt, D.A.; Warren, W.E.

    1998-11-03

    Foam evokes many different images: waves breaking at the seashore, the head on a pint of Guinness, an elegant dessert, shaving, the comfortable cushion on which you may be seated... From the mundane to the high tech, foams, emulsions, and cellular solids encompass a broad range of materials and applications. Soap suds, mayonnaise, and foamed polymers provide practical motivation and only hint at the variety of materials at issue. Typical of mukiphase materiaIs, the rheoIogy or mechanical behavior of foams is more complicated than that of the constituent phases alone, which may be gas, liquid, or solid. For example, a soap froth exhibits a static shear modulus-a hallmark of an elastic solid-even though it is composed primarily of two Newtonian fluids (water and air), which have no shear modulus. This apparent paradox is easily resolved. Soap froth contains a small amount of surfactant that stabilizes the delicate network of thin liq- uid films against rupture. The soap-film network deforms in response to a macroscopic strain; this increases interracial area and the corresponding sur- face energy, and provides the strain energy of classical elasticity theory [1]. This physical mechanism is easily imagined but very challenging to quantify for a realistic three-dimensional soap froth in view of its complex geome- try. Foam micromechanics addresses the connection between constituent properties, cell-level structure, and macroscopic mechanical behavior. This article is a survey of micromechanics applied to gas-liquid foams, liquid-liquid emulsions, and cellular solids. We will focus on static response where the foam deformation is very slow and rate-dependent phenomena such as viscous flow can be neglected. This includes nonlinear elasticity when deformations are large but reversible. We will also discuss elastic- plastic behavior, which involves yield phenomena. Foam structures based on polyhedra packed to fill space provide a unify- ing geometrical theme. Because a two

  16. Three-dimensional thermal modeling of electric vehicle batteries

    NASA Astrophysics Data System (ADS)

    Lee, J.; Choi, K. W.; Yao, N. P.; Christianson, C. C.

    1985-10-01

    A generic three-dimensional thermal model was developed for analyzing the thermal behavior of electric-vehicle batteries. The model calculates temperature distribution and excursion of a battery during discharge, change, and open circuit. The model takes into account the effects of heat generation, internal conduction and convection, and external heat dissipation on the temperature distribution in a battery. The three-dimensional feature of the model permits incorporation of various asymmetric boundary conditions; thus the effects of cell orientation and packaging on thermal behavior can be analyzed for a multiple-cell battery pack. Various modes of boundary heat transfer such as radiation, insulation, and natural and forced convections were also included in the model. Model predictions agreed well with the temperature distributions measured in nickel/iron batteries. Application of the thermal model to a closely packed 330-Ah module of five cells indicated that excessive temperature rise will occur upon discharge. Forced air convection is not effective for cooling the module.

  17. Effect of silver or copper middle layer on the performance of palladium modified nickel foam electrodes in the 2-chlorobiphenyl dechlorination.

    PubMed

    He, Zhiqiao; Sun, Junjun; Wei, Jie; Wang, Qiong; Huang, Chengxiang; Chen, Jianmeng; Song, Shuang

    2013-04-15

    To enhance the activity of chemi-deposited palladium/nickel foam (Pd/Ni) electrodes used for an electrochemical dechlorination process, silver or copper was deposited electrochemically onto the nickel foam substrate (to give Ag/Ni or Cu/Ni) before the chemical deposition of palladium. The physicochemical properties of the resulting materials (Pd/Ni, Pd/Ag/Ni and Pd/Cu/Ni) were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and their electrochemical catalytic activities were evaluated by monitoring the electrochemical dechlorination of 2-chlorobiphenyl (2-CB) in strongly alkaline methanol/water solution. The results show that the Pd/Ag/Ni and Pd/Cu/Ni electrodes had consistently higher electrocatalytic activities and current efficiencies (CEs) compared with the untreated Pd/Ni electrode. The Pd/Ag/Ni electrode exhibited the highest activity. The dechlorination was also studied as a function of Pd loading, the Ag or Cu interlayer loadings, and the current density. The Pd loading and the interlayer loadings both had positive effects on the dechlorination reaction. Increasing the current density increased the reaction rate but reduced the CE. The improvement of the electrocatalytic activities of the Pd/Ni electrode by applying the interlayer of Ag or Cu resulted from the enlargement of the effective surface area of the electrode and the adjustment of the metal-H bond energy to the appropriate value, as well as the effective adsorption of 2-CB on Ag. Moreover, the high catalytic activity of the Pd/Ag/Ni electrode was maintained after six successive cyclic experiments, whereas Pd/Cu/Ni electrodes deactivate severely under the same conditions. PMID:23454456

  18. Electrodeposition of hierarchically structured three-dimensional nickel–iron electrodes for efficient oxygen evolution at high current densities

    PubMed Central

    Lu, Xunyu; Zhao, Chuan

    2015-01-01

    Large-scale industrial application of electrolytic splitting of water has called for the development of oxygen evolution electrodes that are inexpensive, robust and can deliver large current density (>500 mA cm−2) at low applied potentials. Here we show that an efficient oxygen electrode can be developed by electrodepositing amorphous mesoporous nickel–iron composite nanosheets directly onto macroporous nickel foam substrates. The as-prepared oxygen electrode exhibits high catalytic activity towards water oxidation in alkaline solutions, which only requires an overpotential of 200 mV to initiate the reaction, and is capable of delivering current densities of 500 and 1,000 mA cm−2 at overpotentials of 240 and 270 mV, respectively. The electrode also shows prolonged stability against bulk water electrolysis at large current. Collectively, the as-prepared three-dimensional structured electrode is the most efficient oxygen evolution electrode in alkaline electrolytes reported to the best of our knowledge, and can potentially be applied for industrial scale water electrolysis. PMID:25776015

  19. Binary cooperative NiCo2O4 on the nickel foams with quasi-two-dimensional precursors: a bridge between 'supercapacitor' and 'battery' in electrochemical energy storage.

    PubMed

    Peng, Tao; Qian, Zhongyu; Wang, Jun; Qu, Liangti; Wang, Peng

    2015-02-28

    Some inorganic quasi-two-dimensional nanomaterials such as cobalt-nickel hydroxides are kinetically facile for a capacitive charge storage process. However, high performance capacitive charge storage needs a balance of the ionic and electronic transporting, and to build up an integrated architecture on substrates step by step and utilize the interface better is still a key challenge. As the interfacial assembly has conflicted with our goals for high-performance capacitive charge storage process, we identify theoretically and experimentally binary cooperative nanoscale interfacial materials to solve the problem. Co-Ni-hydroxide precursors were prepared by hybrid quasi-two-dimensional nanosheets and hetero-oriented nanocrystallines walls. Followed by dip-dry and annealing, NiCo2O4 could adhere to the nickel foams robustly with a solution-based surface treatment. Moreover, an unusual phenomenon in the electrochemical test inspired us to establish a bridge between 'supercapacitor' and 'battery'. The bridged gap highlights a new design idea for high-performance energy storage. PMID:25624031

  20. Real time three dimensional sensing system

    DOEpatents

    Gordon, Steven J.

    1996-01-01

    The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane.

  1. Real time three dimensional sensing system

    DOEpatents

    Gordon, S.J.

    1996-12-31

    The invention is a three dimensional sensing system which utilizes two flexibly located cameras for receiving and recording visual information with respect to a sensed object illuminated by a series of light planes. Each pixel of each image is converted to a digital word and the words are grouped into stripes, each stripe comprising contiguous pixels. One pixel of each stripe in one image is selected and an epi-polar line of that point is drawn in the other image. The three dimensional coordinate of each selected point is determined by determining the point on said epi-polar line which also lies on a stripe in the second image and which is closest to a known light plane. 7 figs.

  2. Three-dimensional visualization of a qutrit

    NASA Astrophysics Data System (ADS)

    Kurzyński, Paweł; Kołodziejski, Adrian; Laskowski, Wiesław; Markiewicz, Marcin

    2016-06-01

    We present a surprisingly simple three-dimensional Bloch sphere representation of a qutrit, i.e., a single three-level quantum system. We start with a symmetric state of a two-qubit system and relate it to the spin-1 representation. Using this representation we associate each qutrit state with a three-dimensional vector a and a metric tensor Γ ̂ which satisfy a .Γ ̂.a ≤1 . This resembles the well known condition for qubit Bloch vectors in which case Γ ̂=1 . In our case the vector a corresponds to spin-1 polarization, whereas the tensor Γ ̂ is a function of polarization uncertainties. Alternatively, a is a local Bloch vector of a symmetric two-qubit state and Γ ̂ is a function of the corresponding correlation tensor.

  3. Transformation equation in three-dimensional photoelasticity.

    PubMed

    Ainola, Leo; Aben, Hillar

    2006-03-01

    Optical phenomena that occur when polarized light passes through an inhomogeneous birefringent medium are complicated, especially when the principal directions of the dielectric tensor rotate on the light ray. This case is typical in three-dimensional photoelasticity, in particular in integrated photoelasticity by stress analysis on the basis of measured polarization transformations. Analysis of polarization transformations in integrated photoelasticity has been based primarily on a system of two first-order differential equations. Using a transformed coordinate in the direction of light propagation, we have derived a single fourth-order differential equation of three-dimensional photoelasticity. For the case of uniform rotation of the principal directions we have obtained an analytical solution. PMID:16539073

  4. Analysis of three-dimensional transonic compressors

    NASA Technical Reports Server (NTRS)

    Bourgeade, A.

    1984-01-01

    A method for computing the three-dimensional transonic flow around the blades of a compressor or of a propeller is given. The method is based on the use of the velocity potential, on the hypothesis that the flow is inviscid, irrotational and isentropic. The equation of the potential is solved in a transformed space such that the surface of the blade is mapped into a plane where the periodicity is implicit. This equation is in a nonconservative form and is solved with the help of a finite difference method using artificial time. A computer code is provided and some sample results are given in order to demonstrate the influence of three-dimensional effects and the blade's rotation.

  5. Three-Dimensional Images For Robot Vision

    NASA Astrophysics Data System (ADS)

    McFarland, William D.

    1983-12-01

    Robots are attracting increased attention in the industrial productivity crisis. As one significant approach for this nation to maintain technological leadership, the need for robot vision has become critical. The "blind" robot, while occupying an economical niche at present is severely limited and job specific, being only one step up from the numerical controlled machines. To successfully satisfy robot vision requirements a three dimensional representation of a real scene must be provided. Several image acquistion techniques are discussed with more emphasis on the laser radar type instruments. The autonomous vehicle is also discussed as a robot form, and the requirements for these applications are considered. The total computer vision system requirement is reviewed with some discussion of the major techniques in the literature for three dimensional scene analysis.

  6. Three-dimensional bio-printing.

    PubMed

    Gu, Qi; Hao, Jie; Lu, YangJie; Wang, Liu; Wallace, Gordon G; Zhou, Qi

    2015-05-01

    Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at the exploratory stage. This review summarize the development of 3D bio-printing and its potential in medical applications, as well as discussing the current challenges faced by 3D bio-printing. PMID:25921944

  7. Three dimensional fabrication at small size scales

    PubMed Central

    Leong, Timothy G.; Zarafshar, Aasiyeh M.; Gracias, David H.

    2010-01-01

    Despite the fact that we live in a three-dimensional (3D) world and macroscale engineering is 3D, conventional sub-mm scale engineering is inherently two-dimensional (2D). New fabrication and patterning strategies are needed to enable truly three-dimensionally-engineered structures at small size scales. Here, we review strategies that have been developed over the last two decades that seek to enable such millimeter to nanoscale 3D fabrication and patterning. A focus of this review is the strategy of self-assembly, specifically in a biologically inspired, more deterministic form known as self-folding. Self-folding methods can leverage the strengths of lithography to enable the construction of precisely patterned 3D structures and “smart” components. This self-assembling approach is compared with other 3D fabrication paradigms, and its advantages and disadvantages are discussed. PMID:20349446

  8. Simulation of complex three-dimensional flows

    NASA Technical Reports Server (NTRS)

    Diewert, G. S.; Rothmund, H. J.; Nakahashi, K.

    1985-01-01

    The concept of splitting is used extensively to simulate complex three dimensional flows on modern computer architectures. Used in all aspects, from initial grid generation to the determination of the final converged solution, splitting is used to enhance code vectorization, to permit solution driven grid adaption and grid enrichment, to permit the use of concurrent processing, and to enhance data flow through hierarchal memory systems. Three examples are used to illustrate these concepts to complex three dimensional flow fields: (1) interactive flow over a bump; (2) supersonic flow past a blunt based conical afterbody at incidence to a free stream and containing a centered propulsive jet; and (3) supersonic flow past a sharp leading edge delta wing at incidence to the free stream.

  9. Three-dimensional imaging modalities in endodontics

    PubMed Central

    Mao, Teresa

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome. PMID:25279337

  10. Three-dimensional motor schema based navigation

    NASA Technical Reports Server (NTRS)

    Arkin, Ronald C.

    1989-01-01

    Reactive schema-based navigation is possible in space domains by extending the methods developed for ground-based navigation found within the Autonomous Robot Architecture (AuRA). Reformulation of two dimensional motor schemas for three dimensional applications is a straightforward process. The manifold advantages of schema-based control persist, including modular development, amenability to distributed processing, and responsiveness to environmental sensing. Simulation results show the feasibility of this methodology for space docking operations in a cluttered work area.

  11. Generating Three-Dimensional Grids About Anything

    NASA Technical Reports Server (NTRS)

    Sorenson, Reese L.

    1991-01-01

    Three-Dimensional Grids About Anything by Poisson's Equation (3DGRAPE) computer program designed to make computational grids in or about almost any shape. Generated by solution of Poisson's differential equations in three dimensions. Program automatically finds its own values for inhomogeneous terms giving near-orthogonality and controlled grid-cell height at boundaries. Grids generated applied to both viscous and inviscid aerodynamic problems, and to problems in other areas of fluid dynamics. Written in 100 percent FORTRAN 77.

  12. Three-dimensional Lorentz-violating action

    NASA Astrophysics Data System (ADS)

    Nascimento, J. R.; Petrov, A. Yu.; Wotzasek, C.; Zarro, C. A. D.

    2014-03-01

    We demonstrate the generation of the three-dimensional Chern-Simons-like Lorentz-breaking "mixed" quadratic action via an appropriate Lorentz-breaking coupling of vector and scalar fields to the spinor field and study some features of the scalar QED with such a term. We show that the same term emerges through a nonperturbative method, namely the Julia-Toulouse approach of condensation of charges and defects.

  13. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.; York, Jeremy

    2009-06-30

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  14. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.

    2006-09-26

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may e transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  15. Three-dimensional display of document set

    DOEpatents

    Lantrip, David B [Oxnard, CA; Pennock, Kelly A [Richland, WA; Pottier, Marc C [Richland, WA; Schur, Anne [Richland, WA; Thomas, James J [Richland, WA; Wise, James A [Richland, WA

    2001-10-02

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  16. Three-Dimensional Dispaly Of Document Set

    DOEpatents

    Lantrip, David B.; Pennock, Kelly A.; Pottier, Marc C.; Schur, Anne; Thomas, James J.; Wise, James A.

    2003-06-24

    A method for spatializing text content for enhanced visual browsing and analysis. The invention is applied to large text document corpora such as digital libraries, regulations and procedures, archived reports, and the like. The text content from these sources may be transformed to a spatial representation that preserves informational characteristics from the documents. The three-dimensional representation may then be visually browsed and analyzed in ways that avoid language processing and that reduce the analysts' effort.

  17. Three-dimensional simulation of vortex breakdown

    NASA Technical Reports Server (NTRS)

    Kuruvila, G.; Salas, M. D.

    1990-01-01

    The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state.

  18. Three-dimensional adjustment of trilateration data

    NASA Technical Reports Server (NTRS)

    Sung, L.-Y.; Jackson, D. D.

    1985-01-01

    The three-dimensional locations of the monuments in the USGS Hollister trilateration network were adjusted to fit line length observations observed in 1977, using a Bayesian approach, and incorporating prior elevation estimates as data in the adjustment procedure. No significant discrepancies in the measured line lengths were found, but significant elevation adjustments (up to 1.85 m) were needed to fit the length data.

  19. Three-dimensional ballistocardiography in weightlessness

    NASA Technical Reports Server (NTRS)

    Scano, A.

    1981-01-01

    An experiment is described the aim of which is to record a three dimensional ballistocardiogram under the condition of weightlessness and to compare it with tracings recorded on the same subject on the ground as a means of clarifying the meaning of ballistocardiogram waves in different physiological and perphaps pathological conditions. Another purpose is to investigate cardiovascular and possibly fluid adaptations to weightlessness from data collected almost simultaneously on the same subjects during the other cardiovascular during the other cardiovascular and metabolic experiments.

  20. Mineralized three-dimensional bone constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2011-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  1. Mineralized Three-Dimensional Bone Constructs

    NASA Technical Reports Server (NTRS)

    Clarke, Mark S. F. (Inventor); Sundaresan, Alamelu (Inventor); Pellis, Neal R. (Inventor)

    2013-01-01

    The present disclosure provides ex vivo-derived mineralized three-dimensional bone constructs. The bone constructs are obtained by culturing osteoblasts and osteoclast precursors under randomized gravity vector conditions. Preferably, the randomized gravity vector conditions are obtained using a low shear stress rotating bioreactor, such as a High Aspect Ratio Vessel (HARV) culture system. The bone constructs of the disclosure have utility in physiological studies of bone formation and bone function, in drug discovery, and in orthopedics.

  2. The first three-dimensional vanadium hypophosphite.

    PubMed

    Maouel, Hind A; Alonzo, Véronique; Roisnel, Thierry; Rebbah, Houria; Le Fur, Eric

    2009-07-01

    The title synthesized hypophosphite has the formula V(H(2)PO(2))(3). Its structure is based on VO(6) octahedra and (H(2)PO(2))(-) pseudo-tetrahedra. The asymmetric unit contains two crystallographically distinct V atoms and six independent (H(2)PO(2))(-) groups. The connection of the polyhedra generates [VPO(6)H(2)](6-) chains extended along a, b and c, leading to the first three-dimensional network of an anhydrous transition metal hypophosphite. PMID:19578249

  3. Stress tensor correlators in three dimensional gravity

    NASA Astrophysics Data System (ADS)

    Bagchi, Arjun; Grumiller, Daniel; Merbis, Wout

    2016-03-01

    We calculate holographically arbitrary n -point correlators of the boundary stress tensor in three-dimensional Einstein gravity with negative or vanishing cosmological constant. We provide explicit expressions up to 5-point (connected) correlators and show consistency with the Galilean conformal field theory Ward identities and recursion relations of correlators, which we derive. This provides a novel check of flat space holography in three dimensions.

  4. Three-dimensional printing of the retina

    PubMed Central

    Lorber, Barbara; Hsiao, Wen-Kai; Martin, Keith R.

    2016-01-01

    Purpose of review Biological three-dimensional printing has received a lot of media attention over recent years with advances made in printing cellular structures, including skin and heart tissue for transplantation. Although limitations exist in creating functioning organs with this method, the hope has been raised that creating a functional retina to cure blindness is within reach. The present review provides an update on the advances made toward this goal. Recent findings It has recently been shown that two types of retinal cells, retinal ganglion cells and glial cells, can be successfully printed using a piezoelectric inkjet printer. Importantly, the cells remained viable and did not change certain phenotypic features as a result of the printing process. In addition, recent advances in the creation of complex and viable three-dimensional cellular structures have been made. Summary Some first promising steps toward the creation of a functional retina have been taken. It now needs to be investigated whether recent findings can be extended to other cells of the retina, including those derived from human tissue, and if a complex and viable retinal structure can be created through three-dimensional printing. PMID:27045545

  5. Multiparallel Three-Dimensional Optical Microscopy

    NASA Technical Reports Server (NTRS)

    Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel

    2010-01-01

    Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.

  6. Teaching and Assessing Three-Dimensional M

    NASA Astrophysics Data System (ADS)

    Bateman, Robert C., Jr.; Booth, Deborah; Sirochman, Rudy; Richardson, Jane; Richardson, David

    2002-05-01

    Structural concepts such as the exact arrangement of a protein in three dimensions are crucial to almost every aspect of biology and chemistry, yet most of us have not been educated in three-dimensional literacy and all of us need a great deal of help in order to perceive and to communicate structural information successfully. It is in the undergraduate biochemistry course where students learn most concepts of molecular structure pertinent to living systems. We are addressing the issue of three-dimensional structural literacy by having undergraduate students construct kinemages, which are plain text scripts derived from Protein Data Bank coordinate files that can be viewed with the program MAGE. These annotated, interactive, three-dimensional illustrations are designed to develop a molecular story and allow exploration in the world of that story. In the process, students become familiar with the structure-based scientific literature and the Protein Data Bank. Our assessment to date has shown that students perceive kinemage authorship to be more helpful in understanding protein structure than simply viewing prepared kinemages. In addition, students perceived kinemage authorship as being beneficial to their career and a significant motivation to learn biochemistry.

  7. Three-dimensional deformation of orthodontic brackets

    PubMed Central

    Melenka, Garrett W; Nobes, David S; Major, Paul W

    2013-01-01

    Braces are used by orthodontists to correct the misalignment of teeth in the mouth. Archwire rotation is a particular procedure used to correct tooth inclination. Wire rotation can result in deformation to the orthodontic brackets, and an orthodontic torque simulator has been designed to examine this wire–bracket interaction. An optical technique has been employed to measure the deformation due to size and geometric constraints of the orthodontic brackets. Images of orthodontic brackets are collected using a stereo microscope and two charge-coupled device cameras, and deformation of orthodontic brackets is measured using a three-dimensional digital image correlation technique. The three-dimensional deformation of orthodontic brackets will be evaluated. The repeatability of the three-dimensional digital image correlation measurement method was evaluated by performing 30 archwire rotation tests using the same bracket and archwire. Finally, five Damon 3MX and five In-Ovation R self-ligating brackets will be compared using this technique to demonstrate the effect of archwire rotation on bracket design. PMID:23762201

  8. Three-Dimensional Imaging. Chapter 10

    NASA Technical Reports Server (NTRS)

    Kelso, R. M.; Delo, C.

    1999-01-01

    This chapter is concerned with three-dimensional imaging of fluid flows. Although relatively young, this field of research has already yielded an enormous range of techniques. These vary widely in cost and complexity, with the cheapest light sheet systems being within the budgets of most laboratories, and the most expensive Magnetic Resonance Imaging systems available to a select few. Taking the view that the most likely systems to be developed are those using light sheets, the authors will relate their knowledge and experience of such systems. Other systems will be described briefly and references provided. Flows are inherently three-dimensional in structure; even those generated around nominally 2-D surface geometry. It is becoming increasingly apparent to scientists and engineers that the three-dimensionalities, both large and small scale, are important in terms of overall flow structure and species, momentum, and energy transport. Furthermore, we are accustomed to seeing the world in three dimensions, so it is natural that we should wish to view, measure and interpret flows in three-dimensions. Unfortunately, 3-D images do not lend themselves to convenient presentation on the printed page, and this task is one of the challenges facing us.

  9. Three-Dimensional Audio Client Library

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A.

    2005-01-01

    The Three-Dimensional Audio Client Library (3DAudio library) is a group of software routines written to facilitate development of both stand-alone (audio only) and immersive virtual-reality application programs that utilize three-dimensional audio displays. The library is intended to enable the development of three-dimensional audio client application programs by use of a code base common to multiple audio server computers. The 3DAudio library calls vendor-specific audio client libraries and currently supports the AuSIM Gold-Server and Lake Huron audio servers. 3DAudio library routines contain common functions for (1) initiation and termination of a client/audio server session, (2) configuration-file input, (3) positioning functions, (4) coordinate transformations, (5) audio transport functions, (6) rendering functions, (7) debugging functions, and (8) event-list-sequencing functions. The 3DAudio software is written in the C++ programming language and currently operates under the Linux, IRIX, and Windows operating systems.

  10. Three-dimensional stereo by photometric ratios

    SciTech Connect

    Wolff, L.B.; Angelopoulou, E.

    1994-11-01

    We present a methodology for corresponding a dense set of points on an object surface from photometric values for three-dimensional stereo computation of depth. The methodology utilizes multiple stereo pairs of images, with each stereo pair being taken of the identical scene but under different illumination. With just two stereo pairs of images taken under two different illumination conditions, a stereo pair of ratio images can be produced, one for the ratio of left-hand images and one for the ratio of right-hand images. We demonstrate how the photometric ratios composing these images can be used for accurate correspondence of object points. Object points having the same photometric ratio with respect to two different illumination conditions constitute a well-defined equivalence class of physical constraints defined by local surface orientation relative to illumination conditions. We formally show that for diffuse reflection the photometric ratio is invariant to varying camera characteristics, surface albedo, and viewpoint and that therefore the same photometric ratio in both images of a stereo pair implies the same equivalence class of physical constraints. The correspondence of photometric ratios along epipolar lines in a stereo pair of images under different illumination conditions is a correspondence of equivalent physical constraints, and the determination of depth from stereo can be performed. Whereas illumination planning is required, our photometric-based stereo methodology does not require knowledge of illumination conditions in the actual computation of three-dimensional depth and is applicable to perspective views. This technique extends the stereo determination of three-dimensional depth to smooth featureless surfaces without the use of precisely calibrated lighting. We demonstrate experimental depth maps from a dense set of points on smooth objects of known ground-truth shape, determined to within 1% depth accuracy.

  11. Three-dimensional lock and key colloids.

    PubMed

    Wang, Yu; Wang, Yufeng; Zheng, Xiaolong; Yi, Gi-Ra; Sacanna, Stefano; Pine, David J; Weck, Marcus

    2014-05-14

    Colloids with well-defined multicavities are synthesized through the hydrolytic removal of silica cluster templates from organo-silica hybrid patchy particles. The geometry of the cavities stems from the originally assembled cluster templates, displaying well-defined three-dimensional symmetries, ranging from spherical, linear, triangular, tetrahedral, trigonal dipyramidal, octahedral, to pentagonal dipyramidal. The concave surface of the cavities is smooth, and the cavity shallowness and size can be varied. These particles with multicavities can act as "lock" particles with multiple "key holes". Up to n "key" particles can self-assemble into the lock particles via depletion interaction, resulting in multivalent, site-specific, reversible, and flexible bonding. PMID:24785203

  12. Three dimensional digital holographic aperture synthesis.

    PubMed

    Crouch, Stephen; Kaylor, Brant M; Barber, Zeb W; Reibel, Randy R

    2015-09-01

    Aperture synthesis techniques are applied to temporally and spatially diverse digital holograms recorded with a fast focal-plane array. Because the technique fully resolves the downrange dimension using wide-bandwidth FMCW linear-chirp waveforms, extremely high resolution three dimensional (3D) images can be obtained even at very long standoff ranges. This allows excellent 3D image formation even when targets have significant structure or discontinuities, which are typically poorly rendered with multi-baseline synthetic aperture ladar or multi-wavelength holographic aperture ladar approaches. The background for the system is described and system performance is demonstrated through both simulation and experiments. PMID:26368474

  13. High resolution three-dimensional doping profiler

    DOEpatents

    Thundat, Thomas G.; Warmack, Robert J.

    1999-01-01

    A semiconductor doping profiler provides a Schottky contact at one surface and an ohmic contact at the other. While the two contacts are coupled to a power source, thereby establishing an electrical bias in the semiconductor, a localized light source illuminates the semiconductor to induce a photocurrent. The photocurrent changes in accordance with the doping characteristics of the semiconductor in the illuminated region. By changing the voltage of the power source the depth of the depletion layer can be varied to provide a three dimensional view of the local properties of the semiconductor.

  14. Three-dimensional instability of elliptical flow

    NASA Astrophysics Data System (ADS)

    Bayly, B. J.

    1986-10-01

    A clarification of the physical and mathematical nature of Pierrhumbert's (1986) three-dimensional short-wave inviscid instability of simple two-dimensional elliptical flow is presented. The instabilities found are independent of length scale, extending Pierrhumbert's conclusion that the structures of the instabilities are independent of length scale in the limit of large wave number. The fundamental modes are exact solutions of the nonlinear equations, and they are plane waves whose wave vector rotates elliptically around the z axis with a period of 2(pi)/Omega. The growth rates are shown to be the exponents of a matrix Floquet problem, and good agreement is found with previous results.

  15. Three-dimensional ultrasonic colloidal crystals

    NASA Astrophysics Data System (ADS)

    Caleap, Mihai; Drinkwater, Bruce W.

    2016-05-01

    Colloidal assembly represents a powerful method for the fabrication of functional materials. In this article, we describe how acoustic radiation forces can guide the assembly of colloidal particles into structures that serve as microscopic elements in novel acoustic metadevices or act as phononic crystals. Using a simple three-dimensional orthogonal system, we show that a diversity of colloidal structures with orthorhombic symmetry can be assembled with megahertz-frequency (MHz) standing pressure waves. These structures allow rapid tuning of acoustic properties and provide a new platform for dynamic metamaterial applications. xml:lang="fr"

  16. Three-Dimensional Printing in Orthopedic Surgery.

    PubMed

    Eltorai, Adam E M; Nguyen, Eric; Daniels, Alan H

    2015-11-01

    Three-dimensional (3D) printing is emerging as a clinically promising technology for rapid prototyping of surgically implantable products. With this commercially available technology, computed tomography or magnetic resonance images can be used to create graspable objects from 3D reconstructed images. Models can enhance patients' understanding of their pathology and surgeon preoperative planning. Customized implants and casts can be made to match an individual's anatomy. This review outlines 3D printing, its current applications in orthopedics, and promising future directions. PMID:26558661

  17. Three-dimensional quantitative flow diagnostics

    NASA Technical Reports Server (NTRS)

    Miles, Richard B.; Nosenchuck, Daniel M.

    1989-01-01

    The principles, capabilities, and practical implementation of advanced measurement techniques for the quantitative characterization of three-dimensional flows are reviewed. Consideration is given to particle, Rayleigh, and Raman scattering; fluorescence; flow marking by H2 bubbles, photochromism, photodissociation, and vibrationally excited molecules; light-sheet volume imaging; and stereo imaging. Also discussed are stereo schlieren methods, holographic particle imaging, optical tomography, acoustic and magnetic-resonance imaging, and the display of space-filling data. Extensive diagrams, graphs, photographs, sample images, and tables of numerical data are provided.

  18. Three-dimensional x-ray microtomography

    SciTech Connect

    Flannery, B.P.; Deckman, H.W.; Roberge, W.G.; D'Amico, K.L.

    1987-09-18

    The new technique of x-ray microtomography nondestructively generates three-dimensional maps of the x-ray attenuation coefficient inside small samples with approximately 1 percent accuracy and with resolution approaching 1 micrometer. Spatially resolved elemental maps can be produced with synchrotron x-ray sources by scanning samples at energies just above and below characteristic atomic absorption edges. The system consists of a high-resolution imaging x-ray detector and high-speed algorithms for tomographic image reconstruction. The design and operation of the microtomography device are described, and tomographic images that illustrate it performance with both synchrotron and laboratory x-ray sources are presented.

  19. Three-dimensional simulations of burning thermals

    NASA Astrophysics Data System (ADS)

    Aspden, Andy; Bell, John; Woosley, Stan

    2010-11-01

    Flame ignition in type Ia supernovae (SNe Ia) leads to isolated bubbles of burning buoyant fluid. As a bubble rises due to gravity, it becomes deformed by shear instabilities and transitions to a turbulent buoyant vortex ring. Morton, Taylor and Turner (1956) introduced the entrainment assumption, which can be applied to inert thermals. In this study, we use the entrainment assumption, suitably modified to account for burning, to predict the late-time asymptotic behaviour of these turbulent buoyant vortex rings in SNe Ia. The theory is validated against three- dimensional simulations with adaptive mesh refinement at effective resolutions up to 4096^3.

  20. Electrode With Porous Three-Dimensional Support

    DOEpatents

    Bernard, Patrick; Dauchier, Jean-Michel; Simonneau, Olivier

    1999-07-27

    Electrode including a paste containing particles of electrochemically active material and a conductive support consisting of a three-dimensional porous material comprising strands delimiting contiguous pores communicating via passages, characterized in that the average width L in .mu.m of said passages is related to the average diameter .O slashed. in .mu.m of said particles by the following equation, in which W and Y are dimensionless coefficients: wherein W=0.16 Y=1.69 X=202.4 .mu.m and Z=80 .mu.m

  1. Intersection of three-dimensional geometric surfaces

    NASA Technical Reports Server (NTRS)

    Crisp, V. K.; Rehder, J. J.; Schwing, J. L.

    1985-01-01

    Calculating the line of intersection between two three-dimensional objects and using the information to generate a third object is a key element in a geometry development system. Techniques are presented for the generation of three-dimensional objects, the calculation of a line of intersection between two objects, and the construction of a resultant third object. The objects are closed surfaces consisting of adjacent bicubic parametric patches using Bezier basis functions. The intersection determination involves subdividing the patches that make up the objects until they are approximately planar and then calculating the intersection between planes. The resulting straight-line segments are connected to form the curve of intersection. The polygons in the neighborhood of the intersection are reconstructed and put back into the Bezier representation. A third object can be generated using various combinations of the original two. Several examples are presented. Special cases and problems were encountered, and the method for handling them is discussed. The special cases and problems included intersection of patch edges, gaps between adjacent patches because of unequal subdivision, holes, or islands within patches, and computer round-off error.

  2. Two component-three dimensional catalysis

    DOEpatents

    Schwartz, Michael; White, James H.; Sammells, Anthony F.

    2002-01-01

    This invention relates to catalytic reactor membranes having a gas-impermeable membrane for transport of oxygen anions. The membrane has an oxidation surface and a reduction surface. The membrane is coated on its oxidation surface with an adherent catalyst layer and is optionally coated on its reduction surface with a catalyst that promotes reduction of an oxygen-containing species (e.g., O.sub.2, NO.sub.2, SO.sub.2, etc.) to generate oxygen anions on the membrane. The reactor has an oxidation zone and a reduction zone separated by the membrane. A component of an oxygen containing gas in the reduction zone is reduced at the membrane and a reduced species in a reactant gas in the oxidation zone of the reactor is oxidized. The reactor optionally contains a three-dimensional catalyst in the oxidation zone. The adherent catalyst layer and the three-dimensional catalyst are selected to promote a desired oxidation reaction, particularly a partial oxidation of a hydrocarbon.

  3. Nanowired three-dimensional cardiac patches

    NASA Astrophysics Data System (ADS)

    Dvir, Tal; Timko, Brian P.; Brigham, Mark D.; Naik, Shreesh R.; Karajanagi, Sandeep S.; Levy, Oren; Jin, Hongwei; Parker, Kevin K.; Langer, Robert; Kohane, Daniel S.

    2011-11-01

    Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds. These biomaterials, which are usually made of either biological polymers such as alginate or synthetic polymers such as poly(lactic acid) (PLA), help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches.

  4. In-lab three-dimensional printing

    PubMed Central

    Partridge, Roland; Conlisk, Noel; Davies, Jamie A.

    2012-01-01

    The development of the microscope in 1590 by Zacharias Janssenby and Hans Lippershey gave the world a new way of visualizing details of morphogenesis and development. More recent improvements in this technology including confocal microscopy, scanning electron microscopy (SEM) and optical projection tomography (OPT) have enhanced the quality of the resultant image. These technologies also allow a representation to be made of a developing tissue’s three-dimensional (3-D) form. With all these techniques however, the image is delivered on a flat two-dimensional (2-D) screen. 3-D printing represents an exciting potential to reproduce the image not simply on a flat screen, but in a physical, palpable three-dimensional structure. Here we explore the scope that this holds for exploring and interacting with the structure of a developing organ in an entirely novel way. As well as being useful for visualization, 3-D printers are capable of rapidly and cost-effectively producing custom-made structures for use within the laboratory. We here describe the advantages of producing hardware for a tissue culture system using an inexpensive in-lab printer. PMID:22652907

  5. Nanowired three-dimensional cardiac patches.

    PubMed

    Dvir, Tal; Timko, Brian P; Brigham, Mark D; Naik, Shreesh R; Karajanagi, Sandeep S; Levy, Oren; Jin, Hongwei; Parker, Kevin K; Langer, Robert; Kohane, Daniel S

    2011-11-01

    Engineered cardiac patches for treating damaged heart tissues after a heart attack are normally produced by seeding heart cells within three-dimensional porous biomaterial scaffolds. These biomaterials, which are usually made of either biological polymers such as alginate or synthetic polymers such as poly(lactic acid) (PLA), help cells organize into functioning tissues, but poor conductivity of these materials limits the ability of the patch to contract strongly as a unit. Here, we show that incorporating gold nanowires within alginate scaffolds can bridge the electrically resistant pore walls of alginate and improve electrical communication between adjacent cardiac cells. Tissues grown on these composite matrices were thicker and better aligned than those grown on pristine alginate and when electrically stimulated, the cells in these tissues contracted synchronously. Furthermore, higher levels of the proteins involved in muscle contraction and electrical coupling are detected in the composite matrices. It is expected that the integration of conducting nanowires within three-dimensional scaffolds may improve the therapeutic value of current cardiac patches. PMID:21946708

  6. Three-dimensional television: a broadcaster's perspective

    NASA Astrophysics Data System (ADS)

    Jolly, S. J. E.; Armstrong, M.; Salmon, R. A.

    2009-02-01

    The recent resurgence of interest in the stereoscopic cinema and the increasing availability to the consumer of stereoscopic televisions and computer displays are leading broadcasters to consider, once again, the feasibility of stereoscopic broadcasting. High Definition Television is now widely deployed, and the R&D departments of broadcasters and consumer electronics manufacturers are starting to plan future enhancements to the experience of television. Improving the perception of depth via stereoscopy is a strong candidate technology. In this paper we will consider the challenges associated with the production, transmission and display of different forms of "three-dimensional" television. We will explore options available to a broadcaster wishing to start a 3D service using the technologies available at the present time, and consider how they could be improved to enable many more television programmes to be recorded and transmitted in a 3D-compatible form, paying particular attention to scenarios such as live broadcasting, where the workflows developed for the stereoscopic cinema are inapplicable. We will also consider the opportunities available for broadcasters to reach audiences with "three-dimensional" content via other media in the near future: for example, distributing content via the existing stereoscopic cinema network, or over the Internet to owners of stereoscopic computer displays.

  7. Three-dimensional image signals: processing methods

    NASA Astrophysics Data System (ADS)

    Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

    2010-11-01

    Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

  8. On three-dimensional dilational elastic metamaterials

    NASA Astrophysics Data System (ADS)

    Bückmann, Tiemo; Schittny, Robert; Thiel, Michael; Kadic, Muamer; Milton, Graeme W.; Wegener, Martin

    2014-03-01

    Dilational materials are stable, three-dimensional isotropic auxetics with an ultimate Poisson's ratio of -1. Inspired by previous theoretical work, we design a feasible blueprint for an artificial material, a metamaterial, which approaches the ideal of a dilational material. The main novelty of our work is that we also fabricate and characterize corresponding metamaterial samples. To reveal all modes in the design, we calculate the phonon band structures. On this basis, using cubic symmetry we can unambiguously retrieve all different non-zero elements of the rank-four effective metamaterial elasticity tensor from which all effective elastic metamaterial properties follow. While the elastic properties and the phase velocity remain anisotropic, the effective Poisson's ratio indeed becomes isotropic and approaches -1 in the limit of small internal connections. This finding is also supported by independent, static continuum-mechanics calculations. In static experiments on macroscopic polymer structures fabricated by three-dimensional printing, we measure Poisson's ratios as low as -0.8 in good agreement with the theory. Microscopic samples are also presented.

  9. Three-dimensional fluorescence lifetime tomography

    SciTech Connect

    Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

    2005-04-01

    Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores.

  10. Three-dimensional flow in Kupffer's Vesicle.

    PubMed

    Montenegro-Johnson, T D; Baker, D I; Smith, D J; Lopes, S S

    2016-09-01

    Whilst many vertebrates appear externally left-right symmetric, the arrangement of internal organs is asymmetric. In zebrafish, the breaking of left-right symmetry is organised by Kupffer's Vesicle (KV): an approximately spherical, fluid-filled structure that begins to form in the embryo 10 hours post fertilisation. A crucial component of zebrafish symmetry breaking is the establishment of a cilia-driven fluid flow within KV. However, it is still unclear (a) how dorsal, ventral and equatorial cilia contribute to the global vortical flow, and (b) if this flow breaks left-right symmetry through mechanical transduction or morphogen transport. Fully answering these questions requires knowledge of the three-dimensional flow patterns within KV, which have not been quantified in previous work. In this study, we calculate and analyse the three-dimensional flow in KV. We consider flow from both individual and groups of cilia, and (a) find anticlockwise flow can arise purely from excess of cilia on the dorsal roof over the ventral floor, showing how this vortical flow is stabilised by dorsal tilt of equatorial cilia, and (b) show that anterior clustering of dorsal cilia leads to around 40 % faster flow in the anterior over the posterior corner. We argue that these flow features are supportive of symmetry breaking through mechano-sensory cilia, and suggest a novel experiment to test this hypothesis. From our new understanding of the flow, we propose a further experiment to reverse the flow within KV to potentially induce situs inversus. PMID:26825450